JPH03214106A - Light guide array sheet - Google Patents

Abstract

PURPOSE:To form the rod-shaped photoconductor array sheet which is not disordered efficiently by arranging many short rod-shaped photoconductors made of plastic and joining at least their one-end surfaces together with an adhesive. CONSTITUTION:The rod-shaped photoconductor array is formed by sandwiching a rod-shaped photoconductor array sheet of specific length at a specific position in two array substrates which are applied with an adhesive previously and have rod-shaped photoconductor array grooves, pressing the sheet with both the surfaces of the substrates, and setting the adhesive as specified. Therefore, when the sheet is adhered to the array substrates, no excessive jig is required, so a jig is never stained with an excessive adhesive on the substrates. Consequently, the rod-shaped photoconductor array can be assembled more efficiently and accurately than a conventional method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a light guide arrangement sheet suitable for efficiently producing a plastic light guide array.

[Prior Art] Among the light guides, a gradient index rod light guide array, in which a large number of short gradient index rod light guides are arranged and joined on both sides by an array substrate, is used in copying machines, copying machines, etc. It is usefully used as an image reading sensor for facsimiles or electronic blackboards.

These graded refractive index rod-shaped light guide arrays have grooves for storing the light guides, and short light guides are precisely arranged in the grooves on the surface of the array substrate on which an adhesive is applied. Place an array substrate coated with adhesive on top of this and pressurize it, or
Alternatively, rod-shaped light guides are arranged and sandwiched between two upper and lower array substrates, and an adhesive is press-fitted between the two array substrates.

[Problems to be Solved by the Invention] In the method of arranging and bonding rod-shaped light guides on an array substrate coated with adhesive in advance, it is necessary to firmly bond the rod-shaped light guides to the surface of the array substrate. Since a large amount of adhesive is used, problems such as adhesive adhering to areas where adhesive application is unnecessary and impairing the characteristics of the array may occur, and it is difficult to accurately supply and arrange the light guides in the grooves of the array substrate. It was difficult to control the process, as it required a repair process to correct it, and it was difficult to improve productivity.

In addition, the bonding agent press-in method tends to disturb the arrangement of the rod-shaped light guides arranged in the array substrate when press-fitting the bonding agent into the array substrate, so it is not suitable as an assembly method for arrays that require accurate image transmission. It had many difficulties.

[Means for Solving the Problem] Therefore, the present inventors are currently considering a method for efficiently manufacturing a rod-shaped light guide array without the above-mentioned inconveniences, and have found that the rod-shaped light guide array can be made in advance. The present invention was completed after discovering that the object could be achieved by arranging a large number of short plastic rod-shaped light guides and bonding an adhesive to at least one end surface of the light guides. A rod-shaped light guide arrangement sheet is characterized by the following.

The plastic rod-shaped light guide used in carrying out the present invention may include a monomer capable of providing a low refractive index polymer such as fluorinated alkyl methacrylate in a highly transparent plastic rod-shaped body such as polymethyl methacrylate. A gradient index rod-shaped light guide can be used by polymerizing and curing these 7-mers with a concentration distribution that gradually decreases from the center to the outer periphery.

To make the bar-shaped light guide array sheet of the present invention, short bar-shaped light guides are preliminarily arranged in a mold at regular intervals, and one end surface of the rod-shaped light guides is joined with an adhesive, particularly an adhesive tape. It is preferable to use

To make a rod-shaped light guide arrangement array using the rod-shaped light guide arrangement sheet of the present invention, a predetermined length is placed at a predetermined position in two array substrates in which grooves for rod-shaped light guide arrangement are coated with adhesive in advance. The rod-shaped light guide array sheet of the present invention prepared in the above manner may be sandwiched and pressed from both sides of the substrate, and then the adhesive may be subjected to a predetermined curing treatment. Since the rod-shaped light guide arrangement sheet of the present invention has the rod-shaped light guides arranged and temporarily fixed in predetermined positions, the rod-shaped light guides can be accurately and easily arranged in the grooves of the array substrate. Since no extra jig is required when adhering to the array substrate, there is no need to worry about the jig being contaminated by excess adhesive on the substrate, making the rod-shaped light guide array much more effective than conventional methods. Can be assembled efficiently and accurately.

Since the rod-shaped light guide used in the present invention is made of plastic, it is relatively easy to cut both end faces of the rod-shaped light guide, and the plastic rod-shaped light guide arrangement sheet of the present invention is sandwiched and bonded between two array substrates. After that, by cutting both end faces of the obtained light guide array, it is possible to obtain a light guide array that can perform accurate image transmission. On the other hand, since rod-shaped light guides made of inorganic substances such as glass have significantly inferior cutting workability compared to rod-shaped light guides made of plastic, it is extremely difficult to produce a light guide array using the same method as the present invention. difficult.

The present invention will be explained in more detail with reference to Examples below.

