JP4700866B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a laser printer, and more particularly to a multipurpose sensor thereof.
[0002]
[Prior art]
An image forming apparatus such as a copying machine or a laser printer conveys in a predetermined direction a latent image carrier that carries a latent image, a developing device that develops the latent image by applying a developer to the latent image carrier. A transfer unit that transfers the developer image by the developing device to the recording material to be recorded, and the recording material that has received the transfer of the developer image by the transfer unit is heated and pressed under predetermined fixing processing conditions. A fixing device for fixing the developer image on the recording material;
[0003]
Conventionally, in such an image forming apparatus, in order to obtain a stable image quality independent of the type of recording paper as a recording material (hereinafter also referred to as paper type), for example, recording is performed on an operation panel or the like provided in the main body of the image forming apparatus. The user sets the paper type and controls the setting of the fixing processing conditions (for example, the fixing temperature and the conveyance speed of the recording paper passing through the fixing device), development, and transfer conditions according to the setting.
[0004]
This is particularly a problem of image quality degradation caused by changes in the transferability of the recording agent onto the recording paper or changes in the fixing property of the recording agent due to the surface properties of the recording material (the paper fiber roughness). It is the means used to eliminate.
[0005]
In addition, in order to improve the image quality (transparency improvement) of the OHT sheet, whether or not the recording sheet is an OHT sheet is automatically detected by a transmission type sensor provided in advance in the image forming apparatus, and light is transmitted through the recording sheet. In this case, it is determined that the sheet is an OHT sheet, and when light is not transmitted through the recording paper, it is determined as plain paper, and control is performed so as to set the fixing temperature or the recording paper conveyance speed according to the determination result.
[0006]
In the case of an OHT sheet, this is a control performed for the purpose of changing the fixing processing conditions to improve the fixability of the developer and improve the permeability of the developer.
[0007]
In an image forming apparatus such as a color copying machine or a color laser printer that includes a plurality of color developers, a latent image carrier for each color, and transfers the developer image on a recording sheet, an image of each color In order to prevent misregistration and improve image quality, each color developer image is previously transferred onto an electrostatic transfer belt or an intermediate transfer member, and a developer for each color is detected by a color misregistration detection sensor including an LED and a photodiode. Color misregistration control is performed to detect the color misregistration difference of the image and control the timing of forming the latent image on the latent image carrier so as to eliminate the color misregistration difference.
[0008]
In addition, in order to stably control the density of the developer image transferred onto the recording paper at a desired value and to stabilize the image quality, conventionally, a specific developer on the electrostatic transfer belt or intermediate transfer member has been conventionally used. The image is transferred, this image is read by a density detection sensor comprising an LED and a photodiode, and density control is performed so that the developer can be developed on the latent image carrier at a desired development density.
[0009]
[Problems to be solved by the invention]
However, the above-described conventional image forming apparatus has the following problems.
In an image forming apparatus, the size and type of recording paper are set by a user on an operation panel or the like provided on the main body, and fixing processing conditions (for example, fixing temperature and conveyance of recording paper passing through the fixing device) are set according to the settings. Speed) and transfer conditions are set to maintain high image quality, increasing the burden on the user.
[0010]
In recent years, the number of paper types handled has increased, and it has become impossible to cover all paper types only with the setting mode prepared in advance. As a result, there has been a problem that the setting of fixing processing conditions is not well determined and the fixing property is deteriorated. In particular, in rough paper or the like where the paper fibers on the surface of the recording paper are rough, fixing properties are deteriorated unless the toner on the recording paper is sufficiently fused.
[0011]
In the image forming apparatus corresponding to the OHT sheet, the plain paper and the OHT sheet are discriminated. In the case of the OHT sheet, the time for the OHT sheet to pass through the fixing device is set longer than that of the plain paper, and the developer on the OHT sheet. This improves the fusing and improves the fixability and permeability. This is a measure for preventing the developer from being sufficiently fixed on the OHT sheet due to the smooth surface of the OHT sheet, and the OHT permeability being remarkably lowered due to irregular reflection of the developer.
