JP2023080427A - Image reading device, image formation device, and adjustment method for amplification factor - Google Patents

Abstract

To provide an image reading device, an image formation device, and an adjustment method for an amplification factor that can reduce the time required to adjust the amplification factor and also suppress a reduction in the image quality of image data to be read.SOLUTION: An image formation device 100 includes a light source that emits light emitted toward a reading target, a CCD that outputs an electrical signal based on the light reflected by the reading target, an amplification circuit that amplifies the electrical signal output from the CCD, an acquisition processing unit 51 that acquires a physical quantity affecting the electrical signal input to the amplification circuit, and a first adjustment processing unit 52 that adjusts an amplifier factor of the amplification circuit on the basis of the physical quantity acquired by the acquisition processing unit 51.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image reading apparatus, an image forming apparatus, and an amplification factor adjustment method executed by the image reading apparatus.

2. Description of the Related Art In an image reading device such as a scanner, an analog signal output from a photoelectric converter such as a CCD (Charge Coupled Device) is amplified by a signal amplifier such as an amplifier circuit. Then, the amplified analog signal is converted to a digital signal, and the digital signal is output as image data. In this type of image reading device, when the device is started, AGC (Automatic Gain Control) processing for adjusting the amplification factor of the signal amplification section based on image data read from a reference portion such as a white reference plate is executed. .

Further, in order to shorten the time required to adjust the amplification factor of the signal amplification unit, until the elapsed time from the execution of the immediately preceding AGC processing passes a predetermined time, the execution result of the immediately preceding AGC processing is displayed. is known to adjust the amplification factor of the signal amplifier (see Patent Document 1).

JP 2006-238287 A

However, in the configuration in which the amplification factor of the signal amplifier is adjusted using the execution result of the immediately preceding AGC process, the current state of the device cannot be reflected in the amplification factor. Therefore, the image quality of the image data read by the image reading device may deteriorate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus, an image forming apparatus, and an amplification factor adjustment method capable of reducing the time required to adjust the amplification factor and suppressing deterioration in image quality of image data to be read.

An image reading device according to one aspect of the present invention includes a light source, a photoelectric conversion section, a signal amplification section, a sensor, and a first adjustment processing section. The light source emits light that is directed toward the object to be read. The photoelectric conversion unit outputs an electrical signal based on the light reflected by the object to be read. The signal amplification section amplifies the electrical signal output from the photoelectric conversion section. The sensor detects a physical quantity that affects the electrical signal input to the signal amplifier. The first adjustment processing section adjusts an amplification factor of the signal amplification section based on the physical quantity detected by the sensor.

An image forming apparatus according to another aspect of the present invention includes the image reading device and an image forming section. The image forming section forms an image based on image data read by the image reading device.

An amplification factor adjusting method according to another aspect of the present invention includes a light source emitting light emitted toward an object to be read, a photoelectric conversion unit outputting an electrical signal based on the light reflected by the object to be read, and an obtaining step performed by an image reading device comprising a signal amplification unit that amplifies the electrical signal output from the conversion unit; and a sensor that detects a physical quantity that affects the electrical signal that is input to the signal amplification unit; , and an adjustment step. In the obtaining step, the physical quantity is obtained using the sensor. In the adjusting step, an amplification factor of the signal amplifying section is adjusted based on the physical quantity acquired in the acquiring step.

According to the present invention, it is possible to shorten the time required for adjusting the amplification factor and to suppress deterioration in image quality of read image data.

FIG. 1 is a diagram showing the configuration of an image forming apparatus according to an embodiment of the invention. FIG. 2 is a block diagram showing the system configuration of the image forming apparatus according to the embodiment of the invention. FIG. 3 is a diagram showing the configuration of the ADF and image reading section of the image forming apparatus according to the embodiment of the present invention. FIG. 4 is a diagram showing the configuration of the image reading section of the image forming apparatus according to the embodiment of the present invention. FIG. 5 is a flowchart showing an example of amplification factor adjustment processing executed by the image forming apparatus according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiment is an example that embodies the present invention, and does not limit the technical scope of the present invention.

[Configuration of Image Forming Apparatus 100]
First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. Here, FIG. 1 is a sectional view showing the configuration of the image forming apparatus 100. As shown in FIG.

