JPS58201128A - Input and output device of copying machine - Google Patents

Abstract

PURPOSE:To find easily a fault of a switch, by providing the switch between a gate which operates on time-division basis and the input port of a signal processing part, and checking a switch for input between the gate and a diode for display. CONSTITUTION:A microcomputer 1 outputs signals 100 and 200 as digit outputs D1 and D2 and also outputs an L-level signal 300 from segment outputs (a), (b)- (h) all the time by an input check program stored in an ROM. The signal 400 of the NOR gate 20 which operates on time-division basis goes up to a level H and NAND circuit 4 and 5 output strobe signals 500 and 600 obtained by inverting the digit signals 100 and 200. Switch groups 2 and 3 are turned on at the L- level timing of the signals 500 and 600 to turn on corresponding diodes (a), (b)- (h) in diode groups 6 and 7. Consequently, a fault of a switch in the switch groups 2 and 3 is detected easily from diodes which are turned off.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an input/output device for a copying machine in which the number of parts used is reduced to reduce costs, and the workability of checking for switch failures is improved.

Conventional input/output devices for copying machines include, for example, input signal lines through which the operator switches in various commands necessary for operating the copying machine (e.g., copy start, interrupt, sorter, etc.) and processing units such as microcomputers. Some devices include an input strobe line that outputs a strobe signal that provides the input timing for inputting the command signal, and the input signal line and the input strobe line 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-sharing input timing determined by the strobe signal of the input strobe line Based on this, the command signal is input to a processing section such as a microcomputer. Based on the signal processing results in the processing section, each section of the copying machine is operated to execute the night cold operation commanded by the operator.

However, in conventional input/output devices for copying machines, there is a signal at each intersection of the input signal line and the input strobe line.

- Input the command signal at the timing determined by the switch signal Because the ioode used by J is inserted, there is a limit to the reduction in the number of parts used, and the various command switches are checked for failures, etc. In order to do this, it is necessary to perform the check using a tester or the like while synchronizing with each strobe signal, which limits the improvement of the workability of the check.The present invention was 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 malfunctions of each operation switch, we have developed an input board for the signal processing section of the gate and microcomputer, etc., which operate at predetermined time-sharing timings. 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. 1(a) shows an embodiment of the present invention, in which an input port to a microcomputer 1 (as shown in the figure, an input/output interface,
(includes IQM (read-only memory), RAM (random access memory), and CPU (central processing unit))
φ, 1, 2...7 has 2 groups of switches 2
．． Each switch of 3 is a connection point P,, P2...P8
The other terminals of switches 2 and 3 are connected to NAND gate 4.5, and the connection points P1, P2...
......P8 is each diode a, b, c-...h of the second group of display diodes 6.7 (Fig. 1 (
(b)) Limiting resistors R1, R3...R8
connected via. Microcomputer I also has two digit outputs D1. D2 and 8 segment outputs B, b, c.
...has h'6 and drives transistor IQ, 11 through inverter 8.9tl.
, 11 are PNP type, and the collectors are connected to two groups of diodes 6 and 71C) Inverters 12, 13, and
Each diode a, b, c of the second group of display diodes 6.7 through 19...h
Fully drive (inverter 8#9 and 12, 13...
...19 shall be of open collector type).

At the same time, two digit outputs D1. D2 is input to the NAND gate 4°5, and 8 segment outputs a, b, c...
...H is input to the NOR gate 20, and the output of the NOR gate 20 is input to the NAND gate 4.5.

Note that R9, 1tlo...l1ls is a resistor that sets the input level, and R1aR2m...R
It is set to about 20 times 8.

In the above configuration, the operation will be explained with reference to FIGS. 2(a) and 2(b) as follows.

(a) In the case of normal operation (Figure 2 (a)) Based on the normal operation program stored in ROM K, the microcomputer 1 (
(based on the processing results of the CPU) outputs a digit signal 100.200'e from the digit output DI and D2, and a segment signal 300 from the segment outputs a, b, c...h.
Output. “0” when the segment signal 300 is “1”
” is “0”, “1” is NO from the NOR gate 20
It is output as an R signal 400 and input to a NAND gate (4.5). 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 the digit signal 200.
The strobe signal 600 of "0" is output only when both the and NOR signal 400 are "1". strobe signal 50
When strobe signal 600 is "0", the switch signal 700a of switch group 2 of switch 4 is input, and when strobe signal 600 is "0", switch 70 of switch group 3 is input.
0b is input, so that, for example, the number of copies, etc.' can be displayed by two groups of display diodes 6.7.

(b) In the case of input canonical operation (Fig. 2 (b)) Based on the input check operation program stored in (2), the microcomputer i (based on the processing result of the CPU) outputs digit D1.
D2100.200 is output, and a segment signal 300 which is always "o" is output from the segment outputs a, b, c, . . . h. segment signal 300
Since the NOR signal 400 is always "0" due to the "0" of the NAND gate 4.5, the NAND gate 4.5 outputs the strobe signal 500.600 which is an inversion of the digit signal 100.degree.

Therefore, by turning on the switch group 2 at the timing of "0" of the strobe signal 500, the corresponding diodes RO, b, c, h, etc. of the diode group 6 can be turned on, and the strobe signal At the timing of "0" of 600, the corresponding diodes in diode group 7 can be turned on by turning on s, inch group 3. It is possible to detect a failure in each switch in switch groups 2 and 3.

Note that, unlike the above embodiments, the input port φ.

1.2...7 and segment outputs a, b, c...
...If h6 is also used, the number of input/output lines can be further reduced.

As described above, according to the input/output device for a photographic camera of the present invention, an input switch is disposed between a gate that operates at a predetermined time division timing and an input port of a signal processing section such as a microcomputer, @-8 between the gate and display diode
-~ - Summary Since the input switches are checked, it is possible to reduce the number of parts used, thereby reducing costs, and to improve the workability of checking for malfunctions of each operation switch.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show an embodiment of the present invention, in which (a) is an overall circuit diagram and the middle part is an enlarged view of a display diode section. FIGS. 2(A) and 2(B) show time charts of one embodiment of the present invention, in which (A) shows a normal copying operation and (B) shows an input check operation, respectively. Explanation of symbols 1...Microcomputer 2.3...Input switch group 6.7...Display diode group 4.5...NAND (strobe means) Patent applicant Fuji Xerox Co., Ltd. )

Claims (1)

[Scope of Claims] A signal processing unit that outputs a display signal in accordance with the operation of the input switch when the input switch is operated, a display unit that displays in accordance with the display signal, and a display unit based on the control of the signal processing unit. and a strobe means for giving an actuation timing for actuating the input switch, and in an input check operation mode, when the input switch is actuated, the output of the strobe means is given to the display section to display a display according to the actuation of the input switch. An input/output device for a copying machine, which is characterized in that: