JP4642632B2 - Image forming apparatus and image forming method - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method, and more particularly, to image formation such as an electrophotographic apparatus and electrostatic recording apparatus including an image heating apparatus that heat-fixes an unfixed image formed and supported on a recording material. The present invention relates to an apparatus and an image forming method thereof.

  Image forming apparatuses such as copying machines and laser printers include a latent image carrier that carries a latent image, and a developing device that visualizes the latent image as a developer image by applying a developer to the latent image carrier. . The image forming apparatus further includes a transfer unit that transfers the developer image by the developing device to a recording material conveyed in a predetermined direction. The image forming apparatus further fixes the developer image to the recording material by heating and pressurizing the recording material, which has received the transfer of the developer image by the transfer unit, under predetermined fixing processing conditions. Equipment.

  In an image forming apparatus, for example, the size and type (hereinafter also referred to as a paper type) of a recording sheet, which is a recording material, is set by a user on an operation panel or the like provided in the main body of the image forming apparatus, and fixing is performed according to the setting. Control is performed to set processing conditions. The fixing processing conditions that are set are, for example, the fixing temperature and the conveyance speed of the recording material that passes through the fixing device.

  Therefore, an image forming apparatus as referred to in Patent Document 1 has been proposed. The image forming apparatus includes a fixing device that thermally fixes an unfixed image by passing the recording material on which an unfixed image has been formed in contact with a heating rotator heated by an electric heating unit, Rotating body temperature detecting means for detecting the temperature of the heating rotating body in the fixing device is provided. The image forming apparatus further includes a control unit that performs control to stop at least the heating rotator when the temperature detected by the rotator temperature detecting unit reaches a fixing lower limit temperature. The image forming apparatus is further provided with a temperature determining unit that determines and changes the lower limit fixing temperature used by the control unit based on the actual condition of the image forming environment.

  Furthermore, an image forming apparatus as referred to in Patent Document 2 has been proposed. The image forming apparatus includes a light irradiating unit that irradiates light onto the surface of the recording material before fixing, and a reading unit that reads and outputs an image of a light irradiation area of the surface of the recording material by the light irradiating unit. The image forming apparatus further includes a fixing condition setting unit that controls to set a fixing process condition of the fixing device in accordance with an output value from the reading unit. In this image forming apparatus, whether or not the recording material is a transparent original paper such as an OHP sheet is automatically detected, and if light is transmitted through the recording material, it is determined as a transparent original paper, and the light is not transmitted through the recording material. Are determined to be reflective original paper such as paper. In this image forming apparatus, control is further performed to determine the thickness of the recording material and the unevenness of the surface, and to set the fixing temperature or the recording material conveyance speed according to the determination result.

  An image forming apparatus as referred to in Patent Document 3 has been proposed. The image forming apparatus detects the amount of water contained in the recording material, sets fixing processing conditions such as a fixing temperature and a fixing speed based on the detection result, and performs an appropriate fixing process according to the amount of water in the recording medium. To obtain a stable image.

JP 2000-321923 A JP 2002-182518 A Japanese Unexamined Patent Publication No. 2000-19886

  Conventionally, since the user has to set the paper type in the image forming apparatus or the host computer, the operability of the image forming apparatus is poor. In particular, there is a problem that the burden on the user is large and the usability is poor.

  As in Patent Literatures 1 to 3, the fixing condition is automatically set by detecting the surface property and thickness of the recording material, or the fixing condition is automatically detected by detecting the temperature of the recording material or the moisture content of the recording material. Thus, an invention has been made to reduce the burden on the user and improve productivity and image quality. However, those disclosed in each of Patent Documents 1, 2, and 3 automatically set the fixing conditions in consideration of the characteristics of the recording material individually. This automatic setting does not take into account all of the characteristics such as the type of recording material, the temperature of the recording material, and the amount of moisture in the recording material. In some cases, the wraps around the heated rotating body.

  An object of the present invention is to avoid the fixing condition determination mistakes that have been seen in the past, to improve usability, and to obtain a good fixed image by performing fixing processing on various types of recording materials under optimal fixing processing conditions. A forming apparatus and an image forming method thereof are provided.

In order to achieve the above object, an image forming apparatus according to the present invention includes a transfer unit that transfers an image onto a recording material, a fixing unit that fixes the image transferred onto the recording material, and information relating to the surface property of the recording material. and a recording material information detecting means for detecting information relating to the thickness, the environment detecting means for detecting environmental information, on the basis of said environment information and information relating to the thickness information related to the surface property, the transfer And a processing means for setting a leading edge margin amount when the image is transferred to the recording material by the means , a heating temperature when the image is fixed to the recording material by the fixing means , and a conveyance speed of the recording material. and, said transfer means to transfer the image on the recording material on the basis of the leading end margin amount set by said processing means, and said fixing means, the heating temperature and the conveying set by said processing means speed Based characterized by fixing the image transferred to the recording material.

The image forming method of the present invention, a transfer unit that transfers the image on a recording material, a fixing unit and an image forming method for an image forming apparatus having a for fixing the image transferred to the recording medium, the recording medium A recording material information detecting step for detecting information relating to the surface property of the recording medium and information relating to the thickness of the recording material, an environmental information detecting step for detecting environmental information of the image forming apparatus, and a surface property of the recording material Based on the information, the information related to the thickness of the recording material, and the environmental information, the leading edge margin amount when the image is transferred to the recording material by the transfer unit, and the image is fixed on the recording material by the fixing unit a setting step of setting the conveying speed of the heating temperature and the recording material at the time of a transfer step of transferring the image on the recording material on the basis of the leading end margin amount set in said setting step, said transcription stearate The image transferred to the recording material in-flop, and having a fixing step of fixing the recording medium on the basis of the heating temperature and the conveying speed set by the setting step.

  The apparatus and method according to the present invention employs a configuration in which the process conditions of the fixing process of the fixing unit are changed based on the detection result. As a result, process condition determination errors that may have occurred can be avoided, and usability can be improved, and a fixed image can be obtained with various types of recording materials under the optimal fixing process conditions to obtain a good fixed image. Can do. In addition, the recording material can be prevented from being wound around the heating rotator by changing the leading edge margin.

(Image forming apparatus configuration)
The present invention can be implemented by an image forming apparatus having a general configuration as shown in FIG. In FIG. 1, an image forming apparatus 101 includes a paper cassette 102, a paper feed roller 103, a registration roller 126, a transfer belt driving roller 104, a transfer belt 105, and yellow, magenta, cyan, and black photosensitive drums 106 to 109. The image forming apparatus 101 further includes transfer rollers 110 to 113 for each color, yellow, magenta, cyan, and black cartridges 114 to 117, yellow, magenta, cyan, and black optical units 118 to 121, and a heat fixing device. A fixing device 122 is provided.

  In the image forming apparatus 101, the recording material is fed by the paper feed roller 103, the skew is corrected by the registration roller 126, and the timing is adjusted. On this recording material, yellow, magenta, cyan, and black images are generally transferred in an overlapping manner using an electrophotographic process. The transferred toner image is thermally fixed by controlling the temperature by the fixing nip portion of the fixing device 122 formed by pressing the fixing roller and the pressure roller 127. The optical units 118 to 121 for each color are configured to form a latent image by exposing and scanning the surfaces of the photosensitive drums 106 to 109 with a laser beam, and these series of image forming operations are performed on the recording material to be conveyed. Synchronization is performed so that the image is transferred from a predetermined position.

