JP2765849B2 - Printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printer that is frequently used as one of peripheral devices such as a computer and a word processor.

(Prior Art) A printer that is frequently used as one of peripheral devices such as a computer receives data from the computer or the like,
Print various information.

FIG. 2 shows a block diagram of such a conventional printer.

The figure shows a microprocessor 1, a read only memory (ROM) 2, a random access memory (RAM) 3, a control circuit 4, an interface driver / receiver circuit 5, and a drive system connected thereto. 6 is comprised.

The microprocessor 1 is a circuit that controls and manages the entire printer. This circuit includes a driving system 6 described later.
Status flag 1a consisting of registers for controlling power supply
And an alarm timer 1b composed of a counter. The ROM (read only memory) 2 is a read-only memory that stores programs, character font patterns, and the like. RAM (random access memory) 3
Is a memory for temporarily storing data output from the control circuit 4 and capable of performing writing and reading.
The control circuit 4 is a circuit that manages control of the interface driver / receiver circuit 5 and maintenance of operation of the drive system 6. The interface driver / receiver circuit 5 is a circuit for exchanging data with a computer (not shown) via an interface. The drive system 6 includes a drive circuit 7, a power supply 8, and a movable part 9. The drive circuit 7 is a circuit that controls supply of power to the movable part 9. The power supply 8 is a circuit that supplies power to the movable part 9 via the drive circuit 7. Movable part 9
Are the print head 10, the space motor 11, and the line feed motor
12 and a sensor unit 13. Print head 10
Prints characters and the like on a printing medium such as printing paper (not shown). The space motor 11 is a motor that drives the print head 10. The sensor unit 13 includes a slit encoder 13a and a sensor 13b. The slit encoder 13a rotates in conjunction with the space motor 11,
It is a disk-shaped plate with many slits opened radially. The sensor 13b includes a light emitting element and a light receiving element which are arranged to face each other with the slit encoder 13a interposed therebetween.
The rotation of the space motor 11, that is, the amount of movement of the print head 10 can be recognized by the slit encoder 13 a and the sensor 13 b. Finally, the line feed motor 12 is a motor for driving a platen (not shown).

 The operation of the printer having the above configuration will be described.

First, when the power of the microprocessor 1 is turned on,
Read and execute the program from ROM2. By executing this program, the printer is subjected to initial processing. That is, the microprocessor 1 issues an instruction for an initial setting operation to the control circuit 4 and the drive circuit 7, checks the interface driver / receiver circuit 5, and sets the drive system 6 to a state where the printing operation can be performed at any time. This state is referred to as a drive system standby state (state in which the state flag 1a is 0).

Thus, when data is sent from a host system or the like (not shown) connected to the interface driver / receiver circuit 5, the printing operation can be immediately started.

That is, when receiving data from a host system (not shown) connected via the interface driver / receiver circuit 5, the data is stored in the RAM 3 via the control circuit 4. When the microprocessor 1 recognizes the print start control code from the data stored in the RAM 3,
A print operation command is issued to the drive circuit 7 to operate the drive system 6. This state is referred to as a drive system operating state (state in which the state flag 1a is 1). The drive system operating state is a state in which printing is being performed based on print data stored in the RAM 3.

That is, a drive signal is output from the input / output port of the microprocessor 1 to the drive circuit 7. Then, the drive circuit 7 supplies power from the power supply 8 to the space motor 11 based on the drive signal, and scans the print head 10. On the other hand, the microprocessor 1 is a slit encoder that rotates in conjunction with the space motor 11.
13a and a signal from the sensor 13b (referred to as a sensor signal), the position of the print head 10 and the space motor 11
Control of the rotation speed. At the same time, the microprocessor 1 recognizes the print timing based on the signals from the slit encoder 13a and the sensor 13b, and reads a corresponding character from the character font pattern stored in the ROM 2 based on the print data stored in the RAM 3. And the drive circuit 7
The head signal for printing is input to the print head 10 via the printer, and the data stored in the RAM 3 is sequentially printed. RAM3
When printing of one line of print data stored in
The microprocessor 1 stops outputting the drive signal to the drive circuit 7 to stop the space motor 11, and the line feed motor 12 performs a line feed for one line.

In the above-described printing operation, for example, when the drive system 6 is in the operating state, that is, when the printing operation is being performed, the space motor 11 may be damaged due to a paper jam, a malfunction of a circuit element, or a poor contact of a wiring. In some cases, an abnormal situation where rotation of the motor is stopped may occur. In this case, since the rotation of the slit encoder 13a also stops similarly to the space motor 11, the microprocessor 1 cannot detect the output signal of the sensor 13b. If this state is left unattended, heat generation of the space motor 11 and further a smoke accident will occur. For this reason, the microprocessor 1 outputs the drive signal to the drive circuit 7, that is, while the drive system is operating while the power is supplied to the space motor 11, the sensor 13
When the alarm signal 1b provided in the microprocessor 1 recognizes that the sensor signal from b has not been continuously detected for a predetermined time, the output of the drive signal is stopped. As a result, the drive circuit 7 cuts off the supply of power to the space motor 11, and the drive system 6 is forcedly put into a standby state.

