JP2005234472A - Recording-material discrimination apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve fixing, etc., under the optimum fixing conditions even on various types of recording materials while improving usability by highly accurately discriminating the type of the recording material. <P>SOLUTION: An image reading sensor 123 includes a reflecting LED 301, an LED 303 which is disposed opposite from recording material 304 and detects transmitted light quantity, a CMOS area sensor 211, and an image forming lens 303. Light from the reflecting LED 301 as a light source is emitted to the surface of the recording material 304. The light reflected from the recording material 304 is condensed via the lens 303 and forms an image in the CMOS area sensor 211. In such a case, a diffusing plate or a diffusible light guide is used between a transmitting LED 302 and the recording material 304. This removes irregularities in the light source and improves measuring accuracy. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a recording material determination device and an image forming apparatus. More specifically, the present invention relates to a recording material determination device and an image forming apparatus that detect the reflected light from the surface of a recording material and the amount of light transmitted through the recording material to determine the type. About.

  Image forming apparatuses such as copying machines and laser printers fix the developer image by transferring an image visualized and developed by a developing unit to a recording material and heating and pressing under predetermined fixing processing conditions. The predetermined fixing conditions vary greatly depending on the material, thickness, surface treatment, and the like of the recording material. Therefore, in order to use a plurality of types of recording materials, fine setting according to the type of the recording material is required.

  Conventionally, in such an image forming apparatus, for example, a user sets for each printing by a printer driver displayed on a computer, or the size and type of a recording material (recording material on an operation panel or the like provided in the main body of the image forming apparatus). If the paper is paper, the user sets the paper type), and the fixing processing conditions (for example, the fixing temperature and the conveyance speed of the recording material passing through the fixing device) are changed according to the setting.

  For this reason, in recent years, the type of recording material is automatically determined using a sensor for determining the recording material inside the image forming apparatus, and development conditions, transfer conditions, or fixing conditions are variably controlled according to the determined type. Techniques to do this have been proposed.

  In such a technique for automatically detecting the type of recording material, for example, a surface image of the recording material is captured by a CCD sensor, and this information is converted into fractal dimension information to detect the surface smoothness of the recording material. A method is proposed in which a surface image of a recording material is picked up by a CCD sensor or a CMOS sensor, the roughness of the recording material is detected from the magnitude relationship of the light, and the paper type is discriminated from the surface smoothness. For example, see Patent Document 1).

JP 2002-182518 A

  However, the above-described method for determining the type of recording material based on the surface smoothness of the recording material determines that the thick paper is plain paper in, for example, plain paper and thick paper when the surface smoothness is the same in recording materials having different thicknesses. The development conditions, fixing conditions, and transfer conditions cannot be set to be suitable for the recording paper.

  On the other hand, in the method of determining only the thickness of the recording material, since the smoothness of the surface of the recording material is not known, a recording material having a different surface smoothness, such as gloss paper, may be determined as plain paper, Since the development conditions, the fixing conditions, and the transfer conditions cannot be set appropriately for the recording paper, there is a problem that the fixing property is deteriorated.

  Further, in recent years, despite the variety of types of recording materials, the demand for print quality is higher, and it is required to accurately discriminate a wide variety of recording materials. In order to solve this problem, in the present invention, both surface smoothness and material thickness detection are realized with an inexpensive configuration.

  However, although it is required to determine the type of the recording material with high accuracy, the accuracy may be deteriorated due to variations in the characteristics of the detection components, particularly in the detection of transmitted light amount.

  The present invention has been made in view of such a problem, and provides a recording material discriminating apparatus and an image forming apparatus capable of automatically discriminating various types of recording materials with high accuracy and performing image formation under appropriate conditions. The purpose is to provide.

  In order to achieve the above object, the present invention includes an image reading means for obtaining an image of a recording material surface by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material. In a recording material discriminating apparatus, comprising a reflection type determining means for determining a predetermined attribute of the recording material using an image on the surface of the recording material, and determining the type of the recording material based on the attribute obtained by the reflection type determining means A transmission type determination means for determining an attribute different from the reflection type determination means of the recording material by using the transmitted light obtained by irradiating the recording material with a predetermined irradiation light, and reflecting In addition to the attribute obtained by the type determining means, the type of the recording material is determined based on the attribute obtained by the transmission type determining means.

