JPH11345278A - Bar code reader and bar code reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily read a bar code existing at a long distance by picking up a visible image of a bar code which is formed through an optical system, extracting a contrast pattern of the bar code based on this image data and obtaining bar code information based on the contrast pattern. SOLUTION: An image pickup processing part 5 converts an electric signal inputted from a CCD image sensor 4 into an image signal, performs image processing based on luminance difference and chromaticity difference about the bar code pattern of a bar code image shown based on the image signal and extracts a contrast pattern of the bar code. An internal display 6 shows the bar code image and also shows an area where the contrast pattern of the bar code is extracted. A decoding processing part 8 decodes the contrast pattern of the bar code and outputs bar code information as a decoded result to a memory 9. The memory 9 stores the bar code information outputted from the part 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bar code reader, and more particularly to a bar code reader capable of reading a bar code from a short distance to a long distance. Furthermore,
It relates to a method of reading the barcode.

[0002]

2. Description of the Related Art A conventional bar code reader employs an active system in which a target bar code is irradiated with laser light or LED light and the reflected light is detected to read the bar code. The usable distance of this bar code reader is a range in which the reflected light from the bar code can be detected, and in fact, is a range from a close distance of several cm to a short distance of several meters. For this reason, when articles in a large warehouse or on a high shelf are managed by bar codes, it takes a lot of trouble to read the bar codes of the articles. Therefore, there has been an increasing demand for a bar code reader that can read a bar code at a long distance.

A bar code reader capable of reading a bar code at a long distance is disclosed in, for example, JP-A-6-3330.
There is a bar code reader as disclosed in Japanese Patent Publication No. 74-74. FIG. 4 shows a schematic configuration of the barcode reader, and the configuration will be described below.

[0004] In FIG. 4, a bar code reader includes an LED module 104 in which a plurality of LEDs for irradiating light to a bar code 102 are arranged in a casing 103 having a reading window 103a.
4, an illumination lens 105 for condensing light from the bar code 102, a reflecting mirror 106 for reflecting light reflected from the bar code 102, and a bar code at a short distance reflected by the reflecting mirror 106. 107 having a near-focus imaging lens and a far-focus imaging lens for imaging light from the lens and light from a bar code at a long distance, respectively, and a near-focus imaging lens of the lens barrel 107 A liquid crystal filter 108 for selecting the light passing through the lens and the light passing through the far-focus imaging lens according to the distance of the bar code; a CCD image sensor 109 arranged at the focal position of the lens barrel 107;
An electronic control unit 110 that reads barcode information based on an electric signal from the image sensor 109 is provided.

In this bar code reader, in the case of a bar code located at a short distance, light passing through the near focus imaging lens of the lens barrel 107 is selected by the liquid crystal filter 108 and imaged on the CCD image sensor 109. In the case of a bar code at a long distance, light passing through the far-focus imaging lens of the lens barrel 107 is selected by the liquid crystal filter 108 and formed on the CCD image sensor 109. Then, an electric signal corresponding to the imaged light (barcode information) is sent from the CCD image sensor 109 to the electronic control unit 1.
The bar code information is output to 10 and read.

[0006]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-open No. Hei 6-3330
In the bar code reader described in JP-A-74-74, a lens aperture or the like that causes a decrease in light amount is not required, so that the amount of light reflected from the bar code does not become insufficient up to a certain distance. However, since this barcode reader also employs the active method described above, if the distance from the target barcode is large, loss due to scattering of irradiation light,
The amount of reflected light decreases due to loss due to irregular reflection of the reflected light, and a problem arises in that a sufficient amount of light for reading cannot be obtained.

By increasing the output of the irradiation light (output of the LED module), the readable distance can be increased. However, in the case of the active system, if the distance from the target bar code is too long, the bar code cannot be read. It becomes difficult to set the irradiation position of the reader on the target barcode. For example, at a long distance of several tens of meters, it is difficult to set the irradiation position of the barcode reader on the target barcode.

[0008] An object of the present invention is to solve the above problem and to provide a bar code reader which can easily read a bar code at a long distance. Another object of the present invention is to provide such a barcode reading method.

