JPS6361188B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing test method for thermal barcode printing when barcode printing is performed using a thermal printing method.

Conventional printing devices using thermal heads include facsimile machines and ticket vending machines. Since the objects to be printed are characters and figures, it is practically impossible to print even if a part of the dot-shaped printing, for example, one of the heating resistors arranged in a straight line, breaks down and becomes impossible to print. There are cases where you don't notice the missing dots for any reason. However, when trying to print a barcode using this method,
When bars are formed along the paper feed direction, if there is a missing dot, one bar will be missing or the thickness will change, leading to misreading or impossible reading. It is something. Possible causes of such printing omissions include a defect in the heating resistor of the thermal head, a defect in the drive circuit, and the like.

The present invention has been made in view of the above points, and an object of the present invention is to provide a printing test method for printing thermal barcodes that can easily detect missing dots by visual inspection.

In the present invention, by pressing a test key, the driver of the heat generating resistor selection drive circuit is sequentially driven to print diagonal lines of each group of the heat generating resistors in parallel, and the group of the heat generating resistors located in the previous stage is printed in parallel. The diagonal lines of the group of heat generating resistors located at the rear stage are made to be continuous with the diagonal lines of the group of heating resistors located at the subsequent stage. Therefore, if any of the heating resistors is damaged, the image signal selection circuit or the heating resistor selection drive circuit is defective, the common electrode selection circuit or the group selection drive circuit is defective, etc. Even if there is a missing dot, it is easy to find it.In particular, since the diagonal line of the group of heating resistors located in the front stage is made to be continuous with the diagonal line of the group of heating resistors located in the rear stage, the edge of each group can be easily found. The structure is such that even if the heating resistor located in the section is damaged, the abnormal condition can be easily found.

An embodiment of the present invention will be described based on the drawings. First, a display keyboard 2 and an external device 3 are connected to the CPU 1, which is the control unit.
1 is connected to a ROM 4 that generates character patterns and barcode patterns. And said
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. Further, a pulse motor 9 is connected to the pulse motor drive circuit 7.

Next, labels 11 made of thermal paper are pasted on the elongated mount 10 at regular intervals, and the labels 11 are inserted between the platens 12 to which the heat-sensitive head 8 is joined. The label 11 is bent and peeled off, and the label 11 is set to rest on a peeling table 14 with the adhesive side facing up.

In addition, the one shown in Figure 3 is the printed label 1
This shows an example of printing No. 1, which consists of a bar code 15 that is long in the paper feed direction and characters 17 displaying its contents and price 16.

Therefore, the contents of the display keyboard 2 are
This is shown in the figure, and includes a display section 18 that displays flags, code 1, code 2/price, C/D, quantity, etc. in a horizontal line, an error display 19, a label end display 20, and a label detection display 21. At the bottom, there are numeric keypad 22 and function key 2.
3. A paper feed key 24 and a changeover switch 25 are provided. The function key 23 has a test key 26, and other keys include a flag setting key 27, a code 1 setting key 28, a code 2/price setting key 29, a quantity setting key 30, a stop key 31, an erase key 32, print key 33
etc. exist. The changeover switch 25 also includes a bar length changeover switch 34 that changes the length of the barcode 15 to 8 mm or 16mm, and a bar digit number setting switch that changes the number of digits of the barcode 15 to 13 or 8. Turn on the connection between 35 and the external device 3,
The size and size are determined by the connection switch 36 that turns OFF, the continuous issue switch 37 that determines whether or not to issue labels 11 continuously, and the label 11 used.
It consists of a label size changeover switch 38 that sets the label size to small.

Next, what is shown in FIG. 5 is an example of electrical connection to the thermal head 8. In FIG. First, it is assumed that the heat-sensitive head 8 has heating resistors 39 divided into three groups of eight resistors R1-8, R9-16, and R17-24. A group selection drive circuit 41 including three transistors 40 labeled Q ₁ , Q ₂ , and Q ₃ is connected to the common electrode selection circuit 5 , and this group selection drive circuit 41 is connected to the thermal head 8 . It is connected. Next, the image signal selection circuit 6 has 8
A heat generating resistor selection drive circuit 43 consisting of drivers 42 is connected, and the drivers 42 of this heat generating resistor selection drive circuit 43 are commonly connected to the heat generating resistors 39 of the same rank in each group via a diode 44. has been done. That is, in the state shown in FIG. 5, the connection state of each driver 42 is R ₁ ,
A combination of R ₉ , R ₁₇ , R ₁₀ , R ₁₈ , R ₃ , R ₁₁ , R ₁₉ . . . is connected to the heating resistor 39 of each group.

As shown in FIG. 6, the switching of the common electrode selection circuit 5 occurs during the period _t4 .
At the timing of t ₁ , the transistor 40 of Q ₁
The transistor _Q2 turns on at the timing _t2 , and the transistor _Q3 turns on at the timing _t3 . As a result, t ₁ ,
If there is a signal from the image signal selection circuit 6 during the timings t ₂ and t ₃ , the corresponding heating resistor 39 is energized, thereby printing the necessary barcode 15 and characters 16 .

