Image forming apparatus, image forming method, and program

Abstract

To change settings related to determination of the type of a sheet according to the situation of use of an image forming apparatus.SOLUTION: An image forming apparatus 100 performs image formation in any one mode of an automatic detection mode for performing image formation with the type of a sheet S discriminated by sheet type discrimination means, and a type designation mode for performing image formation with the type of the sheet S received by sheet type designation receiving means. When the type designation mode is set, a control unit 108 determines whether to switch the mode from the type designation mode to the automatic detection mode on the basis of the fact that open and close detection means 111 detects at least either one of an opening operation or a closing operation.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, an image forming method, and a program.

Background Art

[0002] Conventionally, there is known an image forming apparatus including a sheet type discrimination means (referred to as a "paper type sensor" in Patent Document 1) for detecting the type of a sheet (paper). When printing is performed on different types of sheets, the result may not always be as expected. For this reason, for example, Patent Document 1 describes that printing is stopped when the information on the sheet type detected by the sheet type discrimination means is different from the information on the sheet type specified from the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even when a sheet type discrimination means is provided, it is possible to perform an automatic setting for determining the type of sheet used for printing based on the automatic discrimination result by the sheet type discrimination means and a manual setting for determining the type of sheet based on the manual setting of the user. However, there are also users who cannot correctly discriminate and set the type of sheet to be used. There are also users who do not recognize that the automatic setting / manual setting is selectable.

[0005] For such users, if the image forming apparatus is in a state where the sheet type is manually set, when using a plurality of types of sheets, it is necessary to manually change the sheet type setting each time, which is troublesome and time-consuming. Also, in the case of a user who has no knowledge about the sheet type, it is assumed that the user may not be able to correctly set the sheet type and may not obtain a normal printing result.

[0006] On the other hand, some users may want to use the image forming apparatus with manual settings. In this case, if the setting is automatically changed each time, the user will feel annoyed about having to return the setting to the manual setting each time of use. Also, there are users who use sheets with a fixed type or sheets that are difficult to automatically discriminate.

[0007] Also, when the automatic detection setting is enabled while a sheet that is not suitable for automatic detection is set, the sheet type may be misdetected during use. As a result, there is a concern about a decrease in productivity and the occurrence of jams. Furthermore, in the determination of the sheet type, when the image forming apparatus has both automatic and manual settings, if it is uniformly switched from the manual setting to the automatic setting, there may be a case where the setting goes against the user's intention. Therefore, for the determination of the sheet type, it is desired that the setting be the most user-friendly according to various scenarios.

[0008] The present invention has been made in view of the above points, and an object thereof is to provide an image forming apparatus, an image forming method, and a program capable of changing the setting related to the determination of the sheet type according to the usage state of the image forming apparatus.

Means for Solving the Problems

[0009] In order to solve the above problems, the image forming apparatus of the present invention includes a supply means for supplying a sheet, a sheet type discrimination means for discriminating the type of the sheet supplied by the supply means, Sheet type specifying reception means for receiving specification of the sheet type by the user An automatic detection mode for forming an image on the supplied sheet in the sheet type determined by the sheet type determination means, and a type specification mode for forming an image on the supplied sheet in the sheet type received by the sheet type specifying reception means, and an image forming means for performing image formation in any one of the modes Mode setting means for determining and setting which mode the image forming means performs image formation in Switching determination means for determining whether to switch the mode set by the mode setting means Switching means for automatically switching the mode when the image forming means forms an image when it is determined by the switching determination means that the mode is to be switched Detection means for detecting at least one of the operations of opening or closing the paper cassette for accommodating the sheet by user operation Comprising When the type specification mode is set by the mode setting means, the switching determination means determines whether to switch the mode from the type specification mode to the automatic detection mode based on at least one of the detected opening operation or closing operation by the detection means

Effect of the Invention

[0010] According to the present invention, the setting regarding the determination of the sheet type can be changed according to the usage status of the image forming apparatus, and the usability can be improved

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, an embodiment of an image forming apparatus, an image forming method, and a program according to the present invention will be described with reference to the drawings. Note that although various technically preferable limitations are imposed on the following embodiments for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0013] <First Embodiment> [Configuration of Image Forming Apparatus 100] FIG. 1 is a diagram showing a schematic configuration inside an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing the main functional configuration of the image forming apparatus. As shown in FIG. 1, the image forming apparatus 100 includes a sheet feeding unit 101, an image forming unit 102, a scanner unit 103, an ADF 104, an operation display unit 105, a power supply unit 107, and the like. Also, as shown in FIG. 2, it includes a transmission / reception unit 106, a control unit 108, a storage unit 109, and the like. And each unit is connected by a bus 110.

[0014] The image forming apparatus 100 prints (forms an image) a full-color or monochrome image on a sheet S by an electrophotographic method based on image data. The image data is image data of a document input from an external terminal device or the like via a transmission / reception unit 106 (see FIG. 2) connected to a network (for example, a LAN), or image data input by reading a document with the scanner unit 103. Note that in the embodiment, the sheet S is various recording media. In the following, even when the term "paper" is used as a term indicating the sheet S, it is not limited to so-called "paper", but widely includes various sheet-like recording media used as printing targets, such as plain paper and OHP sheets, in addition to various recording papers.

[0015] The scanner unit 103 and an ADF (Auto Document Feeder) 104 are provided above the image forming apparatus 100. The ADF 104 automatically feeds a document to the document table. The scanner unit 103 is configured to include a scanner (not shown) below the contact glass (original document table) on which the original document is placed, and reads an image of the original document. The scanner is composed of a light source, a CCD (Charge Coupled Device), an imaging optical system, an A / D converter, etc. The illumination light from the light source scans the original document, and the reflected light from the original document surface forms an image on the CCD. The image of the original document is photoelectrically converted by the CCD and read as R, G, B signals. The read image is converted from an analog signal to a digital signal by the A / D converter and output to the image processing unit 20. Here, the image includes not only image data such as graphics and photos, but also text data such as characters and symbols that have been converted into image data.

[0016] Also, an operation display unit 105 is provided above the image forming apparatus 100. The operation display unit 105 is a display means having a display panel 115 such as an LCD (Liquid Crystal Display). On the display panel 115, a screen for notifying the user of various device states and messages is appropriately displayed. Also, the display panel 115 is integrally configured with a touch panel that can be touched by the user. The user of the image forming apparatus 100 can specify the type of the sheet S to be used for printing, the type of printing, etc. by operating the operation display unit 105 (the touch panel of the operation display unit 105). The type of the sheet S is, for example, the difference between plain paper and various special papers, or the specification of the size, etc. Also, the type of printing is, for example, color printing or monochrome printing, double-sided printing or single-sided printing, etc. The content input by the user from the operation display unit 105 (the touch panel of the operation display unit 105) is received by the control unit 108.

