Image forming apparatus

Abstract

To shorten the time it takes for the image forming apparatus to become usable after it has been started up. [Solution] The image forming apparatus includes a tray for holding a cartridge containing toner, a moving means for moving the tray within a range including a first position and a second position, and a control means for controlling the movement of the tray by controlling the moving means, and for determining whether or not to perform position determination control to move the tray to the first position or the second position based on tray information including tray position information relating to the position of the tray when the image forming apparatus is started.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet. Background Art

[0002] Patent Document 1 discloses an image forming apparatus in which a toner cartridge accommodating toner is mounted, via a tray, on a rotationally driven rotary body. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2024-068631 Summary of the Invention Problems to be Solved by the Invention

[0004] In Patent Document 1, the tray is configured to be movable between an accommodation position and an extraction position. The accommodation position is a position at which the toner of the toner cartridge held on the tray can be supplied to a developing section. The extraction position is a position at which the toner cartridge held on the tray can be replaced. Patent Document 1 discloses that the tray is moved by receiving the driving force of a driving device.

[0005] In order for the driving device to correctly operate the tray, it is preferable that the image forming apparatus performs an operation for determining the position of the tray. On the other hand, the image forming apparatus cannot perform an image forming operation until the operation for determining the position of the tray is completed.

[0006] The present invention provides a technique for shortening the time until the image forming apparatus becomes ready for use when the image forming apparatus is activated. Means for Solving the Problems

[0007] According to one aspect of the present invention, an image forming apparatus includes a tray for holding a cartridge containing toner, a moving means for moving the tray within a range including a first position and a second position, and a control means for controlling the movement of the tray by controlling the moving means, and for determining whether or not to perform position determination control to move the tray to the first position or the second position based on tray information including tray position information relating to the position of the tray when the image forming apparatus is started. [Effects of the Invention]

[0008] According to the present invention, the time it takes for an image forming apparatus to become usable after it has been started can be shortened. [Brief explanation of the drawing]

[0009] [Figure 1] Cross-sectional view of an image forming apparatus. [Figure 2] Cross-sectional view of the cartridge and developing unit. [Figure 3] Cross-section of a rotary tiller. [Figure 4] External view of the rotary tiller. [Figure 5] Diagram illustrating the cartridge replacement procedure. [Figure 6] Cross-sectional view of the rotary mechanism during cartridge replacement. [Figure 7] A perspective view showing the tray arrangement within the rotary. [Figure 8] A cross-sectional view showing the tray arrangement within the rotary. [Figure 9] A perspective view showing the drive configuration of the tray. [Figure 10] A cross-sectional view showing the drive configuration of the tray. [Figure 11] A diagram showing an example of a tray position detection configuration and the output signal of a photointerrupter. [Figure 12] A diagram showing another example of a tray position detection configuration. [Figure 13] A diagram showing an example of the control configuration of an image forming apparatus. [Figure 14] A diagram showing an example of tray information. [Figure 15] A flow chart illustrating an example of tray information management processing. [Figure 16] A flow chart illustrating an example of initial processing. [Figure 17] A diagram illustrating an example of control content information. MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of the plurality of features are necessarily essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0011] <First Embodiment> (Overall Configuration of Image Forming Apparatus) An image forming apparatus according to the present embodiment will be described. Here, as an image forming apparatus including a plurality of developing units, a color laser beam printer including four developing units is exemplified.

[0012] A schematic configuration and an image forming operation of the color laser beam printer will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of the color laser beam printer.

[0013] As shown in FIG. 1, an image forming apparatus main body 1 includes a drum-shaped electrophotographic photoreceptor 2 (hereinafter referred to as a photoreceptor drum 2). Around the photoreceptor drum 2, a charging roller 3, an exposure device 4, four developing units 5a to 5d, and a cleaning unit 6 are arranged. The charging roller 3 is a charging member for uniformly charging the photoreceptor drum 2. The exposure device 4 is an exposure unit that irradiates the photoreceptor drum 2 with laser light corresponding to image information. An electrostatic latent image is formed on the photoreceptor drum 2 by irradiating the charged photoreceptor drum 2 with the laser light. The developing units 5a to 5d are developing units that develop the electrostatic latent image formed on the photoreceptor drum 2 with toner of a corresponding color to visualize the latent image. The cleaning unit 6 is a cleaning member that removes toner remaining on the surface of the photoreceptor drum 2.

