JPH022166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an input/output device that reduces costs by reducing the number of parts used, and improves workability in checking for switch failures.

As a conventional input/output device, for example, various commands (for example,
copy start, interrupt, sorter, etc.), and an input strobe line that outputs a strobe signal that provides input timing for inputting the command signal to a processing unit such as a microcomputer. There is one in which strobe lines are arranged in a matrix and a diode is inserted at each intersection.

In the above configuration, when various command signals are output from the various command switches (provided on the copier console) connected to the input signal line, the time division is determined by the strobe signal of the input strobe line. The command signal is input to a processing unit such as a microcomputer based on input timing. Based on the signal processing results in the processing section, each section of the copying machine is operated to execute the copying operation instructed by the operator.

However, in conventional input/output devices, a diode for timing control is inserted at each intersection of the input signal line and the input strobe line to input the command signal at the timing determined by the strobe signal, so the number of parts used is There is a limit to the reduction in the number of commands, and in order to check for failures in the various command switches, it is necessary to use a tester etc. to check while synchronizing with each strobe signal.
There is a limit to the improvement of check workability.

The present invention has been made in view of the above,
In order to reduce costs by reducing the number of parts used, and to improve the workability of checking for failures of each operation switch, we have developed a system that connects gates that operate at predetermined time-sharing timings to input ports of signal processing units such as microcontrollers. An input/output device for a copying machine is provided, in which an input switch is disposed between the gate and the display diode, and the input switch is checked between the gate and the display diode.

The input/output device for a copying machine according to the present invention will be explained in detail below.

FIG. 1A shows an embodiment of the present invention, in which input ports to a microcomputer 1 (as shown in the figure, input/output interface, ROM (read only memory), RAM (random access memory), CPU (central processing unit) Each switch of the second group of switches 2 and 3 inputs to φ.1, 2...7 via connection points _P1 , _P2 ... _P8 , and the other terminals of switches 2 and 3
Connected to NAND gates 4 and 5, connection point
P ₁ , P ₂ ...P ₈ is the second group of display diodes 6, 7
are connected to the diodes a, b, c...h (FIG. 1b) via limiting resistors _R1 , _R3 ... _R8 . Microcomputer 1 also has two digit outputs D ₁ and D ₂
and eight segment outputs a, b, c...h, and transistors 1 through inverters 8 and 9.
0, 11 (transistors 10, 11 are
It is a PNP type, and the collector is a diode 6 with two groups,
7) inverters 12, 13...
Each diode a, b, c, . At the same time, the two digit outputs D ₁ and D ₂ are input to NAND gates 4 and 5,
Also, the eight segment outputs a, b, c...h are
The signal is input to a NOR gate 20, and the output of the NOR gate 20 is input to NAND gates 4 and 5.

Note that R ₉ , R ₁₀ , . . . R ₁₆ are resistors for setting input levels, and are set to about 20 times as large as R ₁ , R ₂ , . . . R ₈ .

The operation of the above configuration will be explained with reference to FIG. 2 A and B as follows.

(B) In the case of normal operation (Figure 2 B) Microcomputer 1 based on the normal operation program stored in the ROM (based on the processing results of the CPU)
outputs digit signals 100, 200 from digit outputs D ₁ and D ₂ and segment outputs a, b, c...h
A segment signal 300 is output. When the segment signal 300 is “1”, “0” is sent, and when it is “0”, “1” is sent from the NOR gate 20 to the NOR signal 40
It is output as 0 and input to NAND gates 4 and 5. The NAND gate 4 outputs the strobe signal 500 of "0" only when the digit signal 100 and the NOR signal 400 are both "1", and the NAND gate 5 outputs the strobe signal 500 of "0" when both the digit signal 200 and the NOR signal 400 are "1".
A strobe signal 600 of "0" is output only when . When the strobe signal 500 is "0", the switch signal 700a of switch group 2 is input, and when the strobe signal 600 is "0", the switch signal 700a of switch group 3 is input.
switch 700b is input, thereby
For example, the number of copies, etc. can be displayed using two groups of display diodes 6 and 7.

(b) In the case of input check operation (Figure 2 b) Based on the input check operation program stored in the ROM, microcomputer 1 (based on the processing results of the CPU) outputs digits D ₁ , D ₂ , 100, 200. and segment outputs a, b, c...h
A segment signal 300 that is always "0" is output. By “0” of segment signal 300
Since the NOR signal 400 is always “1”,
NAND gates 4 and 5 output strobe signals 500 and 600, which are inverted versions of digit signals 100 and 200. Therefore, "0" of the strobe signal 500
By turning on switch group 2 at the timing of , the corresponding diodes a, b, c, . . . of diode group 6 are turned on.
h can be lit, strobe signal 60
When the switch group 3 is turned on at the timing of “0” of 0, the corresponding diode a of the diode group 7 is turned on.
Since the switches b, c, . . . h can be turned on, failure of each switch in the switch groups 2 and 3 can be detected by the non-lighting of the diodes.

Note that, unlike the above embodiment, input ports φ, 1, 2...7 and segment outputs a, b, c...
If h is also used, the number of input/output lines can be further reduced.

As explained above, according to the input/output device of the present invention, an input switch is arranged between a gate that operates at a predetermined time division timing and an input port of a signal processing section such as a microcomputer, and Since the input switch is checked between the diodes, the number of parts used can be reduced to reduce costs, and the workability of checking for malfunctions of each operation switch can be improved.

[Brief explanation of drawings]

FIGS. 1A and 1B show an embodiment of the present invention, in which A is an overall circuit diagram and FIG. 1B is an enlarged view of a display diode section. FIGS. 2A and 2B show time charts of one embodiment of the present invention, in which A shows a normal copying operation and B shows an input check, respectively. Explanation of symbols: 1... Microcomputer, 2, 3... Input switch group, 6, 7... Display diode group, 4, 5...
NAND (strobe means).

Claims (1)

[Scope of Claims] 1. A signal having a plurality of input switches, an input section connected to each output section of the input switch, and a display signal output section that outputs a plurality of display signals according to the operation of the input switch. a processing section; a gate into which the plurality of display signals is input and whose NOR signal output section is connected to the other end of the output section of the plurality of input switches; and a gate connected to the display signal output section and whose other end is connected to a power source. a plurality of display diodes connected to perform display; a connecting means for respectively connecting output lines connected to the display signal output section of the display diode and an output section of the input switch; display signal output means for turning off all of the display signals, and in an input check operation mode, when the input switch is activated, the display diode connected to the input switch is driven by the gate. An input/output device characterized by: 2. The input/output device according to claim 1, wherein the plurality of display diodes constitute a segment display. 3. The input/output device according to claim 1, wherein the plurality of input switches are time-divisionally driven by a plurality of gate circuits that output strobe signals.