JP2002368955A - Image reader, light source abnormality processing method, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly handle light source illumination abnormality occurring when an image is read by using composite light obtained by turning on light sources of different colors. SOLUTION: When the light emission bodies which emit light beams of mutually different colors emit the light beams at the same time, respective reference values to be detected by a plurality of detecting means which receive the light beams emitted by the light emission bodies respectively and individually detect the quantities of photodetection are determined according to a specific ratio of the light emission quantities of the light emission bodies and the photodetection quantities detected by the detecting means are compared with the determined reference values (S4); if one photodetection quantity is different from the reference value corresponding to the photodetection quantity, it is decided (S8) that the light emission body corresponding to the photodetection quantity is abnormal and the image reading operation of the image reader is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device, a light source abnormality processing method, a program, and a storage medium, and more particularly, to a light source for irradiating a predetermined image reading surface and receiving light reflected from the image reading surface. An image reading apparatus having photoelectric conversion means for converting the light signal into an electric signal, a light source abnormality processing method applied to the image reading apparatus, a program for causing a computer to execute the light source abnormality processing method, and the program stored therein. It relates to a storage medium.

[0002]

2. Description of the Related Art In recent years, there has been a demand to reduce the size and weight of a scanner device for inputting an image to a personal computer and an image reading device constituting a facsimile device. Developed and put into practical use.

A contact type image sensor includes a rod lens for realizing an equal-length erect optical image extending in the main scanning direction of a document to be read, a one-dimensional light receiving sensor having an effective width equal to the main scanning width of the document to be read. It consists of. this is,
The optical path length of the optical system can be made shorter than that of an image sensor that reads the original image of the original to be read using a reduction optical system lens by reducing the main scanning width by a factor of several, using a one-dimensional CCD sensor or the like. Another feature is that the image reading apparatus can be reduced in size and weight.

In the above-described scanner and image reading apparatus, a cold cathode tube and a light emitting diode LED are used as light sources.
(Light Emitting Diode) and the like. Particularly, regarding the LED light source, in recent years, LEDs of each color of R (red), G (green), and B (blue) have been increased in brightness, and accordingly, LEDs of these colors have been added. Are simultaneously turned on to obtain white light to read a color image.

In a color image reading apparatus using an LED light source, as described above, R (red), G (green), and B (blue)
The LED light sources of the colors are simultaneously turned on to obtain white light, the white light is applied to the original, read signals corresponding to each color are obtained, and these read signals are used as color image signals. . In order to obtain white light, LE of each color is used.
Adjustment control of the light amount of the D light source is performed (for example, JP-A-6-334817, JP-A-11-34).
1221).

In a monochrome image reading apparatus using an LED light source, a manuscript is often read by performing monochromatic light emission using a single color (one color) LED light source. However, if the reading speed is to be increased, the amount of light is insufficient. Therefore, an image is read by using LED light sources of a plurality of colors (for example, three colors of R, G, and B), and lighting these at the same time.

[0007]

However, in the color image reading apparatus using the above-mentioned conventional LED light source, the relative ratio of the respective light amounts of the three color LED light sources is determined by determining the combined light of the LED light sources and the white light. Must always be maintained at a certain ratio, but if for any reason the ratio fluctuates,
There is a problem that the image of the color document cannot be read normally.

Further, when such a change in the ratio occurs, if the occurrence can be automatically detected by any method and the operation of the image reading apparatus can be stopped, the user can uselessly operate the image reading apparatus. However, even if such a method is realized, this method is not necessarily a preferable solution in a monochrome image reading apparatus of a type in which LED light sources of a plurality of colors are simultaneously turned on.
That is, in the case of a monochrome image reading device, there are many cases where reading does not hinder even if the above ratio fluctuates,
Nevertheless, if the operation of the image reading apparatus is automatically stopped, it does not benefit the user. In addition,
The same can be said for a monochrome image read by a color image reading apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above problems, and has been described in connection with light source lighting which occurs when an image is read using a combined light obtained by simultaneously lighting a plurality of light sources of different colors. It is an object of the present invention to provide an image reading apparatus, a light source abnormality processing method, a program, and a storage medium that appropriately deal with abnormalities.

[0010]

According to the first aspect of the present invention, there is provided a light source for irradiating a predetermined image reading surface, and a light source for receiving light reflected from the image reading surface. In an image reading apparatus provided with photoelectric conversion means for converting a signal, a plurality of light-emitting members that constitute the light source and emit light of different colors when current is supplied to each of the light-emitting members, Current supply means for supplying a predetermined amount of current over a predetermined time, and the predetermined time and location based on a predetermined ratio of the amount of light to be emitted when each of the plurality of light emitters emits light simultaneously. First determining means for determining at least one of the quantifications, and a plurality of detecting means constituting the photoelectric conversion means, each of which receives light emitted by the plurality of light emitters and individually detects the amount of received light; , The compound A second determination unit that determines each reference value to be detected by the plurality of detection units when each of the luminous bodies emits light at the same time based on a predetermined ratio of the light emission amount; Comparing means for comparing each of the received light amounts thus obtained with each of the reference values determined by the second determining means. As a result of the comparison by the comparing means, one of the plurality of received light amounts and the one received light amount are compared. An image reading apparatus comprising: a stop unit that determines that an abnormality has occurred in a light emitter corresponding to the one light reception amount and stops an image reading operation when the corresponding reference value is different from the reference value. Is provided.