[0014] The developing units 5a to 5d include developing rollers 51a to 51d. Furthermore, cartridges 7a to 7d that accommodate toner, which is a color material, are mounted to the developing units 5a to 5d. The cartridges 7a to 7d respectively accommodate yellow, magenta, cyan, and black toner. The developing units 5a to 5d respectively develop the electrostatic latent image formed on the photoreceptor drum 2 with yellow, magenta, cyan, and black toner. Here, the four developing units 5a to 5d are provided on a rotary 9 that is a rotatable rotation support body. Furthermore, trays 8a to 8d are provided on the rotary 9, and the cartridges 7a to 7d are detachably held by the trays 8a to 8d. As will be described later, the trays 8a to 8d are supported so as to be slidable to the outside (attachment / detachment position) of the rotary 9. By sliding the trays 8a to 8d (and the cartridges 7a to 7d held by the trays 8a to 8d) to the attachment / detachment position, the cartridges 7a to 7d are configured to be attachable and detachable from the rotary 9.

[0015] The "a," "b," "c," and "d" at the end of the reference numerals are used to distinguish the color of the toner image formed by the component indicated by that reference numeral. In the following explanation, when it is not necessary to distinguish the color of the toner image formed by a component, the reference numerals without the "a," "b," "c," and "d" at the end will be used collectively.

[0016] Figure 2 is a conceptual diagram showing the configuration for supplying toner from cartridge 7 to the developing unit 5. The toner frame 71 of cartridge 7 includes a toner storage section 710 and an discharge opening 711 communicating with the toner storage section 710. The developing frame 53 of the developing unit 5 includes a developing-side storage section 530 and a receiving opening 531 communicating with the developing-side storage section. As will be described later, when cartridge 7 is moved to the storage position, the discharge opening 711 faces the receiving opening 531. When toner is supplied from cartridge 7 to the developing unit 5, at least a part of the receiving opening 531 is positioned below at least a part of the discharge opening 711. Then, the toner stored in the toner storage section 710 is discharged from the discharge opening 711, and the toner discharged from the discharge opening 711 enters the developing-side storage section 530 through the receiving opening 531. It is desirable that cartridge 7 has a toner-side sealing member (not shown) that covers the discharge opening 711. Furthermore, it is desirable that the developing unit 5 has a developing-side sealing member (not shown) that covers the receiving opening 531. When the cartridge 7 is not installed in the developing unit 5, it is desirable that the discharge opening 711 is covered by the toner-side sealing member and the receiving opening 531 is covered by the developing-side sealing member so that the discharge of toner from the discharge opening 711 and the receiving opening 531 is suppressed.

[0017] (Image forming operation of an image forming apparatus) The image formation operation in this embodiment will be explained using Figure 1. First, the photoreceptor drum 2 is rotated in the direction of the arrow in Figure 1 (counterclockwise) in synchronization with the rotation of the intermediate transfer belt 10. Then, the surface of the photoreceptor drum 2 is uniformly charged by the charging roller 3. At the same time, the exposure unit 4 irradiates the photoreceptor drum 2 with laser light to form an electrostatic latent image for the yellow toner image on the photoreceptor drum 2.

[0018] Prior to the formation of this electrostatic latent image, a rotary support, the rotary 9, is rotated to stop the yellow developing unit 5a in a developing position facing the photoreceptor drum 2. In the developing position, the developing roller 51a provided on the yellow developing unit 5a is in contact with the photoreceptor drum 2, and the electrostatic latent image is developed with yellow toner. That is, the rotary 9 supports the developing units 5a to 5d and rotates in the direction of the arrow in Figure 1 (clockwise), sequentially moving the four supported developing units 5a to 5d one by one to the developing position facing the photoreceptor drum 2. The developing unit located in the developing position develops the electrostatic latent image formed on the photoreceptor drum 2 according to the color of the toner it contains.

