JP2000040121A - Code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a user able to automatically perform read in an optimum state just by bringing a reader closer to a code without being conscious of a focus position. SOLUTION: This code reader is provided with a transition degree detection means S1 for detecting the transition degree on a specified scanning line of multi-valued image data converted by a multi-valued image data conversion circuit provided in an area sensor unit and further a focus position judgement means for judging that a code read position is at the focus position in the case of detecting that the transition degree on the specified scanning line of the multi-valued image data detected by the transition degree detection means S1 is equal to or more than a stipulated value and judging that the code read position is not at the focus position in the case of judging that the transition degree on the specified scanning line of the multi-valued image data detected by the transition degree detection means S1 is smaller than the stipulated value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code reader for reading a two-dimensional code or the like, such as a handy type two-dimensional code reader.

[0002]

2. Description of the Related Art A conventional code reading apparatus will be described with reference to FIGS. In FIG.
11 is a code reading device, 12 is a code reading device main body, 13 is an interface cable connected to the code reading device main body 12, 14 is a reading port provided at the front end of the device main body 12, and 15 is a button for starting a reading operation. Is a result notifying LED for notifying the reading result, and 17 is a two-dimensional code as a reading code printed on a reading label 18.

The two-dimensional code 17 is irradiated with light through the reading opening 14 and the reflected light is taken into the apparatus main body 12 through the reading opening 14.

In the apparatus main body 12, for example, CC
The reflected light is received by the imaging means by the D area sensor.

When a user reads a two-dimensional code, first, the reading opening 14 is turned to the two-dimensional code 17 printed on the reading label 18. Then, the reading operation is started by pressing the trigger switch 15.

When the reading is successful, the LED 16
Lights up, and data is transferred to the host computer via the interface cable 13.

In the conventional code reading device 11, a reading operation is performed by first to fourth processes as shown in flowcharts of FIGS.

First, as shown in a flowchart (first reading process) of FIG. 16, it is determined whether or not the trigger switch 15 has been pressed. When it is determined that the trigger switch 15 has been pressed, reading is started. Then, if the reading is successful, the reading result is transferred to the host computer, and the system is in a state of waiting for the next trigger switch 15 to be pressed.

As shown in a flowchart (second reading process) of FIG. 17, it is determined whether or not the trigger switch 15 has been pressed. If it is determined that the trigger switch 15 has been pressed, reading is performed. When the reading is successful, the reading result is transferred to the host computer and a trigger wait state is set.

On the other hand, if the reading is not successful,
If reading has been performed a predetermined number of times, a trigger wait state is maintained. If reading has not been performed a predetermined number of times, a reading operation is continuously performed.

Further, as shown in the flowchart of FIG. 18 (third reading process), it is determined whether or not the trigger switch 15 has been pressed. When it is determined that the trigger switch 15 has been pressed, reading is started. If successful, the read result is transferred to the host computer, and the apparatus is directly in a trigger waiting state.

By the way, if the reading is not successful, if the trigger switch 15 is not kept pressed,
The trigger wait state is kept as it is, and if the trigger switch 15 is kept pressed, the reading process is continuously performed.

Further, as shown in a flowchart (fourth reading process) of FIG. 19, reading is started irrespective of the trigger switch 15, and when reading is successful, the reading result is transferred to the host computer. If the reading is not successful, the reading is continued.

[0014]

In the above-described first to third reading processes, reading is performed at the timing when the trigger switch 15 specified by the user is pressed.
As described above, since the user designates the reading timing, the user designates the reading timing of the reading device, so that the user always needs to be aware of the appropriate focal position of the reading device.

In the fourth reading process, since the image data is fetched continuously, the user does not need to be aware of the fetch timing. However, when the image is out of focus, the code image is fetched and decoded. If this is done, there is a problem that the reading probability is lowered because the code quality is lower than usual.

If the code includes an error correction code such as a two-dimensional code, the time for performing the error correction is delayed, so that the user feels that reading is slow.

