Media detection device, image forming system, and program

Abstract

To enable more accurate detection of moisture information corresponding to the moisture content or moisture percentage of paper. [Solution] The media detection device (detection device 20) is a media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper, and comprises a moisture sensor 23 having a light-emitting unit (second light-emitting unit 232) that emits light and a light-receiving unit 233 that receives light reflected by the paper or transmitted through the paper, and a temperature control unit (detection control unit 21) that controls the temperature of the light-emitting unit so that the wavelength of the light emitted from the light-emitting unit becomes a predetermined wavelength.

Description

Technical Field

[0001] The present invention relates to a media detection device, an image forming system, and a program.

Background Art

[0002] Conventionally known image forming apparatuses have installed a media sensor in the middle of the paper conveyance path and detect the characteristic values of the paper being conveyed along the conveyance path using the media sensor. Next, the image forming apparatus determines the image forming conditions according to the characteristic values of the paper detected by the media sensor and forms an image on the paper.

[0003] When measuring the moisture content of paper using a moisture sensor as a media sensor, the measurement results may change even though the paper is in the same state. This is because the wavelength of the light emitted by the light emitting part (such as an LED) of the moisture sensor changes due to a temperature rise caused by the self-heating of the light emitting part itself, etc., and the moisture sensitivity changes accordingly. Due to such a phenomenon, there is a problem that an error occurs in the moisture content of the paper detected by the moisture sensor with respect to the original moisture content of the paper.

[0004] For example, Patent Document 1 describes correcting the moisture content of the paper detected by the moisture sensor based on the temperature of the light emitting part and correction values preset for each representative paper type such as plain paper and thick paper in response to the above phenomenon.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the characteristics of the change in light absorption rate due to moisture in the paper vary depending on the paper's composition, thickness, color, surface shape, etc. Therefore, when correcting the moisture content of the paper detected by the moisture sensor based on correction values ​​corresponding to typical paper types, as in the invention described in Patent Document 1, there is a problem in that it is difficult to perform sufficient correction for all paper types.

[0007] The object of the present invention is to provide a media detection device, an image forming system, and a program that can more accurately detect moisture information corresponding to the moisture content or moisture ratio of paper. [Means for solving the problem]

[0008] To solve the above problem, the media detection device described in claim 1 is A media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper, A moisture sensor having a light-emitting unit that emits light and a light-receiving unit that receives light reflected by the paper or transmitted through the paper, A temperature control unit controls the temperature of the light-emitting unit so that the wavelength of the light emitted from the light-emitting unit becomes a predetermined wavelength. It is equipped with.

[0009] The invention described in claim 2 is a media detection device according to claim 1, The temperature control unit controls the temperature of the light-emitting unit while detecting moisture information, based on the measurement results from a temperature sensor located near the light-emitting unit.

[0010] The invention described in claim 3 is a media detection device according to claim 1, The system includes at least one of a heating unit for heating the light-emitting unit and a cooling unit for cooling the light-emitting unit.

[0011] The invention described in claim 4 is a media detection device described in claim 3, The temperature control unit heats the light-emitting part by passing an electric current through a resistive element located near the light-emitting part of the heating unit.

[0012] The invention described in claim 5 is a media detection device described in claim 3, The temperature control unit cools the light-emitting unit using at least one of the fan motor and Peltier element of the cooling unit.

[0013] The invention described in claim 6 is a media detection device according to claim 1, The light-emitting section comprises an LED (Light Emitting Diode) element or a laser diode element.

[0014] The invention described in claim 7 is a media detection device described in claim 1, The temperature control unit controls the temperature of the light-emitting unit based on temperature characteristic information that shows the correspondence between the wavelength of light and the temperature of the light-emitting unit for each light-emitting element of the light-emitting unit.

[0015] The invention described in claim 8 is a media detection device described in claim 7, It includes a storage unit for storing the aforementioned temperature characteristic information.

[0016] The invention described in claim 9 is a media detection device according to claim 1, The temperature control unit controls the temperature of the light-emitting unit before detecting the moisture information.

[0017] The invention described in claim 10 is a media detection device described in claim 9, The temperature control unit controls the temperature of the light-emitting unit by passing an electric current through the light-emitting element of the light-emitting unit when no moisture information is detected.

