JP3440946B2 - Information reader - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading device, and is used, for example, in an information reading device for reading optical information (bar code, OCR, etc.) formed on a specularly reflecting surface (metal surface, etc.). It is a thing.

[0002]

2. Description of the Related Art Conventionally, the reading operation of a bar code reader used in a POS (Point Of Sales) system, which is a point-of-sale management system, is performed as described below.

That is, as shown in FIG. 2, which is an enlarged cross-sectional view of the bar code in the scanning direction, in the case where the bar code is printed on the paper surface, first, the bar 20 in the black portion and the space 21 in the white portion are removed. Irradiation light 200 is emitted from a light source (not shown) to the bar code.

Then, the irradiation light 200 incident on the bar 20
Shows diffuse reflection on the surface of the bar 20, but the reflectance of the black bar 20 is low, so that the light intensity of the reflected light imaged on the image sensor (for example, CCD) which is a photoelectric conversion element is extremely small. .

On the other hand, the reflected light incident on the space 21 is
Like the bar 20, it is diffusely reflected on the surface of the space 21, but
Since the white space 21 has a high reflectance, the light intensity of a part of the reflected light (reflected light 201) formed on the image sensor is higher than the reflected light from the surface of the bar 20. Therefore, the bar 20 and the space 21 can be identified by the difference in the light intensity of the reflected light received by the image sensor, whereby the information content of the bar code is read.

Further, the conventional bar code reader for performing the above-mentioned reading operation is further configured to deal with the following problems.

That is, when the surface of the bar code is covered with a colorless transparent film such as a laminate or vinyl, if the reflected light from the bar code imaged on the image sensor is the reflected light of the specular reflection component, the image sensor Then, there is a problem that the light intensity of the reflected light is too strong to cause halation and the barcode cannot be read.

Therefore, in the conventional bar code reader,
Even if the surface of the barcode is covered with a colorless transparent film as described above, it is possible to read, so that the reflected light of the specular reflection component from the barcode is not focused on the image sensor. Shape of hanging code reader,
The internal optical system is arranged so that the reflected light of the diffuse reflection component is imaged on the image sensor, so that the bar code is read by the reading operation.

[0009]

By the way, in recent years, a POS system having a bar code reader as described above,
With the widespread use of FA systems, bar codes have become metal products,
For example, direct marking on surgical scalpels (burning, etc.)
In order to perform centralized control using a bar code that has been marked (for example, in the case of surgical knife, how many days it has been sterilized and which has not been sterilized is managed using bar codes). There is a need for a reading device that can accurately read a bar code formed on a metal product.

However, in the above-mentioned conventional bar code reader, the reflected light of the specular reflection component from the bar code is not focused on the image sensor, and the reflected light of the diffuse reflection component is focused on the image sensor. Because
Even if you try to read a bar code formed on a surface (mirror surface, etc.) where the light intensity of the so-called specular reflection component increases, such as metal products, the light intensity of the reflected light of the diffuse reflection component is too weak. There is a problem that the bar code cannot be read by a normal read operation of placing the bar code in contact with the bar code forming surface and reading the bar code, which is troublesome.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an information reading device capable of simplifying the reading operation.

[0012]

Therefore, in the invention according to the first aspect, a housing having a reading port, an irradiation means for irradiating optical information with light provided in the housing, and the housing are provided in the housing. Is provided, receives the reflected light of the specular reflection component from the optical information, and diffuses and reflects it.
After, it is reflected by a light diffuse reflection means for irradiating again the optical information, the provided within the housing, the reflected light and the light diffuse reflection means of the diffuse reflection component from the optical information wherein An information reading device comprising: a reading unit that receives reflected light of a specular reflection component from the optical information that is reflected again by the optical information and reads the information content of the optical information. It is a thing.