[Example] Example 1 Length: 250 mm, width: 10 mm, groove pitch: 0.95 mm,
Cut into a V-shaped mold with a groove depth of 0.3 ms and a length of approximately 18 mm, with a diameter of 920 μ and a refractive index distribution constant g value of 0.54 mm.
-' Arranging 240 plastic gradient index rod-shaped light guides made of polymethyl methacrylate and fluorinated methacrylate polymer with a center refractive index of 1.515 with the lens side surface protruding on one side; A double-sided adhesive tape (Scotch mending tape: manufactured by Sumitomo 3M, width 1B+nm) was attached to the protruding portion, and the rod-shaped light guide arrangement sheet was taken out from the mold.

Length 228nua, width 12mm, thickness 0.7wth,
Groove pitch 0.95mm, depth 0.28mm [1 groove 2
A plastic rod-shaped light guide array sheet prepared as described above was prepared by preparing two boards coated with a black ABS array array substrate with 40 pieces of adhesive (Araldite Rapid: manufactured by Chiha Geigy Limited). 2.
It was pressed under a pressure of kgf/cffl and the lens portion protruding from the substrate was cut to obtain an array of rod-shaped light guides.

Both end faces of this array were cut and polished to create a lens with a length of 7.0 m.
When an array was prepared, the arrangement of the plastic rod-shaped light guides in the U-groove of the array substrate was extremely good, and their parallelism was also extremely good. Moreover, excess adhesive could be easily removed by cutting the array.

The array thus obtained was further mixed with 20 parts by weight of dipentaerythritol hexaacrylate, 9 parts by weight of trimethylolpropane triacrylate 2O, 60 parts by weight of 2-propanol, 3 parts by weight of A photopolymerizable composition consisting of 1 part by weight of FAC F183 (manufactured by Inu Nippon Ink Kagaku Kogyo Co., Ltd.) was applied by dip coating, and then 2-propertool was volatilized.
0 was photocured with a chemical lamp to form a smooth cured coating film. This lens array had a lens length of 7.0 mm and a conjugate length of 14.4 M.

The resolution (MTF) was 61.5% at 25°C at a spatial frequency of 4j2P/nua.

Example 2 Using the rod-shaped light guide arrangement sheet produced in Example 1, the length was 2.
Sandwiched between two black ABS flat array substrates of 28 mm, width 11 m, and thickness 0.5 am coated with Araldide Drapinto (manufactured by Chipa Geigy Limited) 2
It was pressed under a pressure of kgf/cffl and the lens portion protruding from the substrate was cut to obtain a bar-shaped light guide array.

Since this array was temporarily arranged when producing the rod-shaped light guide arrangement sheet, the arrangement pitch interval and parallelism of the rod-shaped light guides were arranged with high precision even if no grooves were formed on the substrate.

As a result of the same surface treatment as in Example 1, the lens length was 7.
．． 0 mark, conjugate length 14.4 ++ un resolution (MTF)
is 59 at 25°C with a spatial frequency of 41P/l111II.
．． It was 2%.

Example 3 Length: 350 m, width: 10 nua, groove pitch: 0.95 m
1!1, a diameter of 920 Arm cut to a length of about 18 a + m in the ν groove of a mold having a V-shaped groove with a groove depth of 0.3 mm,
Refractive index distribution constant g value 0.54 Cylinder-1 center refractive index 1.51
368 Plastiac graded index rod-shaped light guide lenses (No. 5) were arranged in such a way that the side surfaces of the rays protruded from the ν groove, and a scontimending tape (width 18 mm, manufactured by Sumitomo 3M Co., Ltd.) was placed on the protruding part. was attached to obtain a rod-shaped light guide arrangement sheet.

A black array substrate with a length of 348 mm, a width of 11 mm, and a thickness of 0.5 mm was coated with Araldite Travid (manufactured by Ciba Geigy Ltd.), and the rod-shaped light guide arrangement sheet was sandwiched therebetween, and the process was carried out in the same manner as in Example 2. The rod-shaped light guide array was obtained by pressure bonding and surface hardening treatment.

This lens array has a lens length of 7. On++n, the conjugate length was 14.4 mm. Also, the resolution (MTF) is 4
7! It was 58.0% at 25°C at a spatial frequency of P/mm.

Comparative example: length 250m, width 10mm, groove pitch 0.95ff
A mold having a v-type groove of 1 m and a groove depth of 0.3 wa was cut into a length of about 18 m + diameter of 920 μ, refractive index distribution constant g value of 0.54 mm - 'center refractive index of 1.515. Arrangement of 240 distributed rod-shaped light guides, length 228m
Rardite Rapid (manufactured by Chiha Geigy Limited) on a black ABS array board with grooves of m, width 12 [+1111, thickness 0.7 ++un, groove pitch 0.95+++ m, groove depth 0.28 mm] The applied material was pressed down to transfer an array of gradient index rod-shaped light guides. At this time, the adhesive adhered to the mold, and the mold had to be cleaned each time.

Claims (1)

[Claims] 1. A light guide arrangement sheet comprising a large number of short plastic rod-shaped light guides arranged at regular intervals, and at least one end surface of the light guides is bonded with an adhesive.