The present invention has been made in view of the above points, and a purpose thereof is to automatically perform reading in an optimum state simply by moving a reader close to a code without being conscious of a focus position. It is an object of the present invention to provide a code reading device capable of performing the above.

[0018]

According to a first aspect of the present invention, there is provided a code reading apparatus for irradiating a symbol on a print medium with light and outputting an amount of electricity corresponding to the amount of light received from the symbol. And a multi-valued image data conversion means for converting image data output from the imaging means into multi-valued image data, and Transition degree detecting means for detecting the transition degree of a specific scan line of the multi-valued image data, and when the transition degree of the multi-valued image data detected by the specific scan line is greater than or equal to a specified value If detected, the code reading device determines that it is at the focus position, and the multi-valued image detected by the transition degree detecting means is detected. If the transition degree of a particular scan line of data is determined to be smaller than the prescribed value, characterized in that the code reading device is provided with a with determining the focus position determination unit is not in focus position.

According to a second aspect of the present invention, there is provided a code reading apparatus, comprising: a photoelectric conversion element configured to irradiate a symbol on a print medium with light and to output an electric quantity corresponding to an amount of light received from the symbol. In a code reading device comprising: a multi-valued image data conversion means for converting the image data output from the imaging means to multi-valued image data,
A transition amount detecting means for detecting a transition amount of the multi-valued image data converted by the multi-valued image data converting means on a specific scan line; and a specific scan line of the multi-valued image data detected by the transition amount detecting means. When it is detected that the transition amount is equal to or greater than the set value, the code reading device determines that the focus position is at the focus position, and determines whether or not the multi-valued image data detected by the transition amount detection means is in a specific scan line. When the transition amount is determined to be smaller than the set value, the code reading device includes a focus position determining unit that determines that the focus position is not at the focus position.

According to a third aspect of the present invention, there is provided a code reading device, comprising: a photoelectric conversion element configured to irradiate a symbol on a print medium with light and output an electric quantity corresponding to an amount of light received from the symbol. In the code reading device, the transition degree detecting means for detecting the transition degree of the analog image signal output from the imaging means, and the transition degree of the analog image signal detected by the transition degree detecting means is a specified value or more Is detected, the code reading device determines that the focus position, and when it is determined that the transition degree of the analog image signal detected by the transition degree detection means is smaller than a specified value, Is characterized in that the code reading device is provided with a focus position determining means for determining that the code position is not at the focus position.

According to a fourth aspect of the present invention, there is provided a code reading device, comprising: a photoelectric conversion element configured to irradiate a symbol on a print medium with light and output an electric quantity corresponding to an amount of light received from the symbol. A transition amount detecting means for detecting a transition amount of the analog image signal output from the imaging means, and a transition amount of the analog image signal detected by the transition amount detecting means being equal to or more than a set value. Is detected, the code reading device determines that the focus position is present, and when it is determined that the transition amount of the analog image signal detected by the transition amount detection means is smaller than a set value, Is characterized in that the code reading device is provided with a focus position determining means for determining that the code position is not at the focus position.

According to a fifth aspect of the present invention, there is provided a code reading device, wherein the focus position determining means according to any one of the first to fourth aspects determines that the code reading device is at a focus position. Means for starting a reading operation by the code reading device.

According to a sixth aspect of the present invention, there is provided a code reading apparatus including a display unit provided in the code reading apparatus, wherein the code reading apparatus is provided by the focus position determining unit according to any one of the first to fourth aspects. Means for illuminating the display means when it is determined that the camera is at the focus position.

According to a seventh aspect of the present invention, there is provided a code reading apparatus comprising: a sound emitting means provided in the code reading apparatus; and a focus position determining means according to any one of the first to fourth aspects. Means for driving the sounding means when it is determined that the camera is at the focus position.

