JPS60210485A - Operation inspecting device for thermal printer - Google Patents

Abstract

PURPOSE:To detect an abnormal condition in a heating circuit part, by a method wherein printing data for a new line are inputted into a shift register, while printing data for the preceding printing are inputted into a comparing circuit to be compared with an output from the final stage of the shift register. CONSTITUTION:In response to a printing command, printing data are inputted from a printing data outputting part 22 into a printing memory 25 under the control of a printing controller 18. The first clock pulse CLK1 and the second clock pulse CLK2 are alternately outputted to output new printing data and the data of the previously printed line, respectively. The pulse CLK1 designates an address 3, while the pulse CLK 2 designates an address 2, and when inputting of a one-line amount of data is completed the contents of the shift register 20 are inputted into a latch circuit 17 at one stroke, and AND gates 16 are opened to pass an electric current to heating elements 14, thereby heating. When the heating element 14 is broken, a light-emitting element 32 does not emit light at the current-passing timing, so that the abnormal condition is detected.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an operation inspection device for a thermal printer that performs thermal printing by selectively energizing a large number of heating elements.

In general, there are two types of thermal printing using thermal printers: a method that uses thermal paper and a method that prints on plain paper using an ink ribbon coated with heat-melting ink. It is clearer than those made by other printing devices, and the size of the heating element has improved as semiconductor technology has improved, making it possible to print B DOT/screams, making it possible to express letters and images down to the minute details.

Therefore, not only in the field of office equipment such as facsimiles, but also
With the development of POS, it has also begun to be used in the field of barcode printing.

Therefore, the structure of the barcode is JAN, UPC, EA.
In standards such as N, numbers are composed of 7 modules, for example, the composition of 7 modules for odd parity of the number 5 is 0110.
It is expressed as 001 (black is 1). Here the magnification is 1
Multiplied by 0.33 +nm is 1 module, resulting in white or black. These 7 modules gather 13 digits to form a standard version, which is read by a laser scanner or the like and registered in a register.

Therefore, the problem with barcodes is that if one heating element is destroyed, that is, when it is heated, the number 5 (for example, 1110001 becomes 00001 and 011000 becomes 0110001)
It changes to something like 0, resulting in a reading error. However, barcodes have percentage calculations, so they are rarely read as other numbers.
Furthermore, since there are rules for odd and even parity, two black odd parity errors occur.

In this way, even if there is an error in the IDOT of one heating element, the barcode is printed, so the operator cannot discover the abnormality, and it is not necessary to check the condition of the bar frequently. Since this process takes a long time, human visual inspection is impossible.

In addition, even if the heating element is normal, if there is an abnormality in the circuit that controls the operation of the heating element, it will not be possible to generate heat normally, and as in the case described above, the barcode cannot be printed correctly. It is impossible to do so.

OBJECTS OF THE INVENTION An object of the present invention is to provide an operation inspection device for a thermal printer that can detect abnormalities in a circuit portion that causes a heating element to generate heat.

Summary of the Invention The present invention connects a shift register that stores heat generation data to a heating element to a heat generation control circuit, connects its final output to a comparison circuit, and outputs data from a print memory that stores multiple lines of print data. Nori Daiichi Nori. The print data of the new line and the print data printed last time are generated alternately for each bit by the light cruise and the second quack pulse, and the print data of the new line is input to the shift register, and the print data printed last time is compared. It is input to the circuit and compared with the output of the final stage of the shift register, and if there is a discrepancy, it is assumed that there is an abnormality in the shift register and an abnormality signal is generated to the abnormality detection circuit. By connecting a destruction detection circuit, it is configured so that abnormalities in the heating element itself can also be detected.

Embodiment of the Invention An embodiment of the present invention will be explained based on the drawings. This embodiment relates to a label printer. First, rectangular labels (2) are pasted on a long backing paper (1) at equal pitches, and this backing paper (1) is wound into a roll and held in a label supply unit (3). has been done.