Therefore, when reading optical information formed on a so-called irregularly reflecting surface such as paper, the information content of the optical information can be read based on the reflected light of the diffuse reflection component from the optical information, For example, when reading optical information formed on a surface in which the light intensity of the specular reflection component of the reflection components of the reflected light emitted when light is incident is higher than the light intensity of one diffuse reflection component. The light spread
When the reflected light of the specular reflection component from the optical information reflected by the diffuse reflection means can be received and the information content of the optical information can be read, in which surface the optical information is formed However, it has an excellent effect that the information can be read by one information reading device and the reading operation is simplified.

[0014]

[0015]

[0016]

[0017]

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on an embodiment shown in the drawings.

In this embodiment, a case where the present invention is applied to a handy type bar code reader will be described.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, showing a cross section in the longitudinal direction of a bar code.

In FIG. 1, a bar code reader B in this embodiment is mainly composed of a hound jig 40 having a reading port 40a, an illumination light source 1 for irradiating light, and light within a predetermined range (irradiating only a diffuse reflection plate 3). The lens 2 is configured to condense in a range), the diffuse reflection plate 9 that diffuses and reflects the incident light, the flat reflecting mirror 5, the lens 6 provided in the lens barrel 7, and the image sensor 8.

A bar code (for convenience, the space of the bar code, that is, only the mirror surface is drawn in the drawing) is printed on the mirror surface 4, and the light incident on the mirror surface 4 is specularly reflected (the incident light is at an angle equal to the incident angle). And is reflected at an angle opposite to the incident angle). Note that, in FIG. 1, the mirror surface 4a is depicted as being tilted at an angle β with respect to the mirror surface 4 in the drawing preparation, but in reality, the barcode reader itself is tilted at an angle β with respect to the mirror surface 4. Is meant,
Also in the following description, it is assumed that the barcode reader is tilted by the angle β with respect to the mirror surface 4.

The electric signal output from the image sensor 8 is, as shown in FIG.
The signal is amplified and binarized by 1 and decoded by the CPU 33, and then output to the external device 35 via the interface circuit 34. The CPU 33 outputs a drive signal to the sensor drive circuit 30 and the LED drive circuit 32, so that the image sensor 8 and the illumination light source 1 are provided.
To drive.

Next, the operation of the above configuration will be briefly described.

In FIG. 1, when light is emitted from the illumination light source 1, the emitted light is radially dispersed by the lens 2 and reaches the mirror surface 4. Then, the irradiation lights 110 and 114 that have reached the mirror surface 4 are specularly reflected on the surface of the mirror surface 4 and reach the diffuse reflection plate 9 as specular reflected light 111 and are diffused and reflected. The diffuse reflection light 112, which is a part of the specular reflection light 111 obtained by the diffuse reflection of the specular reflection light 111, reaches the specular surface 4 again, and is specularly reflected again by the specular surface 4 to become diffuse / specular reflection light 113.

The direction of travel of the diffused / specular reflected light 113 is changed to the lens 6 of the lens barrel 7 by the plane reflecting mirror 5, and the lens 6 forms an image on the image sensor 8 and converts it into an electric signal. It Therefore, like the conventional bar code, if the reflected light is not received, it can be determined that the irradiation light is incident on the bar, and if the reflected light is received, it can be determined that the irradiation light is incident on the space. The information content of the bar code is read based on the signal.

On the other hand, when the bar code reader B is tilted by the angle β, the specular reflected light 115 emitted through the lens 2 and the mirror surface 4a is diffusely reflected and the specular reflected light 11 is obtained.
Diffuse reflected light 116 which is a part of 5 reaches the mirror surface 4 again, and is again specularly reflected by the mirror surface 4a to become diffused / specular reflected light 113, which reaches the image sensor 8 by following the above-mentioned optical path. The information content of the barcode is read.

As described above, in the bar code reader B in this embodiment, when reading a bar code formed on a so-called irregularly reflecting surface such as a paper surface, based on the reflected light of the diffuse reflection component from the bar code. The information content can be read, and when reading a barcode formed on a mirror surface, the reflected light of the specular reflection component from the barcode reflected by the diffuse reflection plate 9 is received and reflected again on the barcode. Since it reaches the image sensor 8 even if the barcode formed on any surface can be read by one barcode reader, there is an excellent effect that the reading operation is simplified. is there.

