JPS626257A - Image formation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides surface waves of rupturable photosensitive microcapsules.
The present invention relates to a condensation system using an imaging sheet with i, and more particularly to a method and apparatus for rupturing microcapsules on such a condensation sheet.

No. 4,4 A O,846 and No. 4,399,209, filed by the present applicant, a photosensitive layer consisting of microcapsules containing a photosensitive composition in the internal phase is imagewise exposed to actinic radiation. An imaging system is disclosed in which the microcapsules are subjected to a uniform bursting force, thus causing the microcapsules to rupture and imagewise release of the internal phase. The imaging system is particularly advantageous because it does not rely on employing wet processing solutions for imaging in an entirely dry system. Imaging color-forming materials, such as near-colorless colorants, are typically associated with microcapsules. When the microcapsules are ruptured, the colorant reacts imagewise with the developer material to form a colored image. In the embodiments disclosed in the aforementioned patents, the microcapsules are typically broken by passing the imagewise exposed imaging sheet through a nip between a pair of parallel calendar rolls.

Although high pressure is not required to break the microcapsules, large calenders at high pressures are usually used to develop the imaged sheet. Even carefully engineered metal calender rolls can have uneven surfaces. If one roll is simply placed on top of the other, the surfaces of these rolls will not touch over the entire length of the roll.

By applying pressure to the rolls, uneven surfaces or surface irregularities are stretched and smoothed to create a uniform line of contact between the rolls. High pressure, dog-sized rolls are required to evenly distribute the burst force over the surface of the imaging sheet. If the bursting force is not evenly distributed, the imaging sheet will show an uneven image and the resulting image will have poor tonal characteristics.

Use of a pair of pinch rolls that are pressed against each other in a pressure fixing device that fixes an easily melted toner image onto paper, with one roll extending at an angle to the axis of the other roll. known to. This beveled configuration prevents any unevenness from occurring in the nipple between the rolls even as the paper passes through. However, if the bevel is too large, wrinkles or folds will form in the paper.

The bevels are completely minimized to avoid folds in the paper. If the bevel angle is small, however, the rolls must again be made to a larger diameter to ensure uniform pressure along the nip by bending the rolls. In addition to the additional weight of larger rolls, the load pressure must also be increased. Therefore, larger pressure mechanisms, higher compression resistance bearings, housings, etc. will increase the cost of the device. .

These three-dimensional mechanisms are used to overcome difficulties in the art of fixable toner images. In one type of 30-wheel mechanism, the upper roll and lower roll are a pair of pinch rolls placed parallel and horizontally without forming an oblique angle between them. A sixth support roll is provided in cross contact with the lower roll. The support roll is elastically downwardly directed toward the lower roll such that a pressure mechanism causes the lower roll of the pair of pinch rolls to abut the upper roll under pressure to form a nip along the contact that passes the paper. Pressed by The bending of the lower roll is such that both the lower roll and the support roll are smaller than the diameter of the upper roll, and the upper roll is parallel to the lower roll, so the cross angle of the support roll with respect to the lower roll is such that the paper does not wrinkle as it rolls back into the nip. adjusted by.

According to the present invention, the exposed imaging sheet disclosed in the aforementioned patents is processed to rupture the microcapsules on the sheet by a pair of pinch rolls or a pair of pinch rolls 8 and a support roll.

In this case, at least one pair of pinch rolls are positioned with the rolls at an angle to each other. Beveled 20-1 and 30-1 mechanisms are known in the art of fusing fusible toner images, such as those described in U.S. Pat. No. 4,54
No. 3,234, it is particularly desirable to process imaging sheets with Applicant's imaging system because of its ability to provide uniform pressure and small diameter rolls.

The main object of the present invention is to provide a method and apparatus for developing an imaging sheet using photosensitive microcapsules.
More specifically, the present invention provides a method and apparatus for rupturing photosensitive microcapsules forming a photosensitive layer on the surface of an imaging sheet.

According to one embodiment of the invention, first and second rolls of different diameters are pivoted to side support members of the housing to form a nip therebetween. Roll centering means are provided to oblique the first and second rolls at an angle between 10' and 1°50' relative to each other. The first and second rolls are elastically pressed against each other by a sixth roll, and the first and second rolls are elastically pressed against each other by a sixth roll. The second and sixth rolls rotate. The imaged sheet to be developed then passes through a nip between the first and second rolls.

Preferably, the six rolls are rotated by driving the second and sixth rolls through surface contact with the first roll to drive the first roll. According to the invention, the third roll is supported at an oblique angle to the second roll.

According to a first alternative embodiment of the invention, the first and second rolls are provided with roll centering means pivoted on a side support member of the housing to form a nip therebetween. Bevel the first and second rolls at an angle between 10' and 1°5U'. The first and second rolls are elastically pressed against each other and rotated. The developed imaging sheet thus passes through the nip between the first and second rolls.