The image forming apparatus 100 is an image processing apparatus having a scanning function of reading an image of a document and a printing function of forming an image based on image data. Specifically, the image forming apparatus 100 is a multifunction machine having multiple functions including the scan function and the print function. Note that the image forming apparatus 100 may be a facsimile machine, a copier, or the like.

As shown in FIGS. 1 and 2, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading section 2, an image forming section 3, a paper feeding section 4, an operation display section 5, a storage section 6, and A control unit 7 is provided. Among these components, the image reading section 2 and the control section 7 constitute the image reading apparatus of the present invention.

ADF 1 conveys a document whose image is to be read by image reading section 2 .

The image reading section 2 realizes the scanning function.

The image forming section 3 realizes the printing function. Specifically, the image forming section 3 includes a photosensitive drum, a charging roller, an optical scanning device, a developing device, a transfer roller, a cleaning device, a fixing device, and a paper output tray. The image forming section 3 forms an image based on the image data read by the image reading section 2 by electrophotography using the above sections.

The paper feeding unit 4 supplies sheets to the image forming unit 3 . Specifically, the paper feed unit 4 includes a paper feed cassette, a sheet transport path, and a plurality of transport rollers.

The operation display unit 5 is a user interface of the image forming apparatus 100 . The operation display section 5 includes a display section and an operation section. The display section displays various types of information according to control instructions from the control section 7 . For example, the display unit is a liquid crystal display. The operation unit inputs various types of information to the control unit 7 according to user's operations. For example, the operation unit is a touch panel.

The storage unit 6 is a nonvolatile storage device. For example, the storage unit 6 is a non-volatile memory such as flash memory.

The control unit 7 controls the image forming apparatus 100 as a whole.

[Configuration of ADF 1 and Image Reading Unit 2]
Next, configurations of the ADF 1 and the image reading section 2 will be described with reference to FIGS. 1 to 4. FIG. Here, FIG. 3 is a sectional view showing a part of the configuration of the ADF 1 and the image reading section 2. As shown in FIG. 4 is a block diagram showing part of the configuration of the image reading section 2. As shown in FIG. In FIG. 4, the transmission path of the electric signal corresponding to the read image from the CCD 26 to the image memory 36 is indicated by a solid line with an arrow.

As shown in FIGS. 1 and 3 , the ADF 1 includes a document placement portion 11 , a document transport path 12 , a plurality of transport rollers 13 , a document guide 14 and a paper ejection portion 15 .

A document to be transported is placed on the document placement section 11 . The document conveying path 12 is a document moving path from the document placing section 11 to the paper discharging section 15 . The document transport path 12 is formed inside the housing of the ADF 1 . The plurality of transport rollers 13 transport the document along the document transport path 12 by rotating with a rotational driving force supplied from a drive motor (not shown). The document guide 14 guides the document transported along the document transport path 12 to an image reading position P1 (see FIG. 3) by the image reading section 2 . The document that has passed through the reading position P<b>1 is discharged to the discharge section 15 .

The ADF 1 is provided so as to be openable and closable with respect to a document platen 21, which will be described later. The ADF 1 also serves as a document cover for the document placed on the document platen 21 .

As shown in FIGS. 1 and 2, the image reading section 2 includes a document platen 21, a reading unit 22, a mirror 23, a mirror 24, an optical lens 25, a CCD (Charge Coupled Device) 26, a reading control section 27, a first A sensor 28 , a second sensor 29 , a third sensor 30 and a fourth sensor 31 are provided.

The document platen 21 is used for placing a document. Document platen 21 is provided on the upper part of the housing of image forming apparatus 100 .

As shown in FIGS. 1 and 3, the platen 21 includes a first contact glass 211, a second contact glass 212, and a white reference plate 213. As shown in FIG. A document is placed on the first contact glass 211 . The second contact glass 212 is provided at a position facing the document guide 14 of the ADF 1 closed with respect to the document platen 21 . The white reference plate 213 is a flat plate-shaped member that is in surface contact with the first contact glass 211 and elongated in the main scanning direction (the direction perpendicular to the paper surface of FIG. 3). As shown in FIG. 3 , the white reference plate 213 is provided on the upper surface of the end of the first contact glass 211 facing the second contact glass 212 . White reference plate 213 has a predetermined colored region on the contact surface with first contact glass 211 . The colored area is an area colored with a predetermined reference color. For example, the reference color is white. The colored region is formed over the entire contact surface of the white reference plate 213 with the first contact glass 211 . The white reference plate 213 is an example of the reference portion of the present invention.

