JP2002237929A - Image reader, image reading system, controller, and methods for them, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader, having a simple configuration, without the need for providing current adjustment means by modes of a light-emitting element for each original lighting, in the case of reading a black-and-white original with a color image sensor of a light source changeover type. SOLUTION: LEDs of R(red), G(green) and B(blue) colors are maintained at turn-on duty ratios, equal to those at color image reading, and are turned on simultaneously or in succession, with the turn-on period reduced to 1/3, so that the forward currents of each of the R, G, B LEDs is maintained equal in the color image reading mode and in the black-and-white original reading mode.

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 capable of reading two types of color originals and black and white originals used for facsimile machines and scanners.

[0002]

2. Description of the Related Art A color original reading apparatus of this type is provided with LEDs having light emission characteristics of three primary colors of R (red), G (green), and B (blue). There is known a light source switching type color image sensor that obtains a color signal corresponding to a document by extracting a signal from a sensor element each time light is emitted.

Such a light source switching type color image sensor is driven by an image sensor driving circuit 1 shown in FIG.
01. In the figure, reference numeral 200 denotes a light source switching type color image sensor unit, 102 denotes a main controller for controlling driving of the light source switching type color image sensor unit 200, and 103 denotes a control signal X based on a control signal CNT from the main controller 102.
A control signal generating circuit for generating SH and MCLK, an LED drive control unit for generating signals φR, φG, and φB for controlling the lighting of each of the R, G, and B LEDs from the control signal CNT and the control signal XSH; Control signal XSH, MC
Signals SP and CL for controlling the driving of the sensor array from LK
This is a sensor array drive control unit that generates K.

In the image sensor driving circuit having such a configuration, first, the control signal CNT corresponding to the reading mode is output to the control signal generating circuit 103 and the LED driving control circuit 104 by the main controller 102, and the R signal corresponding to the reading mode is output. , G, B LEDs, and controls the sensor array.

First, in the color original reading mode, control signals φR, φG, φB and SP, CLK as shown in FIG. 36 are output from the image sensor driving circuit 101 to the light source switching type image sensor unit 200. The following reading is performed by such a control signal.

That is, first, an LED of R is generated by a signal φR.
Only the start pulse SP and the clock pulse C
The operation of the sensor array is started by LK, and an R signal is accumulated in each pixel on the sensor array. Then, after the accumulation period t _ron12 of the R signal has passed, the signal φR causes the LED of R to be emitted.
Is turned off, the G LED is turned on by the signal φG, the start pulse SP is input again, and the R signal already accumulated in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels. The data is sequentially output to the outside one pixel at a time.

At this time, a G signal is simultaneously stored in each pixel on the sensor array. Then, the accumulation time t of the G signal
_{After gon12,} the LED of G is turned off by the signal φG,
After the LED of B is turned on by the signal φB and the start pulse SP is input again, the G signal already accumulated in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels, and then one pixel Are sequentially output to the outside.

At the same time, a B signal is accumulated in each pixel on the sensor array. Then, the accumulation time t of the B signal
_{After bon12,} the LED of B is turned off by the signal φB,
After the R LED is turned on by the signal φR and the start pulse SP is input again, the B signal already accumulated in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels, and then one pixel. Are sequentially output to the outside.

At this time, the image sensor unit 200
Has moved to the next reading line, and the same R, G,
The operation for obtaining the B signal is performed. By repeating this series of operations while moving the image sensor unit 200 line by line in the sub-scanning direction, a color image on the entire document surface is read.

[0010] In FIG 36 R, G, lighting time of each LED of _{B t ron12, t gon12, t} bon1 2, R, G, sensor output period _{B t r12, t g12, t} b12 is _t ron12 = t
_{gon12 = t bon12 = t r12 =} t g12 = has become t _b12, this R for each color image sensor unit,
The R, G, and B LEDs are adjusted in the same LED lighting time as the sensor output period for adjusting the forward current of each LED and outputting signals for all pixels.
A predetermined sensor output level is obtained for each of G and B.

Next, in the black-and-white document reading mode,
From the image sensor drive circuit 101, as shown in FIG.
The control signals φR, φG, φB and SP, CLK turn off the light source.
Output to the replaceable image sensor unit 200
And the lighting time t of each LED of R, G, B
_ron13 , T_gon13 , T_bon13 And black and white output period t_w13 Is
t _ron13 = T_gon13 = T_bon13 = T_w13 And t
_ron13 ≠ t_ron12 It is. This is for reading one line
R, G, B LEDs are turned on at the same time
ED lighting duty ratio is different from color reading
And one of R, G, and B for color reading
When a certain sensor output is obtained when
The amount of irradiation is adjusted so that
In order to read the manuscript, the forward current of each LED of R, G, B and
And the lighting time must be changed from the color reading mode.
It is not.

The reading of a black-and-white original by the control signal shown in FIG. 37 is performed by first using R, G, B signals R, G, B.
All three types of LEDs are simultaneously turned on, and the operation of the sensor array is started by the start pulse SP and the clock pulse CLK, and a W signal corresponding to a monochrome image is accumulated in each pixel on the sensor array. When the reading of the original for one line is completed, the image sensor unit 200
Moves to the next read line, again receives a start pulse SP, and after the W signal already stored in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels, one pixel at a time It is sequentially output to the outside.

At this time, all the three types of RGB LEDs are lit, and the W signal of the next read line is accumulated in each pixel on the sensor array. When the reading of the original for one line is completed, the image sensor unit 200
Moves further to the next read line, the start pulse SP is input again, and the W signal already accumulated in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels. Are sequentially output to the outside. By repeating such a series of operations while moving the image sensor unit 200 one line at a time in the sub-scanning direction, monochrome reading of the entire document surface is performed.

Further, in the conventional color image sensor,
R, G, and B color filters are arranged on the opening of the sensor unit, and a plurality of color filters are arranged in a line. The light source needs to uniformly irradiate light with high luminance over the entire width of the read document, and a light source having an emission wavelength that matches the spectral sensitivity of the color filters of the sensor units R, G, and B is required.

In a color image sensor having such a configuration, when reading a black-and-white document between color documents, a light source for uniformly irradiating light with high luminance without distinction between a color document and a black-and-white document is necessary. The decrease in illuminance due to light deterioration affects the life of the image sensor.

[0016]

By the way, in the conventional light source switching type color image sensor, R, G, and B are used.
A color image can be reproduced by sequentially illuminating the three LEDs and irradiating the reading line of the original, and taking out the output of the line sensor, and further taking out the output of the line sensor by simultaneously emitting the R, G, B LEDs. Thus, it was also possible to read a black and white image.

However, when reading a black-and-white image, the R, G, and B LEDs continuously emit light simultaneously.
R, G, B L under the same conditions as when reading a color original
When the ED was turned on, there was a problem in reliability. Therefore, when reading a black-and-white document, LE is longer than when reading a color document.
R, G, B LEDs by lowering the current flowing to D
However, the reliability at the time of simultaneous lighting is maintained, but this complicates the LED drive circuit and the signal processing circuit and causes an increase in cost.

In a conventional color image sensor, expensive color filters of R, G, and B are required to be arranged on the opening of the sensor unit. When reading a black-and-white document between color documents, both a color document and a black-and-white document are read. A light source for uniformly irradiating light with high brightness is required without any distinction, and there has been a problem that a decrease in illuminance due to light deterioration of the light source affects the life of the image sensor, and the quality reliability of the entire device is reduced.

The present invention has been made in view of the above-mentioned problems, and controls the light-emitting elements to emit light at the same drive timing and the same drive current when reading a black-and-white document and when reading a color document. Thus, high-speed black-and-white document reading can be realized without increasing the cost of a driving circuit, a signal processing circuit, and the like.

It is another object of the present invention to provide an image reading apparatus which has a long life and does not lower the quality reliability of the entire apparatus.

