JPH01197737A - Reflection type projecting device - Google Patents

Abstract

PURPOSE:To eliminate unevenness of illuminance by arranging a first dichroic mirror between a light source and first and second image media, and a second dichroic mirror between first and third image media and exposuring by means of overlap. CONSTITUTION:Projection light emitted from the light source 5 passes through a condenser lens 6, is reflected by a half mirror 8 through a cold filter 7, and is made incident on the dichroic mirror 12. After that, it is transmitted or reflected by the mirror, and green light is projected on a light bulb 1 and red light on a light bulb 2. The reflected light from these light bulbs are reflected or transmitted by the mirror 12, two rays of colored light are synthesized, and exposed on a photosensitive body 10 through a projecting lens 9. Subsequently, the dichroic mirror 13 is made effective in a mirror changeover part. After this, by the same process as mentioned above, optical space pattern corresponding to red color and blue color which are formed on the light bulb 2 and 3 are overlapped and synthesized on the same photosensitive body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a projection exposure apparatus that projects optical spatial patterns on a plurality of image media onto the same photoreceptor or the like.

[Summary of the invention]

The present invention provides that when simultaneous multicolor exposure using a dichroic prism is adopted in a projection exposure apparatus, uneven illuminance may occur on the surface of the photoreceptor to be exposed, and the processing accuracy and assembly accuracy of the prism may be high. Therefore, multiple relatively inexpensive dichroic mirrors that transmit or reflect colored light in a certain wavelength range are used, placed between the light source and the image medium, and these mirrors are switched according to the sensitivity of the photoreceptor. By setting the intensity and number of exposures of the colored light to be projected and combining three or more optical spatial patterns onto the same photoreceptor, uneven illuminance on the photoreceptor can be reduced using relatively hourglass optical components. This makes it possible to irradiate light energy that matches the sensitivity of the photoreceptor and simultaneously expose multiple colors in a short time.

(Prior Art) Conventionally, a projection exposure apparatus has been proposed that uses a plurality of image media to superimpose images of different color lights on the same photoreceptor to obtain a color image.

FIG. 2 is a block diagram showing an example of a conventionally proposed device. In the figure, reference numerals 1, 2, and 3 are image media such as reflective liquid crystal light valves having optical spatial patterns, and these are attached to the projection lens 9 so as to be at equivalent positions. A dichroic prism 4 is installed at the center of this liquid crystal light valve group. In this dichroic prism 4, as shown in FIG. 3, for example, reflection filters for the green wavelength range and the blue wavelength range are formed on the reflecting surfaces 41 and 42, respectively.

The projection optical system surrounded by a broken line in FIG. 2 is composed of a light source 5, a condenser lens 6, a cold filter 7, a half mirror 8, and a projection lens 9 using a halogen lamp.

The projection exposure apparatus configured as described above operates as follows.

When the projection light is emitted from the light a5, the condenser lens 6
The light beam passes through the , is converted into a slightly convergent light beam, passes through a cold filter 7, is reflected by a half mirror 8, and enters a dichroic prism. This incident light is divided into each color component by being reflected or transmitted by the reflective surfaces 41 and 42, green light is sent to the image medium 1 such as a light valve, red light is sent to the image medium 2 such as light pulp, etc. Blue light is projected onto an image medium 3 such as a light valve. The reflected light from the image medium such as the light valve is reflected by the dichroic prism 4 or passes through the dichroic prism 4, and the three colored lights are combined and exposed onto the photoreceptor 10 through the projection lens 9.

In general, a halogen lamp has a light emission spectral characteristic as shown in FIG. 5, and a photoreceptor has a light sensitivity spectral characteristic as an example shown in FIG.

[Problem that the invention seeks to solve]

However, when using a dichroic prism as described above, in order to prevent the influence of the joint at the center of the prism from appearing on the projected image on the photoreceptor, it is necessary to increase the processing accuracy of each prism and assemble it at the same time. Accuracy also had to be improved, which led to higher costs.