[0009]

In order to achieve the above object, a bar code reader of the present invention forms a visible image of a bar code to be imaged on a light receiving surface via an optical system,
Imaging means for outputting an electric signal corresponding to the formed visible image, and converting the electric signal output from the imaging means into an image signal, and a bar code image displayed based on the image signal. A captured image processing unit for extracting a contrast pattern in a preset area; displaying a barcode image based on an image signal output from the captured image processing unit; and extracting a barcode contrast pattern. Display means for displaying an area to be displayed, and decoding processing means for decoding bar code contrast pattern data output from the captured image processing means to obtain bar code information.

In the above case, the imaging means includes a CCD image sensor and an optical system having a zoom function for forming a visible image of a barcode to be imaged on a light receiving surface of the CCD image sensor. It may be configured.

[0011] Further, the apparatus may further comprise a memory means for storing barcode information obtained by the decoding processing means, and an output means for outputting the barcode information stored in the memory means to the display means. . In this case, the output unit may be an interface unit connected to an external device. Further, the image pickup means picks up an image of a part or all of the article to which the barcode is attached, the picked-up image processing means outputs picked-up image data of the article picked up by the image pickup means, and the memory means May be configured to store imaged image data of an article output from the imaged image processing unit and barcode information obtained by the decode processing unit in association with each other.

Further, the picked-up image processing means may extract a bar code contrast pattern based on a luminance difference and a chromaticity difference.

According to the bar code reading method of the present invention, a visible image of a bar code formed through an optical system is captured, and a contrast pattern of the bar code is extracted based on captured image data obtained by the capturing. Bar code information is obtained based on the contrast pattern.

In the above case, the extraction of the contrast pattern may be performed based on a luminance difference and a chromaticity difference.

Further, the obtained barcode information may be stored in association with captured image data obtained by capturing an image of a part or all of the article to which the barcode is attached. (Operation) The conventional bar code reader employs an active method of reading the bar code by irradiating the bar code and detecting the reflected light, so that the distance from the bar code cannot be made too large. Also, dozens of meters
At a long distance, it was difficult to set the irradiation position of the barcode reader on the target barcode. On the contrary,
In the present invention, since a visible image of a barcode formed through an optical system is captured and barcode information is read based on the captured image data, the readable distance of the barcode is set. Is determined by the magnification of the optical system.
Generally, an optical lens has a magnification sufficient to read a bar code at a long distance of several tens of meters. As described above, according to the present invention, since a barcode located at a long distance is imaged by zooming up by the optical system, it becomes possible to read a barcode at a long distance which could not be read conventionally.

Further, the bar code reader of the present invention can display picked-up image data, and can pick up a bar code while viewing the displayed picked-up image. Therefore, there is no problem that it is difficult to set the barcode reader on the target barcode at a long distance of several tens of meters as in the related art.

Further, according to the bar code reader having a zoom function of the present invention, the zoom ratio can be arbitrarily adjusted according to the distance of the bar code, so that the bar code can be read from a short distance to a long distance. become.

Further, according to the present invention, the barcode information and the image data of the article are stored in association with each other, so that the image data of the article can be managed together with the barcode.

[0019]

Next, embodiments of the present invention will be described with reference to the drawings.

The bar code reader of the present invention employs a passive system which does not need to irradiate the bar code with light. FIG. 1 is a perspective view of a bar code reader according to an embodiment of the present invention, and FIG. 2 is a block diagram of its main functions. Hereinafter, the barcode reader according to the present embodiment will be described in detail with reference to FIGS.

The bar code reader of this embodiment has a focus
Zoom adjustment switch 1, adjustment motor 2, optical unit 3, C
It comprises a CD image sensor 4, an image processing unit 5, an internal display 6, a reading switch 7, a decode processing unit 8, a memory 9, and an output device (output interface) 10.