[0017] In addition, as will be described later, the image forming apparatus 100 of the present embodiment has an automatic detection mode for forming an image based on the type of sheet discriminated by the sheet type discrimination function, and a type designation mode for forming an image based on the type of sheet received by the sheet type designation reception function. And the image forming unit 102 of the image forming apparatus 100 can perform image formation in any of these modes. The user can set which mode to perform image formation by operating the operation display unit 105 (the touch panel of the operation display unit 105). Furthermore, on the display panel 115 of the operation display unit 105, various guidance screens, inquiry screens, setting screens, etc. are appropriately displayed based on the control of the control unit 108. Specific examples of the display screens will be described later.

[0018] Also, as shown in FIG. 1, the image forming apparatus 100 of the embodiment has a sheet supply means 101 at a lower position of the apparatus. Above the sheet supply means 101 in the image forming apparatus 100, an image forming unit 102 for forming an image on the sheet S supplied by the sheet supply means 101 is provided.

[0019] The sheet supply means 101 includes a plurality of paper cassettes 11 and a plurality of conveying means for sending out the sheet S onto the conveying path R from the paper cassette 11. The conveying means is, for example, a conveying roller 12 (see FIG. 1). Each paper cassette 11 accommodates various sheets S. The conveying roller 12 is controlled to operate by the control unit 108 described later, and sends out the sheets S used for printing one by one to the conveying path R.

[0020] In FIG. 1, the case where four paper cassettes 11a, 11b, 11c, and 11d are prepared as the paper cassettes 11 is illustrated. The configurations of the paper cassettes 11a, 11b, 11c, and 11d are substantially the same, and when simply referred to as "paper cassette 11", it includes all of these. Note that the number of paper cassettes 11 is not limited to four, and it may be more or less than this. The same type of sheet S may be accommodated in each paper cassette 11, or sheets S of different paper types may be accommodated respectively.

[0021] When the sheet S accommodated in the paper cassette 11 is used up and the inside of the paper cassette 11 becomes empty, the printing operation stops once and enters a standby state (stop state) until the sheet S is replenished. In this case, the user opens and closes the paper cassette 11 to replenish the sheet S into the paper cassette 11. Each paper cassette 11 is provided with opening / closing detection means 111 for detecting at least one of an operation of opening the paper cassette 11 by a user operation (opening operation) or an operation of closing it (closing operation).

[0022] FIG. 3 is an explanatory diagram schematically showing how the paper cassette is opened and closed by a user operation. As shown in FIG. 3, the paper cassette 11 of the present embodiment is in an open state by being pulled out to the front side (front side) of the apparatus, and is in a closed state by being pushed into the inner side of the apparatus. Since the paper cassettes 11a, 11b, 11c, and 11d all have substantially the same configuration, they are shown without distinction in FIG. 3.

[0023] The opening / closing detection means 111 may be any means capable of detecting an opening / closing operation as shown in FIG. 3, and the specific position and configuration of providing the opening / closing detection means 111 are not particularly limited. The opening / closing detection means 111 may be, for example, a sensor that detects light inserted into the paper cassette 11 when the paper cassette 11 is opened and closed. Also, the opening / closing detection means 111 may be various optical sensors such as a sensor including a light emitting part and a light receiving part, which detects that the light from the light emitting part is blocked when the paper cassette 11 is opened and closed. Further, the opening / closing detection means 111 may be various switches of a mechanical configuration that detect opening and closing, for example, by a convex part or the like being pushed in or released when the paper cassette 11 is opened and closed. The detection result by the opening / closing detection means 111 is output to the control unit 108 described later and acquired by the control unit 108.

[0024] The sheet S fed out onto the conveyance path R from the paper cassette 11 is sent to the image forming unit 102 by the conveyance roller 12. On the conveyance path R, a registration roller 13 is provided upstream of the image forming unit 102. The sheet S conveyed on the conveyance path R hits the registration roller 13 once and is then sent to the image forming unit 102 at an appropriate timing. A media detection sensor 20 is provided immediately downstream of the confluence position of each paper cassette 11 and upstream (before) of the registration roller 13. By providing the media detection sensor 20 at this position, the sheet S always passes through the detection position of the media detection sensor 20 before being sent to the image forming unit 102, regardless of which paper cassette 11 the sheet S is fed out from.

[0025] The media detection sensor 20 is a measuring means that irradiates light onto the sheet S and measures the physical properties of the sheet S based on the transmittance and reflectance of the irradiated light. As described above, the image forming apparatus 100 has, as image forming modes, an automatic detection mode for automatically detecting the sheet type and a type designation mode in which the user manually designates the sheet type. In the automatic detection mode, the media detection sensor 20 detects various values that serve as judgment materials when the control unit 108 discriminates (estimates) the type of the sheet S. For example, the media detection sensor 20 outputs a signal indicating the basis weight of the sheet S. Note that the media detection sensor 20 may output a signal indicating a characteristic value other than the basis weight of the sheet S. The control unit 108 described later refers to the output signal of the media detection sensor 20 and automatically discriminates (estimates) the type of the sheet S based on the detection result (measurement result) by the media detection sensor 20.

[0026] Here, the configuration of the media detection sensor 20 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, in the present embodiment, conveyance guide plates 131 and 132 for guiding the sheet S to the resist roller 13 are provided on the conveyance path R, and the medium detection sensor 20 is attached to these conveyance guide plates 131 and 132. Note that the medium detection sensor 20 may be fixed to other members.

[0027] As shown in FIG. 5, the medium detection sensor 20 includes a light emitting substrate 21 and a light receiving / emitting substrate 22. On the light emitting substrate 21, an LED (Light Emitting Diode) 211 that emits near-infrared light IR and an LED 212 that emits blue light B are mounted. The emitted lights IR and B of the LEDs 211 and 212 are irradiated onto the sheet S via a through hole 133 provided in the conveyance guide plate 132. A part of the light irradiated onto the sheet S is transmitted and travels toward the light receiving / emitting substrate 22.

[0028] Further, on the light receiving / emitting substrate 22, an LED 221 that emits green light G and a photodiode 222 that outputs a detection signal according to the incident light amount are mounted. The emitted light G of the LED 221 is irradiated onto the sheet S via a through hole 134 provided in the conveyance guide plate 131. A part of the light irradiated onto the sheet S is reflected and travels toward the photodiode 222.

[0029] When there is no sheet S on the optical path where the near-infrared light IR and the blue light B travel from the LEDs 211 and 212 to the photodiode 222, the near-infrared light IR and the blue light B directly enter the photodiode 222 without being blocked by the sheet S. Based on this incident light amount, the transmittance of the near-infrared light IR and the blue light B is evaluated for each recording sheet.

