JPS5972534A - On/off signal input device - Google Patents

Abstract

PURPOSE:To attain an input of many signals through a simple circuit, by sorting plural devices into groups which are not turned on simultaneously, and supplying the output of each group to a control circuit after applying D/A conversion, then an A/D conversion by successive switching. CONSTITUTION:Plural ON/OFF signal generators 11 are sorted into groups which are not turned on simultaneously, and each device is connected to plural D/A converters 12(1-m) via signal lines 15 for conversion into analog signals. The analog signal is supplied to a channel device 13A via a signal line 16. An A/D converter 13 converts each analog signal supplied to a channel device 13A into a digital signal by the channel switch signal sent from a controller 14 via a signal line 17. In such a way, many ON/OFF signals are supplied to the controller 14 with an extremely simple circuit constitution, so that this signal input device is suitable for a copying machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an on/off signal input device for inputting on/off signals output from various devices such as operating devices and detectors to a control device.

For example, in a copying machine, in order to control each part mechanism and device and obtain a predetermined copying operation, there are various operation switches on the operation panel, a large number of detection switches arranged in the paper conveyance path, the optical mechanism scanning path, etc. , a large number of on/off signals output from various state quantity detectors installed in developing/fixing devices, etc. are input to a digital control device composed of a microcomputer, and these signals are processed based on a control program. A predetermined copying operation is being performed.

In this way, the control device that forms the core of the system requires the manual input of numerous on/off signals output from various parts of the system. Conventionally, the following methods have been used to input these on/off signals: Three methods are known: (1) A method in which one on/off signal is assigned to each input terminal of the control device.

(2) Method using a diode matrix For example, in the case of a 4×4 matrix, as shown in FIG. It inputs on/off signals from the switches 4, and uses a total of eight input/output terminals of the control device 1. In addition, in the case of an 8x8 matrix, a maximum of 64 on/off signals can be input using 8 scanning lines and 8 input lines, and in this case, the number of input/output terminals used is 1.
◎ (3) Method using a multiplexer As shown in FIG. The input line 7 is used to input to the control device 1, and three input/output terminals are used. Also,
Eight on/off signals can be input from one human power line using three control lines, and the number of input terminals used in this case is four.
Become an individual. Furthermore, 16 on/off signals can be taken out to one input line using four control lines, and in this case, the number of input terminals used by the control device 1 is five.

However, each of the above conventional methods has problems as described below.

In the case of (1) above, the number of input terminals is the same as the number of switches, making it difficult to apply to control systems with a large number of switch inputs.In the case of (2) above, the number of input terminals is the same as the number of switches. In addition, input scanning using high-speed pulses is not possible due to stray capacitance and inductance of the lead wires, such as when the distance between the control device 1 and the switch 4 is large.

In the case of (3) above, a multiplexer is required, which increases the number of elements and increases costs.

According to the conventional method, when trying to input a large number of on/off signals to a control device, timing control, selection control, etc. are required, resulting in a complicated circuit configuration and high device cost. O An object of the present invention is to provide an on/off signal input device that can input a large number of on/off signals to a control device with a simple circuit configuration.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a block diagram of an on/off signal input device according to an embodiment of the present invention, in which reference numeral 11 indicates an operation switch;
On/off signal generator such as detection switch, 12 is D/
A converter, ]3 is an A/D converter, and 14 is a control device configured with a microprocessor.〇ON/OFF signal generator 1
1 is divided into a plurality of groups that are not turned on at the same time, and is connected to each D/A converter 12 via a signal line 15. Each D
The /A converter 12 converts the on/off signals output 1/C in time series from the n on/off signal generators 11 divided into groups into corresponding analog signals. Each analog signal is input to the channel device 13A of the A/D i converter 13 via one signal line 16. The A/D converter 13 is connected to this channel device 13A.
Each analog signal input to the controller is sequentially converted into a digital signal based on the channel switching signal input from the control device 14 via the signal line 17, and is output to the control device 14 via the signal #118. The device 14 has n
The on/off signals generated from Xm on/off signal generators 11 are input in a distinguishable state.

