JP2604651B2 - Optical coupling device, information equipment using the same, and method of controlling optical coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling device (photointerrupter) for detecting the presence or absence of an object without contact, and to an information apparatus such as a copying machine using the optical coupling device and a method of controlling the optical coupling device.

[0002]

2. Description of the Related Art A conventional optical coupling device (photointerrupter) comprises a light emitting element 1, a light receiving element 2, an amplifier 3 and a transistor 4, as shown in FIG. High or Low is output depending on whether or not this light is more than the threshold light amount.

[0003]

In recent years, the number of optical couplers used in information equipment, for example, copying machines, on which optical couplers are mounted, has increased along with their high functions.

To cope with this, as shown in FIG. 6, when a detection state from a detection sensor 12 using the above-described optical coupling device is output to a control device 11 in a copying machine, a power supply line Vcc of each optical coupling device 12 is output. And the ground line GND can be shared and connected to the control device 11, but the signal line (output line V _O ) 19 must be connected in parallel with the control device 11 to the signal line 19 of each optical coupling device 12. However, wiring in the device becomes complicated, which hinders miniaturization of the device.

Since the power is always turned on when using the conventional optical coupling device, the current consumption increases as the number of optical coupling devices used increases (about 10 mA / one optical coupling device). Therefore, it is desired to reduce the current consumption of the optical coupling device.

Further, with the increase in the number of optical coupling devices used, in information equipment such as copying machines, the number of connection points using connectors and the like also increases. For this reason, there has been an increasing demand for checking whether or not the connection points by connectors or the like are securely connected at the time of manufacturing the device or at the time of turning on the power when the device is used.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an optical coupling device capable of simplifying wiring in a device and reducing current consumption, and an information device using the same. Second, it is an object of the present invention to provide a method of controlling an optical coupling device in which a connection check can be performed at the time of turning on the power when manufacturing or using the device.

[0008]

Means for Solving the Problems (1) The means for solving the problems according to the first aspect of the present invention comprises, as shown in FIGS.
In an optical coupling device comprising a light receiving element 10 and an internal control element 13 for controlling the driving of the light emitting element 9 and the light receiving element 10, the internal control element 13 comprises a clock. Each terminal of the clock line CLK and the signal line DI / O is provided, and is transmitted in synchronization with the clock signal of the clock line CLK through the signal line DI / O from the storage circuit 6 for storing its own identification code in advance and the external control device 11. A comparison discrimination circuit 5 for comparing and discriminating whether or not the received identification code matches its own identification code stored in the storage circuit 6, and the comparison discrimination circuit 5 determines whether the identification codes match. When the light emitting element 9 and the light receiving element 1
An output control circuit 30 for supplying power to the power supply 0, a signal generation circuit 31 for generating an identification code reception signal ACK, and a timing control circuit 7 for controlling clock timing.
When the comparison / determination circuit 5 determines that the identification codes match, the signal generation circuit 31 externally controls the detection state result DO input from the light receiving element 10 through the signal line DI / O following the identification code reception signal ACK. The timing control circuit is configured to output the clock signal to the device 11. The timing control circuit synchronizes the clock signal with the code of the signal line by using the code of the signal line at least two times at the beginning of the clock signal for the signal sent from the external control device 11. Is confirmed.

(2) As a means for solving the problem according to claim 2, as shown in FIG. 4, a plurality of optical coupling devices according to claim 1 are provided, and these optical coupling devices are connected to a clock line CLK and a signal line DI / O. The two lines are shared and connected to the external control device 11.

(3) The means for solving the problem according to claim 6 is that, as shown in FIG. 2, the external control device 11 is configured not to generate a clock signal except for the communication of the identification code, and the clock signal is in the high state except for the communication. And L before the identification code
An ow output is input, and a clock signal and an identification code are input to the optical coupling device according to the first aspect.

