JPS58134774A - Abnormality-detecting system for head system in printer - Google Patents

Abstract

PURPOSE:To enable to detect an unexpected turning-ON or a failure of turning- ON of a controlling transistor for a driving magnet for a printing pin. CONSTITUTION:Input signals FiRE1-m and output signals FiRE of an input part 4 are taken in by controlling the part 4 at appropriate timings, the signals are carried onto a data bus (a), and it is examined whether or not the input and output signals have expected values. When printing is not conducted, strobe signals STB are not outputted, so that the output signals FiRE must not outputted. However, the signals might be outputted due to a breakage in the circuit by some cause. To check this, a *MASK is set into a logic ''1'' to release an interrupt mask, thereby enabling to interrupt by the signals FiRE.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention is capable of detecting that a driving transistor that causes a current to flow through a driving magnet coil that drives a print bottle is turned on at an unexpected time, and also detects when it should be turned on at an unexpected time. The present invention relates to a head system abnormality detection method in a printer device that is capable of detecting even when the head is not turned on at times.

[Prior art and problems]

As conventional print head abnormality detection methods, there are two known methods: one that protects circuit elements due to a fault, and the other that checks if a print head circuit element operates unexpectedly. However, the former has the disadvantage that if the number of bins in the print head increases, it must have a corresponding amount of heat, which increases the mounting space and increases costs.The latter has the disadvantage that when the transistor is expected to turn on, 5. Even if it does not work, it cannot be checked, the hardware is complicated and costly, and adjustments are required in some cases.

[Purpose of the invention] The present invention obviates the above-mentioned drawbacks.

The purpose of the present invention is to realize a circuit for quickly detecting an abnormality when it occurs in a drive transistor using simple m-ware, and to provide an accurate and reliable head system abnormality detection method for a printer device. There is.

[Structure of the invention]

Therefore, the head system abnormality detection method in the printer device of the present invention includes a microprocessor, an interface circuit controlled by a microphone processor connected to the microprocessor, a printing pin,
A driving magnet for driving the printing pin, a driving transistor for controlling the small current flowing through the driving magnet, a gate circuit for controlling the driving transistor, an output 777-) of the above-mentioned interface circuit, and the above-mentioned gate circuit. A printer device comprising a dot data line and a strobe signal line provided between the input side of the drive transistor, and a fire signal output circuit that outputs a fire signal indicating the state of the drive transistor; The fire signal line connects the output to the input port of the above interface circuit, and one input terminal connects to the above fire signal output circuit! ! a mask signal line connecting the other input terminal of the gate circuit for generating the fire interrupt signal and the output port of the interface circuit; an interrupt signal control circuit whose side is connected to the output of the gate (b) path for generating the fire interrupt signal and whose output side is connected to the interrupt terminal of the microprocessor; , a process of supplying data to the dot data line, a process of supplying a signal of a predetermined value to the strobe signal line, a process of supplying a signal having a value to inhibit fire interrupt V to the mask signal line, and printing. At a predetermined timing during the period, data on the fire signal line is read and recorded, and when printing is not being performed, a signal having a value that allows fire interrupt is supplied to the mask signal line. 1. It is constructed as follows: 1.% mold.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of an embodiment of a printer device according to the present invention, FIG. 2 is a diagram showing an embodiment of a driving magnet excitation part and a fire signal output circuit, and IN3 diagram is a diagram showing a strobe signal and FiRFj' It is a diagram showing the relationship between numbers.

In Figure 1, the first microphone is a four processor, 2 is an address decoder, 3 is an output port, 4 is an input port, 5 is a print head control circuit, 6 is a fire signal output circuit, 7 is a NANDl path, and 8 is an interrupt signal. In the control circuit, C represents a driving magnet for driving the printing bin, T represents a driving transistor, and D represents a diode.

The microprocessor 1 controls the entire printer device. Although not shown in FIG. 1, a ROM that stores programs and a RAM that stores data naturally exist. The address decoder decodes address information on the address bus, and selects a register in the output port 3 or a register in the input port according to the address information. When output port 3 receives a write signal, it writes the data on the data bus to the register specified by address decoder 2. When input port 4 receives a read signal, it writes the data on the data bus to the register specified by address decoder 2. Puts the contents of the specified register onto the data path. Turn on the print head. Drive transistor T
When turned on, the driving magnet (CK) current flows.

FIG. 2 shows the details of one embodiment of a portion consisting of a print head control circuit, a driving magnet, a driving transistor, and a fire signal output circuit. .

is a dot, data, Alm or A,... is a gate,
Tll or mx is a drive transistor Css or C□ drive magnet, Dll is a transistor, B is a diode, 9-1 or 9-Ku is a TTL level conversion circuit,
10-1 to 1G-4 indicate an inverter and an OR circuit 11a, respectively. All drive magnets are chicken x
There is one dot data, and the dot data with no total Fi is added to the base of the corresponding driving transistor. If the dot data is a logical "]", the corresponding drive! Current flows through the magnet. The collectors of one driving transistor in each block are coupled via a diode, and this coupling point is connected to the input side of the corresponding TTL level conversion circuit. Now, when any one of the driving transistors T, 1 to T11 is turned on, the input of the TTL level conversion IS9 becomes the logic rOJ.