  The image forming apparatus to which the present invention is applied is not limited to the configuration shown in FIG. The present invention can also be applied to an image forming apparatus having a configuration in which an image formed on a photosensitive drum is transferred onto an intermediate transfer member, and then transferred onto a recording material in a lump. In addition, an image forming apparatus that employs a toner jet method that forms an image by discharging toner onto a recording material (or an intermediate transfer member) as a method for forming an image on a recording material, also includes an embodiment described below. It is possible to apply.

  Further, the image forming apparatus 101 includes a sheet feeding motor that feeds and conveys a recording material, which is a recording material, and the fed recording material is desired on the surface of the recording material while being conveyed to a transfer belt and a fixing roller. Form an image of

  The image reading sensor 123 is arranged before the recording material is transported to the transfer belt, irradiates the surface of the recording material that has been transported, collects the reflected light and forms an image, and forms the surface of the recording material. The image of the specific area is read out.

  A control CPU 210 that controls the image forming apparatus 101 described below with reference to FIG. 2 causes the fixing device 122 to fuse and fix the toner image on the recording material by applying a desired amount of heat to the recording material.

  Next, the operation of the control CPU 210 of an embodiment of the image forming apparatus which is the present invention apparatus will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration of each unit controlled by the control CPU 210. In FIG. 2, a control CPU 210 is connected to a CMOS sensor 211 and polygon mirrors, motors, and lasers 212 to 215 included in each color optical unit, scans the laser on the surface of the photosensitive drum, and draws a desired latent image. For controlling the optical unit. The control CPU 210 includes a paper feed motor 216 for transporting the recording material, a paper feed solenoid 217 used to start driving the paper feed roller for feeding the recording material, and whether or not the recording material is set at a predetermined position. The paper presence / absence sensor 218 is also controlled. The control CPU 210 also controls a high voltage power source 219 that controls primary charging, development, primary transfer, and secondary transfer bias necessary for the electrophotographic process, and a drum driving motor 220 that drives the photosensitive drum and the transfer roller. The control CPU 210 also controls the belt driving motor 221 for driving the transfer belt and the rollers of the fixing device, the fixing device, and the low voltage power supply unit 112. Further, the temperature is monitored by the thermistor 225 by the control CPU 210, and the heat source 226 such as a halogen heater, induction heating, resistance heating element, etc. is controlled to keep the fixing temperature constant.

  The control CPU 210 is connected to the memory 224 via a bus or the like (not shown). The memory 224 stores programs and data for executing the above control and all or part of the processing performed by the control CPU 210 in each embodiment described in this specification. That is, the control CPU 210 executes the operation of each embodiment of the present invention using the program and data stored in the memory 224.

  The ASIC 223 performs motor speed control inside the CMOS sensor 211 and the optical units 212 to 215 and speed control of the paper feed motor based on an instruction from the control CPU 210. The speed control of the motor is performed by detecting a tack signal from a motor (not shown) and outputting an acceleration or deceleration signal to the motor so that the interval between the tack signals becomes a predetermined time. For this reason, it is more advantageous that the control circuit is composed of a hardware circuit of the ASIC 223 so that the control load on the control CPU 210 can be reduced.

  When receiving a command print command from a host computer (not shown), the control CPU 210 determines the presence / absence of a recording material by the paper presence / absence sensor 218. When there is paper, the control CPU 210 controls the paper feed motor 216, the drum drive motor 220, and the belt drive motor 221, and drives the paper feed solenoid 217 to convey the recording material to a predetermined position.

  When the recording material is conveyed to the position of the CMOS sensor 211, the control CPU 210 instructs the ASIC 223 to capture an image using the CMOS sensor 211, and the CMOS sensor 211 captures a surface image of the recording material. At this time, the ASIC 223 activates Sl_select, and then outputs SYSCLK of a predetermined pulse at a predetermined timing, and captures imaging data output from the CMOS sensor 211 via Sl_out.

  The gain of the CMOS sensor 211 is set by setting a value determined in advance by the control CPU 210 in a register in the ASIC 223 so that the ASIC 223 activates Sl_select and then outputting SYSCLK of a predetermined pulse at a predetermined timing. This is performed for the CMOS sensor 211 via Sl_in.

  As shown in FIG. 7, the ASIC 223 includes a circuit 702 for realizing the method of the present invention described below, and the calculation result of the calculation described later for determining the attribute of the recording material is stored in a register in the control circuit 702. A and register B are stored. Then, the control CPU 210 reads the calculation result for determining the attribute of the recording material stored in the register A and the register B in the control circuit 702, determines the type of the fed recording material, and according to the result To change the image forming conditions.

  Examples of the control of various image forming conditions executed by the control CPU 210 include the following.

  For example, when the type of the recording material is glossy paper having a glossiness higher than that of plain paper, the control CPU 210 increases the glossiness of the image on the recording material by increasing the amount of toner attached to the surface of the recording material. I do. In order to increase the amount of toner, the control CPU 210 controls to increase the developing bias higher than that of plain paper and increase the potential difference with respect to the surface potential of the photosensitive drum. This is because it is desired to increase the glossiness of the image on the recording material when printing using glossy paper. The developing bias (voltage) is a voltage applied to the developing roller from the high voltage power source 219 based on an instruction from the control CPU 210 as shown in FIG.

  Further, the control CPU 210 controls to change the fixing temperature of the fixing device 122 (a target temperature to be maintained by a heater (not shown) in the fixing device 122) according to the type of the recording material fed. In the case of thick paper that is thicker than plain paper, the thick paper has a heat capacity larger than that of plain paper, so that there is a problem that fixing properties are deteriorated even if a toner image is fixed on the thick paper at the same fixing temperature as that of plain paper. Therefore, when the control CPU 210 determines that the recording material is thick paper, the control CPU 210 controls the toner to fix the toner to the thick paper at a fixing temperature higher than the fixing temperature of the plain paper.

  Further, the control CPU 210 determines the type of the fed recording material and performs control so as to change the conveyance speed of the recording material according to the result. The control of the conveyance speed is realized by resetting the speed control register value of the ASIC 223 that actually controls the speed by the control CPU 210. Specifically, when the type of recording material is thick paper that is thicker than plain paper, the thick paper has a larger heat capacity than plain paper, so the toner image can be fixed on the thick paper at the same transport speed as plain paper. Has the problem of getting worse. Therefore, when the control CPU 210 determines that the type of the recording material is thick paper, the conveyance speed when the recording material is fed at the conveyance speed so that the amount of heat supplied to the thick paper per unit time increases. Set slower than the speed.

  A method of changing the fixing temperature condition for recording materials having different basis weights is also conceivable. For example, a relatively thick recording material has a large heat capacity, so the fixing temperature is controlled to be higher. On the other hand, a recording material with a relatively small thickness, that is, a smaller heat capacity (in the case of the same material), lowers the fixing temperature. Then, a fixing method can be considered. Alternatively, the recording material conveyance speed can be changed and controlled according to the basis weight of the recording material.

