JP2003317031A - Optical information reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information reader which prevents unnecessary exposure processing and fetch processing from being carried out with constitution having a variable-processing-speed microprocessor which performs the exposure processing and the fetch processing for a next read in parallel while decoding read optical information. <P>SOLUTION: The microprocessor of a bar code handy terminal, when decoding a read bar code, performs the exposure processing and the fetch processing for the next read in parallel. Here, the microprocessor predicts a decoding time and performs the exposure processing and the fetch processing after the adjustment time obtained by subtracting an exposure time and a fetch time from the decoding time lapses. Consequently, the exposure processing and the fetch processing are carried out only once in the decoding time, so neither unnecessary exposure processing nor input processing is carried out. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information reader equipped with a microprocessor whose processing speed can be changed.

[0002]

In recent years, products equipped with microprocessors whose operating clocks can be changed have been supplied as bar code handy terminals. By changing the operating clocks, it is possible to meet the performance requirements of users. it can. For example, when higher speed processing is required, the operation clock is set to high speed, and when longer operation is required, the operation clock is set to low speed. The decoding time also varies according to the operating clock of the microprocessor. The faster the operating clock, the shorter the decoding time, and the slower the decoding time. The shortest decoding time can be predicted by the set operation clock and the code type.

FIG. 8 shows a conventional reading operation. In FIG. 8, for example, when the microprocessor decodes the bar code imaged by the line sensor, the microprocessor alternately executes an exposure process for exposing the line sensor and a capture process for capturing an output from the line sensor, The decoding process for decoding the captured data is performed in parallel. In this case, the exposure time and the acquisition time are determined by the specifications of the line sensor, while the decoding time varies depending on the operating speed of the microprocessor as described above.
As shown in, there are cases where a plurality of exposure processes and acquisition processes are executed in parallel within the decoding time. For this reason, the processes other than the final exposure process and capture process within the decoding time (exposure process and capture process immediately before decoding) are wasteful, and the current consumption increases accordingly.

The present invention has been made in view of the above circumstances, and an object of the present invention is to perform a parallel processing of an exposure process and a fetch process for the next reading while decoding the read optical information and a variable processing speed micro. An object of the present invention is to provide an optical information reading device that can prevent useless exposure processing and acquisition processing from being performed in a configuration including a processor.

[0005]

According to the invention of claim 1, when reading the optical information, the microprocessor executes an exposure process for exposing the optical information reading sensor by controlling the driving means. Then, the binarizing means binarizes the output from the optical information reading sensor to capture the binarized data, and decodes the binarized data.
At this time, the microprocessor executes the exposure process and the capture process in parallel while decoding the optical information. In this case, the exposure time and the capture time are constant, but the decoding time varies depending on the operating speed of the microprocessor. For this reason, there are cases where a plurality of exposure processings and acquisition processings are executed during the decoding time, and there is a risk that other than the final exposure processings and acquisition processings during the decoding time will be wasted. Here, since the microprocessor executes the exposure process and the acquisition process only once during the decoding time, the exposure process and the acquisition process are not wastefully executed, and the current consumption can be reduced. .

According to the second aspect of the invention, the microprocessor predicts the time required for decoding from its own operating speed, and subtracts the exposure time required for exposure processing and the acquisition time required for acquisition processing from this predicted decoding time. Find the adjustment time. In this case, the decoding time is the time obtained by adding the exposure time, the acquisition time, and the adjustment time. Therefore, when the adjustment time elapses from the start of decoding, the exposure processing and the acquisition processing are executed in sequence, so that the exposure during the decoding time Processing and acquisition processing can be executed only once.

According to the third aspect of the present invention, when the microprocessor starts the decoding, it executes the exposure processing and then extends the acquisition processing by the adjustment time. Therefore, during the decoding time, the exposure processing and The capture process can be executed only once.

According to the fourth aspect of the present invention, the time required for decoding is stored as the predicted decoding time. Therefore, even if the predicted decoding time is different from the actual decoding time, it is In addition, the exposure process and the capture process can be executed only once.

According to the fifth aspect of the invention, when the number of decoded data is smaller than the original number of data, the microprocessor determines that the user is not reading and lengthens the predicted decoding time. The reading interval becomes long, and the current consumption can be reduced.

