JPH1049617A - Symbol reader - Google Patents

Abstract

(57) [Summary] To stably read a two-dimensional data symbol. A substantially rectangular reading opening is provided on a bottom surface of a head portion of a housing, and a first switch and a second switch are provided outside the reading opening.
Switch 14 is provided. When reading the symbol positioned in the reading opening 12, when both the first switch 13 and the second switch 14 are pressed, the image information of the symbol is cut out and subjected to processing such as decoding. Transmitted from the cable 16 to other hardware.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a symbol reading device for reading a data symbol such as a two-dimensional bar code reader.

[0002]

2. Description of the Related Art Conventionally, POS (Point of Sa) is known.
les) As a MMF (man-machine interface) compatible with a system or the like, product information converted into a bar code is printed on the product itself or on a package, and the product information recorded on the bar code by a reading device such as a bar code reader. Is widely used. In recent years, such systems have been increasing in the amount of information added to barcodes,
In place of the method of reading a one-dimensional barcode symbol with a line sensor, a method of reading a two-dimensional data symbol having a two-dimensionally coded pattern with a two-dimensional area sensor has begun to spread. In order to accurately read the two-dimensional data symbol with the two-dimensional area sensor, the two-dimensional data symbol must be accurately positioned in the reading opening of the barcode reader and imaged on the two-dimensional area sensor.

[0003]

However, even when the two-dimensional data symbol is positioned in the reading aperture, the reading aperture is formed on a plane (hereinafter, referred to as a "symbol surface") on which the two-dimensional data symbol is formed due to hand shake of an operator or the like. ), Or the case of the bar code reader may be tilted and the distance between the symbol surface and the reading aperture may not be uniform. The photographing optical system provided in the housing of the bar code reader, when the symbol surface comes into contact with the wall surface of the housing in which the reading opening is formed,
Since the two-dimensional data symbols are arranged so as to be imaged on the two-dimensional area sensor, the image formed on the two-dimensional area sensor may be blurred or distorted if the reading operation is performed in the above-described state. Thus, accurate reading of the two-dimensional data symbol is not performed.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to stably read a two-dimensional data symbol.

[0005] In this specification, "symbol surface" refers to a surface including a two-dimensional data symbol positioned at the opening of the symbol reading device, and "symbol reading" is positioned at the reading opening. The processing from the imaging of the surface to the extraction and decoding of the image information of the two-dimensional data symbol.

[0006]

A symbol reading apparatus according to the present invention has a symbol surface on which a coded symbol is formed facing one wall surface of a housing, and positions the symbol in a reading opening provided on the wall surface. A symbol reading device for reading a symbol optically, comprising: a symbol reading device for optically reading a symbol; and a contact sensing device provided on a wall surface for sensing a contact state between the symbol surface and the wall surface. Wherein the symbol reading means performs a reading operation when all the sensing elements are sensing contact.

Further, the symbol reading device according to the present invention has a symbol surface on which a coded symbol is formed facing a wall surface of a housing, and reads the symbol by positioning it in a reading opening provided in the wall surface. Means for imaging a symbol surface, means for extracting symbol information from imaging information by the imaging means, and contact sensing means provided on the wall surface and sensing a contact state between the symbol surface and the wall surface. The contact sensing means has a plurality of spaced sensing elements, and the imaging means or the symbol information extracting means is driven based on a combination of sensing states of each sensing element.

[0008] The imaging means is preferably activated when one of the sensing elements senses contact with the symbol surface.

[0009] The symbol extraction means is preferably activated when all of the sensing elements are sensing contact with the symbol surface.

The sensing element is provided, for example, at a point-symmetric position with respect to the center of the reading aperture.

[0011] The reading aperture is preferably square,
Two sensing elements are provided on the diagonal extension of the reading aperture.

The sensing element is, for example, an on / off switch in which the on state is maintained while being energized by the pressing force, and the off state is maintained while being not energized by the pressing force.

