JPS63271301A - Light source for optical shutter array - Google Patents

Abstract

PURPOSE:To enable supply of a sufficient quantity of light to an optical shutter array with high efficiency of light utilization by providing a diffusion pipe which reflects the light emitted from a lamp and reflecting mirror so as to constitute a luminous flux having nearly isotropy heading toward the adequate incident direction of the optical shutter array and a light guide. CONSTITUTION:The light from the halogen lamp 21 heads partly directly toward an IR cut filter 24 and partly to a dichroic mirror 22. The light heading to the mirror 22 is reflected on the inside surface and is advanced toward the filter 24 and the diffusion pipe 23 to constitute the luminous flux nearly parallel with the light heading to the filter 24 and the arranging direction of the LCS array 9. The light which is thereafter made into white light by being removed of IR rays enters the inside of the body 25 of the diffusion pipe 23, by which the quantity of the light is uniformly dispersed and the isotropy toward the adequate incident direction to the LCS array 9 is imparted on the light. This light is entered through a slit 27 into the light guide 8. The sufficient quantity of the light is thereby supplied to the optical shutter array with the high efficiency of light utilization.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a light exposure device used in an electrophotographic device, etc., which exposes a photoreceptor that has been uniformly banded and lightning-stripped in advance to form an electrostatic latent film. The present invention relates to a light source for an optical shutter array that illuminates a shutter array with light.

[Conventional technology]

The optical shutter array used as an exposure device has
There are specialized liquid crystal optical shutter arrays and magneto-optical shutter arrays. These structures are formed by arranging in the longitudinal direction a large number of minute liquid crystal shutters or magneto-optical shutters that can freely switch between blocking and transmitting light emitted from a light source toward a photoreceptor.

In order to operate the optical shutter array formed in this way and expose the photoreceptor well, it is necessary to make the light emitted from the light source to the optical stain/vine array uniform by 1 fe in the longitudinal direction of the optical shutter array and to make it uniform. It must be directional.

For this purpose, conventionally, a light source 1 for an optical shutter array is formed as shown in FIG.

However, in the conventional light source 1 for an optical shutter array, an aperture type fluorescent tube 2 is used as an example of a light emitter. This aperture-type fluorescent tube 2 has a length equal to or longer than the longitudinal direction (vertical direction of the paper in FIG. 4) of a liquid crystal light shutter array (hereinafter referred to as an LCS array) 9, which will be described later. The structure is composed of a cylindrical glass tube 3, a reflective film 4 formed inside the glass tube 3 except for the lower part, and a fluorescent material 5 formed inside the reflective film 4. J3, light is transmitted through the glass tube 3 from the reflective film 4 and the slit 6 of the fluorescent material 5 and is irradiated downward. Further, this aperture type fluorescent tube 2 is housed inside a casing 7 made of a light shielding member.

The casing 7 supports a light guide 8 made of glass or resin directly below the fluorescent tube 2 so as to face the slit 6 .

The LCS array 9 disposed below the light guide 8 includes glass plates 1 disposed at intervals in the vertical direction.
A sealing member 11 is interposed between 0Δ and 10B, and a liquid crystal 12 is sealed inside this sealing member 11, and both glass plates 10A are arranged.

10B is connected to transparent electrodes 13A and 13B. When a voltage is applied between the transparent electrodes 13A and 13B, the arrangement of molecules in a specific area of the liquid crystal 72 changes, making the liquid crystal 12 opaque and changing the light-shielding state. can do. Furthermore, polarizing plates 14A and 14B are provided on the upper surface of the glass plate 10A and the lower surface of the glass plate 10[3, respectively.

A self-focusing rod lens array 15 that is long in the same direction as the LCS array 9 is disposed below the LCS array 9, and the light that has passed through the LCS array 9 is transmitted through the self-focusing rod lens array 15. is imaged onto the photoreceptor 16 below the self-focusing rod lens array 15. The aperture-type fluorescent tube 2, light guide 8, LCS array 9, and self-focusing rod lens array 15 are separated by a predetermined spacing (not shown) by a spar (J), and are sealed in a sealing member (not shown).

According to the above-described configuration, by controlling the voltage to the transparent 7ri 13A, 13[3 of the LCS array 9, the liquid crystal 1
2 becomes partially and selectively opaque, so that the light emitted from the fluorescent tube 2 of the light source 1 for the optical shutter array into the LCS array 9 via the light guide 8 interacts with the transparent portion of the liquid crystal 12. The selected opaque portion is imaged onto the photoreceptor 16 by the self-focusing rod lens array 15.

Therefore, the photoreceptor 1 is uniformly charged in advance.
Of the charges on the photoreceptor 16, the charges on the portion imaged by the self-focusing rod lens array 15 are removed by exposure, and an electrostatic latent image is formed on the photoreceptor 16.