According to the present invention, a light source for irradiating a predetermined image reading surface, a photoelectric conversion means for receiving light reflected from the image reading surface and converting the reflected light into an electric signal, A plurality of light-emitting members each configured to be supplied with a current and emit light of a different color from each other, and current supply means for supplying a predetermined amount of current to each of the plurality of light-emitting members for a predetermined time, A light source abnormality processing method applied to an image reading apparatus comprising the photoelectric conversion unit and a plurality of detection units each receiving light emitted by the plurality of light emitters and individually detecting an amount of received light, A first determining step of determining at least one of the predetermined time and a predetermined amount based on a predetermined ratio of a light emission amount to be emitted when each of the plurality of light emitters simultaneously emits light; Each reference value to be detected by the plurality of detecting means when the respective light bodies emit light simultaneously,
A second determining step of determining based on a predetermined ratio of the light emission amount, and a comparing step of comparing each received light amount detected by the plurality of detecting means with each reference value determined by the second determining means. As a result of the comparison in the comparing step, when one of the plurality of received light amounts is different from a reference value corresponding to the one received light amount, an abnormality occurs in the light emitter corresponding to the one received light amount. And a stopping step of stopping the image reading operation of the image reading device upon determining that the light source abnormality is present.

According to the eleventh aspect of the present invention, a light source for irradiating a predetermined image reading surface, a photoelectric conversion unit for receiving light reflected from the image reading surface and converting the reflected light into an electric signal, A plurality of light-emitting members each configured to be supplied with a current and emit light of a different color from each other, and current supply means for supplying a predetermined amount of current to each of the plurality of light-emitting members for a predetermined time, A light source abnormality processing method applied to an image reading apparatus comprising the photoelectric conversion unit, and a plurality of detection units each receiving light emitted by the plurality of light emitters and individually detecting an amount of received light, In a program to be executed by a computer, the light source abnormality processing method may be configured such that the predetermined time period and the predetermined time period are determined based on a predetermined ratio of light emission amounts to be emitted when each of the plurality of light emitters simultaneously emits light. A first determining step of determining at least one of the predetermined amounts; and determining a reference value to be detected by the plurality of detecting means when each of the plurality of light emitters simultaneously emits light, A second determining step of determining based on the ratio, a comparing step of comparing each received light amount detected by the plurality of detecting units with a reference value determined by the second determining unit, and the comparing step As a result of the comparison, when one of the plurality of received light amounts is different from a reference value corresponding to the one received light amount, it is determined that an abnormality has occurred in the illuminant corresponding to the one received light amount. Stopping the image reading operation by the image reading device.

Further, according to the invention described in claim 14,
A light source for irradiating a predetermined image reading surface, photoelectric conversion means for receiving reflected light from the image reading surface and converting the reflected light into an electric signal, and constituting the light source, are supplied with currents and emit light of different colors from each other. A plurality of light-emitting bodies that emit light; a current supply unit that supplies a predetermined amount of current to each of the plurality of light-emitting bodies over a predetermined time; and the photoelectric conversion unit, wherein the plurality of light-emitting bodies emit light. A computer-readable storage medium storing, as a program, a light source abnormality processing method applied to an image reading apparatus including a plurality of detection units each receiving light to be emitted and individually detecting an amount of received light. The abnormality processing method is based on a predetermined ratio of a light emission amount to be emitted when each of the plurality of light emitters simultaneously emits light, based on at least one of the predetermined time and the predetermined amount. A first determination step of determining one of the plurality of light-emitting bodies, and a reference value to be detected by the plurality of detection means when each of the plurality of light-emitting bodies simultaneously emits light, based on a predetermined ratio of the light emission amount. 2, a comparing step of comparing each received light amount detected by the plurality of detecting means with each reference value determined by the second determining means, and a result of the comparison by the comparing step, When one of the plurality of received light amounts is different from the reference value corresponding to the one received light amount, it is determined that an abnormality has occurred in the luminous body corresponding to the one received light amount, and the image read by the image reading device is determined. A stopping step of stopping the reading operation.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a side sectional view showing a configuration of an embodiment of a main part of the image reading apparatus according to the present invention.

As a typical configuration of the image reading apparatus, there are an image reading apparatus using a reduced optical system image sensor and an image reading apparatus using a 1: 1 optical system image sensor. The description will be given by taking an image reading apparatus using a sensor as an example.

The essential parts of the image reading apparatus include a platen glass 2-1 on which a document 2-3 is placed, a pressure plate 2-2 which presses the platen glass 2-1 and can be opened and closed, and a platen 2-2. Glass 2-1
And a scanning optical system for reading the original document 2-3 placed thereon.

