JPS63208032A - Color printer - Google Patents

Abstract

PURPOSE:To permit adjustment of an exposing wavelength to an optimum wavelength so that good color formation is attained without changing a wavelength selection filter by changing the inclination of an interference filter provided at the mid-point of an optical path with the optical axis. CONSTITUTION:The interference filter 1 is a filter which makes use of the interference of the light between thin films. Said filter is formed by laminating thin films of metals or nonmetals by vapor deposition, etc., on a transparent substrate. The filters having various transmission characteristics can be formed by changing the film thicknesses of the respective layers or the number of the layers. The transmission wavelength can be shifted by about 25mm to a short wavelength side with not so much deterioration in spectral characteristics up to about 20 deg. if the interference filter 1 is inclined with respect to the optical axis. The adjustment of the wavelength to the optimum exposing wavelength is thereby permitted without exchanging the filter even when the wavelength- sensitivity characteristics of an image sheet G vary with the difference in production lots, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color printer that prints color images on paper.

[1 Summary of the Invention] The present invention provides a color printer that prints a color image by applying light of a specific wavelength onto an image sheet coated with photosensitive microcapsules, and in which an interference filter (around the By changing the viewing angle, the transmitted wavelength can be changed and color development can be controlled.

[Conventional technology]

Conventionally, thermal transfer methods, inkjet methods, and electrophotographic methods have been put into practical use as devices for printing color images, but all of them have problems such as easy color shift, slow printing speed, and complicated and expensive mechanisms. They each have

In order to solve these problems in Japanese Patent Application No. 61-135438, the present applicant has developed a microorganism that encapsulates coloring precursors of different colors and a sensitive material that immobilizes the coloring precursors in response to light of a specific wavelength. A monochrome image created by electrophotography or the like in accordance with color-separated image signals is projected onto an image sheet coated with capsules using light of a specific wavelength, and then the microcapsules in the image sheet are destroyed to develop color and print. proposed a color printer. .

[Problem that the invention seeks to solve]

In the device that Kideto proposed earlier, a white light source such as a xenon lamp or a halogen lamp is used as the light source, and the light from there is passed through a wavelength selection filter to select light at a wavelength sensitive to a specific capsule. . The image sheet is uniformly coated with three types of microcapsules containing color-forming precursors that develop the three primary colors of yellow, magenta, and cyan, each of which cures in response to light of a specific wavelength. Therefore, one type of capsule,
For example, in order to cure only yellow capsules, it is necessary to use a filter that transmits only wavelengths within a range that does not affect other capsules, and the same applies to magenta and cyan. However, the wavelength-sensitivity characteristics of image sheets vary slightly due to differences in manufacturing lofts, etc., and conventionally there has been a problem in that the filter must be replaced with a filter having an optimal transmission wavelength for each manufacturing lot.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and by changing the inclination of an interference filter with respect to the optical axis provided in the middle of the optical path from the white light source to the monochrome image, the wavelength-sensitivity characteristics of the image sheet can be improved. The structure is such that the exposure wavelength is adjusted according to the

[Effect]

As shown in FIG. 3, the three types of microcapsules coated on the image sheet are λ1. Each has sensitivity in a wavelength range centered at λ2°λ. Therefore, for example, in order to selectively cure only the capsules having a wavelength of 1.delta. with respect to light having a wavelength of .lambda., an interference filter having a transmission characteristic as shown by the solid line in FIG. 4 is used for exposure. Interference filters are filters that utilize light interference between thin films, and are made by laminating metal or non-metal thin films on a transparent substrate by vapor deposition, etc. By changing the thickness or number of layers of each layer, various transmission characteristics can be achieved. A filter with is created. Further, when the interference filter is tilted with respect to the optical axis, the spectral characteristics do not deteriorate much if the interference filter is tilted up to about 20 degrees, and the transmission wavelength can be shifted to the shorter wavelength side by about 25 mm. Therefore, even if the wavelength-sensitivity characteristics of the image sheet change due to differences in manufacturing lots, the exposure wavelength can be adjusted to the optimum exposure wavelength without replacing the filter.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
The figure is a sectional view of a device showing an embodiment of the present invention. Reference numeral G in the figure is an image sheet, and as shown in the cross-sectional view of the image sheet in FIG. 2(A), coloring precursors a1. a2. a3, and a different wavelength λ1 for each color precursor. λ2. A sensitive substance that immobilizes a coloring precursor by changing its viscosity etc. in response to light of λ.

Microcapsules B3 surrounded by a thin film C of gelatin or the like are uniformly coated on the surface of the sheet B, and have wavelength-sensitivity characteristics as shown in FIG. J is a developing sheet, and as shown in the cross-sectional view of the developing sheet in Figure 2 (0), a developer E that reacts with the coloring precursor al+aZ+a3 of the image sheet to form a color is applied to the surface of the sheet F. It consists of a coating. The image sheet G is placed on one roller llb of the developing device 11.
A light-receiving region K is formed between the guide roller 13 and the guide roller 13, with the microcapsule side facing the projection lens 7.

