Pre-proof temperature controlling assembly

The present invention relates to a pre-proof temperature controlling assembly associated with an off-press apparatus for laminating an image sheet to an image receiving substrate and, more particularly, for laminating a plurality of image sheets to the receiving substrate and then laminating a portion of the receiving substrate to a display sheet.

 

What is claimed is:

1. In an off-press apparatus for laminating an image sheet to an image receiving substrate supported on a carrier plate, the apparatus comprising:

a laminator comprising:

a support frame having a right frame and a left frame;

a first lamination roller assembly rotatably mounted between the right frame and the left frame;

a second lamination roller assembly rotatably mounted between the right frame and the left frame parallel or substantially parallel to the first roller assembly forming a nip between the roller assemblies;

means for rotating the first roller assembly and/or the second roller assembly;

means for heating the first lamination roller assembly and the second lamination roller assembly to about a first temperature T1; and

a housing for substantially enclosing the first lamination roller assembly, the second lamination roller assembly, and the heating means, the housing having a housing inlet and a housing outlet, the housing retaining heat generated by the heating means within the housing generally at a second temperature T2 below the first temperature T1;

a sheet preparation and feed table having an end mounted to the laminator adjacent the housing inlet; and

a sheet output receiving table having an end mounted to the laminator adjacent the housing outlet; the improvement comprising:

a pre-proof temperature controlling assembly comprising:

a tray with a top surface and a bottom surface, the top surface extending from the housing inlet to about the nip such that when an image sheet is placed or stacked on an image receiving substrate on a carrier plate on the table and the stacked sheet, substrate and carrier plate are slid along the table into the housing inlet along the top surface of the tray into the nip between the first roller assembly and the second roller assembly, the roller assemblies will transport the stacked sheet, substrate and carrier plate between the roller assemblies, laminate the sheet and substrate together and transport the laminated sheet and substrate and the carrier plate out the housing outlet onto the sheet output receiving table; and

means for controlling the temperature of the stacked sheet, substrate and carrier plate on the tray at about a third temperature T3 above room temperature T4 and below the second temperature T2 while the stacked sheet, substrate and carrier plate are being fed to and then transported between the roller assemblies.

2. In an off-press apparatus for laminating an image sheet to an image receiving substrate supported on a carrier plate, the apparatus comprising;

a laminator comprising:

a support frame having a right frame and a left frame:

a first lamination roller assembly rotatably mounted between the right frame and the left frame;

a second lamination roller assembly rotatably mounted between the right frame and the left frame parallel or substantially parallel to the first roller assembly forming a nip between the roller assemblies;

means for rotating the first roller assembly and/or the second roller assembly;

means for heating the first lamination roller assembly and the second lamination roller assembly to about a first temperature T1; and

a housing for substantially enclosing the first lamination roller assembly, the second lamination roller assembly, and the heating means, the housing having a housing inlet and a housing outlet, the housing retaining heat generated by the heating means within the housing generally at a second temperature T2 below the first temperature T1;

a sheet preparation and feed table having an end mounted to the laminater adjacent the housing inlet; and

a sheet output receiving table having an end mounted to the laminater adjacent the housing outlet; the improvement comprising:

a pre-proof temperature controlling assembly comprising:

a tray with a top surface and a bottom surface, the top surface extending from the housing inlet to about the nip such that when an image sheet is placed or stacked on an image receiving substrate on a carrier plate on the table and the stacked sheet, substrate and carrier plate are slid along the table into the housing inlet along the top surface of the tray into the nip between the first roller assembly and the second roller assembly, the roller assemblies will transport the stacked sheet, substrate and carrier plate between the roller assemblies, laminate the sheet and substrate together and transport the laminated sheet and substrate and the carrier plate out the housing outlet onto the sheet output receiving table; and

means for controlling the temperature of the stacked sheet, substrate and carrier plate on the tray at about a third temperature T3 above room temperature T4 and below the second temperature T2 while the stacked sheet, substrate and carrier plate are being fed to and then transported between the roller assemblies, wherein the temperature controlling means comprises:

a first air blower having a first blower outlet and a first blower inlet positioned to receive air at about a fourth temperature below the third temperature from outside the housing;

a second air blower having a second blower outlet and a second blower inlet positioned to receive air at about the second temperature from inside the housing; and

a manifold having at least a third outlet and connected to the first outlet and the second outlet for directing air from the first blower and the second blower across the bottom surface of the tray and out the third outlet(s) to control the temperature of the tray and, thus, the stacked sheet, substrate and carrier plate slid on the tray.

3. The off-press apparatus of claim 2, wherein the temperature controlling means further comprises:

means in the manifold for directing air from the first outlet away from the second blower and for directing air from the second outlet away from the first blower.

4. The off-press apparatus of claim 2, wherein the temperature controlling means further comprises:

means for controlling the operation of the first blower and the second blower such that the first blower and the second blower operate alternately to maintain the temperature of the tray substantially at the third temperature.

5. The off-press apparatus of claim 2, wherein the manifold comprises

a first duct having a first inlet, a second inlet and a plurality of outlets, the first duct first inlet connected to the first blower outlet and the first duct second inlet connected to the second blower outlet;

a second duct and the bottom surface of the tray defining a plurality of chambers, each of the chambers having an inlet and an outlet, one of the chamber inlets connected to each one of the plurality of first duct outlets such that air blown through the chambers cool or heat the tray; and

a plurality of third ducts, each one of the third ducts having an inlet and an outlet, one of the third duct inlets connected to each one of the chamber outlets, the third duct outlets positioned to exhaust air to the environment outside of the housing.