At this time, the number of on/off signal generators 11 that can be input to the control device 14 is determined by the resolution of the A/D converter 13. For example, the A/D converter 13 inputs digital signals to the control device 14 via four signals @18.
In the case of an A/D converter with t configuration, it is possible to input 16 digital values to the control device 14. That is, 16 on/off signals can be input to one D/A converter 12, and if the on/off signal generator directly connected to it is not turned on at the same time. , on/off signals from up to 16 on/off signal generators 11 can be input to the control device 14. Furthermore, two signal lines 17 are provided to increase the number of channel switching to four.
If up to four D/A converters 12 are allowed, four D/A converters 12 can be connected to the A/D converter 13, and up to 64 on/off signal generators 11 can be connected. Also, A/D
If the converter 13 has an 8-bit configuration, up to 256 on/off signals can be input through one D/A converter 12i, and if the number of input channels is 4,
Up to 1024 on/off signals can be input.

In this way, one A/D converter 13 and D
/A converter 12 is used in a small number (with a simple circuit configuration, a large number of on/off signals generated one by one in time series for each group can be input to the entire control device 14). become.

FIG. 4 shows a specific example of the on/off signal generator 11 and the D/A converter 12, in which a plurality of resistors R having the same resistance value are connected in series between the reference voltage Vs and the ground. , a plurality of switches S are connected between each node and ground.

As is clear from the figure, in this circuit, for example, when S-1 is turned on, the on/off status of the switches S-2 and subsequent switches becomes irrelevant. Therefore, it cannot be used if all switches are turned on at the same time.

However, if a large number of switches are divided into groups that are not turned on at the same time, and the circuit shown in Figure 4 is assigned to each group, then 1
This analog voltage is converted into a digital signal by the A/D converter 3, and the control device 14 can identify which switch is turned on, and control the corresponding switch. You will be able to do this.

In addition, the on/off signal generator 11 and the D/A converter 1
The specific circuit configuration of 2 is not limited to that shown in Fig. 4, but is shown in Figs.
An arbitrary configuration can be obtained as shown in FIG. That is, the fifth
In the figure, a plurality of resistors R1 to R6 and switches S1 to S5 are connected in series between a reference voltage V8 and the ground via a resistor R, and nodes on the switch side and the resistor side are connected to each other. In FIG. 6, a plurality of series-connected resistors and switches having different values are connected in parallel via a resistor R between the reference voltage VS and the ground.

In FIG. 7, a plurality of resistors are connected in series between the reference voltage (8) and the ground, and all switches are turned on from each node to output an analog voltage. As described above, any of the circuits shown in FIGS. 5 to 7 can provide the same effects as the circuit shown in FIG. 4.

In the above embodiment, the A/D converter 13 and the control device 14 are provided separately, but as shown in FIG. You can also do it. Further, the on/off signal generator 11 is a fourth
It goes without saying that not only the switches shown in Figures to Figure 7 but also non-contact switches using light, capacitance, inductance, etc. may be used.
By dividing the off signal generator into multiple groups that are not turned on at the same time, it is possible to obtain an inexpensive on/off input device that can input a large number of on/off signals to the control device with an extremely simple circuit configuration. .

[Brief explanation of the drawing]

1 and 2 are block diagrams of a conventional on/off signal input device, FIG. 3 is a block diagram of an on/off signal input device showing an embodiment 9Il of the present invention, and FIGS. 4 to 7 are block diagrams of a conventional on/off signal input device. Third
FIG. 8 is a block diagram of an on/off signal input device showing another embodiment of the present invention. ...TfflJ control device, 2...scanning line,
3.7... Input line, 4... Switch, 5... Multi-breather, 6... Control line, 11... On/off signal generator, 12... D/A converter, 13 ...A/
D converter, 13A... Channel device, 15-18.
...Signal line, 19...1-chip microprocessor.

Claims (1)

[Claims] In an on/off signal input device that inputs on/off signals output from a plurality of devices to a control device, the plurality of devices are divided into a plurality of groups that are not turned on at the same time, and an on/off signal is output for each group.・Multiple conversion circuits that convert each off signal into an analog signal, and the analog signals output from each of these conversion circuits are sequentially switched and input,
An on/off signal input device comprising: an A/D converter for converting into a digital signal; and a digital signal output from the A/D converter is input to the control device.