JPS63148759A - Optical read sensor - Google Patents

Abstract

PURPOSE:To shorten the alignment time at the time of assembly, and to miniaturize the titled sensor by providing a light source, a photoelectric converting part, an illuminating lens and a convergent lens on a substrate. CONSTITUTION:On one face of a transparent substrate 5, the illuminating lens 6 and the convergent lens 7 are formed by a refractive index distribution type planar microlens. Subsequently, a light shielding film 8 is formed, and on the other face, the light source 9 of an LED and a photoelectric converting part 10 consisting of a photodiode array are formed. Also, a photodiode array driving scanning circuit 11, and a scanning circuit 14 for driving a light source are formed. In such a way, as soon as an original 1 is fed, the light source 9 is synchronized with the converting part 10 and lighted, and a reflected light is brought to image formation on the converting part 10 and converted to an electric signal. Accordingly, a position relation can be fixed exactly, the alignment time can be shortened, and the sensor can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical reading sensor used for reading images in facsimiles, printers, image scanners, copiers, and the like.

[Prior art] Conventionally, this type of device is called a contact image sensor.
As shown in FIG. 5, a photoelectric conversion unit 10 such as a CCD type photodiode array, an MO8 type photodiode array, a photodiode array using amorphous silicon, CdS, Se, etc., and a light source 9 that irradiates light onto the document area.
Also known is a lens system 14 that focuses light from the document onto a photoelectric conversion section.

The optical reading sensor described above is attracting attention as a small and lightweight reading device.

[Problems to be solved by the invention] However, the above-mentioned conventional charging conversion device has a lens system,
Since the light source and the photoelectric conversion section are each configured independently, there is a problem in that trimming such as optical axis alignment is required when fixing to a facsimile machine or the like. In addition, the optical axis etc. may shift during use, and when this shift occurs, there are disadvantages such as a decrease in output, a decrease in resolution, and a decrease in brightness and darkness.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes an elongated light source section, an elongated photoelectric conversion section and its scanning circuit, and condenses light from the light source onto a document. An irradiation lens that causes the light to emit light and a condensing lens that focuses reflected light from the original onto a photoelectric conversion unit are provided on one substrate or a composite substrate that is a composite of a plurality of substrates.

The above-mentioned irradiation lens and/or condensing lens may be configured using a normal lens such as a spherical or aspherical lens, but may be configured using a gradient index lens provided within a transparent substrate such as glass or plastic. It is preferable to do so.

Further, the lens may be composed of a single lens or a plurality of lenses.

The substrate on which the light source section, photoelectric conversion section, lens, etc. are provided is:
It may be a single substrate or a composite substrate made by gluing multiple plates together. Further, when a long light source section is sequentially driven and used, it is preferable that the drive circuit for the light source section is also based on the substrate.

It is also possible to scan the light source in synchronization with the scanning of the photoelectric conversion section, and a light source scanning circuit can also be attached. In particular, when trying to use a single lens as a condenser lens,
This is preferable since it has the effect of reducing noise light incident on the photoelectric conversion section.

[Implementation example] An embodiment of the present invention will be described below based on the drawings.

On one side of a transparent substrate (5) such as glass or plastic,
An illumination lens (6) for focusing the light from the light source (9) onto the original (1), and a condensing lens (6) for focusing the reflected light from the original (1) onto the photoelectric conversion unit (4). 7) was formed.

These two lenses (6) and (7) are from Japanese Patent Application Publication No. 59-178.
A gradient index flat plate microlens known as 719 or the like is used. The lenses (6) and (7) have a hemispherical shape, and one lens is provided corresponding to one bit of the photoelectric conversion section (10). Next, a light shielding film (8) for shielding leaked light is formed on the transparent substrate (5) using a metal film such as Cr. Next, on the substrate opposite to the original (1), a light source (9) and a photoelectric conversion unit are respectively placed at positions where the light from the original (1) is focused by lenses (8) and (7). (10)
was formed.