6. The off-press apparatus of claim 1, wherein the temperature controlling means further comprises:

a pair of roller supports, one of the roller supports mounted on each side of the tray transverse to the direction of feeding a stacked sheet, substrate and carrier plate to the nip, each support having a plurality of bearing retaining slots; and

a plurality of non-lamination roller assemblies, each one of the non-lamination roller assemblies having a roller, shafts and bearings, the rollers extending above and transverse to the tray, the shafts extending out ends of the rollers and the bearings rotatably supported on the shafts and retained in the bearing retaining slots,

such that when the stacked sheet, substrate and carrier plate are slid along the top surface of the tray towards the nip, the non-lamination roller assemblies apply a slight force on the stacked sheet, substrate and carrier plate maintaining it in contact with the tray.

7. The off-press apparatus of claim 2, wherein the tray includes a plurality of thermally conductive fins extending into the manifold.

8. The off-press apparatus of claim 1, wherein the tray is made of aluminum with a hard, smooth tetrafluoroethylene coating.

9. The off-press apparatus of claim 1, wherein the first temperature T1 is about 100.degree. C., the second temperature T2 is about 40.degree.-45.degree. C., the third temperature T3 is temperature is about 35.degree. C., and the fourth temperature T4 is about 25.degree. C.

10. The off-press apparatus of claim 1, wherein the temperature controlling means cools the temperature of the tray.

11. In an off-press apparatus for laminating an image sheet to an image receiving substrate supported on a carrier plate, the apparatus comprising:

a laminator comprising:

a support frame having a right frame and a left frame;

a first lamination roller assembly rotatably mounted between the right frame and the left frame;

a second lamination roller assembly rotatably mounted between the right frame and the left frame parallel or substantially parallel to the first roller assembly forming a nip between the roller assemblies:

means for rotating the first roller assembly and/or the second roller assembly;

means for heating the first lamination roller assembly and the second lamination roller assembly to about a first temperature T1; and

a housing for substantially enclosing the first lamination roller assembly, the second lamination roller assembly, and the heating means, the housing having a housing inlet and a housing outlet, the housing retaining heat generated by the heating means within the housing generally at a second temperature T2 below the first temperature T1;

a sheet preparation and feed table having an end mounted to the laminator adjacent the housing inlet; and

a sheet output receiving table having an end mounted to the laminator adjacent the housing outlet; the improvement comprising:

a pre-proof temperature controlling assembly comprising;

a tray with a top surface and a bottom surface, the top surface extending from the housing inlet to about the nip such that when an image sheet is placed or stacked on an image receiving substrate on a carrier plate on the table and the stacked sheet, substrate and carrier plate are slid along the table into the housing inlet along the top surface of the tray into the nip between the first roller assembly and the second roller assembly, the roller assemblies will transport the stacked sheet, substrate and carrier plate between the roller assemblies, laminate the sheet and substrate together and transport the laminated sheet and substrate and the carrier plate out the housing outlet onto the sheet output receiving table; and

means for controlling the temperature of the stacked sheet, substrate and carrier plate on the tray at about a third temperature T3 above room temperature T4 and below the second temperature T2 while the stacked sheet, substrate and carrier plate are being fed to and then transported between the roller assemblies, wherein the temperature controlling means comprises:

a manifold comprising a main longitudinal chamber having a first end and a second end, a first inlet chamber connected to the main chamber first end, a second inlet chamber connected to the main chamber second end, and an outlet chamber connected to the main chamber by a passage, the first and second inlet chambers having an exterior port positioned to receive air at room temperature T4 from outside the housing and an interior port positioned to receive air at the second temperature T2 from outside the housing, the outlet chamber having an exterior port positioned to allow air to pass from the outlet chamber to the exterior of the housing;

an air blower positioned in the outlet chamber to draw air from the passage and exhaust the air out the outlet chamber exterior port; and

a flapper mechanism comprising a first flapper for controlling air flow through the first inlet chamber exterior and interior ports, a second flapper for controlling air flow through the second inlet chamber exterior and interior ports a shaft connected to the flappers, and means for rotating the shaft to control air flow through the first and second inlet chamber exterior and interior ports.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a pre-proof temperature controlling assembly associated with an off-press apparatus for laminating an image sheet to an image receiving substrate and, more particularly, for laminating a plurality of image sheets to the receiving substrate and then laminating a portion of the receiving substrate to a display sheet.

2. Description of Related Art

Reproduction of color images through printing is an involved process requiring a breakdown of an original image into a number of fundamental single color images and the eventual recombination of the single color images through multiple printings into a full color reproduction of the original. Color image reproduction typically includes the following steps.

First, using filtering and other photographic techniques a number of color separation transparencies or color separations are produced, typically four, each bearing a halftone dot and/or a continuous tone (contone) image corresponding, for instance, to magenta, cyan, yellow and black portions of the original. Second, a printing plate is made for each color separation by exposing a sensitized plate through one of the transparencies and developing the plate. Third, the printing plates are mounted on a multistage printing press which prints inks on a substrate, typically paper, sequentially and in register, one on top of another, four halftone and/or contone images corresponding to each of the color separations to create a full color reproduction of the original.

In the case of halftone images, the various colors are reproduced by the superposition of a multiplicity of dots of varying diameters and colors corresponding to the four color separations. Any deviation in the size or position of the printed dots results in color shifts in the final printed image. As a result of this reproduction process, setting up the press and printing a four color image is economically feasible typically only when employed for printing large quantities of a given original.

