JP2002304594A - Information code existence estimating method, information code reading apparatus and information code existence estimating program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically estimate that an information code exists in an area to be read with high probability by making it unnecessary to provide any illuminating light for reading. SOLUTION: A stationary information code reading apparatus 1 is provided with a number of bright/dark point memory 14b for storing the change of bright points and dark points when scanning for each area to be checked for one picture area and a memory 17 for storing bright/dark points for storing the data for one picture area. The data stored in the number of bright/dark point memory 14b for one picture area are transferred to the memory 17 for storing the bright/dark pints. Then, data for one picture area are stored in the number of bright/dark point memory 14b again, and the contents of the number of bright/dark point memory 14b are compared with the contents of the memory 17 for storing the bright/dark points for each area to be examined by a control circuit 8. When the number of areas to be examined where the number of bright and dark points whose change is generated between adjacent pixels exceeds the prescribed number of points to be judged becomes more than the number of areas to be judged, it is estimated that an information code exists in the area to be read with high probability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information code existence estimating method, an information code reading device, and an information code existence estimating program for estimating the existence of an information code composed of a light and dark pattern.

[0002]

In recent years, bar codes, Q
Many information code reading devices are installed in stores for decoding information codes represented by R codes and recognizing contents. This type of information code reading apparatus is designed to decode an information code by recognizing the information code printed on a sheet of paper or the like to a reading target area by a user, and recognize the content.

A conventional information code reader requires an illumination light emitting diode (hereinafter, referred to as an LED) to read an information code in an area to be read. That is, the LED is turned on in the reading target area, for example, about 700 to
By setting the illuminance to about 800 lux, it is possible to decode (decode) a bright point and a dark point of the information code pattern by the reflected light.

In this case, when starting the reading operation,
In order for the information code reader to recognize that the object on which the information code is printed is present in the reading target area, it is necessary to provide a separate reading switch or an object detection sensor (proximity sensor, photo interrupter, etc.). is there.

In particular, in a stationary information code reading device, when an information code printed on a sheet of paper or the like is inserted into an area to be read, the information code is automatically detected and a reading operation is performed. It is desirable to provide the object detection sensor without providing the reading operation start switch operated by the user at the time of reading, because the convenience is improved for the user.

However, providing a switch for starting a reading operation or a sensor for detecting an object complicates the operation of the switch and increases the cost of providing a detection circuit. A method of sequentially reading the information code at the timing when the information code is turned on is also conceivable. However, for example, when a stationary information code reading device is installed in a store, the lighting or blinking of the LED may be annoying to the user or the customer, or the LED may be constantly lit or lit at a constant period. In addition, the LED deteriorates quickly, the light amount decreases, and the replacement cycle becomes short, which is not preferable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to automatically estimate that the existence probability of an information code is high without bothering the user, and thereby to read the information code. It is an object of the present invention to provide an information code existence estimating method, an information code reading device, and an information code existence estimating program which can lengthen an LED replacement cycle without having to provide an operation switch and an object detection sensor. .

[0008]

According to the information code existence estimating method of the present invention, each pixel data of the image obtained in the reading target area is set in a state where the reading illumination is not turned on in the imaging process. , A bright point and a dark point are determined and stored (light / dark determination step, determination result storage step). Further, while scanning the pixels of the image in a predetermined direction,
A pixel that changes from a bright point to a dark point or a pixel that changes from a dark point to a bright point between adjacent pixels is determined. At this time, since the information code composed of the light-dark pattern has a pattern in which the boundary between the light point and the dark point is clear, the change in light-dark (the number of light-dark points) between adjacent pixels has a high probability even without reading illumination. On the other hand, when the boundary between the bright point and the dark point is not clear, such as a picture, the detection probability of the number of bright and dark points is low because the change in brightness between adjacent pixels is small.

Next, by comparing the number of light and dark points of the previous image with the determination result of the change in light and dark of the current image (light and dark point change counting process), the change with respect to the previous image is counted, and this change occurs. When the number of pixels exceeds a predetermined number of determination points, it is estimated that the probability that an information code composed of a light and dark pattern exists in the read target area is high (estimation process). That is, when the information code enters the reading target area, the information code has a large change in brightness between adjacent pixels, so that the number of pixels satisfying the condition exceeds a predetermined judgment point. Conversely, even if a picture or the like enters the reading target area, since the brightness change between adjacent pixels is small,
The number of pixels satisfying the condition rarely exceeds the number of judgment points. Therefore, it is possible to detect that the probability that the information code exists in the reading target area is high without turning on the reading illumination in the reading target area.

According to the information code existence estimating method of the present invention, an image obtained by imaging the area to be read in the imaging step is divided into a plurality of inspection areas (division step). Further, a bright point and a dark point are determined for each pixel data of the image of the image to be read, pixels of the image are scanned in a predetermined direction, and pixels which change from a bright point to a dark point between adjacent pixels, or dark pixels. A pixel that changes from a point to a bright point is determined and stored as the number of bright and dark points for each of a plurality of inspection areas (light / dark determination process, determination result storage process). At this time, since the information code composed of the light and dark patterns has a pattern in which the boundary between the light point and the dark point is clear, the change in light and dark between adjacent pixels (the number of light and dark points)
Is detected with a high probability even without illumination for reading. Conversely, when the boundary between a bright point and a dark point is not clear, such as a picture, the change in brightness between adjacent pixels is small and the number of bright and dark points is small. Has a low detection probability. The number of bright and dark points is counted for each of a plurality of inspection areas.

Next, the number of light and dark points of the previous image is compared with the judgment result of the current image, the number of pixels having a change in the number of light and dark points is counted. Is counted, and it is estimated that the probability that an information code exists is high when the number of inspection areas exceeds a predetermined number of determination areas (bright and dark point change counting step, estimation step).

That is, when the information code enters the area to be read, since the information code has a large change in brightness between adjacent pixels, the number of inspection areas satisfying the condition of exceeding the number of judgment points is determined by the predetermined number of judgment areas. Exceeds. Conversely, even if a picture or the like enters the reading target area, the number of inspection areas satisfying the condition of exceeding the number of judgment points exceeds the predetermined number of judgment areas due to a small change in brightness between adjacent pixels. Less is. Therefore, it is possible to detect that the probability that the information code exists in the reading target area is high without turning on the reading illumination in the reading target area.

Further, according to the invention of claim 3, according to claim 2,
Since the number of determination zones can be set to different values in the invention of the above, the sensitivity for estimating that the probability that the information code exists in the read target area is high can be adjusted. That is, since the number of determination zones can be set to different values by the user or the like, when the reading illumination is turned on in the reading target area to decode the information code, the reading illumination is turned on or the information code is turned on. The degree of decryption can be adjusted.

According to the fourth aspect of the invention, the operation is as follows. That is, the imaging unit captures an image of the reading target region, and the light / dark determination unit determines a bright point and a dark point for each pixel data of the captured image in the reading target region. Further, the light / dark determining means determines a pixel which changes from a bright point to a dark point or a pixel which changes from a dark point to a bright point between adjacent pixels. At this time, since the information code composed of the light-dark pattern has a pattern in which the boundary between the light point and the dark point is clear, the change in light-dark (the number of light-dark points) between adjacent pixels has a high probability even without reading illumination. Conversely, when the boundary between the bright point and the dark point is not clear, such as a picture, the change in the brightness between adjacent pixels is small and the probability of detecting the number of bright and dark points is low. The judgment result storage means stores this value. The control means counts the change with respect to the previous image by comparing the number of light and dark points of the previous image with the determination result of the change in light and dark of the current image, and the number of pixels in which the change occurs becomes a predetermined determination point. When it exceeds, it can be estimated that there is a high probability that an information code composed of a light and dark pattern exists in the reading target area.

