JPH06233465A - Electronic device - Google Patents

Abstract

PURPOSE:To make it possible to detect faulty drive of an external device always with a proper allowable voltage of main unit of the device even though an external device is replaced in an electronic device to which the external device can be removably connected to the main body of the device. CONSTITUTION:Respective external devices 21 and 24 have built-in type signal output means 32 which output a voltage drop signal to the main body 20 of the device when the drive voltage supplied from the main body 20 of the device drops below the preset allowable voltage; and fault detecting means 27, which can detect faulty drive of the external devices 21 and 24 after receiving a voltage drop signal, is built in the main body 20 of the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device such as an electronic cash register.

[0002]

2. Description of the Related Art Electronic equipment such as an electronic cash register is used, for example, in AC / DC (Alternating Current / Direct).
Current) A power supply unit such as a converter is built into the main body of the device, and the I / O (Input / Outp
ut) display and R / J / S (Receipt / Jour)
nal / Slip) It has a structure in which an external device such as a printer is connected. In such an electronic device, the power supply unit of the apparatus main body supplies the drive voltage to the external device from the I / O port, so that these external devices can operate without incorporating the power supply unit. .

Therefore, a first conventional example of such an electronic device will be described with reference to FIGS. 4 and 5. First, as shown in FIG. 4, an electronic cash register 1 which is this electronic device has an I / I which is an n number of connection parts of one device main body 2.
The O port 3 has a structure in which n external devices 4 such as displays and R / J / S printers are individually connected.

The device body 2 of the electronic cash register 1 has a power supply circuit 6 which is a power supply unit connected to a commercial power supply 5, and a power failure detection for detecting an abnormal decrease in drive voltage output from the power supply circuit 6. Circuit 7 and CPU (Central
A control circuit 8 including a processing unit) is built in and connected to each other, and the control circuit 8 and the power supply circuit 6 are both connected to each of the I / O ports 3. Further, the power failure detection circuit 7 of the device body 2 is
As illustrated in FIG. 5, the Zener diode 9 and the inverter 10 whose breakdown voltage is the allowable voltage are connected in series, and when the supplied drive voltage becomes lower than the breakdown voltage of the Zener diode 9, the inverter 10
The voltage drop signal, which is the error information output by, changes from "L" to "H".

In such a structure, in the electronic cash register 1, the control circuit 8 of the apparatus main body 2 outputs various signals to each of the external apparatuses 4 to be driven and I / O.
By supplying the drive voltage from the power supply circuit 6 from the port 3,
An external device 4 such as a display or an R / J / S printer which does not have a power supply unit is operated.

In the electronic cash register 1, for example, when the driving voltage output from the power supply circuit 6 is lowered due to the voltage drop of the commercial power supply 5, the breakdown of the Zener diode 9 is caused in the power failure detection circuit 7. The voltage may drop below a preset allowable voltage. Then,
Since the voltage drop signal output from the power failure detection circuit 7 changes from "L" to "H", the control circuit 8 that receives this voltage drop signal detects a drive failure of the external device 4, and, for example,
The user is notified of the error occurrence by blinking a pilot lamp (not shown) or the like, and the driving of the external device 4 is stopped.

Here, in the electronic cash register 1, the allowable voltage that can be detected by the power failure detection circuit 7 is one type set by the breakdown voltage of one Zener diode 9, and a plurality of external devices 4 having different drive voltages. It is not possible to set the allowable voltage of the power failure detection circuit 7 corresponding to each of the above, but the allowable voltage is set corresponding to the external device 4 having the highest operable drive voltage. However, in this case, even if the external device 4 such as an R / J / S printer having a high driving voltage cannot operate and the external device 4 having a low driving voltage such as a display can operate, the control circuit 8 controls the external device 4 to operate. Since the drive failure is uniformly detected and the drive of all the external devices 4 is stopped, the utilization efficiency of the external devices 4 is deteriorated and the work efficiency of the electronic cash register 1 is reduced.

Therefore, an electronic cash register that solves such a problem is shown in FIG. 6 as a second conventional example of an electronic device.
And it demonstrates below based on FIG. Here, the same parts as those of the electronic cash register 1 described as the first conventional example have the same names and reference numerals, and detailed description thereof will be omitted. First, as shown in FIG. 6, the electronic cash register 11 which is this electronic device individually connects n external devices 4 to the I / O ports 3 which are the n connecting portions of one device main body 12. The apparatus main body 12 has a built-in power supply circuit 6, a power failure detection circuit 13, a control circuit 14, and the like.

