Identification device and image forming apparatus equipped with identification device

Abstract

To provide a paper type identification device for identifying the type of a sheet with high accuracy.SOLUTION: A paper type identification device 100 comprises: a surface nature measuring unit 103 that measures, from a sheet to be conveyed, the surface nature of the sheet; and an information processing unit 160 that acquires a result of measurement performed by the surface nature measuring unit 103, and acquires a parameter for identifying the type of the sheet based on the measurement result. The information processing unit 160 determines whether the sheet is moving when the surface nature measuring unit 103 measures the sheet, when determining that the sheet is moving, acquires the parameter, and when determining that the sheet is not moving, discards the measurement result.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a paper type discrimination device capable of discriminating the type of a sheet and an image forming apparatus provided with such a paper type discrimination device.

Background Art

[0002] Electrophotographic image forming apparatuses such as copiers, printers, facsimiles, and multifunction peripherals form an image on a sheet conveyed through a conveyance path by each process of charging, exposure, development, transfer, and fixing. There are various types of sheets that can be used for image formation. The sheets have different characteristics (physical properties) such as paper thickness, smoothness, basis weight, and surface property depending on the type. The optimal operating conditions in each process of image formation vary depending on the physical properties (stiffness, basis weight, surface property, etc.) of the sheet used. Therefore, the image forming apparatus needs to change the operating conditions such as adjustment values for each process based on the type of the sheet. When a user uses the image forming apparatus, the user registers in advance the type of the sheet to be used. However, if an incorrect type is set, the image forming apparatus cannot form an image under appropriate operating conditions. In this case, a normal image cannot be formed on the sheet. For example, an abnormality occurs in the image formed on the sheet due to the occurrence of jamming, poor fixing, poor image density, or the like.

[0003] Patent Document 1 discloses an image forming apparatus that specifies the type of a sheet by a measuring instrument (media sensor) that measures the feature amount of the sheet and performs image formation. The measuring instrument notifies the image forming apparatus of the measurement result of the sheet. The image forming apparatus detects a paper profile that matches the measurement result from a plurality of pre-registered paper profiles and displays it on a display unit. Thereby, incorrect setting of the type of the sheet is reduced.

Prior Art Documents

Patent Documents

[0004] [[ID=2-6]]

Patent Document 1

Summary of the Invention

[0005] The sheets have uneven features, such as surface properties, and variations exist depending on the location on the sheet surface. Therefore, measuring a single point on the sheet results in low accuracy in identifying the sheet type. To measure as wide an area of ​​the sheet surface as possible using multiple points, the measuring instrument needs to measure features from a moving sheet. When measuring sheets that are manually inserted by a person, there is a possibility that the sheet may remain stationary for the entire measurement period or a certain period. In this case, multi-point measurement is not performed, and identification accuracy is not improved.

[0006] In view of the above-mentioned problems, the primary objective of the present invention is to provide a paper type identification device for highly accurate identification of sheet types. [Means for solving the problem]

[0007] The identification device of the present invention is an identification device in which, in the insertion direction in which a sheet is inserted, one end is an opening into which the sheet is inserted, and the other end is a stopper portion against which the sheet abuts, and the surface of the sheet One line at a time, multiple times in a row A reading sensor that reads, A determination means for determining whether the sheet inserted through the opening is moving based on the reading results of each pixel adjacent to the lines, obtained from the reading results of the reading sensor for each line, The device comprises a display means, and is characterized in that when the surface of the sheet is read by the reading sensor while the sheet inserted through the opening is not moving, a message indicating that the reading result is not normal is displayed on the display means. The present invention provides an image forming apparatus comprising: a component for forming an image on a sheet; an identification device for identifying the type of sheet; and a control means for setting the operating conditions of the component based on the type of sheet identified by the identification device. The identification device is an identification device in which, in the insertion direction in which the sheet is inserted, one end is an opening into which the sheet is inserted, and the other end is a stopper against which the sheet abuts. The identification device comprises: a reading sensor for reading the surface of the sheet line by line multiple times in succession; a determination means for determining whether the sheet inserted through the opening is moving based on the reading results of each pixel adjacent between lines from the reading results of the reading sensor line by line; and a display means. The present invention provides an image forming apparatus comprising: a component for forming an image on a sheet; an identification device for identifying the type of sheet; and a control means for setting the operating conditions of the component based on the type of sheet identified by the identification device. [Effects of the Invention]

[0008] According to the present invention, the type of sheet can be identified with high accuracy. [Brief explanation of the drawing]

[0009] [Figure 1] Diagram showing the configuration of an image forming apparatus. [Figure 2] (a) and (b) are enlarged views of the fuser unit 201. [Figure 3] Diagram illustrating the control unit. [Figure 4] (a) and (b) are explanatory diagrams of a paper type identification device. [Figure 5] (a) and (b) are explanatory diagrams of a paper type identification device. [Figure 6] Explanatory diagram of a paper type identification device. [Figure 7] Explanatory diagram of a line sensor. [Figure 8] Explanatory diagram of a line adjacent pixel difference integration value. [Figure 9] (a) to (c) are characteristic diagrams of a line adjacent pixel difference integration value. [Figure 10] Flowchart showing parameter acquisition processing for identifying paper types. [Figure 11] Exemplary diagram of a selection screen for paper type identification processing. [Figure 12] Exemplary diagram of an instruction screen. [Figure 13] Explanatory diagram of the relationship between ultrasonic transmittance and basis weight. [Figure 14] Exemplary diagram of an instruction screen. [Figure 15] Flowchart showing paper type identification processing. [Figure 16] Explanatory diagram of surface property classification. [Figure 17] Exemplary diagram of a paper selection screen after paper type identification. [Figure 18] Exemplary diagram of a paper selection screen after paper type identification. [Figure 19] Exemplary diagram of a paper type database. [Figure 20] Exemplary diagram of a paper type database. [Figure 21] Flowchart showing parameter acquisition processing for identifying paper types. [Figure 22] Timing chart for parameter acquisition when identifying paper types.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of this invention will be exemplarily and detailedly described with reference to the drawings.

[0011] (Image forming apparatus) Figure 1 is a diagram showing the configuration of the image forming apparatus of this embodiment. The image forming apparatus 201 of this embodiment is a tandem-intermediate transfer type laser beam printer that utilizes an electrophotographic process. The image forming apparatus 201 forms and outputs full-color or monochrome images on a sheet P based on image data acquired from an external device such as a personal computer via a network, or image data acquired from an image reading device 300.

