Sheet detection apparatus and image forming apparatus

Abstract

The invention relates to a sheet detecting apparatus and an image forming apparatus. The sheet detecting apparatus includes: a measuring unit configured to measure a sheet; and a power supply voltage controller configured to control a supply of the power supply voltage to the measurement unit, in which the power supply voltage controller is configured to start supplying the power supply voltage to the measurement unit upon receiving a notification indicating that a mode for performing sheet measurement is set.

Description

Technical Field

[0001] The present disclosure relates to a sheet detection device including a media sensor for discriminating a type of a sheet (sheet type) and an image forming apparatus including such a sheet detection device. Background Art

[0002] For copiers, printers, multi-function peripherals and other such image forming devices, the types of sheets that can be used are constantly increasing. For example, an image forming device can print images on various types of sheets, such as sheets with various thicknesses and rigidities and synthetic paper sheets using resin instead of pulp as raw materials. Generally speaking, an electrophotographic image forming device prints an image on a sheet through the steps of charging, exposure, development, transfer and fixing. The optimal operating conditions (image forming conditions) in each step are different depending on the physical properties (e.g., rigidity, basis weight and surface properties) of the sheet to be used. Therefore, the image forming device needs to perform a printing process based on the image forming conditions corresponding to the type of sheet.

[0003] For example, the type of sheet is usually set manually by a user. However, in the case of manually setting the type of sheet, the type of sheet may not be set correctly due to reasons such as user error. In this case, the printing process is not performed based on appropriate image forming conditions, so a correct image may not be formed. In U.S. Patent No. 8,045,868, an image forming apparatus is disclosed that forms an image by using a media sensor to automatically discriminate the type of sheet.

[0004] When discriminating the type of sheet material, a media sensor measures the physical properties of the sheet material as a feature quantity. The measurement result obtained by the media sensor has a temperature characteristic. That is, the measurement result of the media sensor fluctuates due to the temperature change of the media sensor itself. This leads to a decrease in the accuracy of discriminating the type of sheet material, and makes it difficult to set appropriate image forming conditions. The present disclosure is made in view of the above-mentioned problems, and the main purpose of the present disclosure is to provide a sheet material detection device that suppresses the influence of temperature changes on the measurement result of the media sensor. Summary of the invention

[0005] According to one embodiment of the present disclosure, a sheet material detection device includes: a measuring component configured to measure a sheet material; and a power supply voltage control component configured to control the supply of a power supply voltage to the measuring component, wherein the power supply voltage control component is configured to start supplying the power supply voltage to the measuring component when receiving a notification indicating that a mode for performing sheet material measurement is set.

[0006] According to another embodiment of the present disclosure, a sheet detection device includes: a conveying component configured to convey a sheet; a measuring component configured to measure a sheet conveyed by the conveying component; a sheet detection sensor component configured to detect a sheet conveyed by the conveying component; and a power supply voltage control component configured to control the supply of power supply voltage to the measuring component, wherein the power supply voltage control component is configured to start supplying power supply voltage to the measuring component when the sheet detection sensor component detects a sheet.

[0007] According to another embodiment of the present disclosure, a sheet material detection device includes: a measuring component configured to measure a sheet material; and a power supply voltage control component configured to control the supply of power supply voltage to the measuring component, wherein the power supply voltage control component is configured to start supplying power supply voltage to the measuring component when an instruction to start a job is obtained.

[0008] According to another embodiment of the present disclosure, an image forming device includes: a sheet detection component, which includes: a measuring component configured to measure the sheet; and a power supply voltage control component configured to control the supply of power supply voltage to the measuring component; an image forming component configured to form an image on the sheet by using an image forming condition based on a result of the measuring component measuring the sheet; and a delivery space to which the sheet on which the image is formed is to be delivered, wherein the power supply voltage control component is configured to start supplying the power supply voltage to the measuring component when receiving a notification indicating that a mode for performing sheet measurement is set.

[0009] Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a configuration diagram of an image forming apparatus.

[0011] Figure 2A and Figure 2B is an enlarged view of the fixing device.

[0012] Figure 3 is an illustrative diagram of a controller.

[0013] Figure 4 is an explanatory view of the construction of the media sensor.

[0014] Figure 5 is an explanatory view of the construction of the media sensor.

[0015] Figure 6 : is a graph showing the temperature characteristics of the output value of the ultrasonic sensor.

[0016] Figure 7 is a flowchart illustrating an image forming process.

[0017] Figure 8 is an illustrative graph of the relationship between transmittance and basis weight.

[0018] Fig. 9 It is a classification table of sheet material types.

[0019] Fig.10 It is a classification table of sheet material types.

[0020] Fig.11 It is a classification table of sheet material types.

[0021] Fig.12 is an exemplary view of the automatic detection mode setting screen.

[0022] Fig.13 is an exemplary diagram of a modified example of the controller.

[0023] Fig.14 is a flowchart for illustrating image forming processing.

[0024] Fig.15 is a flowchart for illustrating image forming processing.

[0025] Fig.16 is a flowchart for illustrating image forming processing. DETAILED DESCRIPTION

[0026] Now, at least one exemplary embodiment of the present disclosure will be described with reference to the accompanying drawings.In the following description, "basis weight" is the mass per unit area of ​​a sheet, and is expressed in gsm.

[0027] <Image Forming Apparatus>

[0028] Figure 1 201 is a configuration diagram of an image forming apparatus according to at least one embodiment. An image forming apparatus 201 according to at least one embodiment is, for example, a tandem intermediate-transfer type laser beam printer using an electrophotographic process. The image forming apparatus 201 forms a full-color image or a monochrome image on a sheet S as a recording medium, and outputs the sheet S based on image data acquired from an external device such as a personal computer via a network or based on image data acquired from an image reading device 202 provided on top of the image forming apparatus 201.

[0029] The image forming apparatus 201 has components for forming an image inside a main body 201A, and includes an image reading device 202 and an operation unit 502 on top of the main body 201A. A delivery space D including a placement portion 223 for receiving a sheet S to be delivered thereto after image formation is defined between the main body 201A of the image forming apparatus 201 and the image reading device 202.

[0030] The image reading device 202 is a reader that reads an image from a manuscript to generate image data. The image reading device 202 is used, for example, in a process of copying a manuscript. The image reading device 202 in at least one embodiment is configured as a part of the image forming apparatus 201. However, the image reading device 202 is not limited to this configuration, and the image reading device 202 may be electrically connected to the image forming apparatus 201 as a device different from the image forming apparatus 201.