In addition, in order to correct the emission spectral characteristics of the halogen lamp and the photosensitive spectral characteristics of the photoreceptor, a dichroic prism 4
Another problem was that a density filter had to be provided between the image medium 1, 2.3 and the image medium 1, 2.3.

Therefore, the purpose of the present invention is to solve these drawbacks of the conventional technology, and to obtain a projected image with little unevenness in illuminance using a relatively inexpensive method, and to enable exposure to match the sensitivity of the photoconductor without the need for a separate density filter. The object of the present invention is to obtain a projection exposure apparatus that can perform

[Means for solving problems]

In order to solve the above problems, the present invention uses two or more types of dichroic devices that transmit approximately the same wavelength range.
A mirror is movably supported, and among three or more image media, the other image media are placed in a position where they are overlapped by rotational movement, and the first image medium is placed at the center of the rotational movement. Dichroic ink mirrors that reflect light in a wavelength range corresponding to an image medium other than the image medium toward the image medium are sequentially switched and arranged to reduce uneven illuminance and achieve exposure that matches the spectral sensitivity of the photoreceptor. I made it possible to do this.

[Operation] With the above configuration, the first dichroic mirror is disposed between the light source and the first and second image media, thereby allowing the first image medium to emit light in the first wavelength range. A second image medium is illuminated with light in a second wavelength range, the respective images are overlapped and exposed on a photoreceptor, and then a second dichroic mirror is used as a light source. By disposing it between the first and third image media, the first image medium is illuminated with light in the first wavelength range, and the third image medium is illuminated with light in the third wavelength range. , by superimposing and exposing the respective images on the photoreceptor, the first image medium corresponding to the light in the first wavelength range where the spectral sensitivity of the photoreceptor is low is projected and exposed twice, and the other image medium is projected and exposed twice. 2. The third image medium can be projected exposed only once.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
The figure is a block diagram showing one embodiment of the present invention, and the same symbols are used for the same parts and corresponding parts as in FIG. 2. A halogen lamp is used as the light source 5, and its spectral characteristics are such that the specific radiation intensity is greater in the longer wavelength range, as shown in FIG.

As an example of the photosensitive spectral characteristics of the photoreceptor, as shown in FIG. 6, the sensitivity is highest in the green wavelength range, followed by the highest sensitivity in the blue wavelength range. Furthermore, the photosensitivity in the red wavelength range is extremely low. Therefore, in order to make the reaction to each color light on the photoreceptor uniform, medium color (R), green (G)
It is necessary to set the irradiation energy of each color light of blue (B) to #7:1:2...ill. The dichroic mirrors 12 and 13 have a switching mechanism as shown in Figure 7, and the four frames 14
The structure is such that two dichroic mirrors 12, 13 sandwiched between three slide mirrors 15, 16, and 17 can slide together in the a-b direction. In addition, dichroic ink mirror 12.13
are orthogonal at slide play number 6. The dichroic mirror 12 reflects light in the green range and transmits light in the red range. If the reflectance of light in the green region is set to be approximately 35% of the transmittance of light in the red region, the light intensity on the photoreceptor surface will be R: G = 0.90 F (0.74X0. 35) #
7:2...(2) The dichroic mirror 13 is one that reflects light in the blue range and transmits light in the red range.

If the transmittance of light in the red region and the reflectance of light in the blue region are made almost equal, the light intensity on the photoreceptor surface will be R: B = 0.90? 0.52 h7:4 (3).

The operation of the apparatus configured as described above is as follows.