  In order to accurately determine the transmitted light in the present invention, first, the image reading means is constituted by a plurality of image sensors and the transmitted light is detected, so that the recording material is stabilized regardless of partial unevenness of the recording material. The amount of transmitted light can be measured. Secondly, in order to perform highly accurate detection in each of the plurality of imaging elements, it is necessary to reduce unevenness in the amount of light due to the deviation of the light emission distribution of the light source that transmits the recording material. For this reason, the present invention is characterized in that transmitted light detection is performed with high accuracy by disposing a diffusion plate between the light source and the recording material and removing unevenness of the light source.

  Further, in the detection control, the detection light quantity is calibrated in advance in order to reduce errors due to characteristic variations of light-emitting elements, light-receiving elements, and optical components such as lenses. At this time, in order to increase the calibration accuracy, the diffusion plate is provided, and the diffusion performance of the diffusion plate is uniform at a level that disperses the light emission unevenness of the light emitting elements and does not saturate the received light amount data of the plurality of light receiving elements. It is characterized by a diffusion performance that can obtain a sufficient amount of light.

  According to the present invention, it is possible to detect transmitted light with high accuracy by disposing a diffusion plate between a light source and a recording material and removing unevenness of the light source.

  Also, by calibrating the detected light quantity, when detecting the recording material, it is possible to obtain a highly accurate transmittance regardless of variations in the light emitting element, light receiving element, optical system, etc., by comparing with the light quantity at the time of calibration. Therefore, it is possible to realize an accurate transmission type determination unit.

  According to the present invention, the type of the recording material can be accurately determined, so that a good fixed image can be obtained by performing fixing or the like on various types of recording materials under optimum fixing processing conditions while improving usability. Can do.

  Hereinafter, a recording material discriminating apparatus and an image forming apparatus according to the present invention will be described with reference to the drawings.

<Embodiment 1>
(Image forming device)
The recording material discriminating apparatus of the present invention is used in a general image forming apparatus as shown in FIG. In FIG. 1, an image forming apparatus 101 includes a paper cassette 102, a paper feed roller 103, a transfer belt driving roller 104, a transfer belt 105, yellow, magenta, cyan, and black photosensitive drums 106 to 109, and a transfer roller 110 for each color. , 113, yellow, magenta, cyan, and black cartridges 114 to 117, yellow, magenta, cyan, and black optical units 118 to 121, and a fixing unit 122, respectively.

  The image forming apparatus 101 generally transfers an image of yellow, magenta, cyan, and black on a recording material using an electrophotographic process, and controls the temperature of the toner image transferred by a fixing unit 122 including a fixing roller. Heat fix. 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. 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.

  Further, the image forming apparatus 101 includes a paper feed motor that feeds and transports recording paper as a recording material, and the fed recording paper is transported to a transfer belt and a fixing roller on a surface thereof as desired. Form an image.

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

  A control CPU 210 which is a control unit of the image forming apparatus 101 described below with reference to FIG. 2 applies a desired amount of heat to the recording material by the fixing unit 122 to fuse and fix the toner image on the recording material. .

  Next, the operation of the control CPU of one embodiment of the recording material discrimination apparatus and the image forming apparatus using the method of the present invention 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 CPU 210 is connected to a CMOS sensor 211 and polygon mirrors, motors, and lasers 212 to 215 included in each color optical unit, and scans the laser on the photosensitive drum surface to draw a desired latent image. Control the optical unit. Similarly, a paper feed motor 216 for transporting the recording material, a paper feed solenoid 217 used to start driving a paper feed roller for feeding the recording material, and whether or not the recording material is set at a predetermined position. A paper presence sensor 218 to detect, a primary charging necessary for an electrophotographic process, development, primary transfer, a high voltage power source 219 for controlling a secondary transfer bias, a drum driving motor 220 for driving a photosensitive drum and a transfer roller, a transfer belt, The belt driving motor 221 for driving the roller of the fixing unit, the fixing unit and the low voltage power supply unit 122 are controlled. Further, the control CPU 210 monitors the temperature with a thermistor (not shown) and performs control 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 includes all of the above-described control and processing performed by the control CPU 210 in each embodiment described in this specification. A program and data for executing a part are stored. 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 control CPU 210 is connected to the memory 223 by a bus or the like (not shown). The memory 223 stores all of the above-described control and processing performed by the control CPU 210 in each embodiment described in the present specification. A program and data for executing a part are stored. That is, the control CPU 210 executes the operations of the embodiments of the present invention using the program and data stored in the memory 223.

