JPS61243438A - Optical element for copying machine - Google Patents

Abstract

PURPOSE:To produce an optical element easily at low cost by arranging refractive index distribution type image forming elements on a porous glass base and forming an original illumination light guide having thin and long openings in parallel to the row of said elements. CONSTITUTION:The refractive index distribution type image forming plural elements 6 extending from the upper face of the base 4 to its lower face are arranged in a straight line on the porous glass base 4 of the optical element 2 and the original illumination light guide 8 having thin and long openings in parallel to the row of said elements 6 at the upper face of the base 4 and its lower slope face. An original 14 is illuminated with a long light source 10 through the light guide 8 to project the reflected light through the elements 6 on the surface of a photosensitive drum 16 and to form an image on it, thus permitting the optical element to be easily fabricated by forming the refractive index distribution type image forming elements and the original illumination light guide directly on the porous glass base.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical element used in a copying machine, and more particularly to an optical element having an imaging element array and an illumination light guide.

[Conventional technology]

Conventionally, in a scanning type copying machine, an optical element 20 as shown in a perspective view in FIG. 5(a) has been used.

That is, a plurality of imaging elements 22, which are gradient index fiber lenses, are arranged in a base body 21 made of resin, and the imaging elements 22 have openings on the upper and lower surfaces of the base body 21, and The openings are arranged in a straight line. This imaging element array is used to form an image of the document surface onto the surface of the photosensitive drum. On the other hand, a plurality of light guiding fibers 23 for illuminating the original are arranged on the base body 21.

The fibers 23 have one opening on the upper surface of the base body 21, and the openings are arranged in a row along the arrangement direction of the openings of the imaging element 22. The plurality of fibers 23 are bent and bundled together in the base body 21, and are made to protrude from the side surface of the base body 21. A point light source 24 is arranged at a position facing the protruding end surface of the fiber 23.

FIG. 5(b) is a front view showing the state in which the conventional optical element as described above is used. As shown in the figure, the light emitted from the light source 24 passes through the light guide fiber 23 and passes through the optical element 20.
The document 26 on the transparent document table glass 25 located above is illuminated. The thus illuminated original 26 is imaged by the imaging element 22 on the surface of a photosensitive drum 27 having a rotation axis parallel to the direction in which the imaging elements 22 are arranged.

[Problem that the invention seeks to solve]

However, the conventional optical elements for copying machines as described above are
A plurality of light guide fibers are bundled together in the middle and arranged in an appropriate direction, and then the light guide fiber array and the imaging element array are fixed and held in an appropriate arrangement and hardened with resin. Since it is manufactured through labor, it is extremely difficult to manufacture and the cost is high.

[Means for Solving the Problems] In view of the above problems, the present invention has been made to provide an optical element for a copying machine that can be manufactured relatively easily and at low cost. The optical element includes at least one gradient index imaging element extending from a surface facing the original to the other surface on a base made of porous glass.
The substrate is arranged in an array in rows, and the substrate has an elongated opening substantially parallel to the arrangement direction of the imaging element array on the surface facing the document, and extends to the other surface for document illumination. It is characterized in that a light guide path is formed.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described based on the drawings.

FIG. 1(,) is a perspective view showing a first embodiment of the optical element of the present invention, and FIG. 1(b) is a front view showing its usage state. In the figure, 2 represents the optical element of this example.

Reference numeral 4 denotes the base of the optical element 2, which is made of porous glass (for example, porous Pycoor glass manufactured by Corning Inc.). Reference numeral 6 denotes an imaging element composed of a gradient index lens, and the imaging element 6 extends from the upper surface to the lower surface of the base 4, as in the conventional optical element shown in FIG.

A plurality of imaging elements 6 are provided, and the openings on the upper and lower surfaces of the base of each element are arranged linearly. Reference numeral 8 denotes a light guide path for illumination, and the light guide path 8 has an opening on the upper surface of the base body 4 and the side slopes of the base body 4.

The openings on the top surface and side slopes of the light guide path 80 are in the form of a rectangle whose longitudinal direction is parallel to the arrangement direction of the imaging element array.

