JP3127847B2 - 2D code reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code reader, and more particularly to a two-dimensional code reader.

[0002]

2. Description of the Related Art In recent years, most products sold at supermarkets, convenience stores, retail stores, and the like have a label printed with a barcode (one-dimensional code) composed of white and black stripes attached thereto. Or they print directly. This barcode is read by a barcode reader (scanner), and the data obtained by reading the barcode can be used for sales and inventory management, ordering, and purchasing operations. Started to be introduced. In addition, bar codes are also OA, F
A. It is widely used for medical-related, libraries, courier services, etc.
It was introduced for streamlining.

However, since this type of bar code (one-dimensional code) has white and black stripes printed in the length direction of the label, it is necessary to increase the length of the label in order to increase the amount of information. Occurs. Increasing the length of the label will make the label larger, for example, glasses, precious metals,
There is also a problem that it is difficult to use small articles such as IC chips and articles such as a printed circuit board which cannot secure a sufficient space for attaching a label. In addition, when the label becomes large, a barcode reader (scanner) for reading a barcode printed on the large label also becomes large.

Therefore, a two-dimensional code having the same amount of information as the above-described conventional bar code (one-dimensional code) and reducing the area or increasing the amount of information with the same area has been proposed. became. The two-dimensional code is roughly classified into two types, a stack type code and a matrix type code. The stack type code is a code in which information is displayed vertically and horizontally by stacking one-dimensional codes vertically, and the matrix type code alternates black and white information. This is a code displayed in a vertical and horizontal mosaic pattern at the crosses (cells).

As one of the matrix type codes, for example, a two-dimensional code as illustrated in FIG. 9 is known. The two-dimensional code shown in FIG. 9 is composed of a cutout symbol a and a data area c composed of black and white cells b arranged in the up, down, left and right directions, and is configured to be capable of high-speed reading from any direction of 360 degrees. Things. The black-and-white square cell b of this two-dimensional code is at least 21 ×
It consists of 21 symbols and has a maximum of 177 × 177 symbols, and the inner cutout symbol 1 is composed of 8 × 8 cells. Various types of two-dimensional codes other than those illustrated in FIG. 9, such as maxi codes, veri codes, and data codes, have been proposed.

For this reason, the two-dimensional code illustrated in FIG. 9 can handle all kinds of data such as numerals, alphabets, symbols, kanji, kana, and control codes, and the data amount is up to seven.
It can represent up to 366 characters (numbers) and can be represented in about 1/10 the area of conventional barcodes (one-dimensional codes), reducing paper and label sizes, and reducing paper costs. Is possible.

This two-dimensional code reading device (scanner)
As shown in FIG. 10, a head unit H that converts optical information of a two-dimensional code into a time-series electric signal, and converts the electric signal converted by the head unit H into character data (code data) corresponding to the two-dimensional code. 2. Description of the Related Art A separation type scanner is known which is electrically connected to a decoding unit D which decodes and outputs the result by a connection code C.

FIG. 11 is a view showing a part of a head portion H of the separation type scanner. In a casing 1 of the head portion H, a label (two-dimensional code label) L _C on which a two-dimensional code is printed is provided. Light sources 2a and 2b for irradiating light;
A lens (optical system) that receives the reflected light of the light applied to the two-dimensional code label L _C from the a and 2b as two-dimensional optical information and forms an image on the light receiving surface of a CCD image sensor that converts the reflected light into a time-series electric signal. 3). Provided also in the reading tip side casing 1, the dust, to dust or the like is prevented from entering into the casing 1, in a square shape as transparent dustproof plate 4 faces the two-dimensional code label L _C Have been.

[0009] The CCD image sensor comprises a light source 2a,
2b is provided with a sensor unit by a photodiode array having a spectral sensitivity peak region near the emission spectrum of the red light emitting diode used for 2b, a charge storage unit and a charge readout unit, and the sensor unit becomes a light receiving surface of a CCD image sensor. . When the light reflected by the two-dimensional code label L _C forms an image on the sensor unit on the light receiving surface, a time-series electric signal is output from the charge readout unit, and the electric signal is amplified by an amplifier circuit and then binarized. The electric signal amplified by the circuit is converted into a binary signal. The decoding unit decodes the binary signal into character data (code data) corresponding to a two-dimensional code.

[0010]

By the way, the two-dimensional code label L _C printed on the two-dimensional code label L _C by the head H described above is used.
When reading a two-dimensional code, the reading tip side of the casing 1 is parallel to the two-dimensional code label L _C and the reading tip side is pressed against the two-dimensional code label L _C. The optical axes will be close.

[0011] Thus, for example, light irradiated to the two-dimensional code label L _C from the light source 2a is a two-dimensional code label L _C
Is specularly reflected (specular reflection) at the point α, enters the lens 3 of the optical system, and the light emitted from the light source 2b to the two-dimensional code label L _C is specularly reflected (positive reflection) at the β point of the two-dimensional code label L _C Since the light is reflected (reflected) and enters the lens 3 of the optical system, a problem arises in that the two-dimensional code cannot be read accurately. Further, the light emitted from the light source 2a is specularly reflected (specular reflection) at the γ point of the dustproof plate 4 and is incident on the lens 3 of the optical system.
Since the light emitted from b is specularly reflected (specularly reflected) at the point δ of the dust-proof plate 4 and enters the lens 3 of the optical system, a problem arises that obstructs reading of the two-dimensional code.

On the other hand, if the light emitting unit is arranged so that the direction of the light emitting unit is on the opposite side to the reading front end and is illuminated by indirect illumination, the above-described specular reflection (specular reflection) can be prevented. Although it is possible, the use of indirect illumination also causes a problem that the amount of light irradiated on the two-dimensional code label is reduced and the reading performance is reduced. In view of the above, the present invention has been made in view of the above problem, and it is possible to prevent specular reflection (specular reflection) on a two-dimensional code label without reducing the amount of light irradiated on the two-dimensional code label. It is to make.

[0013]

According to the present invention, in order to solve the above-mentioned problems, according to the first aspect of the present invention, light irradiated onto a two-dimensional code from the light source near the light source is specularly reflected (reflected). (Specular reflection) and located on the optical path that enters the optical system
Scatters light emitted from the same light source only at the site
The member provided with the means is arranged. Thus, when a member provided with means for scattering the light emitted from the light source is arranged, even if the light is irradiated on the two-dimensional code from the light source, the reflected light directly enters the optical system as specular reflected light. Therefore, the two-dimensional code can be read accurately, and the reading efficiency of this type of reading device is improved. Also, since only the portion where the light scattering member is disposed only scatters the light emitted from the light source, the light emitted from the light source can be efficiently placed on the two-dimensional code without reducing the light amount.
Ku will be illuminated, without causing reading disorder,
The two-dimensional code can be read accurately.

According to the second aspect of the present invention, a transparent dust-proof plate, which is provided to prevent dust and dirt from entering the two-dimensional code reader, is located on the light path on the light source side surface. A means for scattering the light emitted from the light source is provided only at the portion where the light is emitted. By doing so, it is possible to prevent light emitted from the light source from directly entering the optical system as specular reflected light without providing a new member, and it is possible to provide this kind of scattering means simply and inexpensively. Will be possible.

According to the third aspect of the present invention, a portion located on the optical path on the light source side surface of the transparent dustproof plate.
Since the light emitted from the light source is scattered by providing irregularities that scatter light only at the position, it is necessary to provide this kind of light scattering means simply by forming irregularities on the surface of the dustproof plate on the light source side. This makes it possible to easily and inexpensively manufacture a two-dimensional code reader capable of accurately reading a two-dimensional code.