[0011]

(1) In the means for solving problems according to the first aspect, an identification code which is sent from the external control device 11 through the signal line DI / O in synchronization with the clock signal of the clock line CLK is stored in advance. If the identification code matches the identification code of the external control device 1,
1 can be sent. For this reason, if it is confirmed that the identification code reception signal ACK is sent to the all-optical coupling device, it is known from the external control device 11 that the connection to the optical coupling device has been established. Connection check and connection check at the time of power-on when the device is used.

When the identification code sent from the external control device 11 matches its own identification code stored in advance, only that optical coupling device operates and the other optical coupling devices do not operate. In addition, the current consumption can be significantly reduced as compared with the conventional optical coupling device.

(2) According to claim 2, the signal generating circuit 31
Outputs the detection state result DO to the external control device 11 through the signal line DO together with the identification code reception signal ACK. Therefore, when a plurality of optical coupling devices are connected to the external control device 11, the clock line CLK and Signal line D
I / O can be connected to the external control device 11 by sharing between the optical coupling devices. For this reason, the wiring in the device is simplified as compared with the case where the conventional optical coupling device is used.

(3) In the third aspect, the external control device 1
The identification code sent from 1 is synchronized with the clock signal CKL sent from the external control device 11 as shown in FIG.
The clock signal is in a high state except when the signal is exchanged, and a low output is input before the identification code, and both signals are input to the optical coupler. Then, the timing control circuit 7 of the optical coupling device confirms that the sign signal becomes High when the clock signal falls at the first clock, and that the sign signal becomes Low when the clock signal falls at the second clock. If this timing is OK, the subsequent D
I0 to DI7 are taken in as identification codes. This allows
The synchronization shift due to noise between the clock signal and the code signal on the signal line DI / O can be checked by the optical coupling device.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an optical coupling device showing an embodiment of the present invention, FIG. 2 is a timing chart thereof, and FIG.
Is a sectional view of the optical coupling device.

As shown in the figure, the transmission type optical coupling device (photo interrupter) of the present embodiment includes a light emitting element 9, a light receiving element 10 including an amplifier and an output transistor, and a drive control of the light emitting element 9 and the light receiving element 10. Internal control element 13 that performs
Consists of As shown in FIG. 3, the light emitting element 9 and the light receiving element 10 are mounted on the printed circuit board 14 so as to face each other across the passage 15 of the detected object.
It is soldered to the back side of the printed circuit board 14. These are housed in an exterior case 16, and a projection window 17 and a lighting window 18 are formed in the exterior case 16.

As shown in FIG. 1, the internal control element 13 has four input / output terminals of a power supply line Vcc, a ground line GND, a clock line CLK and a signal line DI / O. (See FIG. 3).

The internal control element 13 has a shift register 34 for reading a data bit sequence sent in synchronization with the clock signal of the clock line CLK from the external control device 11 via the signal line DI / O, and a self-identifying element in advance. A storage circuit (address memory) 6 for storing codes,
A comparison discrimination circuit (address comparison circuit) 5 for comparing and discriminating whether or not the data (identification code) read into the shift register 34 matches the data (own identification code) stored in the address memory 6; An output control circuit 30 for supplying power to the light emitting element 9 and the light receiving element 10 when the address comparing circuit 5 determines that the identification codes match, a timing control circuit 7 for controlling clock timing,
The detection state result DO input from the light receiving element 10 according to the timing determined by the timing control circuit 7 is added to the identification code reception signal ACK, and the signal line DI / O is output.
Signal generating circuit (A
CK generation circuit) 31, an output latch circuit 32, and an output gate circuit 33.

Here, the external control device 11 does not generate a clock signal except when communicating the identification code through the signal line DI / O in order to make the optical coupling device surely grasp the start time of reading the identification code. As shown in FIG. 2, this clock signal is Hi except during communication.
gh state, and a Low output is input before the identification code. Therefore, the timing control circuit 7 controls the signal line DI / O for the signal sent from the external control device 11 two or more times at the beginning of the clock signal.
Is used to confirm the synchronization between the clock signal and the identification code.