Normal printing is performed in this way, but when the test key 26 is pressed, the heating resistor 39 starts to be energized from R1, R9, R17, then R2, R10, R18, R3, R11, R1.
The process proceeds in the order of 9, R4, R12, R20...
Therefore, when there is no abnormality in each part, a diagonal line with no missing parts will be drawn as shown in FIG.

However, there are three reasons why print defects occur:

(i) When any of the heating resistors 39 is damaged.

(ii) When the image signal selection circuit 6 or the heating resistor selection drive circuit 43 is defective.

(iii) Common electrode selection circuit 5 or group selection drive circuit 4
If 1 is defective.

Therefore, first of all, when any one of the heating resistors 39 is damaged, a situation as shown in FIG. 8 occurs. This is a case where the heating resistor 39 of R9 is damaged, and it is clear that the failure is due to the heating resistor 39 because the diagonal lines are missing and they are at the same position in the vertical direction. Next, in the case of the above-mentioned cause (ii), for example, if the second driver 42 in the drive circuit 43 fails, the state shown in FIG. 9 will occur, and the shaded area will be missing. At this time, it is clear that the driver 42 is malfunctioning because the missing portion occurs in the horizontal direction. Furthermore, in the case of the above-mentioned cause (iii), for example, when the second transistor 40 fails, one of the three diagonal lines is missing as shown in FIG. Therefore, it is clear that this is a failure on the drive circuit 41 side.

In this way, when the test key 26 is pressed, the CPU 1 is programmed to print diagonal lines, and by looking at the missing shaded area, it is obvious which part is abnormal. Become.

In the above description, the paper feed key 24 was provided on the display keyboard 2. This paper feed key 24 is used when newly setting or removing the mount 10, and when pressed once, the label 11 is fed by one sheet. It is set so that it can send the length. However, this paper feed key 2
4 may be abolished and the test key 26 may be replaced with it. In this case, it is preferable that the operational functions of each part be automatically checked in advance. Of course, if the paper feed key 24 side is provided with a diagonal line printing function, the test key 26 provided in the function key 23 becomes unnecessary.

As described above, in the present invention, by pressing a test key, the driver of the heat generating resistor selection drive circuit is sequentially driven to print the diagonal lines of each group of the heat generating resistors in parallel, and the heat generating element located in the previous stage is printed in parallel. Since the diagonal line of the group of resistors and the diagonal line of the group of heating resistors located in the subsequent stage are made to be continuous, when any of the heating resistors is damaged, the image signal selection circuit or the heating resistor selection drive circuit is defective,
In any case, such as when the common electrode selection circuit or the group selection drive circuit is defective, missing dots can be easily found, especially between the diagonal line of the group of heat generating resistors located in the previous stage and the part located in the rear stage. Since the diagonal lines of the heating resistor groups are continuous, even if the heating resistor located at the end of each group is damaged, the abnormal condition can be easily found, which makes it easier to print barcodes. When used for this purpose, the code does not become erroneous or unreadable, and has the advantage that the printing condition can be inspected to ensure extremely reliable printing.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is an overall block diagram, Fig. 2 is a longitudinal cross-sectional side view of the printing section, Fig. 3 is a plan view of the label, and Fig. 4 is a plan view of the display panel. Figure 5 is an electrical circuit diagram centered on the heat-sensitive head part, Figure 6 is a timing chart, Figure 7 is a plan view of a printing example showing normal operating conditions, and Figures 8 to 10 are each FIG. 3 is a plan view of an example of printing indicating an abnormal state. DESCRIPTION OF SYMBOLS 1...Control part, 5...Common electrode selection circuit, 6...Picture signal selection circuit, 8...Thermal head,
11...Thermal paper, 39...Heating resistor, 41...
Group selection drive circuit, 42...driver, 43...
Heating resistor selection drive circuit, 44...diode.

Claims (1)

[Claims] 1. A large number of heat generating resistors arranged in a straight line, a group selection drive circuit and an image signal selection circuit that divide these heat generating resistors into a plurality of groups and selectively connect them to a common electrode selection circuit. A heat-sensitive head comprising a heat-generating resistor selection drive circuit using a driver connected to the heat-generating resistors of the same rank in each group via a diode, and a thermal paper placed in a direction perpendicular to the heat-generating resistors. It has a paper feeding mechanism that moves the paper, and a control unit that prints a predetermined dot pattern on the thermal paper, and when a test key is pressed, the driver of the heating resistor selection drive circuit is sequentially driven to print the heating resistor. The diagonal lines of each group of heating resistors are printed in parallel, and the diagonal lines of the group of heating resistors located at the front stage are continuous with the diagonal lines of the group of heating resistors located at the rear stage. Printing test method for code printing. 2. A printing test method for thermal barcode printing according to claim 1, characterized in that the test key also serves as a paper feed key and the paper feed key is omitted.