JPH0445962A - Photoprinter - 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 [Industrial Field of Application 1] The present invention relates to a printing method using an optical printing press that performs printing by selectively irradiating light in accordance with a printing signal.

[Prior Art 1] A conventional optical printing press simply uses a transfer body regenerating means to irradiate the transfer body with light to erase a printed latent image formed on the surface of the transfer body.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, since the light emitted from the transfer body regenerating means that irradiates onto the transfer body leaks, the surface of the regenerated transfer body does not respond to the print signal. There is a technical problem in that stray light enters the newly written area, causing unnecessary exposure and causing printing defects such as a decrease in printing contrast.

Therefore, the present invention solves these technical problems,
The purpose is to provide a printing machine that can quickly perform printing without printing defects.

[Means for Solving the Problems 1] The printing machine of the present invention has a small number of transfer members (one or more transfer members, an optical scanning member for selectively irradiating the transfer member with light in accordance with a printing signal, and at least one I). :J, in an optical printing machine mainly composed of a transfer body reproducing means using the above-mentioned optical interpolation unit and a light shielding member for blocking light, the surface of the transfer body irradiated by at least the optical scanning body The light shielding plate is characterized in that unnecessary light is blocked for one part by the light shielding plate.

[Function] According to the above configuration of the present invention, by blocking stray light with the light shielding plate, exposure of the transfer member by unnecessary light can be prevented when performing optical writing on the transfer member. Therefore, it is possible to perform only optical writing according to the print signal, and to perform good printing.

[Embodiment] FIG. 1 is a main configuration diagram showing an embodiment of the present invention. FIG. 2 is a partial sectional view of the main part of FIG. 1 for explaining the present invention in detail. First, the operation of the main components related to the present invention will be explained using FIGS. 1 and 2.

The light beam 4 taken out from the laser generator 1, moderately modulated by a printing signal, is shaped by the collimating lens group 2, and while being focused, is scanned onto the photosensitive drum 6 rotating in the direction A by the rotating polygon i*3. I did it. The photosensitive drum 6 is a photosensitive member in which when the surface thereof is irradiated with light of a predetermined wavelength, the wettability with respect to the ink 7 differs greatly between the irradiated area and the non-irradiated area due to changes in the molecular structure and the like. Next, the photosensitive drum 6 is irradiated with the light beam 4 in accordance with the print signal.
A printed latent image 2 that has good wettability with the ink 7 is formed on the surface of the photosensitive drum 6 using an ink roller 9 installed in the developing device 8. The ink 7 was transferred and pressure transfer was carried out using a transfer roller 11 on paper as a printing medium. After printing, use cleaning buff 1 to remove residual ink and adhering dust on the photosensitive drum s.
3, and the surface of the photosensitive drum 6 was returned to the state before being irradiated with the light beam 4 by providing a reflecting plate 15 or by irradiating the surface of the photosensitive drum 6 with the light beam 14. At this time, when the light shielding plate 20 is installed between the reset lamp 15 and the reflection plate 14 and the light beam 4 as shown in the figure, the stray light 21 leaking from the reset lamp 15 is blocked and the light beam irradiation area is 22, the newly formed printed latent image 12, etc., were not irradiated, and high quality printing was stably obtained. Next, the operation of the present invention will be explained using FIGS. 3(a) to 3(b). Before the printing operation, the cleaning buff 13 was used to remove residual ink and attached dust from the surface of the photosensitive drum 6 while rotating the photosensitive drum 6 as a transfer body. At this time, the paper 10 to be printed is transferred to the transfer roller 11
Either they were loosened and moved away from the photosensitive drum 6, or they were placed on standby at a different position. Furthermore, during this time, the reset lamp 15
When the light was turned on, the surface of the photosensitive drum 6 could be stabilized even better. At this time, it would be more effective if the reset lamp 15 side of the light shielding plate 20 was processed to have a high reflectance, such as a mirror surface. Further, the ink roller 9, which is an ink applying body, is moved in the moving direction B, and while it is brought into contact with the ink mixing roller 17 without contacting with the photosensitive drum 6, the ink roller 9 is applied with 0.01 k.
By applying pressure between g/cm2 and 100 kg/cm2 and rotating, a fresh and very uniform ink layer is formed on the surface of the ink roller 9, which is very stable and good for the next printing process. A good print was obtained. Further, the ink 7 may be made to have a uniform and stable composition by stirring the ink 7 in the developing device 8 with the material in the ink tank 19 by rotating the ink outlet port 18 in forward and reverse directions. Further, although not shown in the drawings, in the process described in item 1, an appropriate ink scraping plate may be installed to adjust the thickness of the ink layer formed on the surface of the ink roller 9. Next, the same figure (b)
When the photosensitive drum 6 was irradiated with a light beam 4 modulated with an appropriate printing signal as shown in FIG. 1, and printing was performed as described above, very stable and good printing was obtained. Finally, in the same way as explained using FIG. 3(a), as shown in FIG.
As shown in C), when the surface of the photosensitive drum 6 and the ink roller 9 was stabilized and printing was completed, very stable, uniform and good printing was obtained in the next printing. In this case, when the optical printing press of the present invention was stopped and stored, measures were taken to prevent the ink roller 9 from coming into contact with the photosensitive drum 6, and appropriate shielding was performed to prevent ink evaporation. Furthermore, when the transfer roller 11 and the cleaning buff] 3 were stored in a stopped state and separated from the photosensitive drum 6, even more stable printing was possible when printing was started. In the present invention, when the light beam 4 irradiation side of the light shielding plate 20 is processed to reduce light reflection by making it a black fine-grained surface, etc., the light reflected from the photosensitive drum 6 surface etc. of the light beam 4 is exposed again. Good results with higher printing quality were obtained without any re-reflection of the irradiation onto the surface of the drum 6. Further, in the present invention, the light shielding plate 20 is made separately, but even if the shape of the reflecting plate 14 is made longer on the light beam 4 side and integrated with the reflecting plate 14, the light shielding plate 20 becomes more compact. The same effect was obtained. In addition, cleaning buff 13
The backlighting plate 20 may be installed to surround the light beam irradiation section 22, or a cover with a partition installed to prevent the stray light 21 of the reset lamp 15 from entering the light beam irradiation section 22 may be installed over the entire area or the area where you do not want external light to be irradiated. I was able to obtain very stable printing by installing it so that it covered each section as needed. In this case, better results were obtained by subjecting the inside of the cover to ashless treatment or light absorption treatment as required.

