JP2001307011A - Optical information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information reader capable of speedily reading set voltage gain, offset value and shutter speed by one time downloading even though they are lost when power source is turned off after completion of reading and they are required to be reset in the case of re-reading. SOLUTION: In the optical information reader, values expressing a reading feasibility such as the gain, the offset value, the shutter speed are stored in an EEPROM 8 being a nonvolatile memory after the reading, and when the previous reading is success the values stored is set in the EEPROM 8 in the case of the reading.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information reading apparatus for reading a sign such as a bar code or a two-dimensional code.

[0002]

2. Description of the Related Art A bar code using a one-dimensional (linear) image sensor as an image sensor among optical information reading apparatuses will be described below. The present invention is not limited to a barcode reader, and optically reads information such as a two-dimensional code reader, an OCR reader or a handheld terminal integrated with a barcode reader, or a two-dimensional code reader integrated handheld terminal. It goes without saying that the present invention can be applied to a portable information terminal and the like that can be used.

FIG. 10 shows a block diagram of a conventional bar code reader. Reference numeral 1 denotes an image sensor which converts light reflected from a sign and its surroundings into an electric signal. Reference numeral 2 denotes an image sensor drive circuit which has an electronic shutter function capable of generating timing for driving the image sensor 1 and electrically controlling a shutter speed. The image sensor drive circuit 2 may be built in the image sensor 1 or may be built in the CPU 6 described later. A gain control circuit 3 amplifies a signal output from the image sensor 1 with a set gain. Reference numeral 4 denotes an offset control circuit for vertically offsetting the voltage level of the signal amplified by the gain control circuit 3. The order of the gain control circuit 3 and the offset control circuit 4 may be interchanged. Reference numeral 5 denotes a binarizing circuit which converts an analog signal from the offset control circuit 4 into a digital signal. 6 is CP
U is constituted by a microprocessor, and mainly performs a barcode decoding process. It is not shown that the program memory in which the execution program of the CPU 6 is stored and the work memory required for execution are often built in the CPU 6. The CPU 6 controls the gain of the gain control circuit 3,
The shutter speed is controlled by controlling the offset value of the offset control circuit 4 and changing the timing output from the image sensor drive circuit 2. Also C
The data decoded by the PU 6 is transmitted to the communication I / F 7
It is transmitted to a host such as a POS or a PC through a (communication interface).

[0004] The decoding process is also called a decoding process or a recognizing process, and is strictly a process of recognizing (decoding) a sign such as a bar code from a digital signal.
Generally, it is simply called a reading process. In the text, the decoding process means a decoding (recognition) process by the CPU, and the reading process means various settings such as initial settings, and the entire process necessary for reading including communication and decoding processes.

Next, the flow of the reading process in the conventional example is shown in FIG.
Shown in Step 1 is an initial setting process of a gain, an offset value, and a shutter speed. The CPU 6 uses the gain control circuit 3, the offset control circuit 4, and the image sensor driving circuit to respectively set the preset initial values of the gain, the offset value, and the shutter speed. Set to 2.
Step 2 is a binarization circuit output fetching process.
Captures an output signal from the image sensor 1 via a gain control circuit 3, an offset control circuit 4, and a binarization circuit 5. Step 3 is a barcode decoding process.
U6 decodes the fetched digital signal based on a barcode decoding algorithm. If decoding is successful in the decoding process (step 4), the decoding result is transmitted to an external PC or PO via the communication I / F7.
After transmission to the host such as S (step 6), the next binarization circuit output fetch is performed.

On the other hand, if the decoding has failed, at least one of the gain, the offset value and the shutter speed is changed (step 5), and the changed value is used as the gain control circuit 3, offset control circuit 4, image sensor drive circuit 2. (Step 11), the next binarization circuit output is fetched.

FIG. 12 shows a table of gain, offset value, and shutter speed stored in advance in the program memory. In step 1 of FIG. 11, for example, the gain, the offset value, and the shutter speed as the initial values are respectively set to the addresses (A000, B000, C00
0) (gain 0, offset value 0,
Shutter speed 0) is set. If the decoding is not successful, as shown in step 5 of FIG.
At least one of the offset value and the shutter speed is changed, and the next binarization circuit output is fetched.

