JPH06301803A - Bar code reader - Google Patents

Abstract

PURPOSE:To accelerate data transfer at the time of continuous read of plural bar codes. CONSTITUTION:Bar code data is written in each unit storage area of a bar code data storage area in a RAM with a period (t1+t2) by the DMA system (steps 304, 305, and 306). Bar code data in the unit storage area is encoded to an ASCII code. The coincidence between current data encoded to the ASCII code and preceding data encoded to the ASCII code is discriminated; and when the frequency in coincidence reaches '2', pertinent data is transferred to the outside. If the number of bars is increased or reduced (steps 311 and 313) after the frequency in coincidence reaches 2 (step 312), continuation of the decoding processing for the pertinent bar code is stopped, and the decoding processing for the next bar code is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a bar code reader,
More particularly, it relates to a bar code reader having a direct memory access (DMA) function.

[0002]

2. Description of the Related Art As a bar code reading device, a handy type bar code reading device incorporating a CCD image sensor is known.

Conventionally, this type of bar code reader has been
As shown in FIG. 7, when a plurality of barcode labels A and B (shown in (a)) are read, the barcode data A ₁ , A ₂ , A ₃ ... Is fetched (shown in (b)). Decoding process C of each bar code data A ₁ , A ₂ , A ₃ ...
₁ , C ₂ , C ₃ ... (C () in the figure) are performed in a time-division manner, and the number of coincidences of the decoded data is a predetermined value (in FIG. 7, coincidence between A ₁ and A ₂ and A ₂ and A _{2). When} the total number of coincidences with ₃ is "2"), the decoded data is transferred to the host computer or the like. However, this conventional bar code reader has a problem that the reading speed is slow because the decoding processing time t ₀ is relatively long and the capture processing cycle T must be set large.

Therefore, recently, there has been a demand for the development of a bar code reading apparatus which has a DMA function and can perform a reading process and a decoding process in parallel to improve the reading speed.

As a bar code reading device which meets this demand, a bar code which is composed of a predetermined number of unit storage areas and in which bar code data is sequentially written in each of the unit storage areas at a predetermined cycle by the direct memory access method. A data storage area, a decoding means for decoding the bar code data in each unit storage area, and the number of times of matching the decoded data is obtained, and when the number of times of matching reaches a predetermined value, the decoded data is transferred. A bar code reader having a data transfer means for doing so is conceivable.

FIG. 8 to FIG. 10 show the processing of this bar code reader (hereinafter referred to as the "prior art of the present invention"). It should be noted that the description of this processing content is omitted because it largely overlaps with the processing content in the embodiment of the present invention described later (in the figure, the same reference numerals as those of the embodiment denote the same processing as that of the embodiment. ).

[0007]

[Problems to be Solved by the Invention] However, the above-mentioned book
In the precondition technique of the invention, as shown in FIG.
When reading code labels A, B and C continuously,
Match count for code label A ((a) in the figure) established
Even afterward, each unit storage area B_Four , B_Five (Illustration
In the barcode label A already written in (b))
Related barcode data A_Four , A_Five (Shown in (b))
Useless decoding process C_Four , C_Five Continue ((c) in the figure)
The barcode label B,
There is a problem in that each data transfer point of C is delayed.
In particular, as shown in FIG. 12, each barcode label A,
If the scan operation time for B and C is long,
Number of matches for barcode label A ((a) in the figure)
Even after establishment, each unit storage area B _Four , B_Five , B₆ ，
B₇ Bar code already written in ((b) in the figure)
Many bar code data A for label A_Four , A_Five ，
A₆ , A₇ Useless decoding processing for ((b) in the figure)
C_Four , C_Five , C₆ , C₇ To continue ((c) in the figure)
Therefore, when each data of barcode label B, C is transferred
The points will be further delayed.

The present invention aims to solve the problems of the above-described prerequisite technique of the present invention and to accelerate the data transfer timing when continuously reading a plurality of bar codes, in other words, to improve the reading speed. To aim.

[0009]

In order to solve the above-mentioned problems, a bar code reader according to the present invention comprises a predetermined number of unit storage areas as shown in FIG. 13 and uses a direct memory access method. A bar code data storage area in which bar code data is sequentially written in each of the unit storage areas, a decoding means for decoding the bar code data in each of the unit storage areas, and the number of coincidences of the decoded data are shown. A bar code reading device comprising: a data transfer unit that transfers the decoded data when the number of coincidences reaches a predetermined value, wherein the number of coincidences reaches the predetermined value and a bar code of a bar code. When the increase / decrease in the number of lines is detected, the decoding process for the corresponding bar code is stopped and the decoding process for the next bar code is stopped. Characterized in that a decoding control means for starting.

