JPH01181376A - Optical reader - Google Patents

Abstract

PURPOSE:To eliminate the need for complicated adjustment and to improve the productivity by arranging a composite mirror provided with plural mirrors on a unified forming. CONSTITUTION:The composite mirror 10 consists of the 1st reflection mirror 11 and the 2nd reflection mirror 12, the 1st reflection mirror 11 has a reflection face 13 and the 2nd reflection mirror 12 has a reflecting face 14. The reflecting faces 12, 14 are formed by coating the material face of the composite mirror 10 by a metallic film. The light reflected from an original P is reflected by the 1st reflection mirror 11 and the 2nd reflection mirror 12 and reaches an image forming section 17 via a throughhole 15. The plural mirrors are formed on the unified forming body, then it is not required to adjust the angle of the reflection mirrors 10, 12 and the productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical reading device, and particularly to an optical reading device used in a reading device such as an image scanner.

(Prior Art) Conventionally, there is a device of this type as shown in FIG. That is, in this device, the conveyance roller 100,
101 and driven rollers 102 and 103, is illuminated by a light source 105 such as a fluorescent lamp through an original platen glass 104, and the reflected image light is deflected by reflection mirrors 106 and 107 to form a final image. By forming an image on the photoelectric conversion element 109 using the image lens 108, the original Pl
The image above is read as an electrical signal.

Generally, in this type of device, the optical path length from the surface of the original 21 to the photoelectric conversion element 109 depends on the focal length of the imaging lens 108, and the longer the focal length and the longer the optical path length, the higher the resolution of image reading. Therefore, in order to guarantee high image quality, it is desirable to set the optical path length as long as possible.

However, setting the above-mentioned optical path length to be long leads to an increase in the size of the optical system and, in turn, to an increase in the size of the device, so conventionally, methods have been proposed for configuring the optical system compactly without shortening the optical path length. For example, in the conventional example shown in FIG.
The optical system is constructed so that the image light is reflected by the mirrors 106 and 107 and guided to the photoelectric conversion element 109, thereby making the optical system more compact.

(Problem to be Solved by the Invention) However, in such conventional examples, no matter which of the above methods is adopted, adjustment of the optical system, especially adjustment for correcting angular errors of multiple mirrors, is not required. Moreover, the angle adjustment must be performed with high precision so as not to deteriorate the image quality, so a complicated adjustment mechanism is required. The biggest reason why it becomes difficult to eliminate adjustments as the number of mirrors increases is that the coordinate and angular precision of each mirror accumulates. Because angles and coordinates are determined through multiple parts such as the base material to be fixed, adjustment work is performed without meeting the required accuracy. As a result, the adjustment process takes time,
There was a problem in that the production efficiency deteriorated and the cost of the device increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to reduce the size of the apparatus and further minimize the work required to adjust the angle of the mirror. The purpose is to provide a reading device at low cost.

(Means for Solving the Problems) The present invention having the above-mentioned objects provides an optical reading device that reads an image of a document by forming an optical image of the document on a reading device via a plurality of mirrors. It has a composite mirror on which multiple mirrors are provided.

(Function) In the present invention having the above configuration, since a plurality of mirrors are provided on the integral molded body, there is no need to adjust the angle between each mirror, and the adjustment mechanism is simplified or unnecessary. Productivity can be improved and production costs can be lowered.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a schematic diagram showing an embodiment of an optical reading device according to the present invention. In the figure, reference numerals 1 and 2 are conveyance rollers driven by a drive system (not shown), which rotate in the direction of the arrow in the figure. 3 and 4 are driven rollers arranged above the conveyance rollers 1 and 2, and are pressed by the respective rollers 1.2 with a predetermined pressure to rotate in the direction of the arrow, and P is the conveyance roller 1.
This document is sandwiched between the driven roller 3, the conveyance roller 2, and the driven roller 4, and is conveyed between the guide member 5 and the document table 6 in the direction of the arrow in the figure. Reference numeral 7 denotes a light source for illuminating the document P, and a fluorescent lamp or the like is used. Also, 8 is
It is a colorless and transparent document table glass, and is attached near the document reading surface of the document table 6.

