JPS6056638B2 - Electronic equipment with printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a battery-powered electronic device with a printer that can prevent CPU malfunctions and loss of calculation contents caused by printer operation.

Conventionally, in electronic desktop calculators equipped with printers,
When the battery voltage of the power supply drops below a certain level, an alarm lamp is lit to notify the user of the abnormality in the power supply voltage.

However, in the conventional method described above, since it is not known when the alarm lamp will turn on, the user's detection of abnormal conditions is delayed, and the battery voltage drops excessively due to the power consumption of the motor etc. during printer operation, which results in the internal computer The CPU itself malfunctioned, and the contents that were in the middle of calculation were erased.
Operators sometimes felt inconvenienced. The present invention solves the above-mentioned conventional drawbacks, and aims to provide a printer-type electronic device that can prevent malfunctions of the CPU and disappearance of calculation contents due to the drive of the printer.

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

FIG. 1 is a block circuit diagram of essential parts of an electronic device with a printer according to the present invention.

In the figure, a voltage generated in a battery 1 is converted to a constant reference voltage by a reference voltage generator 2, and the reference voltage and the voltage of the battery 1 are compared by a voltage comparison circuit 3. The operation of this voltage comparison circuit section 3 is performed as follows. That is, when performing a printing operation, a signal for voltage comparison is output from the control section 4 that generates the detection timing before the printer's motor drive signal turns ON, and based on this signal, the voltage comparison circuit section 3 compares the battery voltage with the reference. The voltage is compared with the voltage, and the resulting detection signal is output to the print operation permission control section 5. Next, the print operation enable/disable controller 5 receives a signal from the voltage comparator circuit, and if it receives a signal indicating that the battery voltage has fallen below a certain predetermined value, the print operation is not performed, and the state of the computer is Return to display state. Further, if the signal indicates that the battery voltage is higher than a certain predetermined value, the drive unit driver 6 operates the printer drive unit 7 to turn on the print control operation. The above is a general description of the power supply circuit section, but a more detailed description will be given next. FIG. 2 is a circuit diagram of the reference voltage generating section 2 shown in FIG. 1.

As shown in the figure, by using the voltage between the source S and the gate G via the FET 8 and setting the resistors Rl and R2 to appropriate values, it is possible to extremely reduce the reactive current.
A good regulator whose output voltage hardly changes depending on the battery voltage can be constructed. Note that it may be configured with various other regulators. FIG. 3 is a circuit diagram showing the voltage comparison circuit 3.

In the figure, when the voltage comparison circuit 3 receives a signal B for battery voltage comparison from the control unit 4, the transistor Trl
becomes 0N. Here, the base potential of the transistor Tr2 is +e, where the battery voltage is the saturation voltage of the E1 transistor TrlE-e.
R3+R4ru.

Then, the print operation enable/disable control signal level A is “°H”.
The value of ■BO of transistor Tr2 that becomes ``゛a゛,
When the reference voltage is ■, the battery voltage has decreased to E-E V-a≧-R4+e R3+R
At 4, the calculator is returned from the print state to the calculation and display state, which is the standby state of the calculator, and if the conditions of E-a ■-a-a-dama, +e are satisfied, then the printer is pressed R3.
+R4 This turns the linter motor ON and performs printer control operations.

Time charts of the above operations are shown in FIGS. 4 and 5, where FIG. 4 shows the case where the battery voltage is below a predetermined value, and FIG. 5 shows the case where the battery voltage is above the predetermined value.

Here, C indicates the print routine time, D indicates the motor control signal, and E indicates the motor ON time. Further, FIG. 6 shows a flowchart for controlling battery voltage comparison timing and printer operation control after battery voltage comparison. As shown in Figure 6, in the standby state, a normal calculator is in the display routine for a display type calculator, or in the key reading routine for a printer-only calculator, and is reprinted by operating the print key from the calculation and display routine 9. The process proceeds to the print routine 11 via the determination 10.

As shown in the figure, in the present invention, when printing is instructed, a signal for battery voltage comparison 12 is output, and the battery voltage comparison circuit operates. If the battery voltage is equal to or higher than a predetermined value (H), the printer motor is turned ON13, and printer control operation 14 is performed. Also, the battery voltage is below the specified value (
If the result is L), the circuit is configured to return to the calculation and display routine 9. Further, as shown in FIG. 7, if there is no problem with the battery voltage, a motor control signal is output from the print operation permission control section 5, and the motor 15 of the printer is driven.

In the above explanation, the voltage alarm for the CPU was not mentioned, but the CPU alarm uses a conventional system and has no effect.

That is, since the alarm point of the CPU is considerably lower than the alarm voltage of the printer, the contents of the CPU can be sufficiently guaranteed if the printer's operation is skipped even at the time of the alarm. As explained above, when a print command is issued, the electronic device with a printer of the present invention performs a battery check, and if the voltage value is sufficient to drive the printer, it immediately drives the printer, and if the voltage value is low, it performs calculations and Alternatively, since only the display is driven, it is possible to avoid driving the printer with a voltage value that is inappropriate for the printer, so the operation of the printer, which consumes a lot of power, is appropriately controlled, reducing power consumption, and printing. The occurrence of malfunctions can be prevented. Furthermore, by omitting the printer operation and performing other functions, it is possible to eliminate the cause of malfunctions of the CPU, etc. caused by the printer.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of the main parts of an electronic device with a printer according to the present invention, Fig. 2 is a circuit diagram of a reference voltage generating section, Fig. 3 is a circuit diagram of a voltage comparison circuit, and Figs. 4 and 5 are FIG. 6 shows a time chart of each part of the circuit, a flowchart is shown in FIG. 6, and FIG. 7 shows a circuit diagram of the printer operation section. In the figure, 1: battery, 2: reference voltage generation section, 3: voltage comparison circuit section, 4: detection timing control section, 5: print operation availability control section, 6: drive section driver, 7: printer drive section.

Claims (1)

[Claims] 1. In an electronic device with a printer that uses a battery as a driving power source and has an arithmetic function, there is a reference voltage generation section that generates a constant reference voltage, and a control section that generates a detection timing signal before the printer drive signal is turned on. , a voltage comparison circuit that compares the battery voltage and the reference voltage in response to the detection timing signal and outputs the comparison result; and a voltage comparison circuit that drives the printer if the battery voltage is equal to or higher than a predetermined value as a result of the comparison. and a drive control unit that only drives the calculation or calculation and display of the device regardless of a print instruction if the value is below a predetermined value.