It is desirable to be able to predict the final image appearance before it is printed, and preferably before making printing plates by reviewing images made directly from the color separation transparencies. The art of evaluating the color separation transparencies and deciding whether the various colors have indeed been properly separated is called proofing. Proofing is a process which uses the color separations to create a colored image called a proof to visualize what the final printed image will look like typically without actually making printing plates and running the printing press. Proofing through the creation of proofs shows the printer and customer what the job will look like after printing, so changes can be made, if necessary, to the color separations before the job goes to press where it can waste expensive press time, paper and ink if it is not right. Proofs are used for many purposes including for customer approval, for checking compatibility of a number of subjects to be printed on the same plate or job, for internal quality checking and control, and for relatively small numbers of final reproductions.

For many years the only way to make proofs was to print them on a press. This involved making plates, mounting them on the press, making the press ready to run, and running a few prints. Proofs of this type are very expensive because they involve labor intensive operations and the use of expensive materials (e.g., plates) and cost intensive equipment (e.g., the press). Special proof presses have been built to eliminate the high costs of using production presses, but manpower costs are still high and special proof presses do not always reproduce the printing and visual characteristics of the production press. Furthermore, press proofing by either of these techniques takes a long time to make proofs.

Because of the time and expense to make press proofs attempts have been made to develop and use less expensive and faster alternatives to press proofs. These are usually made by photochemical or photomechanical means and are referred to as off-press, pre-press or pre-plate proofs.

Photochemical or photomechanical proofing systems typically use photosensitive elements in making proofs. These systems generally make proofs by exposing photosensitive elements to actinic radiation through one of the image bearing color separation transparencies to produce a duplicate image that is either a positive or a negative of the transparency depending on the element used. The radiation may make soluble areas insoluble, insoluble areas soluble, tacky areas nontacky, or nontacky areas tacky depending on the element used. After imagewise exposure, the photosensitive element can be developed by washing out soluble areas. Then tacky areas of the element may have to be toned with a dry or liquid colorant. This process is repeated for all color separations. Then the processed elements are laminated together one at a time sometimes on a support or substrate. Protective layers may be peeled apart and removed from the elements before they are laminated to the support or other image elements. Finally, the four color images may be transferred from the support to a receptor, transfer or display sheet, such as a sheet of paper, to form the final proof.

Many photosensitive elements used for image reproduction have the disadvantage that they must be washed out by an organic solvent or aqueous base. For instance, U.S. Pat. No. 4,053,313 to Fan discloses a photosensitive element comprising a solvent-processable photosensitive layer, a tonable elastomeric layer and a support, that is processed (i.e., washed-out) by a mixture of water and organic solvent. The elements disclosed in U.S. Pat. Nos. 4,376,158 and 4,376,159 to Speckler require aqueous base for washout. Precolored diazo based photosensitive elements which are developed in a mixture of 1-propanol and water are disclosed, for example, in U.S. Pat. No. 3,671,236 to Van Beusekom, U.S. Pat. No. 4,656,114 to Cederburg and U.S. Pat. No. 4,666,817 to Sachi. Use of organic solvents or aqueous bases frequently is undesirable due to flammability, toxicity, corrosion and/or waste disposal considerations. The photosensitive elements disclosed in these Fan and Speckler patents also require the developed (i.e., washed-out) elements to be toned either manually or in a toning apparatus.

Photosensitive elements are known and are being developed that do not have the above described disadvantages. Specifically, U.K. Patent publication GB 2144867 B discloses photosensitive elements having entirely aqueously developable precolored layers containing a colorant on a removable support. The U.K. patent further describes a photomechanical process for forming a multicolor image, suitable for use as an off-press proof utilizing the aqueously developable photosensitive elements. The process for preparing a multicolor image is accomplished by (1) imagewise exposure of a first one of the precolored photosensitive elements comprising an aqueously developable precolored photosensitive layer on a removable support through a first one of the color separation transparencies forming image areas and non-image areas in its aqueously developable precolored layer, (2) processing the exposed element to develop the color image by washing away the non-image areas with water, (3) laminating the image bearing element to a substrate, and then (4) peeling the removable support from the image bearing element. A second color image element is made by exposing a second precolored photosensitive element with a second one of the color separation transparencies, processing to develop the color image, laminating in register the second color image element to the first color image element on the substrate and peeling the removable support from the second color image element. By repeating the exposing, processing, laminating in register, and peeling steps two more times, a four color image can be obtained. As long as the emulsion layer of the color separation contacts the photosensitive layer in the photosensitive element during the exposure step as is preferred, the process described in this U.K. patent results in a wrong reading proof on the substrate. This means that the image on the substrate is a mirror image of that captured in the color separations.

Often it is desirable to view the multicolored image on a receptor or a transfer sheet, such as paper, which is the same as or similar to that which will be used in the final printing run. In this case, the multicolor image is transferred to the desired receptor by laminating and then peeling away the substrate. This results in a right reading proof assuming the emulsion layer of the color separation contacts the photosensitive layer in the photosensitive element during the exposure step. A right reading proof is the same as the original image, not a mirror image.

Many apparatuses have been developed for laminating photosensitive elements. Different laminating apparatuses are designed and used for laminating different photosensitive elements. However, aqueously developable precolored photosensitive elements are a relatively recent development. As such, few apparatuses exist for use in laminating aqueously developed precolored photosensitive elements or image sheets to supports or receiving substrates.

U.S. Pat. No. 4,659,927 to Tago et al. assigned to Fuji Photo Film Co., Ltd., discloses a laminator and a method utilizing the laminator for preparing a multicolor proof on a support plate of good thermal conductivity. The laminator comprises a pair of insertion rollers for feeding superposed sheets on the support plate into the laminator, a pair of heated rollers for receiving the sheets and plate from the insertion rollers and for heating and applying pressure to the sheets and plate, and a pair of cooling rollers for cooling the sheets and plate fed from the heated rollers.