When the power is turned off, when a reading switch (not shown) is provided and the switch is turned off, or when a reading time set in advance by a timer or the like has passed, reading is forcibly performed. End.

[0009]

In recent years, from the viewpoint of energy saving, it has been demanded to reduce current consumption as much as possible. In a bar code reader or a two-dimensional code reader, a power supply of a reading device is supplied only when reading. ing.

For use in an environment away from a host to be connected, such as in a factory or in a car, a portable optical reader generally called a handheld terminal is often used. In the handheld terminal, it is particularly necessary to control the power supply as much as possible in order to extend the use time even if it is driven by a battery, and to reduce current consumption. For this reason, every time reading is performed, the power of the portion related to reading is turned on, that is, the power of the portion related to reading is turned off except during reading.

However, in the processing shown in the flowchart of FIG.
Once the power of the reading apparatus is turned off, when the power is turned on again, it is necessary to start over from the initial setting of the gain, offset value, and shutter speed in step 1. If decoding fails with the initial values, the decoding is set to succeed. Until the value is obtained, it is necessary to change the gain, offset value, and shutter speed at least once in step 5, and there is a problem that it takes time to read successfully.
In particular, when reading a bar code having a narrow range of a decodable gain, an offset value, and a shutter speed range, for example, a bar code and its surroundings having a low contrast, a decodable gain, an offset value,
Since there are few combinations of shutter speed settings, the gain, offset value,
Since it is necessary to change the shutter speed, there is a problem that it takes a very long time until reading is successful.

Further, in the case of an optical reader of the type which reads by contacting a label containing a sign such as a bar code, the reading opening is shielded from external light, so that it may be affected by changes in the surrounding reading environment. In many cases, if the optimum gain, offset value, and shutter speed are set at the time of manufacture, there is often no need to change them thereafter. However, in recent years, mainly two-dimensional code readers, optical reading devices of a type that reads away from a label including a sign have increased. In the case of this type, since the label is directly affected by the ambient light, it is necessary to design a wide setting range and detailed steps of the setting value. There was a problem that it took a long time to succeed.

An object of the present invention is to solve such a problem and to provide an optical information reading apparatus capable of high-speed reading.

[0014]

In order to achieve the above object, a first optical information reading apparatus according to the present invention comprises: an image sensor which takes in reflected light from a sign and converts it into an electric signal;
Gain control means for setting a gain for amplifying an electric signal from the image sensor; an AD converter for converting the electric signal amplified by the gain control means into a digital signal; or an electric signal amplified by the gain control means Binarizing means, a decoding means for decoding an electric signal from the image sensor and a digitized signal for restoring the information of the sign, and a gain of the gain control means. And a gain storage means for storing the data in a non-volatile memory which can be backed up.

[0015] The second optical information reading device includes an image sensor that takes in the reflected light from the sign and converts it into an electric signal;
An offset control unit that can set an offset value of an electric signal from the image sensor; an AD converter that converts an electric signal offset by the offset control unit into a digital signal; or an electric signal offset by the offset control unit. A binarizing means for binarizing,
Decoding means for decoding a digitized signal, which is an electric signal from the image sensor for restoring the information of the sign, and storing the offset value of the offset control means in a non-volatile memory which can be electrically backed up And an offset value storing means for performing the operation.

[0016] A third optical information reading device is an image sensor that takes in the reflected light from the sign and converts it into an electric signal.
Electronic shutter control means capable of setting a shutter speed of the image sensor; an AD converter for converting an electric signal from the image sensor into a digital signal; or a binarizing means for binarizing an electric signal from the image sensor. Decoding means for decoding a digitized signal which is an electric signal from the image sensor for restoring the information of the sign, and a nonvolatile memory capable of electrically backing up a shutter speed of the electronic shutter control means And a shutter speed storing means for storing the shutter speed.

The fourth optical information reading device decodes
It has a reading success / failure storage means for storing a value indicating success or failure of decoding in a non-volatile memory which can be electrically backed up.

The fifth optical information reading apparatus decodes
It has gain storage means for storing the gain at the time of decoding in a non-volatile memory that can be electrically backed up.

The sixth optical information reading device decodes
It has an offset value storage means for storing the offset value at the time of decoding in a non-volatile memory that can be electrically backed up.

The seventh optical information reading apparatus decodes
A shutter speed storing means for storing a shutter speed at the time of decoding in a non-volatile memory which can be electrically backed up.

In the eighth optical information reading apparatus, when the previous decoding is successful, the gain at the previous decoding and / or
Alternatively, it has setting means for setting an offset value at the time of the previous decoding and / or a shutter speed at the time of the previous decoding.

After decoding, the ninth optical information reading device sets a value indicating success or failure of decoding, and / or a gain at the time of decoding, and / or an offset value at the time of decoding, and / or a shutter speed at the time of decoding. It has transmission means for transmitting to a host or the like.

The tenth optical information reading apparatus may further comprise a value indicating the success or failure of the previous decoding transmitted to the host or the like by the transmitting means, a gain at the previous decoding, and / or an offset value at the previous decoding. And / or a receiving means for receiving the shutter speed at the previous decoding from a host or the like, a gain at the time of decoding, and / or an offset value at the previous decoding, and / or a shutter speed at the previous decoding. It has setting means.

[0024] The eleventh optical information reading device may be configured such that when the value indicating success or failure of the previous decoding received by the receiving means indicates success, the gain at the time of the previous decoding and / or the last decoding Hour offset value,
And / or setting means for setting a shutter speed at the time of previous decoding.

[0025]

According to the above configuration, the first optical information reading apparatus can control the gain of the first optical information reading apparatus even if the power of the reading apparatus is turned off by the gain storage means composed of an electrically backable nonvolatile memory. The gain of the circuit can be stored.

The second optical information reading device stores the offset value of the offset control circuit even if the power of the reading device is turned off, by the offset value storage means comprising a nonvolatile memory which can be electrically backed up. Can be kept.

The third optical information reading apparatus stores the shutter speed of the electronic shutter control means even if the power of the reading apparatus is turned off, by the shutter speed storing means comprising a nonvolatile memory which can be electrically backed up. You can keep.

The fourth optical information reading apparatus has a reading success / failure result storage means comprising a non-volatile memory that can be electrically backed up, and a value indicating success or failure of decoding even if the power of the reading apparatus is turned off. Can be stored.

When the previous decoding is successful, the eighth optical information reading apparatus can decode after setting at least one of the gain, the offset value, and the shutter speed at the time of the previous decoding.

After decoding, the ninth optical information reading device can transmit to the host or the like at least one of a value indicating success or failure of decoding, a gain, an offset value, and a shutter speed.

[0031] The tenth optical information reader reads the gain, offset value,
At least one of the shutter speeds can be received from the host and their values can be set.

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

(Embodiment 1) FIG. 1 is a block diagram showing an optical information reading apparatus according to Embodiment 1 of the present invention. Here, the same portions as those in FIG. 10 showing a block diagram of a conventional example are denoted by the same reference numerals, and description thereof is omitted.

8 uses an electrically erasable EEPROM as a nonvolatile memory in the embodiment of the present invention. Note that the nonvolatile memory is not limited to the EEPROM,
It includes a ferroelectric memory (FeRAM), an SRAM and a DRAM backed up by a battery. The nonvolatile memory 8 can hold data stored in the memory even when the power of the reading device is turned off.

Reference numeral 9 denotes a reading switch. When the reading switch is turned on, the CPU 6 executes a reading process. The reading switch can be configured to perform reading while it is on and finish reading when it is turned off, or it can be configured to perform reading once when the switch is turned on or can be configured to perform reading a predetermined number of times. I do not care. Further, the read switch 9 is not always necessary, and a read command by communication from the host may be used.