[0012] The image forming apparatus 201 has components for forming images inside the main body 201A, and an image reading device 300, an operation unit 502, and a paper type identification device 100 are provided on the upper part of the main body 201A. An discharge space S is formed between the main body 201A and the image reading device 300 of the image forming apparatus 201, through which the sheet P after image formation is discharged.

[0013] The image reading device 300 is a scanner that reads an image from a document and generates image data. The image reading device 300 is used during the document copying process. The operation unit 502 is a user interface equipped with an input interface and an output interface. The input interface is, for example, various key buttons, a touch panel, etc. The output interface is a display, a speaker, etc. The user can input various instructions to the image forming apparatus 201 using the operation unit 502. The paper type identification device 100 can identify the type of sheet P used for image formation (printing) by the image forming apparatus 201. Details of the paper type identification device 100 will be described later.

[0014] The image forming apparatus 201 includes an image forming unit 201B, an intermediate transfer unit 201C, a secondary transfer unit 201D, a fuser 201E, and a cassette paper feed unit 230 within the main body 201A.

[0015] The cassette paper feed unit 230 feeds sheets P from the paper feed cassette 1 which stores the sheets P. The cassette paper feed unit 230 includes a pickup roller 2 and a separation unit consisting of a feed roller 3 and a retard roller 4 for separating the sheets P fed out from the pickup roller 2. The sheets P are fed one by one from the paper feed cassette 1 by the pickup roller 2 and the separation unit. In this embodiment, a configuration in which multiple (four in this case) cassette paper feed units 230 are provided is described, but there may be any number of cassette paper feed units 230. The sheets P fed from the cassette paper feed unit 230 are transported along the transport path to the register roller pair 240.

[0016] In addition to the cassette paper feed unit 230, the sheets P can also be fed from the manual feed unit 235. The manual feed unit 235 is equipped with a manual feed tray 5 on which the user places the sheets. Similar to the cassette paper feed unit 230, the manual feed unit 235 is equipped with a pickup roller and a separation unit, and the sheets P are fed one by one from the manual feed tray 5. The sheets P fed from the manual feed unit 235 are also transported along the transport path to the register roller pair 240.

[0017] The image forming unit 201B is a 4-drum full-color system and comprises a laser scanner 210 and four process cartridges 211 that form toner images of four colors: yellow (Y), magenta (M), cyan (C), and black (K). Each process cartridge 211 includes a photosensitive drum 212, a charger 213, and a developer 214. A toner cartridge 215 is positioned above the process cartridges 211. The toner cartridge 215 supplies toner to the developer 214.

[0018] The intermediate transfer section 201C includes an intermediate transfer belt 216 wrapped around a drive roller 216a and a tension roller 216b. Inside the intermediate transfer belt 216 are four primary transfer rollers 219 that contact the intermediate transfer belt 216 at positions opposite each photosensitive drum 212. The intermediate transfer belt 216 rotates in the direction of the arrow by the drive roller 216a, which is driven by a drive unit (not shown).

[0019] The secondary transfer unit 201D includes a secondary transfer roller 217 positioned opposite the drive roller 216a, sandwiching the intermediate transfer belt 216. The fuser 201E is located downstream of the secondary transfer roller 217 in the sheet P transport direction and includes a pressure roller 220a and a heating roller 220b. Downstream of the fuser 201E in the sheet P transport direction, a first discharge roller pair 225a, a second discharge roller pair 225b, and a double-sided reversal unit 201F are arranged. The double-sided reversal unit 201F includes a reversible reversible roller pair 222 and a re-transport passage R for transporting the sheet P, on which an image has been formed on one side, back to the image forming unit 201B.

[0020] The image forming apparatus 201, configured as described above, operates as follows: The image forming apparatus 201 acquires image data from the image reading device 300 or an external device and forms an image on the sheet P corresponding to the image data. In this process, the image forming apparatus 201 performs each image forming step under operating conditions corresponding to the type of sheet P.

[0021] The image forming unit 201B uniformly charges the surface of the photosensitive drum 212 to a predetermined polarity using the charger 213. The laser scanner 210 irradiates the uniformly charged surface of the photosensitive drum 212 with laser light modulated based on the image data. As a result, an electrostatic latent image corresponding to the color (yellow, magenta, cyan, black) is formed on the surface of each photosensitive drum 212.

[0022] The image forming unit 201B develops the electrostatic latent image formed on the photosensitive drum 212 by the developer unit 214. On each photosensitive drum 212, the electrostatic latent image is developed with toner of the corresponding color, forming a toner image of the corresponding color. The toner images are sequentially transferred from the photosensitive drum 212 to the rotating intermediate transfer belt 216 by the primary transfer roller 219. This forms a full-color toner image on the intermediate transfer belt 216. The intermediate transfer belt 216 rotates to transport the toner image to the secondary transfer unit 201D.

[0023] In parallel with this toner image formation operation, the sheets P are transported one by one to the register roller pair 240 by the cassette paper feed unit 230 or the manual paper feed unit 235. The register roller pair 240 corrects the skewness of the transported sheets P. After the skewness is corrected, the sheets P are transported by the register roller pair 240 to the secondary transfer unit 201D at the same time that the toner image carried by the intermediate transfer belt 216 is transported to the secondary transfer unit 201D. The secondary transfer unit 201D transfers the full-color toner image from the intermediate transfer belt 216 onto the sheets P using a secondary transfer bias applied to the secondary transfer roller 217.

[0024] The sheet P onto which the toner image has been transferred is transported to the fuser unit 201E. The fuser unit 201E grips and transports the sheet P using a roller nip section formed by a pressure roller 220a and a heating roller 220b. When gripping and transporting the sheet P, the fuser unit 201E heats the sheet P with the heating roller 220b, melting and mixing the toners of each color on the sheet P. The fuser unit 201E also pressurizes the sheet P with the pressure roller 220a, fixing the melted and mixed toners to the sheet P. At this time, the adhesive force of the melted toner generates a force that causes the sheet P to stick to the heating roller 220b.

[0025] Figure 2 is an enlarged view of the fuser unit 201E. If the rigidity (stiffness) of the sheet P is weak, the adhesive force generated on the sheet P against the heating roller 220b may cause the sheet P to be wound up by the rotating heating roller 220b (Figure 2(b)). For this reason, a separation plate 202 for separating the sheet P is provided downstream of the heating roller 220b in the direction of sheet P transport (Figure 2(a)).

[0026] The image forming apparatus 201 may determine the state of the separation plate 202 according to the type of sheet P. For example, when forming an image on a sheet P of low rigidity, the separation plate 202 is positioned so that its tip contacts the surface of the heating roller 220b, as shown in Figure 2(a), to separate the sheet P from the heating roller 220b. When forming an image on a sheet P of high rigidity, the sheet P is not wound onto the heating roller 220b. For this reason, the separation plate 202 is positioned so that its tip does not contact the surface of the heating roller 220b. This prevents the surface of the heating roller 220b from being worn down by the separation plate 202.