  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 configured by a circuit based on the hardware of the ASIC 223 so that the control load on the 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 a paper presence sensor 218, and if there is paper, the paper feed motor 216, drum drive motor 220, The belt driving motor 221 is driven, and the sheet feeding solenoid 217 is driven 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, and the CMOS sensor 211 captures a surface image of the recording material. At this time, the ASIC 223 activates Sl_select, outputs SYSCLK of a predetermined pulse at a predetermined timing, and captures imaging data output from the CMOS sensor 211 via Sl_out.

  On the other hand, the gain setting of the CMOS sensor 211 is performed 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 outputs SYSCLK of a predetermined pulse at a predetermined timing. A gain is set for the CMOS sensor 211 via Sl_in.

  The ASIC 223 includes a recording material discriminating apparatus and a circuit based on a first arithmetic unit and a second arithmetic unit for realizing the recording material discriminating apparatus of the present invention described below, and each arithmetic result is stored in a register in the ASIC 223. Stored. Then, the CPU 210 reads the register in the ASIC 223, determines the type of the fed recording material, and controls to change the developing bias condition of the high voltage power source 219 according to the result.

  For example, in the case of so-called rough paper where the surface fibers of the recording material are rough, control is performed to prevent toner scattering by lowering the developing bias than plain paper and suppressing the amount of toner adhering to the surface of the recording material. This is because the amount of toner adhering to the surface of the recording material is large especially in the case of rough paper, so that the problem that the image quality deteriorates due to the scattering of the toner due to the paper fibers is solved.

  Further, the CPU 210 determines the type of the fed recording material and controls to change the temperature condition of the fixing unit 222 according to the result. For example, in the case of the rough paper, there are rough papers with poor toner fusing properties due to the rough surface fibers, and therefore there are cases where optimization is attempted by changing the fixing temperature. In the case of OHT, if the fixing property of the toner adhering to the surface of the recording material is poor, there is an effect on the problem that the permeability of OHT is deteriorated.

  Further, the CPU 210 determines the type of the fed recording material, and controls to change the recording material conveyance speed 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 CPU 210. Change the fixing temperature conditions for recording materials with different basis weights. For example, recording materials with a relatively large thickness have a large heat capacity, so the fixing temperature is controlled to be high, while recording with a relatively small thickness, that is, a small heat capacity. The material is fixed at a lower fixing temperature. Alternatively, the recording material conveyance speed can be changed and controlled according to the basis weight of the recording material.

  In the case of OHT 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 and increasing the gloss.

  As described above, in this embodiment, the first calculation and the second calculation are performed by the ASIC hard circuit from the surface image of the recording material imaged by the CMOS area sensor. Alternatively, it can be controlled to change the control temperature condition of the fixing unit or the conveyance speed of the recording material.

  Next, a recording material discrimination device according to an embodiment of the present invention will be described. FIG. 3 and FIG. 10 are schematic diagrams showing a schematic configuration for detecting the surface smoothness of the recording material, the amount of reflected light and the amount of transmitted light, and best represent the present invention.

  As shown in FIG. 3, the image reading sensor 123 is a second LED for transmissive light amount detection, which is disposed on the opposite side to the reflective LED 301 and the recording material 304, which are first irradiators. An LED 302, a CMOS area sensor 211 as a reading unit, and an imaging lens 303 are provided. Here, the sensor 211 may be 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. . 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 whose surface paper fibers are relatively rough, the recording material B402 is a commonly used so-called plain paper, and the recording material C403 is sufficiently compressed with paper fibers. It is gloss paper, and is a magnified image of each 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, but 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 above-mentioned recording material surface is identified by reading images at a plurality of locations, detecting the pixel density Dmax and the pixel density Dmin having the lowest density in each image, and averaging the values obtained at the plurality of locations. . Based on Dmax and Dmin averaged for each recording material, the material (smoothness) that is an attribute of the recording material can be determined.

  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.

  Similarly, 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 paper D which is a thin paper, and the image 408 is generally used. A surface enlarged image of the light irradiation region by the transmission LED 302 of the recording paper E which is so-called plain paper, and an image 409 is a surface expansion image of the light irradiation region by the transmission LED 302 of the recording paper F which is a thick paper. These images 407 to 409 read into the CCD sensor 211 are digitally processed to become images 410 to 412 in FIG.

