JPH0127861B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal barcode label printing device.

Traditionally, printing devices that use thermal heads include facsimile machines and ticket vending machines, but these often print characters, figures, etc., and even if one of the many heating resistors is damaged, If it can be visually read, there is no problem in practical use and there is no major problem.

However, when printing barcodes using this type of heat-sensitive head, if even one heating resistor is damaged, one of the barcodes may be missing or the thickness may become thinner, making it difficult to print correctly. It is impossible to print, and when it is read, it may be misread, or it may become unreadable.

The present invention has been made in view of these points, and provides a thermal bar that detects whether the heating resistor of the thermal head is operating normally and prevents abnormal barcode printing. The purpose is to obtain a code label printing device.

In the present invention, a plurality of heating resistors arranged in a straight line are wired in a matrix to a common electrode selection circuit and an image signal selection circuit, and the energization state of the heating resistors is detected when the image signal selection circuit is not operating. Since the abnormality signal generation circuit generates an abnormality signal if there is even one abnormality, it is possible to perform accurate printing even when printing barcodes, thereby increasing the reliability of printing. It is composed of

An embodiment of the present invention will be described based on the drawings.
First, a display keyboard 2 and an external device 3 such as a scale are connected to the CPU 1, as well as a ROM 4 that generates barcode patterns and character patterns. A common electrode selection circuit 5, an image signal selection circuit 6, and a pulse motor drive circuit 7 are connected to the CPU 1, and a thermal head 8 is connected to the common electrode selection circuit 5 and the image signal selection circuit 6. , a pulse motor 9 is connected to the pulse motor drive circuit 7. Then, the above
A pulse generation circuit 10 is connected to the CPU 1, and an abnormality detection circuit 1 is connected between the pulse generation circuit 10 and the image signal selection circuit 6 and the thermal head 8.
1 is connected, and this abnormality detection circuit 11 is connected to the
Connected to CPU1.

Next, a label 13 made of thermal paper is attached to the long mount 12, and this mount 12 is attached to the platen 1.
4, the heat-sensitive head 8 is bonded, and the mount 12 is bent by a pin 15 to peel off the label 13, and the peeled label 13 is placed on a peeling table 16 with its adhesive side facing up. It is set up so that it stands still.

An example of the label 13 printed in this manner is as shown in FIG. 3, and consists of a bar code 17 and characters 18 numerically indicating its contents and price in the paper feeding direction.

Next, FIG. 4 shows details of the display keyboard 2. That is, the display section 19 is provided with a flag column, a code 1 column, a code 2/price column, a C/D column, and a quantity column. Above this display section 19 are an error display section 20 and a label end display section 21. , a label detection display section 22 is provided. Furthermore, a changeover switch 23, a paper feed key 24, a numeric keypad 25, and a function key 26 are provided below from the left side. The changeover switch 23 has a barcode 1
Select the length of 7, select the number of digits of barcode 17, turn on connection with external device 3,
It consists of things such as things to turn off, things to decide whether to print labels continuously, things to select label size, etc. Further, the function key 26
is test key 27, flag key 28, code 1
Setting key 29, code 2/price setting key 30, quantity setting key 31, stop key 32, erase key 3
3. It consists of a print key 34.

The electric circuit around the heat-sensitive head 8 will now be described with reference to FIG. First, the thermal head 8 has heating resistors 35 divided into three groups, _R1 to _R4 , _R5 to _R8 , and _R9 to _R12 , as indicated by COM1, COM2, and COM3. . The number of these heating resistors 35 is actually larger, and they are arranged in a straight line. and,
The common electrode selection circuit 5 is connected to the heating resistor 35 via a drive circuit 37 having three transistors 36 operated by inputs indicated as . Further, the image signal selection circuit 6 includes:
It is connected to a drive circuit 39 having four drivers 38 operated by inputs indicated as , , , and these drivers 38 are connected to a diode 40
It is connected to the heating resistor 35 via.
Next, the driver 38, that is, the heating resistor 35 is connected to the diode 41 of the abnormality detection circuit 11. These diodes 4
1 is maintained at a constant voltage by a resistor 42, and
It is connected to the input side of the gate 45 via a resistor 43 and a Zener diode 44. This gate 4
The output of 5 is connected to the gate 46 together with the output of the pulse generating circuit 10, and the output of this gate 46 is connected to the CPU 1.