The scanning optical system includes a contact image sensor (hereinafter referred to as "CIS") 2-4, a carriage 2-5 for holding the CIS 2-4, and a carriage 2-5 for reading an original.
2-5, a timing belt 2-8 having a ring-shaped part fixed to the carriage 2-5, and a timing belt 2
-8, a pulley 2-6, 2-7 which is suspended, a stepping motor 2-10 for rotating the pulley 2-6, and a home position sensor 2-11 for detecting the position of the carriage 2-5 in the sub-scanning direction. It is composed of

A white reference plate 2-13 which is used as a white reference in light amount adjustment control and shading correction is provided at an end of the document table glass 2-1 on the side of the home position sensor 2-11.

Reference numeral 2-12 denotes an operation unit, the detailed configuration of which is shown in FIG.

The operation section 2-12 includes a switch for operating the image reading apparatus and a display section for displaying the state of the image reading apparatus. The switch includes a start section for starting a reading operation. Key 2-12-1, stop key 2-12- for interrupting the reading operation
2. Keys 2-12-7 for selecting a desired document color. In addition, as the display unit, R (red), G indicating that the light emitting operation is being performed corresponding to the LED lamps 2-12-3 and the three color LED light sources indicating that the reading is being performed.
(Green), B (blue) LED lamps 2-12-4, 5, 6
It consists of.

FIG. 4 is a perspective view showing the configuration of the CIS 2-4.

In the figure, 2-4-1 is a linear light source unit, which is an LED light source unit 2 having LED light sources of three colors.
-4-2 (only one is shown in FIG. 4 but there are two)
And a light guide 2-4 extending from the LED light source unit 2-4-2 in the main scanning direction to uniformly diffuse the light emitted from the LED light source unit 2-4-2 in the main scanning direction.
-3. The light guide 2-4-3 is formed of a transparent material and has a rectangular parallelepiped shape. LED light source units 2-4-2 are arranged at both ends in the longitudinal direction (main scanning direction). A light reflection / diffusion region is formed at one end (the lower end in FIG. 4) in the vertical direction (the vertical direction in FIG. 4). Two LED light source units 2-4
-2 is emitted into the light guide 2-4-3, is reflected and diffused in the light reflection / diffusion region, and is emitted outside from the other end (upper end in FIG. 4) facing the light reflection / diffusion region. The document 2-3 is illuminated linearly.

The irradiation light emitted from the light guide 2-4-3 is reflected by the original 2-3 on the platen glass 2-1.
The reflected light passes through the SELFOC lens array 2-4-4 and the light receiving element 2-4-4 fixed on the substrate 2-4-6.
5. The incident light is a light receiving element 2-4-5.
, And are sequentially output as image signals in the main scanning direction for each pixel. The light receiving element 2-4-5 is formed of a filter of three colors for each pixel and a CCD (charge coupled device) for each color.

As will be described in detail later, the LED light source unit 2-4-2 is individually driven by a constant current circuit for each LED light source of each color, and the lighting time of one line is controlled by PWM (pulse width modulation). You.

The light receiving element 2-4-5 is turned on only for a time corresponding to one line (main scanning) of reading scanning, and causes each element to read all pixels constituting one line. A drive clock pulse, a reset pulse for resetting the accumulated charge for each element after outputting the accumulated charge of each element, a start pulse serving as a trigger for starting reading of one line, and the like are given. Timing of these pulses , An image signal is output from the light receiving element 2-4-5 for each pixel.

FIG. 5 is a block diagram showing the configuration of the control unit of the image reading apparatus.

Reference numeral 4-1 denotes an analog signal processing circuit.
It comprises a GC circuit 4-1-1 and an A / D conversion circuit 4-1-2. The AGC circuit 4-1-1 samples the image signal of the original image sent from the CIS 2-4, corrects the offset level of the signal, and amplifies the signal. The A / D conversion circuit 4-1-2 converts an analog signal into a digital signal.

Reference numeral 4-2 denotes an LE which is a light source of the CIS 2-4.
LE for controlling light emission of each color of D light source unit 2-4-2
D control circuit, which will be described later in detail with reference to FIG.
Control is performed such that the combined color of the light emission of each color is always white.

Reference numeral 4-3 denotes a control circuit.
-3-1, memory 4-3-2, interface circuit 4-
3-5, CPU for controlling the entire image reading apparatus 4-
3-3, memory for storing control program 4-3-
4. Motor driver circuit (DRV) 4-3-6.

The image processing circuit 4-3-1 performs processing on the image data digitized by the analog signal processing circuit 4-1.
Shading correction, spatial filter processing, magnification correction, luminance signal conversion, binarization processing, and the like are performed, and the processed image data is stored in the memory 4-3-2.

The CPU 4-3-3 sets an offset value, a gain value, and the like required by the analog signal processing circuit 4-1; sets a PWM control value required by the LED control circuit 4-2; -Setting of parameters required for image processing in -3-1, interface circuit 4-3-5
It sets various operating conditions of the image reading apparatus, such as setting interface conditions in the MFP, controls the start and stop of the operation of the image reading apparatus, controls the interface with external devices, and the like.

The memory 4-3-2 has an image processing circuit 4-
The image data subjected to the image processing in 3-1 is stored.
The PU 4-3-3 can read this image data via the data bus and the image processing circuit 4-3-1.