FIG. 2 shows an example of the storage format of the EEPROM 8, which is divided into a gain storage area, an offset value storage area, a shutter speed storage area, and a read success / failure result storage area. The speed setting value and the value indicating the result of reading success or failure are stored after decoding. In the first embodiment of the present invention, at the time of successful decoding, the address of the set value of the gain, offset value, shutter speed and the result of decoding success / failure are stored in the EEPROM 8 at the time of decoding. When decoding fails, any one of the gain, offset value, and shutter speed is changed according to the output of the binarization circuit, and then the address of the gain, offset value, and shutter speed setting value and the decoding success / failure result are displayed. It is stored in the EEPROM 8.

In the example shown in FIG. 2, the gain (A000, B001, C005) of the set value of the gain, offset value, and shutter speed is stored as data at the addresses (D000, D001, D002) of the EEPROM 8. Decoding success / failure is stored in the address (D003) as a flag. The address (D003) contains data (00) when decoding is successful.
01), when decoding fails, data (0000) is written.

Next, FIG. 3 shows a processing flow of the first embodiment of the present invention. Here, the same processes as those in FIG. 11 showing the flowchart of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In step 11, the setting means sets the previously stored gain, offset value, and shutter speed in the gain control circuit 3, offset control circuit 5, and image sensor drive circuit 2, respectively. Specifically, when the data shown in FIG. 2 is stored, the CPU 6 sends the address (D
000, D001, D002), and set values (gain 0, offset value 1, shutter speed 5) with the data (A000, B001, C005) stored as addresses, and proceed to step 2. If the decoding is successful, after transmitting the data to the host (step 6), the gain, the offset value, and the shutter speed are stored in the addresses (D000, D001, D002) of the EEPROM 8 (step 12), and then data indicating the successful decoding (step 12). 0001) is the address of EEPROM 8 (D003)
(Step 13), and the reading process ends.
If the decoding fails, data is not transmitted to the host, and at least one of the gain, offset value, and shutter speed is changed according to the output of the binarization circuit (step 5), and the changed setting value is stored in the EEPROM 8. (D000, D001, D002) (step 12), and thereafter, data (0000) indicating decoding failure is stored in the EEPROM 8 at the address (D003).
(Step 13), the reading process ends, and the power is turned off.

Specifically, in step 5, if the decoding has failed, if the output of the binarization circuit has a large value indicating black, or if it is determined that the period during which black is indicated is long, the binarized output is output. It is determined to be small, and the offset value and gain are increased. Conversely, if there is much white, lower the offset value and gain.

As described above, in order to reduce the current consumption,
When turning on the scanner only during scanning, the bar code printing status, surrounding environment,
In particular, when the previous decoding is successful with the same ambient brightness, the gain, offset value, and shutter speed that can be decoded are set in step 11, so that decoding can be performed with the first settings after power-on. This has the effect of reducing the reading time.

In general, the surrounding environment such as the brightness at the time of reading is almost the same in an indoor room in many cases, and even in an outdoor environment, it often changes slowly without abrupt change.

Furthermore, excluding the barcodes printed on bags and containers in advance, codes used in factories, warehouses, and the transportation industry are often printed in black and the printing state is almost the same. In many cases, decoding can be performed with the gain, offset value, and shutter speed successfully decoded.

(Embodiment 2) In the first embodiment, a device for reading a barcode is used as a sign. However, it is obvious that the sign is not limited to a barcode, and may include a two-dimensional code and OCR. FIG. 4 shows a block diagram of an optical information reading device according to the second embodiment of the present invention, which is a device for reading a two-dimensional code or OCR. Reference numeral 10 denotes an AD converter that converts an analog signal into an 8-bit digital value instead of the binarization circuit 5 of FIG. As the image sensor 1, an area image sensor such as an area CCD is used. Since the output of the area image sensor has data in the two-dimensional direction, the binarization circuit 5 used in the conventional example and the bar code reader according to the first embodiment is affected by shading or the like, so that the binarization circuit 5 accurately outputs data. Since the value cannot be converted, the signal is converted into an 8-bit digital signal using the AD converter 10, and the CPU 6 performs a binarization process. Reference numeral 11 denotes an image memory, and the area image sensor generally has a large number of pixels of about 330,000 pixels.
And an SRAM and a DRAM externally. The CPU 6 decodes the data in the image memory 11. AD
D for storing the output of the converter 10 in the image memory 11
The MA (Direct Memory Access) circuit is not shown. In addition, the image sensor 1 may be an area CCD,
A MOS type area image sensor may be used.