Further, the direction of the mount (1) is changed by a direction changing roller (4), and reaches the label peeling plate (6) via the platen (5). At this position of the label peeling plate (6), the mount (
1) is sharply bent to send out the label (2) forward, and the mount (1) is wound around a take-up shaft (8) via a roller (7). This winding shaft (8) is the winding motor (9)
The platen (5) is driven by a feed motor αO. Next, the platen (
The upper part of the label 5) is pressed by a thermal head α force with a constant pressure, and in front of the label peeling plate (6) is a label detector (c) for detecting the presence or absence of the label (2).
is provided. This label detector α detects the leading edge of the label (2), and its detection is used as a reference signal for determining the stop position during label feeding.

However, what is shown in Figure 2 is a printed label (2)
This shows an example, where A is the label feeding direction in 9 directions,
B is the arrangement direction of the heating elements, which will be described later.

Therefore, the barcode αj is printed by feeding the label while the heating element is energized, and is a continuous line.

Next, the internal structure of the thermal head α force and the circuit connected thereto will be explained based on FIG.゛First,
A large number of heating elements 04 are arranged in a straight line, and each of these heating elements α→ is connected to a transistor αO for controlling energization thereof. The gate αQ of the transistor is connected to this transistor 0υ, and these AND gates) (
A latch circuit 0η is connected to the input side of lfe, and a print controller Oe is also connected via an ENB terminal. The heat generation control circuit OI is formed by the transistor (to), the AND gate a0, and the latch circuit 0η.
is formed. Further, a shift register is connected to the latch circuit αη. This shift register (
1) is connected to a PIX IN terminal to which print data is sent and a CLK terminal to which a first clock pulse is sent. Further, the final stage output section of the shift register is connected to the input side of an exclusive OR (c) which serves as a comparison circuit via a PIXOUT terminal.

Next, an AND gate (in which the print data output unit Q and the print controller α peak are connected to the input side) is provided, and this AND gate (c) is connected to the character generator conversion circuit (c) to print data. Memory (c) is connected. This print memory (c) is addressed by the print controller (to). That is, the print memory (c) stores multiple lines of print data, and outputs a newly printed line or outputs a previously printed line by being addressed in response to a clock pulse. A choice is made. Here, the term "line" refers not to a line of completed characters, but to a line of dots forming a character. The data output section of the print memory (c) is connected to the shift register (1).
PIX IN terminal and the above exclusive OR@1)
is connected to the input side of the This exclusive O
The output side of RBη is connected to an AND gate (c) together with the second clock pulse output part of the print controller (c), and this AND gate (c) is connected to a data check circuit (a) as an abnormality detection circuit. has been done.

Next, the common terminal VTR of the heating element α4 is connected to a power source (E) via a control element (C) whose ON-OFF state is controlled by the print controller α→. A heating element destruction detection circuit (g) is connected in parallel to the control element (c). That is, a series circuit of step-down resistor 0 and light emitting element 0 is connected to the control element (c). A light-receiving element 0 is provided opposite to the light-emitting element 0, and the light-receiving element 01 has a detection terminal (b).
is connected. Further, this light receiving element 03 is connected to the printing controller (2) via a resistor (c).

In such a configuration, when a print command is received, print data is input from the print data output section ■ to the print memory (C) via the palm gate (C) and the character generator conversion circuit (C) under the control of the print controller 0→. be done. Then, the first clock pulse CLKI and the second clock pulse CLK2 are outputted alternately. Here, CLK
I is for inputting new print contents to the shift register (E) K, and CLK2 is for outputting the data of the previously printed line.

Now, referring to FIG. 4, an example of printing and checking on the third and fourth lines will be explained. The print data is “10
111J, and the portion marked with an X actually contains data, but the explanation would be complicated, so it is written here to omit the explanation. Therefore, in FIG. 4, only the movement of rlollJ is shown.

First, in the second line printing, address 3 is specified by CLKI, and address 2 is specified by CLK2. Therefore, rlollJ is output at the timing of address 3 and stored in the shift register. - When the input of the character is completed, the contents of the shift register (1) are input at once to the latch circuit αη by the staple signal, and the contents of the shift register (1) are input to the latch circuit αη by the enable signal.
The ND gate αQ is opened, the heating element α→ is energized, and printing is performed.

