JPS6061701A - Lens array - Google Patents

Abstract

PURPOSE:To maintain the adequate position relation with a photoelectric sensor even if temp. and humidity fluctuate and to prevent the fluctuation of the optical axis by fixing respective lens elements by means of an adhesive agent and packing further a rubber-like elastic material into the space betweens the lens elements. CONSTITUTION:Lens elements L1, L2, ..., Ln each having a convex lens on one side are formed of a transparent plastic resin such as acryl or polycarbonate. These lens elements are connected by joining materials 5 and are formed into an array shape. The materials 5 consist of a rubber or foamed urethane resin. The lens array is further adhered and united by an adhesive agent 3 to a phptoelectric sensor 4 formed on a ceramic or metallic base plate. The expansion and shrinkage of the respective lens elements are absorbed or compensated by the material having rubber-like elasticity, by which the optical axis of each lens element is made hardly deviatable and the adequate positional relation between each lens element and a photoelectric sensor is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens array in which a plurality of lens elements are arranged on a substrate.

When obtaining a transmitted image or a copy image of an original using a photocopying device, the original is exposed to light and the reflected light is detected by a photodetector consisting of a photoelectric conversion element via an optical lens system. .

In this case, a lens array is used as the optical lens system, in which a large number of lens elements (convex lenses) are arranged in one or more rows with a length approximately the same as the width of the original document and are brought into close contact with each other. At this time, in order to maintain a proper positional relationship between each lens element and the photoelectric sensor section and to reduce fluctuations in the optical axis of the lens elements, it is conceivable to combine and integrate the lens array and the photoelectric sensor section. However, when such a lens array is made of transparent plastic resin such as acrylic or polycarbonate and is used in combination with a photoelectric sensor formed on a substrate such as glass, ceramics, or metal, the lens elements and The photoelectric sensor part is made of different materials, so it may expand due to changes in temperature and humidity.
The magnitude of the contraction is different, and as a result, deviations from the proper positions and fluctuations in the optical axis occur, resulting in problems in reading the original.

The present invention has been made in view of the above points, and is an optical imaging device consisting of a lens array and a photoelectric sensor section, which maintains an appropriate positional relationship with respect to the photoelectric sensor even when there are fluctuations in temperature and humidity, and maintains an optical axis. An object of the present invention is to provide a lens array that can prevent fluctuations in .

Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, lens elements LL, L2. have a convex lens on one side.・Reason: Ln is made of transparent plastic resin such as acrylic or polycarbonate. These lens elements are connected by a bonding material 5 and formed in an array. The bonding material 5 is made of a rubber-based or foamed urethane-based resin b'. Further, this lens array is bonded and integrated with a photoelectric sensor 4 formed on a glass, ceramic, or metal substrate via an adhesive 3 to create an optical imaging device.

Differences in the materials of the lens element and the photoelectric sensor section cause differences in expansion and contraction due to changes in temperature and humidity, but each lens element is fixed to the appropriate position of the photoelectric sensor via the adhesive. Furthermore, since each lens element is bonded by providing a gap between each lens element and filling at least a portion of that gap with a material having rubber-like elasticity, expansion and contraction of each lens element is prevented. Because it is absorbed or compensated by a substance with rubber-like elasticity and does not easily affect other lens elements, it is difficult for the optical axis of each lens element to shift, and the proper alignment between each lens element and the photoelectric sensor is avoided. The positional relationship is maintained.

The term "substance that provides rubber-like elasticity" refers to a material that bonds with each lens element and has cushioning properties that can adapt to the expansion and contraction of the lens element and photoelectric sensor. Another example is urethane resin.

When forming a lens array by connecting several lens elements with a bonding material, usually the entire surfaces of adjacent lens elements parallel to the optical axis are bonded with a rubber-like elastic material, as shown in Figure 1. However, the present invention is not limited to this, and at least a part of the surface of the lens element parallel to the optical axis may be bonded with a substance having rubber-like elasticity. That is, Fig. 2 shows a part of the surfaces of adjacent lens elements parallel to the optical axis bonded with the above material, and Figs. 3 and 4 show a part of the surfaces of adjacent lens elements parallel to the optical axis. This is a case where the lens elements are bonded one by one using the above-mentioned material, and FIG. 3 shows the entire surface of the lens element parallel to the optical axis, and FIG. 4 shows a case where a part of the lens element is bonded.

In the above embodiment, the lens array manufactured according to the present invention is bonded and integrated with a photoelectric sensor formed on a glass, ceramic, or metal substrate through an adhesive.
However, although an optical imaging device is created, other methods may also be used. That is, a frame made of gold maple or plastic resin is fixedly attached to the lens array made according to the present invention, and the frame is fitted with a frame separately provided on a substrate on which a photoelectric sensor is formed, and if necessary, This is a method of fixing with screws or fasteners.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a lens array according to the present invention. FIGS. 2 to 4 are longitudinal cross-sectional views showing other embodiments of the present invention. In the figure, Ll, L2. ......, Ln: Lens element 2
: Convex lens part 3 : Adhesive 4 : Photoelectric sensor 5 : Bonding material 1 Fig. 3 Fig.

Claims (2)

[Claims] (1) In a lens array in which a plurality of lens elements made of transparent plastic resin are arranged so that their optical axes are parallel, at least a portion of the adjacent lens elements parallel to the optical axis is made of rubber-like elastic material. A lens array bonded with a material that has (2) @All surfaces parallel to the optical axis of the contacting lens elements,
The lens array according to claim 1, which is bonded with a substance having rubber-like elasticity.