[0021]

An image reading apparatus according to the present invention is configured as follows.

(1) A plurality of light sources having different emission wavelengths, photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources, and switching means for switching between a first mode and a second mode; In both cases where the first mode is selected by the switching unit and when the second mode is selected by the switching unit, control is performed such that the signal stored in the first line period is read by the photoelectric conversion unit. Reading control means for supplying a lighting control signal so as to sequentially turn on the plurality of light sources in each of the first line periods in the first mode, and the first mode in the second mode. Lighting control means for supplying a lighting control signal so as to sequentially turn on the plurality of light sources during the line period, and wherein the lighting control means includes a first mode. The duty ratio of the lighting control signal for lighting the plurality of light sources is not changed between the mode and the second mode, and the lighting time of the second mode is the same for each light source as compared with the lighting time of the first mode. Change to be shorter in proportion.

(2) A plurality of light sources having different brightnesses, photoelectric conversion means for photoelectrically converting a subject image illuminated by the light sources, switching means for switching between a first mode and a second mode, and the switching means In both the case where the first mode is selected and the case where the second mode is selected by the switching means, lighting control means for sequentially lighting the plurality of light sources; and in the first mode, The signals stored in the photoelectric conversion means are sequentially read out in the first line period in response to the lighting of each light source by the lighting control means, and in the second mode, the plurality of light sources are turned on by the lighting control means. Correspondingly, the signal added and accumulated by the photoelectric conversion means is controlled so as to be read once in the first line period every time a plurality of light sources are sequentially turned on, The serial first line period; and a read control means for the period corresponding to the lighting time in the first mode of the darkest light source among the plurality of light sources.

(3) A method for controlling an image reading apparatus, comprising: a plurality of light sources having different emission wavelengths from each other; and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources. A switching step of switching between a second mode and a first mode in the switching step, and a first mode by the photoelectric conversion means in both a case where the second mode is selected in the switching means. A read control step of controlling to read a signal accumulated in a line period, and in the first mode, a lighting control signal is supplied so as to sequentially light the plurality of light sources for each of the first line periods, In the second mode, a lighting control signal is supplied so that the plurality of light sources are sequentially turned on during the first line period. A lighting control step of lighting the plurality of light sources in the first mode and the second mode without changing a duty ratio of a lighting control signal for lighting the plurality of light sources. The lighting time of the second mode is changed to be shorter at the same rate for each light source than the lighting time of.

(4) A method for controlling an image reading apparatus having a plurality of light sources having different brightnesses and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources, the method comprising a first mode and a second mode. A switching step for switching between the modes, a case where the first mode is selected in the switching step, and a second step in the switching step.
A lighting control step of sequentially lighting the plurality of light sources in both cases where the mode is selected, and the photoelectric conversion means corresponding to lighting of each light source in the lighting control step in the first mode. , The signals accumulated in the photoelectric conversion means are sequentially read out in the second mode in correspondence with the lighting of the plurality of light sources by the lighting control means in the second mode. And the readout is controlled so that the readout is performed once in the first line period every time the light is sequentially turned on, and the first line period is set to the first darkest light source among the plurality of light sources.
And a read control step of setting a period corresponding to the lighting time in the mode.

(5) An image which can be connected to a control device via an interface with an image reading device having a plurality of light sources having different emission wavelengths from each other and a photoelectric conversion means for photoelectrically converting a subject image illuminated by the light source. A reading system, wherein the control device stores a light source control program corresponding to a first mode and a light source control program corresponding to a second mode for performing light source lighting control different from the first mode. And reading out a program corresponding to each of the case where the first mode is selected and the case where the second mode is selected from the memory, and responding to the mode via the interface according to the read out program. Lighting control means for controlling lighting of the plurality of light sources.

(6) A control device connectable via an interface to an image reading device having a plurality of light sources having different emission wavelengths from each other and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources. A memory storing a light source control program corresponding to the first mode and a light source control program corresponding to a second mode for performing light source lighting control different from the first mode; A program corresponding to each of the case where the second mode is selected and the case where the second mode is selected are read out from the memory, and the lighting control of the plurality of light sources corresponding to the mode is performed via the interface according to the read program. Lighting control means.

(7) An image reading apparatus comprising: a plurality of light sources having different emission wavelengths from each other; photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources; and an interface connectable to a control device. Receiving means for receiving an instruction of the control device based on a program corresponding to each of a case where a first reading mode is selected and a case where a second reading mode is selected; Lighting means for performing lighting control according to the following.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 and 2
1A and 1B are an external perspective view and a cross-sectional view illustrating an example of a light source switching type color image sensor embodying the present invention, in which R, G, and B color LED lights are made incident from an end face of a light guide, and uniform light is emitted from a side face. And a sensor array in which a short focus imaging element array and a plurality of sensor elements are arranged in a straight line.

The configuration of the main part of such a color image sensor 200 is such that a transparent glass plate 21 in contact with the document surface is mounted on the upper part of the frame 20, and the emitted light 12 of the light guide light source 3 provided in the frame 20. Is reflected on the original surface in contact with the upper surface of the transparent glass plate 21 and the optical system 29 through which the reflected light 13 from the reading surface of the original passes, and the sensor array 1 provided on the substrate 19 corresponding to the optical system 29 Is provided in the frame 20, and the optical system 29 is provided.
Employs a short-focus imaging element array represented by, for example, a product name "SELHOC lens array" (manufactured by Nippon Sheet Glass Co., Ltd.).

The sensor array 1 has a multi-chip type in which a plurality of line sensors 2-1, 2-2,..., 2-15 are arranged in a straight line on the substrate 19 as shown in FIG. This is called a line sensor, and the entire sensor array 1 is covered with a protective film 26. A board 19 on which such a sensor array 1 is mounted is supported by a bottom plate 25 engaged with a frame 20 and is connected to a flexible board 23 via a flexible wiring 28. A connector 22 for input / output of signals and the like is provided, and a flexible board 23 is attached to the frame 20.

FIGS. 4 and 5 are side and cross-sectional views, respectively, of the light guide light source 3. In FIG. 4, reference numeral 4 denotes an incident surface, 5 denotes a light guide portion for propagating light incident from the incident surface 4 in the longitudinal direction of the light guide light source 3, and 6 denotes an original light which propagates through the light guide portion 5. A reflection part for diffusing and reflecting in the direction,
Reference numeral 7 denotes a light condensing unit for condensing the reflected light from the reflecting unit 6 on a portion of the document to be read. Reference numerals 41 and 42 denote LED substrates attached to the light incident surfaces 4 at both ends of the light guide light source 3, on which LED packages 81 to 83 containing LED chips 31 to 33 are mounted.

In FIG. 5, a rectangle indicated by a dotted line indicates an LED package 8 on the LED boards 41 and 42.
Positions 1 to 83 are shown. This LED package 8
The light emitted from the LED chips 31 to 33 included in the light guides 1 to 83 is designed so as not to be directly incident on the reflector 6 provided below the light guide light source 3.
Are formed such that the LED light is totally reflected at both ends in the lateral direction of the light guide member 5, so that the internal reflection is repeated many times inside the light guide light source 3, and the longitudinal direction of the light guide portion 5 is reduced with a very small amount of light loss. Is propagated.

After several internal reflections, when the light enters the reflecting section 6, the light is diffused and reflected in the direction of the document surface, is further condensed by the light collecting section 7, and irradiates only the vicinity of the reading surface of the document. . At this time, the luminous flux incident on the reflecting portion 6 is indirect light reflected inside the light guide light source 3, and the aperture is adjusted in the longitudinal direction so that the irradiation light on the document becomes uniform. The uniformity of the illuminance on the document surface is improved.

