JP2004064406A - Image reading device and its control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct control for reducing downtime if a failure occurs at a LED (light emitting diode), in an image reading device with a LED array system having a plurality of LEDs in one dimensional arrangement. <P>SOLUTION: The device comprises a LED array light source having a plurality of LEDs in one dimension arrangement, a linear image sensor for receiving reflected light of a manuscript or a reference white board to read images, an abnormality detecting means for detecting abnormality in the LEDs, a display operating means for displaying the status of the device and receiving an operation for the device, and a control means for controlling to conduct a manuscript reading operation and read the manuscript if the position of an abnormal LED is out of the range of the manuscript, or controlling to display "LED is abnormal" on the display operating means and receive selection of start or stop of manuscript reading from an operator if the position of the abnormal LED is in the range of the manuscript, when the abnormal LED is detected by the abnormality detecting means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus having an array type light source illumination system in which a plurality of light emitting elements are arranged.
[0002]
[Prior art]
Conventionally, a light source such as a halogen lamp, a fluorescent lamp, or a xenon tube has been used as a light source of an image reading apparatus. However, each of the above light sources has various problems such as large heat generation of the light source, large power consumption, large and heavy lamp outer shape, necessity of high-voltage power supply, and long time until light quantity stabilization. In recent years, the sensitivity of a line image sensor that reads a line image of a document has been improved, and an image signal can be extracted with a small amount of light. In order to cope with this situation, the LED emits a small amount of light but generates a small amount of heat and consumes a small amount of power. Therefore, an LED array light source having a plurality of LEDs arranged as an illumination system has been proposed. As described above, the LED is considered as a light source that can solve the above problems.
[0003]
There are the following light sources using LEDs. FIG. 12 shows the configuration. Chip-type LEDs 1201 are mounted in a row on a substrate 1202 provided with circuit conductors, light guides 1203 are provided in the direction of light emission of the LEDs, and light from the LEDs is made uniform in the longitudinal direction to illuminate a document.
[0004]
Further, there is the following as another configuration. FIG. 13 shows the configuration. Cap-type LEDs 1301 are mounted in a row on a substrate 1302 provided with circuit conductors, and light from the LEDs is made uniform in the longitudinal direction to illuminate a document.
[0005]
On the other hand, an image reading device is an image scanner using a reduction optical system formed by a combination of a CCD and a lens. In addition, an LED or a xenon lamp or the like is used as a light source. Alternatively, a so-called contact image sensor (hereinafter, referred to as CIS) using a CMOS line sensor has been increasingly used. The CIS is a close-contact type imaging system in which a sensor, a lens array, and a light source are integrated, and does not require an optical path. Therefore, the image reading apparatus using the CIS has a simple configuration that does not require a mirror or a complicated driving system, and only needs to be configured with a driving system that scans the CIS itself in the reading direction. It is also possible to configure the reading device with simple steps. FIG. 2 shows a structural development of the CIS. FIG. 2 is a view of the CIS as viewed from above, a view as viewed from the side, and a cross-sectional view. The light source is a configuration using a cap-type LED array light source. The CIS module 102 includes a cover glass 201, an LED array light source 202 configured by arranging a plurality of cap-type LEDs 208 in a row on a substrate 209, a 1 × imaging lens 203 including a SELFOC lens, a line sensor 204, and the line. The substrate 205 on which the sensor 204 is mounted and the components 205 are attached to the mold 206 to form the integrated CIS module 102.
[0006]
The CIS module 102 forms a line image of a document illuminated by the LED array light source 202 on an image sensor 204 via a SELFOC lens array 203. The analog image signal read by the image sensor 204 is subjected to image processing similarly to a conventional image reading apparatus having a reduction optical system, and is reproduced by a printer, a host computer, or the like.