According to the fifth aspect of the invention, the operation is as follows. That is, the imaging unit captures an image of the reading target region, and the light / dark determination unit determines a bright point and a dark point for each pixel data of the captured image in the reading target region. Also,
The brightness determining means determines a pixel that changes from a bright point to a dark point or a pixel that changes from a dark point to a bright point between adjacent pixels. At this time, since the information code composed of the light-dark pattern has a pattern in which the boundary between the light point and the dark point is clear, the change in light-dark (the number of light-dark points) between adjacent pixels has a high probability even without reading illumination. Conversely, when the boundary between the bright point and the dark point is not clear, such as a picture, the change in the brightness between adjacent pixels is small and the probability of detecting the number of bright and dark points is low. The determination result storage means stores this value for each of the plurality of inspection areas. The control unit compares the number of bright and dark points of the previous image with the determination result of the current image, and counts the number of pixels having a change in the number of bright and dark points. The control means counts the number of the inspection areas when the number of the pixels exceeds a predetermined judgment point, and when the number of the inspection areas exceeds the predetermined judgment area, the probability that the information code exists is small. It can be estimated to be high.

According to the sixth aspect of the present invention, since the number of determination zones to be estimated in the fifth aspect of the invention can be set to different values, the probability that the information code exists in the read target area is high. The sensitivity for estimating the effect can be adjusted. That is, since the number of determination zones can be set to different values by the user or the like, when the reading illumination is turned on in the reading target area to decode the information code, the reading illumination is turned on or the information code is turned on. The degree of decryption can be adjusted.

According to the information code existence estimating method of the ninth aspect, the imaging process is performed in the same manner as in the method of the first aspect. Then, a bright point and a dark point are determined (determination process), and the determination result is stored as a pixel bright / dark point (storage process). Next, by comparing the pixel light-dark point of the previous image with the determination result of the current image for each pixel, the number of pixels having a change in the determination result of the current image with respect to the previous image is counted (counting). process). At this time, similarly to the method invention according to the first aspect, detection is performed with a high probability even without illumination for reading. In other words, when the information code enters the reading target area, the information code has a clear bright point and a dark point, so that the number of pixels satisfying the condition exceeds a predetermined judgment point. Therefore, it is possible to estimate (detect an estimation process) that the probability that the information code exists in the reading target area is high without turning on the reading illumination in the reading target area.

According to the information code existence estimating method of the tenth aspect, the imaging step is performed and the dividing step is performed similarly to the method invention of the second aspect. Then, the determination step according to the ninth aspect is performed, and the determination result is stored as the pixel light / dark point. Then, the pixel light and dark points of the previous image and the determination result of the current image are compared for each pixel, and the number of pixels having a change in the pixel light and dark points is counted for each of the plurality of inspection areas (a counting process). Since the information code is composed of a bright point and a dark point, it is detected with a high probability even without illumination for reading. That is, when the information code enters the reading target area,
The number of inspection areas satisfying the condition of exceeding the number of judgment points exceeds a predetermined number of judgment areas. Therefore, it is possible to estimate and detect that the probability that the information code exists in the reading target region is high without turning on the reading illumination in the reading target region.

According to the information code existence estimating method of the present invention, the number of bright points or dark points is determined in a state where the bright points or dark points of the pixel data of the image captured in the image capturing process are determined. The number is counted, and the result of counting the image is stored as the number of light and dark (a counting process, a storing process). Next, the contrast number of the previous image and the counting result of the current image are compared, and when the change in the contrast number exceeds a predetermined number, it is determined that there is a high probability that the information code including the contrast pattern exists in the reading target area. It is estimated (estimation process).

At this time, since the information code is composed of a bright point and a dark point, the information code is detected with a high probability without illumination for reading. That is, when the information code enters the reading target area, the condition that the number of light and dark exceeds a predetermined number by comparison between the previous image and the current image is satisfied. Therefore, it is possible to estimate that the probability that the information code exists in the reading target area is high without turning on the reading illumination in the reading target area.

According to the twelfth aspect of the present invention, the image pickup means picks up an image of the area to be read, and the judgment means judges a bright point and a dark point for each pixel data of the imaged image in the area to be read. In this case, since the information code is composed of a light point and a dark point, when the state transits to a state in which the information code exists in the reading target area, or when the state changes from a state in which the information code exists in the reading target area. , Even if there is no illumination for reading, it is detected with a high probability, and the storage means stores this value as a pixel light / dark point. The control unit counts the number of pixels that have changed with respect to the previous image by comparing the pixel light / dark point of the previous image with the determination result of the current image for each pixel, and determines that the number of counted pixels is a predetermined number. It is estimated that there is a high probability that an information code composed of a light and dark pattern exists in the reading target area when the number of judgment points exceeds the number of judgment points.

According to the thirteenth aspect, the first aspect is provided.
In the same manner as in the second aspect of the invention, since a bright point and a dark point are determined for each pixel data of an image, an information code is detected with a high probability even without illumination for reading. The storage unit stores the determination result as a pixel light-dark point, and the control unit compares the pixel light-dark point of the previous image with the determination result of the current image for each pixel, and a change occurs in the pixel light-dark point determination result. The number of pixels is counted for each of the plurality of inspection areas. The control means counts the number of inspection areas when the number of pixels exceeds a predetermined determination point, and stores information in the read target area when the counted number of inspection areas exceeds the predetermined determination area number. It is estimated that the probability that the code exists is high.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment in which the present invention is applied to a stationary information code reader 1 such as a store will be described with reference to FIGS. explain. FIG. 2 shows a state on which it is assumed that the stationary information code reader 1 of the present embodiment is actually used. The stationary information code reader 1 is fixed to an arm 3 erected on a stand 2 and is installed so as to set a reading target area downward. The stationary information code reader 1 is connected to an external computer (not shown) via a cable 5 from a communication interface circuit 4 described later.

FIG. 1 shows the electrical configuration of the stationary information code reader 1. Stationary information code reader 1
A light-emitting diode (hereinafter, referred to as an LED) 6 as an illumination for reading that irradiates light to a reading target area;
CC that captures an image by receiving light reflected from the reading target area
The D area sensor 7 and a control circuit 8 serving as control means for performing operations such as controlling the drive timing of the D area sensor 7, and light and dark for performing operations such as determining a bright point and a dark point in accordance with a control signal of the control circuit 8 It is mainly configured with a binarization circuit 9 as a judging means.

The control circuit 8 has a CPU (Central Process
ng Unit), ROM, RAM, etc.
Each component of the stationary information code reader 1 is operated in accordance with a program stored in M.
Further, a work memory for each configuration operation program is allocated to the RAM.

The LED 6 is configured to irradiate red light in accordance with an instruction from the control circuit 8 to irradiate an area to be read so as to have an illuminance of about 700 to 800 lux. Also, the CCD area sensor 7 as an image pickup means
It is composed of a plurality of light receiving elements such as photodiodes (not shown) arranged two-dimensionally, and captures an image of a reading target area according to a control signal of the control circuit 8. At the time of imaging, the light receiving element converts the electric signal into an electric signal, and sequentially outputs an analog signal of pixel data of an image to the amplifier circuit 11 based on a signal reading timing of a synchronizing pulse generated by the synchronizing pulse generating circuit 10. I have.

The amplifier circuit 11 converts the analog signal of the pixel data output from the CCD area sensor 7 into a control circuit 8
The amplifier is configured to amplify and output a voltage with an amplification factor corresponding to the gain control voltage input from the controller.

