JPS6225561A - Photoelectric conversion mechanism - Google Patents

Abstract

PURPOSE:To select a light of wavelength suitable for the surface of a paper by switching the light source by providing optical filters to make a reflecting light prescribed characteristics between the light source and the surface of the paper and between the latter and an optical lens. CONSTITUTION:Between the light sources A2, B3 and the paper and the likes 1, and between the latter and the optical lens 5, filters 10-12 to block the transmitting lights are fixed. The lights from the source A2 always pass through the filters 10 and 11, and the lights from the source B3 always pass through the filter 12 and a photodetecting sensor 6 whose optical characteristic is so set. Then, a prescribed spectral characteristic is obtained. Accordingly, it is wade possible to read with the light of the wavelength suitable for the paper and the likes 1 to read, by which the accuracy of reading is improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a photoelectric conversion mechanism for an optical information reading device, and in particular to a photoelectric conversion mechanism suitable for extracting light of a wavelength suitable for the writing method on paper sheets to be read. It is about the mechanism.

Background of C invention] Conventionally, OCR (○pLical Character
When reading information optically using devices such as r Reader) or facsimile devices, the light from the light source has a wavelength of 900 nm.
If the wavelength is close to 600nm, it will not be possible to read characters or marks written with a ballpoint pen, etc. If the wavelength is around 600nm, dropout colors such as blue or green will also be read, so please check the type or color of the characters or marks to be read. The wavelength of the light used for reading is switched by

As a method of switching, there is a method of selecting the wavelength of the reflected light from the @ tag and sending it to the light receiving element through a filter, as described in Japanese Patent Application Laid-Open No. 56-82983. This requires a certain amount of space because it is performed mechanically using a power source such as a motor, which limits the ability to miniaturize the device.

Furthermore, as described in Japanese Patent Application Laid-Open No. 182784/1984, there is a method in which light sources emitting wavelengths for different types of dropout colors and different types of information writing means are provided in advance and the light sources are switched.

This is because the wavelength characteristics of the light source cannot be freely selected.

In practical terms, when trying to read lightly written letters and marks, it also read dropout colors in dark areas.

[Purpose of the invention]

The purpose of the present invention is to solve such conventional problems and to provide an information reading device that optically reads characters, marks, etc. written on paper, with high reading accuracy and easy operation using a simple and inexpensive method. An object of the present invention is to provide a photoelectric conversion mechanism that can be miniaturized.

[Summary of the invention]

In order to achieve the above object, the photoelectric conversion mechanism of the present invention includes a plurality of light sources that irradiate light onto one sheet of paper, and an optical lens that focuses reflected light from the sheet of paper onto a photoelectric conversion element. In an information reading device that reads characters, marks, etc. written above, optical filters (optical color glass filters 0, 11, 12) that make the reflected light have predetermined wavelength characteristics are connected to the plurality of light sources (light sources A2, 11, 12). light gB3) and paper (sheets 1
) and between the paper surface (paper sheet 1) and the optical lens (5).

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a photoelectric conversion mechanism showing an embodiment of the present invention. In the figure, 1 is a paper sheet such as @ vote, 2
, 3 are light sources A and B that emit irradiation light, 4.7 is a reflecting mirror, 5
is an optical lens that focuses the reflected light on the light receiving sensor 6; 8 is an arrow pointing in the conveying direction of the paper sheet 1; 9 is a guide material that guides the conveyance of the paper sheet 1; and 10 to 12 are optically colored glass filters. be.

Further, in the structure, 21 is a filter l.

22 is a member that fixes the filter 12 in front of the light source B3, 23 is a housing that supports the optical lens 5 and the light receiving sensor 6, and 24 is the filter 11.
25 is a base that supports the reflecting mirror 4, each member 21, 22, 24, and the housing 23 to support the mechanism as a whole; , 26b.

The photoelectric conversion mechanism irradiates the light gA2 or the light source B3 with the light onto a sheet of paper, reflects the reflected light from the paper surface at 90 degrees on the reflecting mirror 4, and converts the light into the The reflected light is focused and imaged on a light receiving sensor 6 by an optical lens 5, and based on the image, the light receiving sensor 6 converts from an optical level to an electrical level, thereby generating a black and white signal, that is, a dotted line on the paper surface of one paper sheet 1. A reading signal of the paper sheet 1 read by the optical path is output.

However, since the light from the light @A2 cannot be directly irradiated onto the paper surface, it is performed via the first reflecting mirror 7.

This is because the guide member 9 for reliably conveying the paper sheet 1 in the direction of the arrow 8 has a convex shape, and the convex portion blocks the light source A2 and the paper sheet 1.

Next, a method for selecting the wavelength of reading light in the photoelectric conversion mechanism will be described with reference to FIG.

This figure shows the wavelength characteristics, and curves 13 and 14 in the figure
are light source A2. The energy distribution 1 curves 15, 16 and 18, 19 of the light source B3 are respectively filtered by the filter 10. Filter 11. Optical (transmittance) of filter 12 light receiving sensor 6
Characteristics, hatched areas 17 and 20 are light source A2. Light source B3
This is the read light energy distribution at .