[0019] After developing the electrostatic latent image, the yellow toner formed on the photoreceptor drum 2 is first transferred to the intermediate transfer belt 10 by the primary transfer roller 11 located inside the intermediate transfer belt 10. Then, the magenta, cyan, and black developing units 5a to 5d are sequentially rotated by the rotation of the rotary 9 and stop at the developing position facing the photoreceptor drum 2. Then, in the same manner as with yellow, the formation of the electrostatic latent image, development, and primary transfer are sequentially performed for each of the magenta, cyan, and black colors. In this way, the toner images of the four colors are superimposed on the intermediate transfer belt 10.

[0020] During this time, the secondary transfer roller 12 is not in contact with the intermediate transfer belt 10. Also, at this time, the cleaning device 13 that removes residual toner from the intermediate transfer belt 10 is not in contact with the intermediate transfer belt 10.

[0021] Meanwhile, the sheets S, which serve as recording media, are loaded and stored in a sheet storage section 300 located at the bottom of the main body of the image forming apparatus 1. The sheets S are fed by a pick roller 310, separated one by one by a feed roller 311 and a separation roller 312, and then sent to a transport roller pair 320. The transport roller pair 320 feeds the sheets S to the intermediate transfer belt 10 and the nip portion of the secondary transfer roller 12. The four superimposed toner images on the intermediate transfer belt 10 are transferred (secondary transfer) all at once to the surface of the transported sheets S.

[0022] The sheet S onto which the toner image has been transferred is sent to the fuser unit 40. In the fuser unit 40, the sheet S is heated and pressurized, and the toner image is fixed onto the sheet S. As a result, a color image is formed on the sheet S. The sheet S is then discharged from the fuser unit 40.

[0023] (Rotary configuration) The configuration of the rotary 9 will be explained using Figures 3 and 4. Figure 3 is a cross-sectional view of the rotary 9. Figure 4 is an external view of the rotary 9. As mentioned above, the cartridge 7 is detachable from the rotary 9, and when the toner in the cartridge 7 runs out, the user can replace the cartridge 7. When the cartridge 7 is replaced, the rotary 9 stops at the cartridge 7 replacement position.

[0024] Figure 3(a) shows a cross-section of the rotary tiller 9 when stopped in the developing position. Figure 3(b) shows a cross-section of the rotary tiller 9 when stopped in the replacement position. As shown in Figures 3(a) and (b), four trays 8a to 8d are arranged inside the rotary tiller 9, and cartridges 7a to 7d are held in each of the trays 8a to 8d. At this time, cartridges 7a to 7d are mounted in the developing units 5a to 5d. In this embodiment, cartridge 7d, which contains black toner, is larger in size than cartridges 7a to 7c, which contain other color toners, and can hold more toner. Therefore, tray 8d, which holds cartridge 7d, is larger in size than trays 8a to 8c, which hold cartridges 7a to 7c. In other words, four cartridges 7a to 7d and trays 8a to 8d of different sizes are arranged inside the rotary tiller 9.

[0025] The rotary tiller 9 is supported so as to be able to swing around a pivot axis 91. In the developing position, the developing roller 51 is in contact with the photoreceptor drum 2 due to biasing by a biasing member (not shown). In the process of rotating the rotary tiller 9 clockwise in the figure to move the cartridge 7 to the replacement position, the rotary tiller 9 swings around the pivot axis 91 by a separation mechanism (not shown), and the developing roller 51 separates from the photoreceptor drum 2. In the replacement position, the cartridge 7 is stopped in a position facing the door 14 located on the front of the image forming apparatus body 1. In this state, the user can replace the cartridge 7 by sliding the tray 8 from the storage position to the attachment / detachment position in the developing unit 5. The cartridge replacement operation will be described later.

[0026] The rotational drive of the rotary 9 will be explained using Figure 4. As shown in Figure 4, disc gears 92a and 92b are formed at both ends of the rotary 9. In addition, rotary drive gears 93a and 93b are connected to both ends of the oscillating shaft 91 in a manner that allows for power transmission. Here, the driving force of the rotary drive gears 93a and 93b is transmitted to the disc gears 92a and 92b, causing the rotary 9 to rotate.

[0027] (Cartridge replacement operation) The operation of the image forming apparatus when replacing cartridge 7 will be explained using Figures 5 and 6. Figure 5 is an external view of the main body 1 of the image forming apparatus. Figure 6 is a cross-sectional view of the rotary during cartridge replacement.