In the bar code reader B of this embodiment, the specular reflection light from the specular surface 4 is diffused and reflected by the diffuse reflection plate 3 by utilizing the property of specular reflection of the specular surface 4 on which the bar code is printed. Then, the light is made incident on the mirror surface 4 again, and thereby an optical path for forming an image on the image sensor 8 is obtained. Therefore, the mirror surface 4 is used as a reflecting mirror similar to the plane reflecting mirror 5.

This is a possible method (the surface may be subjected to a satin treatment, which will be described later) because the printed surface of the bar code is a mirror surface. In other words, even if the light is reflected multiple times, since the light absorption rate is low (that is, the reflectance is high) with a mirror-like surface, the light intensity is greatly reduced and unreadable (when the light intensity is weak, This is because it is recognized as a bar instead of a space).

Further, at the time of reading operation, the bar code reader B
Since the reflected light from the bar code can be accurately focused on the image sensor 8 even when the bar code is tilted with respect to the mirror surface 4, it is not necessary to adjust the incident angle to the bar code and the bar code reader B The operation of can be performed easily.

In this embodiment, the irradiation light on the mirror surface 4 may be parallel light such as a laser, in addition to the radial irradiation light described above.

Next, another embodiment will be described.

In the above embodiment, the incident light on the mirror surface 4 (including the light to be re-incident on the mirror surface) uses diffused light, but the light enters at different incident angles when viewed from a predetermined position on the bar code. If so, parallel light from a laser or the like may be used.

Further, in the above-mentioned one embodiment, the case where the present invention is applied to the device for reading the bar code is explained, but the present invention is applied to the device for reading the optical information (OCR, two-dimensional code, etc.) other than the bar code. The invention may be applied.

Further, in the above-mentioned one embodiment, the bar code is printed on the mirror surface, but of the reflection components of the reflected light emitted when the light is incident, the regular reflection component (the reflection angle of the reflected light is incident). Light intensity of component equal to angle) is one diffuse reflection component (component reflected in a direction other than the specular reflection direction)
The present invention may be applied to an apparatus for reading optical information formed on a forming surface whose light intensity is higher than that of the above. As an example thereof, there is a bar code reader that reads a bar code on a surface that has undergone a satin finish or a hairline finish.

Further, the diffuse reflection plate in the above-mentioned embodiment,
Or, the size of the member, the installation angle, etc.
The shape and the like are set so that when viewed from the image sensor 8 side, the bar code is reflected around the barcode on the mirror surface 4 that is mirror-reflected. The color of the diffuse reflector is preferably white, which reflects the color of the irradiation light as it is, or the same color as the irradiation light (generally red).

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view for explaining a conventional principle of reading a barcode when a barcode is printed on the paper surface.

FIG. 3 is an explanatory diagram for explaining a conventional reading principle when a barcode is printed on a metal surface.

FIG. 4 is an explanatory diagram for explaining a conventional reading principle using diffused light when a barcode is printed on a metal surface.

FIG. 5 is a schematic configuration diagram for explaining an electrical configuration of the bar code reader in the one embodiment.

[Explanation of symbols]

1 Illumination light source 9 Diffuse reflector 40 housing 40a reading port

Claims (2)

(57) [Claims] 1. A housing having a reading port, an irradiation unit provided in the housing for irradiating optical information with light, and a reflection light of a specular reflection component from the optical information provided in the housing. After receiving and diffusing reflection,
A light diffuse reflection means for irradiating the serial optical information, provided in the housing, reflected by the reflection light and the light diffuse reflection means of the diffuse reflection component from the optical information
An information reading device comprising: a reading unit that receives the reflected light of the specular reflection component from the optical information that has been reflected by the optical information again and reads the information content of the optical information. . 2. The light diffusing / reflecting means is near the reading port.
The information reading device according to claim 1, wherein the information reading device is provided adjacent to the information reading device.