[0027] The sheet P on which the image has been fixed is discharged into the discharge space S by either the first discharge roller pair 225a or the second discharge roller pair 225b. The sheet P is then loaded onto the loading section 223, which is provided protruding from the bottom surface of the discharge space S. When forming an image on both sides of the sheet P, after the image has been fixed to one side, the sheet P is transported to the re-transport passage R by the reversing roller pair 222, and then transported again to the image forming section 201B, where an image is formed on the reversed side.

[0028] (Control Unit) Figure 3 is an explanatory diagram of the control unit that controls the operation of such an image forming apparatus 201. The control unit 400 is an information processing device equipped with, for example, a CPU (Central Processing Unit). The control unit 400 may also be implemented using an MPU (Micro Processor Unit) or an ASIC (Application Specific Integrated Circuit). The control unit 400 controls the image forming process performed by the image forming apparatus 201. In this embodiment, the control unit 400 is connected to the paper type identification device 100 and controls the paper type identification device 100. The control unit 400 is connected to a memory 401 and an operation unit 502. The memory 401 includes a paper type database 402. The paper type database 402 stores information such as the physical properties of various types of sheets, parameters for the operating conditions of each component during optimal image forming, whether paper can be fed into the image forming apparatus 201, and usable paper feed slots.

[0029] The paper type identification device 100 includes an information processing unit 160. The information processing unit 160 is an information processing device implemented by, for example, a CPU, MPU, or ASIC. The information processing unit 160 is communicatively connected to the control unit 400 and can operate in cooperation with the control unit 400. An upstream sheet sensor 104, a downstream sheet sensor 105, a mechanical property measurement unit 102, and a surface property measurement unit 103 are connected to the information processing unit 160. The mechanical property measurement unit 102 includes an ultrasonic sensor 120 and a paper thickness sensor 140. The surface property measurement unit 103 includes an optical sensor 150. The information processing unit 160 controls the operation of the upstream sheet sensor 104, the downstream sheet sensor 105, the mechanical property measurement unit 102, and the surface property measurement unit 103, and acquires the measurement results of each.

[0030] The upstream sheet sensor 104 is a sensor that detects the insertion of sheet P into the paper type identification device 100. When the upstream sheet sensor 104 detects sheet P, the information processing unit 160 starts the measurement sequence for the feature quantities of sheet P. The downstream sheet sensor 105 is a sensor that detects when sheet P has reached the innermost part of the paper type identification device 100 into which sheet P can be inserted (the stopper part described later). The ultrasonic sensor 120 is a sensor used to measure the basis weight of sheet P. The paper thickness sensor 140 is a sensor used to measure the paper thickness of sheet P. The optical sensor 150 is a sensor used to measure the adjacent pixel difference integrated value and surface information such as brightness of sheet P. The adjacent pixel difference integrated value is the value obtained by accumulating the difference between the detected values ​​(measurement results) for each adjacent pixel in the measurement direction of one line by the optical sensor 150. The optical sensor 150 outputs the brightness value for each pixel as the measurement result. The information processing unit 160 stores the measurement results and generates surface property information based on the measurement results. Details of the ultrasonic sensor 120, paper thickness sensor 140, and optical sensor 150 will be described later.

[0031] The information processing unit 160 transmits the mechanical property information (basis weight and paper thickness) acquired by the mechanical property measurement unit 102 and the surface property information acquired by the surface property measurement unit 103 to the control unit 400. The control unit 400 determines the paper type of sheet P based on the acquired surface property information. Subsequently, the control unit 400 identifies the brand name of sheet P based on the paper type and mechanical property information (basis weight and paper thickness) using the paper type database 402 and displays it on the display of the operation unit 502.

[0032] (Types of sheets used in image forming apparatus) The operating conditions of each component in each step of the image formation process (such as transport speed during fixing, fixing temperature, and transfer voltage during secondary transfer) vary depending on the physical properties of the sheet P on which the image is formed, including its basis weight, stiffness, surface properties, and material. Therefore, it is important to know in advance what type of sheet P will be used during image formation.

[0033] There may be restrictions on how sheets P can be loaded into the paper feed slot. The paper feed slots are paper cassette 1 and manual feed tray 5. For example, some thick paper with high rigidity can only be fed from manual feed tray 5, which has a small curvature in the transport path. Coated paper, which has a smooth surface and strong adhesion between sheets, must be fed one sheet at a time from manual feed tray 5. Paper made from pulp generally has different bending rigidity depending on the direction of the paper, due to the bias in the orientation direction (grain direction) of the pulp fibers that occurs due to the manufacturing process. For this reason, some pulp-based papers have recommended orientations for loading into the paper feed slot to reduce bending rigidity in the transport path. In addition, single-sided coated paper, which is coated on only one side compared to plain paper, has a specified up and down orientation when loading in order to form an image on the coated surface.

[0034] Some sheets cannot be used with the image forming apparatus 201. For example, thick paper with excessive stiffness may cause the paper to stop being transported due to the resistance when it is transported along the curved transport path. Thin paper with excessive stiffness is strongly affected by the adhesive force between the molten toner and the heating roller 220b as it passes through the fuser unit 201E, as described above. As a result, paper with excessive stiffness may not be peeled off the heating roller 220b by the separation plate 202 and may become wrapped around it (Figure 2(b)). In addition, synthetic paper made from synthetic resin instead of pulp may melt when heated in the fuser unit 201E, potentially contaminating the heating roller 220b.

[0035] (Paper type identification device) Figures 4, 5, and 6 are explanatory diagrams of the paper type identification device 100. Figure 4 shows the state before sheet P is inserted into the paper type identification device 100. Figure 5 shows the state after sheet P has been inserted into the paper type identification device 100. Figures 4(a) and 5(a) are views of the paper type identification device 100 from the side (the front direction of the image forming apparatus 201 in Figure 1). Figures 4(b) and 5(b) are views of the paper type identification device 100 from above. Figure 6 is a view of the paper type identification device 100 from the direction in which sheet P is inserted.

[0036] The paper type identification device 100 has a groove 101 into which the sheet P to be identified is inserted, and measures the physical properties of the sheet P inserted from the groove 101. The insertion of the sheet P is performed manually by the user. The groove 101 has an upper block 109 at the top and a lower block 110 at the bottom.