[0012]
Conventionally, in order to solve this problem, it is necessary to provide a dedicated sensor for determining OHT, so that the cost performance of the image forming apparatus is poor.
[0013]
In an image forming apparatus that requires density control of a developer image on an electrostatic transfer belt or an intermediate transfer body, it is necessary to provide a sensor dedicated to developer density detection, so that the cost performance of the image forming apparatus is poor.
[0014]
In an image forming apparatus that requires color misregistration control, it is necessary to provide a sensor dedicated to color misregistration detection, so the cost performance of the image forming apparatus is poor.
[0015]
In an image forming apparatus in which the distance between the fixing unit and the electrostatic transfer belt or the intermediate transfer member is short, the peripheral speed of the electrostatic transfer belt or the intermediate transfer member changes due to the heat generated by the fixing unit. There is a problem that color misregistration deteriorates in a color image forming apparatus that transfers images in a superimposed manner.
[0016]
In order to solve the above problem, conventionally, a roller that follows an electrostatic transfer belt or an intermediate transfer member is disposed, and the peripheral speed of the electrostatic transfer belt or the intermediate transfer member is detected by detecting the number of rotations of the roller. However, since a sensor dedicated to peripheral speed detection is used, the cost performance of the image forming apparatus is poor.
[0017]
  The present invention has been made under such circumstances, and image formation capable of obtaining a good image while improving both usability and cost performance by utilizing one video reading sensor for multiple purposes. DressPlaceTo provideTaskIt is what.
[0018]
[Means for Solving the Problems]
  In order to solve the above problems, in the present invention, an image forming apparatus is configured as follows.
  (1) an image carrier, a developing means for developing the latent image by applying a developer to the latent image formed on the image carrier, and a developer image developed by the developing means as a recording material In an image forming apparatus comprising: transfer means for transferring; and fixing means for fixing the developer image to the recording material by heating and pressurizing the recording material on which the developer image has been transferred by the transfer means.
  A light irradiating means for irradiating light on the surface of the recording material; a reading means for reading light emitted from the light irradiating means and reflected by the surface of the recording material as an image; and a plurality of images read by the reading means. Computing means for computing using an algorithm,
  The plurality of algorithms include a first algorithm for calculating data indicating the surface smoothness of the recording material using the image of the surface of the recording material read by the reading unit, and a leading end of the recording material read by the reading unit. A second algorithm for calculating data indicating the thickness of the recording material using the image of the recording portion, and data indicating the conveyance speed of the recording material using a plurality of images of the surface of the recording material read by the reading means A third algorithm,
  The calculating means is based on data indicating the surface smoothness of the recording material calculated using the first algorithm and data indicating the thickness of the recording material calculated using the second algorithm. And an image forming apparatus that controls the recording material conveyance speed to be constant based on data indicating the recording material conveyance speed calculated using the third algorithm..
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to examples of image forming apparatuses. The present invention is not limited to the form of the apparatus, and can be implemented in the form of a method supported by the description of the embodiments.
[0031]
【Example】
Example 1
FIG. 1 is a cross-sectional view illustrating a schematic configuration of an “image forming apparatus” according to a first embodiment.
[0032]
As shown in FIG. 1, the image forming apparatus 101 includes a cassette for storing recording paper 102, a paper feed roller 103, an electrostatic transfer belt driving roller 104, an electrostatic transfer belt 105, and a photosensitive drum 106 to a latent image carrier. 109, yellow, magenta, cyan and black photosensitive drums, transfer rollers 110 to 113 for applying a transfer bias, developing rollers 114 to 117 for applying a developing bias, optical units 118 to 121, and fixing as a fixing device. The unit 122 and the like are included.
[0033]
In the image forming apparatus 101, a toner image, which is a developer image of each color of yellow, magenta, cyan, and black, is transferred onto a recording sheet by using an electrophotographic process, and the recording sheet is transferred to a predetermined temperature by a fixing unit 122. The toner image is fixed on the recording paper by heating and pressurizing at the above.