According to a fourth aspect of the present invention, a portion of the transparent dustproof plate located on the light path on the light source side surface.
Since a means for scattering light emitted from the light source by performing silk-screen printing for scattering light only in position simply silk printing on the light source-side surface of the dust-proof plate
This type of light scattering means can be provided simply by applying , and a two-dimensional code reader capable of accurately reading a two-dimensional code can be easily and inexpensively manufactured.

According to the fifth aspect of the present invention, a portion of the transparent dustproof plate located on the light path on the light source side surface.
It is a means to scatter the light emitted from the light source by providing unevenness that scatters light only at the position and applying silk printing that further scatters light on this unevenness, so that the light emitted from the light source is It becomes scattered doubly on the top. Such double scattering improves the scattering effect and further improves the reading accuracy.

[0018] In the invention of claim 6 is provided with a vertically shielding plate of a transparent the dustproof plate on the side of the light source. When such a light-shielding plate is provided, even if light emitted from the light source is specularly reflected by the dust-proof plate, the specularly reflected light is blocked by the light-shielding plate. It will not be incident. Therefore, the effect of specular reflection light on the dust-proof plate can be prevented.
Obstacles in reading the dimensional code can be eliminated.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a two-dimensional code reader according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a head unit of a handy type two-dimensional code reader (scanner) of the present embodiment, and FIG.
FIG. 1B is a front view, and FIG.
(C) is a side view thereof. Further, FIG.
3 is a cross-sectional view taken along line BB of FIG. 1B, and FIG. 4 is an enlarged view of a main part of FIG. 1B.

The two-dimensional code reader (scanner) of the present embodiment has a casing 10, and a reading port 11 faces a two-dimensional code at a reading tip side of a bent portion 10a of the casing 10. It is formed in a rectangular shape.
Inside the casing 10, a dustproof plate 20, a light source 3
0, a mirror 40, an imaging lens 50, a CCD image sensor 60, and a light shielding plate 70 are provided.

The dust-proof plate 20 is made of a transparent resin, and dust, dust, etc., from the leading end of the reading plate,
To prevent intrusion. Light emitted from the light source 30 of the dust-proof plate 20 onto the two-dimensional code passes through the dust-proof plate 20 and is specularly reflected (specular reflection) on the two-dimensional code.
Diffusion members 21 for diffusing the light emitted from the light source 30 are disposed at four positions on the optical path that enters the imaging lens 50 via the mirror 40. As shown in FIG. 4, the diffusion member 21 is connected to the light source 3 of the dustproof plate 20.
The surface on the 0 side is subjected to graining (processing for forming irregularities) 21a, and silk printing 21b is given on the graining 21a.

The light source 30 is composed of a red light emitting diode that emits red light, and four red light emitting diodes are arranged at predetermined positions in the casing 10, and the red light emitting diodes are arranged in accordance with instructions from a control circuit 140 (see FIG. 5). The drive circuit is driven to emit red light on a two-dimensional code label on which a two-dimensional code (not shown) is printed.

The mirror 40 is provided to change the direction of light emitted from the light source 30 onto the two-dimensional code label and reflected on the two-dimensional code label and incident on the casing 10. The imaging lens 50 transmits the incident light whose direction has been changed by the mirror 40 to the CCD image sensor 60.
Is provided to form an image on the light receiving surface of the light emitting element. Here, the mirror 40 and the imaging lens 50 constitute an optical system.

The CCD image sensor 60 includes a sensor unit including a photodiode array having a spectral sensitivity peak region near the emission spectrum of the red light emitting diode used as the light source 30, a charge storage unit, and a charge readout unit. The area size is 1/3 inch and the number of effective pixels is 330,000. Sensor part is CCD
It becomes the light receiving surface of the image sensor 60. Then, based on a command from the control circuit 140 (see FIG. 5), the sensor driving circuit is driven, and the light reflected on the two-dimensional code label and incident on the casing 10 forms an image on the sensor portion on the light receiving surface. In this case, a time-series electric signal is output from the charge reading unit.