(Problems to be Solved by the Invention) However, in the conventional light source 1 for an optical shutter array, a fluorescent tube 2 is used as a light emitting body.
Since the amount of light m per area is small, there is a problem in that the photoreceptor 16 is underexposed.

Therefore, conventionally, as shown in FIG.
The light emitted from the DI mirror 18 is focused in one direction by the anti-DI mirror 18, and the focused light is input into a number of optical fibers 19, 19, each of which is focused at one end. The light guide 8 is passed through each optical fiber 19, 19... whose ends are arranged and connected in the longitudinal direction of the light guide 8.
Hey J! ! 7 I'm trying to hold back.

However, in the conventional example shown in Fig. 5, it is difficult to accurately connect a large number of optical fibers 19, 19, numbering into the hundreds, to the light guide 8, and the cost I is also high. there were.

The present invention has been made in view of these points, and it is possible to use a lamp with a large luminescence a as a light emitter, to have high light utilization efficiency, to supply sufficient light to the optical shutter array, and to have a structure. It is an object of the present invention to provide a light source for an optical shutter array that is simple, easy to manufacture, and low in cost.

[Means for solving problems]

The light shutter array light source of the present invention includes a lamp that generates light, and a light emitted from the lamp that illuminates the light shutter array arranged in the longitudinal direction. The anti-0 = J I, the above, the lamp and the reflection &
a diffuser tube that reflects the light emitted from the light shutter array into a substantially isotropic light beam directed toward the proper incident direction of the optical shutter array; and a diffuser tube that guides the light emitted from the diffuser tube to the optical shutter array. It is characterized by having a lie I guide.

[For production]

According to the present invention, the light of Taro from the lamp is R,llll'l
This light is focused by the reflecting mirror and enters the diffuser tube, where it is reflected multiple times to achieve isotropy and to ensure that it is uniform and sufficient in the longitudinal direction of the optical shutter array. The light is dispersed at the leading end, enters a light guide, and is guided from the light guide to a light sheeter array to expose a photoreceptor.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

1 to 3 show one embodiment of the present invention.

The light shutter array light source 20 of this embodiment uses a halogen lamp 2 as a light emitting body, which is a type of lamp with a large emission.
1 is used. This halogen lamp 21 is classified into the category of point light source, and this halogen lamp 2
In order to uniformly disperse the visible light beams from 1 to 11 in the longitudinal direction of the LCS array 9, a dike mirror 22, a type of reflecting mirror, a diffusion tube 23, etc. are provided. ing. This dichroic mirror 22 focuses the light emitted from the halogen lamp 21 in the arrangement direction of the LCS array 9. In addition, the dichroic mirror 22 does not reflect the infrared rays emitted from the halogen lamp 21, but allows the infrared rays to pass through itself and escape to the outside.This is because in this embodiment, only visible light is supplied to the LCS array 9. By doing. When infrared rays are also supplied to the LCS array 9, the dichroic mirror 22 is used as a normal reflecting mirror. An infrared cut filter 24 that blocks infrared rays from the light emitted from the halogen lamp 21 is provided between the halogen lamp 21 and the dichroic mirror 22 and the expansion RLI tube 23. This infrared cut filter 24 is also removed if it is not needed. The diffusion tube 23 reflects the light emitted from the halogen lamp 21 and the dichroic mirror 22 almost parallel to the arrangement direction of the LCS array 9 on its inner peripheral surface, and
．． , the light beam is almost isotropic toward the proper direction of incidence on the CS array 9. In this embodiment, the sedge body 25 has a circular cross section and a length equal to the length of the LCS array 9 in the arm direction. The tube body 25 is formed to have approximately the same length and taper toward the direction in which the light travels, and a reflector 26 that reflects light is provided at the innermost part of the tube body 25, and a light guide is provided through a slit 27 at the lower end. How is it connected to 8? The inner circumferential surface 2 J a of the tube body 25 is preferably painted white to increase the reflectance.

Light source 20 for an optical shutter array formed in this way
This allows light to be introduced from the lower end surface of the light guide 8 to the optical shutter array. FIG. 3 shows a state in which the LCS array 9 as an example of an optical shutter array is connected to the light source 20 for the optical shutter array of this embodiment. LCS array 9 in the same figure
The photoconductor 16 can be exposed to light by contacting the photoreceptor 16. That is, at the lower end of the liquid crystal 12 of the LCS array 9,
Thin film-like protection IY! A fiber plate 29 made of resin or glass is connected via J2B. In the center of the fiber plate 29, optical fibers F and T30, which are resin or glass optical fibers hardened with resin or glass and serve as coupling members extending in the vertical direction, are buried along the width direction of the photoreceptor 16. The lower surface 29a of the fiber plate 299 is polished so that the portion where the optical fibers 30 are located is located at the bottom in order to uniformly contact the photoreceptor 16 and reduce frictional resistance. It is formed in a curved shape. Note that when the fiber plate 29 is made of resin, the protective layer 28 prevents the transparent mJi13B from being formed well due to insufficient smoothness of the upper surface, and also prevents the fiber plate 29 or the optical fiber plate 29 from being formed properly. When the fiber group 30 is made of resin, this is to prevent impurities from entering the liquid crystal 12 from the resin part. fiber r
, T 30 is buried, there is no need to provide the protective layer 28.