[0034]
Each color optical unit 118 to 121 is configured to form a latent image by exposing and scanning the surface of each photosensitive drum 106 to 109 with a laser beam, and a series of these image forming operations is predetermined on the recording paper to be conveyed. The scanning is controlled in synchronization so that the image is transferred from the position. The latent images formed on the surfaces of the photosensitive drums 106 to 109 are visualized as toner images by toners as developing agents of the respective colors by the developing devices 114 to 117 provided in the cartridge.
[0035]
In addition, the image forming apparatus 101 includes a paper feed motor (not shown) that feeds and conveys recording paper, a transfer belt drive motor (not shown) that drives the transfer belt drive roller 104, and each color photosensitive drum 106. 109 and a photosensitive drum driving motor (not shown) for driving the transfer rollers 110 to 113 and a fixing driving motor (not shown) for driving the fixing roller.
[0036]
Further, the image forming apparatus 101 includes a video reading sensor 123.
[0037]
The image reading sensor 123 has the electrostatic transfer belt 125 or the recording paper by irradiating the surface of the electrostatic transfer belt 125 or the surface of the recording paper with light and condensing the reflected light to form an image. It arrange | positions so that the image | video of a specific area may be imaged.
[0038]
Next, the structure of the image reading sensor 123 will be described with reference to FIG.
[0039]
As shown in FIG. 2, the image reading sensor 123 includes an LED 33 serving as a light irradiation unit, a CMOS sensor 34 serving as a reading unit, and lenses 35 and 36 serving as imaging lenses.
[0040]
Light having the LED 33 as a light source is irradiated to the surface of the electrostatic transfer belt 31 or the surface of the recording paper 32 on the electrostatic transfer belt 31 through the lens 35.
[0041]
Reflected light from the electrostatic transfer belt 31 or the recording paper 32 is collected through the lens 36 and imaged on the CMOS sensor 34. Thereby, the surface image of the electrostatic transfer belt 31 or the recording paper 32 is read.
[0042]
In this embodiment, the LED 33 is arranged so that the LED light irradiates the surface of the recording paper 32 obliquely at a predetermined angle as shown in FIG.
[0043]
FIG. 3 is a diagram showing a relationship between the electrostatic transfer belt and the recording material surface image read by the CMOS sensor 34 of the image reading sensor 123 and an example in which the output from the CMOS sensor 34 is digitally processed to 8 × 8 pixels. .
[0044]
The digital processing is performed by converting the analog output from the CMOS sensor 34 into 8-bit pixel data by A / D conversion (not shown) as conversion means.
[0045]
Next, the difference in surface smoothness depending on the type of recording paper will be described.
[0046]
In FIG. 3, reference numeral 40 is an enlarged image of the surface of the recording paper A, which is a so-called rough paper, on which the paper fibers of the surface are relatively clinged, and 41 is the surface of the recording paper B, which is a commonly used so-called plain paper. An enlarged image 42 is an enlarged image of the surface of the recording paper C, which is a so-called glossy paper in which the paper fibers are sufficiently compressed.
[0047]
If the image forming apparatus determines that the fed recording paper is a paper type with a paper fiber on the surface, such as recording paper A shown in FIG. When it is determined that the paper fiber on the surface is smooth, the temperature control of the fixing unit 122 is performed with the fixing temperature set low.
[0048]
Next, a video comparison calculation method, which is a first detection algorithm for detecting the paper surface smoothness and determining the paper type, will be described.
[0049]
In the video comparison calculation, the maximum density pixel Dmax and the minimum density pixel Dmin are derived from the result of reading the video at a plurality of locations on the surface of the recording paper. Addition processing is performed for each of the plurality of read videos.
[0050]
That is, when the paper fiber on the surface is sticking like the recording paper A, many shadows of the fiber are generated. As a result, the difference between the bright part and the dark part is greatly increased, so that Dmax-Dmin is increased, and the Dmax-Dmin addition number of the plurality of images executed a predetermined number of times is increased.