[0018] The invention described in claim 11 is a media detection device described in claim 9, When the moisture information is not detected, the temperature control unit controls the temperature of the light emitting unit by changing the duty ratio of the current flowing through the light emitting element of the light emitting unit.

[0019] The invention according to claim 12 is the media detection device according to claim 9, Based on the measurement result by the temperature sensor arranged in the vicinity of the light emitting unit or the measurement result of the ambient temperature, the temperature control unit controls the temperature of the light emitting unit during the detection of the moisture information.

[0020] The image forming system according to claim 13 is The media detection device according to any one of claims 1 to 12, An image forming unit capable of forming an image on the paper, and comprises.

[0021] The program according to claim 14 is A media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper, A computer of a media detection device including a moisture sensor having a light emitting unit that irradiates light and a light receiving unit that receives the light reflected or transmitted through the paper by the light, is made to function as a temperature control unit that controls the temperature of the light emitting unit so that the wavelength of the light irradiated from the light emitting unit becomes a predetermined wavelength.

Effect of the Invention

[0022] According to the present invention, moisture information corresponding to the moisture content or moisture ratio of paper can be detected more accurately.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram showing a schematic configuration of an image forming system according to this embodiment. [Figure 2] It is a block diagram showing a main functional configuration of the image forming system according to this embodiment. [Figure 3] It is a diagram showing a schematic configuration of a moisture sensor. [Figure 4] This figure shows an example of the arrangement of the moisture sensor and heating unit. [Figure 5] This figure shows an example of the arrangement of the moisture sensor and heating unit. [Figure 6] This figure shows an example of the arrangement of the moisture sensor and heating unit. [Figure 7] This figure shows an example of temperature characteristic information. [Figure 8] This is a flowchart showing the flow of temperature control processing performed by the image forming system. [Figure 9] This flowchart shows the temperature control process flow for the modified example. [Modes for carrying out the invention]

[0024] Hereinafter, embodiments of the image forming system of the present invention will be described with reference to the drawings. In the embodiments of the present invention, the image forming apparatus included in the image forming system will be described using a system color image forming apparatus as an example. However, the present invention is not limited thereto, and can also be applied to, for example, a monochrome image forming apparatus.

[0025] [1. Configuration of the image forming system] Figure 1 is a diagram showing the schematic configuration of the image forming system 100 according to this embodiment. Figure 2 is a block diagram showing the main functional configuration of the image forming system 100.

[0026] The image forming system 100 according to this embodiment includes a paper feeder 10, a detection device 20 which is a media detection device, and an image forming apparatus 30. In the image forming system 100, the paper feeder 10, detection device 20, and image forming apparatus 30 are arranged in the order of upstream side along the paper transport direction.

[0027] (1-1. Configuration of the paper feed device) The paper feeding device 10 includes a paper feeding control unit 11, a transport unit 12, a paper feeding unit 13, and the like. The paper feed control unit 11 is connected to the transport unit 12 and the paper feed unit 13 via the bus 14.

[0028] The paper feed control unit 11 includes a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU of the paper feed control unit 11 reads the program stored in ROM, loads it into RAM, and then controls each part of the paper feed device 10 according to the loaded program. For example, the paper feed control unit 11 transports paper from the paper feed tray of one of the paper feed units 13 to the detection device 20, depending on the job.

[0029] The transport unit 12 transports paper via a transport path connecting the paper feeding unit 13 to the detection device 20. The paper feeding unit 13 has paper trays for storing paper according to predetermined paper types, sizes, etc.

[0030] (1-2. Configuration of the detection device) The detection device 20 is located upstream of the image forming apparatus 30 in the paper transport direction and detects the paper transported from the paper feed device 10. The detection device 20 includes a detection control unit 21, a transport unit 22, a moisture sensor 23, a heating unit 25, a cooling unit 26, and a storage unit 27. The detection control unit 21 is connected to the transport unit 22, moisture sensor 23, heating unit 25, cooling unit 26, and storage unit 27 via the bus 28. The detection device 20 may include at least one of the heating unit 25 and the cooling unit 26.