FIG. 6 shows the LE on the LED boards 41 and 42.
Arrangement of D packages 81 to 83 and LED package 8
The arrangement of the LED chips 31 to 33 in 1 to 83 is shown, and one LED chip is stored in one LED package. Also, one LED chip is included in each LED substrate for each of the R, G, and B emission colors. Note that the emission color of the LED chip is not limited to R, G, and B, and may be, for example, yellow, cyan, or magenta.

In FIG. 6, 31 is an LED chip having an R emission color, 32 is an LED chip having a G emission color, and 33 is a B chip.
LED chip having a light emission color of Then, these LED chips 31 to 33 on the LED boards 41 and 42 are
Lighting and extinguishing can be controlled at independent timing for each of the R, G, and B emission colors.

FIG. 7 shows the color image sensor 2 described above.
This is an example of a system in which an image reading apparatus 110 having a built-in 00 is connected to a personal computer 130 to form a system.
112, a CPU that controls the entire image reading apparatus 110;
Reference numeral 00 denotes a color image which includes the light source and the CCD line sensor described above, and converts an image of a document into an image signal.
Reference numeral 116 denotes an analog signal processing circuit that performs analog processing such as gain adjustment on an analog image signal output from the color image sensor 200.

Reference numeral 118 denotes an analog signal processing circuit 11
A / D converter for converting the output of 6 into a digital signal, 1
Reference numeral 20 denotes an image processing circuit that performs image processing such as shading correction processing, gamma conversion processing, and scaling processing on output data of the A / D converter 118 using the memory 122. Reference numeral 124 denotes an image processed by the image processing circuit 120. An interface for outputting digital image data to the outside. The interface 124 is, for example, SCSI or Bi-
It is connected to a personal computer 130 in accordance with a standard adopted by a personal computer such as Centronics.

The personal computer 130 is equipped with a magneto-optical disk drive, a floppy (registered trademark) disk drive, or the like as the external storage device or the auxiliary storage device 132. 134 is a personal computer 1
A display 133 for displaying work on the computer 30 is a mouse / keyboard for inputting commands and the like to a personal computer. Reference numeral 135 denotes an interface for exchanging data, commands, and status information of the image reading device between the personal computer and the image reading device.

The personal computer 130 can input a color reading / monochrome reading instruction to the image reading device from the mouse / keyboard 133. When an instruction for color reading / monochrome reading is input by the mouse / keyboard 133, the CPU 136 transmits a color reading / monochrome reading command to the image reading apparatus via the interface 135. Then, according to the light source control program information stored in the ROM 137, the personal computer 130 performs light source lighting control according to a reading mode as described below. The light source control program reads the program stored in a storage medium such as a magneto-optical disk or a floppy disk loaded in the auxiliary storage
136 may be executed.

FIG. 8 is a timing chart of the driving pulse of the image sensor unit and the output of the image sensor according to the present embodiment, and shows the operation of the image sensor when reading a black-and-white document using a light source switching type color image sensor. It is. FIG. 9 shows the relationship between the allowable value of the forward current of the LED and the lighting duty ratio.

Here, assuming that all the three kinds of LEDs of R, G, and B have the allowable values of the forward current as shown in FIG. 9, in the color original reading mode shown in FIG.
Since the lighting duty ratio of each of the R, G, and B LEDs is about 33%, the allowable forward current in this case is about 45 mA.
Becomes On the other hand, in the black-and-white original reading mode shown in FIG. 37, since the lighting duty ratio of each of the R, G, and B LEDs is about 100%, the allowable forward current in this case is about 25 mA.

FIG. 10 shows the relationship between the LED forward current and the relative luminous intensity. It can be seen that the luminous intensity increases as the LED forward current increases. In the case of reading a color original, the data amount may be three times as large as that of reading a black-and-white original. Therefore, it is necessary to ensure the illuminance of the original surface as much as possible and read the data at high speed.

For this reason, when reading a color original, a current close to the allowable forward current of 45 mA flows in many cases.

At the LED drive timing of this embodiment shown in FIG. 8, the lighting duty ratio of each of the R, G and B LEDs is about 3 which is the same as in the color original reading mode.
Since it is 3%, it is not necessary to change the forward current of the LED in the monochrome original reading mode even if the allowable value limit of 45 mA flows in the color original reading mode, and it is possible to drive with the same current value.

Next, a light source control flowchart in this embodiment is shown in FIG. First, when the reading mode is input in step S1, if the mode is the monochrome reading mode, the process proceeds to step S2. If the image of the first line is to be read, in step S3, the LED of R is generated by the signal φR.
Starts lighting for a tron1 period. At the same time, the operation of the sensor array is started by the start pulse SP and the clock pulse CLK. Then, the process proceeds to steps S4 and S5, and the signal G is turned on by the signal φG and the signal φB during the tgon2 period.
The B LED is turned on for a period of tbon3, during which a W signal corresponding to a monochrome image is accumulated in each pixel on the sensor array. When reading of the original for one line is completed, the image sensor unit 200 moves to the next reading line, and a start pulse SP is input again. In step S6, the W signal already accumulated in each pixel on the sensor array is output. After all the pixels are simultaneously transferred to the analog memory on the sensor array, they are sequentially output to the outside one pixel at a time.

The W signal of the next read line is accumulated in each pixel on the sensor array. When reading of the original for one line is completed, the image sensor unit 200
Further moves to the next reading line, the start pulse SP is input again, and the W signal already stored in each pixel on the sensor array is converted to an analog signal c on the sensor array.
After all the pixels are transferred at the same time, they are sequentially output to the outside one pixel at a time. By repeating such a series of operations while moving the image sensor unit 200 line by line in the sub-scanning direction, black and white reading of the entire document surface is performed.

Next, in step S1, when the mode is the color reading mode, the same light source control as that shown in FIG. 36 is performed. First, the process proceeds to step S8, and when reading the image of the first line, the process proceeds to step S9, where the signal φR
Only the R LED is turned on, and the start pulse SP,
The operation of the sensor array is started by the clock pulse CLK, and the R signal is accumulated in each pixel on the sensor array.
When the accumulation period tron12 of the R signal has passed, the LED of R is turned off by the signal φR, the LED of G is turned on by the signal φG in step S10, and the start pulse SP is input again, and each pixel on the sensor array is already turned on. The stored R signals are simultaneously transferred to the analog memory on the sensor array for all pixels, and are sequentially output to the outside one pixel at a time.

At this time, a G signal is simultaneously stored in each pixel on the sensor array. Then, the accumulation time tg of the G signal
After ON12, the LED of G is turned off by the signal φG, and the LED of B is turned on by the signal φB in step S11.
Lights up and the start pulse SP is input again,
The G signals already stored in each pixel on the sensor array are simultaneously transferred to the analog memory on the sensor array for all pixels, and then sequentially output to the outside one pixel at a time.

At this time, the B signal is simultaneously stored in each pixel on the sensor array. Then, the accumulation time tb of the B signal
When on12 has passed, the LED of B is turned off by the signal φB, and when reading the next line in step S12, the LED of R is output by the signal φR in step S13.
Lights up and the start pulse SP is input again,
The B signal already stored in each pixel on the sensor array is simultaneously transferred to an analog memory on the sensor array for all pixels, and then sequentially output to the outside one pixel at a time.

At this time, the image sensor unit 200 has moved to the next reading line, and the same R, G, B
An operation for obtaining a signal is performed. By repeating this series of operations while moving the image sensor unit 200 line by line in the sub-scanning direction, a color image on the entire document surface is read.

[0052] In this embodiment, the time period R LED is lit _{t ron1 = t ron12 / 3,} G LED is lit _{t gon1 = t gon12 / 3,} B LED is lit The relationship of time t _bon1 = t _bon12 / 3, and the LE of R
D only during the period _t ron12, LED only during the period t _Gon12 of G, the output of the line sensor of a predetermined level when irradiated with respective white reference period of the LED only t _Bon12 of B is adapted to obtain, R , G and B LEDs in sequence
_The same predetermined level of line sensor output can be obtained when the white reference is applied for each of the periods _ron1 , _tgon1 , and _tbon1 .