Here, an example of specific materials and devices used in the present invention will be explained. The laser generator 1 used a nitrogen laser, and the photosensitive drum 6 was an aluminum cylinder coated with a polymeric material containing an azobenzene polymer as a main component to a thickness of 1 to 500 μm. Ink 7 contains at least 0.3 water
The main component is a dye or pigment dissolved or dispersed in a polar solvent containing 0.1% or more.

The rollers in the developing machine 8 have fine-grained surfaces, undergo hydrophilic treatment such as plasma processing, or are provided with various grooves to adjust their wettability and retention characteristics with the ink 7. Adjusted printing characteristics.

The cleaning buff 13 cleans the surface of the photosensitive drum 6 while moving, but when printing the same pattern or when there is only a small amount of residual ink, each non-cleaning buff 13 is not brought into contact with the photosensitive drum 6 for a certain period of time. It was possible to control the consumption of the cleaning buff 13 by printing or cleaning by intermittently contacting it. When performing the same printing as described above, the reset lamp 15 was not turned on, or the surface of the photosensitive drum 6 was shielded from light using a shack or the like (not shown in the figure). A low-pressure mercury lamp was used as the reset lamp 15. In the optical printing press of the present invention, better and more stable printing was obtained when the cleaning buff 13 was impregnated with a cleaning liquid containing a surfactant or the like.

[Effects of the Invention] As described above, in the optical printing press of the present invention, the light from the transfer body regenerating means that brings the surface of the transfer body into a state before the formation of a printed latent image leaks and a new printed latent image is formed. Not only is it possible to print stably for a long time from the beginning of printing by preventing stray light from entering the area where the printer is located, but also by covering other areas, it blocks not only the above-mentioned light but also light coming from outside. This also has the effect of enabling more stable, high-contrast, high-quality printing. Furthermore, since it is possible to prevent the reflected light of the light beam forming the printing latent image from being irradiated onto other unnecessary parts, there is also the effect that higher quality printing can be obtained.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are main configuration diagrams each showing an embodiment of the present invention. The third section is a schematic diagram of the main configuration showing the operation of the embodiment of the present invention.・Rotating polygon mirror photosensitive drum ・Reflector reset lamp ・Shading plate 21 ・Stray light ・Light beam irradiation part and above

Claims (1)

[Claims] In an optical printing machine mainly composed of a transfer body, a light scanning body that selectively irradiates the transfer body with light according to a printing signal, and a transfer body reproducing means using light irradiation, at least the optical scanning body An optical printing machine characterized in that a light shielding plate is provided to block unnecessary light from the surface portion of the transfer body that is irradiated.