Further, the CPU 4-3-3 outputs a signal based on the output signal of the home position sensor 2-11.
IS2-4 is moved to a predetermined initial position, and then the stepping motor 2-1 is passed through a motor driver circuit 4-3-6.
A predetermined excitation pattern is output to 0. This gives C
IS2-4 is moved in the sub-scanning direction at a constant speed, and an image is read.

Next, the reading operation of the image reading apparatus will be described.

Before reading the original 2-3, the carriage 2-5 is positioned at the home position (initial reference position). That is, the CPU 4-3-3 drives the stepping motor 2-10 to drive the carriage 2-5 once in the sub-scanning direction regardless of whether the carriage 2-5 is detected or not detected by the home position sensor 2-11. Then, the carriage 2-5 is separated from the home position. Next, the stepping motor 2-10 is reversed to return the carriage 2-5 in the reverse direction. When the carriage 2-5 is detected by the home position sensor 2-11, the stepping motor 2-10 is thereafter driven by a predetermined pulse. To stop. As a result, the CIS 2-4 has moved to the predetermined initial position.

Next, the CIS2-moved to the predetermined initial position
4 reads the white reference plate 2-13, and reads the CPU 4-3-3.
Sets the PWM value of each color of the LED light source constituting the LED light source unit 2-4-2.

The setting of the PWM value is performed based on the image signal value output from the CIS 2-4. First, the offset value and the gain value of the analog signal processing circuit 4-1 are set to predetermined reference values, and the LED light source unit is set. 2-4-2 LED of each color
After setting the light amount ratio of the light source, the PWM value of each color is set (details will be described with reference to FIGS. 6 to 8).

Next, each color LED light source of the LED light source unit 2-4-2 is turned on at a set light amount ratio, irradiates the white reference plate 2-13, and sets a correction value for shading correction.

When such processing is completed, the stepping motor 2-10 is driven in the sub-scanning direction, and reading of a document image is started.

When the image reading is started, the read image of the document is photoelectrically converted by the CIS 2-4, and the image signal of the obtained document image is processed by the analog signal processing circuit 4-1. First, the signal is sampled by the AGC circuit 4-1-1, the offset level of the signal is corrected, the signal is amplified, and when the analog signal processing is completed, the signal is converted into a digital signal by the A / D conversion circuit 4-1-2. Converted and output.

The image processing circuit 4-3-1 in the control circuit 4-3 performs shading correction, spatial filter processing, magnification correction, luminance signal conversion, and binarization processing on the digitized image data. It is performed and stored in the memory 4-3-2. The conditions and operation parameters of each image processing in the image processing circuit 4-3-1 are controlled by the control circuit 4-3.
Can be set by the CPU 4-3-3.

The image data stored in the memory 4-3-2 is output via the interface circuit 4-3-5 while synchronizing with the external device at the control timing.

FIG. 1 is a block diagram showing the internal configuration of the LED control circuit 4-2 and related parts connected to the LED control circuit 4-2. The control circuit 4-3 includes a CPU
Only 4-3-3 and the memory 4-3-4 are shown.

The LED control circuit 4-2 is provided with LED drive circuits 4-2-1, 4-2-2 and 4-2-3.
Each color LED light source in the ED light source unit 2-4-2 (Red,
Green, Blue). LED
The driving circuits 4-2-1, 4-2-2, and 4-2-3 have the same configuration, and include a constant current circuit and a switching circuit. Each color LE in the LED light source unit 2-4-2
A common power supply is connected to each anode of the D light source to supply the same electric potential, and each cathode is connected to an LED driving circuit 4-2.
A constant current is supplied from 1, 4-2-2 and 4-2-3 for the switch-on time (lighting time) specified by the control signal. Each constant current is output from the corresponding constant current circuit, and each switch-on time (lighting time) is created by the corresponding switching circuit. The control circuit 4-3 determines the magnitude of the constant current and the switch-on time (lighting time) based on the image signal value output from the CIS 2-4.

The operation unit 2-12 controls each initial value and each color LE in the LED control circuit 4-2 via the control circuit 4-3.
The light amount ratio of the D light source can be set.

The light receiving element 2-4-5 is composed of a plurality of elements provided for each pixel, and each of the plurality of elements includes a CCD for each color (R, G, B). , The received light amount of the CCD for each color is represented by pix_R,
ix_G and pix_B. In addition, the amounts of light emitted by the LED light sources of each color (R, G, B) in the LED light source unit 2-4-2 are defined as l_R, l_G, and l_B, respectively.
The constant current amount supplied to each color LED light source is represented by i
_R, i_G, and i_B, and the time during which each of these constant currents is supplied to the LED light source of each color is t_R, t_
Assuming that G and t_B, the following formula is established.

Pix_R∝l_R = i_R × t_R pix_G∝l_G = i_G × t_G pix_B∝l_B = i_B × t_B Constant current amount i_R, i_G, i_B and time (lighting time)
t_R, t_G, and t_B are determined by the CPU 4-3-3 in the control circuit 4-3 as described later with reference to FIGS.
Are created independently of each other and stored in the memory 4-3-4.

FIGS. 6 to 8 show the constant current amounts i_R, i_G, i_B and the lighting time t performed in the control circuit 4-3.
9 is a flowchart illustrating a procedure of a creation process of _R, t_G, and t_B. Hereinafter, description will be given along the steps in the figure.