Next, FIG. 5 shows a flow of processing according to the second embodiment of the present invention. Here, the same processes as those in FIG. 11 showing the flowchart of the conventional example and FIG. 3 showing the flowchart of the first embodiment of the present invention are denoted by the same reference numerals, and description thereof is omitted.

Step 14 is a process for loading the output of the AD converter 10 into the image memory 11. After the capture is completed, the process proceeds to a process for decoding a two-dimensional code or OCR (step 1).
5).

When an area image sensor is used as the image sensor 1, the process of step 14 for taking in the output of the AD converter 10 takes time because the number of pixels is large. Further, in the decoding of the two-dimensional code and the OCR in step 15, in addition to the large number of data, the CPU 6 has to perform the binarization processing by software, so that one decoding processing takes time. Therefore, if the previous decoding is successful, and if the printing condition of the two-dimensional code and the OCR and the surrounding environment are the same in the next decoding, the previous gain, offset, and shutter speed condition settings can be used as they are. Therefore, decoding can be performed reliably and in a short time, and the effect of reducing the reading time is greater than that described in the first embodiment.

The storage format of the gain, the offset value, the shutter speed, and the reading success / failure result in the memory is the same as that of the first embodiment shown in FIG.

(Embodiment 3) FIG. 6 shows a flow of processing according to Embodiment 3 of the present invention. Here, the same processes as those of FIG. 11 showing the flowchart of the conventional example, FIG. 3 showing the flowchart of the first embodiment, and FIG. 5 showing the flowchart of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted. Note that the block diagram used in the embodiment is the same as that in FIG. 1 used in the first embodiment.

In step 16, reception of gain, offset, and shutter speed is monitored from the host, and if there is received data, the data is received (step 17). In step 11, the received gain, offset value, and shutter speed are set. After that, capture the output of the binarization circuit (Step 2) and decode the barcode (Step 3)
And transmits to the host a value indicating the success or failure of decoding, a gain, an offset value, and a shutter speed irrespective of the success / failure of decoding (step 1).
8).

In the first embodiment, a successful gain, offset value, and shutter speed are stored when decoding is successful. However, in the third embodiment, after decoding, regardless of whether decoding succeeds or fails, decoding succeeds. A value indicating success / failure, a gain, an offset value, and a shutter speed are transmitted to the host.

In such a configuration, a combination of a gain, an offset value, and a shutter speed when decoding is successful and a combination of a gain, an offset value, and shutter speed when decoding is failed are stored in a database in the host. Gain, even if decoding fails, gain,
By changing the offset value and the shutter speed, a combination having a high possibility of successful decoding can be easily set, and the reading time can be reduced. In general, PCs and POSs are better than optical readers.
Since the host has a large memory capacity including an optical storage device such as a hard disk and the execution speed of the CPU is high, a combination of a large amount of gain, offset value, and shutter speed is used as a database, and an optimal setting value is selected. It is easy.

(Embodiment 4) FIG. 7 is a block diagram showing an optical information reading apparatus according to Embodiment 4 of the present invention. Here, the same reference numerals are used for the same portions as those in FIG. 10 showing a block diagram of a conventional example, FIG. 1 showing a block diagram of Embodiments 1 and 3, and FIG. 4 showing a block diagram of Embodiment 2. Description is omitted.