[0030] On the surface of the conveyance guide plate 132 facing the light-receiving and emitting substrate 22, a reference plate 23 for a reflection light source is disposed at the position where the emitted light G of the LED 221 is incident. When there is no sheet S on the optical path from the LED 221 to the reference plate 23 for a reflection light source and on the optical path from the reference plate 23 for a reflection light source to the photodiode 222, the green light G is reflected by the reference plate 23 for a reflection light source without being blocked by the sheet S and is incident on the photodiode 222. Based on this incident light amount, the reflectance of the green light G is evaluated for each sheet S.

[0031] The transmittance and reflectance of the near-infrared light IR, blue light B, and green light G may vary depending on the basis weight of the sheet S. Therefore, by calculating the transmittance of the near-infrared light IR and blue light B or calculating the reflectance of the green light G with reference to the detection signal of the photodiode 222, the basis weight of the sheet S can be determined.

[0032] The sheet S sent out on the conveyance path R is sent to the image forming unit 102 after passing through the detection position of the medium detection sensor 20. The image forming unit 102 forms a toner image with toners of each color of yellow (Y), magenta (M), cyan (C), and black (K), transfers it onto the sheet S supplied from the sheet supply means 101, and fixes it. The image forming unit 102 includes an intermediate transfer belt 41 disposed along the horizontal direction at substantially the center in the vertical direction of the apparatus. The intermediate transfer belt 41 is wound around a pair of belt circulating rollers 42 and 43 and is configured to circulate and move in the direction indicated by the arrow X by a motor (not shown).

[0033] Below the intermediate transfer belt 41, process units 30 (process units 30Y, 30M, 30C, 30K), each detachable from the apparatus main body, are provided. Each process unit 30 is arranged in that order along the circumferential movement direction of the intermediate transfer belt 41. And each of the process units 30 includes a plurality of process means for forming a toner image with toner of each color of yellow (Y), magenta (M), cyan (C), and black (K). Each process unit 30 can be removed from the apparatus main body by being pulled out toward the front side (the front side of the paper surface in FIG. 1) with respect to the apparatus main body. Further, each process unit 30 can be attached to the apparatus main body by being inserted toward the inner back side with respect to the apparatus main body. Note that the toner is not limited to the four colors shown here. When toner of other colors is provided, a process unit for forming a toner image with the toner is further provided.

[0034] Above the intermediate transfer belt 41, toner storage portions (not shown) are provided at upper positions of the process units 30Y, 30M, 30C, and 30K, sandwiching the intermediate transfer belt 41. Each toner storage portion stores toner of each color of yellow (Y), magenta (M), cyan (C), and black (K). The respective toners stored in the toner storage portions corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) are supplied to each process unit 30 by a toner supply mechanism (not shown).

[0035] Each of the process units 30Y, 30M, 30C, and 30K has a photosensitive drum 31 rotatably arranged to face the intermediate transfer belt 41 below the intermediate transfer belt 41. A photosensitive layer is provided over the entire surface of each photosensitive drum 31, and each is adapted to be rotated in the direction indicated by arrow Z. Chargers 32 for uniformly charging the photosensitive layer of the photosensitive drum 31 to a predetermined charging potential are provided in that order along the rotation direction on the downstream side in the rotation direction of each photosensitive drum 31 with respect to the upper portion of the photosensitive drum 31 facing the intermediate transfer belt 41.

[0036] On the photosensitive drum 31 charged by the charger 32, laser lights LY, LM, LC, and LK are irradiated from the exposure device 47 on the downstream side in the rotation direction of the photosensitive drum 31 with respect to the charger 32. Four semiconductor laser elements are provided in the exposure device 47. The laser lights LY, LM, LC, and LK emitted from the respective semiconductor laser elements of the exposure device 47 based on the image data are irradiated onto the photosensitive layer of each photosensitive drum 31 through a polygon mirror, a scanning lens, etc. Thereby, an electrostatic latent image is formed on the photosensitive layer of each photosensitive drum 31 uniformly charged by each charger 32.

[0037] In each process unit 30, a developing device 33 is provided on the downstream side in the rotation direction with respect to the exposure position of each photosensitive drum 31 by the laser lights LY, LM, LC, and LK. Each developing device 33 toner-develops the electrostatic latent image formed on the photosensitive layer of each photosensitive drum 31 using a two-component developer having toner of each color of Y, M, C, and K and a carrier having magnetism.

[0038] Each of the photosensitive drum 31, the charger 32, and the developing device 33 in each process unit 30 constitutes a process means for forming a toner image. Note that the configuration of the process means provided in each of the process units 30Y, 30M, 30C, and 30K is the same for each process unit 30. For this reason, in FIG. 1, Y, M, C, and K are not distinguished by being attached. Also, FIG. 1 is merely a schematic diagram and does not accurately show the arrangement, shape, etc. of each component.

[0039] Above each process unit 30, primary transfer rollers 44Y, 44M, 44C, and 44K facing each photosensitive drum 31 with the intermediate transfer belt 41 interposed therebetween are provided. Each primary transfer roller 44Y, 44M, 44C, and 44K is attached to the apparatus main body. Each primary transfer roller 44Y, 44M, 44C, and 44K forms an electric field with the corresponding photosensitive drum 31 by applying a transfer bias voltage. Each toner image formed on each photoreceptor drum 31K is primarily transferred onto the intermediate transfer belt 41 by the action of an electric field formed between the primary transfer rollers 44Y, 44M, 44C, 44K and each photoreceptor drum 31.

[0040] In the case of forming a full-color image, the respective image forming operation timings of each of the process units 30Y, 30M, 30C, 30K are shifted so that the respective toner images formed on each photoreceptor drum 31 are multiply transferred onto the same area on the intermediate transfer belt 41. On the other hand, in the case of forming a monochrome image, a toner image is formed only on the photoreceptor drum 31 of the selected one process unit (for example, the process unit 30K for K toner), and the formed toner image is transferred onto a predetermined area on the intermediate transfer belt 41 by the primary transfer roller 44K arranged to face the said process unit.

[0041] Although not shown in the figure, each process unit 30 is provided with a cleaning member. Each photoreceptor drum 31 onto which the toner image has been transferred has the toner remaining on the surface scraped off by this cleaning member.

[0042] The intermediate transfer belt 41 conveys the transferred toner image to the end (the right end in FIG. 1) around which one of the belt turning rollers 42 is wound by circumferential movement. A secondary transfer roller 45 is arranged to face the belt turning roller 42 with the intermediate transfer belt 41 therebetween. The secondary transfer roller 45 is in pressure contact with the intermediate transfer belt 41, and a transfer nip is formed therebetween. A transfer bias voltage is applied to the secondary transfer roller 45. By applying the transfer bias voltage, an electric field is formed between the secondary transfer roller 45 and the intermediate transfer belt 41. The transfer nip formed by the secondary transfer roller 45 and the intermediate transfer belt 41 conveys the sheet S fed from the paper cassette 11 of the sheet feeding means 101 to the conveyance path R. The toner image transferred onto the intermediate transfer belt 41 is secondarily transferred onto the sheet S conveyed along the conveyance path R by the action of an electric field formed between the secondary transfer roller 45 and the intermediate transfer belt 41.