The optical section 3 has a zoom function (zoom lens), and the focus and the zoom ratio can be adjusted by the adjustment motor 2. The adjustment of the focus and the zoom ratio of the optical unit 3 by the adjustment motor 2 can be arbitrarily performed by operating the switches of the focus / zoom adjustment switch 1. The optical section 3 is provided in the housing 30 detachably or integrally.

In the housing 30, a CCD image sensor 4, an imaging processing unit 5, an internal display 6, a reading switch 7, a decoding processing unit 8, a memory 9, and an output device (output interface) 10 are housed.

The CCD image sensor 4 forms an image (visible image) of a target bar code on the light receiving surface of the CCD image sensor 4 through the optical unit 3. And outputs an electrical signal corresponding to the information to the imaging processing unit 5.

The imaging processing unit 5 includes a CCD image sensor 4
Is converted into an image signal, and image processing based on a luminance difference and a chromaticity difference is performed on a barcode pattern in a preset area of a barcode image displayed based on the image signal. Then, the contrast pattern of the barcode is extracted. The process of extracting the barcode contrast pattern in the imaging processing unit 5 is started when the reading switch 7 is turned on. The internal display 6 receives the image signal output from the imaging processing unit 5 and outputs the barcode. An image (visible image) is displayed, and an area where a barcode contrast pattern is extracted is displayed on the screen. The housing window 30 is provided with a monitor window 20.
The operator can use the monitor window 20 to access the internal display 6.
You can see the image displayed on the.

The decoding processing section 8 decodes the contrast pattern data of the bar code output from the imaging processing section 5 and outputs the decoding result to the memory 9 as bar code information. The memory 9 stores the barcode information output from the decode processing unit 8.

The output device 10 sends the barcode information stored in the memory 9 to the internal display 6 or an external processing device.

Next, the processing operation of the bar code reader will be described based on an actual use method.

In this bar code reader, when a power supply (not shown) is turned on, a visible image is formed on the light receiving surface of the CCD image sensor 4 via the optical unit 3 and the image is formed from the CCD image sensor 4. An electric signal corresponding to the formed visible image is output to the imaging processing unit 5. In the imaging processing unit 5, CC
The electric signal input from the D image sensor 4 is converted into an image signal, and the image signal is output to the internal display 6. On the internal display 6 to which the image signal has been input,
A captured image of a visible image formed on the CCD image sensor 4 is displayed together with an area where a barcode contrast pattern is extracted. At this point,
The captured image displayed on the CCD image sensor 4 is out of focus.

The operator uses a bar code reader, for example, as shown in FIG.
And pointing the barcode reader in the direction of the target barcode and arbitrarily operating the focus / zoom adjustment switch 1 while looking at the captured image displayed on the internal display 6 to obtain the focus / zoom. Make adjustments. When the operator operates the focus / zoom adjustment switch 1 to perform focus / zoom adjustment, the focus / zoom adjustment of the optical unit 3 is performed by the adjustment motor 2 in accordance with the switch operation. Normally, as shown in FIGS. 1 and 2, the focus and zoom adjustment is performed so that the captured image of the target barcode is displayed on the screen of the internal display 6.

When the picked-up image of the bar code displayed on the internal display 6 is focused and the bar code portion is completely contained in the display area, the operator subsequently operates the bar code displayed in the area. The reading switch 7 for reading is read.

When the reading switch 7 is pressed, the imaging processor 5 extracts a bar code contrast pattern in the display area based on an image signal obtained by converting an electric signal output from the CCD image sensor 4.

When the contrast pattern of the bar code is extracted by the imaging processing unit 5, the contrast pattern data is decoded by the decoding processing unit 8, and
The decoding result is stored in the memory 9 as barcode information. Then, the barcode information stored in the memory 9 is transmitted to the internal display 6 or an external processing device by the output device 10. The internal display 6 that has received the barcode information from the output device 10 displays the barcode information as a character string such as alphanumeric characters.

In the present embodiment, focusing and zooming are manually performed using the focus / zoom adjustment switch 1. However, a well-known out-focus function is provided to automatically perform focusing. Is also good. In this case, the operator only needs to adjust only the zooming, and the operability is improved.

