JPH0644222B2 - Bar code reading control method in serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a bar code reading control method by bar code end detection in a serial printer having a bar code reading function, without calculating or measuring the bar code width other than the effective bar code printing area. The output signal of the mark sensor in a serial printer equipped with a mark sensor on the print head carrier is aimed at speeding up the barcode reading by suppressing the read data to the minimum necessary without performing unnecessary reading operation. A bar code end detection function that detects the bar code end from the bar code end detection function is provided when the print head carrier is moved and the bar code on the printer paper is read by the mark sensor. Immediately when the code end is detected To stop the movement of controls to end the reading operation of the bar code.

[Industrial application field]

The present invention relates to a bar code reading control method by bar code end detection in a serial printer having a bar code reading function.

Recently, a serial printer has a bar code reading function that allows the bar code printed on the printer paper to be read, and print control information such as the paper type and print item type can be input from the printer paper. Being developed. The present invention provides a bar code reading control method for reducing the time required for bar code reading in such a serial printer without calculating or measuring the bar code width.

[Conventional technology]

FIG. 4 shows an outline of a bar code reading control method in a conventional printer.

In FIG. 4, 1 is printer paper, 2 is a bar code print area, 3 is a print head carrier, and 4 is a mark sensor mounted on the print head carrier 3.

The carrier 3 is continuously fed from a starting position at the left end of the drawing to a stopping position at the right end by a carrier motor (not shown). The reading range of the mark sensor 4 is the carrier 3
It is preset to a certain size within the moving range of.

FIG. 5 is a flow chart showing an example of bar code reading control in such a conventional printer.

In brief, the reading range and carrier stop position shown in FIG. 5 are set.

Then, the movement of the carrier is started, and it is monitored that the start position of the reading range is reached by, and when the start position is reached, the reading mode of the mark sensor is set.

When the reading mode is set, the reading state of the bar code is entered, and by the carrier interrupt processing of, each time the carrier address is updated, the read data of the mark sensor output is fetched and sequentially set in the buffer. Since the carrier interrupt is generated at a constant timing during the movement of the carrier, the bar code data sampled for each constant section is read into the buffer.

Next, when it is detected that the carrier has reached the stop position, the reading mode of the mark sensor is reset, the barcode data read in the buffer is analyzed and converted into processable internal code format data, and the processing ends. To do.

[Problems to be Solved by the Invention]

In the conventional bar code reading control method in the printer, the bar code is read by the mark sensor 4 within a certain range regardless of the actual length of the bar code. Two
However, even if the area is limited to a part of the reading range of the mark sensor 4, the reading is continued beyond the bar code printing area 2 and a useless reading operation is performed. For this reason, there has been a problem that the read time becomes long, the read data amount increases, and the read data analysis processing time also becomes long.

Also, when trying to read only in the barcode printing area, it was necessary to calculate or measure the barcode width and specify it from the host.

The present invention aims at speeding up bar code reading without calculating or measuring the bar code width in areas other than the effective bar code printing area, performing no unnecessary reading operation, and suppressing the read data to the necessary minimum. With the goal.

[Means for Solving the Problems]

An object of the present invention is to detect the end of a bar code from the read data output from the mark sensor, immediately stop the movement of the carrier when the end of the bar code is detected, and end the bar code reading operation. Solved.

FIG. 1 is a principle block diagram of the present invention.

In FIG. 1, 1 is a printer sheet.

Reference numeral 2 is a bar code print area.

3 is a carrier of the print head.

Reference numeral 4 is a mark sensor for reading a bar code, which is mounted on the carrier 3.

A bar code reading control unit 5 is realized by software.

A reading mode flag 6 sets the reading mode of the mark sensor 4.

Reference numeral 7 is a white level determination function for determining the white level by reading the white background color of the printer paper 1 before the bar code reading is started.

Reference numeral 8 is white level data set by the white level determination function.

Reference numeral 9 denotes a bar code end detection function, which determines the bar code end when a white level section having a predetermined width or more, which is sufficiently larger than the maximum value of the white level section existing in the bar code, is detected. When the bar code end is detected, the carrier 3 is stopped and controlled.

Reference numeral 10 is a bar code data reading function.

Reference numeral 11 is a buffer for storing the barcode reading data.

Reference numeral 12 is a bar code analysis unit that converts the bar code data into data in the internal code format.

In the printer paper 1, s is the reading start position of the mark sensor 4, and e is the initial value of the carrier stop position,
e'is the carrier stop position changed by the barcode end detection according to the present invention. Also, a is the white level detection,
Reference symbol b indicates bar code detection, and reference symbol c indicates bar code end detection. Positions s and e are respectively initialized at the start of bar code reading control.

[Operation] In the principle configuration shown in FIG. 1, when the carrier 3 is moved from the left end to the right and reaches the reading start position s, the reading mode flag 6 is set to the reading mode,
The white level determination function 7 of the bar code reading control unit 5 detects the white level in the section a and sets the white level data 8.

Subsequently, the barcode data reading function 10 reads the barcode in the section b and reads the data into the buffer 11.
Further, during this period, the bar code end detection function 9 monitors whether the white level continues for a predetermined width or more, and detects the bar code end in the section c in which the white level continues for a predetermined width or more.

When the bar code end detection function 9 detects the bar code end, the bar code end detection function 9 changes the carrier stop position from e to e ', and immediately stops and resets the reading mode flag.

As a result, the buffer 1 by the barcode reading function 10
Reading of barcode data to 1 is stopped, and buffer 1
1 stores only the data read in the bar code detection section b and the bar code end detection section c.