  Further, in the case of an OHP sheet or glossy paper, it is possible to improve the image quality by discriminating these and improving the fixability of the toner adhering to the surface of the recording material to enhance the gloss.

  As described above, in the present embodiment, the first calculation and the second calculation are performed from the surface image of the recording material imaged by the CMOS area sensor 211 by the ASIC hard circuit. From this calculation result, the control CPU can control to change the developing bias condition of the high voltage power supply, the fixing temperature of the fixing device, or the conveyance speed of the recording material.

  Next, an embodiment of the present invention will be described. FIG. 3 is a schematic diagram showing a schematic configuration for detecting the surface smoothness, the reflected light amount, and the transmitted light amount of the recording material.

  As shown in FIG. 3, the image reading sensor 123 includes a reflection LED 301, a transmission LED 302 for detecting a transmitted light amount installed on the opposite side of the recording material 304, a CMOS area sensor 211, and an imaging lens 303. . Here, the CMOS area sensor 211 can be replaced with a CCD sensor.

  Light using the reflective LED 301 as a light source is irradiated toward the surface of the recording material 304. In this embodiment, the light source is an LED, but a xenon tube, a halogen lamp, or the like can also be used. The reflected light from the recording material 304 is condensed through the lens 303 and forms an image on the CMOS area sensor 211. As a result, an image on the surface of the recording material 304 can be read.

  In the present embodiment, the LED 301 is arranged so that the LED light irradiates the recording material 304 with light at an angle as shown in FIG.

(Determination of recording material type)
FIG. 4 is a diagram showing a comparison between an analog image on the surface of the recording material 304 read by the CMOS area sensor 211 of the video reading sensor 123 and a digital image obtained by digitally processing the output from the CMOS area sensor 211 into 8 × 8 pixels. is there. Here, the digital processing is performed by converting the analog output from the CMOS area sensor 211 into 8-bit pixel data by A / D conversion.

  In FIG. 4, the recording material A401 is a so-called rough paper in which the paper fibers on the surface are relatively sandwiched, the recording material B402 is a so-called plain paper that is generally used, and the recording material C403 is sufficiently compressed in the paper fibers. Glossy paper, and each is a magnified image of the surface. These images 401 to 403 read into the CMOS sensor 211 are digitally processed into images 404 to 406 shown in FIG. Thus, the image on the surface varies depending on the type of recording material. This is a phenomenon that occurs mainly because the fiber state on the paper surface is different.

  Apart from this, the amount of reflected light of the recording material is generally calculated from the total or average value of the light input to each pixel. However, depending on the embodiment, only the result of one light receiving pixel can be used.

  As described above, the surface state of the paper fiber of the recording material can be identified by an image obtained by digitally processing the image obtained by reading the surface of the recording material by the CMOS area sensor 211. Discrimination becomes possible.

  The recording material surface can be identified as follows. First, a part of the surface of the recording material is read as an image composed of 8 × 8 pixels, and the pixel density Dmax and the minimum density of the pixel having the maximum density for one line in the direction orthogonal to the recording material conveyance direction in the image are read. The density Dmin is detected. Dmax and Dmin are detected for each line, and Dmax−Dmin is averaged. The material (smoothness) that is an attribute of the recording material can be determined based on the value of Dmax−Dmin obtained by the averaging process.

  That is, when the paper fiber on the surface is rough like the recording material A, many shadows of the fiber are generated. As a result, the difference between the bright part and the dark part is large, and Dmax−Dmin becomes large. On the other hand, the image of the surface of a recording material having a sufficiently smooth fiber and a high smoothness like the recording material C has less fiber shadow and Dmax−Dmin becomes small. By this comparison, the material of the recording material is determined and used as a part of information for determining the type.

For example, when analog output from the CMOS area sensor 211 is A / D converted into 8-bit, 256-gradation digital data, the following determination can be made.
(1) Dmax−Dmin ≦ 10 ....... determined as glossy film (2) 10 <Dmax−Dmin ≦ 20 ·· determined as glossy paper (smooth paper) (3) 20 <Dmax−Dmin ≦ 30 · normal Judged as paper, etc. (plain paper, thick paper 1, thick paper 2 or thin paper) (4) 30 <Dmax−Dmin.

  In FIG. 4, an image 407 is a surface enlarged image in a light irradiation region of light transmitted through the recording material by the transmission LED 302 of the recording material D which is thin paper. The image 408 is an enlarged image of the surface of the light irradiation area by the transmission LED 302 of the recording material E that is commonly used so-called plain paper. An image 409 is an enlarged image of the surface of the light irradiation area by the transmission LED 302 of the recording material F that is a cardboard. These images 407 to 409 read into the CMOS area sensor 211 are digitally processed into the images 410 to 412 in FIG.

  In this way, the amount of transmitted light and its image vary depending on the type of recording material. This is a phenomenon that occurs mainly because the fiber state on the paper surface and the compressed state of the paper fiber are different.

  Since the control CPU 210 needs to process the video sampling processing, gain and filter calculation processing from the CMOS area sensor 211 in real time, it is desirable to use a digital signal processor.

  Next, a method for measuring the transmittance of the recording material 304 will be described. Light having the transmissive LED 302 as a light source is emitted toward the recording material 304 from the opposite side of the image reading sensor 123 so as to enter the reading area of the image reading sensor 123 on the recording material.

  FIG. 5 is a diagram showing the surface of the recording material 304 read by the CMOS area sensor 211 of the image reading sensor 123 using the transmissive LED 302 and digitally processing the output from the CMOS area sensor 211 into 8 × 8 pixels. It is. The light transmitted through the recording material 304 is collected through the lens 303 and enters the CMOS area sensor 211. At this time, normally, the total amount or the average value of the light amounts input to each pixel in the entire sensor area or in a predetermined range is used as the transmitted light amount, but only the result of one light receiving pixel can be used.

  FIG. 6 is a diagram showing the relationship between the basis weight of the recording material and the transmitted light. For example, a recording material with a large basis weight such as thick paper has a small amount of transmitted light, whereas a recording material with a low basis weight such as thin paper has a large amount of transmitted light. Based on this characteristic, the material thickness, which is one of the attributes of the recording material, is determined based on the amount of transmitted light, which is one piece of information for determining the type of the recording material.

There are the following types of recording materials assumed in the present embodiment, and the type is determined according to the surface state and the material thickness as will be described below. The basis weight G [g / m ² ] described below refers to the weight per unit volume of the recording material.
(1) thin paper (basis ^{weight: G ≦ 64 [g / m} 2])
(2) Plain paper (basis weight: 64 <G ≦ 105 [g / m ² ])
(3) Cardboard 1 (basis weight: 105 <G ≦ 135 [g / m ² ])
(4) Cardboard 2 (basis weight: 135 <G [g / m ² ])
(5) Glossy paper (6) Glossy film (7) Transparent original (OHP sheet)
Since the amount of light reflected from the recording material is transparent (7) is transparent and has high light transmittance, there are two sets of (1) to (6) reflective originals and (7) transparent originals.