[0043] The sheet S that has passed through the transfer nip is conveyed to a fixing device 50 disposed above the secondary transfer roller 45. The fixing device 50 includes a heating roller 51 and a pressure roller 52 that are pressed against each other. A fixing nip is formed between the two due to the heating roller 51 and the pressure roller 52 being pressed against each other. A heating means 511 is disposed at the axial center of the heating roller 51. The heating means 511 is, for example, a heater lamp. The heating roller 51 is heated by the heating means 511. In the fixing device 50, the unfixed toner image on the sheet S is fixed by being heated and pressed while passing through the fixing nip formed by the heating roller 51 and the pressure roller 52. The sheet S on which the toner image has been fixed is discharged onto a paper discharge tray 15 disposed above the process unit 30 and the like by a paper discharge roller 14.

[0044] Here, an embodiment has been described in which the image forming unit 102 of the image forming apparatus 100 forms an image by an electrophotographic method. However, the image forming unit of the image forming apparatus may be of another method such as an inkjet method.

[0045] Further, the control unit 108 of the image forming apparatus 100 includes, for example, a CPU (Central Processing Unit) not shown in the figure, a ROM (Read Only Memory) which is a non-volatile memory, a RAM (Random Access Memory) which is a volatile memory, and the like. These are connected to be mutually communicable via internal buses (none of which are shown in the figure). The CPU of the control unit 108 reads out various processing programs stored in the ROM or the like and expands them in the RAM. Then, the CPU comprehensively controls the operations of each part of the image forming apparatus 100 in cooperation with the various programs expanded in the RAM. For example, when the CPU receives a reset signal triggered by, for example, the power of the image forming apparatus 100 being turned on, it reads out the boot program from the ROM and starts up. Then, using the RAM as a working storage area, the CPU executes the OS (Operating System) and control programs read from the HDD (Hard Disk Drive), which is an auxiliary storage device. Note that instead of the HDD, an SSD (Solid State Drive) may be used as the auxiliary storage device.

[0046] The storage unit 109 is composed of a DRAM (Dynamic Random Access Memory), an HDD (Hard Disk drive), and the like, and stores the image data input by the scanner unit 103, the image data input from the outside via the transmission / reception unit 106, and the like. Note that these image data and the like may be stored in the RAM or the like of the control unit 108.

[0047] Also, the storage unit 109 in the embodiment stores determination information for determining the type of the sheet S. The determination information is information indicating the type of the sheet S estimated from the output signal of the medium detection sensor 20. For example, the medium detection sensor 20 outputs a signal indicating the basis weight of the sheet S. In this case, the determination information is a table or the like in which the signal indicating the basis weight and the type of the sheet S corresponding thereto are defined. Note that the determination information may be any information as long as the control unit 108 can estimate the type of the sheet S based on the output signal (output information) from the medium detection sensor 20, and the specific content is not limited.

[0048] As described above, in this embodiment, as modes for setting the sheet type when the image forming unit 102 performs image formation, there are an automatic detection mode and a type designation mode. The control unit 108 also functions as mode setting means for determining and setting which mode the image forming unit 102 performs image formation in. For example, at the time of factory shipment, etc., the automatic detection mode is set as the default. In the automatic detection mode, the control unit 108 functions as sheet type discrimination means for referring to the output signal of the medium detection sensor 20 and discriminating (estimating) the type of the sheet S supplied by the sheet supply means 101.

[0049] Also in the embodiment, the control unit 108 functions as sheet type designation reception means for receiving the designation of the type of the sheet S by the user. That is, the user can set the type designation mode by an input operation to the operation display unit 105 or the like. In this case, the type of the sheet S designated by the user by an operation to the operation display unit 105 or the like is received by the control unit 108.

[0050] When the type of the sheet S used for image formation is determined by either automatic (automatic detection mode) or manual designation by the user (type designation mode), the control unit 108 sets the process conditions so that image formation corresponding to the determined type of the sheet S is performed. The process conditions for forming a high-quality image differ according to the type of the sheet S. For this reason, in order to form a high-quality image for various sheets S, it is necessary to set suitable process conditions according to the characteristics of each sheet S. Here, the process conditions include, for example, the secondary transfer voltage, the fixing temperature, the paper conveyance speed, and the like.

[0051] The type of the sheet S and the process conditions corresponding to the sheet type are stored, for example, in the storage unit 109 or the like. When the sheet S used for image formation is determined, the control unit 108 acquires the corresponding process conditions from the storage unit 109 and appropriately controls the operations of each part of the image forming unit 102 and the conveyance roller 12 or the like.

[0052] Further, the control unit 108 also functions as a switching determination unit that determines whether to switch the mode (automatic detection mode or type designation mode) set as the mode setting unit. Then, when the control unit 108 determines to switch the set mode to the other mode, it also functions as a switching unit that automatically switches the mode when the image forming unit 102 forms an image.

[0053] In the present embodiment, as described above, when the opening / closing detection unit 111 detects at least one of an operation (opening operation) in which the paper cassette 11 for accommodating the sheet S is opened by a user operation or an operation (closing operation) in which it is closed, a detection signal is output to the control unit 108. Thereby, the control unit 108 detects that the paper cassette 11 has been opened or closed. Then, when detecting that the paper cassette 11 has been opened or closed, the control unit 108 determines, as a switching determination unit, whether to switch the mode based on the opening operation or closing operation of the paper cassette 11. For example, when the type designation mode is set as the mode for determining the sheet type, the control unit 108 determines whether to switch the mode from the type designation mode to the automatic detection mode. Note that the specific method of determination will be described later.

[0054] In addition, as shown in FIG. 2, the image forming apparatus 100 includes a transmission / reception unit 106. The transmission / reception unit 106 includes, for example, a NIC (Network Interface Card) or the like. Then, it executes processing for communicating with other devices (various external devices) via a communication network such as a LAN (Local Area Network) or the Internet. Thereby, the image forming apparatus 100 can receive image data, an image forming job, or the like from another device connected to the communication network. The image forming job may include setting of the type of the sheet S used for the image forming process. The image forming apparatus 100 also includes a power supply unit 107 connected to an external power source. The power supply unit 107 is connected to a control unit 108 and supplies the necessary power to each unit.

[0055] [Operation of image forming apparatus and image forming method] Next, the operation of image forming apparatus 100 will be described, focusing in particular on the process related to mode switching when setting the sheet type. In this embodiment, the automatic detection mode, which automatically sets the type of sheet S used for image formation, is the default setting. That is, in a state where no setting is made by the user, information (determination information) for determining the sheet type is automatically acquired when the sheet S conveyed from the sheet supplying means 101 passes the detection position of the medium detection sensor 20. The control unit 108, which receives this detection result (determination information), automatically determines (estimates) the type of the sheet S based on the determination information.