The rotation of the first and second rolls is preferably performed by driving the second roll through surface contact with the first roll, thereby driving the first roll.

According to a second alternative embodiment of the invention, the first and second mid-height rolls are pivoted to side support members of the housing to form a nip therebetween. The first and second mid-height rolls are pressed into contact with each other to provide a uniform bursting force over the length of the nip. The first and second medium-height rolls rotate and the imaging sheet passes through a nip formed between them to rupture the microcapsules on the imaging sheet. The concave shape of the roll compensates for bending in this embodiment of the invention.

Other objects and advantages of the present invention will become apparent from the following description.

One example of the imaging sheet that can be effectively applied in the present invention is the first
Shown in Figures A-10. In FIG. 1A, an eye-fed imaging sheet 110 is shown. Imaging sheet 110 is made of a support 112 covered with a layer of microcapsules 114. Microcapsules 114 are filled with an internal phase 116 containing a photosensitive composition. Ordinary microcapsule 114
Also contains a color-forming substance, which is integrated into the microcapsule wall or into a layer continuous with the microcapsule 114.
4. A layer of developer material 120 is interposed between the layer of microcapsules 114 and support 112. The developing material 120 reacts with the color forming material to produce a colored image when the microcapsules are ruptured.

Exposure of the imaging sheet 110 is shown in FIG. 1B, where a source of radiant energy 122 is positioned on the surface of the source sheet 110 with a mask 124 between it and the imaging sheet 110. glA-1C In the illustrated example, support 1
12 is made transparent and the photosensitive material within the microcapsules 114 is a positive working radiation curable material. That is, exposure to actinic radiation increases the viscosity of the substance.

The radiation in the exposed region 126 polymerizes the radiation-curable composition and the internal phase 116 of the microcapsules 114, gelling, solidifying, and otherwise fixing the color-forming material so that it does not react with the developer material. For ease of illustration, the internal phase 116' of exposed chain acid 126 is shown as a solid;
The internal phase 116, on the other hand, remains liquid within the unexposed areas 128.

At least one
An unexposed imaging sheet 110 according to a preferred embodiment of the invention is processed by directing the imaging sheet into a nip formed between a pair of vinyl rolls, the pairs of which are positioned with their axes at an oblique angle to each other. Ru. As the imaging sheet 110 passes through the nip between the pair of vinyl rolls, the microcapsules 114 are encased in a rupturable or ruptured material so that the color forming material associated with the microcapsules can react with the developer material 120.

2-4 illustrate a preferred pressure development apparatus for developing an imaging sheet according to the present invention. The upper roll 200 of the pair of pinch rolls has a needle bearing 2
It is rotatably attached to a pair of housing-shaped side support members 204 provided on the base 206 via 02Y. The needle bearing 208 and the neck of the lower roll 210 of the pair of pinch rolls engage a guide wedge 204 mounted in a groove in the side support member 204 to allow the lower roll 210 to slide vertically within the side support member 204. supported by mated thrust bearings. The lower roll 210 is placed at an oblique angle with respect to the upper roll 200, as shown in FIG.

The support roll 216 is attached to the lower roll 21 so that it can move vertically.
Guided in the same way as the support of 0 (supported by the rust 220 via the needle bearing 21B. Support roll 21
6 is placed in a crossed position relative to the lower roll 210. The flat spring 222 is a guide wedge 2 that supports the support roll 216.
20. The flat spring 222 is pressed by the pressure bolt 224 through a spring shoe 226' which adjusts the thrust force to match the desired pressure by controlling the pressure port 224. .

As mentioned above, the guide wedge 220 is connected to the support roll 210.
is pressed against upper roll 200 by flat spring 222 to create a nip therebetween. Upper roll 2
Compensation for deflection or bending of the lower roll 210 resulting from the imaging sheet 110 passing through the nip between the roll 210 and the lower roll 210 is ensured by placing the support roll 216 at an oblique angle to the lower roll 210. In this example, the bevel of support roll 216 is shown as being opposed to the bevel of lower roll 210 relative to upper roll 200. The oblique angle of support roll 216 with respect to upper roll 200 is indicated by angle β in FIG.

The oblique angle α is the support roll 21 in the conventional six-roll system.
The oblique angle with respect to the pinch rolls 210 and 200 of No. 6 is relatively small. This is effective because it facilitates the support mechanism for the support roll 216.

In conventional parallel pinch rolls, the pressure applied to the imaging sheet is generally perpendicular to the plane of the paper. However, in accordance with a preferred embodiment of the present invention, the upper roll of pinch rolls 200. ! :, the lower rolls 210 are oblique to each other at a slight angle α.