  Three sets (1) to (4), (5), and (6) are determined from the contrast ratio of the image obtained from the reflected light of the recording material. Here, in this embodiment, when detecting the light / dark ratio for this determination, normalization based on the amount of reflected light is performed. That is, if there is a difference in the total light amount of the two-dimensional image, the value of Dmax−Dmin also changes, so normalization is performed so that the average value of the light amount of the entire two-dimensional image matches.

  The basis weights of (1) to (4) are different depending on the amount of transmitted light, and the received light amount of transmitted light when a constant amount of light is irradiated from the back of the paper is (1)> (2 )> (3)> (4), so that there are four types (1), (2), (3), and (4). Here, in the present embodiment, the determination is performed using the average value of the transmitted light amount of all the pixels including 8 × 8 pixels.

  By combining the above determinations, various recording materials (1) to (7) can be accurately determined.

(Implementation of recording material discrimination function)
A control circuit of the CMOS area sensor 211 for performing the above operation will be described with reference to FIG. FIG. 7 is a block diagram showing a control circuit of the CMOS area sensor 211. In FIG. 7, the control CPU 210 as a determination unit includes a control circuit 702, a CMOS area sensor 211, an interface control circuit 704, an arithmetic circuit 705, a register A 706, a register B 707, and a control register 708.

  Next, the operation will be described. When the control CPU 210 gives an operation instruction for the CMOS area sensor 211 to the control register 708, the recording of the recording material surface image is started by the CMOS area sensor 211. That is, charge accumulation in the CMOS area sensor 211 is started. When the CMOS area sensor 211 is selected by Sl_select from the interface circuit 704 and SYSCLK is generated at a predetermined timing, the captured digital image data is transmitted from the CMOS area sensor 211 via the Sl_out signal.

  The imaging data received via the interface circuit 704 is calculated by the control circuit 702, and the calculation result is stored in the register A 706 and the register B 707. The control CPU 210 determines the attribute of the recording material from the register values of the register A 706 and the register B 707.

  Note that the value stored in the register A 706 is a value obtained by averaging Dmax-Dmin for 8 lines for a part of the surface of the recording material acquired as an image by the CMOS area sensor 211. LED 301 irradiates the surface of the recording material. The value stored in the register B707 is a value obtained by averaging the amount of light of each pixel of 8 × 8 pixels with respect to a part of the surface of the recording material acquired as an image by the CMOS area sensor 211, and this image is acquired. At this time, the transmissive LED 302 irradiates the back surface of the recording material.

  Next, a sensor circuit block diagram will be described with reference to FIG. FIG. 8 is a circuit block diagram of the CMOS area sensor 211. In FIG. 8, a CMOS area sensor 211 includes a CMOS sensor portion 801, for example, sensors of 8 × 8 pixels are arranged in an area. The CMOS area sensor 211 further includes vertical shift registers 802 and 803, an output buffer 804, a horizontal shift register 805, a system clock 806, and a timing generator 807.

  Next, the operation will be described. When the Sl_select signal 813 is activated, the CMOS sensor unit 801 starts accumulating charges based on the received light. Next, when the system clock 806 is applied, the vertical shift registers 802 and 803 sequentially select the pixel columns to be read out by the timing generator 807 and the data is sequentially stored in the output buffer 804.

  Data stored in the output buffer 804 is transferred to the A / D converter 808 by the horizontal shift register 805. The pixel data digitally converted by the A / D converter 808 is controlled at a predetermined timing by the output interface circuit 809, and is output to the Sl_out signal 810 while the Sl_select signal 813 is active.

  On the other hand, the control circuit 811 can be controlled to change the A / D conversion gain from the Sl_in signal 812. For example, if the contrast of the captured image cannot be obtained, the control CPU can change the gain and always capture with the best contrast.

  In this way, by using two irradiation means of the reflective LED 301 and the transmissive LED 302, it is possible to detect the surface state, reflectance and transmittance of various recording materials, and to determine the type of the recording material. Become.

(Recording material temperature and moisture content detection)
In the apparatus according to the present embodiment, as shown in FIG. 1, an environment detection unit 124 is provided in a paper feeding unit that feeds a recording material. The environment detection unit 124 includes a temperature sensor and a humidity sensor, and detects the temperature and humidity in the image forming apparatus. In the present embodiment, control is performed so that the control CPU 210 sets the fixing condition according to the environment from the temperature and humidity obtained by the environment detection unit 124.

  For example, even under the same temperature condition, if the humidity is high and the moisture content of the recording material is large, the heat of vaporization increases during fixing. Therefore, even if the same amount of heat is applied to the recording material, more heat is lost as vaporization heat. Therefore, under the same temperature condition, the higher the humidity and the higher the moisture content of the recording material, the lower the temperature of the recording material and the poor fixability of the unfixed image. Further, if the moisture content of the recording material is large, the recording material becomes weak and easily wound around the fixing roller.

  When the moisture content of the recording material is the same, the lower the temperature, the worse the fixing property. Also, the recording material becomes stiff and less likely to wind around the fixing roller.

  Accordingly, the following embodiments are configured to obtain good fixability regardless of the environment by detecting the temperature and humidity and changing the fixing conditions according to the environment.

[First Embodiment]
(First embodiment)
A control flow by the control CPU 210 that executes fixing process condition control provided in the image forming apparatus 101 according to the present embodiment will be described.

  First, a method for determining whether a document is a transparent document or a reflective document and a method for determining the thickness of a recording material will be described with reference to FIG. In this example, the amount of light transmitted through the recording material is checked to determine whether it is a transparent original (OHP sheet) or a reflective original. In the case of a reflective original, the thickness of the recording material is checked from the compressed state of paper fibers. First, the transmissive LED 302 is turned on (S901), the CMOS area sensor 211 reads a surface image in the light irradiation region of the transmissive LED 302 (S902), and calculates the average value of all pixels. That is, since the transparent document has a larger average amount of transmitted light than the reflective document, it can be determined whether the document is a transparent document or a reflective document. Next, when the compression of the fiber is small as in the recording material D in the reflection original, the average value of the transmitted light amount is high, and when the compression of the fiber is high as in the recording material F, the average value of the transmitted light amount is low. Therefore, the attribute can be determined by comparing each average value.

After the transmissive LED 302 is turned off (S903), the average value is compared with a reference value previously stored in a memory such as an EEPROM (S904). Based on the result, the transmissive original (OHP sheet), thin paper, plain paper, thick paper is compared. 1 and cardboard 2 are determined. Here, based on the reference values R1 to R4 (R1>R2>R3> R4), the determination is made as follows.
(A) R1 <average value of all pixels... Transparent document (OHP sheet) and determination (B) R2 <average value of all pixels ≦ R1... Thin paper (C) R3 <all pixels Average value ≦ R2... Normal paper (D) R4 <Average value of all pixels ≦ R3... Judged as thick paper 1 (E) Average value of all pixels ≦ R4.

  Here, it is determined whether the document is a transparent document or a reflective document other than (A) and (A) (S905). If (A), fixing condition setting 1 (S906) is set. If it is other than (A), the paper thickness of any one of (B) to (E) is determined (S907). This result is set as fixing condition setting 2 (S908).

