JP4749220B2 - Image information device - Google Patents

Description

  The present invention relates to an image information apparatus such as a digital copying machine or a printer, and more particularly to an image forming apparatus capable of aligning the writing position in the main scanning direction of a recording medium when an image is formed on a recording medium such as paper.

In an image forming apparatus capable of forming an image on both sides of a recording medium such as paper, when the writing position in the recording medium width direction (hereinafter referred to as the main scanning direction) is shifted, the vertical position that should be formed at the same position on the front and back sides. There is a problem that the lines do not overlap. Further, there is a problem that the image position in the main scanning direction does not match during continuous copying even when image formation is performed on one side.
The above-described problem is caused by a shift in the writing position in the main scanning direction (hereinafter referred to as main scanning resist). Therefore, at the time of factory shipment, the main scanning resist is adjusted so as to be at the same position with respect to the recording medium for each machine. However, variations occur due to a defective recording medium set in the paper feed tray or a skew inside the machine.

For this reason, the line-type photoelectric conversion means for simultaneously reading a plurality of pieces of pixel information continuous in the main scanning direction as a sensor for detecting an end (hereinafter referred to as an end) of the recording medium that travels is used as a recording medium conveyance path. The main scanning registration correction technique is provided which detects the amount of misalignment of the main scanning resist on the recording medium and adjusts the writing position on the recording medium for each recording medium.
The prior art disclosed in Patent Document 1 is a representative example of the main scanning resist correction technique as described above, and a non-contact optical sensor in which a plurality of light emitting elements and a plurality of light receiving elements are arranged is orthogonal to the conveyance direction of the recording medium. The position of the recording medium is detected, and the position of the recording medium is detected, and the image writing position on the recording medium is corrected. In this prior art, the light emission quantity of the light emitting element can be adjusted at the time of initial adjustment in order to correct the output variation of the plurality of light receiving elements.
JP 2003-223088 A

As described above, in the prior art disclosed in Patent Document 1, the light emission amount of the light emitting element can be adjusted in order to correct the output variation of the plurality of light receiving elements, but the control of the light emission amount according to the recording medium is possible. I can't. Factors that cause variations in the output of the light receiving element include the initial light intensity variation of the light emitting element, the short-term fluctuation and life of the light intensity, the sensitivity variation of the light receiving element, and the density of the recording medium used as a reference when adjusting the light intensity. There is also an influence. The same type of recording medium is not always used, and the density of white paper varies depending on the type. Also, colored paper may be used as a recording medium, and the output level of the light receiving element varies depending on the emission wavelength of the LED light source and the spectral reflectance characteristics of the colored paper.
The present invention is intended to solve such a problem of the prior art, and specifically provides an image forming apparatus capable of obtaining an appropriate photoelectric conversion output for all recording media. Objective.

In order to solve the above-described problem, the image information apparatus according to claim 1 is an image information apparatus including an image forming apparatus that forms an image on a recording medium, wherein a plurality of pixel photoelectric conversion elements are transported through the recording medium. In order to identify the edge of the recording medium from the photoelectric conversion means for detecting the edge of the recording medium arranged so as to be arranged orthogonally to the recording medium, and the analog image signal output from the photoelectric conversion means for detecting the edge of the recording medium and binarizing means for binary digitization as compared to the set comparison signal, the edge detection means for detecting the end of the recording medium using the binarized data obtained by said binarizing means multi-value unit that multi-level digitization in order to compensate for the difference in density and the spectral reflectance characteristic of the recording medium to be used as a reference recording medium an analog image signal output from the recording medium position detecting photoelectric conversion means and, the multi-valued catheter By dividing the output level of the previous SL reference recording medium obtained at the output level of the recording medium to the use obtained by the multilevel means by illumination light used in the recording medium position detecting photoelectric conversion means A light amount adjustment value calculating means for calculating a light amount adjustment value.