The pressure is not only perpendicular to the paper (it is also applied in the axial direction to the roll).The pressure in the ims direction serves to rub the surface of the imaging sheet, thus helping to rupture the microcapsules on the surface of the imaging sheet. The corner must be selected within an appropriate range because if it is too large, the imaging sheet will wrinkle, and if it is too small, the pressure will not be uniform over the length of the double.

The bevel angle α is a diameter of 30 to 40 m for the upper roll 200, a diameter of 20 to 30 m for the lower roll 210, and 50 mrtr = 1100 for the support roll 216.
io'-i°30 for devices with a diameter of mtn.
′ must be within the range. Bevel angles greater than 1°30' will cause wrinkles in the imaging sheet, and bevel angles less than 10' will apply uneven forces to the nip of the pinch rolls.

When the bevel angle is selected within this range, suitable compressive and frictional forces are uniformly applied to the nip between the pinch rolls 200 and 210 to properly tear the microcapsules on the imaging sheet surface. The oblique angle of support roll 216 with respect to upper roll 200 must be limited within a reasonable range with respect to diameter and roll length.

According to the present invention, the pressure developing device includes a thrust bearing in addition to the needle bearing supporting the lower roll 210. When the drive shaft 228 of the upper roll 200 rotates in the direction of the circular arrow shown in FIG. 6, the lower roll 210 and support roll 216 rotate in the direction of their respective arrows shown in FIG. These rolls have six
It is affected by thrust in the direction of the horizontal arrow in the figure. With respect to upper roll 200 and support roll 216, the mechanical strength of the needle bearings 214 and 218 supporting the d-rolls, respectively, is sufficient to withstand the thrust forces due to their relatively large diameters. Lower roll 210
Regarding this, the needle bearing 208 is insufficient to withstand the thrust forces since the diameter of the lower roll 210 is quite small.

Therefore, it is desirable to provide means for receiving thrust at the end of the lower roll 210. Although FIG. 6 shows an example of an arrangement using both a needle bearing 208 and a thrust bearing 212, other conventional bearing means for receiving thrust may also be used.

Figures 5 and 6 show a first alternative embodiment of the invention in which only two pinch rolls are used. In this embodiment, the rolls 229 are provided at a suitable oblique angle to each other in the range of 10' to 1°30' and may be of the same diameter or of different diameters as shown. Although this embodiment of the invention can be successfully implemented for developing imaging sheets, it suffers from the deficiencies described above due to the two angled roll apparatus.

FIG. 7 shows a second alternative embodiment of the invention in which only two pinch rolls are used. However, in this example, the fifth
As shown in the enlarged figure, the pinch roll 250 is 9
The force is reflected to both ends of the roll and the middle cylinder roll 2
30 to compensate for bending of the rolls when forming the nip. In this embodiment, when the medium and high rolls 230 are pressed into engagement with each other to form a nip in the same manner as described above with respect to the embodiment of the invention shown in FIGS. The pressure applied at both ends creates a uniform bursting force over the entire length of the big.

Having described the preferred embodiment of the invention,
Modifications and alterations may be made without departing from the scope of the claims.

[Brief explanation of drawings]

1A to 1C show examples of imaging sheets developed according to the present invention, FIG. 2 is a plan view of a preferred apparatus for carrying out the present invention, and FIG. Figure 4 is a sectional view taken along line 4-4 in Figure 6;
The figure shows a first alternative embodiment of the present invention using two oblique rolls, FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, and FIG. 7 shows a middle-height roll. FIG. 3 is a diagram showing a second alternative embodiment of the present invention.

Claims (1)

[Claims] 1. Imagewise exposing an imaging sheet made of a support having a layer of photosensitive microcapsules on its surface, positioning a first and second roll to form a nip therebetween; 1st and 2nd
An imaging method comprising passing a roll of water through a nip formed between 10' and 1°30'. 2. The imaging method according to claim 1, wherein the first and second rolls are rotated by driving the first roll while driving the second roll in surface contact with the first roll. 3. An imaging sheet made of a support having a layer of photosensitive microcapsules on its surface is imagewise exposed, and the first and second medium/high rolls are positioned to form a nip between them. rotating medium and high rolls by pressing them together to create a uniform bursting force over the length of the nip;
An imaging method consisting of passing an imaging sheet through a nip between rolls. 4. The step of rotating the first and second medium-high rolls consists of driving the first medium-high roll while driving the second medium-high roll in contact with the first medium-high roll. Imaging method described in section. 5. The imaging method according to claim 1, wherein the first and second rolls have different diameters. 6. The imaging method according to claim 5, further comprising the step of making the third roll oblique with respect to the second roll.