  The control CPU 210 preferably uses a digital signal processor because it needs to process the video sampling processing, gain and filter calculation processing from the CMOS area sensor 211 in real time.

  Next, the surface property of the recording material is determined using FIG. First, the reflective LED 301 is turned on (S1001), and the CMOS area sensor 211 reads an image of the recording material (S1002). Video reading is performed a plurality of times, and video is read at a plurality of locations on the recording material.

  After turning off the LED 301 for reflection (S1003), as fixing condition control, a gain calculation for gain adjustment and a constant for filter calculation are adjusted (S1004). This gain calculation and filter calculation are processed by the control CPU 210 in a programmable manner. For example, the gain calculation is performed by adjusting the gain of the analog output from the CMOS area sensor 211. In other words, if the amount of reflected light reflected from the surface of the recording material is too large, or conversely too small, the image on the surface of the recording material cannot be read effectively, and if the change in the image cannot be derived, adjust the gain. And adjust the light intensity to an appropriate value. Further, the filter calculation is performed by, for example, calculating 1/32, 1/16, 1/4, etc., when analog output from the CMOS area sensor 211 is A / D converted into 8-bit, 256-gradation digital data. Do. That is, the noise component of the output from the CMOS area sensor 211 is removed.

  It is determined by video adjustment whether or not sufficient video information is obtained for the next video comparison calculation (S1005). If it is determined that sufficient video information can be obtained, the video comparison calculation described later is performed (S1006). Based on the video comparison calculation result, the paper type is determined from the surface property of the recording material (S1007).

  Next, the above-described video comparison calculation method will be described. In the image comparison calculation, the image on the surface of the recording material is read, and the density value Dmax of the maximum density pixel and the density value Dmin of the minimum density pixel are detected for one line in the direction perpendicular to the conveyance direction of the recording material. , Dmax−Dmin is averaged for each line. That is, when the paper fibers on the surface are sticking like the recording material A, many shadows of the fibers are generated. As a result, the difference between the bright part and the dark part is large, and Dmax−Dmin becomes large. On the other hand, on the surface with high smoothness such as the recording material C, the shadow of the fiber is small and Dmax−Dmin is small.

  In this way, Dmax−Dmin is calculated, and the result is compared with a reference value stored in advance in a memory (not shown) such as an EEPROM to determine the type of the recording material.

Note that the reference value here refers to whether the type of recording material is glossy film, glossy paper (smooth paper), plain paper, etc. (plain paper, thick paper 1, thick paper 2 or thin paper) or rough paper. This is a value for determining whether the paper has a low smoothness. Based on the reference values R5 to R7 (R5 <R6 <R7), the determination is made as follows.
(F) Dmax−Dmin ≦ R5 ··· Glossy film (G) R5 <Dmax−Dmin ≦ R6 ·· Glossy paper (smooth paper) and judgment (H) R6 <Dmax−Dmin ≦ R7 Judgment as paper or the like (plain paper, thick paper 1, thick paper 2 or thin paper) (I) R7 <Dmax−Dmin... Judge as rough paper The result of the above-mentioned video comparison calculation is set as fixing condition setting 3 (S1008). .

  Next, a control flow related to environment detection in the control flow by the control CPU 210 will be described with reference to FIG. First, the temperature in the image forming apparatus is detected by the environment detection unit 124 (S1101), then the humidity is detected (S1102), the environment in which the recording material is placed is determined (S1103), and this environment detection unit is detected. Is set to fixing condition setting 4 based on the temperature and humidity obtained from (S1104).

  Regarding the temperature of the recording material, the higher the temperature, the better the fixing property, and the lower the temperature, the worse the fixing property. The smaller the water content, the better the fixing property and the stronger the recording material. Also, the higher the moisture content, the worse the fixing property and the lower the recording material. Therefore, the fixing conditions are changed according to the calculated moisture content contained in the recording material.

  For example, the fixing condition is changed based on a reference table as shown in FIG. FIG. 12A shows a change value of the temperature setting of the fixing device with respect to the fixing temperature as a reference for the fixing condition setting 1 to the fixing condition setting 4 in each table. In this example, an optimum fixing condition can be obtained by adding a value obtained by adding all the coefficients obtained in each fixing condition setting to the fixing temperature of the reference.

  Further, as shown in FIG. 12B, for the fixing condition setting 1 to the fixing condition setting 4, the coefficient in each table represents the magnification with respect to the recording material conveyance speed as a reference. In this example, the optimum fixing condition can be obtained by multiplying the reference coefficient at the minimum coefficient among the coefficients obtained by setting each fixing condition.

  FIG. 12C shows the ranges of H, N, and L for temperature and humidity in the fixing condition setting 4.

  The fixing condition setting value can be appropriately selected according to the fixing property required for the image forming apparatus. It is also possible to obtain optimum fixing conditions by appropriately combining the setting of the fixing temperature and the conveyance speed.

The fixing condition setting will be specifically described below with reference to FIGS. 12 (a) and 12 (b).
(1) Fixing temperature condition setting A correction value for the default reference fixing temperature is selected based on the temperature change table of FIG.

  First, based on the recording material type determination result, whether or not the recording material is a transparent original (OHP sheet), based on the table of the fixing condition setting 1-T in FIG. ), Select coefficient +5, otherwise (no transmission), select coefficient 0.

  If the document is not a transparent original, the fixing condition is selected based on the determination result of the smoothness of the recording material. That is, based on the fixing condition setting 3-T table, the coefficient is +5 when it is determined to be a glossy film, the coefficient is -2 for smooth paper, the coefficient is 0 for plain paper, and the coefficient is +2 for rough paper. Select.

If it is not a transparent original and the surface quality of the recording material is normal, the fixing condition is selected based on the determination result of the basis weight G of the recording material. That is, based on the fixing condition setting 2-T table, if G ≦ 64 [g / m ² ] (thin paper), the coefficient −5 is selected. In the case of 64 <G ≦ 105 [g / m ² ] (plain paper), the coefficient 0 is selected. When 105 <G ≦ 135 [g / m ² ] (thick paper 1), the coefficient +5 is selected. In the case of 135 <G [g / m ² ] (thick paper 2), the coefficient +10 is selected.

  Then, a coefficient is selected based on the fixing condition setting 4-T table in accordance with the detected temperature / humidity. For example, a coefficient of -2 is selected for H / H (high temperature / high humidity), and a coefficient of +2 is selected for L / L (low temperature / low humidity).

  For example, if the default reference fixing temperature is α ° C., the basis weight is cardboard 2 and the fixing temperature in the H / H environment is α + (10−2) = (α + 8) ° C.

(2) Fixing speed condition setting Further, a correction value for the default reference fixing speed is selected based on the speed change table of FIG.

  First, based on the recording material type determination result, whether or not the recording material is a transparent original (OHP sheet), based on the table of the fixing condition setting 1-S in FIG. ), Select a factor of 0.5, otherwise (no transmission), select a factor of 1.

  If the document is not a transparent original, the fixing condition is selected based on the determination result of the smoothness of the recording material. That is, based on the fixing condition setting 3-S table, the coefficient is 0.5 when it is determined to be glossy film, the coefficient is 1 for smooth paper, the coefficient is 1 for plain paper, and the coefficient is for rough paper. Select 0.5.