[0031] The operation unit 502 is a user interface including an input interface and an output interface. Examples of the input interface include various key buttons and a touch panel. Examples of the output interface include a display and a speaker. The user can input various instructions to the image forming device 201 via the operation unit 502. The image forming device 201 notifies the user of various types of information by displaying various screens on the display of the operation unit 502. The operation unit 502 in at least one embodiment is configured as part of the image forming device 201. The operation unit 502 is not limited to this configuration, and the operation unit 502 can be electrically connected to the image forming device 201 as a device different from the image forming device 201.

[0032] The image forming apparatus 201 includes an image forming unit 201B, an intermediate transfer unit 201C, a secondary transfer unit 201D, a fixing device 201E, and a cassette sheet feeding unit 230 in a main body 201A. The main body 201A includes a manual sheet feeding unit 235.

[0033] The cassette sheet feeding units 230 each feed a sheet S from a corresponding one of the sheet feeding cassettes 1 that accommodates the sheet S. The cassette sheet feeding unit 230 includes a pickup roller 2 and a separation unit. The separation unit includes a feed roller 3 and a slowing roller 4 for separating the sheet S sent out from the pickup roller 2. The sheets S are fed one by one from the sheet feeding cassette 1 by the pickup roller 2 and the separation unit. In at least one embodiment, a configuration is described in which a plurality of (four in this example) cassette sheet feeding units 230 are provided. However, any number of cassette sheet feeding units 230 may be provided. The sheet S fed from the cassette sheet feeding unit 230 is conveyed to the registration roller pair 240 via the conveying roller pair 280 and the conveying roller pair 290.

[0034] The sheet S may be fed from a unit other than the cassette sheet feeding unit 230, that is, from the manual sheet feeding unit 235. The manual sheet feeding unit 235 includes a manual sheet feeding tray 5 for receiving the sheet S placed by the user. Similar to the cassette sheet feeding unit 230, the manual sheet feeding unit 235 includes a pickup roller and a separation unit, and the sheets S are fed one by one from the manual feeding tray 5. The sheet S fed from the manual sheet feeding unit 235 is also conveyed to the registration roller pair 240 via the conveying roller pair 280 and the conveying roller pair 290. The conveying roller pair 280 and the conveying roller pair 290 are rotating members for conveying the sheet S.

[0035] The media sensor 100 for measuring the characteristic amount of the sheet S is arranged on the conveying path between the conveying roller pair 280 and the conveying roller pair 290. The conveying roller pair 280 is arranged on the upstream side of the media sensor 100 in the conveying direction of the sheet S, and the conveying roller pair 290 is arranged on the downstream side of the media sensor 100 in the conveying direction of the sheet S. The media sensor 100 outputs, for example, information corresponding to the basis weight (basis weight information) and information corresponding to the surface property (surface property information) as the characteristic amount of the sheet S conveyed from the cassette sheet feeding unit 230 or the manual sheet feeding unit 235. The media sensor 100 may be arranged at least one or both of a position where the sheet S fed from the cassette sheet feeding unit 230 can be measured and a position where the sheet S fed from the manual sheet feeding unit 235 can be measured. The configuration details of the media sensor 100 will be described later.

[0036] The image forming unit 201B is a four-drum full-color type, and includes a laser scanner 210 and four process boxes 211. The four process boxes 211 form toner images of four colors, specifically, toner images of yellow (Y), magenta (M), cyan (C), and black (K). Each process box 211 includes a photosensitive drum 212, a charging device 213, and a developing device 214. A toner box 215 is arranged above the process box 211. The toner box 215 replenishes toner for the corresponding developing device 214.

[0037] The intermediate transfer unit 201C includes an intermediate transfer belt 216 wound around a driving roller 216a and a tension roller 216b. Inside the intermediate transfer belt 216, four primary transfer rollers 219 are provided to abut against the intermediate transfer belt 216 at positions opposite to the photosensitive drum 212. The intermediate transfer belt 216 is rotated in the direction of the arrow by the driving roller 216a driven by a driving unit (not shown).

[0038] The secondary transfer unit 201D includes a secondary transfer roller 217, which is arranged to sandwich the intermediate transfer belt 216 at a position opposite to the driving roller 216a. The fixing device 201E is arranged on the downstream side of the secondary transfer roller 217 in the sheet S conveying direction, and includes a pressure roller 220a and a heating roller 220b. On the downstream side of the fixing device 201E in the sheet S conveying direction, a first delivery roller pair 225a, a second delivery roller pair 225b and a double-sided printing reversing unit 201F are arranged. The double-sided printing reversing unit 201F includes a reversing roller pair 222 and a re-transfer path R. The reversing roller pair 222 can rotate in the forward direction and the reverse direction. The re-transfer path R allows the sheet S having an image formed on one side thereof to be conveyed to the image forming unit 201B.

[0039] The image forming apparatus 201 having the configuration described above operates as follows. The image forming apparatus 201 acquires image data and an instruction to start a print job from the image reading apparatus 202 or from an external device, and forms an image corresponding to the image data on a sheet S. At this time, the image forming apparatus 201 performs each step of image formation based on an image forming condition given according to the characteristics of the sheet S. A print job is a series of operations performed based on a print signal indicating that an image is to be formed on a sheet S, in which the sheet S is conveyed and an image is formed thereon, and after the image forming operation is completed, the sheet S is delivered to the placement portion 223. The image forming apparatus 201 acquires an instruction to start a print job from the operation unit 502 or an external device.

[0040] The image forming unit 201B uniformly charges the surface of the photosensitive drum 212 to a potential having a predetermined polarity using the charging device 213. The laser scanner 210 irradiates the uniformly charged surface of the photosensitive drum 212 with a corresponding laser beam modulated based on image data. In this way, electrostatic latent images of corresponding colors (yellow, magenta, cyan, and black) are formed on the respective surfaces of the photosensitive drum 212.

[0041] The image forming unit 201B develops the electrostatic latent image formed on the photosensitive drum 212 using the developing device 214. The electrostatic latent image is developed on the photosensitive drum 212 using the toner of the corresponding color, so that a toner image of the corresponding color is formed on the photosensitive drum 212. The toner image is sequentially transferred from the photosensitive drum 212 to the rotating intermediate transfer belt 216 in a superimposed manner by the primary transfer roller 219. In this way, a full-color toner image is formed on the intermediate transfer belt 216. The intermediate transfer belt 216 rotates to convey the toner image to the secondary transfer unit 201D.

[0042] Simultaneously with this operation of forming the toner image, the cassette sheet feeding unit 230 or the manual sheet feeding unit 235 conveys the sheets S one by one to the registration roller pair 240. Before the sheets S reach the registration roller pair 240, the medium sensor 100 measures the characteristic amount of the sheets S. The image forming apparatus 201 sets the image forming conditions based on the measured characteristic amounts, and performs subsequent image formation based on the set image forming conditions. The image forming conditions to be set include, for example, the voltage value of the secondary transfer bias applied to the secondary transfer roller 217 during the transfer of the toner image to the sheet S, the fixing temperature when the fixing device 201E fixes the image, and the conveying speed of the sheet S during the fixing.