The image information apparatus according to claim 2 further includes: a document reading photoelectric conversion unit that reads an image on a document; and a multi-value conversion unit that performs multi-value digitization of an analog image signal output from the document reading photoelectric conversion unit. In an image information apparatus including an image reading apparatus that reads an original image and an image forming apparatus that forms an image on a recording medium, the plurality of pixel photoelectric conversion elements are arranged orthogonally to the conveyance path of the recording medium And a comparison signal set to identify an end of the recording medium from an analog image signal output from the recording medium end detection photoelectric conversion means. using a binarizing means for binary digitization by comparing the edge detection means for detecting the end of the recording medium using the binary data obtained by the binarizing means, the reference recording medium The output of the recording medium to the use of resulting output level of the reference recording medium obtained by the multi-value means by said multi-value means for correcting the difference between the concentration and the spectral reflectance characteristic of the recording medium that by dividing by the level, and a light intensity adjustment value calculating means for calculating a light intensity adjustment value of the illumination light used in the recording medium position detecting photoelectric conversion means.

  According to the present invention, the light amount adjustment value of the illumination light used in the photoelectric conversion means for detecting the edge of the recording medium can be calculated according to the recording medium to be used, so that an appropriate photoelectric conversion output can be obtained for all the recording media. Therefore, the edge detection error can be reduced for all types of recording media, and the writing position in the main scanning direction can be aligned.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the components, types, combinations, shapes, relative positions, and the like described in this embodiment are not merely intended to limit the scope of this description unless otherwise specified, but are merely illustrative examples. . The embodiment of the image information apparatus described here is a digital copying machine provided with an image reading apparatus and an image forming apparatus. However, a general description of the image forming apparatus will be omitted, and FIG. 1 will be referred to hereinafter. The image reading apparatus will be described below.
As shown in FIG. 1, this image reading apparatus conveys a contact glass 101 on which an original 105 is mounted, a contact glass 102 for sheet-through reading, a reference white plate 103 for white level adjustment and shading data generation, and an original 106. Document transport roller 104, light source 107 for irradiating the document, first mirror 108, first carriage 109 on which light source 107 and first mirror 108 are mounted, second mirror 110, third mirror 111, second mirror 110 and A second carriage 112 on which the third mirror 111 is mounted, a CCD image sensor 114 (corresponding to the photoelectric conversion means for reading a document in the claims), a lens unit 113 that forms a reduced image on the CCD image sensor 114, a CCD image Image reading circuit base equipped with sensor 114 115, the image data processing unit 117, the scanner drive motor (not shown) for driving the carriage 109, 112 includes a home position sensor, and original detection sensor.

In the configuration described above, when the original 105 is mounted on the contact glass 101, the light source 107 is turned on, and the original 105 is read by moving and scanning the first carriage 109 and the second carriage 112 to the right by the scanner motor. Then, the light source 107 is turned on while the first carriage 109 and the second carriage 112 are stopped, and the original 106 conveyed by the original conveying roller 104 is read by irradiating it through the contact glass 102 for reading through the sheet. A reading method can be selected.
Among these reading methods, when scanning a document by scanning the carriages 109 and 112, data read from the reference white plate 103 is acquired prior to reading the document, and shading correction data is generated and stored in the memory. The image data read from the document 105 is normalized using the shading correction data, thereby correcting the light amount distribution unevenness and the sensitivity unevenness of the CCD image sensor 114 in the apparatus.

In the case of sheet-through reading in which the original 106 is conveyed and image data is read while the carriages 109 and 112 are stopped, the first carriage 109 is moved below the reference white plate 103 prior to reading the original 106. Then, after generating shading correction data and returning to the sheet-through reading position, the conveyance of the original 106 is started and the original reading operation is started.
In the digital copying machine according to an embodiment of the present invention, control for aligning the writing position on the surface of the recording medium is performed by detecting an end in the main scanning direction of the recording medium such as paper. The position at which the end of the recording medium in the main scanning direction is detected in the recording medium conveyance direction (sub-scanning direction) differs depending on the system. In this embodiment, however, detection is performed within the hatched range shown in FIG. As shown in FIG. 2, the line-type photoelectric converter is installed such that its longitudinal direction (arrangement direction of a plurality of pixel photoelectric conversion elements corresponding to a plurality of pixels) is aligned with a main scanning direction orthogonal to the recording medium conveyance direction. . For example, a contact image sensor (CIS) is used as the photoelectric converter.