If it is not a transparent original and the surface quality of the recording material is normal, the fixing condition is selected based on the determination result of the basis weight G of the recording material. That is, based on the fixing condition setting 2-S table, the coefficient 1 is selected when G ≦ 64 [g / m ² ] (thin paper). When 64 <G ≦ 105 [g / m ² ] (plain paper), the coefficient 1 is selected. When 105 <G ≦ 135 [g / m ² ] (thick paper 1), a coefficient of 0.7 is selected. When 135 <G [g / m ² ] (thick paper 2), a coefficient of 0.5 is selected.

  Then, a coefficient is selected based on the fixing condition setting 4-S table according to the detected temperature / humidity. For example, a coefficient of 1 is selected for H / H (high temperature / high humidity), and a coefficient of 0.8 is selected for L / L (low temperature / low humidity).

  For example, assuming that the default reference fixing speed is β, in a thick paper 1 and L / H (low temperature / high humidity) environment, β × 0.7 × 0.5 = β × 0.35 (35% of the reference speed). Speed).

  In addition to obtaining the fixing speed condition by multiplying each parameter as a method of calculating β, the fixing is performed by comparing the tables to select the minimum value, adding or subtracting between the tables. The speed can be determined.

  As described above, in this embodiment, the fixing temperature and the fixing speed are corrected in consideration of all of the plurality of characteristics (surface property, basis weight, temperature, humidity) of the recording material.

  Further, as shown in FIG. 13, the fixing setting condition 4 sets temperature and humidity independently, and is divided into a fixing setting condition 5 for temperature and a fixing setting condition 6 for humidity, and a coefficient is provided for each. it can.

  As described above, in this embodiment, the amount of transmitted light from the recording material is detected, the type, basis weight, and surface property of the recording material are determined from the detection result, and the temperature and moisture of the recording material are detected from the environment detection means. The content rate is judged. According to the present embodiment, by taking all these determination results into account, the fixing control condition of the predetermined fixing device 122 corresponding to the recording material is read, and the optimum fixing temperature condition corresponding to the state of the recording material is set. A good fixed image can be obtained.

  As described above, it is possible to obtain a good fixed image by performing the fixing process under optimum fixing process conditions for various types of recording materials while improving the usability.

(Second embodiment)
Next, a second embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. In the present embodiment, the structure of the image reading sensor (CMOS area sensor) or the paper type discrimination control flow is the same. In the first embodiment described above, in the calculation method of the transmitted light amount of the recording material, the transmitted light amount is obtained by ignoring the uneven light amount of the transmitting LED 302, whereas in this embodiment, the uneven light amount is taken into consideration (FIG. 15). S1504 to S1508) The amount of light transmitted through the recording material is calculated.

  FIG. 14 shows an image after the received light is read by the CMOS area sensor 211 and digitally processed when the LED 302 is irradiated in the absence of a recording material. This image represents unevenness in the sensitivity of the LED 302 if the sensitivity of the CMOS area sensor 211 is uniform. Moreover, the control flow in a present Example is shown in FIG.

  In the image of FIG. 15 obtained from the light received without passing through the recording material, the amount of light between the pixels is compared (S1504), and the difference ΔPi = (the maximum of ΔPij) of the output values of each pixel i is obtained. A pixel region smaller than a certain value Q is extracted (S1505). Here, ΔPij = Pi−Pj, and Pi and Pj are the density at the pixel i and the density at the pixel adjacent to the pixel i, respectively. In the pixel area smaller than the constant value Q, an average value of the light amount is obtained and stored as a reference value of the transmitted light amount in a memory such as an EEPROM.

  Next, the gain of the transmissive LED 302 is adjusted until the recording material reaches the irradiation area of the transmissive LED 302 (S1506). The gain adjustment is performed by adjusting the gain of the analog output from the CMOS area sensor 211. That is, when the amount of light transmitted through the recording material is too large or too small, the amount of light transmitted through the recording material cannot be read sufficiently, and a change in the amount of transmitted light cannot be detected appropriately, and gain adjustment is performed. Then, the gain of the analog output from the CMOS area sensor 211 is adjusted, the recording material is imaged in the irradiation region of the transmission LED 302, and the average value of the transmitted light amount is calculated in the pixel region where the uneven light amount is extracted as described above. Ask. Thereby, the transmitted light amount of the recording material can be obtained without being affected by the unevenness of the light amount.

  As described above, it is possible to accurately discriminate between thin paper, plain paper, and thick paper by making a relative comparison with the reference value of the transmitted light amount recorded in advance.

(Third embodiment)
In the above embodiment, the light amount is calculated to determine the thickness of the recording paper. However, in this embodiment, a detection element for directly measuring the thickness of the recording paper is separately provided. In other configurations, the same components are denoted by the same reference numerals as in the above embodiment, and the description thereof is omitted.

  In this example, the detection accuracy can be improved by directly measuring the thickness of the recording material. For example, in FIG. 1, there is provided means for measuring the displacement amount of the registration roller when the recording paper is sandwiched between the registration roller pair 126 with reference to the state where the recording paper is sandwiched between the registration rollers 126 (not shown). The thickness of the recording material is directly measured from the displacement amount of the registration roller. Next, a control flow related to thickness detection of the recording material in the control flow by the control CPU 210 will be described with reference to FIG. First, the thickness of the recording material is measured from the displacement amount of the registration roller (S1601). Since the thickness of the recording material is directly measured, each basis weight range of the recording material can be discriminated more finely than in the above embodiment (S1602). The detection result obtained here is set as the fixing condition setting 7 (S1603).

  For example, since the roughness of the recording material is measured in step S1007, the fixing conditions can be changed depending on the thickness of the OHP sheet, glossy film, glossy paper, and rough paper. Specifically, as shown in FIGS. 17A and 17B, it is possible to increase the number of divisions of the basis weight G compared to the reference table used in the above embodiment. Therefore, by replacing the fixing condition setting 7 obtained here with the fixing condition setting 2 of the above embodiment and setting the same fixing condition, it is possible to set the fixing condition finer than the above embodiment. It became. The reference table is not limited to the basis weight G, but can be a table of the recording material thickness L as in the fixing condition setting 7 '.

  As described above, the fixing conditions can be set more finely according to the type of the recording material, and a more stable fixed image can be obtained.

  In this example, the thickness of the recording material is measured from the displacement amount of the registration roller 126. However, a means dedicated to detecting the recording material thickness may be provided separately from the registration roller. In short, a more stable fixed image can be obtained by improving the accuracy of detecting the thickness of the recording material by directly measuring the thickness of the recording material.

(Fourth embodiment)
In this embodiment, a detection means for measuring the moisture content of the recording material is separately provided. In other configurations, the same configurations are denoted by the same reference numerals as those in the above embodiments, and the description thereof is omitted.

  In the present invention, the detection accuracy can be improved by directly measuring the moisture content of the recording material. For example, a water content detection hand throw 125 can be provided as a means for detecting the water content of the recording material. The moisture content detection hand throw 125 is preferably a sensor that detects absorption of infrared rays, microwaves, and the like by moisture contained in the recording material, and for example, a ceramic sensor can be used. As a result, the moisture content of the recording material can be directly detected in real time, and the detection accuracy of the moisture content of the recording material can be improved. Further, the moisture content may be detected from the swelling property, the evaporation heat capacity change, and the electric conductivity.