Therefore, the L of R, G, and B as shown in FIG.
If the lighting control of the ED is performed, one line of a monochrome document can be read within the same time as the reading time per color of one line in the color document reading mode, and the start pulse SP and the clock pulse CLK are used to read the color document. The output signal V of the image sensor
Out can be output at the same timing as in the color mode, and the signal processing circuit may be the same.

Further, each LED of R, G, B in FIG.
Is turned on / off in the color original reading mode without changing the lighting duty of each of the R, G, and B LEDs, and the lighting time is reduced to 1/3. Therefore, the lighting control pulses φR, φG, Generation of φB is also easy. Further, unlike the conventional black-and-white original reading mode shown in FIG. 37, the R, G, and B LEDs are not turned on at the same time.
The temperature rise of the D substrates 41 and 42 is small and the reliability is higher.

It should be noted that R, G, B in this embodiment described above.
In the driving method of the LED light source switching type color image sensor, the forward current is changed in the reading mode for both the color original and the monochrome original regardless of the relationship between the allowable value of the forward current and the duty of the LED shown in FIG. The advantage of no need remains. In addition, the reading time of a black-and-white document is exactly 1/3 that of reading a color document, and output signals can be taken out at the same timing as black and white and color, so that the same signal processing can be performed.

As described above, if the color image sensor unit is driven under the driving conditions of the present embodiment, the LED driving circuit, the sensor array driving circuit, and the signal processing circuit in the same color original reading mode can be used, and the reading of the monochrome original can be easily performed. Can be done.

(Second Embodiment) FIG. 12 is a diagram showing the operation timing of a second embodiment of the present invention. Similar to FIG. 8, the R, G, and B LEDs are turned on and off when reading a monochrome document. The timing of the output of the image sensor is shown.

Next, a light source control flowchart in this embodiment is shown in FIG. First, when the reading mode is input in step S1, the process proceeds to step S2 in the case of the monochrome reading mode, and in the case of reading the image of the first line, the process proceeds to step S21, where R is determined by the signals φR, φG, and φB. LED for tron1 period, G LED for tgon
The LED of B is simultaneously turned on for two periods and the tbon3 period, respectively. Also, a start pulse SP and a clock pulse C
The operation of the sensor array is started by LK, and a W signal corresponding to a monochrome image is accumulated in each pixel on the sensor array. When reading of the original for one line is completed, the image sensor unit 200 moves to the next reading line, and a start pulse SP is input again. In step S6, the W signal already accumulated in each pixel on the sensor array is output. After all the pixels are simultaneously transferred to the analog memory on the sensor array, they are sequentially transferred to the outside one pixel at a time.

In step S1, when the mode is the color reading mode, it is the same as that described with reference to FIG. In addition, tron1, tgon1,
tbon1 and tron12, tgon12, tbon1
The relationship of 2 is the same as that described in the first embodiment.

In the present embodiment, a monochrome image is reproduced from output signals of a plurality of line sensors obtained by turning on all the R, G, and B LEDs simultaneously during a monochrome original reading period for one line. . Any one of R, G, B in the color original reading mode shown in FIG.
The reading of one line of the black-and-white document is completed in the same time as when only the type of LED is lit. Therefore, the start pulse SP and the clock pulse CLK may be the same as in the color original reading mode, and the output signal Vout of the image sensor is output at the same timing as in the color mode, so that the signal processing circuit may be the same.

(Third Embodiment) FIGS. 14 and 15 show the outer shape and cross section of a light source switching type color image sensor 201 according to a third embodiment of the present invention.
The structure of the main part is the same as that of the color image sensor 200 shown in FIGS. 1 and 2. The frame 20 is a frame 70, the transparent glass plate 21 is a transparent glass plate 71, and the bottom plate 25.
Are changed to the bottom plate 75 and the light guide light source 3 is changed to the light guide light source 53.

FIGS. 16 and 17 show the shape and cross section of the image sensor of the light guide light source 53 in the longitudinal direction. LED substrates 43 and 44 are attached to the incident surfaces 54 at both ends. In the figure, 55 denotes LED chips 31 to 33
A light guide portion for transmitting the light emitted from the light guide in the longitudinal direction of the light guide light source 53, a reflecting portion 56 for diffusing and reflecting the incident light propagating through the light guiding portion 55 in the direction of the original, and a reflecting portion 57 This is a light condensing section for condensing the reflected light from the portion 56 to be read on the original. It should be noted that the rectangles shown by dotted lines in FIG. 3 indicate the positions of the LED chips 31 to 33 on the LED board 43.

FIG. 18 shows an arrangement of three types of LED chips 31 to 33 of R, G, and B on the LED board 43.
Two of each are directly mounted on the LED board 43.
As in the first embodiment, on and off of the LED chips 31 to 33 on the LED board 43 can be controlled to be turned on and off at independent timings for the R, G, and B light emission colors.

Although not shown, three types of LED chips 31 to 33 of R, G, and B are directly mounted on the LED board 44 just like the LED board 43. This L
The light emitted from the LED chips 31 to 33 on the ED substrates 43 and 44 irradiates only the vicinity of the original reading surface according to the same principle as in the first embodiment. Since the LED substrates 43 and 44 are mounted directly on the LED substrates 43 and 44 and the light guide light source 53
Are the LED substrates 41 and 42 in the first embodiment, respectively.
And the size is smaller than that of the light guide light source 3. In addition, the number of LED chips attached to the incident surface of one light guide light source is also increasing, so that the document surface can be illuminated more brightly and color reading can be performed at high speed.

Here, the LED chip used for illuminating the original in the color image sensor unit of this embodiment is as follows.
Due to manufacturing, it has a luminous intensity variation of the distribution shown in FIG.
It is necessary to illuminate the original corresponding to all the LED chips having about three times variation in luminous intensity. Therefore, as shown in FIG. 20, the lighting time of each LED chip is adjusted according to the luminous intensity of the LED chip so that a constant sensor output level can be obtained when the white reference is irradiated.

That is, the LE having the darkest relative luminous intensity of 0.5
When the D chip is incorporated in the image sensor unit, the LED is used for the entire reading time of one line.
Is turned on so that a predetermined sensor output level is obtained. For an LED chip that is brighter than the LED chip, a portion L that is brighter than an LED chip having a relative luminous intensity of 0.5 is used.
This is to shorten a lighting time of the ED only to obtain a predetermined sensor output level.

As described above, the driving of the light source switching type color image sensor in this embodiment is controlled by the image sensor driving circuit 101 shown in FIG. 35 similarly to the first embodiment, and the control signals φR, φG, φB
And SP and CLK are output to the light source switching type image sensor unit 201, and the following reading is performed by such a control signal.

First, R, G,
The B LED is turned on for each emission color, and the lighting times t _ron19 , t _gon19 , and t _gon19 of each emission color are obtained so that a predetermined level of sensor output is obtained when the white reference is irradiated as described above.
_{Determine bon19} .

Next, the actual reading of the original is performed in the same procedure as in the first embodiment as shown in FIGS. In the color reading mode, in step S31, R
_Are turned on for a predetermined period of time _tron19 determined when only the first LED irradiates the white reference and then turned off. At the same time, the operation of the sensor array is started by the start pulse SP and the clock pulse CLK, and the R signal is accumulated in each pixel on the sensor array. R, G, B color signals accumulation time (signal reading _{time) t r19, t g19, t} b19 darkest LE
Determined according to D chip, usually R LED
Even after the chip is turned off, the G LED chip does not turn on immediately.