A laminator is commercially available from Fuji Photo Film Co., Ltd., for laminating aqueously developed precolored photosensitive elements or image sheets to supports or receiving substrates. The laminator includes the parts described in the aforedescribed Fuji patent. The laminator operates at one nip distance and pressure setting limiting its use with a variety of photosensitive elements, supports or receiving substrates and final transfer or display sheets. Only one of the heated rollers is driven by a motor. The other heated roller is rotated by frictional contact through the sheets sandwiched between the rollers. This causes slippage of the layers in the sheets during the laminating causing misregistration of colors in reproduced images and transfer irregularities.

U.S. Pat. No. 5,075,722 and U.S. patent application Ser. No. 07/612,975 disclose an off-press apparatus for laminating aqueously developed precolored photosensitive elements or image sheets to supports or receiving substrates using a carrier plate in the process. This laminator operates at more than one operating pressure or linear force setting enabling its use with a variety of photosensitive elements, supports or receiving substrates and final transfer or display sheets. This laminator includes means for driving a first roller assembly and a second roller assembly such that the magnitude of the tangential velocity of a point on the circumference of the first roller assembly is the same as the magnitude of the tangential velocity of a point on the circumference of the second roller assembly. This reduces slippage of the layers in the sheets during the laminating.

A difficulty associated with laminate-in-register systems, such as those disclosed in U.S. Pat. Nos. 5,075,722 and 4,659,927, is in laminating a processed color image element to the receiving substrate without causing any image distortion. Image distortion can be seen when dots of a color image of subsequent color laminations do not lay in proper position to dots of a previous layer color image. The mis-alignment or mis-registration of the dots of each color image element is referred to as registration error. Registration error becomes noticeable as a color shift when dots are mis-registered by more than half the diameter of the typical sized dot. In commercial 200 lines per inch printing, this maximum registration error would translate to about 3 microns.

A need exists to provide a method and apparatus for laminating a color image sheet to an image receiving substrate with improved registration of resulting proofs. Particularly, this need exists in off-press apparatus for laminating aqueously developed precolored photosensitive elements or image sheets to supports or receiving substrates using a carrier plate in the process.

SUMMARY OF THE INVENTION

The invention relates to an improvement in an off-press apparatus for laminating an image sheet to an image receiving substrate supported on a carrier plate, the apparatus comprising:

a laminator comprising:

a support frame having a right frame and a left frame;

a first lamination roller assembly rotatably mounted between the right frame and the left frame;

a second lamination roller assembly rotatably mounted between the right frame and the left frame parallel or substantially parallel to the first roller assembly forming a nip between the roller assemblies;

means for rotating the first roller assembly and/or the second roller assembly;

means for heating the first lamination roller assembly and the second lamination roller assembly to about a first temperature; and

a housing for substantially enclosing the first lamination roller assembly, the second lamination roller assembly, and the heating means, the housing having a housing inlet and a housing outlet, the housing retaining heat generated by the heating means within the housing generally at a second temperature below the first temperature;

a sheet preparation and feed table having an end mounted to the laminator adjacent the housing inlet; and

a sheet output receiving table having an end mounted to the laminator adjacent the housing outlet; the improvement comprising:

a pre-proof temperature controlling assembly comprising:

a tray with a top surface and a bottom surface, the top surface extending from the housing inlet to about the nip such that when an image sheet is placed or stacked on an image receiving substrate on a carrier plate on the table and the stacked sheet, substrate and carrier plate are slid along the table into the housing inlet along the top surface of the tray into the nip between the first roller assembly and the second roller assembly, the roller assemblies will transport the stacked sheet, substrate and carrier plate between the roller assemblies, laminate the sheet and substrate together and transport the laminated sheet and substrate and the carrier plate out the housing outlet onto the sheet output receiving table; and

means for controlling the temperature of the stacked sheet, substrate and carrier plate on the tray at about a third temperature above room temperature and below the second temperature while the stacked sheet, substrate and carrier plate are being fed to and then transported between the roller assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood from the following detailed description thereof in connection with accompanying drawings described as follows.

FIG. 1 is a perspective view of a first embodiment of a pre-proof temperature controlling assembly in an off-press apparatus for laminating an image sheet to an image receiving substrate supported on a carrier plate in accordance with the present invention.

FIG. 2 is a perspective view of the pre-proof temperature controlling assembly and part of a laminator included in the off-press apparatus of FIG. 1 with housing panels shown in phantom line to show internal parts.

FIG. 3 is a schematic illustration of the pre-proof temperature controlling assembly in the off-press apparatus of FIG. 1.

FIG. 4 is a perspective view of the pre-proof temperature controlling assembly with parts exploded from one another.

FIG. 5 is a perspective view of a manifold in accordance with the present invention with parts exploded from one another.

FIG. 6 is a cross sectional view generally along a first plane through a first duct network and a third chamber of the manifold.

FIG. 7 is a cross sectional view generally along a second plane parallel to the first plane and bisecting the third chamber and a 2nd third duct network of the manifold.

FIG. 8 is a cross section view of a heat sink extending from a bottom surface of a tray of the pre-proof temperature controlling assembly.

FIG. 9 is a perspective view of the pre-proof temperature controlling assembly of FIG. 1 with roller assemblies exploded away from the apparatus.

FIG. 10 is a schematic illustration of an electrical control system for the present invention.