The sensing element is preferably provided with a non-slip member.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a symbol reading device according to an embodiment of the present invention. The housing 10 includes a head 10a and a grip 10b. The bottom surface 11 is one wall surface of the head unit 10a in which a rectangular reading opening 12 is formed. Reading aperture 1 on bottom 11
2 and the first switch 13 and the second switch 1
4 are provided. The first switch 13 and the second switch 14 are arranged symmetrically with respect to the center of the reading opening 12 and on a diagonal line connecting the corners of the reading opening 12. The first switch 13 and the second switch 14 are self-return type on / off switches, and are turned on when the tip portion and the bottom surface 11 are pressed to be uniform. In addition, for example, a rubber anti-slip member is provided at the tip.
A trigger 15 for starting a reading operation is provided on a side surface of the grip 10b. A cable 16 for transmitting a read result to an external device (not shown) such as a host computer is attached to an end of the grip 10b opposite to the head 10a.

FIG. 2 is a block diagram of the symbol reading device according to the present embodiment. A CPU (Central Processing Unit) 20 controls the entire symbol reading device. The first switch 13 includes a NOR circuit 51, an OR circuit 52, and an AND circuit 5 which are logic circuits via an inverter 13a.
3 and the second switch 14 is connected to a NOR circuit 51, an OR circuit 52, and an
It is connected to a circuit 53. The port P ₁ output signals of the CPU20 of the NOR circuit 51, the output signal of the OR circuit 52 to the port P _2, the output signal of the AND circuit 53 is the port P
Entered in ₃ . The trigger 15 is connected to the inverter 15
a and the output signal of the inverter 15a is C
Is input to the port P _SW of PU20.

The CPU 20 includes various circuits constituting the imaging circuit 30, that is, a power supply circuit 31, a CCD drive circuit 32,
The light source drive circuit 33 and the signal processing circuit 34 are connected. A power supply circuit drive signal for controlling the power supply circuit 31 is output from the port P _EN /.
Power is supplied from 1 to the CCD 35 and other circuits of the imaging circuit 30. Control signals for the CCD drive circuit 32 and the light source drive circuit 33 are transmitted through ports S ₁ and S ₁ respectively.
It is output from the S _2. The power supply circuit drive signal is an active low signal that causes the power supply circuit 31 to supply power to various circuits when it is low (L).

The light source 36 is driven in accordance with a control signal output from the light source driving circuit 33 to illuminate the symbol surface with illumination light, and the reflected light from the symbol surface forms an image on the CCD 35.
The CCD 3 according to the control signal output from the drive circuit 32
5 is driven, and the optical image of the symbol surface is photoelectrically converted.
The image information of the photoelectrically converted symbol surface, that is, all pixel data output from the CCD 35 is output to the monitor display circuit 39.
Is output to the monitor 37 via the. The monitor 37 is provided, for example, on the upper surface of the housing 10 (not shown), so that the operator can visually check the state of the reading aperture by the image projected on the monitor 37. Further, all pixel data is outputted to the monitor 37, the signal processing circuit 34 is subjected to binarization processing and the like are input to the port P _4. From the CCD driving circuit 32 is input to the port P ₅ is output synchronizing signal used for the extraction of the symbol information. In CPU 20, and stores the synchronization signal input to all the pixel data input to the port P ₄ to the port P ₅ on the basis of the (vertical, horizontal sync signal and the field index signal FI) in a memory (not shown).

Further, the CPU 20, the input synchronizing signal to the port P ₅ information from the image information of the symbol surface which has been stored in the memory of the symbols based on the (vertical, horizontal sync signal and the field index signal FI) is extracted Then, processing such as decoding is performed based on the extracted symbol information. The symbol information that has been successfully decoded is output from the port P ₆ and transmitted to the host computer via the external interface 38.