According to an eighth aspect of the present invention, there is provided a code reading apparatus, comprising: a vibration device provided in the code reading apparatus; and a focus position determining unit according to any one of the first to fourth aspects, wherein the code reading apparatus is focused. Means for driving the vibration device when it is determined that the vibration device is located at the position.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;
An embodiment will be described. In FIG. 1, 21 is a code reading device, 22 is a code reading device main body,
23 is an interface cable connected to the code reading device main body 22, 24 is a reading port provided at the front end of the device main body 22, 25 is a trigger switch for starting a reading operation, and 26 is a notification switch for notifying a reading result. The result notification LED 27 is an LE for notifying focus information.
D and 28 are two-dimensional codes as read codes printed on a read label 29.

The two-dimensional code 27 is irradiated with light through the reading port 24, and the reflected light is taken into the apparatus main body 22 through the reading port 24.

In the apparatus main body 22, for example, CC
The reflected light is received by the imaging means by the D area sensor.

Next, an electric circuit mounted on the apparatus main body 22 will be described with reference to FIG. In FIG.
31 is an area sensor unit. The area sensor unit 31 has an area sensor composed of, for example, a CCD of 800 × 600 pixels.

The area sensor unit 31 further includes a drive circuit for driving the area sensor, a counter for counting coordinate values based on the drive timing from the drive circuit, and an amplifier for amplifying an image signal from the area sensor. A multivalued image data conversion circuit is provided which has a circuit and a shading correction function, and converts an image signal amplified by the amplifier circuit into, for example, 8-bit multivalued image data.

The multi-valued image data output from the area sensor unit 31 is stored in a DMA (direct memory acces
s) 32.

Reference numeral 33 denotes a CPU (Central Processing Unit) that controls the code reader 21 in an integrated manner.

A program bus 35, an image memory 36, a DMA3
2. Communication interface 37, I / O (Input / Output)
Port 38 is connected.

The I / O port 38 has a target 3
9, an illumination 40, a trigger switch 25, an external trigger switch 41, a display 42 which is an LED 26 and an LED 27, for example, a sound generator 43 composed of a buzzer, and a vibrator 44 are connected.

The program memory 35 stores a program for performing the processing shown in the flowcharts of FIGS.

Next, the operation of the first embodiment of the present invention configured as described above will be described. The operator holds the apparatus main body 22, reads the reading port 24, and reads the label 2
9 is moved so as to approach a two-dimensional code as shown in FIG.

Then, the light emitted from the illumination 40 is applied to the reading label 29 through the reading port 24. Then, the reflected light reflected by the reading label 29 is read by the reading port 2.
4 and is taken into the apparatus main body 22.

The reflected light is picked up by an area sensor provided in the area sensor unit 31.

Then, the two-dimensional code imaged by the area sensor is changed to multi-valued image data by a multi-valued image data conversion circuit.

Here, the multi-valued image data represents the brightness of a two-dimensional code captured by the area sensor as 8-bit image data (256 gradations).

The 8-bit multivalued image data is transferred to the image memory 36 under the control of the DMA 32.

Accordingly, the image memory 36 stores multi-dimensional image data of a two-dimensional code. Here, among the multi-valued image data of the two-dimensional code stored in the image memory 36, the multi-valued image data of the scan line of interest is shown in FIGS. The multi-valued image data of FIG. 7 shows the case where the code reader 21 is in focus, and the multi-valued image data of FIG. 8 shows the case where the code reader 21 is out of focus.

Hereinafter, the processing shown in the flowchart of FIG. 4 is performed using the multi-valued image data of FIG. 7 or FIG.

That is, the degree of change when the multi-valued image data stored in the image memory 36 changes to black and white is totalized by the recognition program (step S1). This recognition program is a program stored in the program memory 35. This recognition program tabulates the degree of change when the multivalued image data shown in FIG. 7 changes from a white portion 7a to a black portion 7b. As shown in FIG. 7, when the subject is in focus, the change from the white portion 7a to the black portion 7b is steep, so that the degree of change is larger than the specified value.

On the other hand, when the degree of change is calculated by the recognition program for the multi-valued image data as shown in FIG. 8 which is out of focus, even if the white part 7a changes to the black part 7b, the focus is achieved. Therefore, the multi-valued image data changes slowly. For this reason, even if the change degree when changing from the white portion 7a to the black portion 7b is calculated by the recognition program, the change degree is smaller than the specified value.