[0043] The registration roller pair 240 performs skew correction on the sheet S conveyed to the registration roller pair 240. After the skew correction, the sheet S is conveyed to the secondary transfer unit 201D by the registration roller pair 240 in synchronization with the timing at which the toner image carried on the intermediate transfer belt 216 is conveyed to the secondary transfer unit 201D. The secondary transfer unit 201D transfers the full-color toner image from the intermediate transfer belt 216 to the sheet S using a secondary transfer bias applied to the secondary transfer roller 217.

[0044] The sheet S to which the toner image is transferred is conveyed to the fixing device 201E. The fixing device 201E pinches and conveys the sheet S through a roller nip portion defined by the pressure roller 220a and the heating roller 220b. The fixing device 201E heats the sheet S through the heating roller 220b while pinching and conveying the sheet S, thereby melting and mixing the toners of the corresponding colors on the sheet S. Furthermore, the fixing device 201E presses the sheet S through the pressure roller 220a, thereby fixing the melted and mixed toner to the sheet S. At this time, the viscosity of the melted toner generates an adhesive force to the heating roller 220b on the sheet S.

[0045] Figure 2A and Figure 2B 201E. In the case where the rigidity (strength) of the sheet S is small, the adhesion force generated on the sheet S to the heating roller 220b may cause the sheet S to be rolled up due to the rotation of the heating roller 220b ( Figure 2B Therefore, a separation plate 221 ( Figure 2A ).

[0046] The image forming apparatus 201 can determine the state of the separation plate 221 according to the type and basis weight of the sheet S identified from the measurement result of the media sensor 100. For example, in the case of performing image formation on a sheet S of a type with low rigidity, the separation plate 221 is arranged so that the distal end of the separation plate 221 contacts the surface of the heating roller 220b, as shown in FIG. Figure 2A, thereby separating the sheet S from the heating roller 220b. In the case of image formation on a sheet S of a type with large rigidity, the sheet S is not rolled up by the heating roller 220b. Therefore, the separation plate 221 is arranged so that the distal end of the separation plate 221 does not contact the surface of the heating roller 220b. In this way, the surface of the heating roller 220b can be prevented from being worn by the separation plate 221.

[0047] The sheet S to which the image is fixed is delivered to the delivery space D by any one of the first delivery roller pair 225a and the second delivery roller pair 225b. The sheet S is placed on the placement portion 223 provided on the bottom surface of the delivery space D in a protruding manner. In the case where images are formed on both sides of the sheet S, the sheet S on one side of which the image is fixed is conveyed to the re-conveying path R by the reversing roller pair 222. The sheet S is conveyed to the image forming unit 201B again, and an image is formed on the other side of the reversed sheet S. The re-conveying path R allows the sheet S to be conveyed to a conveying path between the conveying roller pair 290 and the registration roller pair 240.

[0048] Image forming conditions (e.g., conveying speed at fixing, target fixing temperature, and transfer voltage at secondary transfer) differ depending on the physical properties (e.g., basis weight, rigidity, surface properties, and material, etc.) of the sheet S on which the image is to be formed. Therefore, it is necessary to set the image forming conditions in advance according to the characteristic amount of the sheet S to be used at the time of image formation.

[0049] Depending on the type of sheet S, there may be some restrictions when setting the sheet S to the sheet feed port (sheet feed box 1 or manual feed tray 5). For example, some thick paper sheets with high rigidity can only be fed from the manual feed tray 5 with a small curvature of the conveying path. It is necessary to feed the coated paper sheets with smooth surface texture and strong adhesion between sheets one by one from the manual feed tray 5 to prevent multiple sheets from being conveyed on top of each other. Paper sheets made of pulp as raw material usually have different bending rigidity in the length and width directions due to the deviation in the orientation direction (fiber orientation) of the pulp fibers caused by the manufacturing method. Therefore, the recommended orientation of the sheet in the length and width directions when setting the sheet to the sheet feed port is given, so that the bending rigidity against the bending in the conveying path becomes smaller. In addition, for a single-sided coated paper sheet obtained by coating only one side of a plain paper sheet, the orientation in the up and down direction is specified when setting to perform printing on the coated side.

[0050] There are also some types of sheets that cannot be used in the image forming apparatus 201. For example, in the case of a thick paper sheet having too high rigidity, the conveyance of the sheet may stop due to the resistance generated when the sheet is conveyed along the curved conveyance path. A thin paper sheet having too low rigidity is strongly affected by the adhesion generated between the melted toner and the heating roller 220b when passing through the fixing device 201E. Therefore, there is a possibility that the sheet cannot be separated from the heating roller 220b by the separation plate 221 and directly wraps around the heating roller 220b ( Figure 2B ). Furthermore, in the case of a synthetic paper sheet made not of pulp but of synthetic resin as a raw material, there is a possibility that the sheet is melted by heating in fixing device 201E and thereby contaminates heating roller 220b.

[0051] Therefore, in order to appropriately perform image formation, it is important to identify the type of the sheet S to be used based on the characteristic amount of the sheet S before image formation. Therefore, the media sensor 100 needs to measure the characteristic amount of the sheet S before the sheet S is conveyed to the secondary transfer unit 201D.

[0052] (Controller)

[0053] Figure 3 2 is an explanatory diagram of a controller that controls the operation of such an image forming apparatus 201. The controller 200 is, for example, an information processing device including a central processing unit (CPU). The controller 200 can be implemented by, for example, a microprocessor unit (MPU) or an application specific integrated circuit (ASIC). The controller 200 controls the above-mentioned image forming process (printing operation) performed by the image forming apparatus 201.

[0054] The controller 200 includes a control unit 400 and a memory 401. The memory 401 stores, for example, a control program for an image forming operation, initial values ​​of various setting values, and various types of data required for the image forming operation. In addition, the memory 401 has a storage area for storing a sheet type database 402. The sheet type database 402 is a database in which correspondence between sheet feature quantities, sheet types, and image forming conditions is pre-set. The control unit 400 is connected to an operation unit 502, a host device 501 as an external device, and a media sensor 100.

[0055] The host device 501 is, for example, a personal computer, an image scanner, or a fax machine. The operation unit 502 inputs, for example, instructions and settings received via the input interface to the control unit 400. The operation unit 502 outputs various types of information via the output interface under the control of the control unit 400. As described above, the operation unit 502 includes a display as an output interface, and displays various types of information on the display.

[0056] The control unit 400 acquires an instruction to start a print job from the host device 501 or the operation unit 502, and starts the print job. The control unit 400 acquires image data from the host device 501 or the image reading device 202, and performs image processing on the acquired image data. The control unit 400 performs the print job by causing the image forming unit 201B to form a toner image based on the image data subjected to the image processing and to feed the sheet S.