  In this way, the amount of transmitted light and its image vary depending on the type of recording paper. 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 above-described control processor needs to process 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 using the transmitting LED 302 as the second irradiation unit as a light source is irradiated 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. The

  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 by digitally processing the output from the CMOS area sensor 211 into 8 × 8 pixels. . 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.
(1) Thin paper (basis weight: weight per unit area to 64 g / m ² )
(2) Plain paper (basis weight: 65 to 105 g / m ² )
(3) Cardboard 1 (basis weight: 106-135 g / m ² )
(4) Cardboard 2 (basis weight: 136 / m ² ~)
(5) Gloss paper (6) Gloss film (7) OHT
Since (7) is transparent and has high light transmittance, two sets (1) to (6) and (7) are determined based on the amount of light reflected from the recording material.

  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 is performed based on the amount of reflected light. 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 64 × 64 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 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 for storing the calculation result of the unevenness on the recording material surface, and an uneven edge on the recording material surface. A register B707 and a control register 708 for storing the quantity calculation result are provided.

  Next, the operation will be described.

  When the CPU 210 gives an operation instruction of the CMOS area sensor 211 to the control register 708, the CMOS area sensor 211 starts to capture the recording material surface image. 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 based on a first calculation method to be described later, and the result is stored in the register A 706 as the unevenness calculation result on the surface of the recording material. On the other hand, the result calculated by the control circuit 702 based on the second calculation method, which will be described later, from the imaging data received via the interface circuit 704 is stored in the register B 707 as the result of calculating the uneven edge amount on the surface of the recording material. . The CPU 210 determines the surface smoothness of the recording material from the values of the two registers.

  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. In FIG. 8, a CMOS area sensor 211 includes a CMOS sensor portion 801, and, for example, sensors for 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 active, the CMOS sensor unit 801 starts to accumulate charges based on the received light. Next, when the system clock 806 is given, 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.

  The 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 control 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 CPU can always capture with the best contrast by changing the gain.

  As described above, by using the two irradiation means, that is, the reflection LED 301 as the first irradiation means and the transmission LED 302 as the second irradiation means, the surface state, reflectance, and transmittance of various recording materials. Can be detected, and the type of recording material can be determined.

  In such a configuration, in order to accurately discriminate the transmitted light amount, in the present configuration in which the light amount measurement is performed with a plurality of light receiving elements, it is necessary to provide a configuration that provides uniform irradiation with little unevenness in the light amount. In the present invention, in order to obtain such an irradiation light amount, it is proposed that a diffuser plate is provided at an intermediate position between the transmitted light source and the light receiving element to reduce unevenness in light emission of the transmitted light source. If a uniform amount of light can be obtained, it is possible to set a light receiving sensitivity with a wide dynamic range in a plurality of light receiving elements, which is preferable because a measurement error is reduced and a calculation error is also reduced.

  Further, the embodiment will be described with respect to the position of the diffusion plate.

  The diffusion plate is arranged at a position close to the light receiving element with respect to the light emitting element and the light receiving element. The reason is that if the diffusion plate is arranged on the side close to the light emitting element, the luminance distribution in the vicinity of the element is projected onto the diffusion plate, and it is difficult to obtain uniform diffusibility. On the other hand, if the diffuser plate is disposed on the side closer to the light receiving element, the light directed to the light receiving element can be dispersed at the position where the light receiving element takes an image without being affected by the luminance unevenness of the light emitting portion.

  Further, the position of the diffusion plate is a position where light irradiation by the light emitting element for detecting the surface property is not performed. For example, as shown in FIG. 9, when a diffuser plate is disposed immediately behind the recording material, the diffuser plate is irradiated by the light emitting element for detecting the surface property when detecting the surface property, and the surface property is affected by the reflected light from the diffuser plate. Detection has measurement error. In particular, in the case of a highly transmissive recording material such as OHT, there is a possibility that it will be identified as plain paper depending on the amount of light reflected by the diffusion plate. Therefore, as shown in FIG. 10, the position of the diffusion plate in the present invention needs to be such that the light emitted from the light source does not hit the diffusion plate. The recording material is characterized in that it is arranged at a position more than the distance that does not affect the surface property detection of the recording material.

  The present invention enables highly accurate detection and measurement by calibrating the next detection unit under a homogeneous light source.

  Next, details of the light quantity calibration method will be described.

  First, when the recording material is not in the detection unit, the amount of light in the detection configuration unit is measured. At this time, if there is unevenness in the amount of light, the data may be saturated in the result of A / D converted light amount measurement. Further, if the light emission amount of the light emitting element is lowered so that the light amount is not saturated, the light amount is insufficient in some of the light receiving elements, and the measurement dynamic range is narrowed, so that the accuracy is lowered. Therefore, it is indispensable to homogenize the light source by the aforementioned diffusion plate.