Step S1: First, each initial value and light amount ratio are set. That is, the LED drive circuits 4-2-1, 4-2-1
The constant current amounts i_R, i_G, and i_B output by the respective constant current circuits in 2-2 and 4-2-3 are respectively initialized to i_0.
[A], and the lighting times t_R, t_G, and t_B created by each switching circuit are set to an initial value t_0 [se
c]. Further, a predetermined current value which is the minimum variable unit when changing the constant current amount is Δi [A], and a predetermined time which is the minimum variable unit when changing the lighting time is Δt.
[Sec], and 1 in the light receiving element 2-4-5.
The accumulation time for the line is set to t_0 [sec].

The light receiving amount pi when the CCD for each color in each of the light receiving elements 2-4-5 receives white light.
The ratio of x_R, pix_G, pix_B is preset in the image reading device (previously stored in the memory in the control circuit 4-3) or can be set by the user of the device. The ratio is pix_
If it is assumed that R: pix_G: pix_B = a: b: c, the control circuit 4-3 uses this ratio to obtain the light receiving element 2
The pixel signal output target values d_R, d_G, and d_B to be output by the CCDs for each color in each element of −4-5 are calculated based on the following equations.

D_R = a / (a + b + c) × 255 d_G = b / (a + b + c) × 255 d_B = c / (a + b + c) × 255 Here, the LED light source unit 2 is used. -Each L in -4-2
Reflected light from the white reference plate 2-13 obtained when all of the ED light sources are turned on, the total of the pixel signal output values received and output by the light receiving element 2-4-5 is defined as 255. When all LED light sources are turned off, the light receiving element 2-
The sum of the pixel signal output values output by 4-5 is set to 0.

Step S2: Red LED light source LED_
A constant current amount i_R (initial i_0 [A]) is supplied to only R over the lighting time t_R (initial t_0 [sec]) to illuminate a single color and illuminate the white reference plate 2-13.

Step S3: The reflected light from the white reference plate 2-13 illuminated in this way is received by the light receiving element 2-4-5. The received light amount pix_R of the red CCD is stored in the memory 4-3-4.

Step S4: Light receiving amount pix_ of the CCD for red in all the elements for one line stored in the memory.
The maximum value pix_max in R is detected, and it is determined whether or not this value is the same as the above-described pixel signal output target value d_R. If they are the same, the process proceeds to step S8; otherwise, the process proceeds to step S5.

Step S5: The maximum value pix_max is compared with the pixel signal output target value d_R, and the maximum value pix_ma is determined.
If x is greater than the pixel signal output target value d_R, the process proceeds to step S6, and if the maximum value pix_max is equal to or less than the pixel signal output target value d_R, the process proceeds to step S7.

Step S6: A value (= t_R-Δt) obtained by reducing the lighting time t_R by the predetermined time Δt is set as a new lighting time t_R, and the process returns to step S2.

Step S7: A value (= i_R + Δi) obtained by increasing the constant current amount i_R by a predetermined current value Δi is set as a new constant current amount i_R, and the process proceeds to step S9.

Step S8: The constant current amount i when the maximum value pix_max is equal to the pixel signal output target value d_R.
_R and the lighting time t_R are stored in the memory 4-3-4.

Step S9: The new constant current amount i_R set in step S7 is changed to a predetermined upper limit value max for red.
_R, the constant current amount i_R is equal to a predetermined upper limit value max_
If it is not less than R, the process proceeds to step S10, and the constant current amount i_
Step S when R is smaller than a predetermined upper limit value max_R
Return to 2.

Step S10: Red LED light source LED
_R is determined to have failed for some reason, and error information indicating the failure of the red LED light source LED_R is stored in the memory 4-3-4.

Thereafter, based on the flowchart shown in FIG. 7, the same processing as in steps S2 to S10 is performed by using a green LED.
The process is performed on the light source LED_G, and based on the flowchart shown in FIG. 8, the same processing as in steps S2 to S10 is performed on the blue LED light source LED_B. In addition,
In the flowcharts shown in FIGS. 6 to 8, the red LED light source LED_R, the green LED light source LED_G, and the blue L
Although the processing is performed in the order of the ED light sources LED_B, the processing is not limited to this order and may be performed in another order.

In step S4, the maximum received light amount pix_ among all the elements for one line stored in the memory is determined.
The reason for detecting max is generally that the light receiving element 2-4-5
There is a variation in the light receiving sensitivity among the elements, and the explanation is omitted here. By performing shading correction, the light receiving sensitivity correction of matching the light receiving sensitivity that varies between the elements to the maximum light receiving sensitivity is another processing. It is performed in. Therefore, here, the maximum received light amount pix_m
ax is detected so as to be the same as the pixel signal output target value d_R, and from this, the maximum received light amount pix_max is detected.

Thus, the LED light sources of the respective colors are simultaneously emitted using the constant current amount and the lighting time for the respective colors determined by executing the processing shown in FIGS. 6 to 8, and the composite white light obtained thereby is obtained. In, the light amount ratio set in advance is maintained, and the image reading operation (image input operation) is performed in a state where the original is irradiated with the white light.