The optical element 2 of this embodiment as described above is manufactured in the following manner. That is, first, porous glass is shaped into the shape of the substrate 4 as shown in FIG. 2(a). Next, JP-A-58-49
As shown in Japanese Patent No. 639 (PC method), an imaging element 6 and an illumination light guide path 8 are formed in porous glass. The organic substance is impregnated into the glass by immersing it in an organometallic compound), and an appropriate amount of
A mother-turn light-shielding mask 30 is attached and exposure is performed as shown in FIG. Substances are removed from the cigaras by leaching.

In this way, the imaging element 6 and the light guide path 8 are formed as parts with a high refractive index with respect to the base body 4. In forming the imaging element 6, a gradient index lens can be formed by appropriately setting a mask pattern, exposure conditions, etc.

A long elongated light source 10 is disposed at a position facing the opening of the illumination light guide path 8 on the side slope of the optical element 2 as described above along the longitudinal direction of the opening. The light from the light source 10 passes through the light guide path 8 and illuminates the document 14 on the document table glass 1'2. The original 14 is transferred to the photosensitive drum 1 by the imaging element 6.
The image is formed on the surface of 6.

FIG. 3(a) is a perspective view showing a second embodiment of the optical element of the present invention, and FIG. 3(b) is a side view showing its usage state. In the figure, parts having the same functions as in FIGS. 1(a) and 1(b) are given the same reference numerals.

In this embodiment, a light guide path 18 is formed in the optical element 2 to guide reflected light from the original to the light receiving element. The light guide path 18 has openings on the upper surface of the base body 4 and the side slopes of the base body 4, and can be formed in the same manner as the illumination light guide path 8.

As shown in FIG. 3(b), a light receiving element 19 is arranged at a position facing the opening of the light guide path 18 on the side slope of the base 4 of the optical element 2. As shown in FIG. The light-receiving element 19 detects the amount of reflected light from the original 14 guided through the light guide path 18, and based on this, can control the amount of light emitted from the light source 10, the developing bias, etc. in order to perform copy development with optimum density.

FIG. 4(,) is a perspective view showing a third embodiment of the optical element of the present invention, and FIG. 4(b) is a front view showing its usage state. In the figure, parts having the same functions as in FIGS. 1(a) and 1(b) are given the same reference numerals.

In this embodiment, the opening shape of the illumination light guide path 8 is different from that in the first embodiment. That is, in this example,
This is to deal with the problem that uneven distribution of illuminance occurs at the opening position of the illumination light guide path 8 when the point light source 11 is used as the illumination light source.

That is, in order to illuminate the original 14 with uniform illuminance, the width of the low-illuminance part is made large and the width of the high-illuminance part is made small along the longitudinal direction of the light guide path 8.

〔Effect of the invention〕

According to the present invention as described above, a low-cost optical element for a copying machine that is relatively easy to manufacture is provided.

[Brief explanation of drawings]

1(a), 3(a) and 4(-) are perspective views of the optical element of the present invention, and FIG. 1(b) and 3(b) are perspective views of the optical element of the present invention.
) and FIG. 4(b) are front views showing their usage conditions, respectively. FIGS. 2(a), 2(b), and 2(C) are diagrams showing an example of a method for manufacturing the optical element of the present invention. FIG. 5(&) is a perspective view of a conventional optical element, and FIG. 5(b) is a front view showing its usage state. 2: Optical element, 4: Substrate, 6: Image forming element, 8: Light guide path for illumination, 10, 11: Light source, 12: Original table glass, 14:
Original, 16: Photosensitive drum, 18: Light guide path, 19: Light receiving element. Agent Patent Attorney Minoru Yamashita Figure 1 (a) Figure 1 (b) (a) (b) (C) Figure 3 (0) Figure 4 (G) Figure 4 (b) Figure 5 (0) Figure 5/

Claims (2)

[Claims] (1) A substrate made of porous glass is provided with at least one row of gradient index imaging elements extending from one surface facing the original to the other surface, and the substrate is provided with an original. for use in a copying machine, characterized in that a light guide path for document illumination is formed, which has an elongated opening substantially parallel to the arrangement direction of the imaging element array on a surface facing the image forming element array, and extends to the other surface. optical element. (2) A copy according to claim 1, wherein the base body is provided with a light guide path extending from the surface facing the document to the other surface for guiding reflected light from the document to a light-receiving element. Machine optical element.