[0028] Figure 5(a) shows the external appearance of the image forming apparatus body 1 during image forming operation and in standby mode. At this time, the door 14 is closed. Figure 5(b) shows the external appearance of the image forming apparatus body 1 when a cartridge is being replaced. At this time, the door 14 is open, and the tray 8 and cartridge 7 have moved to the loading / unloading position.

[0029] First, when the user instructs the image forming apparatus body 1 to replace a cartridge (for example, by pressing the replacement button), the rotary 9 rotates to the replacement position for the cartridge 7 to be replaced (the cartridge 7 that has run out of toner) and stops. Next, the tray 8 and cartridge 7 slide from the storage position to the attachment / detachment position in the developing unit 5. The door 14 is rotatably supported relative to the image forming apparatus body 1, and the sliding movement of the tray 8 causes the door 14 to open (as shown in Figure 5(b)). Here, since the cartridge 7 is detachably held in the tray 8, as shown in Figure 5(c), the user can perform the replacement by removing the cartridge 7 from the tray 8 and attaching a new cartridge 7. Note that if multiple cartridges 7 need to be replaced, the above operation can be repeated to perform the replacement.

[0030] Figure 6 shows a cross-section of the rotary 9 during cartridge replacement. As shown in Figure 6, when replacing a cartridge, it is desirable that the entire cartridge 7 protrudes from the front of the image forming apparatus body 1, as the user performs the operation of attaching and detaching the cartridge 7 from the tray 8.

[0031] (Tray arrangement within the rotary) The arrangement of trays 8a to 8d within the rotary 9 will be explained using Figures 7 and 8. Figure 7 is a perspective view showing the arrangement of trays 8a to 8d within the rotary 9. Figure 8 is a cross-sectional view showing the arrangement of trays 8a to 8d within the rotary 9.

[0032] As shown in Figure 7, trays 8a to 8b are provided with cartridge holding sections 81a to 81b and tray rails 82a to 82d, respectively. The tray rails 82a to 82d are provided at both ends of the cartridge holding sections 81a to 81d. Rack sections 821a to 821d are formed on the tray rails 82a to 82d. In addition, rack gears 94a to 94d are rotatably held within the rotary 9, and the rack gears 94a to 94d are meshed with the rack sections 821a to 821d so as to transmit power.

[0033] Furthermore, as shown in Figures 7 and 8, four trays 8a to 8d are arranged overlapping within the rotary 9. The insertion and removal directions for each tray are rotated by 90 degrees (indicated by the arrows in the figures). Therefore, trays 8a and 8c, and trays 8b and 8d are held in a position to slide in the same direction.

[0034] (Tray insertion / removal drive configuration) The drive configuration of trays 8a to 8d arranged within the rotary 9 will be explained using Figures 9 and 10. Figure 9 is a perspective view showing the drive configuration of tray 8. Figure 10 is a cross-sectional view showing the drive configuration of tray 8.

[0035] Figure 9(a) shows the tray 8d inside the rotary 9 (i.e., the cartridge 7d is mounted on the developing unit 5d). Figure 9(b) shows the tray 8d slid into the attachment / detachment position. As mentioned above, two rack sections 821d are formed at both ends. Also, two rack gears 94d and two drive racks 15 are positioned at the locations corresponding to the rack sections 821d at both ends. The tray 8d is held so as to be slidable relative to the rotary 9 in a direction parallel to the tray rail 82d. The drive rack 15 is held so as to be slidable vertically relative to the image forming apparatus body 1. Here, only tray 8d is shown among the four trays 8a to 8d, but the drive configuration of the other trays 8 is similar.

[0036] Using Figures 10(a) and (b), the tray insertion and removal operation, in which the tray 8d is slid from the inside (storage position) to the outside (attachment / detachment position) of the rotary 9, will be explained. The insertion and removal operation of the tray 8d is performed by the drive source 20 (see Figures 11 and 12), the drive rack 15, the rack gear 94d, and the rack section 821d. First, the drive force transmitted by the drive source 20 causes the drive rack 15 to slide upward on the main body 1 of the image forming apparatus, transmitting the drive to the rack gear 94. The rack gear 94d rotates counterclockwise, transmitting the drive to the rack section 821d, causing the tray 8d to slide from the storage position of the cartridge 7d to the attachment / detachment position on the developing unit 5d.

[0037] Furthermore, after cartridge replacement, the operation of sliding tray 8d into the rotary 9 (storage position) can be performed by rotating the drive source 20 in the opposite direction to when sliding tray 8d out of the rotary 9 (attachment / detachment position). In this case, the drive rack 15 slides downwards on the image forming apparatus body 1, causing tray 8d to be pulled into the rotary 9.

[0038] As described above, the tray 8 located inside the rotary 9 can be moved by rotating the drive source 20 in forward and reverse directions. Thus, the drive source 20 can also be referred to as the moving part that moves the tray 8. Alternatively, the drive unit 20, the drive rack 15 that transmits the driving force of the drive unit 20 to the tray 8, the rack gear 94, and the rack unit 821 can all be referred to as the moving part that moves the tray 8.

[0039] (The driving operation of the drive source during tray movement) The driving operation of the drive source 20 will be explained using Figures 11 and 12. Figure 11(a) is a perspective view of the vicinity of the drive source 20, Figure 11(b) is a top view of the vicinity of the drive source 20, and Figure 11(c) shows the output signal of the photointerrupter 30 accompanying the movement of the tray 8. In Figures 11 and 12, the y direction is parallel to the direction of the rotation axis of the rotary body 90. The z direction is vertical. The x direction is horizontal and is perpendicular to the y and z directions. The direction of movement of the tray 8 when moving between the attachment / detachment position and the storage position is a direction that intersects the z and y directions. In this embodiment, the direction of movement of the tray 8 is parallel to the x direction.

[0040] A slider 25 is connected to the drive source 20. In this embodiment, the slider 25 is connected to the drive source 20 via at least one gear. Also, as shown in Figure 11(a), the slider 25 transmits the driving force of the drive source 20 to the drive rack 15.

[0041] The encoder rack 28 is connected to the slider 25 via a gear. The slider 25 is connected to a sector gear, and further equipped with a stepped gear that meshes with the encoder rack 28. In Figure 11(b), when the slider 25 moves in the +y direction (left in the figure), the sector gear, one end of which is connected to the slider 25, rotates counterclockwise in the figure. As a result, the stepped gear rotates clockwise, and the encoder rack 28 moves in the +y direction (left in the figure). The reverse operation occurs when the slider 25 moves in the -y direction (right in the figure).

[0042] As described above, the drive rack 15, slider 25, and encoder rack 28 are moved by the driving force of the drive source 20. Therefore, the slider 25 and encoder rack 28 move in conjunction with the movement of the tray 8. The slider 25 and encoder rack 28 are examples of moving members that move in the y-direction. More specifically, the slider 25 and encoder rack 28 are examples of moving members that move linearly in the y-direction.

[0043] In this embodiment, the range of movement of the encoder rack 28 is greater than the range of movement of the slider 25. In other words, the number of teeth that mesh with the encoder rack 28 is greater than the number of teeth that mesh with the sector gear.

[0044] The encoder rack 28 is intermittently provided with openings 29, and photointerrupters 30 are positioned at the locations where the openings 29 move as the encoder rack 28 moves. When the opening 29 enters the detection position of the photointerrupter 30, the output signal switches from a low state (LOW) to a high state (HIGH), and when the opening 29 leaves the detection position of the photointerrupter 30, the output signal switches from HIGH to LOW. This is how the circuit (not shown) is configured.

[0045] Therefore, when tray 8 begins to move from the storage position to the attachment / detachment position, the output signal switches from LOW to HIGH, and while tray 8 is moving, HIGH and LOW are repeatedly output, and when the movement to the attachment / detachment position is completed, the output signal becomes constant at LOW.

[0046] When the CPU 1307 (see Figure 13) drives the drive source 20 to start moving the tray 8 to the loading / unloading position, it monitors the output signal. The CPU 1307 determines that the tray 8 is moving if the duration of the HIGH or LOW output signal is less than a certain period of time, and continues to drive the drive source 20. Then, when the output signal switches from HIGH to LOW, and then LOW is output for a certain period of time, the CPU 1307 determines that the movement of the tray 8 to the loading / unloading position is complete, and stops driving the drive source 20.