Next, using the truth table 1 of FIG. 3, the CPU according to the state of the first switch 13 and the second switch 14
The control processing of the image pickup circuit 30 in 20 will be described. In the truth table 1, as for the values of the switches and the ports P ₁ , P ₂ , and P ₃ , 0 is a low signal indicating a low voltage, and 1 is a high signal indicating a high voltage. In addition, the value of the port _PEN / indicates a value 0 means low and turns on the power supply circuit 31 to operate it, and 1 means a high value and turns off the power supply circuit 31 and disables it.

The first row of the truth table 1 shows the value of each port when both the first switch 13 and the second switch 14 are off. When the first switch 13 and the second switch 14 are not pressed, a high voltage is input to the inverters 13a and 14a, and the inverters 13a and 14a
Output a low signal from the NOR circuit 51 and the OR circuit 5
2. Input to the AND circuit 53. Therefore, the NOR circuit 5
The signal output from port ₁ and input to port P ₁ is high,
Signal input to the to the port P ₂ output from the OR circuit 52 is low, the signal input to the port P ₃ is output from the AND circuit 53 becomes low.

The second row of the truth table 1 shows the value of each port when the first switch 13 is turned on and the second switch 14 is turned off. A high signal is output from the first inverter 13a and input to each logic circuit, and a low signal is output from the second inverter 14a and input to each logic circuit. Therefore, the signal input from the NOR circuit 51 to the port P ₁ is low, the signal output from the OR circuit 52 and input to the port P ₂ is high, and the signal output from the AND circuit 53 and input to the port P ₃ is Go low.

The third row of the truth table 1 shows the value of each port when the first switch 13 is turned off and the second switch 14 is turned on. A low signal is output from the first inverter 13a and input to each logic circuit, and a high signal is output from the second inverter 14a and input to each logic circuit. Therefore, from the NOR circuit 51 to the port P
Signal inputted to the ₁ row, the signal input to the port P ₂ is output from the OR circuit 52 is high, the signal input to the port P ₃ is output from the AND circuit 53 becomes low.

The fourth row of the truth table 1 shows the value of each port when both the first switch 13 and the second switch 14 are turned on. When the first switch 13 and the second switch 14 are pressed, a low signal is output to the inverter 1.
3a and 14a, a high signal is output from the inverters 13a and 14a, and the NOR circuit 51 and the OR circuit 5
2. Input to the AND circuit 53. Therefore, the NOR circuit 5
The signal output from port ₁ and input to port P ₁ is low,
The signal input to the port P ₂ is output from the OR circuit 52 is high, the signal input to the port P ₃ is output from the AND circuit 53 becomes high.

The value of port P _EN / is determined by the value of port P ₁ . When the value of the port P ₁ is a high port P _EN /
Port P when the value is high (1), the value of the port P ₁ is low
The value of _EN / is low (0). The value of the port P ₁ is high, the first switch 13 as described above, the second switch 14 are both case off only. That is, the first
When both the switch 13 and the second switch 14 are off,
Since the power supply circuit 31 is not driven, the other circuits of the image pickup circuit 30, the CCD drive circuit 32, the light source drive circuit 33, and the signal processing circuit 34 are not driven, so that the image processing of the symbol surface is not performed. On the other hand, if at least one of the first switch 13 and the second switch 14 is pressed,
The power supply circuit 31 is driven, the imaging circuit 30 is driven accordingly, and the image processing of the symbol surface is started.

FIG. 4 is a processing flow from the symbol plane imaging processing to the symbol data transmission. At the start of the processing flow, the power of the symbol reading device main body is turned on, and the CPU 20 is in the operating state. In step 100, the port P _EN / is initialized, and the output value is set to 1. That is, in step 100, the imaging circuit 3
0 is turned off.

In step 101, the trigger switch 15
It is determined whether or not is pressed (whether or not it is turned on). If it is not pressed, the process proceeds to step 102. If it is pressed (it is turned on), the port P _EN / is set to 0 at step 103. Is set, the power supply of the imaging circuit 30 is turned on, imaging of the symbol surface is performed, and binarization processing and predetermined image processing are performed on the image information of the symbol surface read by the imaging, and the image information is stored in the memory. Proceed to step 108.