FIG. 11 is a perspective view of a second embodiment of a pre-proof temperature controlling assembly with parts exploded from one another.

FIG. 12 is a cross sectional view generally along a first plane through the pre-proof temperature controlling assembly of FIG. 11.

FIG. 13 is a perspective view of a flapper mechanism for directing air flow in the pre-proof temperature controlling assembly of FIG. 11.

FIG. 14 is a schematic illustration of laminating by applying pressure and heat through a nip between a first roller assembly and a second roller assembly to sandwich an image sheet having one colored image together with a receiving substrate having no colored images.

FIG. 15 is a schematic illustration of laminating by applying pressure and heat through a nip between a first roller assembly and a second roller assembly to sandwich the receiving substrate having one colored image together with a transfer sheet.

FIGS. 16-18 are schematic illustrations of intermediate laminating steps in a process of forming a multicolor proof.

FIG. 19 is a schematic illustration of laminating by applying pressure and heat through a nip between a first roller assembly and a second roller assembly to sandwich the receiving substrate having four colored images together with a transfer sheet.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

A substantial contributor to registration error is from the dimensional instability of a polyester base used in each of the color image elements and the receiving substrate. Inherently the polyester base changes dimensions, i.e., expands, when heated, but eventually returns close to its original dimensions when returned to room temperature. Since during lamination, the color image of the color image element transfers from the element to the receiving substrate, the position of the dots of the color image, i.e., registration, is influenced by the dimensional changes that occurs for each base.

The dimensional stability of the color image elements and the receiving substrate is influenced by the thermal energy, i.e., heat, applied to the lamination stack, i.e., the color image element and receiving substrate. If the applied thermal energy experienced by the lamination stack is not uniform, the dimensional instabilities of the element and the substrate cause distortion of the image which results in registration error in a proof. Prior to the present invention, non-uniformities in the lamination process have been mitigated primarily by assuring that temperature and pressure profiles of the nip rollers in the laminator are constant.

However, the use of a carrier plate in an off-press laminating apparatus introduces a non-uniformity to the thermal energy applied to the lamination stack during lamination. As the lamination stack passes through heated nip rollers in the laminator, heat wicks up, i.e., travels, the carrier plate and preheats the lamination stack. The heat wicking results in the trailing portion of the lamination stack experiencing the applied thermal energy for a longer period of time than the leading portion of the lamination stack. This phenomena causes an ever increasing applied thermal energy down the length of the lamination stack.

It has been discovered that a pre-proof temperature controlling assembly 8 (FIG. 1) in accordance with the present invention effectively prevents heat wicking up the carrier plate and maintains the uniformity of the applied thermal energy to all locations on the lamination stack. The result is a reduction in the dimensional changes of the color image elements and receiving substrate which in turn improves registration of the proof.

Referring to FIG. 1, there is illustrated a perspective view of the pre-proof temperature controlling assembly 8 in an off-press laminating apparatus 10 for laminating an image sheet to an image receiving substrate supported on a carrier plate in accordance with the present invention. The term "off-press" is meant to be equivalent to the terms pre-press and pre-plate. The off-press laminating apparatus 10 generally comprises a laminator 12, a sheet preparation and feed table 14 and a sheet output receiving table 16.

The laminator 12 comprises a front side 20, a rear side 22, a left side 24 and a right side 26. An operator control pad 18 is conveniently located on the laminator 12. FIG. 2 is perspective view showing the pre-proof temperature controlling assembly 8 and part of the laminator 12 with housing panels 28 shown in phantom lines to show internal parts. FIG. 3 is a schematic illustration of an image sheet 30 on an image receiving substrate 32 supported on a carrier plate 34 partially on the pre-proof temperature controlling assembly 8 in the off-press apparatus 10.

As best seen in FIG. 2, the laminator 12 comprises a support frame having a right frame 36 and a left frame 38. The laminator 12 further includes a first lamination roller assembly 40 and a second lamination roller assembly 42. The first lamination roller assembly 40 is rotatably mounted between the right frame 36 and the left frame 38. The second lamination roller assembly 42 is rotatably mounted between the right frame 36 and the left frame 38 parallel or substantially parallel to the first roller assembly 40 forming a nip 44 between the roller assemblies 40,42. See FIG. 3. The laminator 12 further includes means 46 for rotating the first roller assembly 40 and the second roller assembly 42. The rotating means 46 can include gears and chains driven by a motor assembly possibly through the use of a gear box. The laminator 12 further includes means 48,50 for heating the first lamination roller assembly 40 and the second lamination roller assembly 42 to about a first temperature T1. The heating means 48,50 can comprise heaters or heater elements positioned in the first and second roller assemblies 40,42. A housing 52 substantially encloses the support frame 36,38, the first lamination roller assembly 40, the second lamination roller assembly 42, and the heating means 48,50. The housing 52 can comprise a plurality of housing panels 27,28,29. Referring to FIG. 3, the housing 52 has a housing inlet 54 and a housing outlet 56. The housing 52 serves to retain the heat generated by the heating elements 48,50 such that the air temperature within the housing 52 when the laminator 12 is operating is at a second temperature T2.

Referring to FIGS. 1 and 3, the sheet preparation and feed table 14 has a first end mounted to the laminator 12 adjacent the housing inlet 54. The table 14 extends from the front side 20 of the laminator 12 and is supported at a second end remote from the laminator 12 by legs or a support assembly 58. The sheet output receiving table 16 has a first end mounted to the laminator 12 adjacent the housing outlet 56. The table 16 extends from the rear side 22 of the laminator 12 and is supported at a second end remote from the laminator 12 by legs or a support assembly 60.