When using the light source A2, the photoelectric conversion mechanism reads the paper sheet 1 with light having a wavelength of around 600 nm by passing the light through the filter 10→(on the page)→filter 11. That is, as shown in FIG. 2, first, curve 15
A filter 10 having a curve 16 cuts the long wavelength side of the light from the light source A2 and irradiates it onto the paper surface.Then, from the reflected light, a filter 11 having a curve 16 cuts the short wavelength side. is sent to the light receiving sensor 6.

On the other hand, when using the light source B3, the light is transmitted through the filter 12 → (on the page) → the light receiving sensor 6, and the paper sheet l is read with light having a wavelength of around 72 Onm, as described above. That is, as shown in FIG. 2, first, curve 1
The short wavelength side is cut from the light from the light source A2 using a filter 12 with a filter 12 having a filter 8, and the short wavelength side is cut off and irradiated onto the paper surface.
The long wavelength side is cut by the light receiving sensor 6 having a shape, and the light in the shaded area 20 is finally sent to the light receiving sensor 6.

Next, a method of switching the light source A2 or light source B3 described above will be described with reference to FIG.

In the figure, 27 is a light source A2. A light fX selection unit instructs to turn on/9 lights of B3, 28 is a lighting device 29a of light source A2
, is a drive circuit that turns on or off the light source 29b of the light source B3. Note that although the light g selection section 27 and the drive circuit 28 are not shown, they are mounted within the device. In addition, the light g selection section 27
The light source is selected using the JOB number, ID number, etc. provided on the paper sheet 1.

), e7.7□1. a. □4.1, E, □2゜ selects the light source most suitable for the paper sheet 1, and based on the content, the drive circuit 28 turns on either the lighting device A 29 or the lighting device B 29, and turns off both lights. , outputs a read signal according to the state.

In this way, for the light from the light source A2, the filters 10 and 1
1 has a structure that always transmits the optical characteristics of the filter 12 and the light receiving sensor 6 for the light from one light source B3, and by obtaining predetermined spectral characteristics, the light source A2 or B
Just switch 3 to read the paper sheet 1! ! It becomes possible to read the information using light with a wavelength of 2. Further, since a filter moving mechanism is not required, the structure is inexpensive and compact, and the present apparatus can be downsized together with the present mechanism.

In this example, a filter lO~1 made by a vapor deposition method is used.
2 as an optical lens 5. By removing the filter 11 in front of the optical lens 5 and installing a special filter 31 made by the same vapor deposition method in front of the light 119f2.3, as shown in FIG. A conceivable method is to make the reflected light 34 from the paper sheet 1 have the energy distribution wavelength of the shaded area 17, 20 in FIG. However, this special filter 31 needs to satisfy wavelength characteristics in all directions of the light sources 2 and 3, and its manufacture is technically difficult. Specifically, the purpose is to satisfy the wavelength characteristics of the straight light 32 and oblique light 33 that are irradiated from the light source 2°3 to the point C on the paper sheet 1, and the light sources 2 and 3 are fluorescent lamps, etc. In the case of an extremely long cylindrical shape, it is impossible to manufacture an optical filter 31 using a vapor deposition method that satisfies the characteristics of filters 10 to 12 even for light emitted obliquely.

〔Effect of the invention〕

As described above, according to the present invention, in the information reading device that optically reads characters, marks, etc. written on paper, the light source A2. A filter for blocking transmitted light is fixed between B3 and the paper sheet 1 and between the paper sheet 1 and the optical lens 5,
Light source A2. Obtaining a steeper energy distribution than B3, the light
By switching gA2.83, it is possible to select light of a wavelength suitable for the paper sheet 1, thereby further improving reading accuracy. Furthermore, since a mechanism for mechanically moving the filter is not required, the single device can be simplified and miniaturized.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a photoelectric conversion mechanism illustrating an embodiment of the present invention, Fig. 2 is a wavelength characteristic diagram for explaining the wavelength selection method, and Fig. 3 is a diagram showing the switching method of the light 1111XA, H. FIG. 4 is a block diagram showing a part of a photoelectric conversion mechanism for explaining another embodiment of the present invention. 1: paper sheets, 2: light source A, 3: light source B, 4, 7: reflecting mirror, 5: optical lens, 6: light receiving sensor, 8: transport direction of paper sheets, 9 guide material, to-12° 31: Filter, 1
3, 14: Energy distribution curves of light sources A and B, 15, 1
6.18: Optical (transmittance) of filters lO, 11, 12
Characteristic curve, 19: Optical (transmittance) characteristic curve of light receiving sensor 6, 17, 20: Shaded area (energy distribution of light MA, B according to the present invention), 21, 22. 24: Member, 23: Housing, 25: Base, 26a, 26b: cutout hole, 2
7: light source selection section, 28: drive circuit, 29a, 29b = lighting devices A, B, 32: straight light, 33: diagonal light.

Claims (1)

[Claims] (1) Information that includes multiple light sources that irradiate light onto a paper surface and an optical lens that focuses reflected light from the paper surface onto a photoelectric conversion element, and reads characters, marks, etc. written on the paper surface. A photoelectric conversion mechanism in a reading device, wherein an optical filter that makes the reflected light have a predetermined wavelength characteristic is provided between the plurality of light sources and the paper surface and between the paper surface and the optical lens.