Then, after the predetermined R signal accumulation time has elapsed, the G LED is turned on in step S32, and the start pulse SP is input again, and the R signal already accumulated in each pixel on the sensor array is transmitted to the sensor array. After all the pixels are simultaneously transferred to the upper analog memory, they are sequentially output to the outside one pixel at a time. At this time, a G signal is simultaneously stored in each pixel on the sensor array.

Then, the LED for the period G of the predetermined time _tgon19 determined when the white reference is first irradiated is turned on and then turned off. The signal storage time of this G is also the darkest L, like the R.
It is determined in advance corresponding to the ED chip, and the LED of B does not turn on until the predetermined time has elapsed. In step S33, when the G signal accumulation time is over, the B LED is turned on, and the start pulse SP is input again, and the G pulse already accumulated in each pixel on the sensor array.
After the signals are simultaneously transferred to the analog memory on the sensor array for all the pixels, the signals are sequentially output to the outside one pixel at a time.
At this time, the B signal is simultaneously accumulated in each pixel on the sensor array.

Then, the LED for the period B of the predetermined time _tbon19 determined when the white reference is first irradiated is turned on and then turned off. The signal storage time of B is also predetermined in correspondence with the darkest LED chip similarly to R and G, and the LED of R does not turn on until the predetermined time has elapsed. When the signal accumulation time of B ends, the image sensor unit 201 moves to the next reading line, and in step S34, the LED of R lights up and the start pulse SP is input again, and the image is already accumulated in each pixel on the sensor array. After the transferred B signal is simultaneously transferred to the analog memory on the sensor array for all pixels, it is sequentially output to the outside one pixel at a time. At this time, the R signal on the next read line is simultaneously accumulated in each pixel on the sensor array.

By repeating such a series of operations while moving the image sensor unit 200 line by line in the sub-scanning direction, color reading corresponding to all LED chips having a predetermined luminous intensity distribution can be performed on the entire original surface. Done over.

Next, in the monochrome original reading mode, control signals φR, φG, φB and SP, CLK as shown in FIG. 18 are output from the image sensor driving circuit 101 to the light source switching type image sensor unit 201. The following reading is performed by such a control signal.

First, before reading the original, R, G,
The B LED is turned on for each emission color, and when the white reference is illuminated, each of the LEDs is set to 1/1 / the setting level in the color original reading mode.
Third output level lighting time of each light emitting color of the LED so as to obtain from the line sensor _{t ro n20, t gon20, t} bon20
To determine. Then, as shown in FIG. 22, the R, G, and B LEDs are sequentially _{turned on} during the time for reading one line of one color in the color original reading mode.
_gon20, t _bon20 simply to obtain a line sensor output of the same predetermined level as in the color reading mode on. As described above, when the lighting time of each of the R, G, and B LEDs is determined, t _ron20 = t _ron19 / 3, t _gon20 = t
_gon19 / 3, _tbon20 = _tbon19 / 3, and each L in the monochrome reading mode and the color reading mode
The ratio of the lighting time of the ED is 1: 3 as in the first embodiment.

After the lighting time of each of the R, G, and B LEDs is determined as described above, the actual reading of the original is started at the timing shown in FIG.
The operation of the sensor array is started by K, and in steps S35, S36, and S37 in FIG. 23, the three types of LEDs of R, G, and B are sequentially set to t _ron20 , within one line reading time.
After turning on only for the period of t _gon20 and t _bon20, the light turns off, and each pixel on the sensor array has W corresponding to a monochrome image.
The signal is accumulated. Then, the signal accumulation time t _w20 of as in the first embodiment W is darkest R, G, are predetermined in correspondence with the case of the color original reading with the LED chips of B, t _w20 = t _{g1 9} = t _g19 = t
_{It is b19} .

After the _lapse of the predetermined time t _w20 , the image sensor unit 201 moves to the next reading line, and the start pulse SP is input again, and step S6 is performed.
, The W signal of the previous read line already stored in each pixel on the sensor array is simultaneously transferred to the analog memory on the sensor array for all pixels, and then sequentially output to the outside one pixel at a time. At this time, as in the case of the previous line, the three types of LEs of R, G and B are set within one line reading time.
D sequentially turns on only for the periods of t _ron20 , t _gon20 , and t _bon20 , then turns off, and the W signal of the next read line is accumulated in each pixel on the sensor array. By repeating such a series of operations while moving the image sensor unit 201 one line at a time in the sub-scanning direction, color image reading corresponding to all LED chips having a predetermined luminous intensity distribution is performed over the entire original surface. Will be

As described above, by driving the color image sensor at the timing shown in FIG. 22, even when all the LED chips having luminous intensity variation are dimmed and used, the reading time of exactly 1/3 of the color original is obtained. Can read a black-and-white original and output signals can be taken out at the same timing as black and white and color, so that the same signal processing can be performed. Therefore, a color image sensor unit and one type of LED
The driving circuit, the sensor array driving circuit, and the signal processing circuit can easily read a black-and-white original.

(Fourth Embodiment) FIG. 24 is a diagram showing the operation timing of the fourth embodiment of the present invention. As in FIG. 12, the R, G, and B LEDs are turned on and off when reading a monochrome document. The timing of the output of the image sensor is shown. FIG. 25 is an operation flowchart.

In this embodiment, as in the second embodiment, the R, G, and B L, G, B
A monochrome image is reproduced from output signals of a plurality of line sensors obtained by lighting all the EDs.

That is, first, before the actual document reading, the R, G, B L
The ED is turned on for each emission color, and the LED of each emission color is obtained so that a predetermined sensor output level is obtained when the white reference is irradiated.
Of lighting time _t ron20, to determine the _t gon2 _0, t bon20.
In the black-and-white original reading mode, three kinds of LEDs are turned on at the same time, so that the sensor output level obtained when the R, G, and B LEDs are individually turned on and the white reference is irradiated is reduced to one third of that in the color original reading mode. Set. Therefore, t
_ron20 = t _ron19 / 3, t _gon20 = t _gon19 / 3, t
_bon20 = _tbon19 / 3.

Next, in step S41 of FIG.
All three types of LEDs, R, G, B, are turned on and
Sensor by start pulse SP and clock pulse CLK
Array operation begins and each pixel on the sensor array is white
A W signal corresponding to a black image is accumulated. R, G, B 3
LED of each type is set at the time of reading the white reference described above.
LED lighting time t_ron20 , T_gon20 , T_bon20 Period of
After being turned on, they are turned off at individual timings. W
Signal accumulation time t_w20 Uses the darkest LED chip
Determined in advance when scanning color documents
And t _w20 = T_g19 = T_g19 = T_b19 In
You.

Until the above-mentioned predetermined time t _{w20 elapses} , R,
The G and B LEDs do not light. After the signal accumulation time _{tw20 of} W has passed, the image sensor unit 201
Moves to the next reading line, all the R, G, and B LEDs are turned on again, and the start pulse SP is input. In step S6, the W of the previous reading line already accumulated in each pixel on the sensor array is read. After the signal is transferred to the analog memory on the sensor array for all pixels simultaneously,
It is sequentially output to the outside one pixel at a time. At this time, each pixel on the sensor array simultaneously has W on the next read line.
The signal is accumulated.

By repeating such a series of operations while moving the image sensor unit 201 line by line in the sub-scanning direction, color reading corresponding to all LED chips having a predetermined luminous intensity distribution can be performed on the entire original surface. Done over. The same operation and effect as those of the above-described embodiments can be obtained by such control.

(Fifth Embodiment) As shown in FIG. 26, the image sensor of this embodiment comprises a plurality of sensor ICs 301 each having a linear photoelectric conversion element group, corresponding to the length of a read document. , A lens array 303, an illuminating device 304, a cover glass 305 made of a light transmitting member for supporting a document, and positioning and holding these components. The frame 306 is made of a metal such as aluminum or a resin material such as polycarbonate.