FIG. 4 is a perspective view of the pre-proof temperature controlling assembly 8 with parts exploded from one another. The pre-proof temperature controlling assembly 8 comprises a tray 62 with a top surface 64 and a bottom surface 66. Referring back to FIGS. 2 and 3, the top surface 64 extends from the housing inlet 54 to about the nip 44 such that when an image sheet 30 is placed or stacked on an image receiving substrate 32 on a carrier plate 34 on the table 14 and the stacked sheet 30, substrate 32 and carrier plate 34 are slid along the table 14 into the housing inlet 54 along the top surface 64 of the tray 62 into the nip 44 between the first roller assembly 40 and the second roller assembly 42, the roller assemblies 40,42 will transport the stacked sheet 30, substrate 32 and carrier plate 34 between the roller assemblies 40,42, laminate the sheet 30 and substrate 32 together and transport the laminated sheet 30 and substrate 32 and the carrier plate 34 out the housing outlet 56 onto the sheet output receiving table 16.

Referring to FIGS. 4 and 5, the pre-proof temperature controlling assembly 8 further comprises means 68 for controlling the temperature of the stacked sheet 30, substrate 32 and carrier plate 34 on the tray 62 at about a third temperature T3 above room temperature and below the second temperature while the stacked sheet 30, substrate 32 and carrier plate 34 are being fed to and then transported between the roller assemblies 40,42. Preferably, the temperature controlling means 68 comprises a first air blower 70, a second air blower 72, a manifold 74 and an electrical control system 76.

FIG. 6 is a cross sectional view generally along a first plane through the manifold 74. FIG. 7 is a cross sectional view through the manifold 74 generally along a second plane parallel to the first plane.

Referring to FIG. 6, the first air blower 70 can have a first blower outlet 76 and a first blower inlet 78 positioned to receive air at about a fourth 10 temperature T4 below the third temperature from outside the housing 52. (See FIG. 3.) The second air blower 72 can have a second blower outlet 80 and a second blower inlet 82 positioned to receive air at about the second temperature T2 from inside the housing 52. (Again see FIG. 3.)

Referring to FIGS. 5 and 6, the manifold 74 can comprise a first duct network or duct 90, a second duct network or duct 92 and a plurality of third duct networks or ducts 94A-D. The first duct 90 has a first inlet 96, a second inlet 98 and a plurality of outlets 100A-D. The first duct first inlet 96 is connected to the first blower outlet 76. The first duct second inlet 98 is connected to the second blower outlet 80. The second duct 92 and the bottom surface 66 of the tray 62 define a plurality of chambers 102A-D. There can be any number of chambers 102. The embodiment illustrated in the Figures has a first chamber 102A, a second chamber 102B, a third chamber 102C, and a fourth chamber 102D. Each of the chambers 102A-D has an inlet 104A-D and an outlet 106A-D. One of the chamber inlets 104A-D is connected to each one of the plurality of first duct outlets 100A-D such that air blown through the chambers 102A-D cools or heats the tray 62. Each one of the third ducts 94A-D has an inlet 108A-D and an outlet 110A-D. One of the third duct inlets 108A-D is connected to each one of the chamber outlets 106A-D. If there are four chamber outlets 106A-D as illustrated in the Figures, there are four third ducts, i.e., a 1st third duct 94A, a 2nd third duct 94B, a 3rd third duct 94C and a 4th third duct 94D. The third duct outlets 110A-D are positioned to exhaust air to the environment outside of the housing 52. (See FIG. 3.)

Referring to FIGS. 4 and 6, the temperature controlling means 68 preferably further comprises means 112 in the manifold 74 for directing air from the first blower outlet 76 away from the second blower outlet 80 and for directing air from the second blower outlet 80 away from the first blower outlet 76. Preferably, the directing means 112 is a flapper valve comprising a light weight flat door 114 connected by a hinge 116 in the first duct 90 adjacent the first duct first inlet 96 and the first duct second inlet 98. When air is blown into the first duct first inlet 96 and air is not blown into the first duct second inlet 98, the flapper valve 112 is blown away from the first duct first inlet 96 and towards, thereby closing or blocking, the first duct second inlet 98. This directs the air out the first duct outlets 100A-D, rather than allowing the air to escape through the first duct second inlet 98. When air is blown into the first duct second inlet 98 and air is not blown into the first duct first inlet 96, the flapper valve 112 is blown away from the first duct second inlet 98 and towards, thereby closing or blocking, the first duct first inlet 96. Again this directs the air out the first duct outlets 100A-D, rather than allowing the air to escape through the first duct first inlet 96. When air is blown into the first duct first inlet 96 and air is simultaneously blown into the first duct second inlet 98, the flapper valve 112 is forced to an intermediate position allowing air to be blown in from both the first duct first inlet 96 and the first duct second inlet 98.

Referring to FIGS. 4, 6, 7 and 8, the tray 62 includes at least one thermally conductive heat sink 118 extending from the bottom surface 66 of the tray 62 into the manifold 74. Each heat sink 118 has ribs or fins 120 projecting into one of the chambers 102A-D. Preferably, the fins 120 extend longitudinally in the direction of air flow through the chambers 102A-D. The tray 62 and heat sinks 118 can be aluminum and cast or otherwise formed as one unit. Alternatively, as shown in the Figures, the tray 62 can be made of an aluminum plate 122 with a hard, smooth tetrafluoroethylene coating 124. Threaded studs 126 can be fixed to and extend from the bottom surface of the aluminum plate 122 which receive nuts 127 to secure individual aluminum heat sinks 118 to the bottom surface 66 of the tray 62 so as one of the heat sinks 118 extends into each one of the chambers 102A-D. A thin thermally conductive putty layer 128 can be applied between the tray 62 and the heat sinks 118 to increase the thermal conductivity between them.