Image reading unit 2 can read an image from a document placed on first contact glass 211 . Further, the image reading section 2 can read an image from a document conveyed by the ADF 1 .

The reading unit 22 is provided below the document platen 21 . The reading unit 22 is configured to be movable in a sub-scanning direction D1 (see FIG. 1) perpendicular to the main scanning direction by a moving mechanism (not shown) having a drive motor.

As shown in FIG. 1, the reading unit 22 has a light source 221 and a mirror 222 . The light source 221 emits light directed toward the object to be read. Specifically, the light source 221 includes a plurality of white LEDs arranged along the main scanning direction. The light source 221 emits white light for one line in the main scanning direction toward the object to be read. The light emitted from the light source 221 is transmitted through the first contact glass 211 or the second contact glass 212 to irradiate the object to be read. The read target includes the document placed on the first contact glass 211 , the document conveyed by the ADF 1 , and the white reference plate 213 . The mirror 222 reflects the light emitted from the light source 221 and reflected by the object to be read to the mirror 23 . Note that the reading unit 22 may include a light guide member that refracts or reflects the light emitted from the light source 221 so as to direct the light toward the object to be read.

In image reading section 2 , when an image is read from a document placed on first contact glass 211 , reading unit 22 is moved below first contact glass 211 . As a result, the document placed on the first contact glass 211 is irradiated with the light emitted from the light source 221 . Further, the reading unit 22 is moved in the sub-scanning direction D1 by the moving mechanism. As a result, the light emitted from the light source 221 and applied to the document is scanned in the sub-scanning direction D1.

In the image reading section 2 , when an image is read from a document conveyed by the ADF 1 , the reading unit 22 is moved below the second contact glass 212 . Specifically, the reading unit 22 is moved to a position where the light emitted from the light source 221 passes through the reading position P1 (see FIG. 2). As a result, light emitted from the light source 221 is applied to the document conveyed through the reading position P1.

In the image reading section 2 , when an image is read from the white reference plate 213 , the reading unit 22 is moved below the white reference plate 213 . As a result, the colored region of the white reference plate 213 is irradiated with the light emitted from the light source 221 .

The mirror 23 reflects the light reflected by the mirror 222 of the reading unit 22 to the mirror 24 . The mirror 24 reflects the light reflected by the mirror 23 to the optical lens 25 . The optical lens 25 collects the light reflected by the mirror 24 and causes it to enter the CCD 26 .

The CCD 26 outputs an electrical signal based on the light reflected by the object to be read. Specifically, the CCD 26 is an image sensor having a plurality of photoelectric conversion elements arranged along the main scanning direction. The CCD 26 outputs an analog signal corresponding to the amount of light reflected by the object to be read. In the image reading unit 2 , the light emitted from the light source 221 and reflected by the object to be read enters the CCD 26 via the mirrors 222 , 23 , 24 and the optical lens 25 . As a result, an analog signal corresponding to the image to be read is output from the CCD 26 . An analog signal output from the CCD 26 is input to the reading control section 27 . CCD 26 is an example of the photoelectric conversion section of the present invention. Note that the photoelectric conversion unit of the present invention may be a CIS (Contact Image Sensor).

The reading control section 27 controls the operation of each section of the image reading section 2 . Further, the reading control unit 27 converts an analog electrical signal input from the CCD 26 into a digital electrical signal (image data).

As shown in FIG. 4, the reading controller 27 includes a CDS 32, an amplifier circuit 33, an ADC 34, a DSP 35, and an image memory 36. FIG.

The CDS 32 is an electric circuit that removes noise from analog signals input from the CCD 26 based on the correlated double sampling method or the like. CDS 32 outputs an analog signal from which noise has been removed.

The amplifier circuit 33 amplifies the analog signal input from the CDS 32 with the amplification factor set by the controller 7 . The amplifier circuit 33 outputs the amplified analog signal. The amplifier circuit 33 is an example of the signal amplifier of the present invention.

The ADC 34 is an AD converter that converts an analog signal input from the amplifier circuit 33 into a digital signal. The ADC 34 outputs a converted digital signal (image data).

The DSP 35 is a signal processor that performs various image processing on image data input from the ADC 34 . For example, the DSP 35 performs signal conversion processing to convert RGB data input from the ADC 34 into YUV data. The DSP 35 outputs image data after image processing.