  As described above, using the two irradiation means of the reflection LED for photographing the recording material surface as the reflection light irradiation means and the transmission LED as the transmission light irradiation means for detecting the thickness of the recording material by the transmitted light, and By using a diffusion means in the space between the transmissive light irradiating means and the recording material to homogenize the light of the transmissive light irradiating means, the surface properties, reflectance and transmittance of various recording materials can be accurately measured. The recording material type can be determined.

<Embodiment 2>
In the present embodiment, the basic configuration other than the configuration of the transmitted light detection unit is the same as that of the first embodiment, and thus detailed description thereof is omitted. In this embodiment, a light source used for transmission light detection is proposed.

  In this embodiment mode, an element having high diffusibility is used as a light source. For example, it is intended to reduce unevenness in the amount of light detected by a light receiving unit by adopting a light source for transmitted light as an LED having a dispersed orientation with low radiation directivity or an LED using milky white resin. To do. This configuration is shown in FIG. However, in this case, when observed from the light receiving side, the luminance unevenness is dispersed in the inner portion of the outline of the LED as the light source, but the periphery of the light source remains a dark portion. When the imaging area is wide, there is a difference between the bright part of the light source and the dark part of the light source peripheral part. In the dark part, the dynamic range at the time of measurement is reduced, and the measurement accuracy is lower than in the first embodiment. However, in the embodiment having a margin of required accuracy, it may be sufficient to reduce the luminance unevenness of the bright part, and it is not necessary to separately provide a diffusion plate, and therefore this embodiment can be applied.

  As described above, using the two irradiation means of the reflection LED for photographing the recording material surface as the reflection light irradiation means and the transmission LED as the transmission light irradiation means for detecting the thickness of the recording material by the transmitted light, and By using a highly diffusive element for the transmissive light irradiating means, it is possible to accurately detect the surface property state, reflectance and transmittance of various recording materials and to determine the type of the recording material.

<Embodiment 3>
In the present embodiment, the basic configuration other than the configuration of the transmitted light detection unit is the same as that of the first embodiment, and thus detailed description thereof is omitted. In this embodiment, a light source used for transmission light detection is proposed.

  This embodiment is characterized in that a light guide member having high diffusibility is used. In the configuration of the present embodiment shown in FIG. 12, the resin member receives light emitted from the light source for transmitted light and has a transmission performance for guiding the light to the vicinity of the surface of the recording material. Call it. Such a light guide generally uses a highly permeable resin such as acrylic. By imparting diffusibility to this light guide, it becomes possible to have both light guide performance and diffusion performance, and the number of parts is reduced, so that high-performance detection control can be realized at low cost.

  As described above, using the two irradiation means of the reflection LED for photographing the recording material surface as the reflection light irradiation means and the transmission LED as the transmission light irradiation means for detecting the thickness of the recording material by the transmitted light, and By using a highly diffusive element for the transmissive light irradiating means, it is possible to accurately detect the surface property state, reflectance and transmittance of various recording materials and to determine the type of the recording material.

<Embodiment 4>
Regarding the application example of the diffusing member having the diffusing performance in the first embodiment and the light guide member having the diffusing property in the third embodiment, it is described that a milky white member is used in order to realize the diffusing performance. An embodiment for realizing other diffusion performance in the third embodiment will be described. The configuration is the same as that of the third embodiment, and will be described with reference to FIG.

  A method is proposed in which the diffusion member is processed to reduce the surface roughness. A member having diffusion performance can be formed by using a transparent member by forming a so-called texture that processes fine irregularities on the surface of the diffusion member, or roughening the surface by sandblasting after processing. This is also effective for the light guide member in the third embodiment. Whether a translucent member or a member with a rough surface is used depends on the required accuracy of diffusion performance, and basically the same effect can be obtained by either method.

<Embodiment 5>
In the present embodiment, the basic configuration other than the configuration of the transmitted light detection unit is the same as that of the first embodiment, and thus detailed description thereof is omitted. In this embodiment, a light source used for transmission light detection is proposed.