(Problem to be Solved by the Invention) In the case where an abnormal situation has occurred when the drive system 6 is in the operating state as described above, the microprocessor 1 recognizes the situation and generates an accident that occurs secondarily. Was prevented.

However, the installation environment of these printers is not always good, and they may be installed in quite severe places. Further, these printers are particularly exposed to noise voltage and static electricity of an input power supply, and furthermore to temperature, humidity, vibration, and the like, and may cause malfunction of the microprocessor 1 and peripheral circuits.

Generally, once the printer is turned on, the drive system 6 is longer in the standby state than in the operation state. However, in the conventional printer, the recognition of the abnormal situation is performed only when the drive system 6 is in the operating state, and in the standby state, there is no protection against malfunction of the microprocessor 1 or circuit elements.

Therefore, if power is supplied to the drive system 6 by mistake in the standby state and an abnormal situation occurs in the drive system 6, no protection means is provided.

The present invention has been made in view of the above points, and an object of the present invention is to provide a printer in which a circuit element or the like is not damaged by an abnormal situation that occurs when a drive system is in a standby state. .

(Means for Solving the Problems) A printer according to the present invention has a drive system operating state in which a drive system having a plurality of mechanically movable parts is operated, and a drive system standby state in which the drive system is not operated. , A state flag storage means for storing a state flag by distinguishing between a drive system operation state and a drive system standby state, and a sensor connected to at least one of the mechanically movable parts for controlling the operation of the mechanically movable part It has a sensor unit for outputting a signal, and power supply control means for controlling supply of power to the mechanically movable part of the drive system.

The power supply control means, when the status flag stored in the status flag storage means indicates the drive system operation state, when the sensor output of the sensor unit stops while the mechanically movable part of the drive system is operating, Power supply to moving parts is forcibly shut off.

When the status flag stored in the status flag storage means indicates the drive system standby state, the power supply control means controls the drive system when the mechanical movable portion of the drive system is in the reception standby state and the reception processing state. The power supply to the mechanical drive portion of the drive system is forcibly and repeatedly cut off, and the supply of power to the mechanically movable portion of the drive system is forcibly cut off when the sensor output of the sensor section is generated.

(Operation) In the above-described printer, when the driving system is in the standby state, the operation of repeatedly forcibly shutting off the supply of power to the movable portion is performed. Can be avoided.

(Embodiment) FIG. 1 is a block diagram of a main part according to a printer of the present invention.

The block diagram of FIG. 1 shows in detail a portion corresponding to the microprocessor 1 and the drive system 6 of the conventional block diagram shown in FIG.

In the printer of the present invention shown in FIG. 1, a status flag recognizing means 20 and a power control means 25 are newly provided in the microprocessor 1 as compared with the conventional printer described with reference to FIG. The other parts have the same configuration as in FIG.

Now, the state flag recognizing means 20 of the processor 1 shown in FIG.
Is means for recognizing a state in which the value of the state flag 1a is 0 (drive system standby state) and operating the power supply control means 25, and is constituted by a logic circuit or the like. The power supply control unit 25 is a unit including a register for controlling the drive circuit 7 of the drive system 6 to an off state, that is, a state in which power is not supplied to the movable part 9.

The processor 1 is provided with a status flag 1a and an alarm timer 1b, similarly to the conventional printer shown in FIG.

The state flag 1a is a flag indicating the operation state and the standby state of the drive system 6. The alarm timer 1b is a counter that measures a predetermined time.

Similarly, the drive system 6 also includes a drive circuit 7, a power supply 8, and a movable part 8. The drive circuit 7 is provided with switch means 7a and a power supply 8,
A circuit for controlling power supply to the movable part 9 by turning on or off the switch 7a. The movable portion 9 is provided with a print head, a space motor, and a line feed motor (not shown), and a sensor unit 13 including a slit encoder and a sensor (not shown).

The operation of the printer having the above configuration will be described with reference to FIG.

FIG. 3 is a flowchart showing the operation of the printer of the present invention.