On the other hand, one composite mirror according to the invention is designated by 10.

The composite mirror 10 is preferably formed by molding a plastic material such as polycarbonate. The composite mirror 10 includes a first reflecting mirror 11 and a second reflecting mirror 12. The first reflecting mirror 11 has a reflecting surface 13, and the second reflecting mirror 12 has one reflecting surface 14. The reflecting surface 12 and the reflecting surface 14 are made by coating the material surface of the composite mirror 10 with a metal film. be.

On the other hand, the first reflecting mirror 11 is provided with a transmission hole 15 through which the reflected light from the second reflecting mirror 12 passes.
The light passing through the transmission hole 15 passes through a lens 16 and forms an image on an imaging section 17 as a reading means. In this embodiment, the lens 16 and the imaging section 17 are also attached to a part of the compound mirror 10. It is being ' In the optical reading device having the above configuration, the light reflected from the original P is reflected by the first reflection mirror 11 and the second reflection mirror 12, and then reaches the imaging section 17 via the transmission hole 15. .

By providing a plurality of mirrors on the integrally molded body in this way, it is not necessary to adjust the angles of the reflecting mirrors 10 and 12, reducing the number of adjustment items and increasing productivity.

Next, FIG. 2 shows a second embodiment of the composite mirror of the optical reading device of the present invention. FIG. 2 shows a composite mirror 20. It consists of a reflecting mirror 21 and a second reflecting mirror 22. The reflective surfaces of the first reflective mirror 21 and the second reflective mirror are arranged to face each other. A transmission hole 2 is provided below the first reflection mirror 21 to transmit the reflected light from the second reflection mirror 22.
4 is provided. Also, the lens 16 is mounted on the mounting plate 23.
and an imaging section 17 are attached.

The light emitted from the light source 7 and reflected by the document P is reflected multiple times between the first reflection mirror 21 and the second reflection mirror 22 and passes through a predetermined optical path length.

The light passes through the transmission hole 24 of the first reflection mirror 21 and reaches the imaging section 17 via the lens 16.

In this embodiment, two parallel mirrors 21.2
2, the image light is sent to the mirror 21 three times, and the image light is sent three times to the mirror 22.
Although the composite mirror 20 is configured to reflect the light twice, the present invention is not limited thereto, and the number of reflections may be set to other values depending on the size of the device and the optical path length.

In this way, the relative angular accuracy and coordinate accuracy of the reflective mirrors 11.12 or 21°22 are determined within the composite mirror 10.20, which is one component, so the composite mirror 10.20
By paying attention only to the accuracy when combining with the main body or the lens 16, the imaging system 17, etc., it is possible to easily satisfy the required accuracy of the entire optical system.

(Effects of the Invention) According to the present invention, since the present invention has a composite mirror in which a plurality of mirrors are provided on an integrally molded body, the relative angles and coordinate accuracy of the reflecting mirrors are determined within one part, which makes it complicated. Since a detailed adjustment mechanism and adjustment work are not required, it is possible to provide an optical reading device with high productivity and low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an optical reading device according to the present invention, FIG. 2 is a partial vertical sectional view of a second embodiment of a composite mirror, and FIG. 3 is a schematic configuration diagram of a conventional optical reading device. It is a diagram. Explanation of symbols 1.2... Conveyance roller 3, 4... Driven roller 5
...Guide member 6...Document table 7...Light source 8...Document table glass 10...Compound mirror 11...First reflection mirror 12...Second reflection mirror 13.14・Reflection surface 15...Transmission hole
16... Lens 17... Imaging section

Claims (1)

[Claims] An optical reading device that reads an image of a document by focusing an optical image of the document on a reading means via a plurality of mirrors, characterized by having a composite mirror in which a plurality of mirrors are provided on an integral molded body. Optical reading device.