JPS61151608A - Image-forming element - Google Patents

Abstract

PURPOSE:To reduce the thickness difference of an image-forming element, to improve the precision and to use it for an electrophotographic copying machine or the like by forming lenses, which are joined to a reflecting part where roof-shaped reflecting surfaces are formed continuously, so that the incidence or reflecting surface of light of the image-forming element has a refractive index distribution. CONSTITUTION:Roof-shaped surfaces 11a and 11b forming right angles are formed continuously, and a reflecting film is formed on surfaces 11a and 11b by vacuum evaporation of Al, Ag, or the like to form the reflecting part, and the incidence surface of light and the exit surface of reflected light are formed to a common plane 12, thereby producing an image-forming element 10 consisting of a roof mirror lens array. A mask matched to the diameter of plane lenses 13 is used to diffuse a dopant on the plane 12 by the ion exchange diffusing method, the plastic diffusion polymerizing method, or the like for the purpose of forming plane lenses 13 on the plane 12, and lens parts having the image-forming function are formed. Thus, the image-forming element is obtained which is thin and has a high precision because of junction of the reflecting part and lenses and has a high image-forming capacity and is suitable for the optical system of the electrophotographic copying machine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an imaging element that can be used in an optical system of an electrophotographic copying machine or the like.

(Prior Art) For example, an imaging element called a roof mirror lens array is sometimes used in an exposure optical system of an electrophotographic copying machine.

The roof mirror lens array is provided integrally with a reflecting section in which a roof-shaped reflecting surface is continuously formed, and corresponding to the roof-shaped reflecting surface of this reflecting section.

It has a mirrored lens part, and even if the focal length of the lens is increased, the distance between the lens and the reflective part can be extremely shortened, making it suitable for mirror-travel type mirrors that require a long focal length. Suitable for application to electrophotographic copying machine optical systems.

Related conventional techniques include those described in Japanese Patent Application Laid-open No. 56-140301 and Japanese Patent Application Laid-Open No. 56-140302.

7 to 9 show an example of an optical system using an imaging element called the roof mirror lens array described above, in which light from an object 0 is reflected by a mirror 3 having two reflecting surfaces 3a and 3b.
After being reflected by one of the reflecting surfaces 3a, it passes through the lens surface 2 of the imaging element 1 made of a roof mirror lens array, is reflected by the roof-shaped reflecting surface 4 of the imaging element 1, and passes through the lens surface 2 again. It is then reflected by the other reflective surface 3b of the mirror 3,
Image (2) of object 0 is focused at a predetermined imaging position by the imaging action of lens surface 2.

The lens surface 2 has a plurality of spherical surfaces arranged in a row to form a lens array, and the roof-shaped reflective surfaces 4 are formed continuously in pairs facing each lens surface 2. ing. The mirror 3 is elongated (formed) in the direction in which the lens surfaces 2 are arranged.

In FIG. 7, the position of the object 0 and the position of its image (2) are symmetrical with respect to the optical system consisting of the mirror 3 and the imaging element 1. If the above optical system is an exposure optical system of an electrophotographic copying machine, the position of object 0 is the document surface, and the position of image 2 is the photosensitive drum surface.

The imaging element 1, in which a roof-shaped reflective surface and a corresponding lens surface are continuously formed, is usually made by injection molding or injection compression of a thermoplastic resin. In some cases, thermosetting resin may be used for cast molding, but mass productivity is low.

However, when an imaging element is molded from a resin and then cooled, the imaging element shrinks unevenly due to uneven thickness, making it impossible to obtain an accurate flat surface, which may reduce imaging performance. In particular, if the lens surface is formed integrally with the roof-shaped reflective surface as in the conventional example, the unevenness of the wall thickness becomes even more pronounced, making it even more difficult to obtain a desired shape after molding.

(Objective) The object of the present invention is to provide a reflecting section in which a roof-shaped reflecting surface is continuously formed, and a reflecting section in which the reflecting section has a reflecting section so that the incident light to the reflecting surface of the reflecting section and the reflected light from the reflecting surface are transmitted. In an imaging element which has a lens part integrally formed with the reflective part corresponding to a surface and is made by resin molding, the imaging element is formed by forming the lens part into a flat lens surface. It is an object of the present invention to provide an imaging element which can minimize the deterioration of imaging performance by minimizing the unevenness of the wall thickness of the element, and which can be made compact.

(Structure) The present invention includes a reflecting section in which a roof-shaped reflecting surface is continuously formed, and a reflecting section configured to transmit light incident on the reflecting surface of the reflecting section and reflected light from the reflecting surface. Correspondingly, in an imaging element comprising a lens part formed integrally with the reflection part, the lens part is formed by providing a refractive index distribution on an incident surface or a reflection surface of the imaging element, It is characterized in that the lens portion is shaped like a flat plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 10 indicates an imaging element made of a roof mirror lens array. This □ imaging element 10 is continuously formed with roof-shaped surfaces 11a and llb that are perpendicular to each other. The roof-shaped surface 11a of the imaging element 10
, llb, a reflective film is formed by vacuum-depositing AI, A, etc., and the roof-shaped surfaces 11a, flb
are reflective surfaces, and these continuous reflective surfaces constitute a reflective section. The plane of incidence of light to this reflecting section and the plane of exit of reflected light from the reflecting section form one common plane 12 without any unevenness. Plane 1 that forms this person's exit surface
2, a flat lens 13 is formed at a position facing the pair of roof-shaped reflective surfaces 11a and llb.