The voltage output terminal of the amplifier circuit 11 is connected to the analog input terminal of the A / D conversion circuit 12. A /
The D conversion circuit 12 converts the analog signal voltage into a digital signal and converts the analog signal voltage into a digital signal.
Is configured to be output.

On the other hand, the synchronization pulse generating circuit 10
A synchronization pulse sufficiently smaller than the pulse of the pixel data output from the area sensor 7 is output in accordance with an instruction from the control circuit 8, and the first address generation circuit 13 outputs the synchronization pulse. While counting, respective addresses are generated for each area of the image memory 14 as needed.

The image memory 14 is an image data memory 1
4a and a light / dark point number memory 14 as a judgment result storage means
b, and a two-dimensional image memory 14c. The image memory 14 is a signal comprising a data bus for transmitting and receiving data and a control signal line for controlling read / write (read / write) of the image memory 14. The line is connected to the control circuit 8. A digital output of the A / D conversion circuit 12 is connected to an input terminal of the binarization circuit 9.

The binarizing circuit 9 interposes a dead zone of a predetermined luminance range predetermined by the control circuit 8 (see FIG. 3), and sets a luminance range of a bright point, a luminance range of a dark point or a luminance range of a dead zone. In addition to dividing the specified luminance level, the input pixel data is distributed as a bright point, a dark point, or a point in a dead zone based on the specified luminance level, and can be output to the two-dimensional image memory 14c in the image memory 14. It is configured. The address of the two-dimensional image memory 14c stored at this time is provided from the first address generating circuit 13, and is stored in the two-dimensional image memory 14c as data for each pixel output from the CCD area sensor 7. ing.

Further, the binarizing circuit 9 performs the following based on an address control signal transmitted from the first address generating circuit 13.
While one image area is divided into inspection areas composed of a plurality of areas, a block address for the light / dark point number memory 14b is specified for each inspection area. Then, the binarization circuit 9 obtains the maximum value and the minimum value of the luminance for each inspection area with respect to the obtained pixel data, and sets the luminance regulation level in each of the divided inspection areas. At the same time, when scanning within one image area, the change of the bright point and the dark point with respect to the luminance specified level of the pixel data is sequentially detected, counted for each inspection area, and stored in the bright / dark point number memory 14b. The number of light and dark points for each inspection area is stored.

The switch group 15 is composed of, for example, function keys 15a, and is configured so that sensitivity adjustment and various information described later can be input. (See FIG. 2) The liquid crystal display 16 displays a two-dimensional code read in accordance with a control signal from the control circuit 8.

The memory 17 for storing the number of light and dark points has at least a storage area equal to or larger than the memory 14b for light and dark points, and is configured so that data stored in the memory 14b for light and dark points can be transferred internally in accordance with a control signal of the control circuit 8. ing. The second address generation circuit 18 is connected to the control circuit 8, and receives a signal from the control circuit 8 to receive the number of bright and dark points stored in the memory 17.
And the address of the image memory 14 can be designated correspondingly.

The stationary information code reader 1 has a built-in battery (not shown) and a power supply circuit using the battery, and is configured to supply power to each component of the stationary information code reader 1. ing.

Next, the operation of the above configuration will be described. Hereinafter, the process of storing data for one image area in the image memory 14 when capturing an image of the reading target area will be described with reference to the flowchart of FIG. Note that the first address generation circuit 13 includes an image data memory 14a and a two-dimensional image memory 14c designated by a control signal of the control circuit 8.
Are set in advance, and the binarization circuit 9
It is assumed that one image area obtained by imaging the area to be read is divided into inspection areas in accordance with an instruction of a control signal from the control circuit 8, and an initial block address of the memory 14b is set. For the sake of simplicity, the binarization circuit 9 previously obtains the maximum value and the minimum value of the luminance for each inspection area, and calculates the specified luminance levels in all the divided inspection areas. And

In the stationary information code reader 1,
The light reflected on the area to be read enters the CCD area sensor 7 of the stationary information code reader 1 (Step S).
1).

The CCD area sensor 7 of the stationary information code reader 1 converts incident light into an analog signal at predetermined intervals and outputs the signal to the amplifier circuit 11 in accordance with the synchronization pulse of the synchronization pulse generation circuit. The amplifier circuit 11 amplifies the analog signal with an amplification factor corresponding to the gain control voltage set by the control circuit 8, and outputs the analog signal to the A / D conversion circuit 12. The A / D conversion circuit 12 includes a control circuit 8
Is converted into a digital signal in accordance with the timing signal from, and is output as pixel data to the binarization circuit 9 and the image data memory 14a in the image memory 14 (step S2). The binarization circuit 9
The input pixel data is sorted into a bright point, a dark point, or a dead zone based on a predetermined luminance specified level, and the two-dimensional image memory 14c in the image memory 14 is allocated.
(Step S3).

The control circuit 8 writes data to the image data memory 14a and the two-dimensional image memory 14c.
A control signal is generated, and the data obtained in step S3 is stored at an address corresponding to the image data memory 14a and the two-dimensional image memory 14c (step S3).
4). The binarizing circuit 9 specifies a block address of the bright / dark point number memory 14b corresponding to the transmitted pixel data based on the address control signal transmitted from the first address generating circuit 13 (Step S5). The binarization circuit 9
The light point and dark point of the obtained pixel data are compared with the light point and dark point of the pixel data obtained last time (step S6). That is, the change of the light point and the dark point is detected based on the change of the electric signal output from each light receiving element of the CCD area sensor 7 in synchronization with the synchronization pulse of the synchronization pulse generation circuit 10. At this time, the binarization circuit 9 counts the change for each inspection area, and stores
The number of bright and dark points for each inspection area is stored in the designated block address b (step S7). Thereafter, the control circuit 8 stores the data for one image area in the two-dimensional image memory 1 based on the number of pulses output to the synchronous pulse generation circuit 10.
4c, image data memory 14a and light / dark point number memory 14
b (step S8), and if it is determined that data for one image area is not stored (step S8: No), the control circuit 8 causes the synchronization pulse generation circuit 10 to output the synchronization pulse. (Step S
9) An electric signal is generated from the next light receiving element of the CCD area sensor 7 and the address generated by the first address generation circuit 13 is incremented (step S1).
0). The first address generation circuit 13 specifies this address to the binarization circuit 9 and the image memory 14. Then, the process is repeated from step S2 again, and the pixel data for one image area is sequentially updated in the two-dimensional image memory 14c, the image data memory 14a, and the bright-dark point number memory 14b.

When the control circuit 8 determines that the pixel data for one image area has been stored in the two-dimensional image memory 14c, the image data memory 14a, and the number of bright and dark points memory 14b (step S8: Yes), the control circuit 8 determines whether or not the pixel data is to be read later. Shift to the processing of the information code existence estimating method (step S1).
1).

In this way, the pixel data for one image area is rewritten to the image data memory 14a,
The binary data of the pixel data is stored in the two-dimensional image memory 14.
c, and the number of bright and dark points for each inspection area for one image area is rewritten to the bright and dark point number memory 14b.

In FIG. 2, a stationary information code reader 1 is shown.
The document B on which a picture or the like is printed is randomly opened in the reading target area (see FIG. 2 in a chevron shape.
The hatched area is assumed to be entirely black.) FIG. 5 shows a pattern imaged from the reading target area at this time (note that the hatched portion in FIG. 5 is entirely painted in black). Actually, an area of 640 pixels × 480 pixels is divided into inspection areas. Here, for the sake of simplicity, FIG. 5 shows a simplified inspection area configuration divided by the binarization circuit 9. Is shown. That is, one image area is divided into, for example, 7 × 7 rectangular inspection areas, and one inspection area has, for example, 10 × 10 pixels. FIG. 6 schematically shows an example of the contents of (a) the number of bright and dark points memory 14b and the corresponding (b) structure of the address and data in one image area divided into inspection areas. .