[0037] A sheet retaining member 106 is provided at the back of the groove in the lower block 110. The sheet retaining member 106 is biased toward the upper block 109 by a biasing member 107. The sheet P is inserted by pushing the sheet retaining member 106 downwards. The upper block 109 protrudes toward the lower block 110 at the end of the sheet retaining member 106 (the innermost part into which the sheet P can be inserted), forming a stopper portion 108. Because the stopper portion 108 restricts the insertion of the inserted sheet P, the sheet P can be inserted up to the stopper portion 108. An information processing unit 160 is located behind the stopper portion 108.

[0038] The unit for measuring the physical properties of sheet P consists of a mechanical property measuring unit 102 and a surface property measuring unit 103, as described above. As sheet P passes through the measuring unit, physical properties such as basis weight, surface properties, and paper thickness of sheet P are acquired. An upstream sheet sensor 104 is positioned upstream of the surface property measuring unit 103 in the insertion direction of sheet P. A downstream sheet sensor 105 is positioned near the upstream side of the abutment unit 108 in the insertion direction of sheet P. In other words, the upstream sheet sensor 104 is positioned at the insertion start position of sheet P, and the downstream sheet sensor 105 is positioned at the insertion end position of sheet P. The upstream sheet sensor 104 and the downstream sheet sensor 105 each detect the inserted sheet P.

[0039] As shown in Figure 6, the mechanical property measurement unit 102 is configured such that the ultrasonic oscillator 130 is on the lower block 110 side and the ultrasonic receiver 131 is on the upper block 109 side, flanking the insertion path through which the sheet P is inserted. The ultrasonic oscillator 130 and ultrasonic receiver 131 constitute an ultrasonic sensor 120. The mechanical property measurement unit 102 can detect the basis weight of the sheet P by transmitting and receiving ultrasonic waves through the insertion path of the sheet P using the ultrasonic sensor 120. Basis weight is the mass per unit area of ​​the sheet P and is expressed in units of [gsm].

[0040] Both the ultrasonic oscillator 130 and the ultrasonic receiver 131 consist of a piezoelectric element (also called a piezo element), which is an element that converts mechanical displacement and electrical signals, and electrode terminals. When a pulse voltage of a predetermined frequency is input to the electrode terminals of the ultrasonic oscillator 130, the piezoelectric element oscillates and generates ultrasonic waves. The generated ultrasonic waves propagate through the air. When the ultrasonic waves reach the sheet P, the sheet P vibrates due to the ultrasonic waves. The ultrasonic waves generated by the ultrasonic oscillator 130 propagate through the sheet P to the ultrasonic receiver 131. The piezoelectric element of the ultrasonic receiver 131 generates an output voltage at its electrode terminals corresponding to the amplitude of the received ultrasonic waves. The output voltage is a voltage value corresponding to the basis weight of the sheet P. The output voltage is transmitted to the information processing unit 160 as a measured value.

[0041] Compared to the case where there is no sheet P between the ultrasonic oscillator 130 and the ultrasonic receiver 131, the output voltage due to the ultrasound transmitted through the sheet P is attenuated. The information processing unit 160 calculates the transmittance of sheet P based on the ratio of the output voltage with and without sheet P. Since the transmittance of ultrasound changes depending on the thickness of sheet P, the information processing unit 160 can estimate the basis weight of sheet P using the ultrasonic transmission coefficient-basis weight conversion formula. In this way, the basis weight of sheet P is detected using the ultrasonic sensor 120.

[0042] An upstream sheet sensor 104, located on the upper block 109 upstream of the surface quality measurement unit 103 in the insertion direction of sheet P, detects the insertion of sheet P into the paper type identification device 100. A downstream sheet sensor 105, located on the upper block 109 downstream of the surface quality measurement unit 103 in the insertion direction of sheet P, detects the arrival of sheet P at the abutment unit 108, which the fully inserted sheet P will abut against.

[0043] The paper thickness sensor 140 is positioned near the abutment portion 108. The paper thickness sensor 140 is lever-type, and as the lever tilts according to the thickness of the sheet P, an encoder linked to the lever rotates according to the amount it has tilted. While the encoder is rotating, the paper thickness sensor 140 transmits a pulse signal as a measured value of the paper thickness to the information processing unit 160. The paper thickness sensor 140 is positioned slightly downstream of the downstream sheet sensor 105 in the insertion direction of the sheet P, so that the paper thickness can be measured when the downstream sheet sensor 105 detects the sheet P.

[0044] As described above, the surface quality measurement unit 103 includes an optical sensor 150 for detecting the surface quality of the sheet P. The optical sensor 150 comprises a light-emitting unit 132 and a line sensor 133. The optical sensor 150 is, for example, a CIS (Contact Image Sensor). The light-emitting unit 132 is, for example, an LED (Light Emitted Diode). The line sensor 133 is composed of multiple light-receiving elements arranged in a row. For example, the line sensor 133 may be a CMOS line sensor equipped with a CMOS sensor as a light-receiving element.

[0045] As shown in Figure 6, the surface measurement unit 103 (optical sensor 150) is equipped with a light-emitting unit 132 and a line sensor 133 on the upper block 109 side. The line sensor 133 has multiple light-receiving elements arranged in a direction perpendicular to the insertion direction of the sheet P of the paper type identification device 100. For this reason, the line sensor 133 detects the surface of the sheet P by considering the direction intersecting the insertion direction of the sheet P as one line. The line sensor 133 is capable of detecting the paper surface area with a resolution corresponding to the pixel size and the imaging magnification of the optical system.

[0046] The amount of light reflected from the sheet P to the line sensor 133 varies depending on the surface properties of the sheet P. For example, glossy paper has a smoother surface (less unevenness) than plain paper. Therefore, glossy paper has a larger amount of specularly reflected light and a smaller amount of diffusely reflected light compared to plain paper. In other words, the amount of reflected light essentially indicates the smoothness of the sheet P's surface. By using the amount of specularly reflected light, diffusely reflected light, or both, from the sheet P incident on the line sensor 133, the type of sheet P can be determined.

[0047] The line sensor 133 is configured to sample reflected light based on a clock signal with a predetermined sampling frequency. In this embodiment, the surface quality measurement method for sheet P using the surface quality measurement unit 103 uses the results of multiple samplings. Details will be described later.

[0048] The surface quality measuring unit 103 needs to hold the sheet P at the optical focal position. To this end, the biasing member 107 biases the sheet P toward the surface quality measuring unit 103, and the sheet holding member 106 stabilizes the orientation of the sheet P. This reduces variations in the position and orientation of the sheet P when detecting its surface, allowing the surface quality measuring unit 103 to reliably detect the surface quality. The biasing member 107 is set to press the inserted sheet P toward the surface quality measuring unit 103 with a force of approximately 100 gf.

[0049] Figure 7 is an explanatory diagram of the line sensor 133. The line sensor 133 can detect n pixels of an image at once in a direction perpendicular to the insertion direction of the sheet P. To this end, the photodetectors are arranged in series, for example, n in a direction perpendicular to the insertion direction of the sheet P. In this embodiment, the photodetectors of the line sensor 133 are arranged to detect an image with a resolution of 300 [dpi].

[0050] The optical sensor 150 detects one line of image at a time. In this case, the optical sensor 150 only detects local irregularities on the surface of the sheet P. If the surface properties of the sheet P are judged based on the detection result of one line, the deviation of the detection result for each measurement position will be large. For this reason, it is difficult to determine the surface properties based on the detection result of one line. In other words, the reading result (detection result) of one line of image is insufficient to identify the surface properties of the sheet P.

[0051] In this embodiment, the optical sensor 150 performs a line reading operation multiple times in succession in the insertion direction of the sheet P. The information processing unit 160 combines the detection results for each line in the insertion direction to generate a detection result for the entire surface of the sheet P, thereby understanding the surface properties trend of the sheet P. To this end, the optical sensor 150 performs measurements dynamically while the sheet P is moving relative to it.

[0052] (superficial information) The information processing unit 160 performs digital processing on the image detected by the optical sensor 150 and obtains the detected value (luminance value) for each pixel. The detected value (luminance value) is stored in the memory inside the information processing unit 160. Based on the detected value stored in the memory, the information processing unit 160 obtains the adjacent pixel difference integrated value and brightness as surface information. The information processing unit 160 stores the surface information in the memory.

[0053] As described above, the adjacent pixel difference integrated value is the value obtained by accumulating the differences in detected values ​​(luminance values) of adjacent pixels in the direction of one line, and serves as an indicator of the surface irregularities of sheet P. If the detected values ​​of each pixel (result of one sampling) in Figure 7 are denoted as "A1" to "An" according to the pixel position, the adjacent pixel difference integrated value k is expressed by the following formula. k=(A2-A1)+(A3-A2)…+(An-A(n-1))

[0054] Brightness is the integrated value of the detection values ​​of each pixel of the optical sensor 150, and is a parameter that correlates with the reflectance (brightness) of the sheet P. For example, transparent films made of resin such as PET are measured as having low brightness because they reflect little light. Sheet P with a geometric uneven surface, such as embossed paper, has a large difference in brightness between adjacent pixels due to the unevenness, resulting in a large integrated value of adjacent pixel differences. Recycled paper tends to be measured as having a rough surface because the grain direction is uneven and the pulp fibers become shorter after going through several recycling processes. Coated paper appears to have less unevenness due to the coating layer on the surface, and tends to have a small integrated value of adjacent pixel differences. In this way, the surface properties of the sheet P can be classified from the detection values ​​of the optical sensor 150, and the sheet can be classified according to the sheet category used in the image forming apparatus 201.

[0055] (Determining the movement status of sheet P) In this embodiment, in order to determine whether the sheet P is moving during measurement by the surface quality measurement unit 103, the integrated difference value of adjacent line pixels is used as surface quality information. Figure 8 is an explanatory diagram of the integrated difference value of adjacent line pixels.

[0056] The integrated line-adjacent pixel difference value is the sum of the differences in detected values ​​(luminance values) for each pixel adjacent to a line. As shown in Figure 8, if the detected value for the first line is A, the detected value for the second line is B, the detected value for the third line is C, and so on, the integrated line-adjacent pixel difference value h is expressed by the following formula. The integrated line-adjacent pixel difference value is calculated for each pixel in the direction of one line in Figure 8. h1=(A1-B1)+(A2-B2)+…+(An-Bn) h2=(B1-C1)+(B2-C2)+…+(Bn-Cn)

[0057] The integrated line-adjacent pixel difference value is calculated by comparing the detected values ​​(luminance values) of the same pixel (same position in the measurement line direction) for each line. Therefore, if the detection position of sheet P is the same in the first and second lines, that is, when sheet P is not being transported, the luminance values ​​of each pixel in the first and second lines are the same. As a result, the value of the integrated line-adjacent pixel difference value h1 will be approximately "0".

[0058] Figure 9 is a characteristic diagram of the integrated difference value of adjacent pixels when n lines are measured. The horizontal axis represents the pixels (h1 to hn-1) for which the integrated difference value of adjacent pixels is calculated, and the vertical axis represents the integrated difference value of adjacent pixels. The threshold m is predetermined and is a value used to determine whether detection was performed in the same position and transport state, for example, the maximum value of the integrated difference value of adjacent pixels when the same detection position (pixel) is measured.

[0059] Figure 9(a) shows the integrated line-adjacent pixel difference value when sheet P is moving during surface quality measurement. In this case, the integrated line-adjacent pixel difference value h is greater than the threshold m. Figure 9(b) shows the integrated line-adjacent pixel difference value when sheet P stops moving midway through surface quality measurement. In this case, the integrated line-adjacent pixel difference value h, based on the detected value when sheet P has stopped moving, is less than the threshold m. Figure 9(c) shows the integrated line-adjacent pixel difference value when sheet P is not moving during surface quality measurement. In this case, the integrated line-adjacent pixel difference value h is less than the threshold m. In this way, the movement state of sheet P is determined by comparing the integrated line-adjacent pixel difference value with the threshold m.

[0060] (Paper type identification) Figure 10 is a flowchart showing the parameter acquisition process for identifying the paper type of sheet P. Here, the number of lines to be measured is set to 600 lines. Figure 11 is an example of the selection screen for the paper type identification process of sheet P. The selection screen is displayed on the display of the operation unit 502. The selection screen includes a "Manual Sheet Selection" button for the user to manually input the type of sheet P, and a "Automatic Sheet Identification" button for the paper type identification device 100 to automatically select the type of sheet P. In this embodiment, the user selects the "Automatic Sheet Identification" button from the selection screen using the operation unit 502, and the selection is input to the control unit 400.

[0061] When the control unit 400 receives information from the operation unit 502 indicating that the "Automatic Sheet Identification" button has been selected, it sets the operation mode to the automatic sheet identification mode for sheet P (S1). Once set to automatic identification mode, the control unit 400 notifies the information processing unit 160 of the paper type identification device 100 that it has switched to the automatic sheet identification mode for sheet P by instructing it to measure sheet P (S2).

[0062] The information processing unit 160 performs initialization processing on the mechanical property measurement unit 102 and the surface property measurement unit 103 in preparation for inserting the sheet P (S3). After the information processing unit 160 has performed the initialization processing, the control unit 400 displays an instruction screen on the display of the operation unit 502 instructing the user to insert the sheet P. Figure 12 is an example of the instruction screen displayed on the display of the operation unit 502 instructing the user to insert the sheet P. The user starts inserting the sheet P into the groove 101 of the paper type identification device 100 according to the instruction screen (S4).

[0063] When the sheet P is inserted into the groove 101, the information processing unit 160 waits until the upstream sheet sensor 104 detects the sheet P (S5:N). When the upstream sheet sensor 104 detects the sheet P (S5:Y), the information processing unit 160 uses this as a trigger (t=0) and, after a predetermined time t1 has elapsed, starts measuring the surface properties of the sheet P using the surface property measurement unit 103 (optical sensor 150) (S6). The information processing unit 160 causes the optical sensor 150 to read the sheet P and acquires the reading results (detected values) sequentially. The optical sensor 150 measures the surface properties of the sheet P by scanning the transported sheet P multiple times at predetermined time intervals. The information processing unit 160 performs the above processing on the reading results (detected values) from the optical sensor 150 to generate surface property information and stores it in the internal memory.

[0064] The information processing unit 160 starts measuring the physical properties of sheet P using the mechanical property measurement unit 102 after a predetermined time t2 (t2 > t1) has elapsed since the upstream sheet sensor 104 detected sheet P (S7). The information processing unit 160 measures the ultrasonic transmittance of sheet P using the ultrasonic sensor 120, converts the measured value into basis weight information, and stores the basis weight information in memory. Figure 13 is an explanatory diagram of the relationship between ultrasonic transmittance and basis weight. The information processing unit 160 maintains a conversion formula or conversion table that shows the relationship between ultrasonic transmittance and basis weight. The information processing unit 160 converts the measured value into basis weight using such a conversion formula or conversion table. In this way, the basis weight information of sheet P is stored in the memory of the information processing unit 160 by measuring the physical properties. The information processing unit 160 also waits for the count of the pulse signal output from the paper thickness sensor 140, triggered by the detection of sheet P by the upstream sheet sensor 104.

[0065] The information processing unit 160 waits until the downstream sheet sensor 105 detects sheet P (S8:N). The downstream sheet sensor 105 detects sheet P when it has been inserted to the innermost abutment portion 108. When the downstream sheet sensor 105 detects sheet P (S8:Y), the information processing unit 160 acquires a pulse signal, which is a measured value, from the paper thickness sensor 140. The information processing unit 160 measures the paper thickness of sheet P based on the number of pulse signals acquired (number of pulses) (S9). The paper thickness of sheet P is stored in the memory of the information processing unit 160. Also, when the downstream sheet sensor 105 detects sheet P, the information processing unit 160 stops reading sheet P by the optical sensor 150 of the surface quality measurement unit 103.

[0066] The information processing unit 160 compares all line-adjacent pixel difference integrated values ​​h1 to h599 stored in memory as surface properties information with a threshold m (S10). If at least one line-adjacent pixel difference integrated value h1 to h599 is smaller than the threshold m (S10:N), the information processing unit 160 determines that the sheet P has not moved (was not transported) during measurement by the surface properties measurement unit 103. In this case, the information processing unit 160 determines that the surface properties information of the sheet P has not been accurately acquired. The information processing unit 160 discards all information stored in memory and sends error information to the control unit 400 of the image forming apparatus 201 (S11). When the control unit 400 receives the error information, it displays an instruction screen on the display of the operation unit 502 instructing the reinsertion of the sheet P. Figure 14 is an example of the instruction screen instructing the reinsertion of the sheet P. The information processing unit 160, having sent the error information, will repeat the processing from S4 onwards.

[0067] If all line-adjacent pixel difference integrated values ​​h1 to h599 are greater than the threshold m (S10:Y), the information processing unit 160 determines that the sheet P is moving (being transported) during measurement by the surface quality measurement unit 103. In this case, the information processing unit 160 determines that the measurement results have been accurately acquired. The information processing unit 160 transmits to the control unit 400 of the image forming apparatus 201 completion information indicating that the process has been completed successfully, along with parameters such as basis weight, surface quality information, and paper thickness stored in memory (S12). These parameters are information for identifying the type of sheet P.

[0068] The control unit 400 identifies the type of sheet P based on parameters obtained from the information processing unit 160. Figure 15 is a flowchart representing the paper type identification process.

[0069] The control unit 400 classifies the type of sheet P based on the measurement results of the surface properties of sheet P (S21). Figure 16 is an explanatory diagram of the surface property classification. In Figure 16, a matrix is ​​used as an index of surface properties, with the vertical axis representing the integrated difference value of adjacent pixels and the horizontal axis representing brightness, and the surface properties of sheet P are measured and classified in advance. The control unit 400 refers to the matrix according to the surface property information (integrated difference value of adjacent pixels and brightness) obtained from the detected values ​​detected by the optical sensor 150 and classifies the type of sheet P.

[0070] The control unit 400 determines the type of sheet P by adding basis weight to the classification by surface properties (S22). By adding basis weight to the parameters for identifying the paper type, the control unit 400 can further classify and identify the sheet P. Furthermore, the control unit 400 improves the accuracy of estimation based on basis weight by using paper thickness (S23). Coated paper is made by coating the surface of medium-grade paper or the like with a coating made by mixing a white pigment such as clay (kaolin) or calcium carbonate with an adhesive (binder) such as starch. Because coated paper has a higher density than ordinary printing paper whose main component is pulp, the error in basis weight conversion using the ultrasonic transmission coefficient-basis weight conversion formula becomes larger. Therefore, by simultaneously using paper thickness as a parameter for identifying the paper type, the accuracy of sheet P identification is improved. In particular, adding paper thickness information is useful for identifying the brand of sheet P. The control unit 400 determines the paper type of sheet P based on these parameters (S24).

[0071] Figures 17 and 18 are illustrative diagrams of the paper selection screen after paper type identification. The paper selection screen is displayed on the display of the operation unit 502. The paper type determined in process S24 is displayed on the paper selection screen. The user can select the type of sheet P to be used for printing from the paper type determined in process S24 using the paper selection screen.

[0072] The paper selection screen in Figure 17 displays the types of sheet settings that can be selected for each sheet category pre-set in the image forming apparatus 201. Sheet P may be classified into a sheet category different from its nominal basis weight due to variations in basis weight, etc. Therefore, the paper selection screen also displays categories close to the detected sheet category. In addition, the word "Recommended" is displayed for the paper type determined in processing S24. The paper selection screen in Figure 18 allows the selection of the sheet brand. Sheet settings are made by specifying the sheet brand. The user assigns the sheet setting to the paper feed stage by selecting a sheet from these list of sheet categories and sheet brands using the operation unit 502. This ensures that the type of sheet P is accurately identified and printing under the correct operating conditions is possible.

[0073] Figures 19 and 20 are illustrative diagrams of the paper type database 402 stored in the memory 401 of the image forming apparatus 201. As described above, the paper type database 402 includes information such as the physical properties of various types of sheets, parameters for optimal operating conditions during image formation, whether paper can be fed into the image forming apparatus 201, and the usable paper feed slots. The paper type database 402 stores reference values ​​for surface properties and paper thickness measured by the paper type identification device 100, as shown in Figure 20, linked to the paper type information. The control unit 400 refers to these values, determines the candidate with the highest similarity, and displays the paper selection screen shown in Figures 17 and 18 on the display of the operation unit 502. This allows the user to easily set the sheet.

[0074] The sheet type is determined, which also determines the sheet classification. This allows the operating conditions of each component of the image forming apparatus 201 to be determined using the paper type database in Figure 19. As a result, the sheet settings are made accurately, and the image forming apparatus 201 can form an image on the sheet P with optimal quality.

[0075] As described above, the paper type identification device 100 of this embodiment determines whether the sheet P is moving (transporting) during surface quality measurement based on the integrated line adjacent pixel difference value calculated from the detected value by the optical sensor 150. If the sheet P is not moving, the information processing unit 160 determines that accurate detected values ​​have not been obtained, discards the acquired detected values, and notifies the user of the error and the need for remeasurement. Through this process, the paper type identification device 100 can improve the accuracy of the information (parameters) used to identify the type of sheet P. The image forming apparatus 201 using such parameters will have improved sheet P identification accuracy.

[0076] In this embodiment, the paper type identification device 100 is equipped with an information processing unit 160 that processes the measurement results from the mechanical property measurement unit 102 and the surface property measurement unit 103 and transmits them to the control unit 400 of the image forming apparatus 201. However, the processing of these measurement results may also be performed directly by the control unit 400. In this case, the functions of the information processing unit 160 would be included in the control unit 400. Alternatively, the paper type identification device 100 would transmit the measurement results from the mechanical property measurement unit 102 and the surface property measurement unit 103 directly to the control unit 400.

[0077] In this embodiment, the image forming apparatus 201 is equipped with the paper type database 402, but the paper type identification device 100 may be equipped with the paper type database 402. In this case, the information processing unit 160 of the paper type identification device 100 will perform the identification of the paper type of sheet P, which is performed by the control unit 400. Furthermore, although an example has been described in which sheet detection by the upstream sheet sensor 104 is used as the trigger, it is also possible to use sheet detection by the downstream sheet sensor 105 as the trigger. In this case, surface quality measurement is performed when sheet P is withdrawn from the paper type identification device 100. Instead of the downstream sheet sensor 105, the encoder rotation of the paper thickness sensor 140 may be detected, and the reading interval by the surface quality measurement unit 103 may be determined based on that timing.

[0078] The above describes an example in which the operating conditions (control parameters) of the image forming apparatus 201 are determined by selecting the sheet category and sheet brand from the features detected by the paper type identification device 100. The paper type identification device 100 may also be a paper physical property measuring device, and the control parameters may be determined directly from the measured sheet features. In addition, the paper type database 402 and the control unit 400 may be located on the cloud. In that case, if the image forming apparatus 201 is connected to the cloud via a network, the latest paper type setting information and identification algorithm can always be selected.

[0079] (modified version) The decision to move (transport) sheet P may be made based on the detection timing of sheet P by the upstream sheet sensor 104 and the downstream sheet sensor 105. Figure 21 is a flowchart showing the parameter acquisition process for identifying the paper type of sheet P in this case. The same steps as in the flowchart of Figure 10 are given the same step numbers. The explanation of the same processes is omitted. Figure 22 is a timing chart for acquiring parameters for identifying the paper type of sheet P.

[0080] When the user inserts a sheet P into the groove 101 of the paper type identification device 100, the upstream sheet sensor 104 detects the sheet P (S5:Y). The timing at which the upstream sheet sensor 104 detects the sheet P is defined as detection time t0. The timing at which the downstream sheet sensor 105 detects the sheet P is represented by the elapsed time from detection time t0 (detection time t3) (Figure 22).

[0081] Triggered by the detection of sheet P by the upstream sheet sensor 104, the surface quality measurement unit 103 measures the surface quality of sheet P multiple times at predetermined time intervals after a predetermined time t1 has elapsed (S6). As a result, the detected value (luminance value) for each pixel is stored in the memory of the information processing unit 160. The information processing unit 160 generates surface quality information from the stored detected values ​​and stores it in its internal memory. The measurement completion timing of the surface quality measurement unit 103 (optical sensor 150) is toout1 after the detection time t0 (measurement completion time toout1).

[0082] After a predetermined time t2 has elapsed since the upstream sheet sensor 104 detected the sheet P, the information processing unit 160 starts measuring the physical properties of the sheet P using the mechanical property measurement unit 102 (S7). The information processing unit 160 stores the basis weight information obtained from the measurement results of the ultrasonic sensor 120 in memory. If it is also desired to suppress variations in basis weight, the timing of the end of measurement by the mechanical property measurement unit 102 may be set to the measurement end time toout1.

[0083] The information processing unit 160 waits until the downstream sheet sensor 105 detects the sheet P (S8:N). When the downstream sheet sensor 105 detects the sheet P (S8:Y), the information processing unit 160 determines whether the sheet P moved (was transported) during the surface quality measurement based on the detection time t3 and the measurement end time toout1 (S31). If the detection time t3 is less than the measurement end time toout1 (S31:N), it means that the sheet P had moved to the abutment section 108 before the measurement by the surface quality measurement unit 103 was completed. In this case, the information processing unit 160 determines that the sheet P had moved to the abutment section 108 and stopped during the surface quality measurement, and that the surface quality information of the sheet P could not be accurately acquired. For this reason, the information processing unit 160 discards all information stored in memory and sends error information to the control unit 400 of the image forming apparatus 201 (S11).

[0084] If the detection time is greater than the measurement end time toout1 (S31:Y), it means that the sheet P has moved to the abutment section 108 after the measurement by the surface quality measurement unit 103 has finished. In this case, the information processing unit 160 compares the detection time t3 with the timeout time toout2 (S32). The timeout time toout2 is the upper limit of the time from when the upstream sheet sensor 104 detects the sheet P until when the downstream sheet sensor 105 detects the sheet P. The timeout time toout2 is set to be longer than the time from when the upstream sheet sensor 104 detects the sheet P until when the downstream sheet sensor 105 detects the sheet P when the sheet P is inserted normally. This process determines whether the timing when the downstream sheet sensor 105 detects the sheet P (detection time t3) is before the timeout time toout2 has elapsed.

[0085] If the timeout time toout2 has elapsed (S32:N), the information processing unit 160 determines that the sheet P has not moved to the abutment section 108 during the surface quality measurement and that the surface quality information of the sheet P has not been accurately acquired. In this case, the information processing unit 160 discards all information stored in memory and sends error information to the control unit 400 of the image forming apparatus 201 (S11). If the timeout time toout2 has not elapsed (S32:Y), the information processing unit 160 determines that the sheet P has moved to the abutment section 108 during the surface quality measurement and that the surface quality information of the sheet P has been accurately acquired. In this case, the information processing unit 160 measures the paper thickness (S9) and transmits the basis weight, surface quality information, and parameters such as paper thickness stored in memory (S12).

[0086] As explained above, based on the detection timing of each sheet P by the upstream sheet sensor 104 and the downstream sheet sensor 105, it is possible to determine whether the sheet P is moving (transporting) during surface quality measurement. If the sheet P is not moving, the information processing unit 160 determines that accurate detection values ​​have not been obtained, discards the acquired detection values, and notifies the user of the error and requests remeasurement. Through this process, the paper type identification device 100 improves the accuracy of the information (parameters) used to identify the type of sheet P. The image forming apparatus 201 using such parameters has improved sheet P identification accuracy.

[0087] Furthermore, as a configuration for detecting whether or not the sheet P is moving, a rotating body that contacts the sheet P and rotates in conjunction with the movement of the sheet P, and a known rotation detection sensor that detects whether or not the rotating body is rotating may be used. In such a structure, if the rotation detection sensor detects that the rotating body is rotating and multiple sampling data are output from the line sensor 133, the paper type identification device 100 performs paper type detection based on the sampling data. If the rotation detection sensor detects that the rotating body is rotating and only one sampling data is output from the line sensor 133, the paper type identification device 100 does not perform paper type detection based on the sampling data. Even if the rotation detection sensor detects that the rotating body is rotating and no sampling data is output, the paper type identification device 100 does not perform paper type detection based on the sampling data. If paper type detection based on sampling data is not performed, the paper type identification device 100 may notify the user that a measurement error has occurred via the operation unit 502.

Claims

1. An identification device in which, in the insertion direction in which a sheet is inserted, one end is an opening into which the sheet is inserted, and the other end is a stopper portion against which the sheet abuts. A reading sensor that reads the surface of the sheet line by line multiple times in succession, A determination means for determining whether the sheet inserted through the opening is moving based on the reading results of each pixel adjacent to the lines, obtained from the reading results of the reading sensor for each line, A means of display, and comprising, An identification device characterized in that, when the surface of a sheet is read by the reading sensor while the sheet inserted through the opening is not moving, a message indicating that the reading result is not normal is displayed on the display means.

2. The display means is characterized in that, if the sheet inserted through the opening has not moved, an instruction to reinsert the sheet is displayed. The identification device according to claim 1.

3. The reading sensor reads the surface of the sheet when the sheet inserted through the opening is not moving, and the reading result is discarded. The identification device according to claim 1.

4. The determination means is characterized by calculating the cumulative value of the difference between the reading results of each pixel adjacent to each line from the reading results of each line, and determining whether or not the sheet inserted through the opening is moving based on the calculated cumulative value. The identification device according to claim 1.

5. The determination means is characterized by calculating the cumulative value of the difference in brightness values ​​for each pixel adjacent to each line from the reading results for each line, and determining whether or not the sheet inserted through the aperture is moving based on the calculated cumulative value. The identification device according to claim 4.

6. The determination means is characterized in that it determines that the sheet inserted through the opening has not moved when the accumulated value is smaller than a predetermined threshold. The identification device according to claim 4 or 5.

7. A first detection means is provided on the upstream side in the insertion direction relative to the reading sensor and detects the sheet inserted into the opening, The system further comprises a second detection means provided downstream of the reading sensor in the insertion direction for detecting the sheet inserted into the opening. The determination means is characterized by determining whether or not the sheet inserted through the opening is moving, based on the timing at which the first detection means detects the sheet and the timing at which the second detection means detects the sheet. The identification device according to claim 1.

8. The determination means is characterized in that, if the second detection means detects the sheet before the reading sensor finishes reading, it determines that the sheet inserted through the opening has not moved. The identification device according to claim 7.

9. The determination means is characterized in that, if the second detection means detects the sheet after an upper limit of time has elapsed between the first detection means detecting the sheet and the second detection means detecting the sheet, it determines that the sheet inserted through the opening has not moved. The identification device according to claim 7 or 8.

10. The system further includes a physical property measuring unit for measuring the basis weight of the sheet, The type of sheet is identified based on the reading result from the reading sensor while the sheet is moving and the measurement result from the physical property measurement unit. An identification device according to any one of claims 1 to 9.

11. The system further includes a physical property measuring unit for measuring the thickness of the sheet. The type of sheet is identified based on the reading result from the reading sensor while the sheet is moving and the measurement result from the physical property measurement unit. An identification device according to any one of claims 1 to 9.

12. A first physical property measuring unit for measuring the basis weight of the sheet, The system further includes a second physical property measuring unit for measuring the thickness of the aforementioned sheet. The type of sheet is identified based on the reading result from the reading sensor while the sheet is moving, the measurement result from the first physical property measurement unit, and the measurement result from the second physical property measurement unit. An identification device according to any one of claims 1 to 9.

13. Components for forming an image on a sheet, The aforementioned sheet type identification device, The system includes a control means for setting the operating conditions of the components based on the type of sheet identified by the identification device, The identification device is An identification device in which, in the insertion direction in which a sheet is inserted, one end is an opening into which the sheet is inserted, and the other end is a stopper portion against which the sheet abuts. A reading sensor that reads the surface of the sheet line by line multiple times in succession, A determination means for determining whether the sheet inserted through the opening is moving based on the reading results of each pixel adjacent to the lines, obtained from the reading results of the reading sensor for each line, A means of display, and comprising, The display means is characterized in that, when the reading sensor reads the surface of the sheet while the sheet inserted through the opening is not moving, a message indicating that the reading result is not normal is displayed. Image forming apparatus.

Images