JPH04189061A - Original reader - Google Patents

Abstract

PURPOSE:To reduce external noise without implementing shielding by providing a communication means transmitting at least part of signals required between a running body unit and a main body through optical transmission. CONSTITUTION:An output of an image sensor 107 is given to a processing section 201, an A/D converter 202 and a P/S converter 203, in which a picture signal is converted into a serial signal and a laser diode 109 is modulated, The above optical signal is received by a light receiving sensor 113 and transferred to a picture processing section 301. A clock signal is sent by a laser diode 110 as an optical processing section 301. Moreover, a synchronizing signal outputted from the processing section 301 is sent as an optical signal by a laser diode 114 and received by a light receiving element 111 provided to a running unit 104 and restored to a synchronizing signal. Thus, even when the distance of the unit 104 is extended, crosstalk is not almost in existence and high speed modulation is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a document reading device, and more particularly to a document reading device used in an image forming device such as an image scanner or a digital copying machine.

[Conventional technology]

For example, in a document reading device that uses an image sensor such as a CCD to read a document placed on a contact glass, the document and the image sensor are moved relative to each other to perform the reading process. In a configuration in which the image sensor side is installed on a traveling body unit and moved, the traveling body unit and the main body are generally electrically connected using a flexible cable, flat cable, etc. in order to connect the electrical system. There is.

[Invention or problem to be solved]

However, in the above-mentioned conventional technology, image signals, clock signals, power supplies, and
In order to transmit various control signals, the connection cable requires a total of 10 to 20 lines. As a result, the cable width becomes wider and the routing distance becomes longer.
It became susceptible to noise and also generated radio wave radiation due to the clock, so it was necessary to provide a strong shield.

In this way, electrically, it is necessary to consider shielding, insulation, and line impedance, and to use a high-strength cable that can withstand many bending and stretching operations and is flexible.
This increases costs, increases space, and complicates the configuration.
There was a problem in that it increased the burden on the entire system.

The present invention has been made in view of the above, and an object of the present invention is to reduce deterioration of image quality due to noise radiation due to image transmission and external noise.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a document reading device that reads an original on a document table by moving a traveling unit equipped with an illumination light source and an image sensor. The object of the present invention is to provide a document reading device provided with a communication means for transmitting at least part of the signals required between the document reading device and the document reading device by optical transmission.

[For production]

In the document reading device according to the present invention, image data, synchronization signals, etc. are transmitted between the stationary side (main body side) and the moving body by means of communication consisting of a combination of a light emitting element such as a laser diode and a light receiving element such as a photodiode. Signal transmission between the unit and the unit can be performed by optical transmission.

Therefore, it is possible to eliminate the flexible harness provided between the traveling body unit and the fixed side or reduce the number of wires, and by transmitting the clock signal optically, external noise can be reduced without shielding, etc. It is also possible to eliminate the need to expand the flexible harness or create a configuration that does not use the flexible harness.

〔Example〕

Hereinafter, embodiments of the present invention will be described from the beginning with reference to the drawings.

FIG. 1 is a front view showing a schematic configuration of a document reading device according to the present invention.

A contact glass 103 for placing a document 102 is disposed on the upper surface of the apparatus main body 101, and a traveling body unit 104 is disposed below it so as to be movable horizontally. The traveling body unit 104 includes a lamp 105 that illuminates the reading surface of the document 102, a SELFOC lens array (SLA) 106 that forms an image of light reflected from the illumination surface by the lamp 105 on a sensor surface, and the SELFOC lens array 10.
6, a printed circuit board 108 on which the image sensor 107 and peripheral circuit components are mounted, a laser diode 109 that sends out optical signals, a laser diode 110,
A light receiving element 11 that receives an optical signal from the device main body 101 side
1.

Additionally, a laser diode 109 is provided on the device main body 101 side.
．． A light receiving sensor 112, a light receiving sensor 113, and a laser diode 114 are arranged opposite to the light receiving sensor 110 and the light receiving sensor 111.
is installed.

The printed circuit board 108 has a copper pattern formed on a base such as polyimide, and the image sensor 10 is attached to the pattern.
7. Attached circuit elements, connectors, etc. are connected. One end of the flexible harness 115 is connected to the connector, and the other end is connected to a connector provided on the device main body 101 side. The flexible harness 115 is
It has flexibility and is long enough to loosen even when the traveling body unit 104 moves back and forth.

In the configuration shown in FIG. 1, when the start button (not shown) is pressed after placing the original 102 on the contact glass 103, the lamp 105 lights up and the traveling body unit 104
starts moving to the right in the figure. Running body unit 104
During the movement of the document 102 , an image of the illuminated portion of the document 102 is read by an image sensor 107 via a lens 106 .

Image data output from the image sensor 07 is transferred to the apparatus main body 101 via a laser diode 109. Further, power, various control signals, and the like are supplied to the traveling body unit 104 via the flexible harness 115.

FIG. 2 is a block diagram showing the configuration of the electrical system of the traveling body unit 104 and the configuration of its peripheral circuits.

Further, FIG. 3 is a block diagram showing the configuration of the electrical system on the device main body 101 side.

The image sensor 107 is connected to a processing unit 20 for processing its output signal, and outputs an analog image signal.