[0057] The media sensor 100 includes an information processing unit 160, a power supply voltage controller 170, an ultrasonic sensor 120, and an optical sensor 150. In at least one embodiment, the ultrasonic sensor 120 and the optical sensor 150 are used as a sheet material measuring unit. In addition to the ultrasonic sensor 120 and the optical sensor 150, a sheet material detection sensor 270 is also connected to the information processing unit 160. The information processing unit 160 is an information processing device, which is implemented by, for example, a CPU, an MPU, or an ASIC. The information processing unit 160 controls the measuring operation of the media sensor 100, and processes the measurement results.

[0058] The operation of the media sensor 100 is controlled by the information processing unit 160, and processing of the measurement results of each of the ultrasonic sensor 120 and the optical sensor 150 is performed by the information processing unit 160. The information processing unit 160 operates under the control of the control unit 400, and transmits the feature amount of the sheet S obtained from the measurement results of each of the ultrasonic sensor 120 and the optical sensor 150 to the control unit 400.

[0059] The control unit 400 discriminates the sheet type and sets the image forming conditions corresponding to the sheet type based on the measurement result (feature amount of the sheet) of the media sensor 100 processed by the information processing unit 160. The image forming conditions (e.g., the conveying speed at the time of fixing, the target fixing temperature, and the transfer voltage at the time of secondary transfer) differ according to the physical properties (e.g., basis weight, rigidity, surface properties, and material) of the sheet S on which the image is to be formed. Therefore, when forming an image, it is necessary to set the image forming conditions corresponding to the feature amount of the sheet S to be used in advance.

[0060] The sheet detection sensor 270 is a sensor for detecting the sheet S conveyed to the measurement position of the media sensor 100. In response to the sheet detection sensor 270 detecting the sheet S, the information processing unit 160 starts a process of measuring the characteristic amount of the sheet S by the sheet measurement unit (ultrasonic sensor 120 and optical sensor 150).

[0061] The ultrasonic sensor 120 measures the sheet S by using ultrasonic waves, and outputs an output value of a predetermined voltage value as a measurement result. The information processing unit 160 acquires the output value of the ultrasonic sensor 120, and derives the transmittance of the sheet S from the output value given when the sheet S is present and the output value given when the sheet S is not present. The information processing unit 160 detects basic weight information based on the transmittance of the sheet S. The optical sensor 150 is, for example, a contact image sensor (CIS). The information processing unit 160 stores the illuminance value of each pixel as an imaging result obtained by the optical sensor 150. The information processing unit 160 converts the stored illuminance value of each pixel into surface property information such as a difference integral value (which is the sum of differences in illuminance values ​​of adjacent pixels) and a brightness integral value (which is the sum of illuminance values ​​of each pixel).

[0062] The information processing unit 160 transmits the basic weight information and the surface property information to the control unit 400. The control unit 400 determines the sheet type and the basic weight of the sheet S based on the acquired basic weight information and the surface property information. The control unit 400 discriminates the sheet type of the sheet S based on the plurality of pieces of information stored in the sheet type database 402, and determines image forming conditions (e.g., a secondary transfer bias value, a target fixing temperature of the fixing device 201E, and a conveying speed at the time of fixing) corresponding to the sheet type and the basic weight. The control unit 400 displays the determined image forming conditions on the display of the operation unit 502. In addition, the control unit 400 controls the image forming operation based on the determined image forming conditions.

[0063] The power supply voltage controller 170 is connected to the control unit 400. The power supply voltage controller 170 controls the supply of the power supply voltage to operate the media sensor 100 based on the command signal acquired from the control unit 400. In at least one embodiment, the power supply voltage controller 170 controls the supply of the power supply voltage to the ultrasonic sensor 120.

[0064] <Structure of Media Sensor>

[0065] Figure 4 and Figure 5 Each is an explanatory view of the configuration of the media sensor 100 . Figure 4 This is a view of the media sensor 100 as viewed from a direction orthogonal to the conveying direction of the sheet S. Figure 5 This is a view of the media sensor 100 viewed from the upstream side in the conveying direction of the sheet S.

[0066] like Figure 4As shown in FIG. 1 , the media sensor 100 is arranged between the conveying roller pair 280 and the conveying roller pair 290 , and acquires the characteristic amount (basic weight information and surface property information) of the conveyed sheet S. The sheet detection sensor 270 is arranged on the upstream side of the media sensor 100 in the sheet S conveying direction (on the conveying roller pair 280 side).

[0067] like Figure 5 As shown in FIG. 1 , in the media sensor 100, the ultrasonic sensor 120 and the optical sensor 150 are arranged at the same position in the conveying direction of the sheet S, and are arranged side by side in a direction orthogonal to the conveying direction. The ultrasonic sensor 120 includes an ultrasonic transmitter 130 and an ultrasonic receiver 131. The optical sensor 150 is a CIS including a light source 1501 (e.g., LED) and a line sensor 1502. The optical sensor 150 can be configured by using a CCD image sensor or a CMOS image sensor.

[0068] The optical sensor 150 measures the illuminance value of the received light to measure the surface property of the sheet S. For this purpose, the sheet S needs to be kept at the optical focus position of the optical sensor 150. When the ultrasonic sensor 120 measures the sheet S, the measurement accuracy is improved when there is no influence caused by the shaking of the conveyed sheet S. For this purpose, the sheet S needs to be conveyed in a stable posture.

[0069] In at least one embodiment, in order to convey the sheet S in a stable posture, a sheet pressing roller 260 and a sheet pressing roller 261 are arranged between the conveying roller pair 280 and the conveying roller pair 290. The sheet pressing roller 260 and the sheet pressing roller 261 are arranged at the same position in the conveying direction of the sheet S. The sheet pressing roller 260 is arranged to face the optical sensor 150 across the conveying path. The sheet pressing rollers 260 and 261 are configured to move between a first position away from the media sensor 100 and a second position close to the media sensor 100. Figure 4 and Figure 5 , a state where the sheet pressing rollers 260 and 261 are arranged at the second position is illustrated. The sheet pressing rollers 260 and 261 are configured so that when arranged at the second position, the sheet pressing rollers 260 and 261 press the sheet S toward the media sensor 100 (optical sensor 150).

[0070] When arranged at the second position, the sheet pressing rollers 260 and 261 press against the sheet S whose conveyance has stopped. The sheet pressing rollers 260 and 261 press the sheet S against the media sensor 100. That is, the sheet pressing rollers 260 and 261 are pressing members that press the sheet S and make the sheet S abut against the media sensor 100. By making the sheet S abut against the media sensor 100, changes in position and posture are reduced. Therefore, the media sensor 100 can measure characteristic quantities of the sheet S, such as surface properties and basis weight, in a stable state. It is noted that the sheet pressing rollers 260 and 261 move to the second position and press the sheet S only when measuring the sheet S, and retract to the first position when not measuring the sheet S. Therefore, the sheet S is conveyed to the measuring position of the media sensor 100 without being hindered from entering the measuring position (ultrasonic sensor 120 and optical sensor 150).

[0071] In the case where the sheet pressing rollers 260 and 261 are arranged at the second position and the conveyance of the sheet S is not stopped, the conveyance causes the sheet S to shake, which may cause the sheet S to deflect or jam. It is important that the longitudinal direction of the line sensor 1502 is orthogonal to the conveyance direction of the sheet S. For this reason, the sheet pressing rollers 260 and 261 are pressed against the stopped sheet S, so that the characteristic amount can be stably measured. The control unit 400 restarts the conveyance of the sheet S when the posture of the sheet S is in a stable state, and at the same time instructs the information processing unit 160 to measure the characteristic amount of the sheet S by using the medium sensor 100. In response to the instruction, the information processing unit 160 starts to measure the characteristic amount of the sheet S by using the medium sensor 100.

[0072] <Measurement of Basis Weight>

[0073] like Figure 5 As shown in FIG. 1 , in the ultrasonic sensor 120, an ultrasonic transmitter 130 and an ultrasonic receiver 131 are arranged at opposite positions across the conveying path. The ultrasonic transmitter 130 is arranged on the upper block 110 side of the media sensor 100. The ultrasonic receiver 131 is arranged on the lower block 109 side of the media sensor 100. The ultrasonic sensor 120 receives the ultrasonic wave outputted from the ultrasonic transmitter 130 via the conveying path of the sheet S through the ultrasonic receiver 131. The ultrasonic receiver 131 outputs information (output value) for determining the basis weight of the sheet S based on the received ultrasonic wave.

[0074] The ultrasonic transmitter 130 and the ultrasonic receiver 131 are each formed by a piezoelectric element (also called a "piezo element") and an electrode terminal. The piezoelectric element is an element used for mutual conversion between mechanical displacement and electrical signals. The ultrasonic transmitter 130 generates ultrasonic waves through the oscillation of the piezoelectric element in response to a pulse voltage with a predetermined frequency input to the electrode terminal. The generated ultrasonic wave propagates through the air. When the ultrasonic wave reaches the sheet S, the ultrasonic wave causes the sheet S to vibrate. The ultrasonic wave generated in the ultrasonic transmitter 130 propagates to the ultrasonic receiver 131 via the sheet S. The piezoelectric element of the ultrasonic receiver 131 causes the electrode terminal to generate an output voltage corresponding to the amplitude of the received ultrasonic wave. The output voltage has a voltage value corresponding to the basis weight of the sheet S. The output voltage is transmitted to the information processing unit 160 as an output value.

[0075] The amplitude attenuation of the ultrasonic wave when the sheet S is present is greater than when the sheet S is not present. Therefore, the output value (output voltage) output from the ultrasonic receiver 131 has a different value depending on the presence or absence of the sheet S. The ratio between the output voltage given when the sheet S is not present between the ultrasonic transmitter 130 and the ultrasonic receiver 131 and the output voltage given when the sheet S is present is the transmittance. The transmittance of the ultrasonic wave varies depending on the basis weight (area density) of the sheet S. Therefore, the basis weight of the sheet S can be estimated by using a conversion formula or a conversion table between the transmittance and the basis weight. In this way, the basis weight of the sheet S is measured by the ultrasonic sensor 120.

[0076] <Measurement of surface properties>

[0077] The surface property of the sheet S is measured by using the optical sensor 150. Light emitted from the light source 1501 illuminates the sheet S at a constant angle through a light guide (not shown). The sheet S reflects the irradiated light. The light reflected by the sheet S forms an image on the light receiving surface of the line sensor 1502 via a lens (not shown). In this way, the line sensor 1502 can read the light reflected from the sheet S as an image.

[0078] In the line sensor 1502, a plurality of light receiving elements are arranged in a direction perpendicular to the conveying direction of the sheet S, so the line sensor 1502 can read an image corresponding to one line in the direction perpendicular to the conveying direction at a time. In at least one embodiment, the line sensor 1502 can read an image of 400 pixels at a time.

[0079] In at least one embodiment, a plurality of light receiving elements are arranged so that the line sensor 1502 can read an image at a resolution of 300 dpi. The image corresponding to one line read by the line sensor 1502 at one time is insufficient as the amount of information for determining the surface properties of the sheet S. This is because in the image corresponding to one line, there is a large deviation in the reading result of each reading position. For this reason, the optical sensor 150 performs a reading operation on the conveyed sheet S multiple times, and obtains the reading results of the images of multiple lines of the sheet S. By connecting the reading results of multiple lines in the conveying direction of the sheet S, it becomes possible to determine the trend of the surface properties of the sheet S of a predetermined size.

[0080] <Media sensor temperature rise>

[0081] When the image forming device 201 is activated, the image forming device 201 supplies a power supply voltage to each component, so that each component becomes ready for operation. When the image forming device 201 is activated, the power supply voltage also starts to be applied to the media sensor 100, and the media sensor 100 becomes ready for operation. The application of the power supply voltage causes the temperature of the media sensor 100 to rise. The temperature rise affects the output value (output voltage), for example, even in the case of measuring the same type of sheet, it also causes different output values ​​to be output. This phenomenon is particularly noticeable for the ultrasonic sensor 120.

[0082] Figure 6 is a graph showing the temperature characteristics of the output value of the ultrasonic sensor 120. As is clearly seen from the graph, as the duration (elapsed time) during which the power supply voltage is applied to the ultrasonic sensor 120 increases, the rate of change of the output value of the ultrasonic sensor 120 increases. In particular, for one hour after the start of application of the power supply voltage, the rate of change fluctuates greatly. When the power supply voltage is applied, the ultrasonic sensor 120 generates heat, and thus the temperature of the ultrasonic sensor 120 rises. In this way, the temperature increase of the media sensor 100 affects the measurement result, making it difficult to accurately measure the characteristic amount of the sheet S. In the case where the characteristic amount cannot be accurately measured, it is difficult to accurately distinguish the type of the sheet S, which affects the setting of appropriate image forming conditions.

[0083] To this end, in at least one embodiment, a configuration is described in which a feature amount of a sheet S is measured, the type of the sheet S is accurately discriminated, and appropriate image forming conditions are set while suppressing the influence of a temperature increase. Figure 71 is a flowchart illustrating an image forming process including a process for discriminating the type of a sheet S in at least one embodiment. The control unit 400 and the information processing unit 160 cooperate to perform the process. In at least one embodiment, in an initial state, that is, when the image forming apparatus 201 is activated, no power supply voltage is supplied to the ultrasonic sensor 120.