The gate 46 and the pulse generation circuit 10 form an abnormal signal extraction circuit.

In this configuration, normal printing operation is performed when, in the timing chart of Figure 6, some signal is output during the timing indicated by the dotted line when the common electrode signal is generated. As a result, the heating resistor 35 is energized and the bar code 17 or characters 18 are printed.

Therefore, immediately after the signals , , and before the signals .
More pulses are generated. At this time, if all the heating resistors 35 are normal, all inputs to the gate 45 are at H level, and the output of the gate 45 is at L level. However, if any one of the heating resistors 35 is damaged, one of the inputs to the gate 45 will be at the L level, and as a result, the output of the gate 45 will be at the H level. Therefore, by taking the output of the pulse generating circuit 10 and the period, the gate 4
6 opens and generates an abnormal signal.

Next, the processing routine of this embodiment will be explained based on FIGS. 7 to 9. First, at the start, it is initialized and returns to key processing. This key processing routine starts by pressing the print key 34, data processing is performed by turning on the print key 34, and COM1
The electrode is turned on, a pulse is generated from the pulse generating circuit 10, and a check is made to see if the heating resistor 35 is normal. That is, the signal is checked. If it is abnormal, proceed to the explanation below; if it is normal, proceed to
The image signal for COM1 is set, and the pulse motor 9
is driven. In this way, the COM2 electrode,
Each of these electrodes has a check part for a heating resistor 35, and when an abnormality occurs, a signal is output. This results in
The operation as shown in FIG. 9 proceeds. That is,
In this case, the COM1 electrode turns OFF, the error lamp lights up, and the error display section 20 lights up.
"E1" is displayed in the flag column of the display section 19, and the other columns are turned off. And erase key 3
By pressing 3, the error lamp goes out, and the display "E1" on the display section 19 also goes out. and,
The same applies when a signal such as or
It becomes "E2" or "E3".

In the present invention, a common electrode selection circuit and an image signal selection circuit are matrix-wired to a thermal head equipped with heating resistors arranged linearly in a plurality of blocks as described above, and the image signal is Since an abnormality detection circuit is provided to detect an abnormality in the heating resistor when the selection circuit is not operating, it can be used in cases such as bar codes that require strict operation of all the heating resistors. This is the most suitable method, as it prevents erroneous readings or unreadable readings, and it is easy to detect abnormalities every time the common electrode selection circuit switches. This has the advantage that the operation can sometimes be stopped immediately.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is an overall block diagram, Fig. 2 is a side view of the printing mechanism, Fig. 3 is a plan view of the label, and Fig. 4 is a plan view of the display keyboard. 5 is an electrical circuit diagram of the main part, FIG. 6 is a timing chart, and FIGS. 7 to 9 are flow charts. 5... Common electrode selection circuit, 6... Image signal selection circuit,
8...Thermal head, 11...Abnormality detection circuit, 35...Heating resistor.

Claims (1)

[Claims] 1. A thermal head in which a plurality of linearly arranged heating resistors are divided into a plurality of blocks, and a common electrode selection circuit and an image signal selection circuit are wired in a matrix to the heating resistors of each of these blocks; an abnormality detection circuit that detects a damaged state and generates an abnormal signal based on the energization state of the heating resistor of each block when voltage is applied by the electrode selection circuit; and an image signal selection circuit that generates an abnormal signal when voltage is applied by the common electrode selection circuit. A thermal barcode label printing device comprising: an abnormality signal extraction circuit that takes out the output of the abnormality detection circuit at a timing when the abnormality detection circuit is not operating; and an error display section that displays the generation state of the abnormal signal.