[0056] In the embodiment, when the user opens or closes the paper cassette 11, the control unit 108 determines whether or not to switch the mode for setting the sheet type in response to the opening or closing action. FIG. 6 is a flowchart illustrating a flow of determining whether to switch the mode when setting the sheet type.

[0057] 6, when an image forming operation is started, the control unit 108 constantly determines whether the paper cassette 11 has been opened or closed (step S1). The determination of whether the paper cassette 11 has been opened or closed is based on the detection result output from the open / close detection means 111. That is, the control unit 108 constantly determines whether the open / close detection means 111 has output a detection result indicating that the paper cassette 11 has been opened or closed. Then, while the open / close detection means 111 has not output a detection result (step S1; NO), the control unit 108 repeats the determination process until the detection result is output.

[0058] When a detection result indicating an open operation or a close operation is output from the opening / closing detection means 111, it is determined that the paper cassette 11 has been opened or closed (step S1; YES). In this case, the control unit 108 further determines whether the currently set mode is a type designation mode in which the sheet type is set by user designation (step S2).

[0059] For example, FIGS. 7A and 7B are examples of a setting screen of the operation display unit 105 for setting the "sheet size" and "sheet type". In FIGS. 7A and 7B, they are shown as "paper size" and "paper type". The setting screen 115a is provided with an ON / OFF selection button 152 for determining whether to perform automatic detection of the sheet type. When the user selects "OFF" with the ON / OFF selection button 152, a mode (type designation mode) in which the user manually designates the sheet type without performing automatic detection is set. FIG. 7A shows a state in which the type designation mode is set. Also, when the user selects "ON" with the ON / OFF selection button 152, a mode (automatic detection mode) in which the sheet type is automatically detected is set. FIG. 7B shows a state in which the automatic detection mode is set.

[0060] Note that the setting screen 115a is appropriately provided with, for example, a start button 153 for starting printing, a stop button 154 for stopping printing, a reset button 155 for resetting all settings, and the like.

[0061] When the currently set mode is not the type designation mode (step S2; NO), that is, when the current setting is the automatic detection mode, the control unit 108 does not switch the mode and ends the process. On the other hand, when the currently set mode is the type designation mode (step S2; YES), the control unit 108, as switching determination means, determines whether to switch the mode for setting the sheet type.

[0062] In this embodiment, instead of always switching modes when there is an open or close operation of the paper cassette 11 by the user, the control unit 108 determines whether to switch modes according to the type of the sheet S specified in the type specification mode. That is, when an open or close operation of the paper cassette 11 is detected while the type specification mode is set, the control unit 108 further determines whether the sheet type specified by the user is a sheet S that can be automatically discriminated (step S3). Whether the sheet S is of a type that can be automatically discriminated is determined by the control unit 108 referring to a list stored in, for example, the storage unit 109 or the like.

[0063] FIG. 8 is a diagram showing an example of a list stored in the storage unit. When the sheet S specified by the user is classified as a sheet that is not suitable for automatic discrimination, such as special papers a, b, c, etc. (the left column in FIG. 8), the control unit 108 determines that the sheet S is not suitable for automatic discrimination of the sheet type (step S3; NO). In this case, the control unit 108 controls to maintain the mode received by the input to the user operation display unit 105 (step S4). Thereby, even after the opening and closing operation of the paper cassette 11, the operation continues in the type specification mode in which the user manually specifies the sheet type (step S5).

[0064] On the other hand, when the sheet S specified by the user is classified as a sheet S that can be automatically discriminated, such as plain paper (the right column in FIG. 8), the control unit 108 determines that the sheet type is a sheet S that can be automatically discriminated (step S3; YES). In this case, the control unit 108 controls to return the mode for setting the sheet type to the default (step S6). Thereby, after the opening and closing operation of the paper cassette 11, the operation is performed in the automatic discrimination mode (step S7).

[0065] When switching between the automatic detection mode and the type specification mode, it is preferable that the control unit 108 causes a message or the like to be displayed on the display panel 115 of the operation display unit 105 to notify the user. Further, when a message is displayed on the display panel 115 regarding a setting change for switching between the automatic detection mode and the type specification mode, it is preferable to have a plurality of message display methods. Figures 9A to 9C are examples of display screens when a message is displayed on the display panel regarding a setting change for switching between the automatic detection mode and the type specification mode.

[0066] For example, in FIG. 9A, an example is illustrated where the message display 156 displayed on the display screen 115b of the display panel 115 only prompts the user for a setting change to the automatic detection mode. A message is displayed on the display panel 115 to ask the user whether to change the type specification mode to the automatic detection mode. When the YES button 157 is operated, the mode is switched, but when the NO button 158 is operated, the mode is not switched. In this way, the control unit 108 as the switching means may not switch the mode when the image forming unit 102 forms an image unless there is an instruction for setting change by the user.

[0067] Also, in FIG. 9B, an example is illustrated where the message display 159 displayed on the display screen 115b of the display panel 115 notifies a forced setting change to the automatic detection mode. In this case, the control unit 108 as the switching means forcibly switches the mode to the automatic detection mode when the image forming unit 102 forms an image.

[0068] Also, when the setting change to the automatic detection mode is prompted but the user rejects the setting change, for example, as shown in FIG. 9C, it may be possible to make a selection such as "Do not display this message in the future". That is, for example, in the message display 160 on the display screen 115b shown in FIG. 9C, when the user selects the NO button 162, the display panel 115 does not redisplay the setting change unless the check box for the display of "Do not display this message in the future" is deselected.

[0069] In addition, after changing the setting to the automatic detection mode, it is also possible for the user to select to return to the original setting (i.e., the type designation mode) again. In this case, once the selection to return to the original setting is made, it may not be necessary to redisplay the setting change on the display screen 115b of the display panel 115. Also, similar to that shown in FIG. 9C, a message such as "Do not display this message in the future" may be displayed. And if the check box for this message is not deselected, it may not be necessary to redisplay the setting change on the display panel 115.

[0070] [Effect] As described above, the image forming apparatus 100 according to the present embodiment includes an automatic detection mode for automatically discriminating the type of the sheet S and a type designation mode for the user to manually specify the type of the sheet S. The image forming unit 102 forms an image on the sheet S in either the automatic detection mode or the type designation mode. The control unit 108, as a mode setting means, determines and sets in which mode the image forming unit 102 forms an image. The control unit 108 also serves as a switching determination means for determining whether to switch the set mode. When it is determined to switch the mode, the control unit 108, as a switching means, automatically switches the mode when the image forming unit 102 forms an image. Further, the control unit 108 as the switching determination means, when the type designation mode is set, determines whether to switch the mode from the type designation mode to the automatic detection mode when it is detected that the paper cassette 11 for accommodating the sheet S is opened or closed by a user operation.

[0071] Users who use the image forming apparatus 100 vary from those with knowledge about sheet types and the like to those without such knowledge. For this reason, when setting the type of the sheet S, if the automatic and manual modes are uniformly switched, image formation may be performed on an unintended type of sheet S, and a high-quality finish may not be achieved. In this regard, in the embodiment, a determination is made as to whether or not to switch the mode for setting the type of sheet S when a user opens and closes paper cassette 11. This makes it possible to change the settings related to sheet type determination according to the usage status of image forming apparatus 100, making it possible to meet the needs of various users and improving usability.

[0072] Moreover, the control unit 108 judges whether to switch the mode depending on the type of sheet S specified in the type specification mode when the open / close detection unit 111 detects the opening / closing operation of the paper cassette 11. This makes it possible to take action in response to the user's action and in accordance with the type of sheet S. This improves the usability of the image forming apparatus 100.

[0073] Moreover, when the sheet S specified in the type specification mode is a sheet that cannot be identified by the sheet type identification means, the control unit 108 determines to maintain the type specification mode without switching the mode. If the sheet S is unidentifiable letter, switching to automatic detection mode using the media detection sensor 20 may result in misidentification of the sheet type. If process conditions are set and image formation is performed with a different sheet type set, high quality results may not be obtained. In this regard, by maintaining the type designation mode, which is a manual setting, when unidentifiable letter is specified, it is possible to set the correct and appropriate sheet type.

[0074] Furthermore, when the sheet specified in the type specification mode is a sheet that can be identified by the sheet type identification means, the control unit 108 determines to switch the type specification mode to the automatic detection mode. The automatic detection mode is convenient because it does not require the user to set the sheet type each time, even when multiple types of sheets S are used. Therefore, when the sheet type can be correctly determined based on the detection results of the media detection sensor 20, the burden on the user can be reduced by using the automatic detection mode.

[0075] Further, the image forming apparatus 100 according to the embodiment has a display panel 115 and includes an operation display unit 105 for notifying the user of various device states, messages, and the like. When switching between the automatic detection mode and the type designation mode, it is displayed on the display panel 115. Thereby, the user can recognize that the mode is switched. For this reason, it is possible to prevent image formation from being performed on the wrong sheet S without noticing the mode switch.

[0076] In the present embodiment, when a message is displayed on the display panel 115 regarding a setting change for switching between the automatic detection mode and the type designation mode, there are a plurality of message display methods. For example, the message displayed on the display panel 115 may simply prompt the user to change the setting to the automatic detection mode. In this case, the control unit 108 may not switch the mode when the image forming unit 102 forms an image unless the user gives an instruction to change the setting. In this case, it is possible to notify a user who is not aware of the existence of the automatic detection mode that the setting can be changed to the automatic detection mode, and the user can be entrusted with the decision of whether to switch.

[0077] Further, the message displayed on the display panel 115 may notify a forced setting change to the automatic detection mode. In this case, the control unit 108 may forcibly switch the mode to the automatic detection mode when the image forming unit 102 forms an image. In this case, it is possible to inform the user that the mode has been changed, and it is possible to prevent a situation where the mode is suddenly switched and image formation is performed on an unintended sheet S. Also, it is possible to save the user's effort of responding to an inquiry about whether to switch or not.

[0078] Further, when a selection is made to return to the original setting after the setting is changed to the automatic detection mode, it may not be necessary to redisplay the setting change on the display panel 115. This can avoid the trouble of being asked to confirm each setting change.

[0079] Also, in the embodiment, the sheet type discrimination means includes a measurement means for irradiating light to the sheet S and measuring the physical properties of the sheet S based on the transmittance and reflectance of the irradiated light. The measurement means is, for example, the medium detection sensor 20. Based on the measurement result by such a measurement means, the control unit 108 discriminates the type of the sheet S, so that the sheet type can be discriminated easily and accurately, and the process conditions and the like can be set appropriately.

[0080] <Second Embodiment> Next, a second embodiment of the image forming apparatus, the image forming method, and the program according to the present invention will be described. In this embodiment, the process related to the switching of the mode when setting the sheet type is different from that in the first embodiment. Since the apparatus configuration is the same as that shown in the first embodiment, the description thereof will be omitted. In the following, the points different from the first embodiment will be particularly described.

[0081] In this embodiment, the control unit 108 functioning as the switching determination means determines whether to switch the mode according to the operation state of the image forming job when at least one of the opening operation or the closing operation of the paper cassette 11 is detected by the opening / closing detection means 111.

[0082] When at least one of the opening operation or the closing operation of the paper cassette 11 is detected by the opening / closing detection means 111 during a series of image forming jobs, the control unit 108 as the switching determination means determines to maintain the type designation mode without switching the mode. That is, when there is a currently executing job, even if the paper cassette 11 is opened or closed due to the sheet S in the paper cassette 11 running out during the job, the control unit 108 does not switch the mode thereby.

[0083] On the other hand, when at least one of the opening operation or the closing operation of the paper cassette 11 is detected by the opening / closing detection means 111 when there are no waiting and received image forming jobs, the control unit 108 as the switching determination means determines to switch the mode.

[0084] FIG. 10 is a flowchart for explaining the flow of mode switching determination when setting the sheet type in the present embodiment.

[0085] Note that step S11 and step S12 shown in FIG. 10 are the same as step S1 and step S2 shown in FIG. 6. Also, step S15 to step S18 shown in FIG. 10 are the same as step S4 to step S7 shown in FIG. 6. Therefore, here, step S13 and step S14 will be particularly described. Also in the present embodiment, similar to the first embodiment, when the currently set mode is the type designation mode for setting the sheet type by user designation (step S12; YES), the control unit 108 as the switching determination means determines whether to switch the mode for setting the sheet type.

[0086] In the present embodiment, when there is an opening or closing operation of the paper cassette 11 by the user, the mode is not always switched. Instead, as described above, the control unit 108 determines whether to switch the mode according to the operation state of the image forming job. That is, the control unit 108 first determines whether there is an image forming job currently being executed (step S13). If it is in the middle of the job currently being executed (step S13; YES), the control unit 108 controls each part to maintain the received mode (step S15 and step S16).

[0087] On the other hand, when there is no job currently being executed (step S13; NO), the control unit 108 further determines whether there is a job in a waiting state or a reserved job (step S14). When there is a job in a waiting state or a reserved job (step S14; YES), the control unit 108 controls each unit to maintain the received mode (steps S15 and S16).

[0088] In contrast, when there is no job in a waiting state or a reserved job at the current time (step S14; NO), the control unit 108 controls each unit to return the mode for setting the sheet type to the default (steps S17 and S18).