When the three color LED light sources are turned on at the same time, the light quantity is insufficient due to the deterioration of the light quantity with time of the LED and the like, and the pixel signal output value of the light receiving element becomes 255 at the time of simultaneous lighting of three colors. When the state of not reaching occurs, the amount of constant current supplied to all the LED light sources of the three colors is increased without changing the ratio between them to reach the value of 255.

In steps S6 and S7 shown in FIG. 6, since the light amount of the LED light source is determined by the product of the LED lighting time and the constant current amount, both the lighting time and the constant current amount are varied. However, instead of this, one of the lighting time and the constant current amount may be fixed, and only the other value may be changed.

Next, a process when error information indicating a failure of the LED light source in the CIS 2-4 is stored in the memory 4-3-4 will be described.

When a failure occurs in any of the three color LED light sources, the reading of the image is stopped and the failed LED light source is displayed on the operation unit 2-12.

That is, when the LED light sources of each color are normal, R (red), G
(Green), B (blue) LED lamps 2-12-4, 5, 6
Are turned on to indicate that all three color LED light sources emit light normally, and therefore all document colors can be read.

However, for example, if the R (red) LED light source fails, the R (red) LE
The LED lamp 2-12-4 corresponding to the D light source blinks to indicate that a failure has occurred in the R (red) LED light source. When the R (red) LED light source does not emit light, the B (blue) original cannot be read.
LED lamp 2-12 corresponding to the R (red) LED light source
After performing the blinking display of -4 for a predetermined time, the LE of B (blue) is displayed.
The LED lamp 2-12-6 corresponding to the D light source is turned off, thereby indicating that the B (blue) original cannot be read.

When the user who sees such a display operates the start key 2-12-1 for starting the reading operation, desiring to read the original even if he cannot read the blue portion of the original, Reading continues as it is.

In the above, the case where the R (red) LED light source has failed has been described as an example, but the L (green) and B (blue) L
The same applies when the ED light source fails.

By performing the display as described above, LE
It is possible to prevent a problem that the document reading device is operated unnecessarily despite the failure of the D light source. In the case of a monochrome original, the reading operation can be continued.

In the above embodiment, the control circuit 4
-3, the software control is performed using the CPU 4-3-3. However, the same control may be performed by configuring the control circuit with hardware with the gate array as the main.

The program code itself of the software for realizing the functions of the above-described embodiments may constitute the present invention, and a storage medium storing the program code may constitute the present invention. .

As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk,
Hard disk, optical disk, magneto-optical disk, CD-
A ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, and the like can be used.

Further, when the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also an OS or the like running on the computer based on the instruction of the program code. It goes without saying that the present invention includes a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It is needless to say that the present invention includes a case where the CPU or the like provided in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments. .

[0079]

As described in detail above, according to the first, eighth, eleventh or fourteenth aspects of the present invention,
When each of the plurality of light emitters that emit light of different colors emits light at the same time, the light is detected by the plurality of detection units that receive the light emitted by the plurality of light emitters and individually detect the amount of received light. Each reference value to be determined is determined based on a predetermined ratio of the light emission amount of each of the plurality of luminous bodies, each received light amount detected by the plurality of detection means is compared with each of the determined reference values, When one of the plurality of received light amounts is different from a reference value corresponding to the one received light amount, it is determined that an abnormality has occurred in the illuminant corresponding to the one received light amount, and the image is read by the image reading device. Stop reading operation.

In this way, if a light source lighting abnormality occurs when reading an image using the combined light obtained by simultaneously lighting a plurality of light sources of different colors, the image reading operation is stopped and the image reading operation is stopped. Useless operation of the device can be prevented.

According to the second, ninth, twelfth, or fifteenth aspect of the present invention, the image reading device is provided corresponding to each of the plurality of light emitters. The display device further includes a plurality of display means for displaying that the body is operating normally by a first display method and displaying that the body is not operating properly by a second display method. And operating the display means corresponding to the illuminant for which the abnormality determination has been made by the second display method.

As a result, it is possible to inform the user of the illuminant in which the abnormality has occurred, and at the same time, it is easy to identify the faulty part by a repair service or the like.

According to the fourth, tenth, thirteenth, or sixteenth aspect of the present invention, the display means corresponding to the illuminant for which the abnormality has been determined is operated by the second display method. After a lapse of a predetermined time from, the second display method is stopped, and provided in correspondence with the illuminant that emits a color complementary to the color of the light emitted by the illuminant that has been determined to be abnormal. The display means is operated by the third display method.

Thus, it is possible to inform the user of a document color that cannot be read normally. If the user determines that it is not necessary to read a document of that color normally, the user can continue reading the image. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal configuration of an LED control circuit and related parts connected to the LED control circuit.

FIG. 2 is a side sectional view showing a configuration of an embodiment of a main part of the image reading apparatus according to the present invention.

FIG. 3 is an external view illustrating a configuration of an operation unit.

FIG. 4 is a perspective view illustrating a configuration of a contact image sensor (CIS).

FIG. 5 is a block diagram illustrating a configuration of a control unit of the image reading apparatus.