Next, the details of the method of estimating the presence of the information code in the read target area in the program loaded in the ROM of the control circuit 8 will be described with reference to the flowchart of FIG. In the initial state, as described above, the stationary information code reading device 1 transmits the pixel data for one image area through the CCD area sensor 7, the amplification circuit 11, the A / D conversion circuit 12, and the binarization circuit 9. To the image data memory 14
a, rewriting to the two-dimensional image memory 14c,
Divides the imaged pixel data of one image area into a plurality of inspection areas, and stores the change in lightness and darkness in the inspection area in the light-dark point number memory 14b (step T1). After that, the first address generation circuit 13 transmits a signal to the control circuit 8 indicating that data for one image area has been stored in the image memory 14. The control circuit 8 receives a signal indicating that data for one image area has been stored in the image memory 14, and transmits an address generation start signal to the second address generation circuit 18. The second address generation circuit 18 designates the addresses of the bright / dark point number memory 14b and the bright / dark point number storing memory 17. The control circuit 8 includes a memory 17 for storing the number of light and dark points.
Is recognized as the initial state, the data for one image area of the bright / dark point number memory 14b is stored in the bright / dark point number storing memory 17 via the second address generating circuit 18 (step T2). At this time, since only pixel data for one image area has been captured from the initial state,
All data in the bright / dark point number memory 14b in the initial state are “0”.
"0" is stored in the memory 17 for storing the number of bright and dark points.
Is forwarded to all addresses.

FIG. 8 shows a state in which a piece of paper on which the information code P has been printed is inserted, and FIG. 9 shows a symbol imaged in the reading target area at this time.
(The hatched portions in FIGS. 8 and 9 are assumed to be entirely painted in black.) Under the condition where the reading target area is illuminated by dim light (illuminance of about 100 lux), As shown in FIG. 9, a document on which an information code P is printed is inserted into a reading target area, and the stationary information code reading apparatus 1 rereads the data for one image area into the CCD area sensor 7, the amplification circuit 11, the A / A The image data is read via the D conversion circuit 12 and the binarization circuit 9, and the image data memory 14a, the two-dimensional image memory 14c, and the bright / dark point number memory 14b are rewritten (step T3). FIG. 10 schematically shows (a) an example of the contents of the bright / dark point number memory 14b in one image area at this time and (b) an example of the corresponding address and data structure.

That is, the data (FIG. 6) corresponding to the original pattern (FIG. 5) imaged in the reading target area is stored in the memory 17 for storing the number of light and dark points, and a document on which the information code is printed is inserted. The data (FIG. 10) corresponding to the symbol (FIG. 9) after the execution is stored in the light / dark point number memory 14b.
Note that the number of bright and dark points is counted when the read target area changes from white (bright point) to black (dark point) or from black to white when scanning the pixel by pixel, so the original symbol (FIG. 5) , Only the portion of the boundary between white and black is counted by the binarization circuit 9 and the number of bright and dark point memories 14b is stored for each inspection area.
And stored in the memory 17 for storing the number of light and dark points. Incidentally, actually, the counting is performed in correspondence with the number of scanning lines for scanning the inspection area, but numerical values are appropriately shown for simplification of description. (Additionally, at this time, the data of the bright point and the dark point stored in the two-dimensional image memory 14c at this time are based on the pixel data of the area to be read at an illuminance of about 100 lux. Since the points are determined, the brightness and the contrast are low, and it is difficult to correctly decode the information code even if the control circuit 8 performs a normal decoding process.) The first address generation circuit 13 is also the same. Then, a signal to the effect that data for one image area has been stored in the image memory 14 is transmitted to the control circuit 8. The control circuit 8 receives a signal indicating that data for one image area has been stored in the image memory 14 and transmits an address generation start signal to the second address generation circuit 18. The second address generation circuit 18 designates each address corresponding to the divided inspection area in the memory 14b for the number of bright and dark points and the memory 17 for storing the number of bright and dark points of the image memory 14 (step T4).

The control circuit 8 subtracts the content of the memory 17 for storing the number of bright and dark points from the content of the bright and dark point memory 14b for each inspection area (step T5), and stores the result in the work memory. The control circuit 8 determines whether the comparison of the data of the inspection area for one image area has been completed (step T).
6) If not completed (step T6: No), the control circuit 8 increments the address (step T7) and specifies the address to the second address generation circuit 18. Then, in step T4, the second address generation circuit 18 designates the respective addresses in the bright / dark point number memory 14b and the bright / dark point number storage memory 17, and repeats steps T4 to T7. Repeat until it is determined that the comparison of the data in the inspection area is completed. These subtraction data are stored as shown in FIGS. 11 (a) and 11 (b). As a result, the number of bright and dark points is compared for each inspection area in two consecutive image areas.

After the comparison of the data of the inspection area for one image area is completed in step T6 (step T6: Ye
s) The control circuit 8 calculates what percentage of the total number of inspection areas exceeds a predetermined judgment point as a result of subtracting the number of light and dark points for each inspection area (step T8). For example, in FIG. 11, the control circuit 8 calculates what percentage of data indicating a value of, for example, 4 or more exists in the work memory with respect to the total number of inspection areas (49), and calculates 7/4.
9 = about 14.3%.

After that, the control circuit 8 calculates the ratio of the inspection area where the result of subtraction of the number of light and dark points exceeds the number of judgment points, and judges whether or not the value exceeds the number of judgment areas (step T9). For example, in FIG. 11, the control circuit 8
For example, if the number of determination areas is 10%, 10% <1
Since it is 4.3%, it is determined that it exceeds. In addition,
At this time, the numerical value of 10% is specified by the user via the switch group 15. When the ratio of the inspection areas satisfying the above-mentioned condition exceeds the number of the determination areas (step T9: Yes), the control circuit 8 estimates that the existence probability of the information code P is high in the image area. Then, the control circuit 8 decodes the information code by a decoding process described later (step T10). If the number does not exceed the number of determination zones in step T9, it is estimated that the information code does not exist, and the process returns to step T2, where the bright-dark point number memory 1
The content of 4b is stored in the memory 17 for storing the number of light and dark points, an image of one image area is taken again, and steps T2 to T9 are similarly repeated until the decoding process is performed in step T10.

The decoding process will be described below with reference to the flowchart shown in FIG. The control circuit 8 causes the LED 6 to illuminate the reading target area during the decoding process (step U1). The illuminance of the reading target area changes from about 100 lux to about 700 to 800 lux, and at that timing, the control circuit 8
As described above, the pixel data of the read target area is stored in the image data memory 14a (step U2). The binarizing circuit 9 sorts the pixel data in which the brightness and contrast of the reading target area are emphasized into bright points or dark points, and outputs the bright points or dark points to the two-dimensional image memory 14c.
Stores the contents in the address specified by the first address generation circuit 13 (step U3).

The control circuit 8 performs normal (conventional) decoding with reference to the contents of the binarized two-dimensional image memory 14c (step U4). In this manner, the control circuit 8 can perform the decoding process based on the pixel data in which the brightness and the contrast are enhanced. It is also possible to recognize the decrypted data and output the recognition signal to the outside via the communication interface circuit 4 as needed.

