JPS6041397B2 - Electronic desk calculator with printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic desktop calculator with a printing device that warns when the drive motor of the printing device is locked due to printing vapor getting caught or the like.

2. Description of the Related Art Conventionally, as a drive circuit for a printing device of an electronic desk calculator equipped with a printing device, a circuit as shown in FIG. 1, for example, has been known. That is, the drive circuit of the printing device shown in FIG. 1 consists of transistors Tr,..., Tr4 and resistor R.
,,..., A drive signal input circuit 2 consisting of a capacitor C, a diode D and a resistor R5 is connected to the input side of the switch circuit 1 consisting of R4, and the signal is input to the input terminal 3 from the circuit body of an electronic desk calculator (not shown). The motor drive signal is /
・When the level is reached, the capacitor C is charged, and the above-mentioned state is maintained only while the potential at the connection point 4 between the resistors R and R2 becomes higher than the base-to-emitter voltage VBE of the transistor Tr. By turning on the transistor Tr, the transistor Tr2 is turned off, and by turning off the transistor Tr2, the transistors Tr3 and Tr4 are turned on and off, respectively, and the ground line 6 of the printing device 5 is connected to the ground line 7. Printing vapor (not shown)

) Even if the drive motor 8 of the printing device 5 is locked due to jamming, etc., after the capacitor C has been charged,
The ground line 6 of the printing device 5 is connected to the ground line 7.
In order to prevent current from continuing to flow to the drive motor 8 of the printing device 5 and the printing solenoids 9, 9, etc., the gear section (not shown) of the drive motor 8 is put under stress and breaks down. This is to prevent the drive motor 8 and printing solenoids 9, 9, . . . from burning out. However, the drive circuit of the printing device as shown in FIG. 1 does not have a function to notify the operator that the drive motor 8 of the printing device 5 is locked. There is a risk that the key operation may be continued even after locking without being able to do so, and in such a case, a mechanically powerless force will remain applied to the gear section of the drive motor 8, causing the upper gear section to There was a problem with damage. In FIG. 1, Tr5, . . . print signals input from the circuit body of the electronic desk calculator via input terminals 10, . . . and resistors R6, .
This is a transistor that turns on and off the current of the printing solenoids 9, 9, . . . . The present invention was made to eliminate the above-mentioned problem in conventional electronic desktop calculators with printing devices, and the gear portion of the drive motor may be damaged if key operations are performed while the drive motor is locked. The purpose is to provide an electronic desktop calculator with a printing device that is easy to use.

An electronic desktop calculator equipped with a display device for displaying calculation results and a printing device for recording the display contents of the display device, which controls the display device and printing device and performs calculations. It is set and reset by the drive signal and drive stop signal of the printing device output from the circuit body, and has a set time that is at least longer than the time from the start of printing to the end of printing, and after the above setting, the printing device operates. A timer interrupt circuit consisting of a timer that counts time independently from the printer is provided, and a switch circuit is also provided to turn on and off the power supply to the printing device. When the drive motor is locked and the timer times out, a timer interrupt signal output from the timer interrupt circuit causes the circuit main body to output a drive stop signal for the printing device to the switch circuit, and then to the printing device. 1. An electronic desktop calculator with a printing device, characterized in that the power supply is turned off and a mode lock display signal or a mode lock signal is output.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 2, 1 is a switch circuit, and 5 is a printing device, which have exactly the same configuration as in FIG. 1.

On the other hand, 11 is a large scale integrated circuit (LSI) circuit of an electronic desk calculator, and 12 is a segment signal S, ..., S and a grid signal C. , . . . , Gm, and 13 is an alarm device that performs an alarm operation in response to an alarm signal W output from the circuit main body 11.

The circuit body 11 is provided with a timer which is set and reset by the rise and fall of the drive signal MD output to the switch circuit 1, and which has a set time that is at least longer than the time from the start of printing to the end of printing. and a timer interrupt section 1 that outputs a timer interrupt signal TI when the timer times up.
There are 4.

In addition to the arithmetic function, the circuit main body 11 also has the timer trough.

The drive signal MD of the printing device 5, which receives the timer interrupt signal TI from the switch circuit 14 and outputs it to the switch circuit 1, is set to L.
On the other hand, if the display tube 12 as a display device has a character display function, the drive motor 8 of the printing device 5
Segment signals S, . . . , S and grid signals G, .
It has a function of outputting an alarm signal W. Furthermore, as shown in FIG. 2, the circuit main body 11 receives print signals PT,...
..., PTn are input to the transistors Tr5, ... of the printing device 5, and according to the printing signals PT, ..., PTn, the current of a predetermined printing solenoid 9 is turned on, and the current of the other solenoids 9, ... is turned on. The printing digit is output from the drive motor 8 of the printing device 5 when printing of the predetermined digit is completed and the next digit can be printed. By inputting the timing signal T, the print signal PT, . . . , PTn of the next digit is output. Next, the operation of the circuit shown in FIG. 2 will be explained with reference to the flowchart shown in FIG.

As shown in FIG. 3, the circuit body 11 of the electronic desktop calculator
When entering the printing routine (starting printing), the drive motor 8
The drive signal C is set to H level (MD set).