[0051]
On the other hand, on the surface such as the recording paper C, there are few fiber shadows and Dmax-Dmin becomes small, so the Dmax-Dmin addition number of a plurality of images executed a predetermined number of times becomes small.
[0052]
Based on this comparison, the paper type of the recording paper is determined.
[0053]
Although the above-described control circuit can be configured by a hardware circuit, in consideration of control flexibility such as error processing and noise removal processing, video sampling processing, gain and filter calculation processing from the CMOS sensor 34 are performed in real time. Because it needs to be processed, it is desirable to use a digital signal processor.
[0054]
As described above, according to the present embodiment, the state of the paper fiber on the surface of the recording paper is detected by an image, and the temperature control condition of the fixing unit 122 is derived from the result, and the paper fiber on the surface of the recording paper is stuck. If there is, if the fixing temperature is high and the paper fiber on the surface of the recording paper is in a compressed state, the fixing temperature should always be set optimally for the state (roughness) of the recording paper by reducing the fixing temperature. Can do.
[0055]
Next, a recording paper thickness detection method as a second detection algorithm will be described with reference to FIG. 71 is a recording sheet, and 72 to 76 are sampled images arranged in time series.
[0056]
For example, when the leading edge of the recording paper passes through the sensor 70, an image sampled without the leading edge of the recording paper still passing through the sensor 70 is the Sample-1 image 72, and the next sampled image is the Sample-2 image 73. Sample-2 image 73 shows a state in which the leading edge of the recording paper is applied to sensor 70. In this case, the shadow area of the recording paper varies depending on the thickness of the recording paper.
[0057]
In the example shown in the figure, 77 for two pixels is a shadow area proportional to the thickness of the recording paper. Since the recording paper is conveyed, the Sample-3 image 74 and the Sample-4 image 75 and the image move each time the images are sequentially sampled.
[0058]
That is, if the image at the leading edge of the conveyed recording paper is periodically read, the shadow area of the recording paper generated in proportion to the thickness of the recording paper changes. The thickness of the recording paper can be detected by obtaining the shadow length (number of pixels) with respect to the recording paper transport direction.
[0059]
For example, if the reference value is stored in advance in a memory (not shown) such as an EEPROM, the relative recording paper thickness compared with the reference value can be detected.
[0060]
In this way, by changing the fixing temperature condition for recording papers with different thicknesses, the fixing capacity is controlled by increasing the fixing temperature of the fixing unit because the heat capacity of the recording paper with a relatively large thickness is large. A recording sheet having a small target thickness, that is, a small heat capacity, is fixed by lowering the fixing temperature of the fixing means.
[0061]
Next, the detection speed of the recording paper, which is a third detection algorithm, will be described with reference to FIG.
[0062]
For example, if the surface image of the recording material read by the CMOS sensor is 80 images, the images shifted by 1 pixel are 81 to 88 images, respectively. That is, an image that is shifted by one pixel with respect to the transfer material conveyance direction is created using the image read by one sampling as a reference, and is temporarily stored in the memory.
[0063]
Next, the sampled reference image is compared with an image stored in advance, and if they match or if they match with a certain percentage, the number of pixels advanced by that reference image is derived.
[0064]
For example, if the reference image is an image moved by 5 pixels with respect to the previous reference image, if the size of one pixel is 10 μm, it means that it has moved by 50 μm, and the sampling period is 1 kHz. A relative speed of 0.05 mm × 1 KHz = 50 mm / sec is obtained. From this result, the recording paper conveyance drive motor (not shown) is driven and controlled so that the recording paper conveyance speed becomes a constant speed.
[0065]
As described above, in this embodiment, before image formation, a specific area on the surface of the recording paper is irradiated with light by an LED, and the reflected light is imaged on a CMOS sensor as an image, and the image is output. The detection algorithm is selected according to the purpose of detection.