The image memory 36 is a non-volatile storage device that stores image data output from the DSP 35 . The image data stored in the image memory 36 is used for print processing and the like executed using the image forming section 3 .

The first sensor 28 detects physical quantities that affect the electrical signal input to the amplifier circuit 33 . Specifically, the first sensor 28 detects the amount of emitted light from the light source 221 . For example, the first sensor 28 is a photosensor provided at a position capable of receiving light emitted from the light source 221 in the reading unit 22 . The first sensor 28 outputs an electrical signal corresponding to the amount of light received. The first sensor 28 is an example of the sensor of the present invention.

A second sensor 29 detects the physical quantity. Specifically, the second sensor 29 detects the ambient temperature. For example, the second sensor 29 is a temperature sensor that is provided inside the image reading section 2 and detects the internal temperature. The second sensor 29 outputs an electrical signal corresponding to the detected temperature. The environmental temperature may be the temperature outside the image forming apparatus 100 . The second sensor 29 is an example of the sensor of the present invention.

A third sensor 30 detects the physical quantity. Specifically, the third sensor 30 detects environmental humidity. For example, the third sensor 30 is a humidity sensor provided inside the image reading section 2 to detect the humidity inside. The third sensor 30 outputs an electric signal according to the detected humidity. The environmental humidity may be the humidity outside the image forming apparatus 100 . The third sensor 30 is an example of the sensor of the invention.

A fourth sensor 31 detects the physical quantity. Specifically, the fourth sensor 31 detects the temperature of the CCD 26 . For example, the fourth sensor 31 is a temperature sensor provided in contact with the CCD 26 . The fourth sensor 31 outputs an electrical signal corresponding to the detected temperature. The fourth sensor 31 is an example of the sensor of the invention.

Note that the image reading unit 2 may not include some of the first sensor 28 , the second sensor 29 , the third sensor 30 and the fourth sensor 31 .

By the way, in the image forming apparatus 100, AGC (Automatic Gain Control) processing for adjusting the amplification factor of the amplifier circuit 33 is executed based on the image data read from the white reference plate 213 when the apparatus is started.

For example, in the AGC process, the amplification factor is set to a predetermined initial value. Also, image data for one line is read from the white reference plate 213 using the image reading unit 2 . Then, the amplification factor is adjusted so that the density value of the pixel of the read image data is included in a predetermined reference range. Specifically, changing the amplification factor and reading the image data from the white reference plate 213 are repeated until the density value of the pixel of the read image data falls within the reference range.

Further, in order to shorten the time required for adjusting the amplification factor, until the elapsed time from the execution of the immediately preceding AGC processing passes a predetermined time, the execution result of the immediately preceding AGC processing is used. An image reading device that adjusts the amplification factor is known.

However, in the configuration in which the gain is adjusted using the execution result of the immediately preceding AGC processing, the current state of the apparatus cannot be reflected in the gain. Therefore, the image quality of the image data read by the image reading device may deteriorate.

On the other hand, in the image forming apparatus 100 according to the embodiment of the present invention, as described below, it is possible to shorten the time required for adjusting the amplification factor and to suppress deterioration in the image quality of the read image data. is.

[Configuration of control unit 7]
Next, the configuration of the control unit 7 will be described with reference to FIG.

As shown in FIG. 2, the control unit 7 includes a CPU 41, a ROM 42, and a RAM 43.

The CPU 41 is a processor that executes various kinds of arithmetic processing. The ROM 42 is a non-volatile storage device in which information such as control programs for causing the CPU 41 to execute various processes is stored in advance. The RAM 43 is a volatile or nonvolatile storage device used as a temporary storage memory (work area) for various processes executed by the CPU 41 .

The CPU 41 executes various control programs stored in the ROM 42 . Thereby, the control unit 7 controls the image forming apparatus 100 in an integrated manner. Note that the control unit 7 may be a control unit provided separately from the main control unit that controls the image forming apparatus 100 in an integrated manner. Also, the control unit 7 may be configured by an electronic circuit such as an integrated circuit (ASIC).

Also, as shown in FIG. 2 , the control unit 7 includes an acquisition processing unit 51 , a first adjustment processing unit 52 , a second adjustment processing unit 53 , a reconstruction processing unit 54 and a notification processing unit 55 .