[0089] FIG. 11 is an explanatory diagram schematically showing the processing when there is one image forming job being executed in the type designation mode and there is no reserved job (waiting and received image forming jobs) that has already been input from the operation display unit 105 or the like and received by the control unit 108. In FIG. 11, the time series is set from left to right. As shown in FIG. 11, in this case, when the sheet S being used during image formation runs out, the image forming operation stops. The fact that the sheet S has run out is notified to the user by means of a display on the display panel 115 of the operation display unit 105 and various beep sounds.

[0090] When the user receives this notification, opens the paper cassette 11, sets (replenishes) the sheet S, and closes the paper cassette 11 again, this open or close operation is detected by the open / close detection means 111. Then, the detection result of the open / close detection means 111 is output to the control unit 108. However, as shown in step S13; YES in FIG. 10, when it is in the middle of an executing job, even if an open or close operation of the paper cassette 11 is detected, the mode is not switched. In this case, the control unit 108 controls to maintain the type designation mode. When an image forming job in which the type designation mode is set is being executed, it is assumed that the same user will continue to execute the image forming job even after replenishing the sheet S. For this reason, if the mode is switched midway, the user will feel inconvenienced. Also, depending on the type of the designated sheet S, there is a risk of unexpected errors occurring. Therefore, it is preferable to maintain the set mode.

[0091] On the other hand, when the image forming job in which the type designation mode is set ends and there are no jobs being executed or reserved, when the opening / closing operation of the paper cassette 11 is detected, the control unit 108 controls each unit so as to return the mode for setting the sheet type from the type designation mode to the default automatic detection mode.

[0092] Also, FIG. 12 shows a case where the paper cassette 11 is opened / closed when the image forming job being executed in the type designation mode ends. However, in the example shown in FIG. 12, the already reserved image forming jobs 1 and 2 have been received by the control unit 108. FIG. 12 is an explanatory diagram schematically showing the processing in the case where a plurality of image forming jobs are set. In FIG. 12 as well, the time series is set from left to right.

[0093] As shown in FIG. 12, when there are already reserved image jobs, even if a part of the received job has been completed, the reserved jobs are considered as one (series of) job as a whole. Then, even if the paper cassette 11 is opened / closed during the series of jobs, the control unit 108 controls to maintain the type designation mode without switching the mode.

[0094] Thus, when there are a plurality of reserved jobs, it is assumed that the same user will perform similar processing. For this reason, if the mode is switched midway, the user will feel inconvenienced. Also, depending on the type of the designated sheet S, there is a risk of unexpected errors occurring, and it is preferable to maintain the set mode.

[0095] Even when there are multiple jobs, if it is a new job separated from a series of jobs, the control unit 108 switches the mode when the opening and closing operation of the paper cassette 11 occurs. That is, when the opening and closing operation of the paper cassette 11 is detected before the start of the new job on the right side of FIG. 12, the control unit 108 controls each part so as to return the mode for setting the sheet type from the type designation mode to the default automatic detection mode at that time.

[0096] In which cases it is determined as a new job separated from a series of jobs is appropriately set. For example, it is conceivable that a predetermined time has elapsed from the end of a series of jobs to the acceptance of the next job. Also, a job accepted with a user ID different from the previous job or a job accepted from a different terminal device is considered a new job. In these cases, it is considered that there is little need to inherit the type designation of the sheet S set by the user. Therefore, it is preferable to process it as a new job in the default automatic detection mode.

[0097] Thus, in this embodiment, the control unit 108 as the switching determination means determines whether or not to switch the mode when at least one of the opening operation or the closing operation of the paper cassette 11 is detected by the opening / closing detection means 111, according to the operation state of the image forming job at that time. Thereby, while using the opening and closing of the paper cassette 11 as an opportunity for mode switching determination, it is possible to prevent the mode from being switched unintentionally during the image forming job.

[0098] Also, when at least one of the opening operation or the closing operation of the paper cassette 11 is detected by the opening / closing detection means 111 during a series of image forming jobs, the control unit 108 determines to maintain the type designation mode without switching the mode. Thereby, when the same user tries to continue the image forming job after replenishing the sheet S, it is possible to prevent the setting from being changed contrary to the intention.

[0099] Also, when at least one of the opening operation or closing operation of the paper cassette 11 is detected by the opening / closing detection means 111 when there is no waiting or received image forming job, the control unit 108 switches the mode from the type designation mode to the automatic detection mode. Thereby, when the paper cassette 11 is opened or closed before a new job is started, it is possible to perform processing in the default automatic detection mode that is easy to use even for users with little knowledge about the sheet type.

[0100] [Modification Example] Note that the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be appropriately changed without departing from the gist of the present invention.

[0101] For example, in the above-described first embodiment, as processing related to switching of the mode when setting the sheet type, a case where it is determined whether to switch from the type designation mode to the automatic discrimination mode according to the type of the sheet S specified by the user is shown. Also, in the second embodiment, a case where it is determined whether to switch from the type designation mode to the automatic discrimination mode according to the status of the image forming job is shown. However, the content shown in the first embodiment and the content shown in the second embodiment do not conflict with each other. For example, it may be determined whether to switch the mode when setting the sheet type by combining both of them.

[0102] Also, various settings by the user are not limited to those input from the operation display unit 105 of the image forming apparatus 100. For example, they may be input and set from various terminal devices and the like connected to the image forming apparatus 100 via a communication network.

[0103] In addition, in this embodiment, for example, in FIGS. 7A and 7B, etc., the case where the user sets the validity of the automatic detection mode and the type designation mode has been described. However, the validity of the automatic detection mode and the type designation mode may be set by the administrator who manages the image forming apparatus 100. Moreover, it may have an administrator mode in which only the administrator can set the validity of the automatic detection mode and the type designation mode, and a user mode in which the user can set it.

[0104] FIG. 13 is an example of a screen showing an administrator setting screen for the administrator to perform various settings. For example, in the administrator setting screen 115c shown in FIG. 13, the setting of sheet type automatic detection (``paper type automatic detection'' in FIG. 13) can be performed for each paper cassette 11 (``tray'' in FIG. 13). That is, the administrator setting screen 115c is provided with a switch 164 for switching the ON / OFF of the sheet type automatic detection for each paper cassette 11 (``tray'' in FIG. 13). If the switch 164 is moved to the left, the sheet type automatic detection becomes OFF. Also, if the switch 164 is moved to the right, the sheet type automatic detection becomes ON. In the illustrated example, the sheet type automatic detection is set to ON for all the paper cassettes 11.