[0007]
While the size of the aperture of the reduction optical system CCD is 4.7 μm to 7 μm square, the aperture of each pixel of the image sensor 204 in the CIS module 102 is a size and an equal magnification optical system, so that a reading device of 600 dpi is used. Even in the case of, it is 42 um square. For this reason, light sensitivity can be designed to be higher than that of a CCD, and light can be read with a small amount of light without the need for an illumination system used in a reduction optical system. Therefore, many proposals have been made to use an LED as a light source.
[0008]
In the image scanner using the LED array light source as described above, when a part of the LED of the LED array light source is deteriorated or malfunctions, there is a problem that a defective image such as a black stripe or a white stripe is output.
[0009]
Therefore, a method for detecting deterioration or failure of the LED has been proposed. For example, when a light quantity shortage due to deterioration or failure of the LED is detected, the adjusting means adjusts the light emission quantity of the LED, performs control to compensate for the light quantity shortage by another LED, or stops the reading operation as an error. Has been proposed.
[0010]
[Problems to be solved by the invention]
However, in the above-described image reading apparatus, the reading operation is interrupted or stopped when the light emission amount of the LED exceeds the adjustment range or when a failure is detected. Downtime increases, which is very inconvenient for the user.
[0011]
Also, depending on the size of the document and the positional relationship between the failed LED and the reading operation may be possible without the influence of the failure, the reading operation is interrupted or stopped, which is inefficient.
[0012]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems, and an image reading apparatus according to claim 1 is configured such that an array-type light source in which a plurality of light-emitting elements are arranged, and light is irradiated by the array-type light source. An image sensor for reading an image recorded on a document, abnormality detection means for detecting an abnormality in the light emitting element, and whether the abnormal light emitting element in which the abnormality is detected by the abnormality detection means irradiates the document reading range Determining means for determining whether or not the abnormal light emitting element irradiates the document reading range by the determining means; and reading operation of an image recorded on the document by the image sensor when determining that the abnormal light emitting element irradiates the document reading range. Is controlled to perform a predetermined process before performing the process, and when the determination unit determines that the abnormal light emitting element is to irradiate the outside of the document reading range, And having a control means for controlling so as to perform the reading operation of the image recorded on the document to the image sensor without performing the process.
[0013]
The control program according to claim 10 includes an array-type light source in which a plurality of light-emitting elements are arranged, and a linear image sensor that reads an image recorded on a document illuminated by the array-type light source. A control program for controlling the image reading device, an abnormality detection step of detecting an abnormality of the light emitting element, a warning step of warning when the abnormality of the light emitting element is detected in the abnormality detection step, A determining step of determining whether or not the abnormal light emitting element whose abnormality has been detected in the abnormality detecting step is to irradiate the inside of the document reading range; and in the determining step, the abnormal light emitting element irradiates the inside of the document reading range Before the image sensor performs an operation of reading an image recorded on the original, Control to perform a predetermined process, and when it is determined in the determination step that the abnormal light emitting element is to irradiate the outside of the document reading range, the image sensor does not perform the predetermined process. And a control step of performing a reading operation of an image recorded on the document.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described.
[0015]
(Example 1)
Hereinafter, a first embodiment according to the present invention will be described in detail with reference to the accompanying drawings.
[0016]
FIG. 1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.
[0017]
In FIG. 1, reference numeral 101 denotes an image scanner unit, which reads an image recorded on a document and performs digital signal processing. Reference numeral 102 denotes a CIS module built in the image scanner unit 101; 105, a platen glass (platen); 106, a reading glass; 107, a reference white plate; and 103, an automatic document feeder (hereinafter, referred to as ADF).
[0018]
Next, the operation of the entire apparatus will be described. First, an original platen scanning operation for reading an original on the original platen glass 105 will be described.
[0019]
In the image scanner unit 101 shown in FIG. 1, first, the CIS module 102 is moved under the reference white plate 107 and read, and shading correction is performed by the read image signal. Then, while irradiating the original placed on the original table glass 105 with the light of the LED array light source 202 built in the CIS module 102, the original is scanned with respect to the electrical scanning direction (main scanning direction) of the reading sensor array. The entire surface of the document is scanned by mechanically moving at a speed V in a vertical direction (sub-scanning direction). Light reflected from the document is imaged on a line sensor 204 by a lens 203.
[0020]
The line sensor 204 decomposes light information from the document into, for example, red (R), green (G), and blue (B) color components, reads the color components in full color, and outputs RGB color signals to an image signal processing unit. The reading sensor array of each color component of the line sensor 204 is composed of 7500 pixels, and is 297 mm in the short side direction of the A3 size document which is the largest size among the documents placed on the platen glass 105. It can be read at a resolution of 600 dpi.
[0021]
Next, an image signal processing unit that processes an image signal output from the CIS module 102 will be described with reference to FIG. FIG. 3 is a block diagram of the image signal processing unit.
[0022]
An analog signal output from the line sensor 204 in the CIS module 102 is amplified in the AMP 303 and converted into a digital signal in the A / D converter 304. Then, the signals are rearranged into one-line signals in the rearrangement circuit 305, and shading correction is performed in the shading correction circuit 306. Thereafter, the image is output by a printer via the I / F circuit 307 or reproduced by a host computer or the like. Reference numeral 308 denotes a CPU for calculating shading data and the like and controlling the image scanner unit 101, and reference numeral 309 denotes a power supply circuit for turning on the LED array light source 202. An operation unit 310 of the image reading apparatus displays a status of the image reading apparatus or receives a reading command from a user.
[0023]
Next, a drift scanning operation for reading an image recorded on the document on the drift glass 106 while transporting the document 104 by the ADF 103 will be described.
[0024]
First, the CIS module 102 is moved below the reference white plate 107, and the read image signal processing unit performs shading correction. Next, the CIS module 102 is moved to the flow reading position as shown in FIG. 1, a predetermined position of the flow reading glass 106 is irradiated with light from the LED array light source 202, and an image recorded on the document 104 conveyed by the ADF 103. Read. The image signal read by the CIS module 102 is the same as in the case of the original platen scanning operation.
[0025]
5 to 7 are cross-sectional views of the image scanner in the main scanning direction. Reference numeral 210 denotes a certain LED in the LED array light source 202, which indicates an LED in an abnormal state such as deterioration or failure. For example, the position of the LED 210 has no effect on irradiating an A4R document in the main scanning direction, and has a position on the A210 that irradiates an A4 document.
[0026]
FIG. 5 is an explanatory diagram at the time of shading correction. At the time of shading correction at the time of image reading, LED abnormality detection and abnormal position detection are performed. At the time of shading correction, the image of the reference white plate 107 is sampled. If the LED 210 is abnormal, the distribution of the sample data is as shown in the figure. Since the amount of light is insufficient due to the abnormality of the LED 210, the luminance data of that portion drops. Then, the sample data is compared with a predetermined threshold value A, and when the sample data is smaller than the threshold value, it is determined that the LED is abnormal (deterioration or failure). Here, the predetermined threshold value A is a value that guarantees a sufficient luminance that the output image is not output as a black stripe or a white stripe. Then, it is considered that the LED is abnormal with respect to the drop portion of the luminance data, the position is detected, and stored in a memory (not shown) in the image signal processing unit.
[0027]
FIG. 6 is an explanatory diagram when an original having a width of A4 in the main scanning direction is read. According to the LED abnormality detection and the abnormal position detection at the time of the shading correction, it is determined whether or not the abnormal LED affects the image reading. If the position of the abnormal LED 210 is within the range of the document width and affects the read image, the operation is performed. Alarm display on the display.
[0028]
In FIG. 6, a document 104 is an A4 document, and there is a possibility that a defective image such as a black streak or a white streak may occur in a read image portion when reading an image. Therefore, when the position of the abnormal LED 210 is within the reading range of the A4 width, an alarm is displayed on the operation unit as shown in FIG. 8B, the image reading operation is interrupted, and the user is notified of the image reading operation. Lets you choose whether to continue. If the user acknowledges the occurrence of the defective image and selects to continue the image reading operation, the image reading operation is performed as usual if the image reading operation is continued. On the other hand, if the user selects to stop the reading operation and the image reading cannot be continued, the process ends without performing the image reading operation. When an LED abnormality is detected, an alarm display on the operation unit is performed until the LED array light source is replaced as shown in FIG. 8A even after the image reading is completed. Next, FIG. 7 is an explanatory diagram when reading a document having a width of A4R in the main scanning direction.
[0029]
In FIG. 7, when the original 104 is an A4R original, and the position of the abnormal LED 210 is outside the range of the original width and does not affect the read image,
Although an alarm is displayed on the operation unit as shown in FIG. 8A, since the user is not required to select whether or not to continue the reading operation, the image reading can be performed as usual without interrupting the reading operation. Do. The alarm display on the operation unit in FIG. 8A is performed until the LED array light source is replaced.
[0030]
Hereinafter, the flowchart of FIG. 4 is a program showing a control sequence of the LED abnormality detection and the reading operation, and is stored in a memory (not shown). The program is executed by the CPU 308.
[0031]
When the start button is pressed by the user, in the CIS module located under the white plate in advance, black sampling is performed with the lamp turned off, and black offset correction data is calculated and set (step (hereinafter referred to as S) ) 401). Next, the lamp is turned on under the white plate (S402), and the image of the reference white plate is sampled (S403). Next, shading data is calculated from the sample data of the reference white plate by the CPU 308 and set in the shading memory (S404). Then, the sample data of the white plate is compared with a predetermined threshold A (S405). If all the sample data are larger than the threshold value A (N), it is determined that there is no abnormality in the LED (S406), and the flow shifts to S412 to perform a normal original reading operation and end. If any of the sample data is smaller than the threshold A (Y), it is determined that the LED is abnormal (S406), and the position and width of the place where the sample data is smaller than the threshold A (for example, a range of 25 cm to 26 cm). ) Is detected and stored (S407). Thus, the abnormal LED is detected by calculating the shading data from the sample data of the reference white plate by the CPU 308.
[0032]
Next, the CPU 308 compares the document size detected in advance or the document size designated in advance by the user with the position of the abnormal LED (S408), and if the document size is smaller than the position of the abnormal LED (N), It is determined that there is no influence of the LED (S409), a display is made on the operation unit as shown in FIG. 8A (S413), and the process proceeds to S412 to perform a normal document reading operation and end. If the document size is equal to or larger than the position of the abnormal LED (Y), it is determined that the abnormal LED has an effect (S409), and the LED is abnormal on the display unit and black or white stripes due to the abnormal LED are displayed as shown in FIG. Is displayed (S410). At this time, a display for notifying the width of the black streak or the white streak together with the position within a range of, for example, about 25 cm to 26 cm may be displayed. Thereafter, it is detected whether or not the user has selected to continue or stop reading the document (S411). If the “Yes” button is pressed (S414), and if the continuation is selected (Y), the document reading operation is performed. (S412) and the process ends. If the “No” button is pressed (S 414) and cancel is selected (N), the process ends without reading the document.
[0033]
(Example 2)
Hereinafter, a second embodiment according to the present invention will be described in detail with reference to the accompanying drawings.
[0034]
A description overlapping with the first embodiment will be omitted. In the first embodiment, the image of the white plate is sampled, and the abnormality of the LED is determined based on the sample image. In the present embodiment, the voltage of each LED is monitored by monitoring the voltage of each LED as a means for detecting the abnormal LED. Take a configuration to judge abnormalities. Each voltage signal from each LED is selected by a selector, and is input to a CPU 308 serving as a control unit to determine abnormality of each LED.
[0035]
FIG. 9 is a block diagram of the image signal processing unit. The difference from FIG. 3 is that a selector 311 is added. A voltage signal from each LED of the LED array light source 202 is input to the selector 311, and the selected voltage signal is A / D converted and input to the CPU 308. A control signal for selecting a voltage signal is connected from the CPU 308 to the selector 311.
[0036]
FIG. 10 is a configuration diagram of the LED array light source 202 in the present embodiment. Each voltage signal VN is connected to the selector 311 to detect the voltage VN between the LED and the resistor.
[0037]
The CPU 308 selects and inputs the LED voltage signal A / D-converted by the selector 311 and determines whether or not the voltage is abnormal, thereby detecting the LED failure.
[0038]
A description will be given of LED abnormality detection and document reading control with reference to FIGS. 6 and 7. When reading a document having a width of A4 in the main scanning direction as shown in FIG. 6, after turning on the LED array light source 202, the CPU 308 monitors the voltage signal of each LED to detect an abnormality and an abnormal position of the LED. Based on the result, the CPU 308 determines whether or not the abnormal LED affects the image reading. If the abnormal LED does affect the image reading, an alarm is displayed on the operation unit. In FIG. 6, the original 104 is an A4 original, and when reading an image, there is a possibility that a black line or a white line is generated at that portion of the read image due to the abnormal LED 210. Therefore, when the position of the abnormal LED 210 is within the range of the document width to be read, an alarm is displayed on the operation unit as shown in FIG. 8B, the image reading operation is interrupted, and the user continues to read the image. Is selected. If the user acknowledges the occurrence of the defective image, selects the continuation of the reading operation, and selects the continuation of the image reading, the image reading is performed as usual in the case. On the other hand, if the user selects to stop the reading operation and the image reading cannot be continued, the process ends without performing the image reading operation. When an LED abnormality is detected, an alarm display on the operation unit is performed until the LED array light source is replaced as shown in FIG. 8A even after the image reading is completed.
[0039]
When the position of the abnormal LED 210 is outside the range of the document width and does not affect the read image in the document having the width of A4R in the main scanning direction as shown in FIG. 7, an alarm is displayed on the operation unit as shown in FIG. However, the image reading is performed as usual without interrupting the image reading operation. The alarm display on the operation unit in FIG. 8A is performed until the LED array light source is replaced.
[0040]
Hereinafter, FIG. 11 and subsequent flowcharts of FIG. 11 are programs showing a control sequence of LED abnormality detection and reading operation, and are stored in a memory (not shown). The program is executed by the CPU 308.
[0041]
When the user presses the start button, the CIS module located below the reference white plate performs black sampling with the lamp turned off, and calculates and sets black offset correction data (S1101). Next, the lamp is turned on under the reference white plate (S1102), and the image of the reference white plate is sampled (S1103). Then, shading data is calculated from the sample data of the reference white plate by the CPU 308 and set in the shading memory (S1104). Next, voltage signals of all LEDs are detected while switching the selector 311 (S1105). If there is no abnormality in the voltage signals for all the LEDs (N), it is determined that there is no abnormality in the LEDs (S1106), and the flow shifts to S1112 to perform a normal image reading operation and terminate. If there is an abnormality in the voltage signal (Y), it is determined that the LED is abnormal (S1106), and the position of the abnormal LED is detected and stored (S1107). Next, the CPU 308 compares whether or not the position of the abnormal LED is included in the reading range of the original in the original size detected in advance or the original size designated by the user (S1108). If the position is outside the reading range of the document (N), it is determined that there is no influence of the abnormal LED (S1109), a display is made on the operation unit as shown in FIG. Is performed, and the process ends. If the position of the abnormal LED is within the reading range of the document (Y), it is determined that there is an influence of the abnormal LED (S1109), and an alarm is displayed on the display unit as shown in FIG. 8B (S1110). Thereafter, it is detected whether the user has selected to continue or stop reading the document (S1111), and “Yes” is pressed (S1114). If the continuation is selected (Y), the document reading operation is performed (Y). S1112) The process ends. If "No" is pressed (S1114) and the cancellation is selected (N), the process ends without reading the document.