Hereinafter, each embodiment of the present invention will be described.
FIG. 3 shows a configuration of a contact image sensor (hereinafter referred to as CIS) used as a photoelectric conversion means for detecting a recording medium edge in this embodiment, and FIG. 4 shows a configuration of a recording medium edge detection circuit. The CIS and recording medium detection circuit will be described below with reference to FIGS.
As shown in FIG. 3, the CIS 1 includes a light receiving element portion 11, a shift register portion 12, and a light emitting diode (hereinafter referred to as LED) group 13 that is an illumination unit. The light quantity of the LED group 13 is adjusted by a CIS / LED signal output from the LED current control circuit 8 (see FIG. 4). The CIS / LED signal is, for example, a PWM (pulse width modulation) signal. In this case, the LED / PWM signal, which is a pulse signal having a predetermined period, is supplied from the CIS control circuit 5, and the LED current control circuit 8 receives the signal. The CIS / LED signal is generated by switching the transistor incorporated in the. The amount of light can be adjusted by changing the duty of the LED / PWM signal.

On the other hand, when constant current control is used instead of PWM control, for example, the circuit shown in FIG. In this case as well, the light quantity can be adjusted by changing the duty of the LED / PWM signal.
An analog signal from the CIS 1 is converted into binary digital data by the comparator 2. In this conversion process, if the CIS output signal level is small, it is easily affected by noise and the like. Further, if the degree becomes severe, the comparison voltage (TH voltage) of the comparator 2 is not reached and the end of the recording medium is not detected (see FIG. 6A), or an end detection error occurs (FIG. 6 ( b)). Therefore, in this embodiment, the light amount is adjusted so that the CIS output signal level when reading from the reference recording medium becomes a predetermined level. Note that the variation factors of the CIS output signal level at this time include the initial variation of the light amount of the LED group 13, the short-term variation of the light amount, the light amount life, the CIS sensitivity variation, and the influence of the density variation of the white level of the recording medium. The same type of recording medium is not always used, and even a blank paper has a different density depending on the type, so the CIS output level is different. Also, colored paper may be used as a recording medium, and the CIS output level varies depending on the emission wavelength of the LED light source and the spectral reflectance characteristics of the colored paper.

Hereinafter, the recording medium edge detection circuit shown in FIG. 4 will be described.
As shown in the figure, the CIS control circuit 5 is controlled by the CPU 4 to send the CIS / CLK signal and the CIS / SH signal to the CIS 1 and the recording medium edge detection circuit 3 (corresponding to the edge detection means in the claims). Supply. CIS · CLK is a system clock for CIS1 and the recording medium edge detection circuit 3. The recording medium edge detection circuit 3 latches data from CIS1 with this CIS · CLK signal. On the other hand, the CIS / SH signal is used to reset an internal counter.
The CIS control circuit 5 supplies a COMP / PWM signal to the TH adjustment circuit 6. This TH adjustment circuit 6 has an integrating circuit inside, generates a DC voltage from the COMP / PWM signal, and supplies a reference comparison voltage to the comparator 2. Therefore, the comparison voltage can be adjusted by changing the duty of the COMP / PWM signal. Further, the CIS control circuit 5 supplies the LED / PWM signal to the LED current control circuit 8. In this embodiment, the binarization means described in the claims is realized by the comparator 2 and the TH adjustment circuit 6.