[0027] confirmed the value of the port P ₁ in step 102, 0 i.e. the first switch 13, the process proceeds to step 104 if at least one of ON of the second switch 14, if both switches also ON Returning to step 100, the power supply of the imaging circuit 30 is turned off.
In step 104, the port P _EN / is set to 0, the power of the imaging circuit 30 is turned on, the image of the symbol surface is taken, and 2 is added to the image information of the symbol surface read by the imaging.
After being subjected to a value conversion process or a predetermined image process, the image data is stored in the memory, and the process proceeds to step 105.

In step 105, it is determined whether or not the trigger 15 has been pressed as in step 101. If the trigger 15 has not been pressed, the process proceeds to step 106, and if it has been pressed, the process proceeds to step 108.

In step 106, the value of the port P ₁ is confirmed. If 0, that is, if at least one of the first switch 13 and the second switch 14 remains on, the process proceeds to step 107, where the value of the port P ₁ is determined. Is 100, that is, if both switches are off, step 100
Then, the power supply of the imaging circuit 30 is turned off. Step 10
Check the value of the ports P ₂ and port P ₃ in 7, the process proceeds to step 108 if both 1 i.e. both on state the first switch 13 and second switch 14. If the value of either port P ₂ or port P ₃ is 0,
Alternatively, if both port values are 0, step 1
Return to 05.

In step 108, a symbol extraction process, that is, a process of reading image information of the symbol surface from the memory and extracting only pixel data corresponding to the symbol from the image information is performed. Next, in step 109, decoding processing is performed based on the pixel data extracted in step 108. If the decoding process is successful, the symbol information decoded in step 110 is transmitted to an external host computer as symbol reading success. If the decoding process fails, no transmission to the host computer is performed. The result of symbol reading is notified to the operator by a buzzer or a display lamp (not shown) provided on the housing, etc., on the result of decoding.

As described above, in the present embodiment, the first
When only one of the switch and the second switch is turned on, the value of the port _PEN / is only set to 0. That is, the imaging process of the symbol plane is performed by the imaging circuit 30, and the binarized data of the symbol plane is
Only is input to the port P ₄ of 20, extraction processing of the symbol is not performed. Therefore, the image pickup circuit rises when either the first switch 13 or the second switch 14 is turned on, and the symbol surface is displayed on the monitor 37, so that the operator can visually check the state of the symbol surface and turn on both switches. Can be prevented from deviating from the inside of the reading aperture until the symbol extraction process is performed while holding the symbol.

First switch 13 and second switch 14
Are in the ON state, symbol extraction processing is performed assuming that proper reading is possible, and the extracted symbol data is decoded.

In the present embodiment, the first switch 13 and the second switch 14 are located on a diagonal line of the rectangular reading opening 12 and are turned on when the leading end becomes uniform with the bottom surface 11 by being pushed. Switch. Therefore, by holding both switches in the ON state, the reading aperture 12 is fixed in close contact with the symbol surface, so that camera shake is easily prevented, and the symbol image formed on the CCD 35 is blurred or distorted. The phenomenon can be avoided.

Further, the first switch 13 and the second switch 14 are provided on the diagonal line of the reading opening 12 by using a switch which is turned on just by being pushed even if the tip is not even with the bottom surface 11. You may. By operating the bar code reader while both switches are kept on, the bar code reader will swing in a diagonal direction even if hand shake occurs. Since the corners other than the corner where the second switch 14 is disposed abut on the symbol surface, the inclination of the bar code reader is extremely low.
The phenomenon that the symbol image formed on the image 5 is blurred or distorted is minimized.

In the present embodiment, the number of switches is two (the number of switches is two) in order to avoid that each processing such as decoding in the CPU 20 becomes complicated and the rapid data processing cannot be performed with the increase in the number of switches provided on the bottom surface 11. Only the first switch 13 and the second switch 14) realize the effect of disposing the above-mentioned switches on the diagonal line of the reading aperture with the minimum number of switches.