[0031] The detection control unit 21 includes a CPU, ROM, and RAM. The CPU of the detection control unit 21 reads the program stored in ROM, loads it into RAM, and then controls each part of the detection device 20 according to the loaded program. For example, the detection control unit 21 causes the moisture sensor 23 to detect the paper being transported from the paper feed device 10. Next, the detection control unit 21 transports the detected paper to the image forming apparatus 30 using the transport unit 22.

[0032] The transport unit 22 is composed of multiple roller pairs and transports the paper transported from the paper feed device 10 to the moisture sensor 23. Next, the transport unit 22 transports the paper detected by the moisture sensor 23 to the image forming apparatus 30.

[0033] Figure 3 is a schematic diagram showing the configuration of the moisture sensor 23. As shown in Figure 3, the moisture sensor 23 includes a first light-emitting unit 231, a second light-emitting unit 232, a light-receiving unit 233, lenses 234, 235, and the like. The first light-emitting unit 231 and the second light-emitting unit 232 are light-emitting units that emit light toward the paper.

[0034] The first light-emitting unit 231 includes an LED (Light Emitting Diode) element or a laser diode element as a light-emitting element. The first light-emitting unit 231 emits a first near-infrared light (reference light) in a specific wavelength band toward the paper P. The wavelength of the first near-infrared light is, for example, 1300 nm. The first near-infrared light is light whose absorption rate in paper P when reflected by paper P is independent of the moisture content of paper P. The light-receiving unit 233 receives the first near-infrared light emitted from the first light-emitting unit 231 and reflected from the paper P via the lens 234, through the lens 235. Next, the light-receiving unit 233 outputs information of the first received light amount, which is the amount of the reflected first near-infrared light, to the detection control unit 21. Specific examples of the light-receiving unit 233 include a PD (Photo Diode), a CCD (Charge-Coupled Device), or a CMOS image sensor (Complementary metal-oxide-semiconductor).

[0035] The second light-emitting section 232 includes an LED element or a laser diode element as a light-emitting element. The second light-emitting unit 232 emits a second near-infrared light in a specific wavelength band toward the paper P. The wavelength of the second near-infrared light is, for example, 1450 nm. The second near-infrared light is light whose absorption rate in paper P varies depending on the moisture content of paper P when reflected by paper P. The light receiving unit 233 receives the second near-infrared light emitted from the second light emitting unit 232 and reflected from the paper P via the lens 234, through the lens 235. Next, the light receiving unit 233 outputs information on the second received amount, which is the amount of the reflected second near-infrared light received, to the detection control unit 21.

[0036] In other words, the first light-emitting unit 231 and the second light-emitting unit 232 emit light of different wavelengths that are absorbed by the moisture in the paper. The second near-infrared light emitted by the second light-emitting unit 232 is light with a wavelength that is more absorbed by moisture in the paper than the first near-infrared light (reference light) emitted by the first light-emitting unit 231.

[0037] The detection control unit 21 determines the moisture content of the paper based on the ratio of the first light-receiving amount to the second light-receiving amount. This ratio of the first light-receiving amount to the second light-receiving amount is the ratio of the output of the light-receiving unit 233 to the first near-infrared light and the second near-infrared light. The higher the moisture content of the paper, the greater the absorption of second-order near-infrared light, resulting in a lower second-order light reception. Therefore, based on a relational formula or table showing the relationship between the paper's moisture content and the ratio of the first and second light receptions, the ratio of the first and second light receptions can be correlated with the paper's moisture content, and the paper's moisture content can be calculated from this ratio.

[0038] The detection control unit 21 may determine the moisture content of the paper based on the ratio of the first light received amount to the second light received amount. The detection control unit 21 may determine an index indicating the moisture content or moisture ratio of the paper based on the ratio of the first light received amount to the second light received amount. Moisture information corresponding to the moisture content or moisture percentage of paper includes the moisture content of the paper, the moisture percentage of the paper, and an index indicating the moisture content or moisture percentage of the paper.

[0039] The heating unit 25 includes a heat source resistance element 251 located near the light-emitting unit, and heats the light-emitting unit by passing an electric current through the heat source resistance element 251.

[0040] The cooling unit 26 includes at least one of a fan motor and a Peltier element, and the light-emitting unit is cooled by at least one of the fan motor and the Peltier element.