[0084] The control unit 400 waits until an instruction to start a print job is acquired from the operation unit 502 or the host device 501 (step S101: No). In the case where the control unit 400 acquires an instruction to start a print job (step S101: Yes), the control unit 400 determines whether an automatic detection mode of the type of sheet S is set (step S102). The setting of the automatic detection mode will be described later.

[0085] In the case where the automatic detection mode is set (step S102: Yes), the control unit 400 transmits a command signal to the power supply voltage controller 170 to instruct the power supply voltage controller 170 to supply the power supply voltage to the ultrasonic sensor 120, so that the power supply voltage is applied to the ultrasonic sensor 120 (step S103). As the power supply voltage is applied, the ultrasonic sensor 120 is activated. The control unit 400 transmits an instruction to the information processing unit 160 to cause the ultrasonic sensor 120 to perform ultrasonic measurement in a state where the sheet S is not present (step S104). The information processing unit 160 stores the measurement result (output value) of the ultrasonic sensor 120 in a state where the sheet S is not present in the internal memory.

[0086] The control unit 400 starts conveying the sheet S (step S105). The control unit 400 waits until the sheet detection sensor 270 detects the sheet S (step S106: No). In the case where the sheet detection sensor 270 detects the sheet S (step S106: Yes), the control unit 400 waits until a predetermined time period elapses while continuing the conveyance of the sheet S (step S107). The predetermined time period is the time that elapses from when the sheet detection sensor 270 detects the leading edge of the sheet S until the leading edge of the sheet S is clamped by the conveying roller pair 290. As a result of waiting for the predetermined time period, the sheet S is conveyed to the measuring position of the media sensor 100.

[0087] In the case where a predetermined period of time has passed, the control unit 400 transmits an instruction to the information processing unit 160 to perform a measurement process on the feature amount of the sheet S by using the media sensor 100. Therefore, the information processing unit 160 causes the ultrasonic sensor 120 to perform ultrasonic measurement in a state where the sheet S exists, and stores the measurement result (output value) in the internal memory (step S108). In the case where the measurement process of the ultrasonic sensor 120 is completed, the control unit 400 transmits a command signal to stop supplying the power supply voltage to the ultrasonic sensor 120 to the power supply voltage controller 170, and stops applying the power supply voltage to the ultrasonic sensor 120 (step S109). This stops the operation of the ultrasonic sensor 120. Next, the information processing unit 160 causes the optical sensor 150 to perform a measurement process on the sheet S, and stores the measurement result (illuminance value) in the internal memory (step S110).

[0088] The information processing unit 160 acquires the transmittance for the state in which the sheet S exists and the state in which the sheet S does not exist from the measurement result of the ultrasonic sensor 120 , and converts the transmittance into basis weight (step S111 ). Figure 8 is an explanatory diagram of the relationship between transmittance and basis weight. The conversion of transmittance to basis weight is performed using a conversion formula or a conversion table representing this relationship. The information processing unit 160 determines the surface property of the sheet S based on the illuminance value of the sheet S measured by the optical sensor 150, and generates surface property information representing the surface property (step S112). The surface property information includes, for example, a difference integral value and a brightness integral value. The information processing unit 160 transmits the basis weight information and the surface property information representing the basis weight obtained in this way to the control unit 400.

[0089] The control unit 400 discriminates the type of the sheet S based on the basic weight information and the surface property information acquired from the information processing unit 160 , and forms an image on the sheet S based on the image forming conditions corresponding to the type of the sheet S (step S113 ). Fig. 9 It is a classification table of sheet material types based on difference integral value and brightness integral value. Fig. 9 , the table is a matrix in which the vertical axis represents the difference integral value and the horizontal axis represents the brightness integral value, and the surface properties of the sheet are measured in advance and the sheet type is classified by machine learning. The thresholds for classifying the sheet type are a0 to a3 for the brightness integral value and b0 to b4 for the difference integral value. These thresholds are stored in the sheet type database 402 of the memory 401. The control unit 400 discriminates the sheet type by comparing the surface property information with each threshold.

[0090] Fig.10is a sheet type classification table based on basic weight. The sheet type is determined based on which basic weight range the basic weight measured by the media sensor 100 belongs to. Thresholds indicating the basic weight range are indicated by C1 to C23 and stored in the sheet type database 402 of the memory 401.

[0091] The control unit 400 determines the weight of the medium based on the basic weight information obtained from the medium sensor 100 and the surface property information and the Fig. 9 The classification table determines the sheet type in Fig.10 The control unit 400 determines the image forming conditions corresponding to the determined sheet type. Fig.11 is a classification table of sheet types, which summarizes Fig. 9 and Fig.10 Such a classification table may be stored in the sheet type database 402 of the memory 401, and the control unit 400 may determine the image forming conditions based on such a classification table.

[0092] In the case where the automatic detection mode is not set (step S102: No), the control unit 400 forms an image on the sheet S based on the image forming condition corresponding to the type of the sheet S set by the user (step S114). As described above, in the case where the automatic detection mode is set, the image forming apparatus 201 automatically discriminates the type of the sheet S, determines the image forming condition based on the discriminated result, and performs image formation. After the conveyance of the sheet S starts and before the measurement of the sheet S starts, the power supply voltage is applied to the ultrasonic sensor 120, and the application of the power supply voltage is stopped after the measurement ends. Therefore, the influence of the temperature rise on the measurement result is suppressed.

[0093] Fig.12 701 is an exemplary view of a setting screen in the automatic detection mode. The setting screen is displayed on the display of the operation unit 502. On the setting screen, the type and basis weight of the sheets contained in each sheet feeding cassette 1 and the sheets placed on the manual feed tray 5 can be set. The name of each sheet feeding cassette 1 and the manual feed tray 5 is displayed in the display area 701. The type and basis weight of the sheets contained in each sheet feeding cassette 1 and the sheets placed on the manual feed tray 5 are displayed in the display area 702. The display area 701 displays the manual feed tray 5 at the top, and displays four sheet feeding cassettes 1 (cassettes 1, 2, 3, and 4) below it.

[0094] By using the media sensor 100, the type and basis weight of the sheet fed from any sheet feeding port (manual feed tray 5 or each sheet feeding cassette 1) can be automatically discriminated. In order to use this automatic discrimination function, an automatic detection button 703 is displayed on the setting screen. When setting the automatic detection mode, the user selects (presses) the automatic detection button 703 by using the input interface of the operation unit 502. In the case where the automatic detection button 703 is pressed, the automatic detection mode is switched between an "ON" setting (i.e., automatic detection is enabled) and an "OFF" setting (i.e., automatic detection is disabled).