(Other Embodiments) In the above-described embodiment, only the barcode is to be imaged, but the whole or a part of the article to which the barcode is attached is imaged and stored together with the barcode information. Is also possible. In this case, the image data obtained by imaging the article (the image signal obtained by converting the electric signal output from the CCD image sensor 4) is associated with the barcode information in the memory 9 or another memory housed in the housing 30. It is memorized. Then, the output device 10 sends the barcode information and the image data stored in the memory to the internal display 6 or an external processing device.

With the above configuration, it is possible to realize barcode management with image data of an article to which a barcode is attached.

[0037]

According to the present invention constructed as described above, a bar code at a long distance is imaged by zooming up with an optical system. Further, according to the present invention, the barcode can be imaged while viewing the displayed captured image. Therefore, even if the barcode is at a long distance of several tens of meters, the barcode reader can be easily placed on the target barcode. Can be set. Therefore, according to the present invention, it is possible to provide a bar code reader that can easily read a long-distance bar code that could not be read conventionally.

In the present invention, in which the zoom ratio can be arbitrarily adjusted, the zoom ratio can be adjusted according to the distance of the bar code, so that the bar code can be read from a short distance to a long distance. Can be provided.

Further, according to the present invention, in which the barcode information and the picked-up image data of the article are stored in association with each other, the image data of the article can be managed in addition to the management of the article by the barcode. , Providing higher quality management services.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a barcode reader according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of the barcode reader shown in FIG.

FIG. 3 is a diagram showing an actual use mode of the barcode reader shown in FIG. 1;

FIG. 4 is a schematic configuration diagram of a bar code reader disclosed in Japanese Patent Application Laid-Open No. 6-333074.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Focus / zoom adjustment switch 2 Adjustment motor 3 Optical part 4 CCD image sensor 5 Imaging processing part 6 Internal display 7 Reading switch 8 Decoding processing part 9 Memory 10 Output device 20 Monitor window 30 Housing

Claims (9)

[Claims] An imaging unit configured to form a visible image of a barcode to be imaged on a light receiving surface via an optical system, and to output an electric signal according to the formed visible image; A captured image processing unit that converts an electric signal output from the imaging unit into an image signal and extracts a contrast pattern in a preset area of a barcode image displayed based on the image signal; Display means for displaying a barcode image based on the image signal output from the processing means, and displaying an area where a contrast pattern of the barcode is extracted, and a barcode output from the captured image processing means. Decoding means for decoding contrast pattern data to obtain bar code information. 2. The bar code reader according to claim 1, wherein the imaging unit forms a CCD image sensor and a visible image of a bar code to be imaged on a light receiving surface of the CCD image sensor. A bar code reader comprising: an optical system having a zoom function. 3. The bar code reader according to claim 1, wherein a memory means for storing bar code information obtained by said decoding processing means, and the bar code information stored in said memory means is output to said display means. A bar code reader, further comprising: an output unit that performs the output. 4. The bar code reader according to claim 3, wherein said output means is interface means connected to an external device. 5. The barcode reader according to claim 3, wherein the imaging unit captures an image of a part or the entirety of an article to which a barcode is attached, and the captured image processing unit performs the imaging. Means for outputting picked-up image data of the article picked up by the means, wherein the memory means associates the picked-up image data of the article output from the picked-up image processing means with the bar code information obtained by the decoding processing means A bar code reader characterized in that it is stored. 6. The bar code reader according to claim 1, wherein said picked-up image processing means extracts a bar code contrast pattern based on a luminance difference and a chromaticity difference. 7. A bar code visible image formed through an optical system is captured, and a contrast pattern of the bar code is extracted based on captured image data obtained by the capturing. A bar code reading method, further comprising obtaining bar code information. 8. The barcode reading method according to claim 7, wherein the extraction of the contrast pattern is performed based on a luminance difference and a chromaticity difference. 9. The bar code reading method according to claim 7, wherein the obtained bar code information is associated with captured image data obtained by imaging a part or all of an article to which the bar code is attached. A bar code reading method, wherein the bar code is read and stored.