[0047] Similarly, when tray 8 begins to move from the attachment / detachment position to the storage position, the output signal switches from LOW to HIGH, and while tray 8 is moving, HIGH and LOW are repeatedly output, and when the movement to the storage position is complete, the output signal becomes constant at LOW.

[0048] When the CPU 1307 drives the drive source 20 to start moving the tray 8 to its storage position, it monitors the output signal. Note that the direction of drive of the drive source 20 when moving the tray 8 to the storage position is the opposite direction to the direction of drive of the drive source 20 when moving the tray 8 to the attachment / detachment position. The CPU 1307 determines that the tray 8 is moving and continues to drive the drive source 20 if the duration of the HIGH or LOW output signal is less than a certain period of time. Then, when the output signal switches from HIGH to LOW, and then LOW is output for a certain period of time, the CPU 1307 determines that the movement of the tray 8 to its storage position is complete and stops driving the drive source 20.

[0049] As described above, the CPU 1307 can determine the direction of movement of the tray 8 and the completion of movement to the storage position or attachment / detachment position of the tray 8 from the driving direction of the drive source 20 and the output signal of the photo interrupter 30.

[0050] Furthermore, the CPU 1307 can count the number of changes in the output signal while tray 8 is moving, that is, the number of times it switches from HIGH to LOW and the number of times it switches from LOW to HIGH. The CPU 1307 can also determine the position of tray 8 and whether tray 8 has moved to the storage position or the loading / unloading position by comparing the total number of changes in the output signal during movement from the loading / unloading position to the storage position (hereinafter referred to as the reference number of changes) with the number of changes it has counted. The position of tray 8 corresponds, for example, to the distance from the storage position or the loading / unloading position.

[0051] Furthermore, if the output signal remains HIGH for a certain period of time or longer, the CPU 1307 can determine that tray 8 has stopped moving.

[0052] Although the description above explains the case where the detection unit of the photointerrupter 30 is formed on the encoder rack 28, which has a greater range of movement than the slider 25, in order to improve detection accuracy, it is also possible to form the detection unit of the photointerrupter 30 on the slider 25.

[0053] Furthermore, although the output signal is assumed to be HIGH while the aperture 29 is at the detection position of the photointerrupter 30, the configuration may also be such that the output signal is LOW while the aperture 29 is at the detection position of the photointerrupter 30.

[0054] Furthermore, as shown in Figure 12, it is also possible to form the detection unit of the photointerrupter 30 on the encoder 33 connected to the drive source 20. Figure 12 is a perspective view of the vicinity of the drive source 20. The encoder 33 is connected to the drive source 20 via a gear, and the photointerrupter 30 is positioned so as to sandwich the encoder 33. The encoder 33 is provided with a plurality of openings 33a and 33b, of which at least one opening 33b is wider than the other openings 33a. When the tray 8 is in the storage position and the attachment / detachment position, the opening 33b is configured to be in a position that the photointerrupter 30 can detect.

[0055] In this way, it is possible to determine from the driving direction of the drive source 20 and the signal from the photo interrupter 30 whether the tray 8 has completed moving to the storage position or to the attachment / detachment position. It is desirable that the number of encoder rotations during the movement of the tray 8 from the storage position to the attachment / detachment position be 1 rotation or less.

[0056] (Control configuration of an image forming apparatus) Figure 13 shows an example of a control configuration for an image forming apparatus. Controller 1302 controls the entire image forming apparatus. Controller 1302 includes, for example, one or more processors and one or more memory devices. One or more memory devices may include volatile memory and non-volatile memory. One or more processors control the entire image forming apparatus by executing control programs stored in one or more memory devices. One or more memory devices may also store control data used by one or more processors to control the image forming apparatus.

[0057] The controller 1302 may be configured to communicate with a host computer 1301 outside the image forming apparatus via a network. When the controller 1302 receives a print instruction from the host computer 1301, it causes the engine control unit 1303 to form an image based on the print data received along with the print instruction.

[0058] The control unit 1304 includes an input interface for the user to operate the image forming apparatus and an output interface for displaying the status of the image forming apparatus to the user. The input interface may include, for example, a push button for operating the replacement of the cartridge 7. The output interface may include, for example, an LED (light-emitting diode) to indicate that an abnormality has occurred in the cartridge replacement operation. The input interface and the output interface may also be touch panels.