[0010]

When a plurality of bar code labels are continuously read, the direct memory access method can be used to perform bar code data acquisition processing and decoding processing in parallel. It is possible to speed up the data transfer period of. Further, when it is detected that the number of times of matching reaches a predetermined value and the number of bars of the barcode has increased or decreased, the decoding process for the matched bar code is stopped and the decoding process for the next bar code is stopped. Since it is configured to start, the decoding process for the next barcode is started early, and the data transfer timing for each barcode after the next barcode can be accelerated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block configuration of a bar code reader according to an embodiment.

In FIG. 1, a bar code reader 1
Includes a CPU 3 having a built-in DMA 2. Further, the bar code reading apparatus 1 has a ROM 4 in which operation programs and the like are stored in advance, and an RA capable of temporarily reading and writing data.
M5, LED 7 for irradiating the barcode label 6, CCD for outputting the reflected light of the barcode label 6 as an electric signal
The image sensor 8, the A / D converter 9 that binarizes the analog output signal of the CCD image sensor 8, and the I / F circuit 10 that outputs data to a host computer (not shown)
And so on.

2 to 4 show processing contents executed by the CPU 3. Hereinafter, the contents of each processing step will be described, and then the operation will be described.

(1) At start (FIG. 2) 1) Initial setting (step 101) When the power of the bar code reader 1 is turned on, the mode flag is set to the sensor drive mode and the capture permission flag is set. Perform predetermined initialization such as

2) DMA initial setting (step 102) A predetermined initial setting for DMA is performed by assigning a predetermined number of bar code data storage areas, for example, eight unit storage areas for DMA, to a predetermined address in the RAM 5. .

3) Scan interrupt setting (step 103) The timing of the first scan interrupt is set.

(2) Main processing (FIG. 3) 1) Pre-decoding processing (step 201) It is judged whether there is one scan of barcode data, and the barcode data written in each unit storage area is checked. A predetermined process before the decoding process such as transfer to a predetermined register in the CPU 3 is performed.

2) Decoding process (step 202) The bar code data is converted into ASCII code.

3) Decoding pass / fail judgment (step 203) It is determined whether or not the decoding process is performed correctly.

4) Match Count Judgment (Step 204) This time the ASCII coded data and the previous AS
It is determined whether or not the CII coded data matches and whether or not the number of times of matching reaches a predetermined value, for example, "2".

5) Transfer Flag Reset (Step 205) If it is determined in step 204 that the number of coincidences has not reached the predetermined value, the transfer flag is reset.

6) Transfer Data Difference Judgment (Step 206) It is judged whether the ASCII code data this time is the same as the data transferred to the host computer last time.

7) Data transfer (step 207) If the current ASCII coded data is different from the data previously transferred to the host computer, the current data is transferred to the host computer via the I / F circuit 10. .

8) Transfer flag setting (step 208) The transfer flag is set.

9) Acquisition permission (step 209) The acquisition permission flag is set.

(3) Scan interrupt (FIG. 4) 1) Mode discrimination (step 301) It is discriminated whether the sensor drive mode or the exposure adjustment mode by looking at the mode flag.

2) Change flag (step 302) When it is determined in step 301 that the sensor drive mode is set,
Change the mode flag to exposure adjustment mode.

3) Interrupt time (t ₁ ) setting (step 30)
3) Set the next interrupt time (t ₁ ).

4) Sensor drive (step 304) The CCD image sensor 8 is driven.

5) Judgment permission decision (step 305) It is judged whether the fetch is permitted or not by referring to the fetch permission flag.

6) Start of acquisition (step 306) When it is determined in step 305 that the acquisition is permitted, the DMA is activated and the bar code data is written in the unit storage area.

7) Change Flag (Step 307) If the exposure adjustment mode is determined in step 301, the mode flag is changed to the sensor drive mode.

8) Stop acquisition (step 308) Stop DMA.

9) Interrupt time (t ₂ ) setting (step 30)
9) Set the next interrupt time (t ₂ ).

10) Judgment permission determination (step 310) It is judged by referring to the fetch permission flag whether the fetch is permitted.

11) Checking the number of bars (step 311) If it is determined in step 310 that the import is permitted, the number of bars is checked, and if it is confirmed that the number of bars this time has increased or decreased from the number of bars last time, Remember this.

12) Transfer Flag Judgment (Step 312) It is judged whether or not the transfer flag is set.

13) Judgment of Number of Bars (Step 313) When it is judged in step 312 that the transfer flag is set, it is judged whether or not the number of bars has changed.