The light-shielding plate 70 is formed of a black synthetic resin plate. The light-shielding plate 70 is provided to prevent light emitted from each light source 30 from being reflected by the dust-proof plate 20 and entering the imaging lens 50. It is disposed on the side of each light source 30 above the dustproof plate 20.

FIG. 5 is a block diagram showing a block configuration of the head unit 100 and the decoding unit 200. The head unit 100 of this separation type scanner has a light source 30 for irradiating a two-dimensional code with light, An optical system 110 including a mirror 40 and an imaging lens 50 for irradiating light on a two-dimensional code and receiving the reflected light as two-dimensional optical information (image data), and the two-dimensional light received by the optical system 110 A CCD image sensor 60 for converting the optical information of the CCD into a time-series electric signal, an amplification circuit 120 for amplifying the time-series electric signal converted by the CCD image sensor 60, and an electric signal amplified by the amplification circuit 120. A binarizing circuit 130 for converting the signal into a binarized signal; a control circuit for controlling the operations of the light source 30, the CCD image sensor 60, the amplifying circuit 120 and the binarizing circuit 130. Consisting of 140 Metropolitan.

The control circuit 140 is constituted by a well-known microcomputer, and recognizes that a trigger switch (not shown) provided on the head unit 100 is pressed, and sends a drive command to a drive circuit of the light source 30 to transmit the drive command. And emits a drive command to the sensor drive circuit of the CCD image sensor 60 to make the photoelectric conversion unit by the photodiode array receive light.
The control circuit 140 sends an amplification command for sequentially amplifying a time-series electric signal output from the charge reading unit of the CCD image sensor 60 based on a gain set in the amplification circuit 120 in advance. 120
The binarizing circuit 130 transmits a binarizing command signal to the binarizing circuit 130 in order to sequentially binarize the time-series electric signal amplified by the above.

On the other hand, the decoding section 200 includes a decoding circuit (decoding circuit) 210 for decoding the electric signal converted by the head section 100 into character data (code data) corresponding to a two-dimensional code.

Next, the reading operation of the two-dimensional code reader of the present embodiment configured as described above will be described with reference to FIGS. First, when a trigger switch (not shown) of the head unit 100 is turned on, the control circuit 140
0 is transmitted to the drive circuit of the light source 30, and the light source 3
0 is emitted for a predetermined time (for example, 5 seconds), and red light is irradiated on the label on which the two-dimensional code is printed. Next, the control circuit 140 sends a drive command to the sensor drive circuit to bring the CCD image sensor 60 into a drive state.

At this time, the light emitted from each of the light sources 30 is diffused by the diffusion members 21 provided at the four positions on the light source 30 side of the dustproof plate 20 and having been subjected to the grain processing 21a and the silk printing 21b. For this reason, it is possible to prevent specularly reflected light, which is specularly reflected on the label on which the two-dimensional code is printed, from directly entering the imaging lens 50. Further, light reflected on the surface of the dust-proof plate 20 is blocked by the light-shielding plate 70, so that it does not directly enter the imaging lens 50. The light diffused by the diffusion member 21 of the dust-proof plate 20 or the light directly incident on the dust-proof plate 20 passes through the dust-proof plate 20 and is irradiated on the label on which the two-dimensional code is printed.

As a result, red light is emitted from the light source 30 onto the label on which the two-dimensional code is printed, and the diffusion member 21 is provided at four positions on the light source 30 side of the dust-proof plate 20. Therefore, the specularly reflected light (specular reflection) on the label on which the two-dimensional code is printed does not directly enter the imaging lens 50. Therefore, the reflected light from the label on which the two-dimensional code is printed is reflected by the mirror 40 while the reflected light other than the specular reflection (specular reflection) light is diffused, and is incident on the imaging lens 50.