First, when power is turned on to the printer shown in FIG. 1, initial processing such as setting the status flag 1a to 0 is performed (step S1). Then, the state flag recognizing means 20 determines whether or not the value of the state flag 1a is 1 (step S2). If the result is NO, that is, if the drive system 6 is in the standby state, the process proceeds to step S3. In step S3, the power supply control means 25 of the microprocessor 1 is operated to forcibly set the switch means 7a of the drive circuit 7 to the off state (step S3). For this reason, power is not supplied to the movable portion 9 of the drive system 6, and the operation is not performed. Next, the process proceeds to step S4, where it is determined whether or not data has been input (information received) to the interface driver / receiver circuit 5 (FIG. 2) (step S4). If YES in step S2, the process jumps to step S4. If the result of step S4 is NO, it is determined whether an operation switch (not shown) for manually operating the drive system 6 has been turned on (step S5). If this result is NO, the process moves to step S6. In step S6, it is determined whether to start printing the data stored in RAM3 (step S6).
S6). If this result is NO, the process returns to step S2. Therefore,
When the drive system 6 is in the standby state, steps S2, S3, S4, S
The loop goes around 5, 5, and then back to step S2.

Now, if a YES result is obtained in step S4,
That is, the interface driver / receiver circuit 5 (second
If there is data input in FIG.
In step S7, a reception process for storing the data input to the interface driver / receiver circuit 5 in the RAM 3 via the control circuit 4 is performed, and then the process returns to step S2. Next, if a YES result is obtained in step S5, that is, if the operation switch is turned on, the process proceeds to step S8. Step S8
Then, the drive system 6 is controlled by the control circuit 4 corresponding to the operation switch, and after the movable portion 9 is operated, the process proceeds to step S2. When the result of TES is obtained in step S6, the process proceeds to step S9. In step S9, a drive signal is output from the microprocessor 1 to the drive circuit 7, and the switch 7a is turned on. Next, the clock of the alarm timer 1b of the microprocessor 1 is started. Then, 1 is set to the state flag 1a. As a result, the drive system 6 is set to the operating state.

According to the flow described above, the operation from the standby state to the operation state of the drive system 6 when the power of the printer is turned on is performed.

By the way, when the above-described operation is performed, a sensor signal is output from the sensor unit 13 of the movable part 9, and when the sensor signal is recognized by the microprocessor 1 via the drive circuit 7, a sensor interrupt occurs.

 FIG. 4 shows a flowchart of the sensor interruption.

Hereinafter, the flow of the flowchart described in FIG. 3 will be referred to as a main routine.

When a sensor interrupt occurs, the microprocessor 1
Determines whether the status flag 1a is 1 (step S1).
0). If the result is NO, that is, if the status flag 1a indicates the drive system standby state, the process returns to the main routine. If the result is YES, that is, if the status flag 1a indicates the driving system operation state, the process proceeds to step S11. In step S11, RA
It is determined whether the printing of the M3 data has been completed. If the result is NO, the process moves to step S12. In step S12, a printing process for printing on printing paper by the print head 10 is performed.
Move to step S13. In step S13, the alarm timer
Restart the timing of 1b and return to the main routine. If the result of step S11 is YES, that is, if the printing of the data in the RAM 3 has been completed, the process proceeds to step S14. In step S14, the timer of the alarm timer 1b is stopped and reset. Then, the drive signal from the microprocessor 1 is turned off, the switch means 7a of the drive circuit 7 is turned off, the operation of the space motor 11 is stopped, and the process returns to the main routine.

Thereafter, the same operation is repeated until the print end control code is stored in the RAM 3 and recognized by the microprocessor 1.

By the way, when the printing by the print head 10 is normally performed, the alarm timer 1b is restarted every time the sensor interrupt processing is performed, so that a predetermined time is measured, that is, the reset state is not performed. . However, the sensor interruption is performed based on a sensor signal from the sensor unit 13. For this reason, space motors
When the rotation of 11 stops, the slit encoder 13a
Does not rotate, and no sensor signal is output.

As a result, a sensor interrupt does not occur, and the alarm timer 1b measures a predetermined value, and a certain time has elapsed. When the alarm timer 1b counts a predetermined value, an alarm timer interrupt occurs.

FIG. 5 shows a flowchart of the alarm timer interrupt.

As shown in the figure, when an alarm timer interrupt occurs, the drive signal from the microprocessor 1 is turned off (step S15). As a result, the switching means 7a of the drive circuit 7 is forcibly turned off, the supply of power to the space motor 11 is stopped, and the heat generation and the smoke accident of the space motor 11 can be prevented.

Now, a case will be described in which the switch means 7a of the drive circuit 7 is turned on despite the state flag 1a being 0 for some reason.

This state indicates an abnormal situation in which the drive system 6 is in the standby state according to the state flag 1a, but is actually in the operating state.