[0066]
As a result, in the result calculated using the first detection algorithm, the type of the recording paper is determined based on the difference in surface smoothness of the recording paper, and in the result calculated using the second detection algorithm, the thickness of the recording paper Is detected, and the conveyance speed of the recording paper is detected from the result calculated using the third detection algorithm. Based on this result, the temperature control condition of the fixing unit or the conveyance speed of the recording paper can be appropriately controlled.
[0067]
In this way, good images can be obtained on various types of recording paper while improving both usability and cost performance.
[0068]
(Example 2)
In Example 1, the surface smoothness of the recording paper, the thickness of the recording paper, or the recording paper conveyance speed was detected. In Example 2, the color misregistration pattern on the electrostatic transfer belt is read and the color misregistration amount is detected.
[0069]
FIG. 6 is a schematic cross-sectional view showing a schematic configuration of an “image forming apparatus” according to the second embodiment.
[0070]
By disposing the image reading sensor 123 at the position shown in FIG. 6, the image on the electrostatic transfer belt 105 and the image on the surface of the recording paper can be taken. Since the schematic configuration of the image forming apparatus and the image on the surface of the recording paper are the same as those described in the first embodiment, the description thereof is cited and the description thereof is omitted here.
[0071]
In FIG. 7, 100 is an image on the electrostatic transfer belt, and 101 is an image captured by the image reading sensor 123.
[0072]
Here, regarding the speed detection of the electrostatic transfer belt 105 which is the fourth detection algorithm, a surface image of the electrostatic transfer belt 105 is taken at a constant cycle, similarly to the detection of the conveyance speed of the recording paper described in the first embodiment. The relative movement amount of this image is obtained to calculate the speed.
[0073]
From this result, the drive motor (not shown) of the electrostatic transfer belt is driven and controlled so that the speed of the electrostatic transfer belt is constant.
[0074]
As a result, for example, the problem that the driving roller of the electrostatic transfer belt is thermally expanded by the heat of the fixing unit and the peripheral speed of the electrostatic transfer belt changes during the continuous printing operation can be solved.
[0075]
Next, a description will be given of color shift detection and color shift control of a developer image, which is a fifth algorithm.
[0076]
This color misregistration detection and control is executed at a specific cycle, for example, every 1000 pages, and calibration is performed mainly to match the latent image writing timing of each color.
[0077]
FIG. 8 is a diagram illustrating the developer image transferred onto the electrostatic transfer belt 105.
[0078]
An electrostatic transfer belt 200, a black toner image 201, a cyan toner image 202, a magenta toner image 203, and a yellow toner image 204 are drawn at predetermined intervals. The toner image is read from the image by the image reading sensor 123.
[0079]
Reference numeral 300 in FIG. 9 denotes a pattern image obtained by reading the toner image.
[0080]
Reference numeral 301 denotes a leading end of the pattern, and 302 denotes an image pattern portion. In this way, the leading edge of the pattern is captured every time an image pattern of each color arrives.
[0081]
The amount of color misregistration of each color with respect to the transport direction is determined by whether or not t1, t2, and t3 are specified values with reference to the black pattern 201. Therefore, what is necessary is just to obtain | require the time of this t1-t2.
[0082]
Next, the color misregistration detection control flow will be described with reference to FIG.
[0083]
First, each register and counter are reset at s1. Next, at s2, the image is read by the reading sensor. This reading operation is performed at regular intervals, for example, 1 ms intervals. This sampling time is determined in consideration of the speed with respect to the electrostatic transfer belt so that the leading edge of the pattern is surely captured within the area of the reading sensor. Next, the number of times of image reading is counted in s3, and the leading edge of the pattern is detected in s4. This recognizes the leading edge of the pattern when an image as shown in FIG. 9 is captured. For example, in the case of a reading sensor having 8 × 8 pixels, when an area in a specific range (the lower pixel in the case of FIG. 9) is all black, this is recognized as a pattern image, and the edge is recognized as the leading edge of the pattern. Realized by grasping as If the leading edge of the pattern is not detected in s4, the timer is monitored in s5, and if it is timed out, an abnormal state is indicated that the leading edge of the pattern has not been read even if a predetermined time has passed in s6, and a color misregistration detection control error occurs. Set the flag and exit.