  With such a configuration, the comparator 2 converts the analog signal into a binary digital signal by comparing the analog signal from the CIS 1 with a comparison voltage (TH voltage; threshold voltage). Upon receiving this digital signal, the recording medium edge detection circuit 3 generates a gate signal indicating the recording medium edge from the binarized digital signal, and the CPU 4 calculates the difference between the gate signal position and the reference position. A count value is generated, and the count value is set in the recording medium write position control circuit 7. Thus, the recording medium writing position control circuit 7 can correct the image writing position on the recording medium.

FIG. 7 is a timing chart showing the operation of the recording medium edge detection circuit 3. Hereinafter, the operation of the recording medium edge detection circuit 3 will be described with reference to FIG.
In the example shown in FIG. 7, in order to avoid erroneous recognition due to contamination of the recording medium, a cis / din signal that is a binarized signal output from the comparator 2 (“High” output is output when the recording medium exists). When the “High” level is continuously obtained for four pixels, it is determined as the end of the recording medium, and the P · EDGE signal is set to the “Low” level (here, the “Low” level is output when the recording medium is detected). Level). FIG. 7 shows that the P · EDGE signal does not become the “Low” level in the case of three consecutive pixels but becomes the “Low” level in four consecutive pixels. The P • EDGE signal is reset when the CIS • SH signal becomes “High” level.

  The reference number of pixels from the CIS / SH signal until the P / EDGE signal becomes “Low” level is determined in advance, and the value is stored in a memory (not shown) at the time of factory shipment, for example. At the time of printing, the CPU 4 detects the number of pixels from the CIS / SH signal to the P / EDGE signal at the “Low” level for each recording medium, and calculates a difference with respect to the reference number of pixels. The CPU 4 uses the difference as a deviation of the recording medium during conveyance, and changes the writing start position in a direction to correct the deviation. Note that the difference may be outside the expected range. For example, system factors or the presence of dust larger than the expected size may be considered. In this case, an error signal is output as an abnormality. Further, the CPU 4 calculates an average value of the number of pixels from the CIS / SH signal for a plurality of lines until the P / EDGE signal becomes the “Low” level for the purpose of avoiding erroneous detection, and finally ends the recording medium. Calculate the position.

  FIG. 8 shows an operation flow during light amount adjustment. In this light amount adjustment, a reference recording medium is used, and first, the LED current of CIS 1 is maximized to determine whether or not the P · EDGE signal is at the “Low” level over the target number of pixels (P · EDGE = “Low”). "The level is the level when the presence of a recording medium is detected." Then, the CIS output level is lowered by decreasing the LED current. Even if one pixel is the "Low" level until then, the "High" level In this case, it is determined that the image peak level at that time is in the vicinity of the comparison voltage of the comparator 2, and the LED current is adjusted so that the output is α times the output at that time, and the adjustment is completed. The coefficient α is a value determined from the evaluation result of the light quantity deterioration characteristic and detection accuracy of CIS1.

The operation flow for determining the reference recording medium output level (LED current determination) will be described below with reference to FIG.
In this embodiment, after the power is turned on, when the light amount adjustment mode is set by a key operation or the like, the reference recording medium is transported from the paper feed tray to the position of CIS1 and stopped under the control of the system control unit 131. In this state, the CPU 4 sets the current setting value A of the LED current to the maximum value by the CIS control circuit 5, and turns on the LED group 13 in the CIS 1 (step 1).
In this state, the CPU 4 determines whether or not the “Low” width of the P · EDGE signal is equal to or greater than a predetermined number of pixels (step 2). If the number of pixels is greater than or equal to the predetermined number (Yes in Step 2), the current setting value A is set to “Down” by the CIS control circuit 5 to reduce the LED current by a predetermined amount (Step 3). To reduce the amount of light. The predetermined amount is determined from CIS characteristic evaluation at the time of system design.