[0041] Figure 4 shows an example of the arrangement of each component constituting the moisture sensor 23 and the heat source resistance element 251. The moisture sensor 23 includes an LED case 236 that houses a first light-emitting unit 231 and a second light-emitting unit 232. The LED case 236 is mounted on the printed circuit board 238. It is preferable to use a metal substrate with excellent thermal conductivity as the printed circuit board 238, but a general glass epoxy substrate that utilizes the thermal conductivity of the copper pattern may also be used.

[0042] The moisture sensor 23 includes a temperature sensor 237, such as a thermistor, mounted on the printed circuit board 238 in the vicinity of the first light-emitting unit 231 and the second light-emitting unit 232. The temperature sensor 237 detects the temperature near the first light-emitting unit 231 and the second light-emitting unit 232, and outputs the detection result to the detection control unit 21.

[0043] The heat source resistance element 251 is mounted on the printed circuit board 238 near the first light-emitting section 231 and the second light-emitting section 232, on the opposite side of the temperature sensor 237, with the LED case 236 in between.

[0044] At least one of the fan motor and Peltier element of the cooling unit 26 is provided on the printed circuit board 238 on the side opposite to the side on which the LED case 236 is mounted.

[0045] Figure 5 shows another example of the arrangement of the components constituting the moisture sensor 23 and the heat source resistance element 251. In the example shown in Figure 5, the LED case 236 mounted on the printed circuit board 238 houses the first light-emitting unit 231, the second light-emitting unit 232, the temperature sensor 237, and the heat source resistance element 251. The heat source resistance element 251 is positioned on the opposite side of the temperature sensor 237, with the first light-emitting unit 231 and the second light-emitting unit 232 in between.

[0046] As shown in Figure 6, in order to improve heat conduction between the first light-emitting unit 231, the second light-emitting unit 232, the temperature sensor 237, and the heat source resistance element 251, the first light-emitting unit 231, the second light-emitting unit 232, the temperature sensor 237, and the heat source resistance element 251 may be mounted on the soldering terminal 239 for the heat sink. The LED case 236 is equipped with a window 236a, and the light emitted from the first light-emitting unit 231 and the second light-emitting unit 232 passes through the window 236a and is projected onto the paper. The first light-emitting unit 231 may be connected to a soldering terminal 239 for a heat sink by a bonding wire 240.

[0047] The memory unit 27 is a storage device such as a semiconductor memory like DRAM (Dynamic Random Access Memory) or an HDD (Hard Disk Drive). The memory unit 27 stores temperature characteristic information used in the temperature control process described later. Figure 7 shows an example of temperature characteristic information. The temperature characteristic information shows the correspondence between the wavelength λ of the second near-infrared light emitted by the second light-emitting unit 232 and the temperature T of the light-emitting element of the second light-emitting unit 232 for each light-emitting element of the second light-emitting unit 232. The temperature characteristic information may also be a relational expression showing the correspondence between the wavelength of the second near-infrared light emitted by the second light-emitting unit 232 and the temperature of the light-emitting element of the second light-emitting unit 232 for each light-emitting element of the second light-emitting unit 232.

[0048] (1-3. Configuration of the image forming apparatus) The image forming apparatus 30 forms a color image by electrophotography based on image data obtained by reading an image from a document, or on job image data received from an external device (not shown). The image forming apparatus 30 includes a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, an interface 35, a scanner 36, an image processing unit 37, an image forming unit 38, an image fixing unit 39, a transport unit 40, and the like. The control unit 31 is connected via the bus 41 to the storage unit 32, the operation unit 33, the display unit 34, the interface 35, the scanner 36, the image processing unit 37, the image forming unit 38, the image fixing unit 39, and the transport unit 40.

[0049] The control unit 31 includes a CPU, ROM, and RAM. The CPU of the control unit 31 reads the control program stored in ROM, loads it into RAM, and then comprehensively controls each part of the image forming apparatus 30 according to the loaded program. For example, the control unit 31 causes the image processing unit 37 to perform predetermined image processing on the image data and store it in the storage unit 32. Next, the control unit 31 causes the transport unit 40 to transport the paper and causes the image forming unit 38 to form an image on the paper based on the image data stored in the storage unit 32.

[0050] The memory unit 32 is a storage device such as a semiconductor memory like DRAM or an HDD. The memory unit 32 stores image data acquired by the scanner 36, image data input from an external source via the interface 35, etc. The RAM provided by the control unit 31 may also store this image data, etc.

[0051] The operation unit 33 includes input devices such as operation keys and a touch panel superimposed on the screen of the display unit 34. The operation unit 33 converts input operations to these input devices into operation signals and outputs them to the control unit 31.

[0052] The display unit 34 is equipped with a display device such as an LCD (Liquid Crystal Display) and displays the status of the image forming system 100, an operation screen showing the content of input operations to the touch panel, and so on.

[0053] Interface 35 transmits and receives data with an external computer, other image forming apparatus, etc. Interface 35 may include, for example, one of various serial interfaces.

[0054] The scanner 36 reads the image formed on the paper and outputs the reading result to the control unit 31. Based on the reading result from the scanner 36, the control unit 31 generates image data including monochrome image data for each color component of R (red), G (green), and B (blue), and stores it in the storage unit 32.

[0055] The image processing unit 37 includes, for example, a rasterization processing unit, a color conversion unit, a gradation correction unit, a halftone processing unit, and the like. The image processing unit 37 performs various image processing on the image data stored in the storage unit 32 and stores it back in the storage unit 32.

[0056] The image forming unit 38 forms an image on the paper based on the image data stored in the storage unit 32. The image forming unit 38 includes four sets of exposure units 381 corresponding to the color components C (cyan), M (magenta), Y (yellow), and K (black), a photosensitive drum 382, ​​a developing unit 383, a transfer unit 384, a secondary transfer roller 385, and the like.

[0057] The exposure unit 381 is equipped with an LD (Laser Diode) and drives the LD based on image data to irradiate the charged photoreceptor drum 382 with laser light, exposing it and forming an electrostatic latent image on the photoreceptor drum 382. The developing unit 383 supplies toner (colorant) of a predetermined color (one of C, M, Y, and K) onto the exposed photoreceptor drum 382 using a charged developing roller to develop the electrostatic latent image formed on the photoreceptor drum 382.

[0058] Images (monochromatic images) formed on four photoreceptor drums 382 corresponding to C, M, Y, and K toners, respectively, are sequentially transferred from each photoreceptor drum 382 onto a transfer body 384. This forms a color image on the transfer body 384 with C, M, Y, and K as color components. The transfer body 384 is an endless belt wound around multiple transfer body transport rollers and rotates in accordance with the rotation of each transfer body transport roller.

[0059] The secondary transfer roller 385 transfers the color image on the transfer body 384 onto the paper fed from the paper feed device 10. Specifically, the pair of secondary transfer rollers 385 press against each other to form a transfer nip, which grips the paper and the transfer body 384. Next, a predetermined transfer voltage is applied to the secondary transfer roller 385, causing the toner forming the color image on the transfer body 384 to be attracted to the paper and transferred to the paper.

[0060] The image fixing unit 39 is equipped with a fixing roller and a pressure roller, and performs a fixing process to fix the toner to the paper by heating and pressurizing the paper to which the toner has been transferred.

[0061] The transport unit 40 is equipped with multiple paper transport rollers that transport paper by rotating while holding the paper, and transports the paper along a predetermined transport path. The transport unit 40 includes a reversal mechanism 401 that reverses the front and back sides of the paper that has been fixed by the image fixing unit 39 and transports it to the secondary transfer roller 385. When an image is to be formed on both sides of the paper, the transport unit 40 reverses the front and back sides of the paper using the reversal mechanism 401 and discharges the paper after an image has been formed on both sides. On the other hand, when an image is to be formed on only one side of the paper, the transport unit 40 discharges the paper with an image formed on one side without reversing the front and back sides of the paper using the reversal mechanism 401.

[0062] In this embodiment, the control unit 31 of the image forming apparatus 30 comprehensively controls the entire image forming system 100, but this is not limited to this configuration. The detection control unit 21 of the detection device 20 may also comprehensively control the entire image forming system 100.

[0063] [2. Operation of the Image Forming System] Next, the operation of the image forming system 100 will be described. Figure 8 is a flowchart showing the flow of temperature control processing performed by the detection control unit 21 while the detection device 20 is detecting the moisture content of the paper using the moisture sensor 23. The CPU of the detection control unit 21 performs temperature control processing in cooperation with the program stored in ROM.

[0064] The light emitted from the first light-emitting unit 231 exhibits relatively little change in moisture sensitivity with changes in the wavelength of light. Therefore, the detection control unit 21 controls the temperature of the light-emitting unit by performing temperature control processing so that the wavelength of the light emitted from the second light-emitting unit 232 becomes the target wavelength. The detection control unit 21 functions as a temperature control unit.

[0065] (Temperature control processing) The detection control unit 21 obtains the temperature near the light-emitting part from the temperature sensor 237 (step S1). Next, the detection control unit 21 calculates the difference between the temperature near the light-emitting unit acquired in step S1 and the temperature corresponding to the target wavelength (for example, 1450 nm) of the light emitted by the second light-emitting unit 232, based on the temperature characteristic information stored in the memory unit 27 (step S2). Next, the detection control unit 21 calculates an adjustment value for the current to be supplied to the heating unit 25 or cooling unit 26 in order to correct the difference calculated in step S2 (step S3).

[0066] Next, the detection control unit 21 controls the heating unit 25 or the cooling unit 26 based on the adjustment value calculated in step S3 (step S4), and terminates the temperature control process. In step S4, the detection control unit 21 heats the light-emitting unit by passing a current corresponding to the adjustment value through the heat source resistance element 251 of the heating unit 25, thereby raising the temperature of the light-emitting unit to a temperature corresponding to the target wavelength of light emitted by the second light-emitting unit 232. Alternatively, the detection control unit 21 cools the light-emitting unit by supplying a current corresponding to the adjustment value to at least one of the fan motor and Peltier element of the cooling unit 26, thereby bringing the temperature of the light-emitting unit to a temperature corresponding to the target wavelength of light emitted by the second light-emitting unit 232.

[0067] [3. Variant] Next, modified examples of the present invention will be described. In these modified examples, the same reference numerals are used for components similar to those in the above embodiments, and their descriptions are omitted. Figure 9 is a flowchart showing the flow of the temperature control process in this modified example. The detection control unit 21 executes the temperature control process for the modified example at a time before the detection device 20 detects the moisture information of the paper using the moisture sensor 23, and before the detection device 20 detects the moisture information of the paper using the moisture sensor 23.

[0068] (Temperature control process for modified specimens) The detection control unit 21 executes steps S11 and S12, which are the same as steps S1 and S2 of the temperature control process in the above embodiment. Next, the detection control unit 21 calculates an adjustment value for the current flowing through the light-emitting elements of the first light-emitting unit 231 and the second light-emitting unit 232 in order to correct the difference calculated in step S12 (step S13). Next, the detection control unit 21 adjusts the current flowing through the light-emitting elements of the first light-emitting unit 231 and the second light-emitting unit 232 based on the adjustment value calculated in step S13 (step S14), and terminates the temperature control process for the modified example. As a result, the detection control unit 21 heats the light-emitting units to bring their temperature to a temperature corresponding to the target wavelength of light emitted by the second light-emitting unit 232. In step S14, the detection control unit 21 may adjust the duty cycle of the current flowing through the light-emitting elements of the first light-emitting unit 231 and the second light-emitting unit 232 based on the adjustment value calculated in step S13.

[0069] The present invention has been described above based on the above embodiments, but the descriptions in the above embodiments are merely examples of the image forming system according to the present invention and are not limited thereto. For example, if the image forming apparatus 30 is equipped with a detection unit that detects the temperature inside the image forming apparatus 30 (ambient temperature), the detection control unit 21 may acquire the detection result from the detection unit from the image forming apparatus 30 and, based on the detection result from the detection unit, control the temperature of the light-emitting unit while the moisture sensor 23 is detecting the moisture information of the paper.

[0070] In the above embodiment, the light receiving unit 233 receives light emitted from the first light-emitting unit 231 and the second light-emitting unit 232 and reflected by the paper P, but it is not limited to this. The light receiving unit 233 may be configured to receive light emitted from the first light-emitting unit 231 and the second light-emitting unit 232 and transmitted through the paper P.

[0071] [4. Effects] As described above, the media detection device (detection device 20) of this embodiment is a media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper. The media detection device of this embodiment includes a moisture sensor 23 having a light-emitting unit (second light-emitting unit 232) that emits light and a light-receiving unit 233 that receives light that has been reflected by or transmitted through the paper. The media detection device of this embodiment includes a temperature control unit (detection control unit 21) that controls the temperature of the light-emitting unit so that the wavelength of the light emitted from the light-emitting unit becomes a predetermined wavelength. Therefore, since changes in moisture sensitivity due to changes in the wavelength of light emitted by the light-emitting part can be suppressed, errors in the moisture content of the paper detected by the moisture sensor compared to the actual moisture content of the paper can be suppressed. This allows for more accurate detection of moisture information corresponding to the moisture content or moisture percentage of the paper.

[0072] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) while moisture information is being detected, based on the measurement results from a temperature sensor 237 located near the light-emitting unit (second light-emitting unit 232). Therefore, the temperature of the light-emitting part can be appropriately controlled based on the measurement results from the temperature sensor 237 located near the light-emitting part.

[0073] The media detection device (detection device 20) of this embodiment includes at least one of a heating unit 25 for heating the light-emitting unit (second light-emitting unit 232) and a cooling unit 26 for cooling the light-emitting unit. Therefore, the temperature of the light-emitting section can be easily controlled by controlling at least one of the heating section 25 and the cooling section 26.

[0074] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) heats the light-emitting part (second light-emitting part 232) of the heating unit 25 by passing an electric current through a resistive element (heat source resistive element 251) located near the light-emitting part of the heating unit 25. Therefore, the temperature of the light-emitting part can be easily controlled by passing an electric current through the heat source resistance element 251.

[0075] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) cools the light-emitting unit (second light-emitting unit 232) with at least one of the fan motor and Peltier element of the cooling unit 26. Therefore, the temperature of the light-emitting section can be easily controlled by at least one of the fan motor and the Peltier element.

[0076] In the media detection device (detection device 20) of this embodiment, the light-emitting unit (second light-emitting unit 232) includes an LED element or a laser diode element. Therefore, even when the light-emitting part generates its own heat, controlling the temperature of the light-emitting part allows for more accurate detection of moisture information corresponding to the moisture content or moisture ratio of the paper.

[0077] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) based on temperature characteristic information that shows the correspondence between the wavelength of light emitted from the second light-emitting unit 232 and the temperature of the light-emitting unit for each light-emitting element of the second light-emitting unit 232. Therefore, based on temperature characteristic information, adjustment values ​​for controlling the temperature of the light-emitting section can be easily calculated.

[0078] The media detection device (detection device 20) of this embodiment includes a storage unit 27 for storing temperature characteristic information. Therefore, temperature characteristic information can be easily obtained from the storage unit 27.

[0079] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) before detecting moisture information. Therefore, by detecting moisture information when the wavelength of light emitted from the light-emitting unit is a predetermined wavelength (target wavelength), moisture information can be detected with greater accuracy.

[0080] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) by passing an electric current through the light-emitting element of the light-emitting unit when moisture information is not detected. Therefore, the temperature of the light-emitting part can be easily controlled by passing an electric current through the light-emitting element of the light-emitting part.

[0081] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) by changing the duty cycle of the current flowing through the light-emitting element. Therefore, the temperature of the light-emitting part can be easily controlled by changing the duty cycle of the current flowing through the light-emitting element of the light-emitting part.

[0082] In the media detection device (detection device 20) of this embodiment, the temperature control unit (detection control unit 21) controls the temperature of the light-emitting unit (second light-emitting unit 232) during moisture information detection based on the measurement result from the temperature sensor 237 located near the light-emitting unit (second light-emitting unit 232) or the measurement result of the ambient temperature. Therefore, the temperature of the light-emitting part can be appropriately controlled based on the measurement results from the temperature sensor 237 located near the light-emitting part or the measurement results of the ambient temperature.

[0083] The image forming system 100 of this embodiment includes a media detection device (detection device 20) and an image forming unit 38 capable of forming an image on paper. This allows for image formation based on moisture information accurately detected by the detection device 20.

[0084] The above-described embodiments are examples of the media detection device, image forming system, and program according to the present invention, and are not limited thereto. The detailed configuration and operation of each part constituting the device can also be modified as appropriate without departing from the spirit of the present invention. For example, the above embodiment describes a case where the detection control unit 21 is a temperature control unit, but it is not limited to this. The control unit 31 of the image forming apparatus 30 may also function as a temperature control unit.