FIG. 6 is a flowchart (１ ／) showing a procedure of a process of creating a constant current amount and a lighting time performed in a control circuit.

FIG. 7 is a flowchart (2/3) showing a procedure of a process of creating a constant current amount and a lighting time performed in the control circuit.

FIG. 8 is a flowchart (3/3) showing a procedure of a process of creating a constant current amount and a lighting time performed in the control circuit.

[Explanation of symbols]

2-4 Contact image sensor (CIS, current supply means) 2-4-1 Linear light source unit 2-4-2 LED light source unit (light source) 2-4-3 Light guide 2-4-5 Light receiving element ( 2-11 Home position sensor 2-12 Operation unit 2-12-4, 5, 6 LED lamp (plural display units) 2-13 White reference plate 4-1 Analog signal processing circuit 4-2 LED control Circuit 4-3 Control circuit 4-3-3 CPU (first determining means, second determining means, comparing means, stopping means, first display control means, second display control means) 4-3-4 memory

Continued on front page F term (reference) 5B047 AA01 AB04 BA02 BB02 BC05 BC11 BC23 CA02 CB04 DC06 5C062 AA01 AB33 AB41 AC55 AE15 AF15 5C072 AA01 BA20 CA05 CA14 CA17 DA02 EA05 QA10 UA13 XA10

Claims (16)