Subsequently, the CPU 4 determines whether or not even one pixel among the pixels within the “Low” width in the P · EDGE signal has changed to the “High” level (step 4). No in step 4) Return to step 3 to further reduce the amount of light. Even one pixel is repeated until a pixel that changes to the “High” level appears. Thus, when a “High” level pixel is generated (Yes in step 4), a value obtained by multiplying the current set value A by α is determined as an LED current value when the reference recording medium is used (step 5). This α times becomes an upper voltage margin for the comparison voltage of the comparator 2.
Next, it is determined whether or not A × α exceeds a predetermined maximum current (step 6). If it does not exceed (Yes in step 6), the light amount adjustment is terminated at this point, and the determined A × α is determined. Is stored in a reference medium output level holding unit 123 described later as a value corresponding to the reference medium output level (step 7).
On the other hand, if it is determined in step 2 that the number of pixels is not more than a predetermined number (No in step 2), or if the maximum current is exceeded in step 6, a light amount adjustment error is determined (step 8). In the above description, the current setting value A is the ratio of the “High” level width of the LED / PWM signal.

As described above, the same type of recording medium is not always used, and the CIS output level varies depending on the type of recording medium. Therefore, in this embodiment, a standard medium output level is obtained for various recording media, a light amount correction value is obtained by obtaining a ratio to the reference medium output level, and an LED current applied to the LED group 13 is changed for each recording medium. As a result, the medium output level is made the same.
In order to obtain the ratio of the output levels described above, it is necessary to obtain a CIS output level that has been digitized in multiple values. In this embodiment, this is performed using the CCD image sensor 114 or the original reading circuit constituting the image reading apparatus described above. This is because providing a separate reading circuit including multi-value digitizing means for CIS1 increases the cost accordingly. However, in this embodiment, the total spectral characteristic determined by the spectral sensitivity characteristic of the CIS 1 and the spectral intensity of the LED group 13 that is the illumination means, and the spectral sensitivity characteristic of the CCD image sensor 114 that is the photoelectric conversion means for document reading The total spectral characteristic determined by the spectral intensity of the light source 107 that is the illumination means is made to match or be close to the characteristic. The size of the photoelectric conversion output is mainly determined by the spectral reflectance of the recording medium, the spectral intensity characteristics of the illumination means, the spectral sensitivity characteristics of the photoelectric converter, etc. This is because ΣG (λ) P (λ), which is generally determined from the spectral sensitivity characteristic P (λ) of the photoelectric conversion means and the spectral intensity characteristic G (λ) of the illumination means, is different unless it is designed to match.
A plurality of CCD image sensors 114 having different spectral sensitivity characteristics may be provided, and a CCD image sensor 114 having characteristics that match or are close to the spectral sensitivity characteristics of CIS 1 may be selected. For example, a bar having a plurality of CCD image sensors 114 is selected by sliding on the image reading circuit board 115. It should be noted that a multi-value digitizing means may be provided separately from the document reading circuit, and input from the CIS 1 to the multi-value digitizing means. In such a configuration, the above-described total spectral characteristic adjustment is not necessary. .

FIG. 9 shows the configuration of the document reading circuit 116 and the image data processing unit 117 provided on the document reading circuit board 115. The input to the document reading circuit is from the CCD image sensor 114.
As shown in the figure, the document reading circuit 116 includes a sample hold circuit 201, a black level correction circuit 202, an analog signal amplification circuit 203, an AD conversion circuit 204 (corresponding to the multi-value conversion means described in claims), and the like.
With this configuration, in the document reading circuit 116, the sample hold circuit 201 samples the analog image signal input from the CCD image sensor 114 by the sample pulse input from the timing generator (not shown), and the input level. And the black level correction circuit 202 corrects the variation in the dark output level of the CCD image sensor 114, and the amplification circuit 203 determines a predetermined level at which the reference white plate level is determined. The signal is amplified with a gain such that the AD conversion circuit 204 converts the signal into 10-bit digital image data.
The digital image data obtained in this way is output to the shading correction circuit 205, and the shading correction circuit 205 uses the reference white plate data to detect variations in sensitivity of the CCD image sensor 114 and uneven distribution of light in the illumination optical system included in the image data. The image processing circuit 206 performs various image processing on the corrected image data.