The handy terminal shown by the right broken line is
It corresponds to the host for the reading unit indicated by the broken line on the left. A display device 22 includes a liquid crystal display, a CRT, and the like.
Displays decoding results and instructions to the operator. Reference numeral 23 denotes a key input unit for inputting an instruction such as reading a bar code and turning on / off a power supply in addition to inputting a number or the like. Reference numeral 24 denotes a power supply control unit which controls not only the handy terminal unit but also the power supply of the reading unit and the control of charging of a built-in battery (not shown). Reference numeral 21 denotes a main CPU which performs a communication function with the reading unit, controls the display device 22, performs input processing from the key input unit 23, and communicates with a host such as a PC or POS. In Embodiment 4 of the present invention, EE
The PROM 8 was arranged at the handy terminal. Conventionally, in the handy terminal unit, a nonvolatile memory such as an EEPROM or an SRAM or a DRAM backed up by a battery is used for storing a decoding result of a barcode, etc. The reason is that it is not necessary to provide the information. The CPU 6 of the reading unit and the main C of the handy terminal unit
Since the PU 21 is on the same board, the communication I / F 7
Was directly connected without using.

FIGS. 8 and 9 show the flow of processing according to the fourth embodiment of the present invention. Here, FIG. 11 showing a flowchart of a conventional example,
The same processes as those in FIG. 3 showing the flowchart of the first embodiment, FIG. 5 showing the flowchart of the second embodiment, and FIG. 6 showing the flowchart of the third embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 8 shows the processing of the handy terminal unit. When a bar code reading key is input from the key input unit 23, the value indicating the success or failure of the previous decoding stored in the EEPROM 8, the previous gain, The data including the offset value and the previous shutter speed data is transmitted to the reading unit (step 30). In the transmission data, a command (command) that causes the reading unit to perform reading
Is also included.

FIG. 9 shows the processing of the reading section. The reception of the gain, offset value and shutter speed from the handy terminal section is monitored (step 20), and if there is received data, the data is received (step 21). If the received data contains an instruction to read the received data and read the data, and if the previous decoding was successful (step 10), the received previous gain, previous offset value, previous shutter speed Is set (step 11). If the received data is analyzed in step 10 and the previous decoding has failed, at least one of the received previous gain, previous offset value, and previous shutter speed was changed (step 5) and changed. A value is set (step 11). After that, the output of the binarization circuit is taken in (step 2), the bar code is decoded (step 3), and the value indicating the success or failure of decoding, gain, offset value, The shutter speed is transmitted (step 22).

The data transmitted in step 22 is shown in FIG.
The reception is monitored in step 31 of the handy terminal unit, and when there is received data of the gain, offset value, and shutter speed, the data is received from the reading unit (step 32). The received data includes a value indicating the success or failure of decoding, a gain, an offset value, and a shutter speed, and these are stored in the EEPROM 8 in steps 33 and 34, respectively.

Steps 10 and 5 in FIG. 9 are deleted, and success / failure of decoding is determined in step 4 after step 3 as shown in FIG. 3 of the first embodiment. The setting value at the time of decoding is transmitted to the handy terminal unit (step 22). If the setting value has failed, the setting value is changed in step 5 and the changed setting value is transmitted to the handy terminal unit (step 22). It does not matter.

Steps 10 and 5 in FIG. 9 are deleted, and a value indicating the success or failure of decoding, a gain, an offset value, and a shutter speed are transmitted in step 22, and the gain is changed in the handy terminal unit instead of step 5. , The offset value, and the shutter speed may be changed.

In the case of a hand-held terminal as in the fourth embodiment, the current consumption must be reduced because the battery is generally driven by a battery. If the previous decoding was successful because the bar code printing condition and the surrounding environment, especially the surrounding brightness, were the same as when the previous reading was performed, the decodable gain, offset value, and shutter speed are set in step 11. The decoding can be performed with the first setting, which has the effect of shortening the reading time.

In the handy terminal unit, barcode data and the like which have been conventionally read are stored in a non-volatile memory. Therefore, in order to store a gain, an offset value, and a shutter speed, a new area of several bytes is secured. This has the effect that there is no need to newly add a non-volatile memory.