First, in the dichroic mirror switching section shown in Fig. 7, slide the entire dichroic mirror in direction a, and
Enable mirror 12. When the projection light is emitted from the light source 5 in this state, it passes through the condenser lens 6, is converted into a slightly convergent light beam, passes through the cold filter 7, is reflected by the half mirror 8, and enters the dichroic mirror 12. . This incident light is then transmitted or reflected by this dichroic mirror 12, and green light is projected onto the light pulp 1 and red light is projected onto the light pulp 2. The reflected light from these light pulps is reflected or transmitted by a dichroic mirror 12, and the two colored lights are combined and exposed onto a photoreceptor 10 through a projection lens 9. Once the photoreceptor 10 has been irradiated with the required light energy, the dichroic mirror switching section shown in FIG. 7 slides the entire device in the direction b to enable the dichroic mirror 13. Thereafter, in the same process as described above, the optical spatial patterns corresponding to red and blue formed on light pulps 2 and 3 are superimposed and synthesized on the same photoreceptor as described above. The projection exposure ends when the photoreceptor is irradiated with the required light energy. That is, the light pulps 1 and 3 are projected and exposed only once, and the light pulps 2 and 2, on which an optical spatial pattern corresponding to red light with low photosensitivity is formed, are exposed once.
Projection exposure is performed twice.

Here, if the projection time when using the dichroic mirror 12 is equal to the projection time when using the dichroic mirror 13, the total energy irradiated to the photoreceptor is calculated by the formula f21. +31, for each color light, R:G:R=14:”2:4 =7:1:2 (4), and the irradiation energy ratio is shown in equation [11], and the amount of light on the photoreceptor is The reaction to each color of light can be made uniform.

Although liquid crystal light pulp was used as the image medium in this embodiment, this does not limit the image medium that can be used in the present invention, and it is of course possible to use image media with similar functions.

Further, the configurations of the light source, the illumination optical system, the projection optical system, and the switching mechanism of the dichroic mirror are not limited to the present embodiment.

〔Effect of the invention〕

As explained above, this invention uses a simple optical component that uses dichroic mirrors to separate and combine color light, and enables projection exposure with less uneven illuminance and light that matches the spectral sensitivity characteristics of the photoreceptor. It has the effect of making it possible to irradiate energy and also make it possible to expose multiple colors in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention, FIG. 2 is a schematic explanatory diagram showing an example of a conventional projection exposure apparatus, FIG. 3 is a plan view showing the vicinity of a dichroic prism, and FIG. A plan view showing the area around the dichroic mirror, Fig. 5 is a characteristic diagram showing the emission spectral characteristics of the halogen lamp, Fig. 6 is a characteristic diagram showing the photosensitive spectral characteristics of the photoreceptor, and Fig. 7 is the implementation of the dichroic mirror switching section. It is a perspective view showing an example. l... Light pulp 4... Dichroic prism 5... Light source 6... Condenser lens 7... Cold filter 8... Half mirror 9... Projection lens lO... Photoreceptor 12...Dichroic mirror Applicant: Seiko Electronics Co., Ltd. Example of temporary exposure placement ε Ho 1 I Already 8 Embossed Figure 2 Figure 9', (70・r・So 77°゛1゛」mu Shubo's + side area Figure 3 Ro====22 February ~ February 1 valve (G) 5”f 70
Lee, Seo 7, Miller, ■ Planned figure of 4, Figure 141, Figure 5

Claims (1)

[Claims] first, second, and third image media having a light source and an optical spatial pattern; a lens system that guides the light energy of the light source to the image medium; and a lens system that directs the optical spatial pattern on the image medium to an imaging plane. one or more projection lens systems that form an image and guide the light energy reflected or transmitted by the image medium to the imaging surface; a projection lens system that transmits light in a first wavelength range and that transmits light in a second wavelength range; A first dichroic mirror that reflects light in the first wavelength range and a third dichroic mirror that transmits light in the first wavelength range.
and a second dichroic mirror that reflects the light, the first dichroic mirror illuminates the first image medium with light in the first wavelength range, and the first dichroic mirror illuminates the first image medium with light in the first wavelength range. The second image medium is illuminated with light in the second wavelength range, and their respective images are superimposed and exposed on the photoreceptor, and the second dichroic mirror illuminates the second image medium with light in the first wavelength range. A projection exposure apparatus characterized by illuminating with light in a wavelength range, illuminating the third image medium with light in the third wavelength range, and superimposing and exposing the respective images on the photoreceptor.