Here, as shown in FIG. 7, the power failure detection circuit 7 of the apparatus main body 12 includes a Zener diode 9 and an inverter 10 connected in series, a Zener diode 15 _{1 to} 15 n, and a switching transistor 1.
6, 17 has a structure in which a plurality of voltage setting devices 18 ₁ to 18 n are sequentially connected in parallel. Here, the breakdown voltage of the Zener diode 9 sets the allowable voltage of the control circuit 14, and the Zener diode Diode 15 ₁ to 1
Allowable voltage of the n external device 4 ₁ to 4n in the breakdown voltage of 5n are set individually.

The electronic cash register 11
Then, the control circuit 14 of the apparatus body 12 sends I / O control signals together with various information to the plurality of I / O ports 3.
It is designed to output individually to _{1 to} 3n.
/ O control signals are outputted individually to a plurality of said voltage setter 18 ₁ ~18n of the switching transistor 17 of the power failure detection circuit 13.

[0011] In such a configuration, in the electronic cash register 11, device when the main body 12 is driven a predetermined external device 4 ₁ to 4n, the control circuit 14 I / O ports of the external device 4 is connected to drive 3 also outputs the I / O control signal to a predetermined voltage setter 18 ₁ ~18n power failure detection circuit 13 outputs an I / O control signals. Then, the voltage setter 18 sets a permissible voltage corresponding to a predetermined external device 4 in the power failure detection circuit 13, and in this state, the drive voltage of the power supply circuit 6 fails due to the voltage drop of the commercial power supply 5 or the like. When the voltage drops below the allowable voltage of the detection circuit 13, the voltage drop signal of the power failure detection circuit 13 changes from "L" to "H", so that the control circuit 14 detects the drive failure of the external device 4.

By doing so, in the electronic cash register 11, the allowable voltage that can be detected by the power failure detection circuit 13 is divided into a plurality of stages by the breakdown voltage of the Zener diodes 15 _{1 to} 15n of the plurality of voltage setters 18 _{1 to} 18n. Since it is set to be switchable, the allowable voltage of the power failure detection circuit 13 can be set individually corresponding to the plurality of external devices 4 having different drive voltages. Therefore, in this electronic cash register 11, for example, R / J / with a high drive voltage is used.
When the external device 4 such as the S printer cannot operate and the external device 4 having a low drive voltage such as the display can operate, the control circuit 14 can stop driving only the external device 4 that cannot drive. Therefore, the utilization efficiency of the external device 4 can be improved.

[0013]

THE INVENTION Problems to be Solved] In the electronic cash register 11, the plurality of external devices 4 ₁ failure detection circuit of the allowable voltage corresponding to each ~4n an apparatus main body 12 13
Therefore, when the drive voltage is lowered, it is possible to stop the drive of only the external device 4 that cannot be driven by the device main body 12.

Here, in the electronic cash register 11 as described above, the external device 4 connected to the device body 12, such as an R / J / S printer and a display, should be replaced with a model different depending on the customer's request and specifications. But there is
For example, the drive voltage is greatly different between a display composed of a CRT (Cathode Ray Tube) and a display composed of an LCD (Liquid Crystal Display). In the electronic cash register 11 described above, the allowable voltages corresponding to each of the plurality of external devices 4 _{1 to} 4 n are set, but these allowable voltages are set to the plurality of I / O ports 3 _{1 to} 3 n.
This is fixed for each I / O port 3
_When the drive voltage of the external devices 4 _{1 to} 4 n individually connected to _{1 to 3} n changes, the allowable voltage cannot be changed correspondingly.

Therefore, in the electronic device such as the electronic cash register 11 described above, when a plurality of types of external devices 4 having different drive voltages are exchangeably connected to the I / O port 3 of the device main body 12, the external device 4 is exchangeable. It is extremely difficult to properly set the allowable voltage.

[0016]

At least one connecting portion to which one of a plurality of types of external devices having different driving voltages is exchangeably mounted is formed in the main body of the device, and the driving voltage is applied from the connecting portion to the external device. In an electronic device in which a power supply unit for supplying the power source is built in the device body, the signal output means for outputting a voltage drop signal to the device body when the drive voltage supplied from the device body drops below a preset allowable voltage is provided. Defect detection means, which is individually built in the external device and detects a drive defect of the external device when a voltage drop signal is received from the external device, is built in the device body.

[0017]

The signal output means individually incorporated in the external device outputs a voltage drop signal to the device main body when the drive voltage supplied from the connection portion falls below the preset allowable voltage. The defect detecting means detects a drive defect of the external device when receiving the voltage drop signal from the external device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. Here, the same parts as those of the electronic cash registers 1 and 11 illustrated as the first and second conventional examples are denoted by the same names and reference numerals, and detailed description thereof will be omitted.