  In the present embodiment, the use of a light guide member having diffusibility is the same as in the third or fourth embodiment. These resin members receive light emitted from a light source for transmitted light and have a transmission performance for guiding light to the vicinity of the surface of the recording material, which is called a light guide. The configuration of the present embodiment is characterized in that the light guide has a reflecting surface inside and changes the direction of light as shown in FIG. Such a light guide member is generally made of a highly permeable resin such as acrylic. By imparting diffusibility to the light guide member, it becomes possible to have both light guide performance and diffusion performance, and the number of parts is reduced, so that high-performance detection control can be realized at a low cost. Since the direction of the light can be changed, the space can be effectively utilized by utilizing the reflection characteristics even when the diffuser plate cannot be disposed in the straight optical path due to the configuration.

  As described above, using the two irradiation means of the reflection LED for photographing the recording material surface as the reflection light irradiation means and the transmission LED as the transmission light irradiation means for detecting the thickness of the recording material by the transmitted light, and By using a highly diffusive element for the transmissive light irradiating means, it is possible to accurately detect the surface property state, reflectance and transmittance of various recording materials and to determine the type of the recording material.

<Embodiment 6>
In the present embodiment, the basic configuration other than the configuration of the transmitted light detection unit is the same as that of the first embodiment, and thus detailed description thereof is omitted. In this embodiment, a light source used for transmission light detection is proposed.

  The present embodiment proposes to use a reflecting member having diffusibility. This reflecting member material receives light emitted from the light source for transmitted light and reflects it to the detection surface position of the recording material. As shown in FIG. 14, the configuration of this embodiment has a structure in which the direction of light is changed by a reflecting member, and the reflecting member is not a mirror surface but has a diffusivity. Such a reflecting member can be realized by using a resin having surface roughness or a resin having irregular reflection characteristics such as white. Since the direction of the light can be changed, the space can be effectively utilized by utilizing the reflection characteristics even when the diffuser plate cannot be disposed in the straight optical path due to the configuration.

  As described above, using the two irradiation means of the reflection LED for photographing the recording material surface as the reflection light irradiation means and the transmission LED as the transmission light irradiation means for detecting the thickness of the recording material by the transmitted light, and By homogenizing the light of the transmissive light irradiating means using a diffusive reflecting member in the space between the transmissive light irradiating means and the recording material, the surface condition, reflectance and transmission of various recording materials The rate can be detected with high accuracy, and the type of recording material can be determined.

  INDUSTRIAL APPLICABILITY The present invention is useful for a recording material discriminating apparatus that detects reflected light and a transmitted light amount of a recording material from the surface of the recording material and discriminates the type thereof, and an image forming apparatus including the same.

1 is a schematic diagram showing an image forming apparatus used in Embodiment 1 of the present invention. It is a figure which shows the structure of each unit which control CPU by Embodiment 1 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 using LED for permeation | transmission to 8x8 pixel. It is a figure which shows the relationship between the basic weight of a recording material, and transmitted light. It is a block diagram which shows the control circuit of the CMOS area sensor by Embodiment 1 of this invention. It is a figure which shows the circuit block diagram of the CMOS area sensor by Embodiment 1 of this invention. It is explanatory drawing of a structure of the diffusion plate relevant to this invention. It is explanatory drawing of the structure of the diffusion plate in Embodiment 1 of this invention. It is structure explanatory drawing in Embodiment 2 of this invention. It is composition explanatory drawing in Embodiment 3 and 4 of this invention. It is structure explanatory drawing in Embodiment 5 of this invention. It is structure explanatory drawing in Embodiment 6 of this invention.

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 photosensitive drum of yellow, magenta, cyan, black 110-113 Transfer roller for each color 114-117 Yellow, magenta, cyan, Black cartridges 118 to 121 Yellow, magenta, cyan, and black optical units 122 Fixing unit 123 Image reading sensor 210 Control CPU
211 CMOS sensor 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 301 LED for reflection
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 part 802 803 Vertical shift register 804 Output buffer 805 Horizontal shift register 806 System clock 807 Timing generator 808 A / D converter 809 Output interface circuit 810 Sl_out signal 811 Control circuit 812 Sl_in signal 813 Sl_select signal

Claims (10)