The reflected light incident on the imaging lens 50 is
The light passes through the imaging lens 50 and forms an image on the light receiving surface of the CCD image sensor 60, that is, the sensor unit. When the CCD image sensor 60 receives the reflected light from the label on which the two-dimensional code is printed, the charge readout portion of the CCD image sensor 60 operates when the two-dimensional code corresponds to the white / black cell b (see FIG. 9). It sequentially outputs a series of electric signals. Then, the amplification circuit 120 sequentially amplifies the time-series electric signals output from the CCD image sensor 60 based on the predetermined gain, and sequentially outputs the amplified signals to the binarization circuit 130. Then, the binarization circuit 130 sequentially converts the amplified signal amplified by the amplifier circuit 120 into a binary signal, and sequentially
The binary signal is sent to a decoding circuit (decoding circuit) 210 of the decoding unit 200.

A decoding circuit (decoding circuit) of the decoding section 200
210 receives the binarized signal output from the amplifier circuit 120 and decodes it into character data according to a two-dimensional code. Decoding circuit (decoding circuit) 2 of decoding section 200
When the decoding of the character data is successful, the decoding circuit (decoding circuit) 210 sends the decoded character data to a register or a central processing unit (not shown). I do. As a result, the control circuit 140 sends a drive stop signal to the image drive circuit of the CCD image sensor 60 to stop the drive, and also sends a drive stop signal to the amplifier circuit 120 and the binarization circuit 130 to amplify the signal. The driving of the circuit 120 and the binarization circuit 130 is stopped to terminate the reading operation.

As described above, in the present embodiment ,
Light emitted from the light source 30 on the two-dimensional code is transmitted through the dust-proof plate 20, the fourth optical path incident on the specular reflection (regular reflection) by the imaging lens 50 via the mirror 40 on the two-dimensional code Since the diffusing member 21 on which the grain processing (processing for forming unevenness) 21a and the silk printing 21b are performed is disposed at the location, the reflected light of the light emitted from the light source 30 onto the two-dimensional code is The light does not directly enter the optical system as specular reflected light. Therefore, the two-dimensional code can be read accurately, and the reading efficiency of this type of reading device is improved. In addition, since the diffusion member 21 is disposed only at four positions on the optical path that is specularly reflected (specular reflection) on the two-dimensional code and enters the imaging lens 50 via the mirror 40, the light is emitted from the light source 30. The two-dimensional code is radiated onto the two-dimensional code without lowering the light quantity of the light, so that the two-dimensional code can be read accurately without causing a reading trouble.

Since the transparent dust-proof plate 20 is originally provided to prevent dust and dirt from entering the casing 10, creasing (processing for forming irregularities) 21a is performed at four places. By simply applying the silk printing 21b, the light emitted from the light source 30 can be prevented from directly entering the optical system as specular reflected light without providing a new member. Means can be provided. Further, since the silk printing 21b is performed on the grain processing 21a, the emitted light from the light source 30 is scattered by the grain processing 21a and the silk printing 21b. Such double scattering improves the scattering effect and further improves the reading accuracy.

Further, since the light shielding plate 70 is provided on the side of the light source 30 vertically from the transparent dustproof plate 20, even if the light emitted from the light source 30 is specularly reflected by the dustproof plate 20, this specular reflection is performed. The light is blocked by the light shielding plate 70, so that the specularly reflected light does not directly enter the optical system. Therefore, the effect of the specular reflection light on the dust-proof plate 20 can be prevented, and the obstruction of reading the two-dimensional code can be eliminated.

Modifications As described above, in the two-dimensional code reader of the present embodiment, an example in which the present invention is applied to a handy type two-dimensional code reader (scanner) has been described. Can be applied to the two-dimensional code reader (scanner). 6A and 6B are diagrams showing a schematic configuration of a head portion of a pen-type two-dimensional code reader (scanner) according to the present modified example, FIG. 6A is a front view, and FIG.
6 is a bottom view, and FIG. 6C is a side view thereof.
FIG. 7 is a cross-sectional view taken along the line DD of FIG.
FIG. 7 is an enlarged view of a main part of FIG.