Since the first switch 13 and the second switch 14 are provided at point-symmetric positions with respect to the center of the reading opening 12, the head unit 10a is turned on by turning both switches on. It is prevented that only one side of the bottom surface 11 contacts the symbol surface and the other three sides are significantly separated from the symbol surface, so that the reading aperture can be easily fixed to the symbol surface.

In order to prevent the housing once fixed from sliding on the symbol surface while the first switch 13 and the second switch 14 are on, the first switch 13 and the second switch are used. A rubber member is provided at the tip of 14.

Therefore, the image information of the symbol plane output from the imaging optical system is not disturbed. Therefore, it is possible to prevent the position of the symbol on the symbol surface from being specified or to extract erroneous symbol information, and to stably extract the symbol information.

Further, the first switch 13 or the second switch
When the imaging circuit starts up in a state where one of the switches 14 is pressed, the symbol extraction process can be started almost simultaneously with the pressing of both switches, thereby shortening the processing time.

In this embodiment, the switches are provided at two places, but the present invention is not limited to this. It is sufficient that a plurality of switches are provided at point-symmetric positions with respect to the center of the reading aperture.

In this embodiment, the first switch 1
3. A rubber member is provided at the tip of the second switch 14, but is not limited to this, and any switch can be used as long as it can prevent each switch from sliding on the symbol surface.

[0042]

As described above, according to the present invention, when reading a symbol such as a two-dimensional bar code, the hand movement of the operator is prevented, so that the symbol extraction process can be performed stably.

[Brief description of the drawings]

FIG. 1 is a perspective view of a symbol reading device according to the present invention.

FIG. 2 is a block diagram of the symbol reading device of the present invention.

FIG. 3 is a truth table of arithmetic processing in a CPU incorporated in the symbol reading device.

FIG. 4 is a processing flow of symbol reading according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 housing 12 reading opening 13 first switch 14 second switch 15 trigger 20 CPU 30 imaging circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G06K 7/10 G06K 7/10 P

Claims (8)

[Claims] 1. A symbol reading device for reading a symbol by positioning a symbol surface on which a coded symbol is formed to face one wall surface of a housing and positioning the symbol in a reading opening provided on the wall surface. Symbol reading means for optically reading, provided on the wall surface,
A contact sensing unit for sensing a contact state between the symbol surface and the wall surface, wherein the contact sensing unit has a plurality of spaced sensing elements, and all of the sensing elements sense contact. The symbol reading device performs a reading operation. 2. A symbol reading device, wherein a symbol surface on which a coded symbol is formed is opposed to one wall surface of a housing, and the symbol is read in a reading opening provided in the wall surface, and wherein the symbol surface is read. Means for imaging the symbol, means for extracting the information of the symbol from the imaging information by the imaging means, and a contact sensing means provided on the wall surface and sensing a contact state between the symbol surface and the wall surface, A symbol reading device, wherein the contact sensing means has a plurality of spaced sensing elements, and wherein the imaging means or the symbol information extracting means is driven based on a combination of sensing states of the sensing elements. 3. The symbol reading device according to claim 2, wherein the imaging unit is driven when one of the sensing elements senses contact with the symbol surface. 4. The symbol reading device according to claim 2, wherein the symbol extracting means is driven when all of the sensing elements sense contact with the symbol surface. 5. The symbol reading device according to claim 1, wherein the sensing element is provided at a point-symmetric position with respect to a center of the reading aperture. 6. The symbol reading device according to claim 5, wherein the reading aperture is rectangular, and two sensing elements are provided on a diagonal line of the reading aperture. 7. An on / off switch wherein the on state is maintained while the sensing element is energized by the pressing force, and the off state is maintained while the sensing element is not energized by the pressing force. A symbol reading device according to claim 6. 8. The symbol reading device according to claim 7, wherein a non-slip member is provided on the sensing element.