However, it is assumed that the low level is logic "0".

When the TTL level conversion circuit 9-1 outputs the logic rOJ, the inverter 10-1 outputs logic "1". The output of the inverter 10-1 becomes FiREla. OR
The FiRE1 to y=Rw book is input to the circuit 11, and its output is FLRE4! number.

First - as shown, the FIRE signal and *MASK
The signal is input to the NAND circuit 7. *When the MASK signal is logic "OJ", the output of NAND circuit 7 is logic "L"
”. *When MASK signal is logic rlJ □Kv
When the tnE signal outputs a logic "1", the output of the NAND circuit 7 becomes a logic "0", and this signal is input to the interrupt signal control circuit 8. If this signal is selected by the interrupt control circuit 8, 1 interrupt request *iRQ becomes logic "O".

Next, the operation of the present invention will be explained. When performing a printing operation, the *MASK signal is set to logic "0" to prevent interrupts from occurring, and the print data DAT
Connect A s t or DATA to output port 3
ILr & Toshi sends out strobe signal 5TBt'. When Jin
The microprocessor 1 stores in advance whether or not there is dot data of logic "1" in each data block in a register.
If there is dot data of ``, the pg RE' of that block is displayed for one period when the strobe signal is sent.
It is expected that (I ML t =l−L...drop) will be turned on. Therefore, in the present invention, during printing, data
piRgl per block.

yinE2. ...By monitoring the FjREm signal, it is attempted to check whether the driving transistor is operating correctly.

FIG. 3 shows the relationship between the strobe signal 8TB and the FiRE signal. First, in the data block there is a logical
If there is even one dot data of "1", the v fog REi signal corresponding to that data block is set at timing P.
The logic should be "0" at I and P4, and the logic "J" at timings P2 and P3. Furthermore, if all the dot data in the data block are logic "0", the corresponding FiREi signal should become logic "0" no matter which timing from timing P1 to P4 occurs.

Therefore, in the present invention, the input ports 4 are controlled at appropriate timing to provide FiRE1, 2. ...takes the associate signal and FARE signal and puts it on the data path, yia
El, 2. . . . It is checked whether the 凰 signal and the viRE signal have the expected values. Also, since the strobe signal STB is not being sent when printing is not being performed, F! The RE signal should not be output either, but there is a possibility that the circuit may be damaged for some reason and output, so to check this, cancel the interrupt mask by applying *MAS K to the logic rlJ, and cancel the interrupt mask by the FIRE signal. Enable interrupts.

[l! Light effect〕

As is clear from the above description, according to the present invention, since a check by a program and a check by an interrupt are used, a highly reliable check can be realized with simple hardware. It has the effect of increasing the degree of confession because it is controlled and paid.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall configuration of one embodiment of the printer device according to the present invention, FIG. 2 is a diagram showing one embodiment of the driving magnet excitation part and the fire signal output circuit, and FIG. 3 is a diagram showing the strobe signal output circuit. FIG. 3 is a diagram showing the relationship between the piRE signal and the piRE signal. l...Microprocessor, 2...Address e decoder, 3...Output port, 4...Input port, 5...
...Print head control circuit, 6...Fire signal output circuit. 7... NAND circuit, 8... Interrupt signal control circuit,
C... Driving magnet that drives the printing bin, T...
・Drive transistor, D...diode. Patent Applicant: Usatsuk Electronic Industry Co., Ltd. Representative Patent Attorney: Yoshibe Kyotani and 1 other person: '1: 57B Ya3 Figure 1: □.

Claims (1)

[Claims] A microprocessor, an interface circuit connected to the microprocessor and controlled by the microprocessor, a printing bin, a driving magnet for driving the wrinkle printing bin, and a driving magnet for driving the % cough drive. A drive transistor that controls the current, and a drive transistor that controls the current.
A printer device includes a gate circuit to control, and a dot data line and a strobe signal line provided between an output port of the interface circuit and an input side of the gate circuit. a 7-year signal output circuit that outputs a 7-year signal indicating the state of the driving transistor; a fire signal line that connects the output of the fire signal output circuit to the input port of the interface circuit; 7 connected to the above fire signal output circuit
A gate circuit for generating the fire interrupt signal, a mask signal line extending 11M between the other input terminal of the gate circuit for generating the fire interrupt signal and the output port of the interface circuit, and a mask signal line whose input side is for generating the fire interrupt signal. The output of the gate circuit KII! and an interrupt main signal control circuit connected to the interrupt terminal of the microprocessor and the output side of the microprocessor, and the microprocessor company supplies the dot data IIK data when printing. processing and. A process of supplying a signal with a predetermined value to the strobe signal line, a process of supplying a signal with a value to inhibit the 7-year interrupt to the mask signal line, and a process of supplying a signal with a value to inhibit the 7-year interrupt to the mask signal line, and the above at the required timing during the printing period. The apparatus is characterized in that it is configured to perform a process of reading data on the fire signal line, and when not printing, perform a process of supplying a signal having a value that permits a 7-tier interrupt to the mask signal line. Head system abnormality detection method in printer equipment.