[0084]
On the other hand, when the leading edge of the pattern is detected, the pixel is corrected in s7. This is an operation for deriving which pixel position in the reading sensor the image captured as the leading edge of the pattern is located.
[0085]
Next, the value is set in the register in s8, the pattern count is incremented in s9, and it is determined whether or not it is a black pattern in s10. If so, the sample count value and the pixel correction value are stored in s11. .
[0086]
If the pattern is not “1” in s10, that is, if it is not a black pattern, it is determined in s12 whether the pattern is “2”, that is, whether it is a cyan pattern. If so, the sample count is performed in s13. Then, the pixel correction value is recorded, and a time t1 from the black pattern leading edge to the cyan pattern leading edge is calculated in s14.
[0087]
The details of this calculation method will be described as an example. First, when measuring the time from the front end of the black pattern to the front end of the cyan pattern, the sampling count and the pixel correction value stored when the front end of the black pattern is captured are used as a reference. For example, assume that the sampling count is #A, and the leading edge of the pattern is a pixel from the leading edge of the reading sensor. The next cyan pattern tip captured is sampling count #B, and the pattern tip is b pixels from the tip of the reading sensor. If the sampling period is 1 ms and the pixel movement time is 1/8 ms, the cyan pattern starts from the tip of the black pattern. The tip time is
t1 = (B−A−1) ms + (8−a + b) * 1/8 ms
[0088]
Similarly, t2 is measured from s15 to s17, and t3 is measured from s18 to s20.
[0089]
On the other hand, if the pattern “4”, that is, the yellow pattern is not detected, the timer is monitored in s21, and if it is timed out, the error flag is set in s22 and the process ends.
[0090]
If not timed out, image sampling is performed again.
[0091]
As described above, the measured values of t1, t2, and t3 are compared with the reference values prepared in advance to obtain the amount of color misregistration with the black color reference, and based on these values, latent image forming timings for cyan, magenta, and yellow are obtained. To decide. Thereby, the shift amount of each color can be reduced.
[0092]
As described above, in this embodiment, the image reading sensor is provided at the position for reading the surface of the electrostatic transfer belt, and an arithmetic algorithm corresponding to the detection application is selected from the output of the image.
[0093]
As a result, in the result calculated using the fourth detection algorithm, the speed of the electrostatic transfer belt is detected, and in the result calculated using the fifth detection algorithm, the color shift transferred onto the electrostatic transfer belt is detected. The color misregistration amount of the pattern is detected, and the electrostatic transfer belt speed control and latent image writing timing are controlled from the result.
[0094]
In this way, it is possible to obtain a good image without color misregistration while improving both usability and cost performance.
Example 3
FIG. 11 is a cross-sectional view illustrating a configuration of an “image forming apparatus using an intermediate transfer member” according to the third embodiment.
[0095]
In the figure, 301 is an image forming apparatus, 302 is an intermediate transfer member for transferring a toner image formed on the surface of the photosensitive drum 303, 304 is a developing sleeve for developing the toner included in the developing unit 306 on the photosensitive drum 303, and 305 A coating roller for uniformly feeding toner to the developing sleeve, 307 is a rotary unit, 308 is a secondary transfer unit, 309 is a transfer material, 310 is a fixing unit, 311 is a scanner unit, and 312 is an image reading sensor.
[0096]
As described above, in the image forming apparatus including the intermediate transfer member, the surface image of the intermediate transfer member is captured using the image reading sensor described in the first and second embodiments. The speed of the intermediate transfer member 312 can be detected by the third detection algorithm, and the speed of the intermediate transfer member 312 can be controlled to be constant. In particular, the peripheral speed of the intermediate transfer member 312 depends on the temperature rise in the image apparatus or the secular change. It is possible to prevent deterioration of color misregistration due to change.