[0059] For example, when a user inputs a command to replace cartridge 7 via the operation unit 1304, the controller 1302 instructs the engine control unit 1303 to move the tray 8 holding the cartridge 7 to be replaced to the attachment / detachment position. As a result, the engine control unit 1303 rotates the rotary 9 to the replacement position of the cartridge 7 to be replaced, and then moves the tray 8 holding the cartridge 7 to be replaced from the storage position to the attachment / detachment position. Also, when a user inputs the completion of cartridge 7 replacement via the operation unit 1304, the controller 1302 instructs the engine control unit 1303 to move the tray 8 from the attachment / detachment position to the storage position. As a result, the engine control unit 1303 moves the tray 8 from the attachment / detachment position to the storage position.

[0060] In the following description, the action of moving tray 8 from the storage position to the attachment / detachment position will be referred to as "drawing out" tray 8, and its control will also be referred to as "drawing out control." Similarly, the action of moving tray 8 from the attachment / detachment position to the storage position will be referred to as "retracting in" tray 8, and its control will also be referred to as "retracting in control." Furthermore, the draw-out control and retracting control of tray 8 will be collectively referred to as "movement control."

[0061] Furthermore, the image forming apparatus may also be configured so that a user can operate the image forming apparatus via a host computer 1301. In this case, the host computer 1301 functions as an operating unit for the user.

[0062] The engine control unit 1303 includes a CPU (Central Processing Unit) 1307 containing one or more processors, a non-volatile memory 1308, and a volatile memory 1309. The non-volatile memory 1308 stores the control program executed by the CPU 1307. The non-volatile memory 1308 is also used to store the control data that the CPU 1307 uses for its control. The volatile memory 1309 is used to store data that the CPU 1307 must temporarily maintain in its control.

[0063] Furthermore, some or all of the processes described below, which are performed by the CPU 1307, may be performed by hardware such as application-specific integrated circuits (ASICs) or programmable devices such as field-programmable gate arrays (FPGAs).

[0064] When the CPU 1307 receives an instruction from the controller 1302 to perform image formation, it controls each component shown in Figure 1 to form an image on the sheet S as explained using Figure 1. Furthermore, when the CPU 1307 receives an instruction from the controller 1302 to move the tray 8 to its attachment / detachment position, it controls the rotation of the rotary 9 and the withdrawal of the tray 8. Additionally, when the CPU 1307 receives an instruction from the controller 1302 to move the tray 8 to its storage position, it controls the retraction of the tray 8. The rotary drive source 32 shown in Figure 13 is the drive source for rotating the rotary 9. The CPU 1307 controls the rotation of the rotary 9 by controlling the rotary drive source 32.

[0065] Furthermore, as explained using Figures 11 and 12, the CPU 1307 controls the movement of the tray 8 by controlling the drive source 20. In addition, as explained using Figures 11 and 12, the CPU 1307 determines the position of the tray 8 based on the output signal of the photointerrupter 30 in controlling the movement of the tray 8. The output signal of the photointerrupter 30 indicates the detection result of a plurality of openings provided in a member configured to move in conjunction with the movement of the tray 8. In the following description, the photointerrupter 30, the member provided with these plurality of openings, and its movement mechanism are collectively referred to as the position sensor 31. The position sensor 31 is also referred to as the output unit (output means, output unit) that outputs an output signal for the CPU 1307 to determine the position of the tray 8. In other words, the position sensor 31 includes an encoder rack 28 as a detected part that moves in conjunction with the tray 8, and a photointerrupter 30 as a sensor part that outputs an output signal that changes according to the movement of the detected part. As the encoder rack 28 moves, the output signal of the photointerrupter 30 changes between HIGH and LOW. As mentioned above, a slider 25 may be used as the detected part.

[0066] (Tray information) Figure 14 shows an example of tray information that the CPU 1307 stores in the non-volatile memory 1308 regarding the movement state of tray 8. The tray information is recorded for tray 8 that is in a state where it can move between the storage position and the attachment / detachment position, depending on the rotation state of the rotary 9. The tray information may include tray position information, state information, and signal change information. The tray position information is information about the position of tray 8 and stores one of the following: "storage position", "attach / detachment position", "pulling out", or "retracting".