[0095] In the case where the control unit 400 acquires a notification indicating that the automatic detection mode is set from the operation unit 502, the control unit 400 stores the fact that the automatic detection mode is set in the memory 401. The memory 401 has, for example, a flag indicating the setting state of the automatic detection mode, and the state of the flag is changed by pressing the automatic detection button 703. The automatic detection mode setting screen may be displayed on the host device 501. In this case, the automatic detection mode is set by using an input device arranged in the host device 501.

[0096] In the image forming apparatus 201 having the above-described configuration, since the power supply voltage is applied when the ultrasonic sensor 120 measures the sheet S, it is possible to suppress the temperature rise of the ultrasonic sensor 120 during the measurement. Therefore, the influence of the temperature change on the measurement result of the ultrasonic sensor 120 (media sensor 100) is suppressed, the discrimination accuracy of the type of the sheet S is improved, and an appropriate image forming condition is set.

[0097] (Modified Example 1)

[0098] Fig.13 yes Figure 3 An exemplary diagram of a modified example of a controller of Figure 3 The difference is that the power supply voltage controller 170 controls the application of the power supply voltage to the ultrasonic receiver 131 instead of the entire ultrasonic sensor 120. The fluctuation of the measurement result (output value) of the ultrasonic sensor 120 is greatly affected by the temperature change of the ultrasonic receiver 131 that outputs the output value. Therefore, the fluctuation of the output value can be suppressed by adjusting the supply of the power supply voltage to the ultrasonic receiver 131.

[0099] Fig.14 : is a flowchart illustrating the image forming process including a process for discriminating the type of the sheet S in this case. Fig.14 Flowchart and Figure 7The flowchart of FIG. 1 is different only in that the portion to which the power supply voltage is supplied in the processing steps of step S203 and step S209 is the ultrasonic receiver 131, and the other processing steps are the same. Also in this case, the power supply voltage is applied to the ultrasonic sensor 120 only when the sheet S is measured, thereby suppressing the influence of temperature changes on the measurement result of the ultrasonic sensor 120, improving the accuracy of distinguishing the type of the sheet S, and setting an appropriate image forming condition.

[0100] <Modification Example 2>

[0101] exist Figure 7 In the process, the power supply voltage is stopped immediately after the measurement is completed. However, when the temperature of the media sensor 100 is sufficiently reduced at the start of the next measurement and the temperature does not affect the measurement result, it is not necessary to stop the power supply voltage.

[0102] Fig.15 : is a flowchart illustrating the image forming process including a process for discriminating the type of the sheet S in this case. Fig.15 The flowchart up to the measurement process of the ultrasonic sensor 120 in step S308 is the same as Figure 7 The flowchart is the same as Fig.15 In the case where the measurement process of the ultrasonic sensor 120 is completed, Figure 7 The control unit 400 performs the processing steps including the measurement of the optical sensor 150, the determination of the basis weight, the determination of the surface properties, and the image formation in the same manner as the processing steps of steps S110 to S113 (steps S309 to S312). Then, the control unit 400 transmits a command signal to stop the supply of the power supply voltage to the ultrasonic sensor 120 to the power supply voltage controller 170, and stops applying the power supply voltage to the ultrasonic sensor 120 (step S313). This stops the ultrasonic sensor 120. After stopping the ultrasonic sensor 120, the control unit 400 outputs the sheet S (printed material) on which the image has been formed to the delivery space D (step S315).

[0103] Therefore, in Modification Example 2, the supply of the power supply voltage to the ultrasonic sensor 120 is stopped before the print product is output. As long as the supply of the power supply voltage to the ultrasonic sensor 120 is stopped before the sheet S is output, the temperature of the ultrasonic sensor 120 drops enough so that the measurement result is not affected even when the type of the sheet S for the next print job needs to be immediately discriminated. Therefore, the influence of the temperature change on the measurement result of the ultrasonic sensor 120 is suppressed, the discrimination accuracy of the type of the sheet S is improved, and an appropriate image forming condition is set.

[0104] <Modification Example 3>

[0105] exist Figure 7 In the process of step S104 and step S108, in order to perform ultrasonic measurement in the process steps of step S104 and step S108, the power supply voltage is applied to the ultrasonic sensor 120 before the process step of step S104, and the application of the power supply voltage is stopped after the process step of step S108. It is sufficient to apply the power supply voltage to the ultrasonic sensor 120 at each ultrasonic process step. Fig.16 : is a flowchart illustrating the image forming process including a process for discriminating the type of the sheet S in this case. Fig.16 The flowchart of FIG. 1 is similar to the flowchart of FIG. 1 until the measurement process performed by the ultrasonic sensor 120 in the state where the sheet S is not present in step S404. Figure 7 The flowchart is the same as in .

[0106] When the measurement process of the ultrasonic sensor 120 in the state where the sheet S is not present is finished, the control unit 400 transmits a command signal to stop supplying the power supply voltage to the ultrasonic sensor 120 to the power supply voltage controller 170, and stops applying the power supply voltage to the ultrasonic sensor 120 (step S405). This stops the operation of the ultrasonic sensor 120. The control unit 400 starts to operate in the same manner as Figure 7 The sheet S is conveyed in the same manner as the processing steps of steps S105 to S107, and in a case where the sheet detection sensor 270 detects the sheet S, the control unit 400 waits until a predetermined time has elapsed (steps S406 to S408).

[0107] When the predetermined time has passed, the control unit 400 transmits a command signal to the power supply voltage controller 170 to instruct the power supply voltage controller 170 to supply the power supply voltage to the ultrasonic sensor 120, so that the power supply voltage is applied to the ultrasonic sensor 120 (step S409). Since the power supply voltage is applied, the ultrasonic sensor 120 is activated. After the activation of the ultrasonic sensor 120, the control unit 400 transmits an instruction to perform a measurement process on the feature amount of the sheet S by using the media sensor 100 to the information processing unit 160. As a result, the information processing unit 160 causes the ultrasonic sensor 120 to perform ultrasonic measurement in a state where the sheet S exists, and stores the measurement result (output value) in the internal memory (step S410).

[0108] When the measurement process of the ultrasonic sensor 120 is finished, the control unit 400 transmits a command signal to the power supply voltage controller 170 to instruct the power supply voltage controller 170 to stop supplying the power supply voltage to the ultrasonic sensor 120, and stops applying the power supply voltage to the ultrasonic sensor 120 (step S411). This stops the operation of the ultrasonic sensor 120. Then, the control unit 400 performs the same operation as that of the ultrasonic sensor 120. Figure 7The processing steps (steps S412 to S416) including the measurement of the optical sensor 150, the determination of the basis weight, the determination of the surface property, and the image formation are performed in the same manner as the processing steps of steps S110 to S114.