[0085] In the above embodiment, the media detection device was exemplified as being applicable to an image forming apparatus 30 using an electrophotographic printing method, but it is not limited to this and can also be applied to inkjet image forming apparatuses and other image forming apparatuses using other printing methods. [Explanation of Symbols]

[0086] 100 Image Forming Systems 10 Paper feeder 11 Paper feed control unit 12 Conveying section 13 Paper feed section 14 bus 20. Detection device (media detection device) 21. Detection and Control Unit (Temperature Control Unit) 22 Conveying section 23 Moisture sensor 231 First light-emitting section (light-emitting section) 232 Second light-emitting section (light-emitting section) 233 Light receiving part 234, 235 lenses 236 LED Case 236a Window 237 Temperature sensor 238 Printed circuit boards 239 Soldering terminals 240 Bonding Wire 25 Heating section 251 Heat source resistance element 26 Cooling section 27 Memory section 28 buses 30 Image forming apparatus 31 Control Unit 32 Storage section 33 Operation section 34 Display section 35 Interfaces 36 Scanners 37 Image Processing Unit 38 Image forming unit 381 Exposure area 382 Photoconductor Drum 383 Developing Department 384 Transfer Forms 385 Secondary Transfer Roller 39 Image fixing unit 40 Conveying section 401 Reversing Mechanism 41 Bus P paper

Claims

1. A media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper, A moisture sensor having a light-emitting unit that emits light and a light-receiving unit that receives light reflected by the paper or transmitted through the paper, A temperature control unit controls the temperature of the light-emitting unit so that the wavelength of the light emitted from the light-emitting unit becomes a predetermined wavelength. A media detection device equipped with the following features.

2. The media detection device according to claim 1, wherein the temperature control unit controls the temperature of the light-emitting unit during the detection of moisture information based on the measurement results from a temperature sensor located near the light-emitting unit.

3. The media detection device according to claim 1, comprising at least one of a heating unit for heating the light-emitting unit and a cooling unit for cooling the light-emitting unit.

4. The media detection device according to claim 3, wherein the temperature control unit heats the light-emitting part by passing an electric current through a resistive element located near the light-emitting part of the heating unit.

5. The media detection device according to claim 3, wherein the temperature control unit cools the light-emitting unit with at least one of the fan motor and Peltier element of the cooling unit.

6. The media detection device according to claim 1, wherein the light-emitting unit comprises an LED (Light Emitting Diode) element or a laser diode element.

7. The media detection device according to claim 1, wherein the temperature control unit controls the temperature of the light-emitting unit based on temperature characteristic information indicating the correspondence between the wavelength of light and the temperature of the light-emitting unit for each light-emitting element of the light-emitting unit.

8. The media detection device according to claim 7, further comprising a storage unit for storing the aforementioned temperature characteristic information.

9. The media detection device according to claim 1, wherein the temperature control unit controls the temperature of the light-emitting unit before detecting the moisture information.

10. The media detection device according to claim 9, wherein the temperature control unit controls the temperature of the light-emitting unit by passing an electric current through the light-emitting element of the light-emitting unit when moisture information is not detected.

11. The media detection device according to claim 9, wherein the temperature control unit controls the temperature of the light-emitting unit by changing the duty cycle of the current flowing through the light-emitting unit when moisture information is not detected.

12. The media detection device according to claim 9, wherein the temperature control unit controls the temperature of the light-emitting unit during the detection of moisture information based on the measurement result from a temperature sensor located near the light-emitting unit or the measurement result of the ambient temperature.

13. The media detection device according to any one of claims 1 to 12, An image forming unit capable of forming an image on the aforementioned paper, An image forming system comprising the following features.

14. A media detection device for detecting moisture information corresponding to the moisture content or moisture ratio of paper, A computer for a media detection device that includes a moisture sensor having a light-emitting unit that emits light and a light-receiving unit that receives light reflected by or transmitted through the paper, A program that functions as a temperature control unit, controlling the temperature of the light-emitting unit so that the wavelength of the light emitted from the light-emitting unit becomes a predetermined wavelength.

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