[Claims] 1. An image reading apparatus comprising: a light source for irradiating a predetermined image reading surface; and photoelectric conversion means for receiving reflected light from the image reading surface and converting the reflected light into an electric signal. A plurality of light-emitting bodies to which currents are respectively supplied to emit light of different colors; a current supply unit for supplying a predetermined amount of current to each of the plurality of light-emitting bodies over a predetermined time; A first determination unit that determines at least one of the predetermined time and a predetermined amount based on a predetermined ratio of light emission amounts to be emitted when each of the light emitters emits light at the same time; and the photoelectric conversion unit. A plurality of detecting means for respectively receiving light emitted by the plurality of light emitters and individually detecting an amount of light received; and Second determining means for determining each reference value to be determined based on a predetermined ratio of the light emission amount; and each of the light receiving amounts detected by the plurality of detecting means as respective reference values determined by the second determining means. Comparing means for comparing the received light amount with each of the plurality of received light amounts;
And stopping means for determining that an abnormality has occurred in the illuminant corresponding to the one light reception amount and stopping the image reading operation when the reference value corresponding to the one light reception amount is different from the reference value corresponding to the one light reception amount. An image reading apparatus characterized by the above-mentioned. 2. A method according to claim 1, wherein each of said plurality of light emitters is provided in correspondence with said plurality of light emitters. A plurality of display means for displaying in the second display method; and a first display control means for operating, among the plurality of display means, the display means corresponding to the illuminant whose abnormality has been determined by the second display method. The image reading device according to claim 1, comprising: 3. The method according to claim 2, wherein each of the plurality of display units includes a light-emitting device, the first display method is lighting of the light-emitting device, and the second display method is blinking of the light-emitting device. The image reading device according to claim 2, wherein: 4. A method according to claim 1, wherein said display means corresponding to said illuminant for which said abnormality has been determined is operated by said first display control means in accordance with said second display method. The method is stopped, and the display means provided corresponding to the illuminant that emits a color having a complementary color relationship with the color of the light emitted by the illuminant whose abnormality has been determined is operated by the third display method. 3. The image reading apparatus according to claim 2, further comprising a second display control unit. 5. The display device according to claim 1, wherein each of the plurality of display units includes a light emitting device, the first display method is lighting of the light emitting device, the second display method is blinking of the light emitting device, and the third displaying method is blinking of the light emitting device.
5. The image reading apparatus according to claim 4, wherein the display method is such that the light emitting device is not turned on. 6. The image reading apparatus according to claim 1, wherein each of the plurality of light emitters includes a light emitting diode that emits light of a different color. 7. A light guide, which internally reflects and diffuses light incident from the plurality of light emitters, and emits a band-like light flux to the document. The image reading device according to claim 1. 8. A light source for irradiating a predetermined image reading surface, photoelectric conversion means for receiving reflected light from the image reading surface and converting the reflected light into an electric signal, and comprising the light source. A plurality of light-emitting bodies that emit light of different colors, and current supply means for supplying a predetermined amount of current to each of the plurality of light-emitting bodies for a predetermined time,
A light source abnormality processing method applied to an image reading apparatus comprising the photoelectric conversion unit and a plurality of detection units each receiving light emitted by the plurality of light emitters and individually detecting an amount of received light, A first determining step of determining at least one of the predetermined time and a predetermined amount based on a predetermined ratio of light emission amounts to be emitted when each of the plurality of light emitters simultaneously emits light; A second determining step of determining each reference value to be detected by the plurality of detecting means when each of the luminous bodies emits light at the same time based on a predetermined ratio of the light emission amount; and detecting the reference value by the plurality of detecting means. A comparing step of comparing each received light amount with each reference value determined by the second determining unit; and, as a result of the comparison in the comparing step, one of the plurality of received light amounts A stop step of determining that an abnormality has occurred in the light emitter corresponding to the one received light amount and stopping an image reading operation by the image reading device when the reference value corresponding to the one received light amount is different; A light source abnormality processing method comprising: 9. The image reading apparatus according to the first display method, wherein the first reading method displays that the corresponding light emitter provided normally for each of the plurality of light emitters is operating normally. The display device further includes a plurality of display means for displaying, by a second display method, that the light emitting device is not operating, and a display means corresponding to the illuminant for which the abnormality determination has been made, among the plurality of display means, is displayed on the second display means. 9. The light source abnormality processing method according to claim 8, further comprising a first display control step operated by the method. 10. The display of the second display after a predetermined time has elapsed since the display means corresponding to the illuminant whose abnormality has been determined by the first display control step is operated by the second display method. The method is stopped, and the display means provided corresponding to the illuminant that emits a color having a complementary color relationship with the color of the light emitted by the illuminant whose abnormality has been determined is operated by the third display method. The light source abnormality processing method according to claim 9, further comprising a second display control step. 11. A light source for irradiating a predetermined image reading surface, photoelectric conversion means for receiving reflected light from the image reading surface and converting the light into an electric signal, and constituting the light source. A plurality of light-emitting bodies that emit light of different colors, and current supply means for supplying a predetermined amount of current to each of the plurality of light-emitting bodies for a predetermined time,
A light source abnormality processing method applied to an image reading apparatus comprising the photoelectric conversion unit, and a plurality of detection units each receiving light emitted by the plurality of light emitters and individually detecting an amount of received light, In a program for causing a computer to execute, the light source abnormality processing method includes the steps of: performing the light source abnormality processing method based on a predetermined ratio of a light emission amount to be emitted when each of the plurality of light emitters simultaneously emits light; A first determination step of determining at least one, and determining each reference value to be detected by the plurality of detection means when each of the plurality of light emitters emits light simultaneously based on a predetermined ratio of the light emission amount. And a comparing step of comparing each received light amount detected by the plurality of detecting means with each reference value determined by the second determining means. When one of the plurality of received light amounts is different from a reference value corresponding to the one received light amount as a result of the comparison in the comparing step, an abnormality occurs in the light emitter corresponding to the one received light amount. And a stop step of stopping the image reading operation by the image reading apparatus upon determining that the image reading operation is performed. 12. The image reading device according to a first display method, wherein the first reading method displays that a corresponding light emitting body provided for each of the plurality of light emitting bodies is operating normally. The display device further includes a plurality of display means for displaying that it is not operating by a second display method, wherein the light source abnormality processing method is one of the plurality of display means.
12. The program according to claim 11, further comprising: a first display control step of operating a display unit corresponding to the illuminant for which the abnormality determination has been made by the second display method. 13. The light source abnormality processing method according to claim 1, wherein a predetermined time elapses after a display unit corresponding to the illuminant for which the abnormality is determined in the first display control step is operated by the second display method. Later, while stopping the second display method, the display means provided corresponding to the illuminant that emits a color that is complementary to the color of the light emitted by the illuminant that has been determined to be abnormal, 13. The program according to claim 12, further comprising a second display control step operated by the display method of claim 3. 14. A light source for irradiating a predetermined image reading surface, photoelectric conversion means for receiving reflected light from the image reading surface and converting the light into an electric signal, and comprising the light source. A plurality of light-emitting bodies that emit light of different colors, and current supply means for supplying a predetermined amount of current to each of the plurality of light-emitting bodies for a predetermined time,
A light source abnormality processing method which is applied to an image reading apparatus which comprises the photoelectric conversion unit and includes a plurality of detection units each receiving light emitted by the plurality of light emitters and individually detecting an amount of received light is programmed. In a storage medium readable by a computer, the light source abnormality processing method is based on a predetermined ratio of a light emission amount to be emitted when each of the plurality of light emitters emits light at the same time. A first determining step of determining at least one of the predetermined amounts; and determining each of the reference values to be detected by the plurality of detecting means when each of the plurality of light emitters emits light at the same time. A second determining step of determining based on the ratio, and determining each received light amount detected by the plurality of detecting units with a reference value determined by the second determining unit. A comparing step of comparing each of the plurality of received light amounts and a reference value corresponding to the one received light amount as a result of the comparison in the comparing step; A stopping step of determining that an abnormality has occurred and stopping the image reading operation by the image reading device. 15. The image reading apparatus according to a first display method, wherein the first reading method displays that a corresponding light emitting body provided for each of the plurality of light emitting bodies is operating normally. The display device further includes a plurality of display means for displaying that the light source is not operating by the second display method, wherein the light source abnormality processing method is one of the plurality of display means.
15. The storage medium according to claim 14, further comprising: a first display control step of operating a display unit corresponding to the illuminant for which the abnormality has been determined by the second display method. 16. The light source abnormality processing method according to claim 1, wherein a predetermined time has passed since the display means corresponding to the illuminant for which the abnormality was determined in the first display control step was operated by the second display method. Later, while stopping the second display method, the display means provided corresponding to the illuminant that emits a color that is complementary to the color of the light emitted by the illuminant that has been determined to be abnormal, 16. The storage medium according to claim 15, further comprising a second display control step operated by the display method of claim 3.