Specifically, the ROM 42 of the control section 7 pre-stores an amplification factor adjustment program for causing the CPU 41 to function as each section described above. The CPU 41 functions as an acquisition processing unit 51, a first adjustment processing unit 52, a second adjustment processing unit 53, a reconstruction processing unit 54, and a notification processing unit 55 by executing the amplification factor adjustment program. The gain adjustment program may be recorded on a computer-readable recording medium such as a CD, DVD, or flash memory, read from the recording medium, and installed in the storage section 6 . Also, part or all of the above units may be configured by an electronic circuit such as an integrated circuit (ASIC).

The acquisition processing unit 51 uses the first sensor 28, the second sensor 29, the third sensor 30, and the fourth sensor 31 to obtain the plurality of physical quantities (the amount of light emitted from the light source 221, the environmental temperature, the environmental humidity, and temperature of the CCD 26).

The first adjustment processing section 52 adjusts the amplification factor of the amplification circuit 33 based on the plurality of physical quantities acquired by the acquisition processing section 51 .

Specifically, the first adjustment processing unit 52 adjusts the amplification factor using the learning model 61 (see FIG. 2). The learning model 61 is constructed by machine learning using teacher data 62 (see FIG. 2) in which the plurality of physical quantities and specific information used for adjusting the amplification factor are associated. For example, the specific information is numerical information indicating the amplification factor.

For example, in the image forming apparatus 100, the learning model 61 and the teacher data 62 are stored in the storage unit 6 in advance. The learning model 61 is a program that outputs the specific information according to the input of the plurality of physical quantities. For example, the learning model 61 is a neural network having an input layer to which the physical quantities are input and an output layer to which the specific information is output. The teacher data 62 is data used for constructing the learning model 61 . The storage unit 6 stores a plurality of teacher data 62 having different combinations of the physical quantities and the specific information.

Here, construction of the learning model 61 means adjusting parameters included in the learning model 61, such as weighting between neurons included in the neural network. Specifically, the parameter is adjusted so that the learning model 61 can output the specific information included in the teacher data 62 according to the input of the plurality of physical quantities included in the teacher data 62. . For example, the control unit 7 constructs the learning model 61 by machine learning using a plurality of teacher data 62 . Note that the learning model 61 constructed by machine learning using a plurality of teacher data 62 may be stored in advance in the storage unit 6 .

The first adjustment processing unit 52 inputs the plurality of physical quantities acquired by the acquisition processing unit 51 to the learning model 61, and based on the specific information output from the learning model 61 in response to the input, the amplification factor to adjust. Specifically, the first adjustment processing unit 52 adjusts the amplification factor so that the amplification factor corresponds to the specific information output from the learning model 61 .

Note that the learning model 61 and the teacher data 62 may be stored in a storage unit of an external information processing apparatus communicably connected to the image forming apparatus 100 . In this case, the first adjustment processing unit 52 may transmit the plurality of physical quantities acquired by the acquisition processing unit 51 to the external information processing device. Further, the external information processing apparatus acquires the specific information corresponding to the plurality of physical quantities transmitted from the image forming apparatus 100 using the learning model 61, and transmits the acquired specific information to the image forming apparatus 100. Just send it. Also, the first adjustment processing unit 52 may adjust the amplification factor based on the specific information transmitted from the external information processing device in response to transmission of the plurality of physical quantities.

Further, the first adjustment processing unit 52 may adjust the amplification factor using table data in which a plurality of the physical quantities and the specific information are associated with each other.

The second adjustment processor 53 adjusts the amplification factor based on the electrical signal output from the amplifier circuit 33 and corresponding to the light reflected by the white reference plate 213 . That is, the second adjustment processing section 53 executes the AGC processing.

For example, the second adjustment processing section 53 executes the AGC processing when a predetermined execution condition is satisfied.

For example, the execution condition is that a predetermined count value is a multiple of a predetermined first reference number of times. For example, the count value is the number of document reading times by the image reading section 2 . The execution condition may be that the count value exceeds a predetermined second reference number of times and is a multiple of the first reference number of times. Further, the count value may be the number of execution times of amplification factor adjustment processing, which will be described later.

The reconstruction processing unit 54 combines the adjustment result of the amplification factor by the second adjustment processing unit 53 with the plurality of physical quantities detected by the first sensor 28, the second sensor 29, the third sensor 30, and the fourth sensor 31. is used to reconstruct the learning model 61 .