[0109] Therefore, in Modification Example 3, the ultrasonic sensor 120 is supplied with the power supply voltage when performing measurement. That is, the power supply voltage is applied to the ultrasonic sensor 120 before starting measurement in a state where there is no sheet S, the application of the power supply voltage is terminated after the measurement is completed, the power supply voltage is applied before starting measurement in a state where there is a sheet S, and the application of the power supply voltage is terminated after the measurement is completed. Therefore, the influence of temperature change on the measurement result of the ultrasonic sensor 120 is suppressed, the discrimination accuracy of the type of the sheet S is improved, and an appropriate image forming condition is set.

[0110] The case corresponding to the temperature change of the ultrasonic sensor 120 has been described above, but the same process can be performed on all sensors of the media sensor 100. This at least one embodiment is effective for any case where heat generation caused by application of a power supply voltage affects the measurement result of the sensor. In addition, as with Modification Example 1, Modification Examples 2 and 3 can have a configuration for controlling the application of a power supply voltage to the ultrasonic receiver 131.

[0111] In the above description, the media sensor 100 is arranged in the image forming apparatus 201, but as long as the media sensor 100 is arranged on the upstream side of the secondary transfer unit 201D in the sheet conveying direction, the media sensor 100 may be arranged outside the image forming apparatus 201. In addition, the processing of the information processing unit 160 in the media sensor 100 may be performed by the control unit 400. In contrast, the processing performed by the control unit 400 may be performed by the information processing unit 160. In this case, the sheet type database 402 may be stored in a memory that can be accessed from the information processing unit 160. In any case, it is sufficient that the above-mentioned processing is performed by the control unit 400 in cooperation with the information processing unit 160.

[0112] In addition, the above-mentioned image forming apparatus 201 determines control parameters such as image forming conditions by detecting the type and basis weight of the sheet S according to the characteristic amount of the sheet S measured by the media sensor 100. However, the control parameters may be determined directly according to the characteristic amount. The media sensor 100 may be a device that measures the physical properties of another sheet.

[0113] The above-described media sensor 100 is an example and is not limited to a configuration including the optical sensor 150 and the ultrasonic sensor 120 . The media sensor 100 may include another sensor that can measure a characteristic amount of the sheet S. In addition, the media sensor 100 may include any one of the optical sensor 150 and the ultrasonic sensor 120 .

[0114] Furthermore, in the above description, the configuration of the image forming device 201 has been described, but the present disclosure can be applied to any device including a sheet detection device (including the media sensor 100 and the controller 200). For example, such a sheet detection device can be used in an image reading device that reads an image printed on a sheet while conveying the sheet. The image reading device includes an automatic document feeder (ADF). By incorporating the sheet detection device into the ADF, it becomes possible to stably read an image and convey the sheet.

[0115] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

[0116] This application claims the benefit of Japanese Patent Application No. 2023-149055, filed on September 14, 2023, which is hereby incorporated by reference in its entirety.

Claims

1. A sheet material detection device, comprising: a measuring component configured to measure the sheet; and a power supply voltage control section configured to control the supply of the power supply voltage to the measuring section, wherein the power supply voltage control section is configured to start supplying the power supply voltage to the measuring section when receiving a notification indicating that a mode for performing sheet material measurement is set.

2. The sheet material detection device according to claim 1, further comprising: a conveying member configured to convey a sheet; and a sheet detection sensor section configured to detect a sheet conveyed by the conveying section, wherein the power supply voltage control section is configured to start supplying the power supply voltage to the measuring section in response to the sheet detection sensor section detecting the sheet, and The measuring component is configured to measure the sheet transported by the transport component. 3 . The sheet material detection apparatus according to claim 2 , wherein the power supply voltage control section is configured to stop supplying the power supply voltage to the measuring section when the measurement of the sheet material by the measuring section is finished.

4. The sheet material detection apparatus according to claim 1, further comprising a conveying member configured to convey the sheet material, wherein the measuring means is configured to perform the first measurement in a state where the sheet is not transported by the transport means, and to perform the second measurement in a state where the sheet is transported by the transport means, and The power supply voltage control component is configured to supply the power supply voltage to the measurement component before the first measurement starts, and to stop supplying the power supply voltage to the measurement component after the second measurement ends.

5. A sheet material detection device according to claim 4, wherein the power supply voltage control component is configured to supply the power supply voltage to the measuring component before the start of the first measurement, stop supplying the power supply voltage to the measuring component after the first measurement is completed, supply the power supply voltage to the measuring component before the start of the second measurement, and stop supplying the power supply voltage to the measuring component after the second measurement is completed.

6. The sheet material detection apparatus according to claim 5, further comprising a sheet material detection sensor section configured to detect the sheet material conveyed by the conveying section, The power supply voltage control section is configured to supply the power supply voltage to the measuring section before the second measurement starts in response to the sheet detection sensor section detecting the sheet.

7. The sheet material detecting apparatus according to claim 4 or 5, wherein the measuring means is an ultrasonic sensor means.

8. The sheet material detection device according to claim 7, The ultrasonic sensor components include: An ultrasonic transmitting component configured to output ultrasonic waves; and an ultrasonic wave receiving part configured to receive the ultrasonic wave outputted from the ultrasonic wave transmitting part, and output an output value corresponding to the received ultrasonic wave, and The power supply voltage control component is configured to control the power supply voltage supplied to the ultrasonic receiving component.

9. A sheet material detection device, comprising: a conveying member configured to convey a sheet; a measuring part configured to measure the sheet conveyed by the conveying part; a sheet detection sensor section configured to detect a sheet conveyed by the conveying section; and a power supply voltage control section configured to control the supply of the power supply voltage to the measuring section, The power supply voltage control section is configured to start supplying the power supply voltage to the measuring section when the sheet detection sensor section detects the sheet.

10. A sheet material detection device, comprising: a measuring component configured to measure the sheet; and a power supply voltage control section configured to control the supply of the power supply voltage to the measuring section, The power supply voltage control component is configured to start supplying the power supply voltage to the measuring component when receiving an instruction to start the operation.

11. An image forming device, comprising: Sheet material detection components, including: a measuring component configured to measure the sheet; and a power supply voltage control section configured to control the supply of the power supply voltage to the measuring section, An image forming section configured to form an image on the sheet by using an image forming condition based on a result of measurement of the sheet by the measuring section; and a delivery space to which the sheet having the image formed thereon is to be delivered, wherein the power supply voltage control section is configured to start supplying the power supply voltage to the measuring section when receiving a notification indicating that a mode for performing sheet material measurement is set. 12 . The image forming apparatus according to claim 11 , wherein the power supply voltage control section is configured to stop supplying the power supply voltage to the measuring section before the sheet having the image formed thereon is delivered to the delivery space. 13 . The image forming apparatus according to claim 11 , wherein the power supply voltage control section is configured to supply the power supply voltage to the measuring section when an instruction to start a print job is acquired.

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