In this case, as shown in FIG. 3, it is determined whether or not the status flag 1a is 1 in step S2. In this case, since the result is NO, step S3 is executed. In step S3, as described above, the power supply to the space motor 11 is cut off in order to forcibly turn off the switch means 7a of the drive circuit 7, whereby the drive system according to the state flag 1a is turned off. Although the driving system 6 should be in the standby state, when the driving system 6 is actually operating, the operating state of the driving system 6 can be quickly released as indicated by the status flag 1a.

As described with reference to FIG. 3, the processing for forcibly turning off the switch means 7a of the drive circuit 7 (step S3) is as follows.
It is performed once each time the loop of steps S2, S3, S4, S5, S6, and S2 is performed, and thus is repeated as long as the status flag 1a indicates the standby state of the drive system 6.

 The printer of the present invention is not limited to the above embodiment.

FIG. 6 shows a flowchart of another embodiment according to the present invention.

Normally, the printer is provided with a drive timer for setting the drive time of the space motor 11 of the movable part 9 and the line feed motor 12 in addition to the alarm timer 1 b provided in the microprocessor 1. When the processing of the main routine shown in FIG. 3 has been performed, this driving timer interrupt is generated, and processing for restarting the driving timer is performed.

When the drive timer interrupt occurs, the microprocessor 1 determines whether or not the drive system 6 is operating (step S20). If a NO result is obtained in step S20, the process proceeds to step S21. In step S21, the switch 7a of the drive circuit 7 is turned off, the supply of power to the movable part 9 is cut off, and the process proceeds to step S22. In step S22, the driving timer is restarted and the process returns to the main routine. Steps
When a result of YES is obtained in S20, the process proceeds to step S23.
In step S23, the movable part 9 is
Power is supplied, normal operation is performed, and the routine goes to Step S22.

As described above, each time power is supplied from the drive circuit 7 to the movable portion 9, it is determined whether or not the drive system 6 is in an operating state, whereby an abnormal situation can be avoided.

The medium for forcibly shutting off the power is a space motor.
Not only 11 but also the entire movable part 9 and the microprocessor 1
It can also be used for parts where it is not necessary to operate without control.

(Effects of the Invention) The printer according to the present invention having the above-described structure can be repeatedly mechanically operated even when the drive system is operated by mistake while the printer is in the reception standby state or the drive system standby state during reception processing. In order to cut off the power supply to the movable parts, not only against failures that occur when the drive system is in the operating state, but also in any case, heat generated by mechanical failures due to failures and damage to circuit elements etc. Can be prevented beforehand.
Therefore, even if the drive system malfunctions in the standby state when the device is installed under severe environmental conditions including noise voltage and static electricity of the input power supply, and furthermore, temperature, humidity, vibration, etc., the power supply to the drive system can be reliably shut off. Therefore, a highly secure printer can be provided. Even when the printer is performing reception processing, since the power supply to the drive system is repeatedly cut off, even if the printer has a large reception memory capacity and spends a considerable amount of time in the reception processing, the drive system cannot be used. Malfunction can be reliably stopped. That is, it is possible to provide a printer in which power is not supplied to a mechanically movable portion due to a malfunction even when the printer is in any state, and heat generated in the mechanically movable portion and circuit elements are not damaged.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a printer according to the present invention.
FIG. 3 is a block diagram of a conventional printer, FIG. 3 is a flowchart showing the operation of the printer of the present invention, FIG. 4 is a flowchart of a sensor interrupt of the printer of the present invention, and FIG. 5 is an alarm timer of the present invention. FIG. 6 is a flowchart showing the operation of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Microprocessor, 1a ... State flag, 1b ... Alarm timer, 6 ... Drive system, 7 ... Drive circuit, 7a ... Switch means, 8 ... Power supply, 20 ... State flag recognition means, 25 ... Power supply control means.

Claims (1)

(57) [Claims] 1. A printer having a driving system operating state in which a driving system having a plurality of mechanically movable parts is operated, and a driving system standby state in which the driving system is not operated, wherein the driving system operating state and the driving system State flag storage means for storing a state flag in distinction from the drive system standby state; a sensor connected to at least one of the mechanically movable parts and outputting a sensor signal for controlling the operation of the mechanically movable part And a power control means for controlling the supply of power to the mechanically movable part of the drive system, wherein the power control means is configured so that the status flag stored in the status flag storage means is the drive system operating state. When the sensor output of the sensor unit is stopped while the mechanically movable part of the drive system is operating, the supply of power to the mechanically movable part of the drive system is forcibly cut off, When the status flag stored in the flag storage means indicates the drive system standby state, the mechanical movable portion of the drive system is in the reception standby state and the reception processing state where the mechanical movable portion of the drive system is stopped. A power supply to the mechanically movable portion of the drive system is forcibly cut off when a sensor output of the sensor section is generated.