Therefore, if the degree of fluctuation is greater than the specified value (step S2) (step S2), if the image is in focus as in the multi-valued image data shown in FIG. Is recognized by the CPU 33 as an image matching (step S3).

When recognized by the CPU 33 in this way, the LED 27 is turned on to notify that focus has been achieved.

On the other hand, if the image is out of focus as in the multi-valued image data of FIG. 8, the determination is "NO" and the CPU 33 recognizes the image as out of focus (step S4).

As described above, the fact that the object is in focus is C.
When recognized by the PU 33, the reading process is automatically started by the process shown in the flowchart of FIG.

That is, in FIG. 6, it is determined whether focus is achieved (step S21). This step S
The determination of 21 uses the determination results of steps S3 and S4 in FIG.

Then, in the determination in step S21, "Y
If it is determined to be "ES", reading for performing decoding processing based on the multi-valued image data stored in the image memory 36 is started (step S22).

Then, it is determined whether the reading process started in step S22 is successful (step S23).

If "YES" is determined in step S23, the LED 26 is turned on to notify that the reading has been successful. Further, the read result is transferred to the host computer via the interface cable 23.

As described above, when the image is in focus, the reading process is automatically started, so that it is not necessary to press the trigger switch as in the prior art, thereby improving the operability of the code reader. Can be.

Next, a second embodiment of the present invention will be described with reference to the flowchart of FIG. In the flowchart of FIG. 4 described above, the degree of change when the multi-valued image data stored in the image memory 36 changes from the white portion 7a to the black portion 7b is tabulated. -In the chart, the transition amount is totaled. Here, the degree of change corresponds to the rate of change of the multi-valued image data, and the amount of transition corresponds to the difference between the absolute values of the multi-valued image data.

Next, the operation of the second embodiment will be described with reference to the flowchart of FIG.

That is, the amount of transition when the multivalued image data stored in the image memory 36 changes to black and white is totalized by the recognition program (step S11). This recognition program is a program stored in the program memory 35. This recognition program tabulates the transition amounts when the multivalued image data shown in FIG. 7 changes from the white portion 7a to the black portion 7b. As shown in FIG. 7, when the image is in focus, the change from the white portion 7a to the black portion 7b is large, and the transition amount is larger than the set value.

On the other hand, when the amount of transition is counted by the recognition program for multi-valued image data as shown in FIG.
Even if it changes to b, the multi-valued image data changes gently because it is out of focus. Therefore, even if the amount of transition when changing from the white portion 7a to the black portion 7b is tabulated by the recognition program, the amount of transition is smaller than the set value.

Accordingly, if the focus is determined as in the multi-valued image data of FIG. 7 with respect to the determination of "transition amount> set value" (step S12), it is determined to be "YES" and the focus is determined. Is recognized by the CPU 33 as an image matching (step S13).

When the recognition is made by the CPU 33, the LED 27 is turned on to notify that focus has been achieved.

On the other hand, if the image is out of focus as in the multi-valued image data of FIG. 8, the determination is "NO" and the CPU 33 recognizes the image as out of focus (step S14).

As described above, it is determined that the object is in focus.
When recognized by the PU 33, the reading process is automatically started by the process shown in the flowchart of FIG.

As described above, when focus is achieved, the reading process is automatically started, so that it is not necessary to press a trigger switch as in the prior art, thereby improving the operability of the code reader. Can be.

Next, a third embodiment of the present invention will be described with reference to FIGS.

First, the waveform diagrams of FIGS. 10 and 11 will be briefly described. FIG. 10 is an analog waveform diagram of a code read at a focused position. The waveform diagram of FIG. 10 is an output waveform diagram of the area sensor when white, black, and white data appear at equal intervals.

FIG. 11 is an analog waveform diagram of a code read at an out-of-focus position. The waveform diagram of FIG. 11 is an output waveform diagram of the area sensor when white, black, and white data appear at equal intervals. Since the focus is not adjusted, the boundary between white and black has a smooth data fluctuation. ,
Moreover, the difference between the absolute values of white and black is low.