Referring to FIG. 9, preferably, the temperature controlling means 68 further comprises a pair of roller supports 130 supporting a plurality of non-lamination roller assemblies 132. One of the roller supports 130 can be mounted on each side of the tray 62 transverse to the direction of feeding a stacked sheet 30, substrate 32 and carrier plate 34 to the nip 44. Each support 130 can have a plurality of bearing retaining slots 134. Each one of the non-lamination roller assemblies 132 can have a roller, shafts and bearings. The rollers can extend above and transverse to the tray 62. The shafts can extend out ends of the rollers. The bearings can be rotatably supported on the shafts and retained in the bearing retaining slots 134. When the stacked sheet 30, substrate 32 and carrier plate 34 are slid along the top surface 64 of the tray 62 towards the nip 44, the non-lamination roller assemblies 132 apply a slight force on the stacked sheet 30, substrate 32 and carrier plate 34 maintaining the carrier plate 34 in contact with the tray 62. This increases and ensures good thermal conductivity between the tray 62 and the carrier plate 34.

The electrical control system 76 can comprise means for controlling the operation of the first blower 70 and the second blower 72 to maintain the temperature of the tray 62 substantially at the third temperature. Preferably, the first temperature is about 100.degree. C. (i.e., degrees Celsius), the second temperature is about 40.degree.-45.degree. C., the third temperature is about 35.degree. C., and the fourth temperature is about 25.degree. C.. This effectively cools the temperature of the tray 62. In a first embodiment, the electrical control system 76 operates the first blower 70 and the second blower 72 alternately at constant flow rates to maintain the temperature of the tray 62 substantially at the third temperature. In a second embodiment, both blowers can have variable flow rates. In a third embodiment, one of the blowers can be constantly blowing at a constant flow rate and the other blower can be turned on and off at a constant flow rate to control the temperature of the tray 62.

FIG. 10 is a schematic illustration of the first embodiment of the electrical control system 76 for the pre-proof temperature controlling assembly 8 of the present invention. The electrical control system includes a programmable logic controller (PLC) 230 connected to a power distribution network 232 or the like through a step down transformer 234 which converts voltage, such as, from 220 Volts to 115 Volts at 50 Watts. A suitable PLC 230 that can be used in the present invention is commercially available under model number D100CR14 from Cutler Hammer with offices in Philadelphia, Pa. The suitable power distribution network 232 may include fuse blocks, terminal blocks and interconnections between components of the control system. For instance, the power distribution network 232 may be connectable by an input cable 236 to a power supply, such as a 220 Volt 16 Amp AC power supply (not depicted). Alternatively, the control system 76 could be designed to receive power from a 120 Volt AC power supply in which case the step down transformer 234 would not be needed.

The key pad 18 is connected by lines 262,264 to provide and receive signals from the PLC 230. A DC power supply 238 is connected between the input cable 236 and the control or key pad 18. The DC power supply 238 continuously provides DC power to all soft-on/soft-off power circuits in the control system 76. A power switching device 256 is connected by a line 255 between the control or key pad 18 and the power distribution network 232. A suitable power switching device 256 that can be used in the present invention is commercially available under model number CE15DN2B from Cutler Hammer. The power switching device 256 is a soft-on/soft-off circuit having several relays and a large contactor to handle the power. The soft-on/soft-off circuit 256 provides DC power to items connected to the DC power supply 238. A line 258 also interconnects the power switching device 256 with an input to the PLC 230.

The electrical control system 76 includes an electrical temperature control subsystem 290. The electrical temperature control subsystem 290 comprises a temperature controller 292 connected to a first line 294 which in turn is connected to the power distribution network 232. The first blower 70 and the second blower are connected in lines 296 and 298, respectively, in parallel between the temperature controller 292 and a line 300 which in turn is connected to the power distribution network 232. A temperature sensor or thermocouple 302 is positioned to sense the temperature of the tray 62 and is connected to provide signals representative of the sensed temperature to the temperature controller 292. Suitable temperature controllers 292 that can be used in the present invention are commercially available under model number PYZ4TDY1-IV from Fuji Electric of Japan. The temperature controller 292 includes an alarm circuit 306. The alarm circuit 306 is connected in series between the DC power supply 238 and the PLC 230.

In operation, the apparatus 10 is activated by pressing a "power on/off" toggle switch 252 which sends a signal to the device 256 over line 255. Then the device 256 applies power to the entire control system 76.

The temperature controller 292 also switches on in response to pressing the "power on" switch 252. The temperature controller 292 controls the temperature of the tray 62 based on manually inputted preset values and feedback from the temperature sensor 302.

A high temperature preset and a low temperature preset can be inputted to the alarm circuit 306. The alarm circuit 306 monitors the temperature being fed back from the temperature contact sensor 302. When the temperature of the tray 62 is between the inputted high and low temperature presets for the alarm circuit 306, the alarm circuit 306 is activated and closes a switch creating an electrical path through the alarm circuit 306. When the alarm circuit 306 is activated, a signal is sent from the alarm circuit 306 to the PLC 230. If the PLC 230 does not receive a signal from the alarm circuit 306, the PLC 230 sends a signal to activate an "error" lamp 246 indicating there is a temperature problem.