When the drive signal MD becomes H level, the timer interrupt section 14 is set, and the transistors Tr and T are turned on and off, respectively, so that the transistor Tr3 is turned on and the transistor Tr4 is turned off.

By turning on and off the transistors Tr3 and Tr4, the ground line 6 of the printing device 6, which had been short-circuited to the power supply line 15, is connected to the ground line 7, and the voltage Vp of the power supply line 15 is applied to the drive motor 8. be done.

Therefore, the drive motor 8 starts rotating and outputs the print digit timing signal T to the circuit body 11.

The circuit main body 11 judges whether the input printing timing signal T is T=1 or not, and outputs the printing signals PT,..., PTn when T=1, and outputs the printing signals PT,..., PTn to the printing device. 5
prints the character in the Nth digit.

Thereafter, in the same manner, the circuit main body 11 judges whether T=1 or not, and sequentially sends (N-1) to the printing device 5.
Digits, (N-2) digits, etc. are printed, and when the printing of the first digit is completed, the circuit main body 11 sets the motor drive signal MD to L level (MD reset) and resets the timer.
The reset section 14 is reset. As described above, when the motor drive signal MD becomes L level, the transistors Tr and Tr2 are turned off and on, respectively, and the transistors Tr3 and Tr4 are turned off and on, respectively.

Therefore, the voltage between the ground line 6 and the power supply line 15 becomes zero, and the printing device 5 stops (EP character ends).

When the printing device 5 is free from printing vapor or the like and the drive motor 8 is not locked and operates normally, the above series of operations is a timer rough. The timer interrupt unit 14 is reset before outputting the timer interrupt signal TI, but during the printing operation of the printing device 5, the drive mode is When the print timing signal T is locked, the print timing signal T is not generated from the drive motor 8, and the judgment as to whether T=1 is repeated for a certain print digit, for example, the N-1 digit, and the print control program cannot proceed. . If the above condition continues, the timer interrupt section 14
The count of the timer advances, and at the end of the count, the timer interrupt section 14 outputs the timer interrupt signal TI (timer interrupt).

By the timer interrupt signal TI, the circuit main body 11
sets the motor drive signal MD to L level (MDIJ-bit) to cut off the power to the printing device 5 to prevent damage to the drive motor 8.
At the same time, the bell constituting the alarm device 13 is dimmed (
After the bell is turned on to notify the operator that the drive motor 8 is locked, the printing operation is temporarily stopped (stopped).

Next, in the embodiment shown in FIG. 4, the circuit main body 11 of the electronic desktop calculator does not have the function of the timer interrupt section 14. A timer 17 is provided outside the circuit main body 11, and is set by the rise of the motor drive signal MD and reset by the fall of the motor drive signal MD by the inverter 6. In this case, the circuit shown in FIG. 2 can perform exactly the same operation as the circuit shown in FIG. Note that the present invention is not limited to the above-mentioned embodiments, and can be applied to devices that use a printing device in addition to electronic desktop calculators.
For example, it can be applied to cash registers, etc.
Further, it is also possible to use another display device in addition to the character display tube 12 to display the lock using a symbol such as a slash, for example.

As is clear from the above detailed explanation, the present invention provides a timer trough that is output when the drive motor of a printing device is locked due to printing vapor getting caught or the like. In addition to stopping the printing device in response to a signal, the operator is notified of the locking of the drive motor using a display or warning device. ■Stopping the printing device may cause burnout of the drive motor or printing solenoid, or damage to the drive motor's gear. ■Since the operator is notified that the printing device 5 is locked, the cause of the lock can be quickly removed, and even if the printing device 5 is locked, By providing a timer interrupt function in the circuit body of an electronic desktop calculator, you can prevent erroneous operations such as repeated key operations. The cost is almost the same as that of a desktop calculator, and the effects are very large.

[Brief explanation of the drawing]

FIG. 1 is a drive circuit diagram of a conventional printing device, FIG. 2 is a drive circuit diagram of a printing device of an electronic desktop calculator according to the present invention, and FIG.
The figure is a flowchart showing the operation of Figure 2, and Figure 4 is a flowchart showing the operation of Figure 2.
It is a circuit diagram of a modification of the figure. DESCRIPTION OF SYMBOLS 1... Switch circuit, 5... Printing device, 8... Drive motor, 9... Printing solenoid, 11... Circuit body,
12. ．． ．． Display tube, 13... Alarm, 14... Timer interrupt section. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An electronic desktop calculator that is equipped with a display device that displays calculation results and a printing device that records the display contents of the display device, which controls the display device and printing device and also performs calculations. It is set and reset by the drive signal and drive stop signal of the printing device outputted from the circuit body of the circuit, and has a setting time that is at least longer than the time from the start of printing to the end of printing, and after the above setting, printing is stopped. A timer interrupt circuit consisting of a timer that counts time independently of the operation of the device is provided, and a switch circuit is provided to turn on and off the power supply to the printing device, and the printing device is driven by the capture of printing paper, etc. When the motor is locked and the timer times up, the timer interrupt signal output from the timer interrupt circuit causes the circuit main body to output a drive stop signal for the printing device to the switch circuit, thereby supplying power to the printing device. An electronic desk calculator with a printing device, characterized in that it outputs a motor lock display signal or a motor lock alarm signal when the motor lock is turned off.