Specifically, the reconstruction processing unit 54 causes the acquisition processing unit 51 to acquire the plurality of physical quantities when the AGC processing is performed by the second adjustment processing unit 53 . Further, the reconstruction processing unit 54 stores a combination of the plurality of physical quantities acquired by the acquisition processing unit 51 and the adjustment result of the amplification factor by executing the AGC process in the storage unit 6 as new teacher data 62. . Then, the reconstruction processing unit 54 reconstructs the learning model 61 by machine learning using a plurality of teacher data 62 including the newly added teacher data 62 . That is, the parameters included in the learning model 61 are readjusted.

When the amount of light emitted from the light source 221 detected by the first sensor 28 is less than a predetermined threshold value, the notification processing unit 55 notifies that effect.

For example, the notification processing unit 55 causes the operation display unit 5 to display a message indicating that the light source 221 has an abnormality when the amount of light emitted from the light source 221 acquired by the acquisition processing unit 51 is less than the threshold value.

Note that the control unit 7 does not have to include the second adjustment processing unit 53 and the reconstruction processing unit 54 . Also, the control unit 7 does not have to include the notification processing unit 55 .

[Amplification adjustment process]
Hereinafter, an example of the amplification factor adjustment method of the present invention will be described together with an example of the procedure of the amplification factor adjustment process executed by the control unit 7 in the image forming apparatus 100, with reference to FIG. Here, steps S11, S12, . For example, the amplification factor adjustment process is executed when the power of the image forming apparatus 100 is turned on and when the operation mode of the image forming apparatus 100 shifts from a power saving mode in which power consumption is lower than that of the normal mode to the normal mode. be.

<Step S11>
First, in step S11, the control unit 7 determines whether or not the execution condition is satisfied.

Here, when the control unit 7 determines that the execution condition is satisfied (Yes side of S11), the process proceeds to step S12. If the execution condition is not satisfied (No side of S11), the control unit 7 shifts the process to step S15.

<Step S12>
In step S<b>12 , the control unit 7 uses the first sensor 28 , the second sensor 29 , the third sensor 30 and the fourth sensor 31 to obtain the plurality of physical quantities. Here, the processing of step S<b>12 is executed by the acquisition processing section 51 of the control section 7 .

<Step S13>
At step S13, the control unit 7 executes the AGC process. Here, the process of step S<b>13 is executed by the second adjustment processing section 53 of the control section 7 .

<Step S14>
In step S14, the control unit 7 reconstructs the learning model 61 using the adjustment result of the amplification factor by the AGC process executed in step S13 and the plurality of physical quantities obtained in step S12. Here, the processing of step S14 is executed by the reconstruction processing unit 54 of the control unit 7. FIG.

Specifically, the control unit 7 saves the combination of the plurality of physical quantities acquired in step S12 and the adjustment result of the amplification factor by the AGC processing executed in step S13 as new teacher data 62 in the storage unit 6. Store. Then, the control unit 7 reconstructs the learning model 61 by machine learning using a plurality of teacher data 62 including the newly added teacher data 62 .

As a result, even if the relationship between the plurality of physical quantities and the adjustment result of the amplification factor by the AGC process changes with an increase in the usage time of the image forming apparatus 100, the change can be applied to the learning model 61. It is possible to reflect

<Step S15>
In step S15, the control unit 7 acquires the plurality of physical quantities, as in step S12. Here, the process of step S15 is an example of the acquisition step of the present invention, and is executed by the acquisition processing section 51 of the control section 7. FIG.

If the amount of light emitted from the light source 221 obtained in step S12 or step S15 is less than the threshold value, the control unit 7 notifies that effect. This processing is executed by the notification processing section 55 of the control section 7 .

<Step S16>
In step S16, the control unit 7 adjusts the amplification factor of the amplifier circuit 33 based on the plurality of physical quantities obtained in step S15. Here, the process of step S16 is an example of the adjustment step of the present invention, and is executed by the first adjustment processing section 52 of the control section 7 .

Specifically, the control unit 7 uses the learning model 61 (see FIG. 2) stored in the storage unit 6 to adjust the amplification factor. This makes it possible to adjust the amplification factor with high accuracy without executing the AGC process.

After executing the process of step S16, the control unit 7 reads image data from the white reference plate 213 using the image reading unit 2, and adjusts the amplification factor adjusted in step S16 based on the read image data. Further fine adjustments may be made.