First, as shown in FIG. 2, the electronic cash register 19 which is an electronic device has a flat box-shaped device body 20 loaded on a drawer 21 which is an external device having substantially the same shape. On the device body 20, the keyboard 22 and the R / J / S printer 2 which are external devices are provided.
3 and the CRT display 24 are arranged. Further, the electronic cash register 19, as the circuit manner illustrated in FIG. 1, the drawer 21 and Ya the keyboard 22 into n is a connection unit I / O port 25 ₁ ～25N of the apparatus main body 20 It has a structure in which n external devices such as the R / J / S printer 23 and the CRT display 24 are individually connected.

The electronic cash register 19
The device main body 20 is a power supply circuit 6 that is a power supply unit connected to the commercial power supply 5, a power failure detection circuit 26 that detects an abnormal decrease in the drive voltage output by the power supply circuit 6, and a control that is a failure detection means. The circuit 27 is built in and connected to each other. Here, the power supply circuit 6, the power failure detection circuit 26, and the control circuit 27 are connected to each of the I / O ports 25.

Here, this electronic cash register 19
The control circuit 27 and the power supply circuit 6 are connected to the drawer 21 and the CRT display 24, which are external devices of the above, through various I / O ports 25 to various built-in driving units 28 and 29. ing. Further, the drawer 21
In the CRT display 24 and the like, the signal output devices 32 _{1 to} 32 n, which are signal output means having a structure in which Zener diodes 30 _{1 to} 30 n and an inverter 31 are connected in series.
The input terminals and output terminals of the signal output devices 32 _{1 to} 32 n are respectively connected to the power supply circuit and the power failure detection circuit 26 via the I / O port 25.

On the other hand, in the power failure detection circuit 26 of the apparatus body 20 of the electronic cash register 19, as shown in FIGS. 1 and 3, the Zener diode 9 connected to the power supply circuit 6 via the inverter 10. OR gate 3
3 is connected to one of the input terminals of the OR gate 33, and the other input terminal of the OR gate 33 is connected to the signal output devices 32 _{1 to} 32 n of the drawer 21 and the CRT display 24 via the I / O port 25. Are connected. The OR gate 33 of the power failure detection circuit 26 is connected to the control circuit 27, and the control circuit 27 is connected to the I gate.
Signal output devices 32 _{1 to} 32 n such as the drawer 21 and the CRT display 24 are connected via the / O port 25 and the power failure detection circuit 26.

Therefore, this electronic cash register 19
Then, the allowable voltage of the control circuit 27 is set by the breakdown voltage of the Zener diode 9 in the power failure detection circuit 26 built in the apparatus body 20, and the drawer 21 is
And the Zener diode 30 _{1 of the} signal output devices 32 _{1 to} 32 n built in the CRT display 24 or the like.
The allowable voltage of the drawer 21, the CRT display 24, etc. is individually set at a breakdown voltage of ˜30 n.

The electronic cash register 19
Then, the drive voltage supplied from the I / O port 25 of the apparatus body 20 to the drawer 21, the CRT display 24, etc. is the breakdown voltage of the Zener diodes 30 _{1 to} 30 n of the signal output devices 32 _{1 to} 32 n. When the voltage drops below a certain allowable voltage, the signal output devices 32 _{1 to} 32 n output a voltage drop signal that changes from “L” to “H” to the I / O.
It will be output to the port 25.

Therefore, the power failure detection circuit 26 that has received the voltage drop signal from the predetermined I / O port 25 outputs the voltage drop signal to the control circuit 27 from the OR gate 33 and directly transmits it. The control circuit 27 detects a drive failure of the drawer 21, the CRT display 24, and the like, and also identifies the drawer 21, the CRT display 24, and the like in which the drive failure has occurred.

In such a configuration, when the electronic cash register 19 is used to perform a sales operation, when the clerk operates the keyboard 22 to input the identification information of the product that the customer desires to purchase, the identification is performed. In accordance with the information, the control circuit 27 of the apparatus main body 20 executes the registration process, and various information is output by printing on the R / J / S printer 23 or displaying on the CRT display 24. Therefore, when the above-described registration processing is completed for all products, the clerk and the customer visually check the total amount of money displayed on the CRT display 24 of the electronic cash register 19 and use the cash or the like in the drawer 21. Accounting will be performed.