Including image reading means for obtaining an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and using the image of the surface of the recording material obtained by the image reading means In the recording material discriminating apparatus for determining the type of the recording material based on the attribute obtained by the reflection type judging means, comprising a reflection type judging means for judging a predetermined attribute of the recording material,
A light irradiating means for irradiating the recording material with predetermined irradiation light is provided, a member having diffusibility is disposed between the light path between the light irradiating means and the recording material, and transmitted light obtained by transmitting the recording material is transmitted. Using a transmission type determination unit that determines an attribute different from the reflection type determination unit of the recording material, and in addition to the attribute obtained by the reflection type determination unit, the attribute obtained by the transmission type determination unit The recording material discriminating apparatus which discriminates the type of the recording material based on the above. Including image reading means for obtaining an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and using the image of the surface of the recording material obtained by the image reading means In the recording material discriminating apparatus for determining the type of the recording material based on the attribute obtained by the reflection type judging means, comprising a reflection type judging means for judging a predetermined attribute of the recording material,
The recording material is provided with light irradiation means for irradiating the recording material with predetermined irradiation light, and the light irradiation means uses a light source with low directivity or a light source with a milky white resin lens with high diffusibility, A transmission type determination unit for determining an attribute different from the reflection type determination unit of the recording material using transmitted light obtained by transmission; in addition to the attribute obtained by the reflection type determination unit, A recording material discriminating apparatus for discriminating a type of the recording material based on an attribute obtained by a type judging means. Including image reading means for obtaining an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and using the image of the surface of the recording material obtained by the image reading means In the recording material discriminating apparatus for determining the type of the recording material based on the attribute obtained by the reflection type judging means, comprising a reflection type judging means for judging a predetermined attribute of the recording material,
A light irradiating means for irradiating the recording material with predetermined irradiation light is provided, and a member having diffusivity is disposed between the optical paths between the light irradiating means and the recording material, and the diffusible member has reflection characteristics. A transmission type determination means for determining the attribute different from the reflection type determination means of the recording material by using the transmitted light obtained by transmitting the recording material. And a recording material discriminating apparatus for discriminating the type of the recording material based on the attribute obtained by the transmission type judging means in addition to the attribute obtained by the reflection type judging means. In order to obtain reflected light reflected from the surface of the recording material, reflection type irradiating means for irradiating the recording material with predetermined light, and the reflected light or transmitted light from the recording material is received and read as an image and the amount of light is detected. Read means and the reflection type irradiation means irradiate the recording material with light, cause the reading means to read the reflected light obtained by the reflection type irradiation means as an image, and based on the image, the type of the recording material In a recording material discriminating apparatus provided with a control means for discriminating
A light irradiating means for irradiating the recording material with a predetermined irradiation light; a member having diffusivity between the light irradiating means and the recording material; and a member having a reflection characteristic. In contrast, it has a configuration in which the diffusion performance and the direction of light are changed, and the transmission light obtained by transmitting the recording material is used to determine an attribute different from that of the reflection type determination means of the recording material. A recording material discriminating apparatus comprising: a type determining unit, wherein the type of the recording material is determined based on the attribute obtained by the transmission type determining unit in addition to the attribute obtained by the reflective type determining unit .   5. The recording material discriminating apparatus according to claim 1, wherein the diffusive member is configured at a position having a predetermined spatial distance with respect to the recording material. A latent image carrier for carrying a latent image, a developing means for visualizing the latent image as a developer image by applying a developer to the latent image carrier, and a developing means for recording material conveyed in a predetermined direction A transfer unit that transfers the developer image according to the method, and the recording material onto which the developer image has been transferred by the transfer unit is heated and pressed under predetermined fixing processing conditions to fix the developer image on the recording material. A fixing unit; and a video reading unit that obtains an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and the recording material surface obtained by the video reading unit Reflection type determination means for determining a predetermined attribute of the recording material using the image of the recording material, and determining the type of the recording material based on the attribute obtained by the reflection type determination means, and to the determined type The corresponding definition In the image forming apparatus to be fixed on the recording material the toner image by the processing conditions,
The fixing process conditions in the fixing means have a function of changing a heating temperature condition or a pressure condition or a recording material processing speed when fixing the recording material, and a predetermined irradiation light is applied to the recording material. A light irradiating means for irradiating, disposing a diffusive member between the light path between the light irradiating means and the recording material, and using the transmitted light obtained by transmitting the recording material, the reflection of the recording material A transmissive type determining means for determining an attribute different from the type determining means, wherein the fixing means is based on the attribute obtained by the transmissive type determining means in addition to the attribute obtained by the reflective type determining means; An image forming apparatus characterized by discriminating a type of a recording material and selectively applying the fixing processing condition corresponding to the discriminated type to fix the developer image on the recording material. A latent image carrier for carrying a latent image, a developing means for visualizing the latent image as a developer image by applying a developer to the latent image carrier, and a developing means for recording material conveyed in a predetermined direction A transfer unit that transfers the developer image according to the method, and the recording material onto which the developer image has been transferred by the transfer unit is heated and pressed under predetermined fixing processing conditions to fix the developer image on the recording material. A fixing unit; and a video reading unit that obtains an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and the recording material surface obtained by the video reading unit Reflection type determination means for determining a predetermined attribute of the recording material using the image of the recording material, and determining the type of the recording material based on the attribute obtained by the reflection type determination means, and to the determined type The corresponding definition In the image forming apparatus to be fixed on the recording material the toner image by the processing conditions,
The fixing process conditions in the fixing means have a function of changing a heating temperature condition or a pressure condition or a recording material processing speed when fixing the recording material, and a predetermined irradiation light is applied to the recording material. Uses light transmitted through the recording material using a light source that includes a light irradiating unit that irradiates and uses a light source with low directivity for the light irradiating unit or a milky white resin lens with high diffusibility. In addition to the attribute obtained by the reflection type determination unit, the fixing unit obtains the transmission type determination unit for determining an attribute different from the reflection type determination unit of the recording material. An image forming apparatus characterized by discriminating a type of the recording material based on a given attribute and selectively applying the fixing processing condition corresponding to the discriminated type to fix the developer image on the recording material. . A latent image carrier for carrying a latent image, a developing means for visualizing the latent image as a developer image by applying a developer to the latent image carrier, and a developing means for recording material conveyed in a predetermined direction A transfer unit that transfers the developer image according to the method, and the recording material onto which the developer image has been transferred by the transfer unit is heated and pressed under predetermined fixing processing conditions to fix the developer image on the recording material. A fixing unit; and a video reading unit that obtains an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and the recording material surface obtained by the video reading unit Reflection type determination means for determining a predetermined attribute of the recording material using the image of the recording material, determining the type of the recording material based on the attribute obtained by the reflection type determination means, and the determined type Corresponding to the above In the image forming apparatus to be fixed on the recording material the toner image by coating treatment conditions,
The fixing process conditions in the fixing unit have a function of changing a heating temperature condition or a pressurizing condition or a recording material processing speed when fixing the recording material, and irradiating the recording material with predetermined irradiation light. A diffusing member is arranged between the light irradiating means and the recording material, and the diffusing member has reflection characteristics and changes the direction of light from the irradiating means. A transmission type determination unit that determines a different attribute from the reflection type determination unit of the recording material using transmitted light that is transmitted through the recording material, and the fixing unit includes the reflection type In addition to the attribute obtained by the judging means, the type of the recording material is discriminated based on the attribute obtained by the transmission type judging means, and the fixing processing condition corresponding to the discriminated type is selectively applied. The developer image is fixed on the recording material. Image forming apparatus, characterized in that to. A latent image carrier for carrying a latent image, a developing means for visualizing the latent image as a developer image by applying a developer to the latent image carrier, and a developing means for recording material conveyed in a predetermined direction A transfer unit that transfers the developer image according to the method, and the recording material onto which the developer image has been transferred by the transfer unit is heated and pressed under predetermined fixing processing conditions to fix the developer image on the recording material. A fixing unit; and a video reading unit that obtains an image of the surface of the recording material by irradiating the recording material with light and reading reflected light reflected from the surface of the recording material, and the recording material surface obtained by the video reading unit Reflection type determination means for determining a predetermined attribute of the recording material using the image of the recording material, determining the type of the recording material based on the attribute obtained by the reflection type determination means, and the determined type Corresponding to the above In the image forming apparatus to be fixed on the recording material the toner image by coating treatment conditions,
The fixing process conditions in the fixing unit have a function of changing a heating temperature condition or a pressurizing condition or a recording material processing speed when fixing the recording material, and irradiating the recording material with predetermined irradiation light. A light irradiating means, a member having diffusivity between the light irradiating means and the recording material, a member having a reflection characteristic, and a diffusing performance and a direction of light with respect to the light from the irradiating means. And a transmission type determination unit for determining an attribute different from the reflection type determination unit of the recording material using transmitted light obtained by transmitting the recording material. In addition to the attribute obtained by the reflection type determination means, the type of the recording material is determined based on the attribute obtained by the transmission type determination means, and the fixing processing condition corresponding to the determined type is determined. Select and apply the current Image forming apparatus characterized by fixing the agent image to the recording material.   The image forming apparatus according to claim 6, wherein the diffusive member is configured at a position having a predetermined spatial distance with respect to the recording material.

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