[0063]

As is apparent from the above description, according to the first aspect, the gain of the gain control circuit is stored by the gain storage means comprising a nonvolatile memory even if the power supply of the apparatus is turned off. be able to. This allows
Even if the power is turned off to reduce power consumption when reading is not being performed, the previous gain can be read when resuming. If the printing condition and surrounding environment are the same and decoding was successful the last time, decoding can be performed with the initial set gain, reducing power consumption and
This has the effect of reducing the reading time.

According to the present invention, the offset value of the offset control circuit can be stored by the offset value storage means composed of a nonvolatile memory even if the power of the apparatus is turned off. Thus, even if the power is turned off to reduce power consumption when reading is not being performed, the previous offset value can be read when resuming. Printing condition and surrounding environment are the same,
If decoding was successful the last time, decoding can be performed with the first set offset value, which has the effect of reducing power consumption and reading time.

According to the third aspect, the shutter speed of the electronic shutter control means can be stored by the shutter speed storage means comprising a nonvolatile memory even if the power of the apparatus is turned off. Thus, even if the power is turned off to reduce power consumption when reading is not being performed, the previous shutter speed can be read when resuming. If the printing state and the surrounding environment are the same and decoding was successful the previous time, decoding can be performed at the initial set shutter speed, which has the effect of reducing power consumption and reading time.

According to the fourth aspect, the read success / failure result storage means comprising a nonvolatile memory can store a value indicating success or failure of decoding even if the power of the apparatus is turned off. This makes it possible to read the value indicating success or failure stored when reading is resumed, even if the power is turned off to reduce power consumption when reading is not being performed. Can be different from the process when the process has failed and the process when the process has succeeded.

According to claim 8, when the previous decoding is successful, the gain, offset value,
After setting the shutter speed, to decode
If the printing state and the surrounding environment are the same as those at the time of the previous decoding, decoding can be performed with the initial settings, which has the effect of reducing power consumption and reading time.
In addition, even if the previous decoding failed, the setting value is changed according to the binarized output waveform or the output waveform of the AD converter. Since the value is close to the value, the number of times of setting before decoding can be reduced, which has the effect of shortening the reading time.

According to the ninth aspect, after decoding, at least one of a value indicating success or failure of decoding, a gain, an offset value, and a shutter speed can be transmitted to a host or the like, and these values are stored in a reading unit. There is an effect that it is not necessary to provide a memory for this. Generally P
The memory capacity of the host such as C and POS is larger than that of the reading unit.
In many cases, a so-called non-volatile memory such as an EPROM is used for the host, and it is only necessary to newly provide each area in the existing non-volatile memory.

According to the tenth aspect, the optical information reading device is
At least one of the gain, the offset value, and the shutter speed at the time of the previous decoding transmitted to the host or the like can be received from the host, and those values can be set. It is not necessary to provide a memory for storing these values in the reading unit, and the gain, the offset value, and the shutter speed of the previous decoding are set, so that the previous decoding succeeds. In this case, if the printing state and the surrounding environment are the same as those at the time of the previous decoding, decoding can be performed with the initial settings. In addition, even if the previous decoding failed, the setting value is changed according to the binarized output waveform or the output waveform of the AD converter. Since the value is close to the value, the number of times of setting before decoding can be reduced, which has the effect of shortening the reading time.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical information reading device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a storage format of an EEPROM of the optical information reading device according to the first to fourth embodiments of the present invention.

FIG. 3 is a flowchart of the optical information reading device according to the first embodiment of the present invention.

FIG. 4 is a block diagram of an optical information reading device according to a second embodiment of the present invention.

FIG. 5 is a flowchart of an optical information reading device according to a second embodiment of the present invention.

FIG. 6 is a flowchart of an optical information reading device according to a third embodiment of the present invention.

FIG. 7 is a block diagram of an optical information reading device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart of a handy terminal section of an optical information reading device according to a fourth embodiment of the present invention.

FIG. 9 is a flowchart of a reading unit of the optical information reading device according to the fourth embodiment of the present invention.

FIG. 10 is a block diagram of a conventional optical information reading device.

FIG. 11 is a flowchart of a conventional optical information reading apparatus.