According to the sixth aspect of the invention, the microprocessor drives the illuminating means during the exposure processing, so that the current consumption can be greatly suppressed even though the illuminating means is used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is applied to a bar code handy terminal (corresponding to an optical information reading sensor) will be described below with reference to FIGS. Explain. The barcode handy terminal 1 is mainly composed of a microprocessor 2. The illumination LED 3 is a red light emitting diode and uniformly illuminates the barcode label 4 to be read in response to a command from the microprocessor 2. Barcode label 4
The reflected light from the laser beam is converged by the lens 5 and converged by the line sensor 6
Imaged above. The line sensor (corresponding to an optical information reading sensor) 6 is a one-dimensional black-and-white image sensor in which a large number of photodiodes having spectral sensitivity are arranged in a straight line in the vicinity of the emission spectrum of the illumination LED 3, and is a driving circuit (corresponding to a driving unit). ) 7 and the shift pulse and the shift clock. The shift pulse is the line sensor 6
This is a signal for transferring the internal accumulated charge to the shift register, and the interval of the shift pulse becomes the exposure time of the line sensor scanning. The shift clock is a signal for outputting the electric charge from the shift register as a sensor output. That is, in order to read the bar code by the line sensor 6, two driving cycles of the exposure time and the capture time are required. The output signal from the line sensor 6 is binarized by a binarization circuit (corresponding to a binarization means) 8 and is read by the microprocessor 2 to be decoded into bar code information.

The key 9 is used to input the activation timing for starting the reading of the bar code, for example, the date and time.
The buzzer 10 is used to notify the completion of reading the bar code or to warn the battery voltage drop. The LCD 11 displays guidance to the user, bar code reading data, and the like.
The communication port 12 is used to transfer accumulated data such as barcode data to a host computer.
The memory 13 stores a program for operating the barcode handy terminal 1, decoded barcode data, and the like. The power supply circuit 14 supplies the voltage from the battery 15 in a state of being boosted for each circuit block.

Next, the operation of the above configuration will be described. When the user operates the trigger key of the keys 9, the microprocessor 2 of the barcode handy terminal 1 executes the reading of barcode information. FIG. 2 shows a reading routine by the microprocessor 2 of the barcode handy terminal 1. In FIG. 2, the microprocessor 2 first performs initial setting (S10).
1). In this initial setting, initial values of a processing flag and an adjustment time described later are set. In this case, "exposure" is set as the processing flag, and a default value is set as the adjustment time. Next, the line sensor 6, the drive circuit 7, the binarization circuit 8 and the like are powered on (S102).

Next, in order to discharge the unnecessary charges accumulated in the line sensor 6, the drive circuit 7 generates a shift pulse and a shift clock to the line sensor 6 to perform initial sweeping and initial sweeping. A timer interrupt for the required specified time is set (S103). In this case, the shift pulse given from the drive circuit 7 to the line sensor 6 is one pulse, the shift clock is a repetitive clock of multivibrator oscillation, and the charge accumulated in the photosensitive portion of the line sensor 6 corresponds to the shift pulse. The charges are transferred to the shift register, and the charges transferred to the shift register are output to the outside according to the shift clock to perform initial sweeping (initial sweeping shown in FIG. 7).

Next, the microprocessor 2 waits for an interrupt (S104), and waits in this step S104 until the timer interrupt in step S103 or the key interrupt for the key operation by the user occurs. Then, when a timer interrupt occurs at the specified time for initial sweep set in step S103, timer interrupt processing is performed.

FIG. 3 shows timer interrupt processing by the microprocessor 2. This timer interrupt processing is
This is for determining the processing to be executed when a timer interrupt occurs. In FIG. 3, the microprocessor 2
Branches to the process to be performed according to the current process flag (S201). First, step S of the reading routine
Since "exposure" is set in 101, the exposure process is executed (S202).

FIG. 4 shows the exposure process by the microprocessor 2. This exposure processing is for sweeping out unnecessary exposure at the previous time and for accumulating electric charges in the line sensor 6 for a specified exposure time in order to read the bar code. In FIG. 4, the microprocessor 2 turns on the illumination LED 3 (S301), and then causes the drive circuit 7 to generate a shift pulse while temporarily stopping the shift clock (S302). As a result, the charges accumulated in the photosensitive portion of the line sensor 6 are transferred to the shift register, and the exposure process is started.

Next, a timer interrupt for the exposure time Xms is set (S303), a shift clock is generated from the drive circuit 7 (S304), and the next process is "acquisition".
Is set as the processing flag (S305). Thereby, the unnecessary exposure transferred to the shift register can be swept out.

When the exposure process ends and the timer interrupt ends, the microprocessor 2 branches from the standby state to the end judgment of the read process itself in the read routine shown in FIG. 2 (S105). The condition to end is when the decoding is completed, or when the reading is interrupted by the user releasing the trigger switch, and when not ending (S10
5: NO), it is determined whether or not there is captured data (S10).
6). At the time of sweeping out the unnecessary exposure described above, since there is no captured data (S106: NO), a standby state waiting for an interrupt is set (S104).