FIG. 9 is a block diagram showing a main part of the third embodiment in which an analog image signal output from an area sensor provided in the area sensor unit 31 is input as an input signal.

In FIG. 9, reference numeral 51 denotes a differentiating circuit for differentiating an analog image signal. The differentiating circuit 51 detects the degree of change (gradient) between black and white.

The maximum value and the minimum value of the degree of change detected by the differentiating circuit 51 are held by the peak hold circuit 52. Then, the CPU 52 compares the maximum value and the minimum value of the degree of variation held in the peak hold circuit 52 with the specified value, and if the value exceeds the specified value, determines that the image is in focus, and determines that the image is in focus. If so, it is determined that the image is out of focus. That is, when the waveform of FIG. 10 is differentiated by the differentiating circuit 51, the waveform shown in FIG. 12 is obtained, and when the waveform of FIG. 11 is differentiated by the differentiating circuit 51, the waveform shown in FIG. 13 is obtained.

Thereafter, the same processing as in the above-described flowchart of FIG. 6 is performed, and when the focus is achieved, the LED 2 is turned on.
7 is turned on and the reading process is automatically started, so that the operability of the code reader can be improved.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, an analog image signal output from the area sensor is input to the peak hold circuit 61 as an input signal. This peak hold circuit 61 holds the maximum value and the minimum value of the analog image signal output from the area sensor.

Then, the CPU 33 compares the maximum value and the minimum value of the analog image signal with the set value, and if the values exceed the set value, it is determined that the camera is in focus, and the value falls below the set value. In this case, it is determined that the subject is out of focus.

Thereafter, the same processing as in the above-described flowchart of FIG. 6 is performed.
Since the reading process is automatically started by turning on D27, the operability of the code reader can be improved.

In the above-described embodiment, the LED 27 is turned on when the code reader is in focus. However, a sound may be emitted from a sound generator (buzzer) 43 and the vibrator 44 may be vibrated. You may make it do.

[0075]

According to the first aspect of the present invention, it is possible to reliably determine whether the code reader is in focus or not.

According to the second aspect of the present invention, it is possible to reliably determine whether the code reader is in focus or not.

According to the third aspect of the present invention, it is possible to reliably determine whether the code reader is in focus or not.

According to the fourth aspect of the present invention, it is possible to reliably determine whether the code reader is in focus or not.

According to the fifth aspect of the invention, when the code reader is in focus, the reading operation is automatically started, so that the reading operation can be performed without operating the trigger switch. And operability can be improved.

According to the sixth aspect of the present invention, when the code reader is in focus, the display means is turned on, so that the user can visually recognize that the focus has been achieved.

According to the seventh aspect of the present invention, when the code reader is in focus, a sound is generated by the sounding means, so that the user can confirm that the focus has been achieved by sound. Can be.

According to the eighth aspect of the present invention, when the code reader is in focus, the vibration device is caused to vibrate, so that the user can be informed of the focus by vibration.

[Brief description of the drawings]

FIG. 1 is an external view of a code reading device according to a first embodiment of the present invention.

FIG. 2 is an exemplary view showing a two-dimensional code according to the embodiment;

FIG. 3 is a control circuit diagram mounted in the code reader.

FIG. 4 is a flowchart for explaining the operation of the first embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the second embodiment of the present invention.

FIG. 6 is a flowchart for explaining an automatic reading process common to the operations of the first to fourth embodiments of the present invention;
G.

FIG. 7 is a diagram showing multi-level image data of a specific scan line among multi-level image data stored in an image memory.

FIG. 8 is a diagram showing multi-level image data of a specific scan line among multi-level image data stored in an image memory.

FIG. 9 is a main part circuit diagram according to a third embodiment of the present invention.

FIG. 10 is a diagram showing an analog image signal output from an area sensor.

FIG. 11 is a diagram showing an analog image signal output from an area sensor.

FIG. 12 is a differential waveform diagram of the analog image signal of FIG.

FIG. 13 is a differential waveform diagram of the analog image signal of FIG.