The electronic cash register 19
Then, when executing the sales work as described above, the control circuit 27 outputs various information to the predetermined I / O port 25 of the apparatus main body 20 and the power supply circuit 6 outputs the driving power, This drive power and various information are transferred to the I / O port 2
Drawer 21 and CRT display 24 input from 5
Etc. are designed to be driven. At this time, commercial power supply 5
When the driving voltage supplied from the power supply circuit 6 of the main body 20 in the drawer 21 and CRT display 24 or the like becomes lower than the allowable voltage of the signal output unit 32 ₁ ～32N for voltage drop or the like, the signal output device 32 ₁ 32n is a voltage drop signal that changes from “L” to “H”, which is I / O of the device body 20.
Since the voltage drop signal is returned to the port 25, the voltage drop signal is input from the predetermined I / O port 25 to the power failure detection circuit 26, passes through the OR gate 33, and directly controls the control circuit 2.
7 is output.

Then, the control circuit 27 detects the drive failure of the drawer 21, the CRT display 24, etc., by the voltage drop signal received from the OR gate 33, and the voltage drop received directly from the predetermined I / O port 25. Drawer 21 or CRT display 2 where drive failure occurred due to signal
Specify 4 etc. Therefore, the control circuit 27, for example, blinks a pilot lamp (not shown), displays a guidance on the CRT display 24, prints a message on the R / J / S printer 23, or the like, so that a predetermined external device is not driven properly. The user will be notified of the occurrence.

Then, this electronic cash register 19
Since the allowable voltage of the drawer 21, the CRT display 24 and the like is set by the Zener diode 30 incorporated therein, the device body 20 does not need to manage the allowable voltage of the drawer 21, the CRT display 24 and the like. Therefore, in the electronic cash register 19, for example, when the R / J / S printer 23 having a high driving voltage cannot operate and the drawer 21 having a low driving voltage can operate, the control circuit 27 of the apparatus body 20 drives. Since the drive of the impossible R / J / S printer 23 and the like can be stopped and the drawer 21 and the like can continue to be driven, the utilization efficiency of the external device is good and it is possible to contribute to the improvement of the work efficiency.

Furthermore, this electronic cash register 19
Then, the R / J / S printer 23 connected to the apparatus main body 20
Depending on the customer's request and specifications, for example, a CRT display 24 having a high driving voltage may be used.
May be replaced with an LCD display (not shown) with a low drive voltage. In such a case, in the electronic cash register 19, since the allowable voltage is set in the Zener diode built in the LCD display to be replaced in advance, even if such an external device is replaced, the device main body 20 is always kept proper. It is possible to detect an abnormal decrease in the drive voltage with various allowable voltages.

In the present embodiment, the electronic cash register 19 is illustrated as an electronic device for connecting an external device to the device body in a replaceable manner, but the present invention is not limited to the above embodiment, and a personal computer or a work is used. The present invention can be applied to various electronic devices such as stations (both not shown).

Further, in the electronic cash register 19 of the present embodiment, the signal output device 32, which is a signal output means for outputting a voltage drop signal when the drive voltage becomes lower than the preset allowable voltage, is provided with the zener diode 30 and the inverter 3.
However, the present invention is not limited to the above embodiment, and for example, an electronic device (not shown) in which the signal output means is formed by a one-chip CPU can be implemented. .

[0033]

As described above, according to the present invention, the signal output means for outputting the voltage drop signal to the device body when the drive voltage supplied from the device body falls below the preset allowable voltage is individually incorporated in the external device. However, since the failure detection means for detecting a drive failure of the external device when the voltage drop signal is received from the external device is incorporated in the device body, the allowable voltage is individually set in advance in the external device. Even if the device is replaced, the defect detecting means of the device main body has an effect that it can always detect the drive defect with an appropriate allowable voltage.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit structure of an electronic cash register which is an embodiment of an electronic device of the invention.

FIG. 2 is a perspective view showing an appearance of an electronic cash register.

FIG. 3 is a circuit diagram showing a power failure detection circuit.

FIG. 4 is a block diagram showing a circuit structure of an electronic cash register which is a first conventional example of an electronic device.

FIG. 5 is a circuit diagram showing a power failure detection circuit.

FIG. 6 is a block diagram showing a circuit structure of an electronic cash register which is a second conventional example of an electronic device.

FIG. 7 is a circuit diagram showing a power failure detection circuit.

[Explanation of symbols]

 19 electronic equipment 20 device main body 21-24 external device 25 connection part 27 defect detection means 32 signal output means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // H02H 3/24 A 9061-5G

Claims (1)

[Claims] 1. A power supply for forming at least one connecting portion on an apparatus main body to which one of a plurality of types of external devices having different driving voltages is exchangeably mounted, and which supplies a driving voltage from the connecting portion to the external device. In an electronic device in which a unit is built in the device body, a signal output means for outputting a voltage drop signal to the device body when the drive voltage supplied from the device body falls below a preset allowable voltage is provided to each of the external devices. An electronic device, wherein the electronic device has a built-in failure detection unit that detects a drive failure of the external device when a voltage drop signal is received from the external device.