[0042]
According to the first and second embodiments, the position of the abnormal LED is detected in the image reading apparatus, compared with the width of the read original, and when the position of the abnormal LED is within the range of the read original, the user is notified of the abnormal position. An alarm display notifying the position of the LED is made, and a start or stop of the reading operation is selected. When the position of the abnormal LED is outside the range of the width of the read original and does not affect the output image, the alarm display is performed. By performing a normal reading operation, the output of a defective image such as a black streak or a white streak can be prevented as much as possible, the reading range can be efficiently used, and the downtime of the apparatus can be reduced.
[0043]
In the two embodiments, the detection of the abnormal LED has been described for each image reading sequence. However, the abnormality may be detected only when the power is turned on, or the abnormality may be detected periodically. May be detected.
[0044]
Although the selector 311 has been described as being configured in the LED array light source 202, it may be arranged on a control board in the same manner as the CPU 308.
[0045]
Also, as the LED abnormality detection means, the description has been given in which the CPU determines the LED abnormality by selecting each voltage signal from each LED by the selector, but the current detection means for detecting the current value flowing through each LED is provided. The LED abnormality may be determined based on the detection results.
[0046]
Also, as a result of detecting the abnormal LED, it is determined whether or not the number of abnormal LEDs affects the read image. If the number of abnormal LEDs is equal to or more than a predetermined number, a warning is displayed and an image sensor is displayed. May be stopped.
[0047]
【The invention's effect】
As described above, according to the present invention, in an image reading apparatus using an array type light source in which a plurality of light emitting elements are arranged as a light source for illuminating a document, a defective image such as a black stripe or a white stripe is prevented, and This has the effect of efficiently utilizing the reading range and reducing downtime of the apparatus.
[Brief description of the drawings]
FIG. 1 is a sectional view of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a development view showing an embodiment of the present invention and a structure of a conventional CIS.
FIG. 3 is a block diagram of an image signal processing unit according to the first embodiment of the present invention.
FIG. 4 is a control flowchart according to the first embodiment of the present invention.
FIG. 5 is a diagram showing an arrangement of LED light sources and an image level of a white plate according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating an arrangement of LED light sources and a position of a document according to the first and second embodiments of the present invention.
FIG. 7 is a diagram illustrating an arrangement of LED light sources and a position of a document according to the first and second embodiments of the present invention.
FIG. 8 is a diagram showing an operation unit display according to the first and second embodiments of the present invention.
FIG. 9 is a block diagram of an image signal processing unit according to a second embodiment of the present invention.
FIG. 10 is a diagram illustrating a configuration of an LED light source according to a second embodiment of the present invention.
FIG. 11 is a control flowchart according to a second embodiment of the present invention.
FIG. 12 is a configuration diagram of a conventional LED light source.
FIG. 13 is a configuration diagram of a conventional LED light source.
[Explanation of symbols]
101 Image Scanner 102 CIS Module 103 Automatic Document Feeder (ADF)
201 Cover glass 202 LED light source 203 1 × imaging lens 204 Line sensor 205 Substrate 206 Mold 306 Shading circuit 308 CPU
310 operation unit 311 selector

Claims (18)

An array-type light source in which a plurality of light-emitting elements are arranged,
An image sensor that reads an image recorded on a document irradiated with light by the array-type light source,
Abnormality detection means for detecting an abnormality of the light emitting element,
Determining means for determining whether or not the abnormal light emitting element whose abnormality has been detected by the abnormality detecting means irradiates the area within the document reading range;
When the determination unit determines that the abnormal light emitting element is to irradiate the document reading range, a predetermined process is performed before the image sensor performs an operation of reading an image recorded on the document. If the abnormal light emitting element is determined to irradiate the outside of the document reading range by the determining unit, the image sensor records the document on the image sensor without performing the predetermined process. Control means for controlling to perform a reading operation of the image,