FIG. 14 is a main part circuit diagram according to a fourth embodiment of the present invention.

FIG. 15 is an external view of a conventional code reader.

FIG. 16 is a flowchart for explaining a conventional reading operation.

FIG. 17 is a flowchart for explaining a conventional reading operation.

FIG. 18 is a flowchart for explaining a conventional reading operation.

FIG. 19 is a flowchart for explaining a conventional reading operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Code reading device, 22 ... Code reading device main body, 23 ... Interface cable, 24 ... Reading port, 25 ... Trigger switch, 26 ... LED, 27 ... LED, 28 ... 2D code, 29 ... Label.

Claims (8)

[Claims] 1. A code reading apparatus comprising: an imaging unit configured to irradiate a symbol on a print medium with light and output an amount of electricity corresponding to an amount of light reflected from the symbol, and A multi-valued image data conversion means for converting the image data output from the imaging means into multi-valued image data, and detecting a transition degree of the multi-valued image data converted by the multi-valued image data conversion in a specific scan line When the degree of transition of the multi-valued image data detected by the transition degree detecting means on a specific scan line is equal to or greater than a specified value, the code reading device is moved to a focus position. And the degree of transition of the multi-valued image data detected by the transition degree detecting means on a specific scan line is a specified value. A code reading device comprising: a focus position determining unit that determines that the code reading device is not at a focus position when it is determined that the value is smaller than the focus position. 2. A code reading apparatus comprising: an imaging unit configured to irradiate a symbol on a print medium with light and output an amount of electricity corresponding to an amount of light reflected from the symbol; A multi-valued image data converting means for converting the image data output from the imaging means into multi-valued image data; and detecting a transition amount of the multi-valued image data converted by the multi-valued image data converting means on a specific scan line. A transition amount detecting means for detecting whether the transition amount of the multi-valued image data detected by the transition amount detecting means on a specific scan line is equal to or greater than a set value, When the transition amount of the multi-valued image data detected by the transition amount detection means in a specific scan line is smaller than a set value. In this case, the code reading device includes a focus position determining unit that determines that the code reading device is not at the focus position. 3. A code reading apparatus comprising: an image pickup unit configured to irradiate a symbol on a print medium with light and output an amount of electricity corresponding to an amount of light received from the symbol, and A transition degree detecting means for detecting a transition degree of the analog image signal output from the imaging means, and when the transition degree of the analog image signal detected by the transition degree detecting means is detected to be a specified value or more. Determines that the code reading device is at the focus position, and when it is determined that the transition degree of the analog image signal detected by the transition degree detecting means is smaller than a specified value, the code reading device is in focus. A code reading device comprising: a focus position determining unit that determines that the position is not at the position. 4. A code reading apparatus comprising: an imaging unit configured to irradiate a symbol on a print medium with light and to output an amount of electricity corresponding to an amount of light reflected from the symbol; A transition amount detection unit that detects a transition amount of the analog image signal output from the imaging unit; and a detection unit that detects when a transition amount of the analog image signal detected by the transition amount detection unit is equal to or more than a set value. Determines that the code reading device is at the focus position, and when it is determined that the amount of transition of the analog image signal detected by the transition amount detecting means is smaller than a set value, the code reading device focuses. A code reading device comprising: a focus position determining unit that determines that the position is not at the position. 5. When the code reading device is determined to be in the focus position by the focus position determining means according to any one of claims 1 to 4, the reading operation is performed by the code reading device. A code reading device, comprising: means for starting. 6. A code reading device, comprising: display means provided in the code reading device, wherein the focus position determination device according to any one of claims 1 to 4 determines that the code reading device is at the focus position. And a means for turning on the display means in the case. 7. The code reading device is determined to be in the focus position by the sounding means provided in the code reading device and the focus position determining device according to any one of claims 1 to 4. And a means for driving the sounding means. 8. When the code reading device is determined to be in the focus position by the vibration device provided in the code reading device, and the focus position determination means according to any one of claims 1 to 4. A means for driving the vibration device.