Then, when the fourth line is printed, CLKI is set to address 4.
, and CLK2 specifies address 3. At this address 3, the data printed on the previous line is output,
At address 4, data to be newly printed is output. Therefore, every time new data is input at address 4, the previous data is output from the final output stage, and at the timing of address 3 by CLK2, an exclusive OR@1
) is input with data from the print memory (c) and the final stage output from the shift register. Therefore, if they match, no output will be output from exclusive OR (c), but if they do not match, K will output, and CL
The data check circuit (a) operates at the timing of K2 and stops the operation of each part. As a result, the issuance of labels (2) that may be misread, such as barcodes, is temporarily suspended.

Further, when no printing operation is being performed, the control element (c) is turned off. In this state, an energization signal is sequentially applied to the heating elements a4 one by one. If normal, the light emitting element 02 emits light each time. At this time, since the step-down resistor G force exists, the heat generated by the heating element 04 does not increase to the extent that the label (2) becomes colored. If the heating element 0 is turned off, the light emitting element 0 will not emit light at the timing of energization. Therefore, an abnormality signal is output from the detection terminal 0, and an abnormality in the heating element α→ is detected.

Effects of the Invention The present invention stores print data line by line in a shift register and generates heat by energizing a heat generating element using a heat generation control circuit, in which a print memory is provided to store print data of a plurality of lines. , the first clock pulse inputs the data of the new print line into the shift register, and the second clock pulse outputs the data of the previously printed line from the print memory.
The output of the final stage of the shift register and the data of the previously printed line can be matched bit by bit, and by comparing the two with a comparator circuit, it is possible to check whether the shift register is operating normally. By connecting a heating element destruction detection circuit to the control element connected to the heating element, it is possible to detect abnormalities in the heating element itself. This allows for accurate printing of barcodes, etc.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side view of a part of the label printer, FIG. 2 is a plan view of the label, FIG. 3 is a circuit diagram, and FIG. 4 is a timing chart. . 14... Heating element, 18... Print controller, 19
... Heat generation control circuit, 20 ... Shift register, 21
...Exclusive $QR (comparison circuit), 25...
Print memory, 27... Data check circuit (abnormality detection circuit), 28... Control element, 30... Heating element destruction detection circuit

Claims (1)

[Claims] 1. A shift register in which a large number of heating elements that generate thermal energy for recording by being selectively energized are arranged in a straight line, and heat generation data for each of these heating elements is stored. In a thermal printer equipped with a heat generation control circuit that simultaneously controls the heat generation operation of the heating element according to the contents stored in the shift register, a print memory that stores multiple lines of print data is provided, and a data output section of this print memory is provided. is connected to the input of the shift register, and the final output of the shift register is connected to the input of the connected comparison circuit, and a first clock pulse generates print data for a new line from the print memory. A print controller is provided which inputs the data into the shift register, generates the print data of the previously printed line from the print memory using a second clock pulse, and outputs the output of the comparison circuit to the abnormality detection circuit. An operation inspection device for thermal printers. 2. A large number of heating elements that generate thermal energy for recording by being selectively energized are arranged in a straight line;
In a thermal printer equipped with a shift register that stores heat generation data for each of these heat generating elements and a heat generation control circuit that simultaneously controls the heat generation operation of the heat generating elements according to the stored contents of this shift register, it is possible to print multiple lines of print data. A print memory for storing data is provided, the data output of the print memory is connected to the input of the shift register, and the final output of the shift register is connected to the input of the connected comparison circuit, and the output of the first clock pulse is connected to the input of the connected comparison circuit. Then, print data for a new line is generated from the print memory and inputted to the shift register, and at the same time, print data for the previously printed line is generated from the print memory by a second clock pulse, and output from the comparison circuit. A print controller is provided that outputs the error to an abnormality detection circuit, and a control element that turns ON during normal recording is connected to the common terminal side of the heating element, and destruction of the heating element is individually detected in parallel with this control element. An operation inspection device for a thermal printer, characterized in that it is connected to a heating element destruction detection circuit.