[0097]
Similarly to the second embodiment, the color misregistration amount is detected by the color misregistration pattern transferred onto the intermediate transfer member, the latent image writing timing is controlled, and the color misregistration can be eliminated.
[0098]
(Deformation)
In the image forming apparatus using the intermediate transfer member, as in the first embodiment, the image reading sensor is arranged at a position where the image on the recording paper can be read, and an image of a specific area on the recording paper is picked up. Based on the result calculated using the detection algorithm, the type of the recording paper is determined based on the difference in surface smoothness of the recording paper. The thickness of the recording paper is detected based on the result calculated using the second detection algorithm. The conveyance speed of the recording paper is detected from the result calculated using the three detection algorithms. Based on the determination and detection result, the temperature control condition of the fixing unit or the conveyance speed of the recording paper can be appropriately controlled.
[0099]
In the first and second embodiments, the type of the recording paper is determined based on the difference in surface smoothness of the recording paper based on the result calculated using the first detection algorithm, and the second detection algorithm is used. The thickness of the recording paper was detected from the calculated result, and the temperature condition of the fixing unit was controlled.
[0100]
However, if the recording paper is smooth or rough, the transferability of the developer deteriorates. Further, when the recording paper is thick, the transferability of the developer is deteriorated.
[0101]
Such a case can be improved by raising the developing bias of the developing means or raising the transfer bias of the transferring means.
[0102]
【The invention's effect】
  As described above, according to the present invention, an image forming apparatus capable of obtaining a good image while improving both usability and cost performance by using one video reading sensor for multiple purposes.PlaceCan be provided.
[0103]
  For more information, see1According to the described invention, it is possible to obtain a good image by performing processing under optimum fixing processing conditions, development processing conditions, and transfer processing conditions for various types of recording materials while improving usability and cost performance. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of Example 1
FIG. 2 is a diagram showing the configuration of a video reading sensor
FIG. 3 is an explanatory diagram of state detection of the recording paper surface.
FIG. 4 is an explanatory diagram of recording sheet thickness detection.
FIG. 5 is an explanatory diagram of recording sheet conveyance speed detection.
6 is a cross-sectional view showing a configuration of Example 2. FIG.
FIG. 7 is a diagram showing a surface image of an electrostatic transfer belt
FIG. 8 is a view showing a developer image transferred on the electrostatic transfer belt.
FIG. 9 shows a pattern tip image.
FIG. 10 is a flowchart showing a color misregistration detection control flow.
FIG. 11 is a cross-sectional view showing the configuration of Example 3
[Explanation of sign]
105 Electrostatic transfer belt
106 to 109 Photosensitive drum
114 to 117 developing roller
122 Fixing unit
123 Image reading sensor

Claims (2)

An image carrier, a developing unit that develops the latent image by applying a developer to the latent image formed on the image carrier, and a transfer that transfers the developer image developed by the developing unit to a recording material. An image forming apparatus comprising: a fixing unit that fixes the developer image on the recording material by heating and pressurizing the recording material on which the developer image has been transferred by the transfer unit;
A light irradiation means for irradiating the surface of the recording material with light;
Reading means for reading the light emitted from the light irradiation means and reflected by the surface of the recording material as an image;
A calculation means for calculating a video read by the reading means using a plurality of algorithms,
The plurality of algorithms include a first algorithm for calculating data indicating the surface smoothness of the recording material using the image of the surface of the recording material read by the reading unit, and a leading end of the recording material read by the reading unit. A second algorithm for calculating data indicating the thickness of the recording material using the image of the recording portion, and data indicating the conveyance speed of the recording material using a plurality of images of the surface of the recording material read by the reading means A third algorithm,
The calculating means is based on data indicating the surface smoothness of the recording material calculated using the first algorithm and data indicating the thickness of the recording material calculated using the second algorithm. And controlling the recording material conveyance speed to be constant based on data indicating the recording material conveyance speed calculated by using the third algorithm. The image forming apparatus according to claim 1, wherein the light irradiation unit is arranged to irradiate light obliquely at a predetermined angle with respect to a surface to be read.

Images