Further, the teaching data 62 may not be stored in the storage unit 6 when the image forming apparatus 100 is shipped from the factory. In this case, in step S11, it may be determined that the execution condition is satisfied when the number of executions of the amplification factor adjustment process is equal to or less than a predetermined third reference number of times. Further, in step S14, the reconstruction (construction) of the learning model 61 may be suspended when the number of executions of the amplification factor adjustment process is less than the third reference number of times. Further, in step S14, the learning model 61 may be reconstructed (constructed) when the number of executions of the amplification factor adjustment processing reaches the third reference number of times. In other words, the teacher data 62 may be stored in the storage unit 6 from the time the user starts using the image forming apparatus 100 .

Also, the processes of steps S12, S13, and S14 may be executed when using a function different from the scan function. For example, the processes of steps S12, S13, and S14 may be executed while the print process using the image forming section 3 is being executed. In this case, in step S11, it may always be determined that the execution condition is not satisfied.

Further, the amplification factor adjustment process does not have to include the processes from step S11 to step S14. That is, the amplification factor adjustment process may be a process configured by steps S15 and S16.

Thus, in the image forming apparatus 100, the amplification factor of the amplification circuit 33 is adjusted based on the plurality of physical quantities detected by the plurality of sensors. As a result, the current state of the image forming apparatus 100 can be reflected in the amplification factor after adjustment. Therefore, it is possible to reduce the time required for adjusting the amplification factor and to suppress deterioration in image quality of the image data to be read, as compared with a configuration in which the amplification factor is adjusted using the execution result of the immediately preceding AGC process. It is possible.

1 ADF
2 image reading unit 3 image forming unit 4 paper feeding unit 5 operation display unit 6 storage unit 7 control unit 21 document table 22 reading unit 26 CCD
27 reading control unit 28 first sensor 29 second sensor 30 third sensor 31 fourth sensor 33 amplifier circuit 51 acquisition processing unit 52 first adjustment processing unit 53 second adjustment processing unit 54 reconstruction processing unit 55 notification processing unit 61 learning model 62 teacher data 100 image forming device 213 white reference plate 221 light source

Claims (7)

a light source that emits light directed toward an object to be read;
a photoelectric conversion unit that outputs an electrical signal based on the light reflected by the object to be read;
a signal amplifier that amplifies the electrical signal output from the photoelectric conversion unit;
a sensor that detects a physical quantity that affects the electrical signal input to the signal amplification unit;
a first adjustment processing unit that adjusts an amplification factor of the signal amplification unit based on the physical quantity detected by the sensor;
image reading device. comprising a plurality of said sensors corresponding to a plurality of said physical quantities,
the plurality of physical quantities include the light emission amount of the light source, the environmental temperature, the environmental humidity, and the temperature of the photoelectric conversion unit;
The first adjustment processing unit adjusts the amplification factor based on the plurality of physical quantities detected by the plurality of sensors.
The image reading device according to claim 1. The first adjustment processing unit adjusts the amplification factor using a learning model constructed by machine learning using teacher data in which a plurality of the physical quantities and specific information used for adjustment of the amplification factor are associated. do,
3. The image reading device according to claim 2. The reading target includes a reference portion of a predetermined reference color,
The image reading device is
a second adjustment processing unit that adjusts the amplification factor based on the electrical signal corresponding to the light reflected by the reference unit that is output from the signal amplification unit;
a reconstruction processing unit that reconstructs the learning model using the adjustment result of the amplification factor by the second adjustment processing unit and the plurality of physical quantities detected by the plurality of sensors;
The image reading device according to claim 3, comprising: A notification processing unit that notifies when the amount of emitted light of the light source detected by the sensor is less than a predetermined threshold value,
The image reading device according to any one of claims 2 to 4. an image reading device according to any one of claims 1 to 5;
an image forming unit that forms an image based on image data read by the image reading device;
An image forming apparatus comprising: A light source that emits light toward an object to be read, a photoelectric conversion unit that outputs an electrical signal based on the light reflected by the object to be read, and a signal amplifier that amplifies the electrical signal output from the photoelectric conversion unit. and a sensor that detects a physical quantity affecting the electrical signal input to the signal amplification unit, the amplification factor adjustment method being executed by an image reading device, comprising:
an acquisition step of acquiring the physical quantity using the sensor;
an adjustment step of adjusting an amplification factor of the signal amplification unit based on the physical quantity acquired by the acquisition step;
Amplification adjustment method including.

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