A parity signal PTY is added to the end of the 8-bit identification code data bit string sent from the external control device 11, and the internal control element 13 checks the number of bits of this code signal. A parity check circuit 40 is provided to detect a reading error of the identification code.

The address is written by the memory writing control means 35 before the device is mounted on the device having the external control device 11 or after the device is mounted on the device. Then, as this address writing method, R
An AM method, a charge injection method, a junction destruction method, a fuse fusing method and the like can be considered.

Next, the operation of the optical coupling device will be described in detail with reference to the timing chart of FIG.

First, the clock line CLK and the signal line DI / O connected to the external control device 11 maintain a high state when the optical coupling device is not operated.

When it becomes necessary to know the detection state of the optical coupling device, the external control device 11 outputs a clock signal and an identification code synchronized with the clock signal. At this time, only when the state of the DI / O terminal is High at the falling edge of the first clock by the timing control circuit 7, the subsequent DI / O state is changed to DI0 to DI7 (8 in FIG. 2).
) Is read into the shift register 34 as an identification code.

That is, the identification code sent from the external control device 11 is synchronized with the clock signal CKL sent from the external control device 11 as shown in FIG. 2, and this clock signal is used except when the signal is exchanged. The output is put into a High state, and a Low output is inserted before the identification code. The optical coupling device confirms by the timing control circuit 7 that the output is High when the first clock rises and the Low output is when the second clock falls. . If the clock timing is OK, the subsequent eight bits DI0 to DI7 are fetched as identification codes.

With this arrangement, it is possible to check the synchronization deviation due to the noise between the clock signal and the code signal on the signal line DI / O by the optical coupling device.

Further, in this example, the 8-bit DI0 to DI0
The parity signal PTY is added to the I7 code to form a 9-bit code signal, and the number of bits of this code signal is checked by the parity check circuit 40 to detect a parity error. When the occurrence of the parity error is confirmed, the output control circuit 30
O1 power supply line 19 to light emitting element 9 and light receiving element 10
The power is supplied to the light emitting element 9 and the light receiving element 10 only when no parity error is detected. Therefore, errors due to noise in the code signal,
That is, the reading error of the identification code can be checked.

Then, the self-identification code in the address memory 6 and the identification code in the shift register 34 read by the signal line DI / O are compared by the address comparison circuit 5, and the output control circuit 30 Power is supplied to the O1 power supply line 8 of the light-emitting element 9 and the light-receiving element 10 only when they match, and the light-emitting element 9 and the light-receiving element 10 are driven.

Here, when the conventional optical coupling device is used, the power of the all optical coupling device is always turned on. In the present embodiment, however, in FIG. And a light-emitting element 9 and a light-receiving element 10 which are the same as those described above. This part is only an optical coupling device whose identification code sent from the external control device 11 matches its own identification code stored in advance. Operate only for a certain period of time, and the other all-optical couplers whose identification codes do not match do not operate, so that the current consumption can be significantly reduced.

Then, depending on the output of the light receiving element 10, that is, the presence or absence of the detected object, the High or Low signal is output to I
The data is read from the line 19 to the output latch circuit 32. next,
The ACK generation circuit 31 outputs the detection state result DO to the output gate circuit 33 at the timing determined by the timing control circuit 7 along with the identification code reception signal ACK, and the output gate circuit 33 outputs the two signals DO and ACK. The signal is output to the external control device 11 through the signal line DI / O line. In this example, the identification code receiving signal ACK is output in synchronization with the rising edge of the 16th clock, and the detection state result DO is output in synchronization with the rising edge of the 17th clock.

As described above, the detection state result DO is output to the external control device 11 through the signal line DO in accordance with the identification code reception signal ACK, so that the external control device 11 such as a copying machine can be provided with a plurality of optical coupling devices. Are connected, the clock line CLK and the signal line D are connected as shown in FIG.
I / O is shared between the optical coupling devices 12 and the external control device 1
1 can be connected. For this reason, the wiring in the device is simplified as compared with the case where the conventional optical coupling device is used.