  Next, the control flow related to the detection of the moisture content of the recording material in the control flow by the control CPU 210 will be described with reference to FIG. First, the moisture content of the recording material is measured using the moisture content detection hand throw 125 (S1801). Since the moisture content of the recording material is directly measured, each basis weight range of the recording material can be set more finely than in the above embodiment (S1802). The detection result obtained here is set as the fixing condition setting 7 (S1803).

  According to this example, since the moisture content of the recording material is directly measured, when the environment changes suddenly or immediately after the recording material is taken out of the wrapping paper, etc., it is not familiar with the surrounding environment. Even when the paper is passed, the moisture content of the recording material can be accurately measured. Therefore, a more stable fixed image can be obtained regardless of environmental changes.

[Second Embodiment]
In addition to the first embodiment, whether or not the recording material wraps around the fixing roller when the unfixed toner image is fixed based on the toner amount and area at the front end in the transport direction of the unfixed toner image formed on the recording material. Determine. If it is determined that the image is wound, the margin length at the tip is adjusted when an unfixed toner image is formed on the recording material. For example, when a solid image with a large amount of toner is present at the leading edge of the recording material, when comparing thick paper and thin paper, the thick paper is less likely to be wound and the thin paper is more likely to be wound. This is because a solid image has a higher adhesion to the surface of the fixing roller and is difficult to separate. Winding also depends on the waist of the recording material, and the lower the waist, the easier it is to wind. In the case of paper, the higher the moisture content, the weaker the paper becomes and the easier it is to wind.

  For example, the fixing condition can be changed based on a reference table as shown in FIGS. For each detection for changing the fixing condition, the above-described means can be used, and the above-described flowchart can be used.

  In the table of FIG. 19, the recording material type and basis weight in the left column are set based on the detection result of the video reading sensor. The first line (environment) from the top of the table is set based on the result of the environment detection. The second line (paper surface roughness) from the top of the table is set based on the detection result of the video reading sensor. In this example, three parameters of speed, fixing temperature, and leading edge margin are handled as one set (third and subsequent lines from the top) as fixing conditions, and the fixing conditions are changed. Here, the speed represents the conveyance speed of the recording material, and the numerical value in the table represents the relative speed with respect to the initial value. The fixing temperature indicates a change value of the set temperature with respect to the initial value. The leading edge margin represents the position of the leading edge of the image with respect to the leading edge of the recording material, and the numerical values in the table indicate the minimum regulation value. When the margin set by the user is larger than the regulation value, the user setting may be prioritized.

The fixing condition setting will be specifically described below with reference to FIG. The fixing condition setting items in each control flowchart are the following (1) to (4), and the description of the same control as described above is omitted.
(1) Recording Material Type The recording material type can be determined by the same control as in FIGS. 9 and 10 as described above. In this example, three types of paper, glossy paper, and OHP sheet are determined.
(2) Basis weight Basis weight can be determined by the same control as in FIGS. 9 and 15 as described above. In this example, eight types of paper and two types of glossy paper are determined.
(3) Environment The environment can be determined by the same control as in FIG. 11 as described above. In this example, H / H (high temperature / high humidity), N / N (normal temperature / normal humidity), and L / L (low temperature / low humidity) are determined.
(4) Paper Surface Roughness The paper surface roughness can be performed by the same control as in FIGS. 9 and 15 as described above. In this example, smooth, normal, and rough are determined.

  As described above, the fixing conditions are set based on the determination results (1) to (4). Here, three specific examples will be described.

In the first example, the recording material type is determined as “paper” from the result of (1), and the basis weight is determined as “65 <G ≦ 80 [g / m ² ]” from the result of (2). ), The environment is determined as “H / H”, and the paper surface roughness is determined as “smooth” from the result of (4). In this case, the fixing condition setting is “speed: 1/1 speed, fixing temperature: −5 ° C., leading edge margin: 3 mm”.

As a second example, the recording material type is determined as “glossy paper” from the result of (1), the basis weight is determined as “100 <G [g / m ² ]” from the result of (2), and (3) In this case, the environment is determined as “L / L” from the result of (4), and the paper surface roughness is determined as “smooth” from the result of (4). In this case, the fixing condition setting is “speed: 1/2 speed, fixing temperature: + 10 ° C., leading edge margin: 0 mm”. In this example, since the result of (4) is set to be included in the result of (1), “normal” and “rough” of the paper surface roughness are not selected.

  As a third example, the recording material type is determined as “OHP sheet” from the result of (1), and the environment is determined as “L / L” from the result of (3). In this case, the fixing condition setting is “speed: 1/2 speed, fixing temperature: + 10 ° C., leading edge margin: 0 mm”. In the case of an OHP sheet, there is no determination of (2) and (4) from the control flow.

As described above, the characteristics of the recording material can be detected by various detection means, and one or more fixing conditions can be set using the reference table.
As described above, the fixing roller is adjusted by adjusting the margin length at the leading edge when forming an unfixed toner image on the recording material as in the present example with respect to the paper state determined in the first embodiment. Winding around can be prevented in advance. Therefore, it is possible to obtain a good fixed image by performing the fixing process under the optimal fixing process condition for various types of recording materials while improving the usability.

  When the paper thickness detection unit is used to detect the paper thickness as shown in FIG. 16, the basis weight G shown in the second column from the left in FIG. 19 is replaced with the thickness L as shown in FIG. be able to. In this case, since the thickness can be directly measured, the determination accuracy can be improved. Furthermore, since the thickness of the OHP sheet can be measured, as shown in FIG. 20, a reference table corresponding to the thickness of the OHP sheet can be added to set fixing conditions with higher accuracy.

  In this example, the division condition of each detection result is not limited, and the number of detection result divisions can be increased or decreased as necessary. In addition, the above-described water transportation amount detection result can be reflected in the fixing condition.

[Other embodiment examples]
Another embodiment of the present invention will be described with reference to FIGS. Since the operation method and the control method are the same as those in the first embodiment described above, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and only the configuration different from the first embodiment is described. To do.

  In FIG. 21, the sensor unit 1301 has a substrate 1302 on which a reflective LED 301, a transmissive LED 1303, and a sensor chip 211 are mounted, and includes a lens 303. At this time, the reflective LED 301 is mounted obliquely with respect to the substrate 1302, as shown in FIG. However, it is also possible to irradiate the LED diagonally with a light guide (not shown) without mounting the LED diagonally.

  Light output from the transmissive LED 1303 mounted on the substrate 1302 is repeatedly reflected by the light guide 1304, and the recording material is irradiated with light from the opposite side of the sensor. Thereby, an effect equivalent to the transmissive LED 302 in the first embodiment example or the second embodiment example can be achieved.

  According to the present embodiment, the electrical components can be concentrated and arranged in one direction with respect to the recording material, so that the cost can be reduced and the restrictions on the wiring path and the attachment can be eased.

  In FIG. 22, the sensor unit 1401 includes a substrate 1403 on which a transmissive / reflective LED 1403 and a sensor chip 211 are mounted, and includes a lens 303 and a prism 1404.