Photoelectric transformer 1j [(10) is amorphous silicon, Cd
A thin film photodiode array made of S, Se, etc., and a scanning circuit (IC) for driving the photodiode array.
(11) and a scanning circuit (IC) for driving the light source (14)
were placed on the same board.

The photoelectric conversion unit (10) may be a photodiode array using a Si substrate such as a CCD or MOS.
It can be used by fixing it with a transparent adhesive such as epoxy resin.

The light source (9) was an LED and was fixed with a transparent adhesive such as epoxy resin. FIG. 1 shows a schematic cross-sectional view of the created optical reading sensor.

This optical reading sensor detects the light source section (
9) is turned on in synchronization with the charging conversion unit, and the lighting lens (
Light is irradiated onto the original (1) through 6), and the light from the condensed parts such as letters, diagrams, pictures, etc. is imaged on the photoelectric conversion unit (10) through the condensing lens (7), and photoelectric conversion is performed. Part (10)
This converts optical signals into electrical signals according to the brightness of the light.

In the above embodiment, one transparent substrate is used as the substrate, but as shown in FIG. It may also be a composite substrate in which a separate substrate (13) on which a .

In addition, as shown in FIG. 3, two transparent substrates (5a),
(5b) are provided with illumination lenses (8a) and (6), respectively.
b) and the condensing lenses (7a) and (7b) can also be combined to form an illumination lens and a condensing lens. It is preferable to bond two gradient index lenses together with their flat portions facing each other in this way, since a spherical compound lens can be produced and a highly accurate lens can be produced. Also, the board on the original side (
If the thickness of the transparent substrate (5a) is adjusted to the distance to the document surface, the transparent substrate (5a) can also be used as a protective cover for the document (1).

In order to obtain a photoelectric conversion device with even higher resolution, as shown in FIG. forming condensing lenses (7a) and (7b), respectively;
Transparent substrates (5b) and (5c) are connected to a condensing lens (7a)
, (7b), (7c), and (7d) were bonded together so as to form a substantially straight line. Thereafter, a transparent substrate (5a) and a transparent substrate (5d) were further bonded to the upper and lower parts of the bonded substrate to form a composite substrate. When a composite substrate configured in this manner is used, good optical reading can be realized because the resolution of the condensing lens system is high.

Furthermore, if the condensing lens is used as a one-to-one imaging system as in the above embodiment, the noise light incident on the photoelectric conversion unit is reduced, so good reading can be achieved without providing a light source drive circuit (scanning circuit). I can do it.

The optical reading sensor of the above embodiment uses photolithography to create the refractive index distribution type lens, the light shielding film, and the photoelectric conversion element, so the manufacturing position can be accurately determined based on the external shape of the transparent substrate. can be determined. Furthermore, positioning can be easily performed when bonding or fixing using an adhesive. In addition, a light source, a photoelectric conversion element,
and lens system are aligned and provided,
The alignment time when assembling a facsimile machine, etc. is greatly reduced.

Further, the optical reading sensor of this embodiment is very small, and the device to which the optical reading sensor is mounted can be downsized.

[Effects of the Invention] According to the present invention, the light source, photoelectric conversion section, illumination lens, and condensing lens are provided on one substrate, so the optical reading sensor becomes very compact and the assembly time is reduced. The time required for alignment etc. is reduced.

Furthermore, since the positional relationship can be fixed accurately and reliably, the resolution of optical reading can be maintained higher than in the conventional case.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views schematically showing an optical reading sensor of the present invention prepared in an example, and FIG. 5 is a side view schematically showing a conventional optical reading sensor. Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A long light source section, a long photoelectric conversion section and its scanning circuit, an illumination lens that focuses light from the light source on the document, and a lens that focuses reflected light from the document on the photoelectric conversion section. An optical reading sensor in which a condenser lens is provided on one substrate or a composite substrate made of multiple substrates. (2) The optical reading sensor according to claim 1, wherein the illumination lens and the condenser lens are gradient index lenses provided in a substrate.