Then, when the timer interrupt Xms time set in the above-mentioned exposure process has elapsed, a timer interrupt is generated again in the interrupt routine, and the process proceeds to the timer interrupt process shown in FIG. At this time, since the processing flag is "acquisition", the acquisition processing is performed (S203).

FIG. 5 shows the fetch processing by the microprocessor 2. This capture process is for capturing the charges accumulated in the previous exposure process. In FIG. 5, the microprocessor 2 turns off the illumination LED 3 (S401) and then generates a shift pulse with the shift clock temporarily stopped (S402). As a result, the charges accumulated in the photosensitive portion of the line sensor 6 are transferred to the shift register, and the fetch process is started.

Next, after setting a timer interrupt for the acquisition time Yms (S403), a shift clock is generated (S403).
404), the next process "adjustment" is set in the process flag (S405), and then data is taken in (S40).
6). Data acquisition is performed by a method that does not place a load on the microprocessor 2 by, for example, a DMA function or a processing by a gate array.

When the capture process is completed and the timer interrupt is completed, the microprocessor 2 branches from the standby state to the end judgment of the read process itself in the read routine shown in FIG. 2 (S105). If it is not completed (S105: NO), there is capture data when the above-mentioned exposure processing is completed (S106: YE).
S), data decoding is executed (S107).

At this time, when the timer interrupt Yms has elapsed and a timer interrupt occurs again, the adjustment process is executed because the process flag is "adjustment" in the timer interrupt shown in FIG. 3 (S204). That is, the adjustment process is executed at the same time when the decoding is started.

FIG. 6 shows the adjustment processing by the microprocessor 2. This adjustment process provides an adjustment time during which neither the exposure process nor the capture process is executed from the start of decoding, and the decode time is predicted as described below.
It is the time obtained by subtracting the exposure time and the capture time from the decoding time. In FIG. 6, the microprocessor 2
Turns off the illumination LED 3 (S501), and then generates a shift pulse with the shift clock temporarily stopped from the drive circuit 7 (S502). As a result, the unnecessary exposure of the line sensor 6 is transferred to the shift register.

Next, a timer interrupt for the adjustment time Zms is set (S503), a shift clock is generated from the drive circuit 7 (S504), and "exposure" which is the next process is set in the process flag (S505). ). As a result, unnecessary exposure of the shift register of the line sensor 6 is swept out (adjustment time 1 shown in FIG. 7).

When the timer interruption Zms time has elapsed after the above adjustment processing is completed, the timer interruption is generated again. At this time, in the timer interrupt shown in FIG. 3, since the processing flag is “exposure”, the exposure processing is selected and the above-described exposure processing is executed (exposure time 2 shown in FIG. 7).

When the exposure process is completed, the timer interrupt X
When the ms time has elapsed, the timer interrupt is generated again.
At this time, in the timer interrupt shown in FIG. 3, since the processing flag is “acquisition”, the acquisition processing is selected and the above-described acquisition processing is executed (acquisition time 2 shown in FIG. 7), and the timer interrupt Yms is set. To do.

Here, since the adjustment time is the time obtained by subtracting the exposure time and the acquisition time from the predicted decoding time as described later, the timer interrupt Yms time elapses at the same time when the decoding is completed, The microprocessor 2 comes to execute the adjustment processing at the same time when the next decoding is started. When the decoding process is completed,
If the decoding is completed, the process ends. However, if the decoding does not end, the decoding is performed by the next fetched data.

By the way, the bar code handy terminal 1 of this embodiment is equipped with a microprocessor 2 whose operation clock can be changed. When high speed processing is required, the operation clock is set to a high speed for a longer time. When requesting an operation, the operation clock is set to a low speed. In this case, the decoding time also varies according to the speed of the operating clock of the microprocessor 2, and the faster the operating clock, the shorter the decoding time, and the slower the decoding time.

However, the adjustment time Zms described above is set in order to absorb this variation in the decoding time. When the adjustment time Z> 0, the decoding time = exposure time X + acquisition time Y + adjustment time Z. , Adjustment time Z = 0
Only in the case of, there is a relation of decoding time = exposure time X + acquisition time Y.

FIG. 7 shows the drive timing of the line sensor 6. FIG. 7 shows a case where decoding time = exposure time + capture time + adjustment time (Z> 0). The conventional method shown in FIG. 8 does not have the above-described adjustment time, so unnecessary exposure time / acquisition time is generated, whereas in the present embodiment, unnecessary exposure time / acquisition time is generated. It turns out that you can prevent it.

According to such an embodiment, the microprocessor 2 which processes the exposure process and the capture process in parallel while decoding the read bar code executes the exposure process and the capture process only once within the decoding time. As a result, the microprocessor does not need to perform unnecessary exposure processing and acquisition processing, and may perform the exposure processing and acquisition processing multiple times within the decoding time, unlike the conventional example. 2 can be reduced.