Reference numeral 9 indicates an image sheet supply reel, and IO indicates an image sheet take-up reel. The developer sheet J is supplied to the developer sheet supply reel 8.
The side of developer E facing the microcapsules is supplied between developing rollers lla and llb. Developing device 11
A heat roller 12 is provided on the downstream side of the developing sheet J to raise the temperature in order to fix the developing sheet J and make it glossy. 5 is an image plate, on the surface of which are formed three monochrome toner images created by an electrophotographic process according to color separation image signals corresponding to yellow, magenta, and cyan. 3 is a lamp that emits white light. Further, a reflecting mirror 4 is provided on the back side of the lamp 3. The light from the lamp 3 passes through the condenser lens 2a.

2b and interference filter 1, and half mirror 6.
, reflected by the image plate 5 and incident on the projection lens 7. Interference filter 1 is for yellow exposure,
Three types are provided, one for magenta exposure and one for cyan exposure, and are configured so that they are switched next and enter the optical path. Further, each of the interference filters 1 has a configuration in which the inclination angle with respect to the optical axis can be varied, and the inclination is adjusted so as to provide optimum transmission characteristics in accordance with the wavelength-sensitivity characteristics of the image sheet 5. That is, when exposing one type of capsule, the inclination of each interference filter 1 is adjusted so that only wavelengths to which the other two types of capsules are not sensitive are transmitted. A projection lens 7 projects the monochrome toner image formed on the image plate 5 onto the light-receiving area K of the image sheet G using light from a lamp via a filter.

The printing operation will be explained below. First, a toner image for yellow exposure on the image plate 5 is projected onto the image sheet G by light having a sensitive wavelength λ of the sensitive material of the yellow coloring microcapsules Δ. The projection wavelength is selected by switching a filter 1 provided in the middle of the optical path. In addition, in order to correct manufacturing variations in microcapsules on the image sheet,
Adjust the slope of filter 1. Microcapsules Δ are formed in the portion of the image sheet 5 that is hit by the light of wavelength λ1.

is cured and no color develops even during subsequent development, and a yellow latent image consisting of cured capsules and uncured capsules is formed on the image sheet G.

Next, the magenta exposure toner image is projected onto the image sheet G by light having the sensitive wavelength λ2 of the sensitive material b2 of the magenta coloring microcapsule A2, thereby creating a magenta latent image.

The same applies to cyan.

In the case of magenta and cyan, the inclination of the filter is also adjusted. By sequentially projecting the three projected images of yellow, magenta, and cyan onto the same position on the image sheet G, a color image is formed as a latent image on the image sheet G. be done. Thereafter, the image sheet G is sent to the developing device 11. The developing device 11 presses the image sheet G and the developing sheet J by sandwiching them between two rollers lla and llb. Among the microcapsules on the image sheet G, the microcapsules that are not sensitive to light and are not cured are destroyed by pressure, and the coloring precursors in the capsules are discharged onto the developing sheet J. The developing sheet J coming out of the developing device 11 is heated by the heat roller 12, and
Coloring precursor al+ a oozed out onto the developing sheet 1-J
The reaction between ffi+a3 and developer E rapidly progresses to produce a color corresponding to the image signal, and a color image is printed.

〔Effect of the invention〕

As explained above, according to the present invention, even if the wavelength-sensitivity characteristics of the image sheet change due to differences in manufacturing loft, the exposure wavelength can be adjusted to the optimum without replacing the wavelength selection filter, and good color development can be achieved. Obtainable.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing an embodiment of a color printer of the present invention, Figures 2 (a) and 3 (b) are cross-sectional views of an image sheet and a developing sheet, and Figure 3 is a wavelength-sensitivity diagram of the image sheet. FIG. 4 is an explanatory diagram showing the transmission characteristics of the interference filter. L...Interference filter 7...Projection lens 11...Developer G...Image sheet J...Developer sheet Applicant: Seiko Electronics Co., Ltd. Family map No. 1 (Drawing 1 of the sheet; round length, 3
figure

Claims (1)

[Claims] An image sheet coated with microcapsules enclosing color precursors of different colors and a sensitive substance that immobilizes the color precursors in response to light of a specific wavelength, a monochrome image created according to each color separation signal, and the monochrome image. In a color printer comprising a projection means for projecting the image onto the image sheet with light of a specific wavelength, and a means for destroying the microcapsules of the image sheet to generate a coloring substance, the inclination of an interference filter provided in the middle of the optical path is changed. A color printer characterized in that the color printer is configured to adjust color development by adjusting the color output.