The flat lens 13 can be manufactured by applying selective diffusion technology used in semiconductor integration technology. For example, a mask is formed according to the diameter of the lens to be formed, and then ion If the dopant is selectively diffused according to the mask pattern by the exchange diffusion method, plastic diffusion polymerization method, ion electric field transfer method, etc., the plane 12 forming the entrance/exit surface will have a refractive index distribution according to the mask pattern. A lens portion having an image forming function can be formed.

In addition, the formation of the flat plate lens 13 and the roof-shaped surfaces 11a, l
The order of formation of reflections in lb is not particularly limited.

FIG. 2 shows how the imaging element 10 is used. As shown in FIG. 2, the incident light from the flat surface 12 passes through the flat plate lens 13 and is reflected by one reflective surface 11a and the other reflective surface 11b, which form a roof-shaped reflective surface, and is reflected again by the flat plate lens. By passing through 13, the light is focused at a predetermined position by the imaging action of the flat lens 13, and an image is formed.

According to the above embodiment, since the lens part is flat and has no partial protrusion, the uneven thickness of the entire imaging element is improved, and the flatness accuracy when molded with synthetic resin is improved. It also has fewer protruding parts, making it more compact.

The flat lens portion does not necessarily have to be provided on the exit surface of the imaging element. As shown in FIGS. 3 and 4, the roof-shaped reflective surfaces 21a and 2 of the imaging element 20
1b may be formed with flat plate lenses 23a and 23b, respectively. These flat lenses 23a and 23b are formed by masking the roof-shaped reflective surfaces 21a and 21b into a predetermined shape, respectively, and then applying the flat plate lens forming method described above. Form. In the case of this embodiment, the flat lens 23a,
23b, a reflective film is formed on the roof-shaped surface 21a121b to form a reflective surface.

According to the embodiments shown in FIGS. 3 and 4, the light incident from the plane 22 forming the person exit surface passes through the flat lens 23a, is reflected by the reflective surface 21a, passes through the flat lens 23a again, and then After passing through the flat lens 23b, the light is reflected by the reflective surface 21b, passes through the flat lens 23b again, emerges from the flat surface 22, and is condensed at a predetermined position.

The embodiments of FIGS. 5 and 6 also have a roof-shaped surface 3 of the imaging element 30.
Although flat lenses are formed in 1a and 3b,
In this embodiment, the pair of roof-shaped surfaces 31a and 31b are masked and then subjected to the flat lens forming method described above.
, 31b is formed. After forming the flat lens 33, the roof-shaped surfaces 31a, 3
A reflective film is formed on 1b to form the roof-shaped surfaces 31a, 31.
Let b be the reflective surface. In this embodiment, the light incident from the plane 32 forming the person exit surface passes through the flat plate lens 33, is reflected by the reflective surface 31a, passes through the flat plate lens 33 again, and then passes through the flat plate lens 33 and then reflects by the reflective surface 31b. The light passes through the flat lens 33 again, exits from the plane 32 that forms the human exit surface, and is condensed at a predetermined position.

According to the embodiments shown in FIGS. 5 and 6, compared to the embodiments shown in FIGS. 3 and 4, it is possible to form a flat plate lens on a plane more efficiently, resulting in improved light utilization efficiency. There is an advantage to doing so.

In addition, a reflective part in which a roof-shaped reflective surface is formed continuously,
The lens portion made of a flat lens array may be formed separately, and then both may be fixed together.

(Effects) According to the imaging element of the present invention, since the lens part that is integrally formed in correspondence with the reflecting part in which the roof-shaped reflecting surfaces are continuously formed is a flat plate lens, the imaging element becomes thinner. The difference in thickness is reduced, and when the imaging element is manufactured by molding synthetic resin, the shape accuracy of the molded product is improved, and the imaging performance can be improved.

Furthermore, since the lens portion does not protrude, there is an advantage that it becomes compact.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a plan view of the same as above, FIG. 3 is a plan view of another embodiment of the present invention, FIG. 4 is a front view of the same as above, and FIG. is a plan view showing still another embodiment of the present invention, FIG. 6 is a front view of the same as above, FIG. 7 is a side view of an example of the conventional imaging element, FIG. It is also a plan view. 11a s llb 121a % 21b -31a
s 31b ----- One roof-shaped reflective surface, 13.
23a, 23b, 33---One flat lens portion. Kaqhei

Claims (1)

[Claims] a reflecting section in which a roof-shaped reflecting surface is continuously formed; and a reflecting section corresponding to the reflecting surface so that light incident on the reflecting surface of the reflecting section and light reflected from the reflecting surface are transmitted. In the imaging element having a lens part integrally formed, the lens part is formed by providing a refractive index distribution on the incident surface or the reflective surface of the imaging element, and the lens part is formed into a flat plate shape. An imaging element characterized by: