Detection device and image forming device

Abstract

To provide a paper type identification device to identify the type of sheet with high accuracy.SOLUTION: A paper type identification device 100 includes: a surface property measuring unit 103 for measuring the surface property of a sheet from a sheet being conveyed; a machine property measuring unit 102 for measuring the physical property of the sheet; an encoder 162 for outputting a pulse signal corresponding to the conveying speed of the sheet; and a paper type identification control unit 150 for identifying the sheet type based on the surface property and the physical property. The paper type identification control unit 150 determines whether or not the sheet is being transported at the standard transport speed based on the pulse signal acquisition time interval and the number of surface property measurement results acquired in the acquisition time interval, and if the sheet is not being transported at the standard transport speed, the measurement result of the surface property is converted to the measurement result measured at a position close to the readout position of when the sheet is transported at the standard transport speed.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a paper type identification device capable of identifying the type of sheet, and an image forming apparatus including such a paper type identification device.

Background Art

[0002] In image forming apparatuses such as copiers, printers, facsimiles, and multifunction peripheral devices, the types of sheets that can be used for image formation are expanding. Image forming apparatuses are required to handle various types of sheets, such as papers having various thicknesses and stiffnesses, and synthetic papers using resin instead of pulp as a raw material. <00000~10>

[0003] In an electrophotographic image forming apparatus, generally, an image is formed on a sheet conveyed through a conveyance path by performing charging, exposure, development, transfer, and fixing processes. The optimal operating conditions in each process vary depending on the physical properties (stiffness, basis weight, surface property, texture, etc.) of the sheet to be used. Therefore, the image forming apparatus performs each process under operating conditions corresponding to the type of sheet to be used, which is registered in advance. The setting of the type of sheet to be used is performed by a user operation. If the user fails to correctly set the type of sheet, an image may not be formed under appropriate operating conditions. In this case, a normal image may not be formed on the sheet.

[0004] Patent Document 1 discloses an image forming apparatus including a paper type identification device that can automatically identify the type of sheet by detecting the surface property of the sheet using a sensor. In the POD (Print On Demand) field, image forming apparatuses are adapted to small-lot production of a variety of products and perform image formation while frequently changing the sheets to be used. Also, the types of sheets used in image forming apparatuses are diverse. Thus, the image forming apparatus disclosed in Patent Document 1 is useful for coping with such diverse sheet settings and high change frequencies.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-29622 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the type of paper type identification device disclosed in Patent Document 1 cannot accurately detect the surface properties of a sheet unless the sheet transport speed is constant. In particular, the accuracy of sheet identification decreases in manual-feed type paper type identification devices where the user manually inserts the sheets. Furthermore, it is difficult to distinguish gaps between sheets.

[0007] 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]

[0008] The paper type identification device of the present invention comprises: a groove into which a sheet to be identified is inserted; a first measuring means for measuring a first characteristic of the sheet from the sheet inserted into the groove and being transported; a second measuring means for measuring a second characteristic of the sheet; an output means for outputting a signal corresponding to the transport speed of the sheet; and a determination means for acquiring a first measurement result from the first measuring means and a second measurement result from the second measuring means, and determining the type of the sheet based on the first measurement result and the second measurement result, wherein the determination means converts the first measurement result from the first measuring means based on the signal output by the output means, and determines the type of the sheet based on the converted first measurement result and the second measurement result. [Effects of the Invention]

[0009] According to the present invention, the type of sheet can be identified with high accuracy. [Brief explanation of the drawing]

[0010] [Figure 1] Diagram showing the configuration of an image forming apparatus. [Figure 2](a) and (b) are enlarged views of the fixing device 201. [Figure 3] Explanatory drawing of the control unit. [Figure 4] (a) to (c) are explanatory drawings of the paper type identification device. [Figure 5] (a) and (b) are explanatory drawings of the paper type identification device. [Figure 6] Explanatory drawing of the paper type identification device. [Figure 7] Flowchart showing parameter acquisition processing for identifying paper types. [Figure 8] Exemplary drawing of the selection screen for paper type identification processing. [Figure 9] Explanatory drawing of the relationship between ultrasonic transmittance and basis weight. [Figure 10] (a) and (b) are explanatory drawings of the method for converting detection values. [Figure 11] Flowchart showing the processing for obtaining detection values. [Figure 12] Flowchart showing paper type identification processing. [Figure 13] Explanatory drawing of the classification of surface properties. [Figure 14] Exemplary drawing of the paper selection screen. [Figure 15] Exemplary drawing of the paper selection screen. [Figure 16] Exemplary drawing of the paper type database. [Figure 17] Exemplary drawing of the paper type database.

[0011] Hereinafter, exemplary preferred embodiments of this invention will be described in detail with reference to the drawings.

[0012] (Image forming apparatus) ​FIG. 1 is a configuration diagram of the image forming apparatus according to the present embodiment. The image forming apparatus 201 according to the present embodiment is a tandem type - intermediate transfer type laser beam printer using an electrophotographic process. The image forming apparatus 201 forms and outputs a full - color or monochromatic image on a sheet P, which is a recording medium, 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.

[0013] The image forming apparatus 201 has components for forming an image inside the main body 201A, and includes an image reading device 300, an operation unit 502, and a paper type identification device 100 on the upper part of the main body 201A. A discharge space S where the sheet P after image formation is discharged is formed between the main body 201A of the image forming apparatus 201 and the image reading device 300.

[0014] 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 copying process of a document. The operation unit 502 is a user interface including 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. A user can input various instructions to the image forming apparatus 201 through the operation unit 502. The paper type identification device 100 can identify the type of the 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.

[0015] The image forming apparatus 201 includes an image forming unit 201B, an intermediate transfer unit 201C, a secondary transfer unit 201D, a fixing unit 201E, and a cassette paper feeding unit 230 inside the main body 201A.

[0016] 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.

[0017] 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 feeds the sheets P 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.

[0018] 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.

[0019] 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).

[0020] The secondary transfer unit 201D includes a secondary transfer roller 217 positioned opposite the drive roller 216a, with the intermediate transfer belt 216 in between. 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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)).

[0027] 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.

[0028] 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.

[0029] (Control Unit) Figure 3 is an explanatory diagram of the control unit that controls the operation of such an image forming apparatus 201. The image forming apparatus 201 comprises a control unit 400, an operation unit 502, and a memory 401. The paper type identification device 100 comprises a paper type identification control unit 150, an upstream sheet sensor 104, a downstream sheet sensor 105, a mechanical property measuring unit 102, a surface property measuring unit 103, and an encoder 162.

[0030] 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. The control unit 400 is located outside the image forming apparatus 201 and communicates with external devices. These external devices may include, for example, a personal computer, an image scanner, or a facsimile machine.

[0031] The control unit 400 of this embodiment 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 formation, whether paper can be fed into the image forming apparatus 201, and the usable paper feed slots.

[0032] The paper type identification device 100 includes a paper type identification control unit 150. The paper type identification control unit 150 is an information processing device implemented by, for example, a CPU, MPU, or ASIC. The paper type identification control unit 150 is connected to the control unit 400 in a communicative manner and can operate in cooperation with the control unit 400. An upstream sheet sensor 104, a downstream sheet sensor 105, a mechanical property measuring unit 102, a surface property measuring unit 103, and an encoder 162 are connected to the paper type identification control unit 150.

[0033] The upstream sheet sensor 104 detects the sheet P that has entered the paper type identification device 100. The paper type identification control unit 150 starts measuring the sheet's properties (here, mechanical properties and surface properties) upon detection of the sheet P by the upstream sheet sensor 104. The downstream sheet sensor 105 detects the sheet P that has entered the paper type identification device 100 and reached the abutment section described later. 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 121. The paper type identification control unit 150 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. The paper type identification control unit 150 measures the transport speed of the sheet P that has entered the paper type identification device 100 based on the waveform signal (pulse signal) output from the encoder 162.

[0034] The ultrasonic sensor 120 is a basis weight measuring instrument that uses ultrasound to measure the basis weight of sheet P. The paper type identification control unit 150 detects the basis weight of sheet P based on the measurement value output from the ultrasonic sensor 120. The paper thickness sensor 140 is a paper thickness measuring instrument that measures the paper thickness of sheet P. The paper type identification control unit 150 detects the paper thickness of sheet P based on the measurement value output from the paper thickness sensor 140. The detailed configurations of the ultrasonic sensor 120 and the paper thickness sensor 140 will be described later.

[0035] The optical sensor 121 images the surface of the sheet P and transmits the detected value (luminance value) for each pixel obtained as an imaging result to the paper type identification control unit 150. The paper type identification control unit 150 stores the acquired detected values. The paper type identification control unit 150 converts the stored detected values ​​into surface information such as the difference value between the detected values ​​of adjacent pixels for each pixel, brightness, and gaps. The paper type identification control unit 150 determines the gaps based on the difference between the difference values ​​between pixels aligned in the transport direction of the sheet P and the difference values ​​between pixels in a direction perpendicular to the transport direction.

[0036] The paper type identification control unit 150 transmits the measured values ​​(basis weight, paper thickness) obtained from the mechanical property measurement unit 102 and surface property information based on the detected values ​​obtained from the surface property measurement unit 103 to the control unit 400 of the image forming apparatus 201. The control unit 400 determines the type of sheet P based on the measured values ​​and surface property information obtained from the paper type identification control unit 150. The control unit 400 refers to the paper type database 402 in the memory 401 and identifies the brand name of sheet P based on the sheet type, basis weight, and paper thickness. The control unit 400 displays the identified brand name of sheet P on the display of the operation unit 502.

[0037] (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.

[0038] 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. Also, 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.

[0039] Some sheets cannot be used with the image forming apparatus 201. For example, thick cardboard with excessive stiffness may 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 when it passes through the fuser 201E, as described above. As a result, sheets P 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 201E, potentially contaminating the heating roller 220b. For this reason, it is important to identify the type of sheet P to be used for image forming in advance.

[0040] (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 4(c) is an explanatory diagram of the lower block 107 of the paper type identification device 100. Figure 6 is a view of the paper type identification device 100 from the direction in which sheet P is inserted.

[0041] The paper type identification device 100 has a groove 101 into which the sheet P to be identified is inserted. The sheet P is inserted manually by the user. The groove 101 has an upper block 106 at the top and a lower block 107 at the bottom. The upper block 106 protrudes toward the lower block 107 at the rear side of the lower block 107, forming a stopper portion 108. Because the stopper portion 108 restricts the insertion of the sheet P, the sheet P can be inserted up to the stopper portion 108. The paper type identification control unit 150 is located behind the stopper portion 108.

[0042] The lower block 107 is equipped with sheet stop rollers 160 and 161. The sheet stop rollers 160 and 161 are rotating bodies that rotate in response to the insertion of the sheet P. An encoder 162 is connected to the sheet stop roller 160. The encoder 162 is used to detect the speed of the sheet P. To this end, the encoder 162 rotates in conjunction with the rotation of the sheet stop roller 160 and outputs a pulse signal each time it rotates by a predetermined angle. The pulse signal is input to the paper type identification control unit 150. The paper type identification control unit 150 can detect the insertion speed (conveying speed) of the sheet P using the pulse signal obtained from the encoder 162.

[0043] 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 sheet P passes through the measuring unit, physical property values ​​(characteristic values) 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.

[0044] As shown in Figure 6, the mechanical property measurement unit 102 is configured such that the ultrasonic transmitter 130 is on the lower block 107 side and the ultrasonic receiver 131 is on the upper block 106 side, flanking the insertion path into which the sheet P is inserted. The ultrasonic transmitter 130 and ultrasonic receiver 131 constitute the 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]. The sheet abutment roller 160 and sheet abutment roller 161 are positioned to sandwich the ultrasonic sensor 120, stabilizing the orientation of the sheet P relative to the ultrasonic sensor 120.

[0045] Both the ultrasonic transmitter 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 transmitter 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 transmitter 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 as a measured value to the paper type identification control unit 150.

[0046] Compared to the case where there is no sheet P between the ultrasonic transmitter 130 and the ultrasonic receiver 131, the output voltage due to the ultrasound transmitted through sheet P is attenuated. The paper type identification control unit 150 calculates the transmittance of sheet P based on the ratio of the output voltage when sheet P is present and when it is not. Since the transmittance of ultrasound changes depending on the thickness of sheet P, the paper type identification control unit 150 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.

[0047] An upstream sheet sensor 104, located on the upper block 106 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 106 downstream of the surface quality measurement unit 103 in the insertion direction of sheet P, detects the arrival of sheet P at the stopper 108, which is located at the position where sheet P has been fully inserted into the paper type identification device 100.

[0048] 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 paper type identification control unit 150. The paper type identification control unit 150 measures the paper thickness of the sheet P based on the count value of the pulse signal obtained from the paper thickness sensor 140. 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.

[0049] As described above, the surface quality measuring unit 103 includes an optical sensor 121 for detecting the surface quality (e.g., surface irregularities) of the sheet P. The optical sensor 121 comprises a light-emitting unit 132, an optical system, and a line sensor 133. The optical sensor 121 is, for example, a CIS (Contact Image Sensor). The light-emitting unit 132 is, for example, an LED (Light Emitted Diode). The optical system is composed of a combination of lenses, mirrors, etc. The line sensor 133 is composed of an array of multiple light-receiving elements. The optical sensor 121 detects the surface quality of the sheet P by irradiating the surface of the sheet P with light using the light-emitting unit 132 and receiving the reflected light with the line sensor 133.

[0050] As shown in Figure 6, the surface quality measuring unit 103 is equipped with a light-emitting unit 132 and a line sensor 133 on the upper block 106 side. The surface quality measuring unit 103 needs to hold the sheet P at the optical focal position. For this purpose, a sheet abutment roller 160 is provided at a position opposite the surface quality measuring unit 103. The sort abutment roller 160 biases the sheet P toward the surface quality measuring unit 103, stabilizing the orientation of the sheet P. As a result, when the surface quality measuring unit 103 detects the surface of the sheet P, variations in the position and orientation of the sheet P are reduced, enabling stable detection of surface quality.

[0051] 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. The line sensor 133 can detect the sheet P with a resolution corresponding to the spacing between the multiple light-receiving elements. In this embodiment, the surface quality measurement unit 103 has multiple light-receiving elements arranged to achieve a resolution of 300 [dpi].

[0052] The line sensor 133 detects the surface of sheet P, with each line representing a direction perpendicular to the insertion direction of sheet P. The detection result for one line only shows local irregularities on the surface of sheet P, and therefore provides insufficient information for identifying the surface properties of the entire sheet. For this reason, the optical sensor 121 detects sheet P multiple times, one line at a time. By averaging the detection values ​​for each line obtained from multiple detections, it becomes possible to understand the overall surface property trend of sheet P. To achieve this, the optical sensor 121 measures the surface of sheet P while the sheet P being identified is moving relative to the sensor.

[0053] In this embodiment, an upstream sheet sensor 104 is positioned upstream of the surface quality measuring unit 103 in the insertion direction of the sheet P within the paper type identification device 100, and a downstream sheet sensor 105 is positioned downstream. The operation of the surface quality measuring unit 103 (optical sensor 121) is controlled according to the timing at which the upstream sheet sensor 104 and the downstream sheet sensor 105 detect the sheet P. The optical sensor 121 starts measuring the sheet P when the sheet P is inserted and moves in the insertion direction, and the upstream sheet sensor 104 detects the sheet P. The optical sensor 121 ends measuring the sheet P when the downstream sheet sensor 105 detects the sheet P. During this time, the optical sensor 121 continuously detects the surface of the sheet P one line at a time.

[0054] By using the method described above, the optical sensor 121 can accurately detect the surface properties (unevenness information) of the sheet P manually inserted by the user. By reading a predetermined area of ​​the sheet P with the optical sensor 121, it is possible to capture the surface characteristics even for sheets P with deep unevenness, such as embossed paper. In this way, the paper type identification device 100 performs a skimming scan to grasp the overall surface trend of the sheet P, enabling identification of a wide variety of sheets, including embossed paper, and thus supporting many types of paper.

[0055] (Parameter acquisition process) Figure 7 is a flowchart showing the parameter acquisition process for obtaining information (parameters) to identify the paper type of sheet P. Figure 8 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.

[0056] When the control unit 400 receives information from the operation unit 502 indicating that the "Automatic Sheet Identification" button has been selected, the operation mode is set to the automatic sheet identification mode for sheet P (S1). Once set to automatic identification mode, the control unit 400 notifies the paper type identification control unit 150 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 the physical properties of sheet P (S2).

[0057] When the control unit 400 instructs the paper type identification control unit 150 to measure the physical properties of sheet P, it performs initialization processing of the mechanical property measurement unit 102 and the surface property measurement unit 103 in preparation for inserting sheet P (S3). When the user starts inserting sheet P into the groove 101 (S4), the paper type identification control unit 150 waits until the upstream sheet sensor 104 detects sheet P (S5:N). Triggered by the timing of the upstream sheet sensor 104 detecting sheet P (t=0) (S5:Y), the paper type identification control unit 150 starts measuring the physical properties of sheet P.

[0058] First, the paper type identification control unit 150 starts measuring the surface properties of sheet P using the surface properties measurement unit 103 (optical sensor 121) after a predetermined time (t=t1) has elapsed since the upstream sheet sensor 104 detected sheet P (S6). The paper type identification control unit 150 causes the optical sensor 121 to continuously read sheet P line by line as it is being transported, and acquires the reading results (detected values) sequentially. While acquiring the detected values, the paper type identification control unit 150 acquires a pulse signal from the encoder 162 and measures the transport distance of sheet P based on this pulse signal. The paper type identification control unit 150 acquires profile data for each detected value based on the transport distance of sheet P and the reading times of the detected values ​​acquired sequentially from the optical sensor 121. Details of the profile data will be described later.

[0059] The paper type identification control unit 150 converts the acquired multiple detection values ​​into data with equally spaced lines at the detection locations using profile data. Details of this conversion method will be described later. Based on the data obtained through the conversion, the paper type identification control unit 150 calculates surface properties information representing the surface properties of sheet P. The paper type identification control unit 150 stores the calculated surface properties information in its internal memory. The surface properties information includes information such as adjacent pixel difference integral values, brightness, and gaps, which will be described later.

[0060] The paper type identification control unit 150 starts measuring the physical properties of sheet P using the mechanical property measurement unit 102 after a predetermined time (t=t2) has elapsed since the upstream sheet sensor 104 detected sheet P (S7). The paper type identification control unit 150 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, similar to the surface property information. Figure 9 is an explanatory diagram of the relationship between ultrasonic transmittance (transmission coefficient) and basis weight. The paper type identification control unit 150 maintains a conversion formula or conversion table that shows the relationship between ultrasonic transmittance and basis weight. The paper type identification control unit 150 performs the conversion from measured value to basis weight using such a conversion formula or conversion table. Furthermore, the paper type identification control unit 150 enters a standby state for the pulse signal output from the paper thickness sensor 140, triggered by sheet detection by the upstream sheet sensor 104.

[0061] The paper type identification control unit 150 determines whether the elapsed time since the upstream sheet sensor 104 detected sheet P is within a predetermined timeout period (t=tout) (S8). If it is within the timeout period (S8:Y), the paper type identification control unit 150 checks whether the downstream sheet sensor 105 near the stopper 108 has detected sheet P inserted by the user (S10). The downstream sheet sensor 105 detects sheet P when it has been inserted to the innermost stopper 108. If the downstream sheet sensor 105 has not detected sheet P (S10:N), the paper type identification control unit 150 returns to the process of S8. If the downstream sheet sensor 105 has detected sheet P (S10:Y), the paper type identification control unit 150 measures the paper thickness of sheet P based on the number of pulse signals obtained from the paper thickness sensor 140 (number of pulses) (S11). The paper thickness of sheet P is stored in the memory of the paper type identification control unit 150. When the downstream sheet sensor 105 detects sheet P, the paper type identification control unit 150 stops reading sheet P by the optical sensor 121.

[0062] The paper type identification control unit 150 determines that, because the downstream sheet sensor 105 detected sheet P before the timeout period, sheet P moved during measurement by the surface properties measurement unit 103 and that correct data has been acquired. In this case, the paper type identification control unit 150 determines that all measurements on sheet P have been completed successfully and notifies the control unit 400 of the image forming apparatus 201 that the process has been completed successfully. At this time, the paper type identification control unit 150 transmits parameters such as basis weight, surface properties information, and paper thickness stored in memory (S12). These parameters are information for identifying the type of sheet P.

[0063] If the timeout period elapses after the upstream sheet sensor 104 detects sheet P (S8:N), the paper type identification control unit 150 determines that accurate data regarding the surface properties of sheet P has not been obtained. In this case, the paper type identification control unit 150 determines that all data stored in memory is invalid and discards it. The paper type identification control unit 150 also sends error information to the control unit 400 of the image forming apparatus 201 (S9). In other words, the paper type identification control unit 150 decides whether or not to delete the data stored in memory depending on whether or not the downstream sheet sensor 105 detects sheet P within the timeout period after the upstream sheet sensor 104 detects sheet P. In this case, the control unit 400 displays a screen on the operation unit 502 display prompting the user to reinsert sheet P into the paper type identification device 100. Once the user confirms the reinsertion instruction via the operation unit 502, the control unit 400 returns to the S2 process and instructs the paper type identification control unit 150 to measure sheet P. Subsequently, the processes from S3 onwards are repeated.

[0064] (Conversion to data with equal distance intervals) The detection values ​​acquired by the optical sensor 121 are obtained by detecting one line at a time at equal intervals along the insertion direction of the sheet P, provided that the insertion speed (conveyor speed) of the sheet P is constant. However, if the insertion speed of the sheet is not constant, the detection values ​​will be obtained with the intervals between detection positions for each line varying along the insertion direction of the sheet P. In order to accurately identify the surface features of the sheet P in the insertion direction, it is preferable that the intervals between detection positions for one line be equal at a predetermined distance. Figures 10 and 11 are explanatory diagrams of a method for converting detection values ​​into detection values ​​measured by equalizing the detection positions for one line.

[0065] Figure 10(a) is a timing chart for detecting the surface of sheet P by the surface quality measurement unit 103 (optical sensor 121). Figure 10(b) is an example of profile data showing the attributes of the detected values ​​of the surface of sheet P by the optical sensor 121.

[0066] "VD" is a reference signal used by the optical sensor 121 to initiate multiple sheet P reading operations. "HD" is a reference signal used to initiate a single reading operation. VD and HD are generated by a timing generator in the surface quality measurement unit 103. For example, the surface quality measurement unit 103 outputs a low signal VD in response to an operation start instruction received from the paper type identification control unit 150, triggered by sheet detection by the upstream sheet sensor 104. After outputting the low signal VD, the surface quality measurement unit 103 outputs HD, which transitions between high and low at predetermined time intervals (Δt / 2). The optical sensor 121 irradiates and receives light based on these reference signals and outputs the detected value. In Figure 10(a), the optical sensor 121 performs a reading operation every Δt and outputs the detected value.

[0067] "SE" is a pulse signal output from encoder 162. Encoder 162 outputs a pulse signal each time it rotates by a predetermined angle as sheet P is inserted (transported). In other words, encoder 162 outputs a pulse signal each time sheet P inserted into paper type identification device 100 moves a predetermined distance. In Figure 10(a), encoder 162 outputs a pulse signal each time sheet P moves a distance L. Paper type identification control unit 150 can detect the insertion speed (transport speed) of sheet P based on the distance L and the time interval for acquiring pulse signals from encoder 162.

[0068] If the falling edge of the HD is used as the start timing for the reading operation, the optical sensor 121 outputs the detected value Ld(1) at time t001 and the detected value Ld(2) at time t002. Here, we focus on the detected value after the rising edge of the pulse signal (SE) output from the encoder 162, using the rising edge of the pulse signal as a reference.

[0069] Between time t002, when the detected value Ld(2) is output, and time t008, when the detected value Ld(8) is output, sheet P is transported a distance L. In other words, the optical sensor 121 performs reading processing for 6 lines over the distance L from time t002 to time t008. Similarly, the optical sensor 121 performs reading processing for 5 lines over the distance L from time t008 to time t013, and for 4 lines over the distance L from time t013 to time t017.

[0070] When sheet P is transported at a standard insertion speed, if the optical sensor 121 performs reading processing for 5 lines over a distance L, between times t002 and t008, the insertion speed of sheet P is slow, resulting in an extra line of reading processing being performed. Between times t013 and t017, the insertion speed of sheet P is fast, resulting in a shortage of reading processing for 1 line.

[0071] The paper type identification control unit 150 calculates profile data shown in Figure 10(b) so that it can determine whether the detected value obtained from the optical sensor 121 is the result of detection by a sheet P being transported at a standard insertion speed. The profile data consists of the detected value Ld(i), line group Ldg, line group number LdgNo, line group personnel number Ldgq, and distance m(i) from the leading line of the line group.

[0072] The detected values ​​Ld(i) are assigned the number i in the order they are output from the optical sensor 121. The line group Ldg for detected value Ld(1) output before encoder 162 outputs a pulse signal is set to "0". For detected value Ld(i) output after encoder 162 outputs a pulse signal, the line group Ldg is set to the number of pulse signals output (line group). Line group Ldg becomes the group name of detected value Ld(i). From line group Ldg, it is determined which pulse signal followed the output of detected value Ld(i).

[0073] The line group number LdgNo indicates the order in which the detected value Ld(i) was output from the optical sensor 121 within the line group Ldg to which it belongs. The line group member count Ldgq indicates the number of detected values ​​Ld(i) within the line group Ldg. The distance m(i) is the distance from the first detected value in the line group Ldg to which the detected value Ld(i) belongs, calculated assuming that the detected values ​​Ld(i) are read and output at equally spaced detection positions. The distance m(i) is expressed by the following formula. m(i) = L*(LdgNo-1) / Ldgq

[0074] The paper type identification control unit 150 uses this profile data to convert multiple detection values ​​obtained from the optical sensor 121 into data for cases where the detection positions are equally spaced. Figure 11 is a flowchart illustrating the process of converting multiple detection values ​​into data for cases where the detection positions are equally spaced.

[0075] The paper type identification control unit 150 initializes parameters i and j (S21). The paper type identification control unit 150 determines whether line group Ldg is "0" or not (S22). If line group Ldg is not "0" (S22:Y), the paper type identification control unit 150 determines whether the number of line group members Ldgq is n_goal or not (S23). n_goal indicates the number of detected values ​​output between pulse signals continuously output from encoder 162 when sheet P is transported at a reference insertion speed (in Figure 10(a), n_goal=5). In the process of S23, it is determined whether sheet P is being transported at a reference insertion speed or not.

[0076] If the line group personnel count Ldgq is not n_goal (S23:N), the paper type identification control unit 150 determines that the sheet P is not being transported at the standard insertion speed. In this case, the paper type identification control unit 150 determines whether the line group number LdgNo is "1" (S24). Here, the paper type identification control unit 150 determines whether it is the first detected value of the line group Ldg (the first detected value after acquiring the pulse signal).

[0077] If the line group number LdgNo is not "1" (S24:N), the paper type identification control unit 150 initializes the parameter n (S25). The paper type identification control unit 150 calculates the distance m(i+K) at which the detection position is closest to L*n / n_goal within the line group Ldg to which it belongs, among the detected values ​​Ld(i) to Ld(i+Ldgq-2) (S26). In this case, the "detection position" is the distance from the first detected value of the line group Ldg to which it belongs. "K" is a natural number between 0 and (Ldgq-2) (0≦K≦Ldgq-2). In other words, the paper type identification control unit 150 calculates the distance m(i+K) at which the detection position of the sheet P being transported at the standard insertion speed is closest to the distance L*n / n_goal from the detection position of the first detected value of the line group Ldg. The paper type identification control unit 150 extracts the detected value Ld(i+K) corresponding to the distance m(i+K) from the profile data and converts it into data Ld_out(j+n-1) (S27).

[0078] The paper type identification control unit 150 increments parameter n by 1 (S28). The paper type identification control unit 150 determines whether parameter n is (n_goal-1) or not (S29). If parameter n is not (n_goal-1) (S29:N), the paper type identification control unit 150 repeats the process from S26 onward until parameter n becomes (n_goal-1). As a result, all detected values ​​Ld(i+K) within line group Ldg are converted into data Ld_out(j+n-1).

[0079] If parameter n is (n_goal-1) (S29:Y), the paper type identification control unit 150 adds (dgq-1) to parameter i and (n_goal) to parameter j (S30). Through processing from S25 to S30, the detection value output from the optical sensor 121 that is closest to the read position when sheet P is transported at the standard insertion speed is picked up as data Ld_out(j). In other words, if sheet P is not transported at the standard insertion speed, the detection value Ld(i) is converted to a detection value Ld(i+K) that is closer to the read position when sheet P is transported at the standard insertion speed.

[0080] If the number of line group personnel Ldgq is not n_goal (S23:N) and the line group number LdgNo is "1" (S24:Y), the paper type identification control unit 150 uses the detected value Ld(i) as is as data Ld_out(j) (S31). In other words, even if sheet P is not being transported at the standard insertion speed, the paper type identification control unit 150 uses the detected value Ld(i) at the beginning of line group Ldg as data Ld_out(j). Furthermore, even when the number of line group personnel Ldgq is n_goal (S23:Y), the paper type identification control unit 150 uses the detected value Ld(i) as data Ld_out(j) (S31). In other words, when sheet P is being transported at the standard insertion speed, the paper type identification control unit 150 uses the detected value Ld(i) as data Ld_out(j).

[0081] Subsequently, the paper type identification control unit 150 increments parameter j by 1 (S32) and parameter i by 1 (S33). If line group Ldg is "0" (S22:N), the paper type identification control unit 150 increments parameter i by 1 (S33).

[0082] The paper type identification control unit 150 repeatedly performs the processing from S23 onwards if parameter i is not "i_max" (S34:N), and terminates the processing if parameter i is "i_max" (S34:Y). "i_max" is the total number of detected values ​​output from the optical sensor 121.

[0083] The data Ld_out(j) obtained through the above processing is the detected value with the detection position converted to equal intervals. The paper type identification control unit 150 calculates brightness, adjacent pixel difference integrated value, gaps, etc. from the data Ld_out(j) and stores them in the memory within the paper type identification control unit 150 as surface property information. The adjacent pixel difference integrated value is the value obtained by integrating the differences in the detected values ​​of adjacent light-receiving elements of the line sensor 133.

[0084] The control unit 400 of the image forming apparatus 201 acquires surface information, basis weight, and paper thickness from the paper type identification control unit 150 as parameters for identifying the type of sheet P. The control unit 400 identifies the type of sheet P based on the acquired parameters. Figure 12 is a flowchart representing the paper type identification process.

[0085] The control unit 400 classifies the type of sheet P based on the measurement results (surface quality information) of the surface quality of sheet P (S41). Figure 13 is an explanatory diagram of the surface quality classification. In Figure 13, a matrix is ​​used as an index of surface quality, with the vertical axis representing the integrated difference value of adjacent pixels and the horizontal axis representing brightness. The surface quality of each sheet P is measured in advance and classified. The control unit 400 refers to the matrix according to the integrated difference value of adjacent pixels and brightness obtained from the detection values ​​acquired by the optical sensor 121 to identify the type of sheet P.

[0086] Brightness is the integrated value (brightness) of the detection values ​​of each pixel of the line sensor 133, 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, which has a geometric uneven shape on its surface, such as embossed paper, has a large difference in brightness between adjacent pixels due to the unevenness, so the integrated difference value of adjacent pixels is large. 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 tends to have a small integrated difference value of adjacent pixels because the unevenness appears less due to the coating layer on the surface.

[0087] In this way, the control unit 400 can classify the surface properties of sheet P from the detected values ​​(luminance information) of each pixel of the line sensor 133, and classify sheet P according to the sheet classification used in the image forming apparatus 201. The control unit 400 classifies the type of sheet P based on its surface properties by determining which classification in the matrix of Figure 13 the adjacent pixel difference integrated value and brightness belong to.

[0088] The control unit 400 determines the type of sheet P by adding basis weight to the classification by surface properties (S42). 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 (S43). 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. Coated paper has a higher density than plain printing paper, which is mainly composed of pulp, so even with the same basis weight, the paper thickness tends to be thinner. Therefore, by simultaneously using paper thickness as a parameter for identifying the paper type, the accuracy of identifying the sheet P is improved. In particular, adding paper thickness information is useful for identifying the brand of sheet P. The control unit 400 identifies the paper type of sheet P based on these parameters (S44).

[0089] Figures 14 and 15 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 identified in process S44 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 S44 using the paper selection screen.

[0090] The paper selection screen in Figure 14 displays the types of sheet settings that can be selected for each sheet category pre-configured in the image forming apparatus 201. Due to variations in basis weight, sheet P may be classified into a sheet category different from its nominal basis weight. Therefore, the paper selection screen also displays categories close to the detected sheet category. In addition, the word "Recommended" is displayed for paper types identified in the S44 process. The paper selection screen in Figure 15 allows the selection of sheet brands. Sheet settings are configured by specifying the sheet brand. The user assigns the sheet setting to the paper feed stage by selecting a sheet from these sheet categories and sheet brands using the operation unit 502. This ensures that the type of sheet P is accurately identified, enabling printing under the correct operating conditions.

[0091] Figures 16 and 17 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 17, 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 15 and 16 on the display of the operation unit 502. This allows the user to easily set the sheet.

[0092] 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 402 in Figure 16. 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.

[0093] As described above, the image forming apparatus 201 of this embodiment identifies the type of sheet P used for image forming using a manual feed type paper type identification device 100. The paper type identification device 100 can accurately measure changes in the surface properties of the sheet P in the insertion direction, even when the insertion speed (transport speed) of the manually fed sheet P is not stable. Therefore, the paper type identification device 100 can improve the accuracy of identifying the type of sheet P and can also distinguish gaps in the sheet P.

[0094] In this embodiment, the paper type identification device 100 is equipped with a paper type identification control unit 150, which processes the measurement results of the physical properties of the sheet P by 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 paper type identification control unit 150 would be included in the control unit 400. In addition, 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.

[0095] In this embodiment, the image forming apparatus 201 is equipped with the paper type database 402, but the paper type identification device 100 may also be equipped with the paper type database 402. In this case, the paper type identification control unit 150 of the paper type identification device 100 will perform the task of identifying the brand of sheet P, which is performed by the control unit 400. Furthermore, although an example using the upstream sheet sensor 104 as a trigger has been described, it is also possible to use the downstream sheet sensor 105 as a 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.

[0096] 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.

Claims

1. A detection device having an opening at one end for inserting a sheet and an abutment at the other end against which the sheet abuts, in an insertion direction in which the sheet is inserted, A reading sensor that reads the surface of the moving sheet at a plurality of positions; an output means for outputting a signal corresponding to a sheet conveying speed; a control means for dividing the number of data pieces read by the reading sensor into a plurality of regions in accordance with the signal output from the output means; The control means adjusts the number of data included in each of the plurality of regions to a reference number of data. Detection device.

2. The output means outputs the signal at intervals according to the conveying speed, the control means sets the number of data of the reading result from when the signal is acquired from the output means to when the next signal is acquired when the sheet moves at a reference speed as the reference number of data. The detection device of claim 1 .

3. The reading sensor continuously reads the surface of the sheet moving from the opening to the abutment portion, line by line, at a predetermined time interval; the output means outputs the signal each time the sheet moves a predetermined distance; the control means adjusts the number of data of the read result from when the signal is acquired from the output means to when the next signal is acquired, to the reference number of data. The detection device of claim 2.

4. A recording device comprising: a memory means for storing a plurality of reference reading positions at which reading is performed by the reading sensor during a period from when the output means outputs a first signal to when the output means outputs a subsequent second signal when the sheet moves at a reference speed; the control means, in a state in which the sheet is moving at a speed different from a reference speed, extracts a reading result of a reading position closest to the reference reading position from among a plurality of reading results read by the reading sensor during a period from when the output means outputs the first signal to when the output means outputs the second signal, thereby aligning the number of data included in each of the plurality of regions to the reference number of data. The detection device of claim 3.

5. The storage means stores the plurality of reference reading positions as distances based on an initial reading position after the output means outputs a first signal when the sheet moves at the reference speed, The control means, in a state where the sheet is moving at a speed different from a reference speed, extracts a reading result, the distance of which based on a first reading position after the first signal is outputted, from among the multiple reading results read by the reading sensor during a period from when the output means outputs the first signal to when the output means outputs the second signal, closest to the distance stored in the storage means, thereby aligning the number of data included in each of the multiple areas to the reference number of data.

5. The detection device of claim 4.

6. The control means is characterized in that, when the sheet is moving at a speed different from a reference speed, during the period from when the output means outputs the first signal to when it outputs the second signal, among the multiple reading results read by the reading sensor, the first reading result by the reading sensor after the first signal is included in the reference number of data. The detection device of claim 5.

7. A measuring unit for measuring physical properties of the sheet; and a determination unit for determining the type of the sheet based on the result of the data set being aligned to the reference number and the physical properties measured by the measurement unit. The detection device of claim 1 .

8. The detection device as described in Claim 7, characterized in that the measuring unit is a sensor that measures the basis weight of the sheet.

9. The detection device as described in Claim 7, characterized in that the measuring unit is a sensor that measures the paper thickness of the sheet.

10. The device further includes a rotating body that rotates due to the sheet being inserted, The output means rotates with the rotation of the rotating body, and outputs the signal every time the output means rotates by a predetermined angle. The detection device of claim 1 .

11. The output means is an encoder connected to the rotating body, and outputs a pulse signal as the signal. The sensing device of claim 10.

12. A first detection means is provided upstream of the reading sensor in a conveying direction of the sheet, and detects the sheet inserted into the opening; a second detection unit that is provided downstream of the reading sensor in a sheet conveying direction and detects the sheet inserted into the opening; the control means causes the reading sensor to start reading the sheet when the first detection means detects the sheet, and causes the reading sensor to end reading the sheet when the second detection means detects the sheet. The detection device of claim 1 .

13. A detection device having an opening at one end side through which the sheet is inserted and an abutment portion at the other end side against which the sheet abuts, in an insertion direction in which the sheet is inserted, A reading sensor that reads the surface of the moving sheet at a plurality of positions; an output means for outputting a signal corresponding to a sheet conveying speed; a control means for dividing the number of data pieces read by the reading sensor into a plurality of regions in accordance with the signal output from the output means; The control means adjusts the number of data included in each of the plurality of areas to be the same. Detection device.

14. A component for forming an image on a sheet; The detection device according to claim 1 or 13, Image forming device.

Images