An analog/digital (A/D) converter 202 is connected to the processing section 201, and the read signal is digitized. A
/D converter 202 has parallel/serial (P/S)
Converter 203 and electro-optical converter (EOCI) 204
The output signal of the A/D converter 202 is converted into a serial signal, and further converted into a signal for modulating and driving the laser diode 109. Electrical-optical converter 204
It is desired that the circuit may simply be a simple on/off switching circuit, or that it has switching characteristics that can sufficiently cover the frequency of the image signal when it is serially converted.

Further, a clock signal of the image sensor 107 is generated by the clock generator 205.

The clock generator 205 includes a light receiving sensor 111.
an optical-to-electrical converter (OECI) 206 that outputs a line synchronization signal (LSYNC) based on the output of the clock generator 205; and a clock (CLK) output from the clock generator 205.
An electric-to-optical converter (EOC2) 207 is connected thereto, which performs electric-to-optical conversion to modulate and drive the laser diode 110.

As shown in FIG. 3, an image processing section 301 that performs image processing is provided on the apparatus main body 101 side, and an optical-to-electrical converter (OEC3) 302 connected to the image processing section 301.
The clock (CLK) is obtained from. Light-electric converter 3
02 is connected to the light receiving sensor 112 and generates a clock (CLK) from its output. Also, laser diode 1
An optical-to-electrical converter (○EC2) 303 is connected to the light-receiving element 113 that receives the data sent from 09, and the conversion output is converted to parallel data and sent to the image processing unit 30.
A serial-to-parallel (S/P) converter 304 is provided for transmitting the signal to 1.

Furthermore, an electro-optical converter (EOC3) 30 for converting the line synchronization signal (LSYNC) output from the image processing unit 301 into a signal that modulates the laser diode 114.
5 is provided.

In the configurations shown in FIGS. 2 and 3, the image sensor 1
The output of 07 is subjected to predetermined analog processing by the processing section 201, and is converted into a digital signal by the A/D converter 202. Furthermore, the P/S converter 203
The bit parallel digital image signal is converted to a serial signal and then modulated by the laser diode 109 by an electro-optic converter 204. The optical signal is received by the light receiving sensor 113, and the signal converted by the optical-to-electrical converter 303 is converted into an 8-bit parallel digital image signal by the serial/parallel converter 304, and then transferred to the image processing unit 301. be done.

Furthermore, the tarokku (CLK) generated by the clock generator 205 is sent out as an optical signal from the laser diode 110 by the electro-optic converter 207, which is received by the light receiving sensor 112 installed on the device main body 101 side, and the optical signal is The electrical converter 302 restores the signal to a clock (CLK) signal, which is sent to the image processing unit 301.

Furthermore, the line synchronization signal (LSYNC) output from the image processing unit 301 is sent out as an optical signal from the laser diode 114 by the electro-optical converter 305, and is then sent out as an optical signal by the light receiving element 111 provided on the traveling body unit 104 side. The light is received and restored to a line synchronization signal (LSYNC) by the optical-to-electrical converter 206.

As described above, the advantages of using a laser diode to generate an optical signal are that the size of the light spot does not change, the amount of light does not decrease even if the distance of the traveling unit 104 becomes long, and the ability to connect multiple channels There is almost no crosstalk, and high-speed modulation is possible.

It should be noted that although the invention made by the present inventor has been specifically explained based on Examples, the present invention is not limited to the above-mentioned Examples. For example, the directions of clocks may be reversed. Further, parallel-to-serial conversion of image signals is not a necessary condition of the present invention. Furthermore, it goes without saying that the present invention can also be applied to other types of signals (status information, mode setting signals, etc.).

〔Effect of the invention〕

As explained above, the present invention provides a document reading device that reads an original on a document mounting table by moving a traveling body unit equipped with an illumination light source and an image sensor, in which the traveling body unit and the main body side are moved. Of the required signals,
Since we have provided a communication means that performs at least part of it through optical transmission, it is possible to eliminate the need for a flexible harness between the traveling body unit and the fixed side, or reduce the number of wires, and eliminate external noise without shielding. Furthermore, it becomes possible to eliminate the need to expand the flexible harness or create a configuration that does not use the flexible harness.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the schematic configuration of the document reading device according to the present invention, FIG. 2 is a block diagram showing the configuration of the electrical system of the traveling body unit 104 and the configuration of its peripheral circuits, and FIG. 3 is the main body of the device]01 FIG. 2 is a block diagram showing the configuration of a side electrical system. Explanation of symbols 101 - Apparatus body 102 - Document 104 - Traveling body unit 105 - Lamp 106
-Selfoc lens array 107...Image sensor 108--Printed board 1
09.110,114 - Loser Die Auto 112.11
3,114--Light receiving sensor 115--Flexible harness 2o1-Processing unit 204.207, 305--Electrical-to-optical converter 205--Clock generator 206.302, 303--Optical to electrical converter 301...
Image processing section

Claims (1)

[Scope of Claims] In a document reading device that moves a traveling body unit equipped with an illumination light source and an image sensor to read a document on a document mounting table, a device is required between the traveling body unit and the main body side. A document reading device comprising communication means for transmitting at least a portion of signals by optical transmission.