When a large area, such as a symbol, having a large area and unclear light and dark is inserted into the reading target area, the two consecutive image areas stored in the memory 17 for storing the number of bright and dark points and the memory 14b for bright and dark points are used. The difference in the number of light and dark points for each inspection area is reduced. Therefore, if the number of areas for determining the number of light and dark points is adjusted in advance, even if a symbol such as a symbol whose brightness is indistinct is inserted into the read target area at the time of estimating the presence of the information code in the read target area, the decoding is not performed. The probability of transition to processing is reduced.

At this time, if the number of determination zones is reduced, the ratio of shifting to the decoding process by estimating that the information code is present in the reading target area increases and the sensitivity increases. Therefore, it is necessary to finely adjust the number of determination areas based on the relationship with the illuminance of ambient light. Therefore, the number of determination zones is adjusted by the switch group 15 provided with function keys and the like. As a result, the sensitivity can be adjusted, and the adjustment can be made so that it is unnecessary to turn on the decoding illumination unnecessarily and shift to the decoding process.

According to such an embodiment, the light / dark point number memory 14b of the image memory 14 stores the change in lightness / darkness of the adjacent pixels of the image for one image area, and stores it in the light / dark point number storage memory 17. Is the number of bright and dark points memory 1 for one image area
The previous content stored in 4b is stored. Control circuit 8
Detects the temporal change in the number of light and dark points in order to compare the number of light and dark points in the inspection area of two consecutive image areas,
When the number exceeds the predetermined number of determination zones, the presence of the information code P is estimated, and then the LED 6 is turned on to perform a normal decoding process.

That is, the stationary information code reader 1
When installed in a place with low ambient illuminance (about 100 lux), it is possible to detect the movement of the number of bright and dark points between inspection areas even if only an image with low brightness and low contrast can be obtained. When the movement of the number of light and dark points between the inspection areas is detected, the built-in LED 6 irradiates red light to the reading target area and performs actual decoding processing to obtain pixel data with clear brightness and contrast. And normal (conventional) decryption processing can be performed. As a result, there is no need to separately provide a reading operation switch or an object detection sensor, and even if the reading target area is dim, the LED does not need to be turned on and the information code is automatically output without bothering the user. Can be decoded by lighting the LED 6 after estimating the existence of.

Since there is no need to constantly light or blink the LED 6, power consumption can be reduced, and
The replacement cycle can be lengthened by lengthening the deterioration cycle of D6.

By operating the switch group 15, the number of determination zones can be adjusted, so that the sensitivity can be changed and it is not necessary to shift to the decoding process unnecessarily. Since the lighting of the LED 6 is reduced, the power consumption can be further reduced, and the replacement cycle of the LED 6 can be lengthened.

(Second Embodiment) The second embodiment is different from the first embodiment in that the method of counting the number of bright and dark points stored in the bright and dark point memory 14b and the information in the read target area This is a method for estimating the existence of a code. This method will be described below with reference to the flowcharts shown in FIGS. The different parts are indicated by adding a suffix a to the step numbers. FIG.
11 is a flowchart illustrating a process of storing data for one image area in the image memory 14 when capturing an image of a reading target area according to the embodiment. The difference from the first embodiment is step S7a. In step S6, the binarization circuit 9 compares the light point and dark point of the obtained pixel data with the light point and dark point of the pixel data obtained last time, and determines the change in all the inspection areas. It counts and stores it in the bright-dark point memory (step S7a). That is, the change in the brightness of one entire image area is counted.

FIG. 14 is a flowchart showing a method for estimating the presence of an information code in a read target area according to the second embodiment. The difference from the first embodiment is that steps T4a, T5a and T9
a, and steps T6, T7 and T8 are deleted.

That is, when the image data memory 14a, the two-dimensional image memory 14c, and the number of bright / dark points memory 14b are rewritten (step T3), the second address generating circuit causes the bright / dark area in which the count value of the change in the entire inspection area is stored. The addresses of the point memory and the memory for storing the number of light and dark points are designated (step T4a). The control circuit 8 subtracts the data of the memory for storing the number of light and dark points from the data of the specified memory of the number of light and dark points and makes a comparison (step T5a). Control circuit 8
If the result is higher than the determination score, the process proceeds to the decoding process (step T10). If the result is not higher than the determination score, the process returns to step T2 and returns to step T2 to step T5.
a will be repeated.

As a result, the routine for subtraction and comparison for each inspection area in the first embodiment is deleted, and
The same operation and effect as those of the embodiment can be obtained, and the processing can be simplified to quickly obtain the result.

It is needless to say that there is no need to divide the inspection area into inspection areas. In this case, however, the processing for dividing the inspection area in the binarizing circuit 9 can be omitted, and it is not necessary to specify a block address in step S5. Processing can be simplified and results can be obtained more quickly.

(Third Embodiment) FIG. 15 shows a third embodiment of the present invention. What is different from the first and second embodiments is that the information code P is decoded. Is the portion to be read. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. In addition, the stationary information code reader 20 is
Although the external configuration is different from the stationary information code reader 1, the electrical configuration of the stationary information code reader 20 is the same as that of the stationary information code reader 1.

An image display device 21 installed in an area to be read by the stationary information code reading device 20 is connected to a cable 22 capable of transmitting an image signal, and the other end of the cable 22 transmits an information code image. It is connected to a possible computer or imaging device (not shown). The stationary information code reading device 20 is installed so that the display surface 21 a of the information code of the image display device 21 is included in the reading target area of the stationary information code reading device 20.

At this time, when an image signal is transmitted by a computer (not shown) via the cable 22, the image display device 21 displays the information code P. Image display device 2
1 is a transition from a state where the information code P is not displayed to a state where the information code P is displayed. At this time, the information code P is stored in the stationary information code reader 20.
, The information code P can be decoded after estimating that the existence probability of the information code P is high by the operation described in the first embodiment. As a result, effects equivalent to those of the first and second embodiments can be obtained.

(Fourth Embodiment) FIG. 16 shows a fourth embodiment of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals. Description is omitted. The stationary information code reader 30
Although the external configuration is different from that of the stationary information code reader 1, the electrical configuration of the stationary information code reader 30 is the same as that of the stationary information code reader 1. The stationary information code reader 30 is installed on a stand 31 via an arm 32 in a store or the like. The stationary information code reader 30 is connected to an external computer (not shown) via a cable 33 capable of transmitting image signals from the communication interface circuit 4. When the information code printed on the can 34 is inserted into the reading target area of the stationary information code reading device 30, from the same operation as described above, it can be deduced after estimating that the existence probability of the information code is high. it can. As a result, effects equivalent to those of the first and second embodiments can be obtained.

(Fifth Embodiment) FIGS. 18 to 20
Shows a fifth embodiment of the present invention. The difference from the first embodiment is that a two-dimensional image storage memory 40 is provided in place of the bright-dark point number storage memory 17 to provide a two-dimensional image storage. The contents of the memory 14c are stored, the processing contents are further changed, and the processing is applied to the stationary information code reader 1. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described below.

The binarizing circuit 9 functioning as a judging means includes:
When each pixel data of the image picked up by the CCD area sensor 7 is input, it is determined as a bright point, a dark point or a point in a dead zone and output to the two-dimensional image memory 14c. The two-dimensional image memory 14c as a storage unit is configured to store as a pixel light and dark point at an address for each pixel specified by the first address generation circuit 13. The binarization circuit 9
One image area is divided into an inspection area composed of a plurality of areas.

The two-dimensional image memory 14c is connected to a two-dimensional image storage memory 40 as storage means.
It has a storage area of at least the two-dimensional image memory 14c. The two-dimensional image memory 14c is configured so that data stored in the two-dimensional image memory 14c can be transferred inside. The second address generation circuit 18 is connected to the control circuit 8, and specifies the address of the two-dimensional image memory 14c and the address of the two-dimensional image storage memory 40 in correspondence with the control signal from the control circuit 8. It is configured to be possible. The other configuration is substantially the same as that of the first embodiment, and thus the description thereof is omitted.