Moreover, although the microprocessor 2 can change the operation speed, it predicts the decoding time from its own operation speed, obtains the adjustment time obtained by subtracting the exposure processing and the acquisition time from the predicted decoding time, and starts decoding. In this case, the exposure processing and the acquisition processing are executed in sequence after the adjustment time has elapsed, so that the exposure processing and the acquisition processing can be executed only once within the decoding time.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
An embodiment will be described. The second embodiment is characterized in that by adjusting the capture time, unnecessary exposure processing and capture processing are not executed within the decoding time. That is, in the first embodiment, the adjustment time is provided within the decoding time, but by setting the time including the adjustment time as the acquisition time, the same effect as that of the first embodiment can be obtained. I will get it. In this case, when the adjustment time Z> 0, the decoding time = exposure time X + acquisition time (Y + Z), and only when the adjustment time Z = 0,
Decoding time ≦ exposure time X + acquisition time Y. According to such an embodiment, it is possible to carry out only by adjusting the uptake time without providing the adjustment time as in the first embodiment.

The present invention is not limited to the above embodiments, but can be modified or expanded as follows. Instead of using the value preset in the memory as the predicted decoding time, the actual decoding time may be stored and the decoding time may be used as the predicted decoding time. That is, the decoding time can be predicted as the shortest time depending on the cycle of the operating clock of the microprocessor 2 and the type of the decoding code to be read.
Since the decoding time is affected by the code length (number of digits) and the state of the label, the accuracy can be improved by using the previous actual decoding time.

When it is judged that the barcode cannot be constructed by the number of bars fetched by the microprocessor 2, that is, when the user does not try to read the barcode label, the adjustment time and thus the predicted decoding time are set. The current consumption may be reduced by increasing the length of the reading operation.

Within the decoding time, the adjustment process may be executed after the exposure process and the acquisition process, or the adjustment process may be executed after the exposure process and then the acquisition process may be executed. . When the line sensor has an electric shutter function, the illumination LED may be kept in a lighting state. A two-dimensional sensor may be used instead of the line sensor.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing an overall configuration according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a read routine by a microprocessor.

FIG. 3 is a flowchart showing timer interrupt processing by a microprocessor.

FIG. 4 is a flowchart showing an exposure process by a microprocessor.

FIG. 5 is a flowchart showing a loading process by a microprocessor.

FIG. 6 is a flowchart showing adjustment processing by a microprocessor.

FIG. 7 is a diagram showing a shift pulse and a lighting timing of an illumination LED.

FIG. 8 is a view corresponding to FIG. 7 showing a conventional example.

[Explanation of symbols]

1 is a barcode handy terminal (optical information reading device), 2 is a microprocessor, 3 is an illumination LED (illuminating means), 4 is a barcode label, 6 is a line sensor (optical information reading sensor), and 7 is a drive circuit. (Driving means), 8
Is a binarization circuit (binarization means).

Claims (8)

[Claims] 1. An optical information reading sensor for picking up optical information, driving means for driving the optical information reading sensor, and binarizing means for binarizing an output from the optical information reading sensor. And capturing the output from the optical information reading sensor by binarizing the output from the optical information reading sensor after performing an exposure process for exposing the optical information reading sensor by controlling the driving unit. In an optical information reading device including a microprocessor capable of performing a process and performing parallel processing of the exposure process and the capture process while decoding the binarized data captured by the capture process, The optical information reading device, wherein the processor executes the exposure processing and the acquisition processing only once during the decoding time. 2. The microprocessor predicts a time required for decoding from its own operating speed, and obtains an adjustment time obtained by subtracting the exposure time required for the exposure processing and the acquisition time required for the acquisition processing from the predicted decoding time. The optical information reading apparatus according to claim 1, wherein the exposure process and the capture process are sequentially performed when the adjustment time has elapsed from the start of the decoding. 3. The microprocessor executes the exposure processing instead of sequentially executing the exposure processing and the acquisition processing when the adjustment time has elapsed from the start of the decoding when the decoding is started. The optical information reading apparatus according to claim 1, wherein the fetching process is executed after being extended by the adjustment time. 4. The optical information reader according to claim 1, wherein the microprocessor stores a time required for decoding and uses it as an estimated decoding time. 5. The microprocessor increases the predicted decoding time when the number of decoded data is smaller than the original number of data.
5. The optical information reader according to any one of 4 to 4. 6. The optical information reading device according to claim 1, further comprising an illuminating unit, wherein the microprocessor drives the illuminating unit during the exposure process. 7. The optical information reading device according to claim 1, wherein the optical information reading sensor is a line sensor. 8. The optical information reading device according to claim 1, wherein the optical information reading sensor is a two-dimensional sensor.