  The light output from the transmission / reflection LED 1403 mounted on the substrate 1402 is divided into reflection light and transmission light by the prism 1404. The light for reflection illuminates the detection area, and the light for transmission is repeatedly reflected by the light light guide 1405, and the recording material 304 is irradiated with light from the opposite side of the sensor. Thereby, an effect equivalent to the transmissive LED 302 in the first embodiment example or the second embodiment example can be achieved.

  According to the present embodiment, the electrical components can be concentrated and arranged in one direction with respect to the recording material, and the number of light sources can be reduced, so that the cost can be reduced and the wiring path is restricted. And the ease of installation can be relaxed.

  In the present invention, the user can directly set the basis weight and roughness information of the recording material, and the user can set the mode that prioritizes the conditions set by the user and the mode that prioritizes the result detected by the image forming apparatus. It can also be made selectable.

1 is a schematic configuration diagram illustrating an image forming apparatus used in an embodiment of the present invention. It is a block block diagram which shows the structure of each unit which control CPU by one Embodiment of this invention controls. FIG. 3 is a schematic diagram illustrating a schematic configuration for performing surface smoothness of a recording material and detection of a reflected light amount and a transmitted light amount. It is a figure which shows contrast with the analog image of the recording material surface read by an image | video reading sensor, and the digital image which digitally processed the analog output to 8x8 pixel. It is the figure which digitally processed and displayed the image of the recording material read by the image | video reading sensor to 8x8 pixel using LED for permeation | transmission. FIG. 6 is a characteristic diagram illustrating the relationship between the basis weight of a recording material and transmitted light. It is a block block diagram which shows the control circuit of the CMOS area sensor by one Embodiment of this invention. It is a block block diagram which shows the circuit structure of the CMOS area sensor by one Embodiment of this invention. 3 is a flowchart illustrating a control flow by a control CPU that executes fixing process condition control provided in the image forming apparatus according to the first embodiment. 3 is a flowchart illustrating a control flow by a control CPU that executes fixing process condition control provided in the image forming apparatus according to the first embodiment. 3 is a flowchart illustrating a control flow by a control CPU that executes fixing process condition control provided in the image forming apparatus according to the first embodiment. FIG. 6 is a diagram illustrating a fixing condition change table for executing fixing processing condition control provided in the image forming apparatus according to the first embodiment. FIG. 6 is a diagram illustrating a fixing condition change table for executing fixing processing condition control provided in the image forming apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an image after light received by an LED in the absence of recording paper is read by a CCD sensor and digitally processed. 12 is a flowchart illustrating a control flow by a control CPU that executes fixing process condition control provided in an image forming apparatus according to a second embodiment. 12 is a flowchart showing a control flow related to thickness detection of a recording material in a control flow by a control CPU 210 that executes fixing process condition control provided in an image forming apparatus according to a third embodiment. FIG. 10 is a diagram illustrating a fixing condition change table for executing fixing processing condition control provided in an image forming apparatus according to a third embodiment. 12 is a flowchart illustrating a control flow by a control CPU that executes fixing process condition control provided in an image forming apparatus according to a third embodiment. FIG. 10 is a diagram illustrating a fixing condition change table for executing fixing processing condition control provided in an image forming apparatus according to a fourth embodiment. FIG. 10 is a diagram illustrating a modification of a fixing condition change table for executing fixing processing condition control provided in an image forming apparatus according to a fourth embodiment. It is typical sectional drawing which shows schematic structure of other embodiment. It is typical sectional drawing which shows schematic structure of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Image forming apparatus 102 ... Paper cassette 103 ... Paper feed roller 104 ... Transfer belt drive roller 105 ... Transfer belt 106-109 ... Each sensitivity of yellow, magenta, cyan, and black Drums 110 to 113... Transfer rollers 114 to 117 for each color... Yellow, magenta, cyan, and black cartridges 118 to 121... Yellow, magenta, cyan, and black optical units 122. Device 123... Image reading sensor 124... Environment detection means (temperature sensor and humidity sensor)
125: Moisture content detection means 126: Registration roller 210: Control CPU
211 ... CMOS area sensors 212 to 215 ... polygon mirror, motor and laser 216 ... paper feed motor 217 ... paper feed solenoid 218 ... paper presence sensor 219 ... high voltage power supply 220 ... -Drum drive motor 221 ... Belt drive motor 222 ... Low voltage power supply 223 ... ASIC
224 ... Memory 225 ... Thermistor 226 ... Heat source 301 ... Reflecting LED
302 ... LED for transmission
303 ... lens 304 ... recording material 702 ... control circuit 704 ... interface control circuit 705 ... arithmetic circuit 706 ... register A
707: Register B
708... Control register 801... CMOS sensor portion 802 803. Vertical shift register 804... Output buffer 805 .. horizontal shift register 806. ... A / D converter 809 ... Output interface circuit 810 ... Sl_out signal 811 ... Control circuit 812 ... Sl_in signal 813 ... Sl_select signals 1301, 1401 ... Sensor units 1302, 1402 ..Boards 1303, 1403 ... LED
1304, 1405 ... Light guide 1404 ... Prism

Claims (4)

Transfer means for transferring an image to a recording material;
A fixing unit for fixing the image transferred to the recording material,
Recording material information detecting means for detecting information on the surface property of the recording material and information on the thickness;
Environmental detection means for detecting environmental information;
Based on the information on the surface property, the information on the thickness, and the environmental information, the amount of margin at the tip when the image is transferred to the recording material by the transfer unit, and the image on the recording material by the fixing unit And a processing means for setting a heating temperature when fixing the recording material and a conveyance speed of the recording material ,
The transfer unit transfers an image to the recording material based on the leading edge margin amount set by the processing unit , and the fixing unit sets the heating temperature and the conveyance speed set by the processing unit. An image forming apparatus for fixing an image transferred to the recording material on the basis of the image forming apparatus. The image forming apparatus according to claim 1, wherein the environment detecting unit detects information related to temperature and humidity in the image forming apparatus as the environment information. The processing unit obtains a moisture content of the recording material from the detected environmental information, and calculates a fixing condition when the fixing unit fixes an image on the recording material based on the obtained moisture content. The image forming apparatus according to claim 1, wherein the image forming apparatus performs processing. An image forming method for an image forming apparatus , comprising: a transfer unit that transfers an image to a recording material; and a fixing unit that fixes an image transferred to the recording material.
A recording material information detecting step for detecting information relating to the surface property of the recording material and information relating to the thickness of the recording material;
An environmental information detection step of detecting environmental information of the image forming apparatus;
Based on the information on the surface property of the recording material, the information on the thickness of the recording material, and the environmental information, the amount of margin at the tip when the image is transferred to the recording material by the transfer means, and the fixing means A setting step for setting a heating temperature and a conveyance speed of the recording material when fixing an image on the recording material by :
A transfer step of transferring an image to the recording material based on the leading edge margin amount set in the setting step;
A fixing step of fixing the image transferred to the recording material in the transfer step to the recording material based on the heating temperature and the conveyance speed set in the setting step ;
An image forming method comprising:

Images