The respective functions are as follows. The illumination device 304 sequentially illuminates the color original supported by the cover glass 305 by switching the three colors of light of R, G, and B from an oblique direction, and sequentially illuminates the R, G, and B of the original. The three-color optical information is imaged on the sensor IC 301 by the lens array 303, and the sensor IC 301 converts the three-color optical information of R, G, and B into an electric signal and transmits the electric signal to the system, where R, G, and B are transmitted. The three color electric signals are processed to reproduce a color image.

Even when a monochrome document is read by the color document reading image sensor, that is, when a monochrome document is read instead of a color document, it is treated as signals of three colors of R, G, and B. Therefore, it takes a long time to read. An error due to a reading error may occur. In particular, in the case of reading a black and white document existing between color document readings, a black and white document is read as a color document, so that waste occurs.

Therefore, in this embodiment, when reading a black and white original instead of a color original, the original reading speed is not changed, and the luminance of each color of R, G, and B for one line to be read is supplied to each light source by the amount of power supplied to each light source. Is controlled to prevent the luminance of the light source from deteriorating. FIG.
Reference numerals 7 and 28 denote operation timings in the color reading mode and the monochrome reading mode in this embodiment, respectively.

That is, in FIG. 26, variable luminance limiting resistors 310, 31
1, 312 are provided, and a light source to be irradiated is switched by a switch 315 to sequentially illuminate. When reading a black-and-white document existing between color document readings, the resistance of each resistor is increased to limit the luminance, thereby preventing a decrease in illuminance due to deterioration of the light source and enabling a longer life of the image sensor. . Further, it is possible to improve the quality reliability of the entire apparatus without changing the balance of each color of the illumination device in conversion from a black-and-white document to a color document.

FIG. 29 is a flowchart showing the light source control operation of this embodiment. If the mode is the monochrome reading mode in step S51, the process proceeds to step S52 to limit the power supplied to each LED by increasing the resistance values of the resistors 310, 311 and 312. Note that the resistance values of the respective resistors are set separately, and it is not necessary to increase all the resistance values. Then, in step S53, the monochrome image is read, and the operation ends.

If the mode is the color reading mode in step S51, a color image is read in step S54.
End the operation.

(Sixth Embodiment) A sixth embodiment of the present invention will be described with reference to FIGS. 30, 31, and 32. FIG.

The operation timing chart in the color reading mode is the same as that in FIG. 27 described above.

In this embodiment, when a monochrome original is read by the color original reading image sensor, the original reading speed is changed to be faster than that during the color reading, and the illumination time of the three colors R, G, and B is applied to one read line. , The luminance of the light source is prevented from deteriorating.

In FIG. 30, a roller 3 for conveying a document
The rotation speed of 20 is rotated at a high speed three times the color reading mode, and the sensor driving cycle is also changed at a high speed three times. Then, the three color light sources of R, G, and B are switched to sequentially illuminate, and the electric signal photoelectrically converted by the sensor IC is subjected to signal processing for reading a monochrome document. By switching at the time of reading, the lighting time of the light source is reduced to, for example, one third of that at the time of color reading, whereby illuminance reduction due to light deterioration of the light source is prevented, and the life of the image sensor can be prolonged. It is possible to improve the quality reliability of the entire device without changing the balance of each color of the illumination device in the conversion from the color document to the color document. FIG. 31 shows the operation timing.

FIG. 32 is an operation flowchart of this embodiment. If the mode is the monochrome reading mode in step S61, the flow advances to step S62 to set the document conveying speed to 3
And the sensor drive cycle is set to three times, and the lighting time of each light source is set to one third. Then, in step S63, the monochrome image is read, and the operation ends. If the mode is the color reading mode, color image reading is executed in step S64.

(Seventh Embodiment) A seventh embodiment of the present invention will be described with reference to FIGS. 30, 33 and 34.

In this embodiment, when a monochrome original is read by the color original reading image sensor, the original transport rollers 3
20 is rotated at a speed three times as high as that during color reading, but the sensor driving cycle is not changed, and instead of turning on all light sources of R, G, and B for one reading line, the reading line By illuminating a document image with a light source of one or two colors each time, the total illumination time of each light source is reduced, thereby preventing luminance degradation of the light sources.

Further, the light sources to be turned on are sequentially switched and illuminated for each reading line, thereby preventing variations in luminance of the R, G and B light sources.

In FIG. 33, the light sources of the three colors of R, G, and B are switched for each reading line, sequentially switched and illuminated, and the photoelectric conversion signal for each line is corrected to perform processing.
By switching to this control when reading a black-and-white document that exists between color document readings, it is possible to prevent illuminance reduction due to light deterioration of the light source, to extend the life of the image sensor, and to switch from a black-and-white document to a color document. It is possible to improve the quality reliability of the entire device without changing the balance of each color of the lighting device in the conversion.

FIG. 34 is an operation flowchart of this embodiment. If the mode is the monochrome reading mode in step S71, the process proceeds to step S72. When reading the first line, the R LED is turned on in step S73, and step S7 is performed.
4. Read the image. If the next line is to be read in step S75, the G LED is turned on in step S76, and an image is read in step S77. If the next line is to be read in step S78, the process advances to step S79 to turn on the LED of B, and the image is read in step S80. As described above, in the present embodiment, the light sources that are turned on for each line to be read are sequentially switched in the order of R, G, and B. However, the order is not limited to this. Alternatively, a different light source may be turned on for each line.

As described in the first to fourth embodiments, when reading a black-and-white document using a light source switching type color image sensor, the lighting duty of each light-emitting element is set to be the same as when reading a color document, and By reducing the lighting time to one-third and lighting them sequentially or all, the forward current of each light-emitting element can be made the same in both the color original reading mode and the black-and-white original reading mode. There is an effect that there is no need to provide

Further, since the signal accumulation time or sensor output time for one line when reading a monochrome original can be made the same as the signal accumulation time or sensor output time for one color when reading a color original, a signal processing circuit is also required. In particular, it is not necessary to add a reading device for reading a black-and-white document or to provide an adjusting unit. The illuminating device is composed of three light sources such as three LEDs of R, G, and B, and the number of parts of the entire device of the switchable color image sensor can be greatly reduced by switching the light sources.

In the color image sensor of the illumination switching type configuration, when reading a monochrome original from reading a color original as in the fifth to seventh embodiments, the illuminating device may be a light source such as an LED of each color of R, G, B. Lighting with reduced brightness, speeding up the document reading speed with the same brightness as when reading color documents, or time-division lighting for each color for each document reading line can reduce the light source lighting time when reading monochrome documents. It is possible to reduce the illuminance due to the deterioration of the light source, to prolong the life of the image sensor, and not to change the balance of each color of the illuminating device in conversion from a black-and-white document to a color document. Quality reliability can be improved.

[0105]

As described above, according to the present invention, when performing color reading and monochrome reading, it is possible to read an image with an appropriate amount of light, to prevent a decrease in illuminance due to deterioration of the light source, The service life can be extended.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a light source switching type color image sensor.

FIG. 2 is a sectional view showing the internal structure of a light source switching type color image sensor.

FIG. 3 is a configuration diagram of a substrate on which a sensor array is mounted.

FIG. 4 is a side view of the light guide light source.

FIG. 5 is a sectional view of a light guide light source.

FIG. 6 is a diagram showing an example of the arrangement of LED packages and LED chips on an LED substrate.

FIG. 7 is a configuration block diagram of an image reading system.

FIG. 8 is an operation timing chart at the time of reading a black-and-white document in the first embodiment.

FIG. 9 is a characteristic diagram showing a relationship between an allowable forward current of an LED and a duty ratio.

FIG. 10 is a diagram showing a relationship between forward current and relative luminous intensity of an LED.

FIG. 11 is a flowchart illustrating an original reading operation in the first embodiment.