Further, since the optical coupler that matches the identification code sends the identification code acknowledgment signal ACK to the external controller 11, it is confirmed that this identification code acknowledgment signal ACK is sent for the all-optical coupler. If the external control device 11
It can be seen from FIG. 2 that the connection to the optical coupling device has been made, so that a connection check at the time of manufacturing the device and a connection check at the time of turning on the power at the time of using the device can be performed.

Here, it is confirmed that no parity error has occurred in the signal line DI / O of FIG. 2, and a certain period of time is passed after power is supplied through the O1 power supply line 8 of the light emitting element 9 and the light receiving element 10. The detection state result DO is output in order to output the detection state result DO in a state where the output 19 of the detected object detection of the light receiving element 10 is stable.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, in this embodiment, the transmission type photointerrupter has been described. However, when the density (toner density) or the tilt angle of the detected object is detected using the reflection type photointerrupter, a command is added to the identification code. The command may be detected by the internal control element, and the supply of power to the light emitting unit and the light receiving unit may be controlled accordingly.

[0036]

As is clear from the above description, (1) According to the first aspect of the present invention, the current consumption of the internal control element is small, so that the current can be reduced. Further, since the connection to the optical coupling device can be confirmed, there is an advantage that a test at the time of manufacturing the device and an initial test at the time of turning on the power of using the device can be performed.

(2) According to the second aspect, since a large number of optical coupling devices can be connected by two lines (clock line and signal line), the number of lead wires can be reduced and the device can be downsized. I do.

(3) According to the third aspect, it is possible to check the synchronization deviation due to noise between the clock signal and the code signal on the signal line.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical coupling device showing one embodiment of the present invention.

FIG. 2 is also a timing chart thereof.

FIG. 3 is a sectional view of the optical coupling device.

FIG. 4 is a wiring diagram in a device when the optical coupling device of the present invention is used.

FIG. 5 is an electric circuit diagram of a conventional optical coupling device.

FIG. 6 is a connection diagram in a device when a conventional optical coupling device is used.

[Explanation of symbols]

 Reference Signs List 5 comparison discrimination circuit (address comparison circuit) 6 storage circuit (address memory) 7 timing control circuit 9 light emitting element 10 light receiving element 11 external control device 12 optical coupling device 13 internal control element 30 output control circuit 31 signal generation circuit (ACK generation circuit 32) output latch circuit 33 output gate circuit 34 input shift register 35 memory write control means 40 parity check circuit

Claims (3)

(57) [Claims] A light-emitting element, a light-receiving element, and an internal control element for controlling driving of the light-emitting element and the light-receiving element;
In an optical coupling device for detecting the presence or absence of an object to be detected in a contactless manner, each of the internal control elements is provided with a clock line and a signal line terminal, and includes a storage circuit for storing its own identification code in advance and an external control device. A comparison discriminating circuit for comparing and discriminating whether or not the identification code sent in synchronization with the clock signal of the clock line via the signal line and the self identification code stored in the storage circuit are matched; An output control circuit for supplying power to the light emitting element and the light receiving element when the determination circuit determines that the identification codes match; a signal generation circuit for generating an identification code reception signal; and a timing control circuit for controlling clock timing. And a signal generation circuit that, when the comparison and determination circuit determines that the identification codes match, identifies the detection state result input from the light receiving element as an identification code reception signal. Is configured to output to an external control device via continuing the signal line, the timing control circuit, for a signal sent from the external control device,
An optical coupling device characterized in that synchronization of the clock signal and the code of the signal line is confirmed by the code of the signal line at least two times in the initial stage of the clock signal. 2. The optical coupling device according to claim 1, wherein a plurality of optical coupling devices are provided, and these optical coupling devices are connected to an external control device by sharing two lines of a clock line and a signal line. Information equipment. 3. An external control device is constructed so as not to generate a clock signal except at the time of communication of the identification code. The clock signal is set to a high state except at the time of communication, and the L signal is output before the identification code.
2. A method for controlling an optical coupling device, comprising: inputting an ow output and inputting a clock signal and an identification code to the optical coupling device according to claim 1.