An image reading apparatus comprising: The image reading apparatus according to claim 1, further comprising a warning unit that warns when the abnormality of the light emitting element is detected by the abnormality detection unit. 3. The image reading apparatus according to claim 2, wherein the warning unit issues a warning when the number of the light emitting elements for which the abnormality is detected by the abnormality detecting unit is equal to or more than a predetermined number. The control means is determined by the determination means that the abnormal light emitting element irradiates the document reading range, and when the number of the abnormal light emitting elements is equal to or more than a predetermined number, the abnormal light emitting element is recorded on the document by the image sensor. 4. The image reading apparatus according to claim 1, wherein control is performed such that the predetermined processing is performed before the image reading operation is performed. 2. The image reading apparatus according to claim 1, further comprising a display unit that displays a position of the abnormal light emitting element when the determining unit determines that the abnormal light emitting element irradiates the document reading range. . The apparatus according to claim 1, further comprising an operation unit for receiving an operation from an operator, wherein the predetermined process is a process of receiving a selection operation of starting or stopping document reading by the operation unit. 5. The image reading device according to any one of 5. The apparatus according to claim 1, wherein the abnormality detecting unit detects an abnormality of the light emitting element and a position of the abnormal light emitting element based on image data obtained by reading a reference white plate with the image sensor. Image reading device. Further, the apparatus further includes voltage detecting means for detecting a voltage signal of each of the plurality of light emitting elements, wherein the abnormality detecting means detects an abnormality of the light emitting element and a position of the abnormal light emitting element based on the voltage signal. The image reading apparatus according to claim 1, wherein: Further, there is provided current detection means for detecting a current value flowing through each of the plurality of light emitting elements, and the abnormality detection means detects an abnormality of the light emitting element and a position of the abnormal light emitting element based on the current value. The image reading device according to claim 1, wherein: An array-type light source in which a plurality of light-emitting elements are arranged,
A linear image sensor that reads an image recorded on a document irradiated with light by the array-type light source, and a control program for controlling an image reading apparatus having:
An abnormality detection step of detecting an abnormality of the light emitting element,
A determining step of determining whether or not the abnormal light emitting element in which the abnormality has been detected in the abnormality detecting step is to irradiate the document reading range;
When it is determined in the determining step that the abnormal light emitting element irradiates the area within the document reading range, a predetermined process is performed before the image sensor performs an operation of reading an image recorded on the document. If the abnormal light emitting element is determined to irradiate the outside of the document reading range in the determining step, the image sensor records the document on the image sensor without performing the predetermined process. A control step of performing control so as to perform a reading operation of a read image. The control program according to claim 10, further comprising a warning step of warning when an abnormality of the light emitting element is detected in the abnormality detection step. 11. The control program according to claim 10, wherein in the warning step, a warning is issued when the number of the light emitting elements for which the abnormality is detected in the abnormality detecting step is equal to or more than a predetermined number. In the control step, it is determined that the abnormal light emitting element irradiates the document reading range in the determining step, and when the number of the abnormal light emitting elements is equal to or more than a predetermined number, the abnormal light emitting element is recorded on the document by the image sensor. 13. The control program according to claim 10, wherein the control is performed such that the predetermined process is performed before the image reading operation is performed. 11. The control program according to claim 10, further comprising a display step of displaying a position of the abnormal light emitting element when it is determined in the determining step that the abnormal light emitting element irradiates the inside of the document reading range. Further, the image reading apparatus has an operation unit for receiving an operation from an operator, and the predetermined process is a process of receiving a selection operation of starting or stopping document reading by the operation unit. 15. The control program according to claim 10, wherein: 16. The abnormality detection step according to claim 10, wherein an abnormality of the light emitting element and a position of the abnormal light emitting element are detected based on image data obtained by reading a reference white plate with the image sensor. Control program. Furthermore, the method further includes a voltage detection step of detecting a voltage signal of each of the plurality of light emitting elements, and in the abnormality detection step, detecting an abnormality of the light emitting element and a position of the abnormal light emitting element based on the voltage signal. The control program according to any one of claims 10 to 15, wherein: Further, the method further includes a current detection step of detecting a current value flowing through each of the plurality of light emitting elements, wherein the abnormality detecting means detects an abnormality of the light emitting element and a position of the abnormal light emitting element based on the current value. The control program according to any one of claims 10 to 15, wherein:

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