JPH02234150A - Optical system device for copying machine - 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 (Al Industrial Field of Application) The present invention relates to an optical system device for a copying machine that guides the light of an original image to an exposure position via a plurality of mirrors, and in particular, it relates to an optical system device for a copying machine that guides light from an original image to an exposure position through a plurality of mirrors, and in particular to The present invention relates to an optical system for a full-color copying machine using photosensitive materials having different photosensitive characteristics.

Yama》Conventional technology An image forming method using a media sheet coated with photocurable microcapsules containing an image forming agent such as a colorless dye, and an image receiving sheet coated with a developer that causes a color reaction with the image forming agent. has been proposed (Unexamined Japanese Patent Publication No. 5
8-8 87 3 9, etc.). In this image forming method, an original image is exposed on a media sheet at an exposure position, and a selectively cured image is formed by curing microcapsules that receive the light. The media sheet on which this selectively cured image has been formed is overlapped with an image receiving sheet and pressed.
The uncured microcapsules are destroyed and the image forming agent contained therein is leaked onto the image receiving sheet. An image is obtained on the image-receiving sheet by a coloring reaction between the leaked image forming agent and the developer.

In addition, Electronic Imaging (Mo
rgan-Granpia Publishing Ca
mpany 1984-Oct. ) inside “Photoc”
apsule Process for Hard C
In the opy output, each of the three subtractive primary color imaging agents is encapsulated in microcapsules that are sensitive to the light of the additive three primary colors that are complementary to that color, and these three types of microcapsules are An imaging method is disclosed in which full color images are obtained by uniformly dispersing and coating capsules onto a media sheet.

In this image forming method, when the light of the original image is irradiated onto the media sheet, the microcapsules containing each of the three primary colors in a subtractive color mixture are selectively hardened according to the color of the light, and together with the image receiving sheet. After completing the pressure process, a full-color image is reproduced on the image-receiving sheet (
C) Problems to be Solved by the Invention In a media sheet coated with the above three types of microcapsules, the spectral intensity of the microcapsules containing image promoting agents of each color is not uniform, and it is difficult to easily control lighting. Taking this into consideration, the spectral radiation characteristics of halogen lamps commonly used as light sources are also not uniform. On the other hand, in order to improve the color reproducibility of media sheets, it is necessary to ensure that the product of the amount of exposure light and the sensitivity of the media sheet (the amount of light received) is approximately It must be kept constant. However, as mentioned above, due to the non-uniformity of spectral intensity and spectral radiation characteristics, the amount of light received in each wavelength range is not constant. It is necessary to cut out some of the wavelengths of light. For this reason, effective use of light cannot be achieved, and combined with the low absolute sensitivity of the media sheet, there is a problem in that a light source with large power consumption is required. Another problem was that a filter had to be installed in the optical path to cut out light of specific wavelengths. An object of the present invention is to appropriately set the spectral reflectance of the mirrors constituting the exposure optical path based on the light intensity of the light source and the sensitivity of the media sheet in each wavelength range. To provide an optical system device for a copying machine, which can perform exposure with a light amount according to the sensitivity of one person, eliminate the need to cut a part of light from a light source, and reduce the light amount of a light source. It is in.

(d) Means for Solving the Problems The optical system for a copying machine of the present invention is a copying machine optical system that includes a plurality of mirrors in an optical path from a light source position to an exposure position of a photosensitive material. For each wavelength range of the three primary colors of the mixture, the spectral reflectance of each of the plurality of mirrors is set so that the product of the light intensity of the light source, the reflectance of the plurality of mirrors, and the sensitivity of the photosensitive material is approximately constant. It is characterized by what it did.

(e) Effect In the present invention, the product of the exposure light amount and the sensitivity of the photosensitive material is approximately constant for each wavelength range of the three primary colors of the subtractive color mixture. Therefore, there is no need to use a filter to cut off the light of a specific wavelength from the light source, and the light from the light source is effectively irradiated onto the photosensitive material.

(f) Example 1st rf! J is a schematic front cross-sectional view showing the configuration of a copying machine to which an optical system device according to an embodiment of the present invention is applied.

On the top surface of the copying machine main body 11 is a document table 8 made of hard transparent glass.
is provided. A light source 2,
An optical system device 1 consisting of mirrors 3 to 6 and a lens 7 is provided. In the optical system device 1, a light source 2 and mirrors 3 to 5 move back and forth on the lower surface of the document table 8 to scan an image of a document placed on the document table 8. A pair of pressure rollers 14a and 14b are pivotally supported in the center of the interior of the copying machine main body 11, and constitute a pressure position 15. A media sheet 12 wound and stored in a roll is placed at an exposure position 13.
It is guided to pressurizing position 15 via . A paper cassette 18 containing an image receiving sheet 19 is attached to one side of the copying machine main body 11. Image reception sheet 1
9 is fed to the timing roller 22 one by one by the rotation of the paper feed roller 20. The timing roller 22 rotates at a predetermined timing and guides the image receiving sheet 19 to a pressurizing position 215.