FIG. 12 is an explanatory diagram of an example of a storage format of a gain, an offset value, and a shutter speed in a program memory.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image sensor 2 Image sensor drive circuit 3 Gain control circuit 4 Offset control circuit 5 Binarization circuit 6 CPU 7 Communication I / F 8 EEPROM 9 Read switch 10 AD converter 11 Image memory 21 Main CPU 22 Display device 23 Key input section 24 Power control unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keiichi Kobayashi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 5B072 AA01 AA06 CC24 DD02 EE01 FF02 JJ01 JJ11 LL19 5J100 JA01 KA01 LA10 LA11 QA09

Claims (11)

[Claims] 1. An image sensor for taking in reflected light from a sign and converting it into an electric signal, gain control means for setting a gain for amplifying an electric signal from the image sensor, and electric power amplified by the gain control means. An AD converter for converting a signal into a digital signal or a binarizing means for binarizing an electric signal amplified by the gain control means, and an electric signal from the image sensor for restoring information of the sign. An optical information reading apparatus comprising: decoding means for decoding a digitized signal; and gain storage means for storing the gain of the gain control means in a non-volatile memory that can be electrically backed up. 2. An image sensor for taking in reflected light from a sign and converting it into an electric signal, an offset control means capable of setting an offset value of the electric signal from the image sensor, and an electric signal offset by the offset control means And a binarizing unit for binarizing the electric signal offset by the AD converter or the offset control unit for converting the digital signal into a digital signal, and an electric signal from the image sensor for restoring the information of the sign. Decoding means for decoding the digitized signal;
An optical information reading apparatus having an offset value storage unit for storing the offset value of the offset control unit in a nonvolatile memory that can be electrically backed up. 3. An image sensor that takes in reflected light from a sign and converts it into an electric signal, electronic shutter control means that can set a shutter speed of the image sensor, and converts an electric signal from the image sensor into a digital signal. Binarizing means for binarizing an electric signal from the AD converter or the image sensor, and decoding for decoding an electric signal from the image sensor and a digitized signal for restoring information of the marker An optical information reading apparatus comprising: a shutter speed storage unit for storing a shutter speed of the electronic shutter control unit in a nonvolatile memory that can be electrically backed up. 4. A reading success / failure storage means for storing, after decoding, a value indicating success or failure of decoding in a non-volatile memory which can be electrically backed up.
4. The optical information reading device according to any one of 3. 5. The optical information reading apparatus according to claim 1, further comprising gain storage means for storing, after decoding, a gain at the time of decoding in a nonvolatile memory which can be electrically backed up. 6. The optical information reading apparatus according to claim 2, further comprising an offset value storing means for storing, after decoding, an offset value at the time of decoding in a nonvolatile memory which can be electrically backed up. 7. The optical information reading apparatus according to claim 3, further comprising a shutter speed storing means for storing a shutter speed at the time of decoding in a nonvolatile memory which can be electrically backed up after decoding. 8. A setting means for setting a gain at the time of previous decoding and / or an offset value at the time of previous decoding and / or a shutter speed at the time of previous decoding when the previous decoding is successful. 8. The optical information reading device according to any one of 1 to 7. 9. Transmission means for transmitting to a host or the like, after decoding, a value indicating success or failure of decoding, and / or a gain at the time of decoding, and / or an offset value at the time of decoding, and / or a shutter speed at the time of decoding. The optical information reading device according to claim 1, further comprising: 10. A value indicating success or failure of previous decoding transmitted to the host or the like by the transmission means, and / or a gain at previous decoding, and / or an offset value at previous decoding, and / or Receiving means for receiving, from a host or the like, a shutter speed at the time of previous decoding; and setting means for setting a gain at the time of previous decoding and / or an offset value at the time of previous decoding, and / or a shutter speed at the time of previous decoding. The optical information reading device according to claim 9, comprising: 11. When the value indicating success or failure of the previous decoding received by the receiving means indicates success, the gain at the previous decoding and / or the offset value at the previous decoding, and / or 11. The optical information reading device according to claim 9, further comprising a setting unit for setting a shutter speed at the time of a previous decoding.