The pen type two-dimensional code reader (scanner) of this modification has a casing 300, and a reading port 31 is provided at a reading tip side 310 of the casing 300.
1 is formed in a rectangular shape so as to face the two-dimensional code. Inside the casing 300, the dustproof plate 32 is provided.
0, a lighting substrate 33 on which a light source 331 is mounted
0, an imaging lens 340 and a CCD image sensor 350 are provided.

The dust-proof plate 320 is made of a transparent resin, and prevents dust and dirt from entering the casing 300 from the reading front end 310. The light emitted from the light source 331 of the dust-proof plate 320 onto the two-dimensional code passes through the dust-proof plate 320, and is specularly reflected (specularly reflected) on the two-dimensional code and is incident on the imaging lens 340 at six positions on the optical path. Is provided with a diffusing member 321 for diffusing the light emitted from the light source 331. This diffusion member 321 is, as shown in FIG.
Is formed by performing silk printing on the surface on the light source 331 side.

The light source 331 is composed of a red light emitting diode that emits red light, and six red light emitting diodes are provided at a predetermined position in the casing 300 for the lighting substrate 33.
The drive circuit is driven on the basis of a command from the control circuit 140 (see FIG. 5) to emit red light onto a two-dimensional code label on which a two-dimensional code (not shown) is printed. Has been made. The imaging lens 340 is provided to form an image on the light receiving surface of the CCD image sensor 350 by using light reflected on the two-dimensional code label as incident light. Here, an optical system is configured by the imaging lens 340.

The CCD image sensor 350 is similar to the CCD image sensor 60 of the above-described embodiment, and has a spectral sensitivity peak region near the emission spectrum of the red light emitting diode used as the light source 331.
It has a sensor unit by an array, a charge storage unit and a charge readout unit. For example, a device having an area size of 1/3 inch and an effective pixel number of 330,000 pixels is used. The sensor section serves as a light receiving surface of the CCD image sensor 350. Then, based on a command from the control circuit, the sensor driving circuit is driven, and when the light reflected on the two-dimensional code label and incident on the casing 300 forms an image on the sensor unit on the light receiving surface, the charge readout unit A series of electric signals will be output.

The operation of the pen-type two-dimensional code reader of this modification is substantially the same as the operation of the handy-type two-dimensional code reader of the above-described embodiment, and a description thereof will be omitted.

In the pen-type two-dimensional code reader of the present modification described above, the light source 3 of the transparent dustproof plate 320
Light irradiated on the two-dimensional code from the light source 331 on the surface on the 31 side transmits through the dustproof plate 320, and is specularly reflected (specularly reflected) on the two-dimensional code and is incident on the imaging lens 340 at six positions on the optical path. Since the diffusion member 321 on which the silk printing has been performed is arranged at the portion, the reflected light of the light emitted from the light source 320 onto the two-dimensional code does not directly enter the optical system as specular reflected light. Therefore, the two-dimensional code can be read accurately, and the reading efficiency of this type of reading device is improved. In addition, since the diffusion member 321 is disposed only at six positions on the optical path that is specularly reflected (specularly reflected) on the two-dimensional code and enters the imaging lens 340,
The light emitted from the light source 331 is irradiated onto the two-dimensional code without reducing the amount of light, so that the two-dimensional code can be read accurately without causing a reading trouble.

Further, since the transparent dust-proof plate 320 is originally provided to prevent dust and dirt from entering the casing 300, the silk-screen printing is performed only at six places, and a new member is formed. Without providing the light source 33
The light emitted from 1 can be prevented from directly entering the optical system as specular reflected light, and this kind of scattering means can be provided simply and inexpensively.