FIGS. 19 and 20 show the operation of the above configuration.
This will be described with reference to FIG. As shown in FIG. 2, it is assumed that a document B on which a picture or the like is printed exists in a reading target area of the stationary information code reading device 1. FIG. 19 is a flowchart showing the entire operation.

When the stationary information code reader 1 is powered on, an initialization process is performed (step V1). In this case, the second address generation circuit 18 specifies the respective addresses of the two-dimensional image memory 14c and the two-dimensional image storage memory 40 based on the control signal of the control circuit 8, and the control circuit 8 The data for one image area is transferred from the memory 14c to the two-dimensional image storage memory 40. Therefore, data stored in the two-dimensional image memory 14c for one image area corresponding to the image shown in FIG. 5 is transferred to the two-dimensional image storage memory 40 at the same coordinates corresponding to each pixel. become.

Then, image acquisition and binarization processing are performed (step V2). FIG. 20 is a flowchart showing the image acquisition and binarization processing. When the light reflected on the reading target area enters the CCD area sensor 7, the light signal is transmitted to the binarizing circuit 9 and the image data memory in the image memory 14 via the amplifier circuit 11 and the A / D converter circuit 12. 14a (steps W1 and W2). The binarization circuit 9 outputs the pixel data to the two-dimensional image memory 14c as any one of a bright point, a dark point, and a dead zone (step W3).

The control circuit 8 stores the data obtained in steps W2 and W3 in the image data memory 14a, respectively.
And stored in the two-dimensional image memory 14c (step W
4).

Thereafter, the control circuit 8 generates a synchronizing pulse by the synchronizing pulse generation circuit 10, and determines whether data for one image area has been stored in the two-dimensional image memory 14c, the image data memory 14a and the number of bright and dark points memory 14b. It is determined (step W5) whether it is not stored, and if it is not stored, the control circuit 8 causes the synchronization pulse generation circuit 10 to generate a synchronization pulse again (step W6). Then, the control circuit 8 increments the address generated by the first address generation circuit 13 (step W7), and performs the processing of steps W2 to W7 until data for one image area is stored (step W5: Yes). repeat. Control circuit 8
When it is confirmed in step W5 that data for one image area has been stored, the image acquisition and binarization processing ends. In this case, as shown in FIG. 8, if a piece of paper on which the information code P is printed is inserted into the read target area, data for one image area corresponding to the image shown in FIG. The data is stored in the data memory 14a, the number of bright and dark points memory 14b, and the two-dimensional image memory 14c).

Referring back to FIG. 19, the second address generation circuit 1
8, the addresses of the same coordinates in the two-dimensional image memory 14c and the two-dimensional image storage memory 40 are designated (step V3). In this case, an address corresponding to the same pixel in the previous image and the current image is specified.
The control circuit 8 refers to the value stored at the corresponding address, determines whether or not a bright point has changed to a dark point or a dark point to a bright point for each pixel and compares them (step V).
4).

If the control circuit 8 determines that the pixel has a change in the determination result of the pixel bright / dark point as a result of the comparison (step V4: Yes), the control circuit 8 is provided corresponding to the plurality of inspection areas. The change number counter for the inspection area is added and counted (step V5). The information on the plurality of inspection areas is transmitted from the binarization circuit 9 in advance.

If the control circuit 8 determines in step V4 that the pixel is not a pixel having a change in the determination result (step V4: No), the process proceeds to step V5.
Then, the process shifts to step V6.

Here, the control circuit 8 determines whether or not the data comparison for one inspection area has been completed based on the control signal for the second address generation circuit 18 (step V).
6) If the data comparison for one inspection area has not been completed, the address generated by the second address generation circuit 18 is changed (step V7), and the other pixel data in the same inspection area as the previously referenced inspection area is changed. See And
Steps V3 to V7 are repeated, and if the data comparison for one inspection area is completed in step V6 (step V6: Yes), the control circuit 8 determines that the number of pixels that have changed between the previous image and the current image is Is determined. Note that this judgment point is set in advance, and may be set to a different value for each inspection area,
The same value may be set in all inspection areas.

Then, the control circuit 8 counts the number of inspection areas which have exceeded the number of determination points among the inspection areas determined so far (step V8). Then, it is determined whether or not the counted number of inspection areas exceeds a predetermined number of determination areas (step V9).

For example, if the number of inspected inspection areas does not reach the number of determination areas and is small, it is determined No in step V9. In addition, even if the number of inspected inspection areas is large, if the number of pixels changed in the inspection area is small and the number of target inspection areas exceeding the number of judgment points is small, No is determined in step V9.

In this case, the control circuit 8 determines whether or not the data comparison for one image area has been completed, that is, whether or not the data comparison has been completed for all inspection areas (step V10). If the data comparison for one image area has not been completed (step V10: No), the second address generation circuit 18 changes the address to a storage area corresponding to another inspection area for which the inspection has not been completed (step V10). V11),
The control circuit 8 clears the change number counter for the inspection area, and repeats steps V3 to V11 again. In the course of performing the repetitive processing, the control circuit 8 executes step V1
If it is determined in step V9 that the number of inspection zones exceeds the number of determination zones before it is determined in S0 that the data comparison for one image region has been completed, the data in the two-dimensional image memory is stored in the two-dimensional image memory. The data is transferred to and stored in the storage memory, and it is estimated that the probability that the information code P exists in the read target area is high, and the decoding process is performed (steps V12 to V1).
3).

That is, if it is determined to be Yes in step V9 immediately before the data comparison for one image area is completed, or if only a part of all the inspection areas for one image area is determined, step S9 is performed. Even if Yes is determined in V9, the decryption processing is performed.

In such a case, the order of the inspection areas determined in steps V3 to V7 contributes to improving the processing speed for shifting to the decoding processing. On the other hand, the determination may be started in order from the inspection area corresponding to the substantially central part, or may be started in order from the inspection area corresponding to the end part with respect to the entire inspection area.

As a specific example, it is assumed that a piece of paper on which the information code P is printed as shown in FIG. 8 is inserted from the state shown in FIG. 2 and an image is taken as shown in FIG. Control circuit 8
The inspection area to be inspected moves sequentially from the upper left part to the upper right part of the first step in FIG. 9, and further moves from the upper left part to the upper right part of the second step, and similarly from the third step to the seventh step. Suppose that it was set to move. In this case, for example, it is assumed that the number of determination points is set so as not to change for each inspection area (the total number of pixels in one inspection area is 100), and the number of determination areas is set to, for example, six. Further, the fourth row, the fifth row, the sixth row, the second row, the fourth row, the fifth row, and the sixth row of the inspection area corresponding to the inspection area where the information code P is imaged are: It is assumed that it is determined that the inspection area sequentially exceeds the determination score, and that the fourth row of the third row is determined to exceed the determination score. In this case, the control circuit 8 determines that the counted number of inspection areas is seven, and thus determines that the number of inspection areas exceeds the number of determination areas, and shifts to the decoding process without determining other inspection areas.

When a large area, such as a symbol, having a large area and an unclear brightness is inserted into the reading target area, two consecutive images stored in the two-dimensional image storage memory 40 and the two-dimensional image memory 14c are read. The difference in brightness of the same pixel for each inspection area in the region is reduced. Therefore, if the number of determination zones is adjusted in advance, even when a symbol or other unclear image such as a symbol is inserted into the reading target region at the time of estimating the presence of the information code in the reading target region, the process proceeds to the decoding process. Probability is lower.