[0105] In addition, the administrator setting screen 115c is provided with a cancel button 165 for canceling the setting and an OK button 166 for approving the setting, so that the settings on the administrator setting screen 115c can be canceled or approved collectively. Note that on the administrator setting screen 115c, in addition to the setting of the sheet type automatic detection, various settings such as the initial setting of the operation screen can be performed. By allowing the administrator to perform various settings, it becomes possible to uniformly perform various settings according to the environment in which the image forming apparatus is used.

[0106] In addition, the configuration and operation of the image forming apparatus 100 can be appropriately changed without departing from the spirit of the present invention.

Description of Reference Numerals

[0107] 11 Paper Cassette 12 Conveyor Roller 13 Registration Roller 20 Media Detection Sensor 30 Process Unit 31 Photoconductor Drum 41 Intermediate Transfer Belt 44 Primary Transfer Roller 45 Secondary Transfer Roller 50 Fixing Device 101 Sheet Feeding Means 102 Image Forming Unit 105 Operation Display Unit 108 Control Unit 109 Memory Unit 111 Opening / Closing Detection Means 115 Display Panel 100 Image Forming Apparatus R Conveyor Path S Sheet

Claims

1. Supply means for supplying a sheet, Sheet type discrimination means for discriminating the type of the sheet supplied by the supply means, Sheet type designation reception means for receiving the designation of the sheet type by the user, An automatic detection mode in which an image is formed on the supplied sheet in the type of sheet discriminated by the sheet type discrimination means, and a type designation mode in which an image is formed on the supplied sheet in the type of sheet received by the sheet type designation reception means, and image forming means for performing image formation in any one of the modes, Mode setting means for determining and setting in which mode the image forming means performs image formation, Switching determination means for determining whether to switch the mode set by the mode setting means, Switching means for automatically switching the mode when the image forming means forms an image when it is determined by the switching determination means that the mode is to be switched, Detection means for detecting at least one of an operation of opening or closing a paper cassette for accommodating a sheet by a user operation, comprising, When the type designation mode is set by the mode setting means, the switching determination means determines whether to switch the mode from the type designation mode to the automatic detection mode based on the detection of at least one of the opening operation or the closing operation by the detection means. An image forming apparatus characterized by that.

2. Having a display panel and comprising display means for notifying the user of various device states and messages, The image forming apparatus according to claim 1, wherein when switching between the automatic detection mode and the type designation mode, it is displayed on the display panel.

3. The determination as to whether the switching determination means switches the mode is made according to the type of sheet designated in the type designation mode when at least one of the opening operation or the closing operation of the paper cassette is detected by the detection means. The image forming apparatus according to claim 1, characterized by that.

4. When the sheet designated in the type designation mode is a sheet that cannot be discriminated by the sheet type discrimination means, the switching determination means determines to maintain the type designation mode without switching the mode. The image forming apparatus according to claim 3, characterized by that.

5. The image forming apparatus according to claim 3, wherein when the sheet specified in the type designation mode is a sheet that can be discriminated by the sheet type discrimination means, the switching determination means determines to switch the type designation mode to the automatic detection mode.

6. The determination by the switching determination means as to whether or not to switch the mode is performed according to the operation state of the image forming job when at least one of the operations of opening or closing the paper cassette is detected by the detection means. The image forming apparatus according to claim 1, characterized in that.

7. When at least one of the operations of opening or closing the paper cassette is detected by the detection means during a series of image forming jobs, the switching determination means determines to maintain the type designation mode without switching the mode. The image forming apparatus according to claim 6, characterized in that.

8. When at least one of the operations of opening or closing the paper cassette is detected by the detection means when there are no image forming jobs in the standby and accepted states, the switching determination means determines to maintain the type designation mode without switching the mode. The image forming apparatus according to claim 6, characterized in that.

9. The image forming apparatus according to claim 1, further comprising an administrator mode in which only an administrator can set the validity / invalidity of the automatic detection mode and the type designation mode, and a user mode in which a user can set the validity / invalidity.

10. The image forming apparatus according to claim 2, wherein when a message is displayed on the display panel for a setting change for switching between the automatic detection mode and the type designation mode, a plurality of message display methods are provided.

11. The message display displayed on the display panel is only for prompting a setting change to the automatic detection mode, The image forming apparatus according to claim 10, wherein the switching means does not switch the mode when the image forming means forms an image unless a user gives an instruction to change the setting.

12. The message display displayed on the display panel notifies a forced setting change to the automatic detection mode, The image forming apparatus according to claim 10, wherein the switching means forcibly switches the mode to the automatic detection mode when the image forming means forms an image.

13. After the setting is changed to the automatic detection mode, it is possible to select to return to the original setting again. The image forming apparatus according to claim 10, wherein when the selection to return to the original setting is made again, the setting change is not redisplayed on the display panel.

14. The sheet type discriminating means includes measuring means for irradiating light to a sheet and measuring the physical properties of the sheet based on the transmittance and reflectance of the irradiated light, and discriminates the type of the sheet based on the measurement result by the measuring means. The image forming apparatus according to claim 1.

15. A sheet type discrimination step of discriminating the type of the sheet supplied by the supply means, A sheet type designation reception step of receiving a designation of the type of the sheet by the user, An automatic detection mode of forming an image on the supplied sheet with the type of the sheet discriminated in the sheet type discrimination step, and a type designation mode of forming an image on the supplied sheet with the type of the sheet received in the sheet type designation reception step. An image forming step of forming an image in any one of the modes, A mode setting step of determining and setting which mode to form an image in the image forming step, A switching determination step of determining whether or not to switch the mode set in the mode setting step, A switching step of automatically switching the mode for forming an image in the image forming step when it is determined in the switching determination step that the mode is to be switched, A detection step of detecting at least one of an operation of opening or closing a paper cassette for accommodating sheets by a user operation, Comprising The switching determination step determines whether or not to switch the mode from the type designation mode to the automatic detection mode based on the fact that at least one of the opening operation or the closing operation is detected in the detection step when the type designation mode is set in the mode setting step. An image forming method characterized by the above.

16. In a computer, A sheet type discrimination function for discriminating the type of the sheet supplied by the supply means, A sheet type designation reception function for receiving a designation of the type of the sheet by the user, An image forming function that forms an image on the supplied sheet in either an automatic detection mode in which the image is formed in the type of sheet determined by the sheet type discrimination function, or a type designation mode in which the image is formed in the type of sheet received by the sheet type designation reception function; A mode setting function that determines and sets in which mode the image is formed by the image forming function; A switching determination function that determines whether or not to switch the mode set by the mode setting function; A switching function that automatically switches the mode at the time of image formation by the image forming function when it is determined by the switching determination function that the mode is to be switched; A detection function that detects at least one of an operation of opening or closing a paper cassette that houses sheets by a user operation; is realized, The switching determination function determines whether or not to switch the mode from the type designation mode to the automatic detection mode based on at least one of the opening operation or the closing operation being detected by the detection function when the type designation mode is set by the mode setting function. A program characterized by that.

Images