JP2910806B2 - Image reading 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 image reading apparatus for reading an original while illuminating a portion to be read in a facsimile apparatus or the like.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional device of this type includes a line image sensor 21 for reading an image from a document 1 and a light emitting unit (LED array) 31 for illuminating a portion of the document 1 to be read. And a lighting drive circuit 32 for the light-emitting unit 31. As shown in FIG. 4, after the light-emitting unit starts to be driven to light up at the start of reading, the original 1 which is fed and driven in the sub-scanning direction. Has been read line by line in the main scanning direction, and when the reading is completed, the light emitting unit 31 is turned off accordingly. In FIG. 3, C1 denotes a reading start / end signal, CX denotes a light emitting unit lighting drive control signal, and the light emitting unit 31 is turned on and off in response to the reading start / end signal C1.

[0003]

However, according to such a configuration, there is a problem that the power consumption of the illumination light source is a major factor that hinders the reduction of the power consumption of the apparatus.

[0004] The above problem arises for the following reasons. That is, the light emitting unit 31 serving as an illumination light source is configured using a large number of light emitting elements such as LEDs (light emitting diodes) because it is necessary to illuminate at least the reading range of the line image sensor 21. A large amount of power has been consumed to maintain the lighting of the light emitting unit 31 composed of a large number of light emitting elements.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide an image reading apparatus that has significantly reduced power consumption by reducing power consumption of an illumination light source.

[0006]

In order to achieve this object, the present invention provides an image sensor for reading an image from a document or the like, an LED light source for illuminating a portion to be read, and a transmission path for an output image read by the image sensor. A control panel for instructing the image sensor to start reading, an instruction signal indicating the start and end of reading of the image sensor from the operation panel, and an output obtained from the communication control unit. transmission line busy signal indicating a transmission waiting state of the image, and output means said image sensor to output the signals of the reading section signal performs a reading operation in units of lines, the image sensor from the respective signal output from the output means the reading state to determine the, and lighting control means for generating a lighting drive control signal, the lighting drive control signal from the lighting control means Those having a structure that the LED lighting driving means to quickly perform lighting control of the LED light source based.

[0007]

According to the present invention, a reading signal indicating the start and end of reading according to an instruction from the operation panel unit, a transmission line busy signal indicating a state waiting for transmission of image information, and an image sensor performing reading operation in units of lines. Each signal of the reading section signal
A lighting drive control signal is generated based on the signal, and the lighting drive control signal is used to control the lighting of the LED light source. The status of each reading stop such as reading stop due to waiting or the status of reading interruption can be quickly identified, and the LED is quickly turned on according to these conditions.
The light source is turned on and off.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

In the drawings, the same reference numerals indicate the same or corresponding parts. FIG. 1 shows a schematic configuration of an image reading apparatus according to an embodiment of the present invention, wherein 1 is a document, 21 is a line image sensor for reading an image from the document 1, and 22 is a reading operation of the line image sensor 21. The reading control circuit for controlling, CK1 and CK2 are clock signals for defining the timing of the reading operation of the sensor 21, 31 is a light emitting unit (LED array) as a light source for illuminating the read portion of the document 1, and 32 is the light emitting A lighting drive circuit of the unit 31, a lighting control circuit 33 for controlling the lighting of the light emitting unit 31 via the lighting drive circuit 32, a document feed drive circuit 4, a document feed drive circuit 5, and whether or not the document 1 is at the reading position. , A communication control unit for performing facsimile communication via the telephone line 61 in accordance with a predetermined communication control procedure, and 7 a control panel. Le, 8
Is a main control circuit for centrally controlling the operation of each of the above-described units by a general-purpose control device formed as a semiconductor integrated circuit, a so-called microcomputer.

Here, as shown in FIG. 2, the lighting control circuit 33 includes a reading start / end signal C1 and a driving path busy signal C1.
2. Based on the reading section signal C3, the lighting drive control signal CX (CX = + C1 + C2.
-C3) is created.

The read start / end signal C1 is a signal indicating the start to end of the reading operation, and is generated based on a read command operation from the operation panel 7.

The transmission path busy signal C2 is a signal indicating the state of the communication control unit 6, and indicates a section where transmission of image information to the transmission path is in a waiting state.

The reading section signal C3 is transmitted to the image sensor 2
1 is a signal indicating a line scanning section in which the line reading scanning by 1 is performed. That is, in the image sensor 21 using the CCD, charge accumulation and transfer are repeated every time one line is read. However, a line reading section in which an image is substantially read is when charge accumulation is performed. The image is not read in the charge transfer section performed in the interval.

Only when the read output from the image sensor 21 becomes valid based on the signals C1, C2, and C described above, the lighting drive control signal CX (CX = + C1, + C2, -C3) of the light emitting unit 31. Occurs.

The operation of the image reading apparatus configured as described above will be described below. In the above-described apparatus, as shown in FIG. 2, the light emitting unit 31 is turned off and the power is turned off when the driving path is busy or during the line reading section, even during the reading operation. Consumption is reduced.

As a result, the driving of the illuminating light source can be minimized even during the reading operation, so that the power consumption of the illuminating light source can be greatly reduced by reducing the power consumption.

The lighting drive control signal CX may be generated based on a signal indicating a reading state other than the signals C1, C2, and C3 described above.

The lighting control circuit 33 is configured as an independent unit in the illustrated example, but can be incorporated in the main control circuit 8 by software.

As the illumination light source, a light-emitting element or a light-emitting unit other than the LED can be used as long as it can be instantaneously activated.

[0020]

As apparent from the above description, according to the present invention, the reading signal indicating the start and end of reading by the instruction from the operation panel unit, the transmission path busy signal indicating the image information transmission waiting state, and the image sensor are used. A lighting drive control signal is generated based on each signal of a read section signal for performing a read operation in line units, and the lighting drive control signal is used to control the lighting of the LED light source. Quickly identify the status of the reading, such as the status, the reading stop instruction from the operation panel unit, and the reading stop due to waiting for transmission, or the status of the reading stop, and quickly turn on and off the LED light source according to these conditions. Accordingly, driving of our minimum necessary reading even illumination source during operation
Thus , the power consumption of the illumination light source can be significantly reduced, and the power consumption can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a lighting drive control signal of an illumination light source in the device of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional image reading apparatus.

FIG. 4 is a timing chart showing a lighting drive control signal of an illumination light source in a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Original 21 Line image sensor 22 Reading control circuit 31 Light emitting unit (LED array) as an illumination light source 32 Lighting drive circuit 33 Lighting control circuit 4 Document feed drive circuit 5 Sensor 6 Communication control unit 61 Communication line 7 Operation panel 8 Main control Circuit C1 Read start / end signal C2 Runway busy signal C3 Read section signal CX Lighting drive control signal

Claims (1)

(57) [Claims] 1. An image sensor for reading an image from a document or the like, an LED light source for illuminating a portion to be read, a communication control unit for controlling a transmission path of an output image read by the image sensor, and a start of reading by the image sensor And an instruction signal indicating the start and end of reading of the image sensor from the operation panel unit, a transmission path busy signal indicating a state of waiting for transmission of an output image obtained from the communication control unit, the image Output means for outputting each signal of a reading section signal in which the sensor performs a reading operation in line units; and determining the reading state of the image sensor from the respective signals output from the output means, and controlling the lighting drive. Lighting control means for generating a signal; and lighting control of the LED light source is quickly performed based on a lighting drive control signal from the lighting control means. An image reading apparatus and a Cormorant LED lighting driving means.