Returning to the description of FIG. 19, even if the data comparison for one image area is completed, the determination in step V9 is No.
Is determined, the control circuit 8 determines Yes in step V10. The control circuit 8 transfers the data of the two-dimensional image memory 14c to the two-dimensional image storage memory 40 for storage (step V14). In this case, the content stored in the two-dimensional image memory 14c is overwritten in the two-dimensional image storage memory 40 corresponding to each pixel. Then, the control circuit 8 clears the counted number of inspection areas. Further, the processing of steps V2 to V14 is repeated again. In this case, the CCD area sensor 7 captures an image of the reading target area every predetermined period, and the processing is performed.
Others are substantially the same as the description in the above-described embodiment, and thus the description is omitted.

According to the fifth embodiment, the number of pixels having a change between the pixel bright and dark points of the previous image and the determination result of the current image is counted by the search area change number counter for each inspection area. When the value of the counter exceeds a predetermined determination point, the inspection area is counted, and it is determined that the counted number exceeds the determination area number by the time the data comparison for one image area is completed. Then, it can be estimated that the probability that the information code exists in the read target area is high, and the process shifts to the decoding process to decode the information code P.

(Sixth Embodiment) FIG. 21 shows a sixth embodiment of the present invention. The difference from the fifth embodiment is that data comparison is not performed for each inspection area. This is to compare pixel data in units of one image area. Hereinafter, processing performed by the stationary information code reader 1 will be described.

As in the fifth embodiment, it is assumed that the document B exists in the reading target area as shown in FIG. FIG.
1 is a flowchart showing the entire operation. When the stationary information code reader 1 is powered on,
The initialization processing is performed in the same manner as described in the first embodiment, and the image acquisition and binarization processing are performed (steps X1 and X2). In this case, data for one image area corresponding to the image shown in FIG. 5 is stored in the two-dimensional image memory 14c, and data for one image area corresponding to the image shown in FIG. Data memory 14a, light / dark point number memory 14
b, stored in the two-dimensional image memory 14c).

Thereafter, the second address generation circuit 18 specifies the addresses of the same coordinates in the two-dimensional image memory 14c and the two-dimensional image storage memory 40 (step X).
3). In this case, an address corresponding to the same pixel in the previous image and the current image is specified. The control circuit 8
With reference to the value stored at the corresponding address, it is determined for each pixel whether or not a change has occurred from a bright point to a dark point or from a dark point to a bright point (step X4).

When the control circuit 8 determines that the pixel has a change in the determination result of the pixel bright / dark point as a result of the comparison (step X4: Yes), the control circuit 8 adds and counts a change number counter (step X4). If X5) has not changed, the change counter is not added.

If the data comparison for one image area has not been completed (step X6: No), the control circuit 8 changes the address (step X7) and repeats the processing of steps X3 to X7. In step X6, the control circuit 8
When judging the end of the data comparison for the image area, the control circuit 8 transfers the data for one image area stored in the two-dimensional image memory 14c to the two-dimensional image storage memory 40 for storage (step X8).

In this case, the control circuit 8 determines whether or not the number-of-changes counter has exceeded the number of determination points (step X).
9). This judgment point is set in advance. When the control circuit 8 determines that the number-of-changes counter has exceeded the determination point, it performs a decoding process (step X1).
0). Other features are substantially the same as those of the fifth embodiment and the like, and therefore, description thereof is omitted.

According to the sixth embodiment, when the control circuit 8 determines that the number of pixel points changed between the previous image and the current image (change number counter) exceeds the judgment point,
Since it is estimated that the probability that the information code exists in the read target area is high, the processing can be simplified as compared with the configuration shown in the fifth embodiment.

(Other Embodiments) The present invention is not limited to the above-described embodiments, but may take various forms as long as they fall within the technical scope of the present invention. In particular, the stationary information code readers 1, 20, 3 according to the above-described embodiments.
0 is a stationary type, but the present invention is not limited to the stationary type and may be applied to a portable (handy type) information code reader.

In the above-described embodiment, the switch group 15 may be provided as needed, and the sensitivity (setting of the number of determination zones) can be automatically adjusted by the control circuit 8. Further, the information code is not limited to the information code shown in the above-described embodiment, and can be applied to an information code reading device capable of reading an information code having a light and dark pattern as shown in FIGS. 17 (a) to 17 (d). It is.

In the above-described embodiment, the description has been made by setting the luminance range within the dead zone. However, the luminance range within the dead zone may be provided as needed.

In the above-described embodiment, when the decoding process is performed, the LED is turned on to read again, and the decoding process is performed. However, there is a case where it is not necessary to turn on the LED depending on the surrounding situation such as when the surroundings are bright. In this case, decoding can be performed without having to read again.

The binarizing circuit 9 is provided so as to function as a counting means, and as described in the above embodiment, after judging the bright and dark points of the pixel data, the number is counted (counting process). You may. In this case, the two-dimensional image memory 14c is provided so as to function as a storage means, and the counted number is stored as a light and dark number (storage process), and the counted light and dark number is stored in the previous image taken at predetermined intervals. In the comparison with the current image, the control circuit 8 may be configured to estimate that the probability that the information code P exists in the read target area is higher when the number exceeds the predetermined number (estimation process). In this case, the number of light and shade of the previous image is stored in the two-dimensional image storage memory 40.

The information code existence estimating program stored in the control circuit 8 may be stored in a storage medium such as a hard disk or a CDROM, and may be distributed.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram of an information code reading device according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of the overall configuration.

FIG. 3 is an explanatory diagram showing a luminance range for determining a bright point and a dark point in principle;

FIG. 4 is a flowchart showing an operation of storing data for one image area in an image memory;

FIG. 5 is a diagram schematically showing a state where an image of a reading target area is imaged and an inspection area;

FIG. 6 shows (a) the contents of a memory for the number of bright and dark points and (b) the structure of the corresponding address and data in one image area divided into inspection areas before a document on which an information code is printed is inserted. Figure showing

FIG. 7 is a flowchart showing the operation when estimating the presence of an information code;

FIG. 8 is a diagram showing a state when a paper piece on which an information code is printed is inserted;

FIG. 9 is a diagram schematically showing a state where an image is printed from a reading target area and an inspection area when a paper piece on which an information code is printed is inserted;

FIG. 10 is a diagram showing (a) the contents of a light / dark point number memory and (b) the corresponding address and data structure when a paper piece on which an information code is printed is inserted.

11A is a diagram illustrating a result of a subtraction comparison, and FIG. 11B is a diagram illustrating a structure of a corresponding address and data.

FIG. 12 is a flowchart showing an operation at the time of decoding.

FIG. 13 is a view corresponding to FIG. 4, showing a second embodiment of the present invention;

FIG. 14 is a diagram corresponding to FIG. 7;

FIG. 15 is a view corresponding to FIG. 8, showing a third embodiment of the present invention;

FIG. 16 is a view corresponding to FIG. 8, showing a fourth embodiment of the present invention;

FIG. 17 shows an example of an information code.

FIG. 18 is a view corresponding to FIG. 1, showing a fifth embodiment of the present invention;

FIG. 19 is a flowchart showing an operation.