FIG. 12 is an operation timing chart at the time of reading a black and white original in the second embodiment.

FIG. 13 is a flowchart illustrating a document reading operation according to the second embodiment.

FIG. 14 is a perspective view illustrating an appearance of a color image sensor according to a third embodiment.

FIG. 15 is a sectional view showing the internal structure of a color image sensor according to a third embodiment.

FIG. 16 is a configuration diagram of a substrate on which a sensor array is mounted.

FIG. 17 is a sectional view of a substrate on which a sensor array is mounted.

FIG. 18 is a diagram showing an example of the arrangement of LED chips on a substrate.

FIG. 19 is a diagram showing a distribution of relative luminous intensity of an LED chip.

FIG. 20 is a diagram illustrating a state where the lighting time of an LED is changed in the third embodiment.

FIG. 21 is a diagram illustrating lighting timings of LEDs when reading a color original in the third embodiment.

FIG. 22 is a diagram showing lighting timings of LEDs when reading a black-and-white document in the third embodiment.

FIG. 23 is a flowchart illustrating a document reading operation according to the third embodiment.

FIG. 24 is an operation timing chart when a monochrome image is read in the fourth embodiment.

FIG. 25 is a flowchart illustrating a document reading operation according to the fourth embodiment.

FIG. 26 is a cross-sectional view illustrating a configuration of an image sensor according to a fifth embodiment.

FIG. 27 is an operation timing chart during color reading.

FIG. 28 is an operation timing chart in the fifth embodiment.

FIG. 29 is a flowchart illustrating a document reading operation according to the fifth embodiment.

FIG. 30 is a cross-sectional view illustrating a configuration of an image sensor according to a sixth embodiment.

FIG. 31 is an operation timing chart in the sixth embodiment.

FIG. 32 is a flowchart showing a document reading operation in the sixth embodiment.

FIG. 33 is an operation timing chart in the seventh embodiment.

FIG. 34 is a flowchart showing an original reading operation in the seventh embodiment.

FIG. 35 is a block diagram showing a configuration of a drive circuit of a light source switching type color image sensor.

FIG. 36 is a diagram illustrating lighting timing of each LED when reading a color original.

FIG. 37 is a diagram showing lighting timing of each LED when reading a black and white original.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sensor array 2 Line sensor 3 Light guide light source 31 LED chip 32 LED chip 33 LED chip 53 Light guide light source 101 Image sensor drive circuit 104 LED lighting control unit 105 Sensor array drive unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C051 AA01 BA02 DA03 DB01 DB22 DB29 DB31 DC05 DE29 EA01 EA09 5C072 AA01 BA02 BA03 CA05 CA07 CA12 CA14 DA02 EA07 FB15 QA12

Claims (47)