In the above-described embodiment, an example in which four light sources 30 are provided and four diffusion members 21 are provided will be described. In a modified example, six light sources 331 and six diffusion members 321 are provided. Although an example has been described, an appropriate number of light sources and diffusion members may be used. In short, any number of light sources may be used as long as the number of light sources is such that the reading operation is performed by the reflected light reflected on the two-dimensional code and the amount of light is assured. However, the diffusing member needs to correspond to the number of light sources.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a two-dimensional code reader of the present invention, FIG. 1 (a) is a front view, FIG. 1 (b) is a bottom view thereof, and FIG. (C) is a side view thereof.

FIG. 2 is a sectional view showing an AA section in FIG.

FIG. 3 is a cross-sectional view showing a BB cross section of FIG. 1 (b).

FIG. 4 is an enlarged view of a main part of FIG. 1 (b).

FIG. 5 is a block diagram showing a block configuration of a two-dimensional code reader including a head unit and a composite unit.

6A and 6B are diagrams showing a schematic configuration of a modified example of the two-dimensional code reader of the present invention. FIG. 6A is a front view, FIG. 6B is a bottom view thereof, and FIG. c) is a side view thereof.

FIG. 7 is a sectional view showing a DD section of FIG. 6 (a).

FIG. 8 is an enlarged view of a main part of FIG. 6 (c).

FIG. 9 is a diagram illustrating an example of a two-dimensional code.

FIG. 10 is a diagram illustrating a configuration example of a two-dimensional code reader.

FIG. 11 is a diagram showing a main part of a head unit of a conventional two-dimensional code reader.

[Explanation of symbols]

Reference numeral 10: casing, 10a: bent portion, 11: reading port, 2
0: dustproof plate, 21: diffusing member, 21a: grained (irregular) portion, 21b: silk printing portion, 30: light source, 40
... mirror, 50 ... imaging lens, 60 ... image sensor,
70: light shielding plate, 300: casing, 310: reading tip side, 311: reading port, 320: dustproof plate, 321 ...
Diffusion member, 331: light source, 340: imaging lens, 350
… Image sensor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-315062 (JP, A) JP-A-6-266875 (JP, A) JP-A-3-12289 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) G06K 7/10

Claims (6)

(57) [Claims] 1. A method for receiving light emitted on a two-dimensional code as two-dimensional optical information, converting the received two-dimensional optical information into a time-series electric signal, and converting the converted time-series electric signal. A two-dimensional code reader for decoding character data corresponding to the two-dimensional code, comprising: a light source that irradiates light onto the two-dimensional code; and light emitted from the light source onto the two-dimensional code. And an optical system that receives the reflected light as optical information, and the light irradiated on the two-dimensional code from the light source in the vicinity of the light source is specularly reflected on an optical path incident on the optical system.
A two-dimensional code reader, wherein a member provided with a means for scattering light emitted from the light source is arranged only at a position where the light source is located. 2. A method according to claim 1, wherein the optical system includes dust, dirt, and the like near the light source.
Place a transparent dust-proof plate to prevent
2. The two-dimensional code reader according to claim 1, further comprising means for scattering light emitted from the light source only at a portion located on the optical path on the light source side surface of the transparent dustproof plate. . 3. The light is scattered only at a portion located on the optical path on the light source side surface of the transparent dustproof plate.
2-dimensional code reading apparatus according to claim 2, characterized in that a make irregularities. 4. Light is scattered only at a portion located on the optical path on the light source side surface of the transparent dustproof plate.
2-dimensional code reading apparatus according to claim 2, characterized in that subjected to silk printing letting. 5. Light is scattered only at a portion located on the optical path on the light source side surface of the transparent dustproof plate.
Further scatter light on the uneven with make irregularities provided
2-dimensional code reading apparatus according to claim 2, characterized in that subjected to silk printing letting. 6. The optical system includes dust, dirt, and the like near the light source.
Place a transparent dust-proof plate to prevent
A light shielding plate is provided vertically on the side of the light source from the transparent dust-proof plate so that light emitted from the light source is not directly incident on the optical system as specular reflection light on the dust-proof plate. The two-dimensional code reader according to claim 1.