The above-described image path is a main path of the document reading processing system. In addition to this image path, the image data after shading is output to the light amount correction value calculation circuit 122 (corresponding to the light amount adjustment value calculation means in the claims). The
The light amount correction value calculation circuit 122 acquires the output level of the reference recording medium (hereinafter referred to as the reference recording medium output level) in advance through this path, and stores it in the reference recording medium output level holding unit 123. In other words, a reference recording medium output level is stored in the reference recording medium output level holding unit 123 by setting a blank reference recording medium on, for example, the contact glass 101 and causing the CCD 114 to read the reference recording medium.
Thereafter, when performing light amount correction of the LED group 13 in the CIS 1 according to the recording medium (for example, paper) to be used, the light amount correction value calculation circuit 122 receives a light amount correction calculation instruction from the operation unit 121 via the system control unit 131. When the image data read from the blank recording medium set on the contact glass 101 is passed from the shading correction circuit 205, the light amount correction value is calculated. That is, the light amount correction value is calculated from the following calculation formula using the recording medium output level passed at this time and the reference recording medium output level stored in the reference recording medium output level holding unit 123 in advance.
Light intensity correction value = (reference recording medium output level) / (recording medium output level)
Subsequently, the light amount correction value calculation circuit 122 acquires the current set value A × α of the reference recording medium from the reference recording medium output level holding unit 123, multiplies the acquired value by the obtained light amount correction value, and calculates the product value. The CIS control circuit 5 obtains the “High” width of the LED / PWM signal.
In the above calculation formula, the LED current that determines the amount of light of the recording medium is calculated from the ratio to the reference recording medium. Therefore, the amount of light is optimal for the recording medium, and the CIS output is compared with the comparator 2 by such correction. It is possible to prevent a problem that the voltage is lower than the voltage.
Thus, according to this embodiment, the edge detection error can be reduced for all types of recording media, and the writing position in the main scanning direction can be aligned.

FIG. 10 is an explanatory diagram showing the operation unit of the second embodiment, and FIG. 11 is a block diagram showing the configuration of the document reading circuit 116 and the image data processing unit 117a. Hereinafter, this embodiment will be described with reference to FIGS. 10 and 11. In FIG. 10, the display panel shows a display example when the paper feed tray is selected, and FIG. Yes) is added.
With this configuration, the user selects one paper feed tray to be used from among a plurality of paper feed trays displayed on the display panel in the operation unit 121, and is then stored in the paper feed tray to be used. One of the blank recording media is set on the contact glass 101, for example, and the START button in the operation unit 121 is pressed. As a result, the system control unit 131 transmits the paper feed tray selection information to the light amount correction value holding circuit 124 and stores it in the light amount correction value holding circuit 124. The light quantity correction value holding circuit 124 can hold a different quantity of light quantity correction value for each paper feed tray.
Next, the blank recording medium used is read, and the light quantity correction value described in the first embodiment is calculated using the obtained recording medium output level. Accordingly, the system control unit 131 stores the calculated light amount correction value in the light amount correction value holding circuit 124 in association with the paper feed tray selection information stored in the light amount correction value holding circuit 124.

When the user forms an image on a recording medium after calculating and setting the light amount correction value for each paper feed tray, the paper feed tray is automatically selected based on, for example, copy document size information, and the system control unit 131 transmits the paper feed tray selection information to the light quantity correction value holding circuit 124. Then, the light quantity correction value holding circuit 124 transmits the light quantity correction value associated with the received paper feed tray selection information to the CIS control circuit 5. As a result, the CIS control circuit 5 switches the duty of the LED / PWM signal for each paper feed tray using the received light quantity correction value. As a result, the light emission quantity of the LED group 13 is a light emission suitable for the selected storage recording medium. Switch to light intensity.
Thus, in this embodiment, the same effect as in the first embodiment can be obtained without bothering the user.
Instead of holding the light amount correction value in association with the paper feed tray, it is also possible to hold the light amount correction value in association with the type of recording medium. In this case, the recording medium to be used is instructed using a display panel in the operation unit 121, for example.