Therefore, the barcode analysis unit 12 only needs to analyze almost valid data in the barcode printing area 2, and when the barcode printing area 2 is relatively small,
Processing time can be greatly reduced.

〔Example〕

FIG. 2 is a block diagram of a printer control circuit according to one embodiment of the present invention, and FIG. 3 is a flow chart of its bar code reading control.

In FIG. 2, 20 is a system bus.

21 is a CPU.

A ROM 22 stores various programs and control data for controlling the printer. In particular, it has a bar code reading control routine and a carrier interrupt processing routine related to the present invention. (Details will be described later according to the flow of FIG. 3).

A RAM 23 is provided with a buffer for reading bar code read data, a work area such as a carrier address counter, a read start position register, a carrier stop position register, a white level register, and a read mode flag.

Reference numeral 24 is a mark sensor for reading a bar code.

An amplifier 25 amplifies the analog signal output from the mark sensor 24.

26 is an A / D that converts an analog signal into a digital signal
It is a converter.

Reference numeral 27 is a carrier motor that controls the feeding of the carrier.

28 is a motor driver.

Reference numeral 29 is an I / O port for transferring drive data to the motor driver 28.

In operation, when the printer reads the bar code on the printer paper, the CPU 21 executes the bar code reading control routine of the ROM 22, the carrier interrupt processing routine, etc. to drive the carrier motor 27, set / clear the reading mode flag, It detects the white level from the output of the mark sensor 24, sets it in the white level data register, stores the bar code read data in the buffer, detects the bar code end and stops the carrier motor 27. The detailed operation of the circuit of FIG. 2 will be described below with reference to the flow of FIG.

In FIG. 3, (a) is the flow of the bar code reading control routine, and (b) in the broken line block is the flow of the carrier interrupt processing routine.

When reading a bar code, the bar code reading control routine of (a) is started.

First, the reading range and the carrier stop position are initialized. The reading range is defined by the reading start position and the carrier stop position, and is set in the corresponding registers in the RAM 23. In this case, the maximum value of the carrier stop position is set as the default value,
When the barcode end is detected later, the value is changed to a smaller value according to the detected position.

Then, the carrier transfer is started. The carrier movement control is performed by another routine (not shown), control data is set in the motor driver 28 via the I / O port 29, and the carrier motor 27 is driven.

Then, the reading start position is monitored, and when the reading start position is reached, the reading mode is set in the reading mode flag in the RAM 23. The carrier interrupt processing from the start of carrier movement to the setting of the read mode only updates the carrier address. When the read mode is set, the carrier interrupt processing routine of (b) becomes executable and the carrier interrupt (motor (Occurs at the timing of controlling the driver 28), first the RAM
The carrier address counter in 23 is updated, the address end is detected by ′, and if it is not the end, it is checked whether the white level is determined. If it is the end, the interrupt processing is ended. When the white level is not determined, that is, when the white level data is not set in the white level register in the RAM 23, the white level determination process is performed with.

In this white level determination processing, the mark sensor 24 reads the white area before the start of the bar code, averages several consecutive values of the read data output, and sets the resulting value as the white level.

On the other hand, if the white level has already been determined in step 1, it is checked whether or not the reading of the bar code has been started. If it has not started, the mark sensor 24
Of the output data is monitored, and when a value larger than the white level is detected, it is recognized that the reading of the barcode has started, and the read data is stored in the buffer of the RAM 23.

If the reading of the bar code is started at, the barcode end is checked to see if it is recognized. If it is recognized, the interrupt ends, but if it is not recognized, the mark sensor is detected. It is checked whether the output data value of 24 has a continuous white level of 0.3 inch width or more. If the white level is not continuous of 0.3 inch width or more, it is determined that the barcode is in the middle and the read data is buffered. If the white level is stored continuously for 0.3 inch width or more, it is judged as the bar code end, and the carrier stop position is changed by the RAM 23.
The content of the carrier stop position register in is updated to a predetermined value, the interrupt is ended, and the control is returned to the routine of (a).

In (a), the carrier movement is monitored based on the updated carrier stop position, and when the carrier stop position is reached,
Resets the read mode flag with, and analyzes the read data stored in the buffer with and ends.

〔The invention's effect〕

According to the present invention, when the serial printer performs the barcode reading operation, it detects the area where the barcode actually exists on the printer paper and reads it, and immediately after the barcode is finished, the carrier is stopped and the barcode is stopped. Since the code reading is completed, it is possible to read only the effective bar code printing area without paying attention to the bar code width. Also, the amount of read data is small, and the barcode analysis process can be performed efficiently.
The operating time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of a printer control circuit according to one embodiment of the present invention, and FIG. 3 is a flow chart of bar code reading control according to one embodiment of the present invention. FIG. 4 is a schematic diagram of a bar code reading control system in a conventional printer, and FIG. 5 is a flow chart of bar code reading control in a conventional printer. In FIG. 1, 1: Printer paper 2: Bar code printing area 3: Print head carrier 4: Mark sensor 5: Bar code reading control section 11: Buffer 12: Bar code analysis section

Claims (1)

[Claims] 1. A serial printer having a mark sensor mounted on a print head carrier, wherein a continuous white level section of a predetermined width or more is detected from the output signal of the mark sensor while the print head carrier is moving to detect a continuous white level section. Bar code end detection function to judge the end (9)
When the bar code end detection function (9) detects the harcode end while moving the print head carrier and reading the bar code on the printer paper using the mark sensor, the print head is immediately A bar code reading control method in a serial printer, characterized in that the movement of the carrier is stopped and the bar code reading operation is ended.