FIG. 11 is a perspective view of a second embodiment of a pre-proof temperature controlling assembly 308. The second assembly 308 can be used in the off-press laminating apparatus 10, instead of and to perform the functions of the first assembly 8. Like the first assembly 8, the second pre-proof temperature controlling assembly 308 comprises a tray 310 and means 312 for controlling the temperature of the stacked sheet, substrate and carrier plate on the tray 310 at about the third temperature T3 while the stacked sheet, substrate and carrier plate are being fed to and then transported between the roller assemblies 40, 42.

The tray 310 has a top surface 314 and a bottom surface 316. The top surface extends from the inlet 54 to about the nip 44 and functions like the top surface 64 of the first assembly 8. The tray 310 includes ribs or fins 318 extending from the bottom surface 316 and extending transverse to the direction that the stacked sheet, substrate and carrier plate are slid and transported. The tray 310 and fins 318 are formed as one piece, such as being cast or extruded. The tray 310 and fins 318 are aluminum. A hard, smooth tetrafluorethylene coating can be applied to the top surface 314.

The controlling means 312 comprises an air blower 320, a manifold 322, and a flapper mechanism 324. The air blower 320 is preferably a motorized impeller. The manifold 322 comprises or defines a main longitudinal chamber 326 which extends transverse to the direction that the stacked sheet, substrate and carrier plate are moved. The fins 318 extend in the main chamber 326. The manifold 322 further comprises or defines a first inlet chamber 328 and a second inlet chamber 330. The first inlet chamber 328 connects to a first end of the main chamber 326. The second inlet chamber 330 connects to a second end of the main chamber 326. FIG. 12 is a cross sectional view through the first inlet chamber 328.

Each inlet chamber 328, 330 includes an exterior port 331 positioned to receive air at T3 from outside the housing 52. Each inlet chamber 328, 330 also includes an interior port 334 positioned to receive air at T2 from inside the housing 52. Preferably, the inlet chambers 328, 330 are positioned below ends of the main chamber 326.

The manifold 322 further includes an outlet chamber 332 below and to the main chamber 326 connected by a passage 334. The passage 334 is spaced about mid way from the ends of the main chamber 326. The outlet chamber 332 has an exterior port 336 positioned to allow air to pass from the outlet chamber 332 to outside the housing 52. The impeller 320 is positioned in the outlet chamber 332 to draw air from the passage 334 and to exhaust air through the exterior port 336 exterior to the housing 52.

The flapper mechanism 324 is best shown in FIG. 13. The flapper mechanism 324 comprises a first flapper 338 for controlling air flow through ports 331, 334 in inlet chamber 328, a second flapper 340 for controlling air flow through the ports 331, 334 in inlet chamber 328, 330, and a shaft 342 connected to the flappers 338, 340. A motor assembly 344 is adapted to rotate a motor gear 346 on the motor shaft. The motor gear 346 connects to and drives a shaft gear 348 on the shaft 342. Thus, when the motor assembly 344 is activated, it rotates the motor gear 346 which rotates the shaft gear 348 which rotates the shaft 342 and the flappers 338, 340. The shaft 342 can be one piece or a plurality of shaft segments connected by couplers 343.

The flapper mechanism 324 includes means 350 for limiting rotation of the shaft 342 and flappers 338, 340 by deactivating the motor assembly 344 when the flappers 338, 340 close the exterior ports 331 and when the flappers 338, 340 close the interior ports 334. The deactivating means 350 may include a first limit switch 352, a second limit switch 354, a first cam 356 on the shaft 342, a second cam 358 on the shaft 342. The first and second cams 356, 358 have recesses 360. A first detent 362 on the switch 352 extend into the recess 360 on the cam 356 deactivating rotation in one direction such as when the flappers 338, 340 close exterior ports 332. A second detent 364 on the other switch 354 extends into the recess 360 on the cam 358 deactivating rotation in the other direction such as when the flappers 338, 340 close interior ports 334.

The flapper mechanism 324 also includes means 366 for controlling the position, i.e., rotation, of the shaft 342 and the flappers 338, 340. The controlling means 366 may include a potentiometer 368, a pot gear 370 connected to a pot shaft, and a shaft gear 372 connected to the pot gear 370. The potentiometer 368 provides an electrical signal such as to a computer or other control system, indicative of the position, i.e., rotation, of the shaft 342. In response to this signal and other inputs, such as a signal representing the temperature of the tray 310 from a temperature sensor (not depicted), the computer or other control system can be programmed to control the motor assembly 344 to position the flappers 338, 340 to maintain the temperature of the tray 310 at a predetermined temperature.

Referring to FIG. 11, a sensor 374 can be provided at the leading edge of the tray 310. The sensor can be connected to the computer to cause the flappers 338, 340 to close the exterior ports for a predetermined time period to increase the temperature of the tray 310 when a carrier plate initially passes onto the tray 310.

The laminator 12 can be like the laminator disclosed in U.S. Pat. No. 5,075,722 and/or U.S. patent application Ser. No. 07/612,975 with the exceptions expressly noted in this specification. Suitable parts for the laminator 12 including the lamination roller assemblies 40,42, the rotating means 46, the heating means 48,50, and much of the electrical control system 76 are disclosed in more detail in U.S. Pat. No. 5,075,722 and U.S. patent application Ser. No. 07/612,975 which are hereby incorporated by reference.

A preferred carrier plate suitable for use in this invention is described in co-pending U.S. patent application Ser. No. (Attorney docket number IM-0827) and filed the same day as this specification.

The off-press apparatus 10 of the present invention can be used to perform an off-press method for laminating at least one color image sheet to an image receiving substrate and then transferring the color image(s) from the receiving substrate to a transfer sheet to form a proof.

Specifically, referring to FIG. 14, a first precolored photosensitive element 410 comprising a fir