14) Buffer clear (step 314) When it is determined in step 313 that the number of bars has changed, access to the unit storage area in which the bar code data relating to the bar code before the number of bars change is written is prohibited. Then, the access is started from the unit storage area in which the bar code data regarding the changed bar code is written.

15) Judgment of use of all buffers (step 31)
5) It is determined whether or not the bar code data is written in all the unit storage areas.

16) Prohibition of acquisition (step 316) When it is judged in step 315 that all buffers are in use, the acquisition permission flag is reset.

Next, the main operation of the CPU 3 will be described in order.

1) Bar code data acquisition processing In the scan interrupt processing shown in FIG.
By the memory access method, the bar code data is written in a predetermined order in each unit storage area of the bar code data storage area in the RAM 5 at a cycle (t ₁ + t ₂ ) (steps 304, 305, 306). When the barcode data that has not been decoded yet is written in the entire barcode data storage area, the fetching process is not executed (steps 315 and 316).

2) Bar Code Data Decoding Processing In the main processing shown in FIG. 3, the unit storage areas of the bar code data storage area are accessed in a predetermined order, and the bar code data written in the unit storage area is accessed. The CPU
The data is transferred to a predetermined register in 3 and then ASCII coded (steps 201 and 202).

3) Data transfer In the main process shown in FIG. 3, it is determined whether the data encoded in the current decoding process is ASCII coded and the data encoded in the previous decoding process is the ASCII code. When a value, for example, "2" is reached, the ASCII coded data is transferred to the host computer (steps 204, 206, 20).
7).

4) Decode Control In the scan interrupt process shown in FIG. 4, it is detected that the number of bars of the bar code has increased or decreased after the number of coincidence reaches a predetermined value (step 208 of FIG. 3, step 312 of FIG. 4). (Steps 311 and 313), the decoding process for the matched bar code is stopped,
The decoding process for the next bar code is started (step 314).

As described above, in the present embodiment, when a plurality of bar code labels are continuously read, the direct memory access method is adopted so that the bar code data acquisition processing and the decoding processing are performed in parallel. Therefore, it is possible to accelerate the data transfer time after decoding.

Furthermore, according to the present embodiment, as shown in FIG. 5, when the bar code labels A, B, and C are continuously read, the number of coincidences for one bar code label A (shown in (a)) is established. After that, when the increase or decrease in the number of bars is detected, the decoding process is started for the bar code data A ₅ (shown in (b)) of the bar code label A already written in the unit storage area B ₅ (shown in (b)). Without, barcode data A ₆ for barcode label B (illustration (b))
Then, the decoding process C ₆ ((c) in the figure) is started. Therefore, compared with the above-described base technology of the present invention, it is possible to speed up the data transfer timing of each of the barcode labels B and C. In particular, as shown in FIG. 6, the effect becomes more remarkable when the scanning operation time for each bar code label A, B, C is long.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a bar code reader according to an embodiment.

FIG. 2 is a flowchart showing the operation of the CPU at the start of processing.

FIG. 3 is a flowchart showing the main processing of the CPU.

FIG. 4 is a flowchart showing scan interrupt processing of the CPU.

FIG. 5 is a timing chart for explaining main operations of the CPU.

FIG. 6 is a timing chart for explaining the main operation of the CPU.

FIG. 7 is a timing chart for explaining the operation of the conventional example.

FIG. 8 is a flowchart showing an operation at the time of starting processing of the base technology of the present invention.

FIG. 9 is a flowchart showing main processing of the base technology.

FIG. 10 is a flowchart showing a scan interrupt process of the base technology.

FIG. 11 is a timing chart for explaining the operation of the base technology.

FIG. 12 is a timing chart for explaining the operation of the base technology.

FIG. 13 is a conceptual diagram of the present invention.

[Explanation of symbols]

 1 Bar code reader 2 DMA 3 CPU 5 RAM 6 Bar code label

Claims (1)

[Claims] 1. A bar code data storage area comprising a predetermined number of unit storage areas, in which bar code data is sequentially written to each of the unit storage areas in a predetermined cycle by a direct memory access method, and each of the unit storage areas. Bar code reading including a decoding means for decoding the bar code data in the inside and a data transfer means for obtaining the number of coincidences of the decoded data and transferring the decoded data when the number of coincidences reaches a predetermined value. In the device, when the number of coincidences reaches the predetermined value, and when an increase or decrease in the number of bar codes of the bar code is detected, the decoding process for the bar code having the coincidence is stopped and the next bar code is detected. A bar code reading device comprising a decoding control means for starting a decoding process.