[Claims] A plurality of light sources having mutually different emission wavelengths; photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light source; switching means for switching between a first mode and a second mode; In both the case where the first mode is selected by the switching unit and the case where the second mode is selected by the switching unit, the photoelectric conversion unit is controlled to read out the signal accumulated in the first line period. Reading control means, in the first mode, supplying a lighting control signal so as to sequentially light each of the plurality of light sources for each of the first line periods, and in the second mode, Lighting control means for supplying a lighting control signal so as to sequentially light the plurality of light sources during a line period, wherein the lighting control means includes a first mode. The duty ratio of the lighting control signal for lighting the plurality of light sources is not changed between the mode and the second mode, and the lighting time of the second mode is set to be the same for each light source as compared with the lighting time of the first mode. An image reading device characterized in that the image reading device is changed so as to shorten the image reading device. 2. The image reading apparatus according to claim 1, wherein a lighting order of the plurality of light sources by the lighting control unit is the same in the first mode and the second mode. 3. A plurality of light sources are sequentially turned on to irradiate a white reference before reading a document in the second mode.
2. The image processing apparatus according to claim 1, further comprising a determination unit configured to determine a sequential lighting period of each light source that is lit within the first line period in the second mode in accordance with an output signal from the photoelectric conversion unit. Alternatively, the image reading device according to claim 2. 4. The lighting control of each of the light sources by the lighting control means, wherein a lighting current of each of the light sources is not changed between the first mode and the second mode. An image reading device according to claim 1. 5. The readout unit outputs an output clock pulse for sequentially outputting a signal for each pixel from the photoelectric conversion unit within the first line period in the first mode and the second mode. The image reading device according to claim 1, wherein the image reading device is the same. 6. A plurality of light sources having different light and darkness, photoelectric conversion means for photoelectrically converting a subject image illuminated by the light source, switching means for switching between a first mode and a second mode, and switching means Lighting control means for sequentially lighting the plurality of light sources, both when the first mode is selected and when the second mode is selected by the switching means; and in the first mode, the lighting mode The signals accumulated by the photoelectric conversion means are sequentially read out in the first line period in response to the lighting of each light source by the control means, and the second mode corresponds to the lighting of a plurality of light sources by the lighting control means. The control is performed such that the signals added and accumulated by the photoelectric conversion means are read out in the first line period once each time a plurality of light sources are sequentially turned on. Image reading apparatus characterized by comprising: a read control means for the period corresponding to the lighting time in the first mode of the darkest light source of the first line period of the plurality of light sources, a. 7. The read control unit outputs an output clock pulse for sequentially outputting a signal for each pixel from the photoelectric conversion unit during the first line period according to the first mode and the second mode. 7. The image reading device according to claim 6, wherein 8. The image reading apparatus according to claim 6, wherein a lighting order of the plurality of light sources by the lighting control unit is the same in the first mode and the second mode. . 9. In the second mode, before reading an original, the plurality of light sources are sequentially turned on to emit a white reference,
7. The image processing apparatus according to claim 6, further comprising: a determination unit configured to determine a sequential lighting period of each light source that is lit within the first line period in the second mode according to an output signal from the photoelectric conversion unit. 9. The image reading device according to any one of claims 1 to 8. 10. The image reading apparatus according to claim 9, wherein a ratio of a lighting period between the light sources by the lighting control unit is the same in the first mode and the second mode. . 11. The light emitting device according to claim 6, wherein a lighting duty ratio of each light source by the lighting control means is the same in the first mode and the second mode. Image reading device. 12. The lighting control of each of the light sources by the lighting control means, wherein the lighting current of each of the light sources is controlled by the first current.
The image reading apparatus according to claim 11, wherein the same mode is set in the second mode and the second mode. 13. A method for controlling an image reading apparatus, comprising: a plurality of light sources having different emission wavelengths from each other; and a photoelectric conversion unit configured to photoelectrically convert a subject image illuminated by the light sources. A switching step of switching between the first mode and the second mode by the photoelectric conversion means in both the case where the first mode is selected in the switching step and the case where the second mode is selected in the switching means. A read control step of controlling to read a signal accumulated in a period, and in the first mode, a lighting control signal is supplied so as to sequentially light the plurality of light sources in each of the first line periods, In the second mode, a lighting control signal is provided so that the plurality of light sources are sequentially turned on within the first line period. A lighting control step of turning on the plurality of light sources in the first mode and the second mode without changing a duty ratio of a lighting control signal for lighting the plurality of light sources. A control method characterized by changing the lighting time of the second mode to be shorter at the same rate for each light source than the lighting time. 14. The control method according to claim 13, wherein, in the lighting control step, a lighting order of the plurality of light sources is the same in the first mode and the second mode. 15. The method according to claim 15, wherein the plurality of light sources are sequentially turned on to irradiate a white reference before reading an original in the second mode, and the second light source is illuminated in the second mode in accordance with an output signal from the photoelectric conversion means. 15. The control method according to claim 14, further comprising a determining step of determining a sequential lighting period of each light source that is lit in the first line period. 16. The control method according to claim 15, wherein the lighting current of each light source is not changed between the first mode and the second mode when each of the light sources is turned on. 17. The read-out means according to claim 1, wherein said read-out means outputs an output clock pulse for sequentially outputting a signal for each pixel from said photoelectric conversion means during said first line period in said first mode and said second mode. 17. The control method according to claim 13, wherein the control method is the same. 18. A method for controlling an image reading apparatus, comprising: a plurality of light sources having different brightnesses; and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources, the method comprising: a first mode and a second mode. And a lighting control step of sequentially lighting the plurality of light sources in both the case where the first mode is selected in the switching step and the case where the second mode is selected in the switching step. In the first mode, the signals accumulated by the photoelectric conversion means are sequentially read out in the first line period in correspondence with the lighting of each light source in the lighting control step, and in the second mode, Sequentially lighting the plurality of light sources by adding the signals accumulated by the photoelectric conversion means in response to the lighting of the plurality of light sources by the lighting control means. The first line period is controlled so as to be read once every time, and the first line period is a period corresponding to the lighting time of the darkest light source of the plurality of light sources in the first mode. And a read control step. 19. The read control step, comprising: outputting an output clock pulse for sequentially outputting a signal for each pixel from the photoelectric conversion means during the first line period in the first mode and the second mode. 19. The control method according to claim 18, wherein 20. The control method according to claim 18, wherein a lighting order of the plurality of light sources by the lighting control unit is the same in the first mode and the second mode. 21. In the lighting control step, before reading a document in the second mode, the plurality of light sources are sequentially turned on to irradiate a white reference, and in accordance with an output signal from the photoelectric conversion means, 21. The control method according to claim 18, further comprising a determining step of determining a sequential lighting period of each light source that is lit within the first line period in the second mode. 22. The lighting control step, wherein the ratio of the lighting period between the light sources is determined by comparing the first mode with the second mode.
22. The control method according to claim 21, wherein the control mode is the same in both modes. 23. The lighting control step, wherein a lighting duty ratio of each light source is the same in the first mode and the second mode.
23. The control method according to any one of claims 22 to 22. 24. The lighting control of each of the light sources in the lighting control step, wherein the lighting current of each of the light sources is the same in the first mode and the second mode. 24. The control method according to 23. 25. A storage medium storing a computer-readable program that can execute the control method according to claim 13 in an image reading apparatus. 26. An image reading device having a plurality of light sources having different emission wavelengths from each other and a photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources, and an image reading device connectable to a control device via an interface. A memory storing a light source control program corresponding to a first mode and a light source control program corresponding to a second mode for performing light source lighting control different from the first mode; And reading out a program corresponding to each of the case where the first mode is selected and the case where the second mode is selected from the memory, and according to the read-out program, according to the mode via the interface. Lighting control means for controlling lighting of the plurality of light sources. Image reading system. 27. The image reading system according to claim 26, wherein the plurality of light sources are sequentially turned on in both the first mode and the second mode. 28. In both the first mode and the second mode, the plurality of light sources are sequentially turned on such that the lighting periods of the plurality of light sources do not overlap.
An image reading system according to claim 1. 29. In the first mode, signals accumulated by the photoelectric conversion means corresponding to lighting of each light source are sequentially read out in a first line period, and in the second mode, the plurality of light sources are read. 29. The signal according to claim 26, wherein the signal added and accumulated by the photoelectric conversion means is read out once in each of the plurality of light sources in the first line period in correspondence with the lighting of the light source. Image reading system. 30. A control device connectable via an interface to an image reading device having a plurality of light sources having mutually different emission wavelengths and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources. A memory storing a light source control program corresponding to the first mode and a light source control program corresponding to a second mode for performing light source lighting control different from the first mode; and selecting the first mode. And reading the programs corresponding to the respective cases when the second mode is selected from the memory and controlling the lighting of the plurality of light sources according to the mode via the interface according to the read programs. A control device, comprising: control means. 31. The control device according to claim 26, wherein the plurality of light sources are sequentially turned on in both the first mode and the second mode. 32. In both the first mode and the second mode, the plurality of light sources are sequentially turned on such that the lighting periods of the plurality of light sources do not overlap.
The control device according to claim 1. 33. In the first mode, signals accumulated by the photoelectric conversion means corresponding to lighting of each light source are sequentially read out in a first line period, and in the second mode, the plurality of light sources are read. 33. The signal according to claim 30, wherein a signal added and accumulated by the photoelectric conversion means is read out once in each of the plurality of light sources in the first line period in response to lighting of the light source. Control device. 34. An image reading apparatus comprising: a plurality of light sources having mutually different emission wavelengths; photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources; and an interface connectable to a control device. A plurality of light sources, receiving means for receiving an instruction of the control device based on a program corresponding to each of a case where a first reading mode is selected and a case where a second reading mode is selected; Therefore, an image reading apparatus having lighting means for performing lighting control. 35. The image reading apparatus according to claim 34, wherein the plurality of light sources are sequentially turned on in both the first mode and the second mode. 36. In both the first mode and the second mode, the plurality of light sources are sequentially turned on such that the lighting periods of the plurality of light sources do not overlap.
An image reading device according to claim 1. 37. In the first mode, signals accumulated by the photoelectric conversion means corresponding to lighting of each light source are sequentially read out in a first line period, and in the second mode, the plurality of light sources are read. 37. The signal according to any one of claims 34 to 36, wherein a signal added and accumulated by said photoelectric conversion means is read out in said first line period once each time a plurality of light sources are sequentially turned on in response to lighting of. Image reading device. 38. A control method of a control device connectable via an interface to an image reading device having a plurality of light sources having different emission wavelengths from each other and photoelectric conversion means for performing photoelectric conversion of a subject image illuminated by the light sources. A program corresponding to each of a case where the first reading mode is selected and a case where the second reading mode in which the light source lighting control is different from the first mode is selected from the memory in the control device. A control method, comprising: a reading step to read; and a lighting control step of performing lighting control of the plurality of light sources according to the mode via the interface according to the read program. 39. The control method according to claim 38, wherein the plurality of light sources are sequentially turned on in both the first mode and the second mode. 40. In both the first mode and the second mode, the plurality of light sources are sequentially turned on such that the lighting periods of the plurality of light sources do not overlap.
The control method described in 1. 41. In the first mode, signals accumulated by the photoelectric conversion means corresponding to lighting of each light source are sequentially read out in a first line period, and in the second mode, the plurality of light sources are read. 41. The signal according to any one of claims 38 to 40, wherein a signal added and accumulated by said photoelectric conversion means is read out in said first line period once each time a plurality of light sources are sequentially turned on in response to lighting of. Control method. 42. A storage medium storing a computer-readable program capable of executing the control method according to claim 38 in a control device. 43. A method for controlling an image reading apparatus, comprising: a plurality of light sources having different emission wavelengths from each other; photoelectric conversion means for photoelectrically converting a subject image illuminated by the light sources; and an interface connectable to a control device. A receiving step of receiving an instruction of the control device based on a program corresponding to each of a case where the first reading mode is selected and a case where the second reading mode is selected; A lighting step in which lighting control is performed according to the instruction. 44. The control method according to claim 43, wherein the plurality of light sources are sequentially turned on in both the first mode and the second mode. 45. In both the first mode and the second mode, the plurality of light sources are sequentially turned on such that the lighting periods of the plurality of light sources do not overlap.
The control method described in 1. 46. In the first mode, signals accumulated by the photoelectric conversion means corresponding to lighting of each light source are sequentially read out in a first line period, and in the second mode, the plurality of light sources are read. 46. The signal according to claim 43, wherein the signal added and accumulated by said photoelectric conversion means is read out once in each of the plurality of light sources in the first line period in correspondence with the lighting of. Control method. 47. A storage medium storing a computer readable program capable of executing the control method according to claim 43 in an image reading apparatus.