Next, the operation of this embodiment will be explained.

When the halogen lamp 21 is energized, the halogen lamp 21
A very large amount of light ω is emitted from the infrared ray cut filter 24 , and some of the light is directed directly to the infrared cut filter 24 and the other light is directed to the dichroic mirror 22 . The light directed toward the dichroic mirror 22 is reflected by the inner surface of the dichroic mirror 22 while the infrared rays pass through the dichroic mirror 22 and are missed, and travels toward the infrared cut filter 24 and the diffusion tube 23, and is directly emitted from the halogen lamp 21. The light directed toward the infrared cut filter 24 becomes a luminous flux that is parallel to the arrangement direction of the LCS array 9. After that, by passing through the infrared cut filter 24, the infrared rays are removed, and the pure white light enters the tube body 25 of the diffusion tube 23, is reflected by the inner circumferential surface 25a of the tube body 25, and is dispersed. Since the inner circumferential surface 25a has a tapered shape, the light ω in the axial direction of the tube body 25 is uniformly dispersed, and isotropically directed to the appropriate direction of incidence on the LCS array 9. After that, the light passes through the slit 27 of the tube body 25 and enters the light guide 8 .

Thereafter, the light incident on the light guide 8 is uniform in the longitudinal direction and is incident on the LCS array 9 with sufficient photoelectricity.

Thereafter, the light introduced into the LCS array 9 is transmitted through the transparent electrodes 13A and 13B, which are controlled according to the input image information.
The light passes only through the transparent part of the liquid crystal 12, which is divided into a transparent part and an opaque part by applying a voltage to the optical fiber, and reaches the optical fiber group 30. By passing through the optical fiber group 30, the light is uniformly deposited on the photoreceptor 16. Ru. By forming an image on the photoreceptor 16, the charges on the photoreceptor 16 are selectively removed and an electrostatic latent image is formed.

According to this embodiment, a lamp with a large emission level (1) is used as a light emitter, and the light emitted from the lamp classified as a point light source is converted into an LCS using a dichroic mirror 22 and a diffusion tube 23, which are reflectors. It is possible to make the light incident on the array 9 uniformly in the longitudinal direction and with sufficient light intensity at an appropriate incident direction, and the configuration is also very a
111, which is easy to manufacture and can reduce costs.

Note that the lamp serving as the light emitting body may be replaced with a lamp equipped with a reflecting mirror other than the guichroic mirror 22 depending on the overall required light E.

Further, the present invention is not limited to the embodiments described above, and various changes can be made as necessary.

〔Effect of the invention〕

As explained above, according to the present invention, a lamp with a large amount of light emission can be used as a light emitter, the light utilization efficiency is high, sufficient light ω can be supplied to the optical shutter array, and the structure is simple. It has advantages such as easy manufacture and low cost.

[Brief explanation of drawings]

1 to 3 show an embodiment of the light source for an optical shutter array according to the present invention, in which FIG. 1 is a partially cutaway perspective view, FIG. 2 is a plan view, and FIG. 3 is on the left side of FIG. 2. 4 is a vertical sectional front view showing a conventional light source for an optical shutter array, and FIG. 5 is a perspective view showing another conventional example. 8...Light guide, 9...LCS array, 10A
. 10 [3...Glass plate, 12...Liquid crystal, 13A, 1
3B...Transparent electrode, 16...Photoreceptor, 20...Light source for optical shutter array, 21...Halogen lamp, 2
2... Dichroic mirror, 23... Diffusion tube, 2
4... Infrared cut filter, 25... Tube body, 2
5a...Inner peripheral surface, 26...Reflector, 27...Slit.

Claims (1)

[Scope of Claims] 1) A light source for an optical shutter array that illuminates an optical shutter array arranged in a longitudinal direction, including a lamp that generates light, and a lamp that emits light from the lamp in the arrangement direction of the optical shutter array. a reflector that focuses the light from the lamp and the reflector, a diffuser tube that reflects the light emitted from the lamp and the reflector so that it becomes a substantially isotropic light beam directed toward the appropriate direction of incidence of the light shutter array; A light source for an optical shutter array, comprising a light guide that guides light to the optical shutter array. 2) The light source for an optical shutter array according to claim 1, wherein the lamp is a halogen lamp, and the diffusion tube has a tapered inner circumferential surface that tapers toward the direction in which the light travels.