1 is an explanatory diagram illustrating a configuration of an image reading apparatus in a digital copying machine as an embodiment of the present invention. FIG. It is explanatory drawing which shows the installation state of a line type photoelectric converter as one Embodiment of this invention. It is a figure which shows the structure of the contact | adherence image sensor as the 1st Embodiment of this invention. 1 is a block diagram showing a configuration of a recording medium edge detection circuit as a first embodiment of the present invention. FIG. 1 is a block diagram illustrating a configuration of a main part of a recording medium edge detection circuit as a first embodiment of the present invention. FIG. It is explanatory drawing which concerns on the recording medium edge part detection of the 1st Embodiment of this invention. 3 is a timing chart illustrating an operation of a recording medium edge detection circuit according to the first exemplary embodiment of the present invention. It is a flowchart which shows the operation | movement flow at the time of light quantity adjustment as the 1st Embodiment of this invention. 1 is a block diagram illustrating a configuration of a document reading circuit and an image data processing unit as a first embodiment of the present invention. FIG. It is explanatory drawing which shows the structure of the operation part as the 2nd Embodiment of this invention. It is a block diagram which shows the structure of a document reading circuit and an image data processing part as the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contact | adherence image sensor 2 Comparator 3 Recording-medium edge detection circuit 4 CPU
DESCRIPTION OF SYMBOLS 5 CIS control circuit 6 TH adjustment circuit 7 Recording medium write-out position control circuit 8 LED current control circuit 13 Light emitting diode group 114 CCD image sensor 116 Original reading circuit 117 Data processing part 121 Operation part 122 Light quantity correction value calculation circuit 123 Reference recording medium output Level holding unit 124 Light amount correction value holding circuit

Claims (2)

In an image information apparatus having an image forming apparatus for forming an image on a recording medium,
A plurality of pixel photoelectric conversion elements arranged so as to be orthogonal to the recording medium conveyance path;
And binarizing means for binary digitization as compared to the set comparison signal to identify the end of the recording medium output analog image signal from the recording medium position detecting photoelectric conversion means,
Edge detection means for detecting the edge of the recording medium using the binarized data obtained by the binarization means ;
Multi-value conversion means for converting the analog image signal output from the recording medium edge detection photoelectric conversion means into multi-value digital data in order to correct a difference in density and spectral reflectance characteristics between a reference recording medium and a recording medium to be used ; ,
By dividing the output level of the previous SL reference recording medium obtained by the multi-value conversion unit at a power level of the recording medium to the use obtained by the multi-value conversion means, said recording medium position detecting photoelectric conversion means A light amount adjustment value calculating means for calculating a light amount adjustment value of the illumination light used in
An image information device comprising: An image reading apparatus for reading an original image, comprising: an original reading photoelectric conversion means for reading an image on the original; and a multi-value conversion means for performing multi-value digitization of an analog image signal output from the original reading photoelectric conversion means. ,
An image forming apparatus for forming an image on a recording medium;
In an image information device comprising:
A plurality of pixel photoelectric conversion elements arranged so as to be orthogonal to the recording medium conveyance path;
And binarizing means for binary digitization as compared to the set comparison signal to identify the end of the recording medium output analog image signal from the recording medium position detecting photoelectric conversion means,
Edge detection means for detecting the edge of the recording medium using the binarized data obtained by the binarization means ;
The use resulting output level of the reference recording medium obtained by the multi-value conversion means for correcting a difference in concentration and spectral reflectance characteristic of the recording medium to be used as a reference recording medium by said multi-value conversion means A light amount adjustment value calculating means for calculating a light amount adjustment value of illumination light used in the photoelectric conversion means for detecting the edge of the recording medium by dividing by the output level of the recording medium ;
An image information device comprising:

Images