During copying work in the copying machine configured as described above, the optical system device 1 reciprocates on the lower surface of the document table 8, and the light source 2
The reflected light from the original is distributed to the exposure position 13 via mirrors 3 to 6 and lens 7 as indicated by arrows in the figure. The microcapsules coated on the surface of the media sheet 12 are exposed and cured at the exposure position 13, and a selectively cured image is formed on the media sheet 2. The image receiving sheet 19 is guided to the pressurizing position 15 together with the media sheet 12 on which the selectively cured image is formed. When the media sheet 12 is pressurized at the pressurizing position 15, the uncured microcapsules are destroyed and the image forming agent contained therein leaks out. The image-forming agent leaked from the uncured microcapsules causes a coloring reaction with the developer of the image-receiving sheet, and a copied image is formed on the image-receiving sheet 19.

The surface of the image receiving sheet 19 is coated with a thermoplastic resin together with a developer, and this thermoplastic resin is heated by the glossing device 16 and melts, giving gloss to the image on the image receiving sheet 19. ．． The image receiving sheet 19 that has passed through the glossing device 16 is stored in a tray 21. On the other hand, pressure position 15
The media sheet that has passed through is separated from the image-receiving sheet and guided to the paper discharge section 17.

The microcapsules containing the yellow, magenta, and cyan color image forming agents coated on the media sheet 12 used in the above-mentioned copying machine are each tertiary.
It has the spectral sensitivity characteristics shown in the figure. As shown in the figure, the photosensitivity of each color of yellow, magenta, and cyan is approximately 3:2:1. Therefore, the light intensity ratio of blue, green, and red light, which are complementary colors, is 1 = 2.
:3, the amount of light received in the visible light range is substantially smoothed, and good color reproducibility can be obtained. Further, in the copying machine 11, the light source 2 is constituted by a halogen lamp, and has the spectral radiation characteristics shown in FIG. As shown in the figure, the amount of blue light, green light, and red light emitted from the light source 2 is approximately 1:2:3. Therefore, light a2
The mirrors 3 to 6 that distribute the light to the exposure position 13 preferably have smooth spectral reflectance characteristics in the visible light range.

However, in reality, there is no mirror that has smooth spectral reflectance characteristics in the visible light range, and when all mirrors 3 to 6 have the spectral reflectance characteristics shown by the dashed-dotted line in FIG. The overall spectral reflectance of mirrors 3 to 6 is as shown by the solid line in the figure. For this reason, blue light and red light are insufficient compared to green light, so in order to obtain good color reproducibility, it is necessary to cut out part of the green light using a filter. In reality, since there is no filter that can cut only part of the green light, part of the blue light and part of the red light are also cut at the same time. The amount of light irradiated to the area is extremely small.

Therefore, in this embodiment, as shown in FIG.
Two mirrors out of 6 had the spectral reflectance characteristics shown by the dashed-dotted line in the figure, and the remaining two mirrors had the spectral reflectance characteristics shown by the dashed-double line in the figure. With this configuration, the spectral reflectance characteristics of the mirrors 3 to 6 as a whole become substantially smooth in the visible light range, as shown by the solid line in the figure.

Therefore, there is no need to cut out part of the light of a specific wavelength among the light from the light source 2, and much of the light from the light source 2 can be distributed to the exposure position 13.

The above is clear from the following comparative experiment.

That is, when copying is performed using an 800 W halogen lamp as the light source 2 and an optical system device having the mirror of this embodiment shown in FIG. 2, the scanning speed in the optical system device is 6.5 mm/sec. An image with proper exposure was obtained. On the other hand, in the optical system equipped with the mirror shown in FIG. 5, proper exposure was obtained at a scanning speed of 8.2 flI/sec. As described above, in this embodiment, when the same light source is used, it is possible to improve the scanning speed by about 26%. In other words, if the speed is the same, the amount of light from the light source can be reduced by about 20%, which has the advantage of reducing power consumption. Further, when a mirror having the characteristics shown in FIG. 5 is used, a magenta color correction filter with an exposure density of 0.3 must be used, but in this embodiment, it is not necessary to provide such a filter.

(Effect of the Phantom Invention According to this invention, it is possible to obtain good color reproducibility without using a filter, so the light from the light source can be effectively distributed to the exposure position, reducing power consumption or improving scanning speed. It is possible to aim for

[Brief explanation of drawings]

FIG. 1 is a schematic front cross-sectional view showing the configuration of a copying machine to which an optical system device according to an embodiment of the present invention is applied, and FIG. 2 shows the spectral reflectance of a mirror used in the optical system device of the same copier. 3 is a diagram showing the spectral sensitivity of a media sheet (photosensitive material) used in the copying machine, and FIG. 4 is a diagram showing the spectral radiation characteristics of the light source of the copying machine. Furthermore, FIG. 5 is a diagram showing the spectral reflectance characteristics of a mirror included in a conventional optical system device. 1 - optical system device, 2 - light source, 3 - 6 - mirror 11 - copying machine, 2 - media sheet (photosensitive material) 3 - exposure position.

Claims (1)

[Claims] (1) In an optical system device for a copying machine that includes a plurality of mirrors in the optical path from the light source position to the exposure position of the photosensitive material, the light intensity of the light source and the number of mirrors are determined for each wavelength range of the three primary colors of subtractive color mixture. An optical system device for a copying machine, characterized in that the spectral reflectance of each of the plurality of mirrors is set so that the product of the reflectance of the light-sensitive material and the sensitivity of the photosensitive material is substantially constant.