FIG. 20 is a flowchart showing image acquisition and binarization processing;

FIG. 21 is a view corresponding to FIG. 19, showing a sixth embodiment of the present invention;

[Explanation of symbols]

1, 20 and 30 are stationary information code readers (information code readers), 7 is a CCD area sensor (imaging means),
8 is a control circuit (control means), 9 is a binarizing circuit (light / dark judgment means, judgment means), 14b is a light / dark point number memory (judgment storage means), 14c is a two-dimensional image memory (storage means),
Reference numeral 17 denotes a memory for storing the number of light and dark points, and reference numeral 40 denotes a memory for storing a two-dimensional image.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5B072 CC21 DD01 DD16 DD21 LL13 LL19

Claims (13)

[Claims] An imaging step of imaging a read target area at predetermined time intervals, and determining a bright point and a dark point for each pixel data of the image of the read target area obtained by the imaging step, A light-dark determination step of scanning a pixel in a predetermined direction to determine a pixel changing from a bright point to a dark point or a pixel changing from a dark point to a bright point between adjacent pixels; and determining the image in the light-dark determination step. A determination result storing step of storing the obtained result as the number of light and dark points, and comparing the determination result in the light and dark point determination step with the number of light and dark points stored for the previous image captured in the imaging step, and changing to the number of light and dark points. A light-dark point change counting step of counting the number of pixels in which the number of pixels having occurred, and when the number of pixels counted in the light-dark point change counting step exceeds a predetermined judgment point, Information code exists estimation method characterized by having an estimating step of estimating a higher probability that the information code consisting of a dark pattern is present. 2. An image capturing step of capturing an image of a read target area at predetermined time intervals; a dividing step of dividing an image of the read target area captured by the image capturing step into a plurality of inspection areas; The pixel data of the image of the image to be read is determined as a bright point or a dark point, and the pixels of the image are scanned in a predetermined direction to change a pixel or a dark point between adjacent pixels. A light / dark judgment step of judging a pixel changing from a light point to a light point; a judgment result storing step of storing a result judged for the image in the light / dark judgment step as the number of light / dark points for each of the plurality of inspection areas; The determination result in the process and the number of light and dark points stored for the previous image captured in the imaging process are compared for each of the plurality of inspection areas, and the number of pixels having a change in the number of light and dark points is counted. The number of the inspection areas is counted when the number of the pixels counted in the light-dark point change counting step exceeds a predetermined judgment point number. An estimation step of estimating that the probability that an information code composed of a light and dark pattern is present in the read target area when the number of areas exceeds a predetermined determination area is high. 3. The information code existence estimating method according to claim 2, wherein the number of the determination zones in the estimating step can be set to different values. 4. An image pickup means for picking up an image of a read-out area every predetermined period, and determining a bright point and a dark point for each pixel data of the image of the read-out area obtained by this image pickup means. A light-dark determining means for scanning a pixel in a predetermined direction to determine a pixel changing from a bright point to a dark point or a pixel changing from a dark point to a bright point between adjacent pixels; and determining the image by the light-dark determining means. Determination result storage means for storing the result obtained as the number of light and dark points; comparing the determination result of the determination result storage means with the number of light and dark points stored for the previous image captured by the imaging means; Control means for estimating that there is a high probability that an information code composed of a light-dark pattern exists in the read target area when the number of generated pixels exceeds a predetermined number of judgment points. An information code reader characterized by the above-mentioned. 5. An image pickup means for picking up an image of a read-out area every predetermined period, and determining a bright point and a dark point for each pixel data of the image of the read-out area obtained by the image pickup means. A pixel scanning in a predetermined direction to determine a pixel that changes from a bright point to a dark point or a pixel that changes from a dark point to a bright point between adjacent pixels; A determination result storage unit that stores the obtained result as the number of light and dark points for each of a plurality of inspection areas; and the determination result of the light and dark determination unit and the number of light and dark points stored for the previous image captured in the imaging process. Compared for each inspection area, when the number of pixels for each inspection area where the number of light and dark points has changed exceeds a predetermined judgment point, the number of the inspection areas is counted, and the counted inspection area is counted. Number An information code reading device, comprising: control means for estimating that the probability that an information code composed of a light and dark pattern exists in the read target area is high when the number exceeds a predetermined number of determination zones. 6. The information code reading device according to claim 5, wherein the control means can set the number of the determination zones for the estimation to different values. 7. An information code existence estimating program for causing a computer to execute an imaging step, a light / dark judgment step, a judgment result storage step, a light / dark point change counting step, and an estimation step according to claim 1. 8. An information code existence estimating program for causing a computer to execute an imaging step, a dividing step, a light / dark judgment step, a judgment result storing step, a light / dark point change counting step and an estimating step according to claim 2 or 3. 9. An image capturing step of capturing an image of the read target area at predetermined time intervals; a determining step of determining a bright point and a dark point for each pixel data of the image of the read target area obtained by the image capturing step; A storage step of storing a result determined for the image in the determination step as a pixel light and dark point; and a determination result in the determination step and a pixel light and dark point stored for a previous image captured in the imaging step. A counting process of comparing each pixel and counting the number of pixels in which the determination result of the pixel bright / dark point has changed, and a case where the number of pixels counted in the counting process exceeds a predetermined determination score. Estimating that there is a high probability that an information code composed of a light and dark pattern exists in the read target area. 10. An image capturing step of capturing an image of a read target area at predetermined intervals, a dividing step of dividing an image of the read target area captured by the image capturing step into a plurality of inspection areas, Determining a bright point and a dark point for each pixel data of the image of the read target area, storing a result determined for the image in the determination step as a pixel bright and dark point, The determination result in the process and the pixel light and dark points stored for the previous image captured in the image capturing process are compared for each pixel, and the number of pixels having a change in the pixel light and dark point determination result is determined by the plurality of pixels. A counting step of counting for each inspection area, and counting the number of inspection areas when the number of pixels for each inspection area counted in the counting step exceeds a predetermined judgment point. Estimating that the probability that an information code composed of a light and dark pattern exists in the read target area when the number of inspection areas exceeds a predetermined number of determination areas is high. . 11. An imaging step of imaging a read target area at predetermined time intervals, and in a state where a bright point or a dark point is determined for pixel data of an image of the read target area imaged in the image capture step, A counting step of counting the number of bright spots or dark spots; a storing step of storing the result counted for the image in the counting step as a bright / dark number; a counting result in the counting step and an image taken in the imaging step Comparing the number of light and dark stored with respect to the previous image, and presume that when the change in the number of light and dark exceeds a predetermined number, there is a high probability that an information code composed of a light and dark pattern exists in the read target area. An information code presence estimating method, comprising: 12. An image pickup means for picking up an image of the read target area at predetermined time intervals, a determination means for determining a bright point and a dark point for each pixel data of the image of the read target area obtained by the image pickup means. A storage unit that stores the result determined for the image by the determination unit as a pixel light and dark point; and a pixel that stores the determination result of the determination unit and the pixel light and dark point stored for the previous image captured in the imaging process. Each time, the number of pixels having a change in the determination result is counted, and when the counted number of pixels exceeds a predetermined determination point, an information code consisting of a light and dark pattern in the read target area. And a control means for estimating that the probability of existence of the information code is high. 13. An image pickup means for picking up an image of a read target area at predetermined time intervals; a dividing step of dividing the image of the read target area obtained by the image pickup means into a plurality of inspection zones; Determining means for determining a light point and a dark point for each pixel data of the image of the image of the reading target area; storage means for storing a result determined for the image by the determining means as a pixel light and dark point; Comparing the result of the determination by the means with the pixel light and dark points stored for the previous image captured by the image capturing means for each pixel, and determining the number of pixels having a change in the result of the determination of the pixel light and dark points by the plurality of pixels. Is counted for each inspection area, and when the counted number of pixels for each inspection area exceeds a predetermined judgment point, the number of the inspection areas is counted. Number of areas Information code reading apparatus characterized by a control means for estimating a higher probability that the information code consisting of light and dark pattern is present during said reading target area when exceeding.