[0067] When CPU 1307 moves tray 8 to the storage position, it sets the tray position information to "storage position". When CPU 1307 moves tray 8 to the attachment / detachment position, it sets the tray position information to "attachment / detachment position". While CPU 1307 is moving tray 8 toward the attachment / detachment position by the pull-out control, it sets the tray position information to "pulling out". While CPU 1307 is moving tray 8 toward the storage position by the retraction control, it sets the tray position information to "retracting". The tray position information being "pulling out" or "retracting" indicates that tray 8 is moving and is located between the storage position and the attachment / detachment position. Furthermore, the tray position information being "pulling out" indicates that the direction of movement of the tray in the movement control is toward the attachment / detachment position (pulling direction), and the tray position information being "retracting" indicates that the direction of movement of the tray in the movement control is toward the storage position (retraction direction). In the following explanation, the position between the storage position and the attachment / detachment position will also be referred to as the "intermediate position". The intermediate position can also be defined as any position between the storage position and the attachment / detachment position.

[0068] The status information pertains to the movement control status of tray 8 and can be set to one of the following: "Normal", "Abnormal Stop (External Factor)", or "Abnormal Stop (Internal Factor)". "Normal" indicates that there is no abnormality in the movement control of tray 8. The initial value of the status information is "Normal". "Abnormal Stop (External Factor)" and "Abnormal Stop (Internal Factor)" indicate that the movement control of tray 8 has been stopped due to an abnormality in the movement control of tray 8.

[0069] "Abnormal Stop (Internal Factor)" indicates that the movement control was stopped due to a malfunction of a component of the image forming apparatus, such as a malfunction of the drive source 20, a malfunction of the gear that transmits the driving force of the drive source 20, or a malfunction of the position sensor 31. On the other hand, "Abnormal Stop (External Factor)" indicates that the movement control was stopped for a reason other than a malfunction of a component of the image forming apparatus, such as a user error. For example, "Abnormal Stop (External Factor)" is recorded when the tray 8 cannot be moved to the attachment / detachment position due to the presence of an obstacle near the door 14. As another example, "Abnormal Stop (External Factor)" is recorded when the tray 8 cannot be moved to the storage position because the user did not properly attach the cartridge 7 to the tray 8.

[0070] The signal change information indicates the count value of the number of times the output signal has changed. The number of changes includes the first time the output signal of the position sensor 31 changed from LOW to HIGH, and the second time it changed from HIGH to LOW. The initial value of the signal change information is 0 for both the first and second counts. The signal change information is updated to its initial value each time the movement control is successfully completed.

[0071] (Management of tray information) Figure 15 is a flowchart of the processes that the CPU 1307 performs to manage tray information. In S10, the CPU 1307 determines whether it has been instructed by the controller 1302 to move tray 8 to the loading / unloading position, that is, to perform pull-out control. If the controller 1302 has not instructed the CPU 1307 to perform pull-out control, in S16 the CPU 1307 determines whether it has been instructed by the controller 1302 to move tray 8 to the storage position, that is, to perform retraction control. If the controller 1302 has not instructed the CPU 1307 to perform retraction control, the CPU 1307 repeats the process from S10.

[0072] In S10, if the controller 1302 instructs the CPU 1307 to execute the drawer control, in S11 the CPU 1307 sets the tray position information to "drawing" and starts the drawer control of tray 8. Subsequently, in S12 the CPU 1307 determines whether an abnormality in the drawer control has been detected. The CPU 1307 detects failures of components related to movement control, such as the drive source 20 and the position sensor 31, by any method, and if a failure of a component related to movement control is detected, it determines that an abnormality in the drawer control has been detected. For example, the CPU 1307 may also determine that an abnormality in the drawer control has been detected if it detects that the load on the drive source 20 has become greater than a predetermined value. The former can correspond to abnormalities due to internal factors, and the latter can correspond to movement due to external factors.

[0073] If no abnormality in the drawer control is detected, the CPU 1307 updates the signal change information in S13 based on the output signal of the position sensor 31. In S14, the CPU 1307 determines whether the tray 8 has moved to the attachment / detachment position based on the output signal of the position sensor 31. If the tray 8 has not moved to the attachment / detachment position, the CPU 1307 repeats the process from S12. On the other hand, if the tray 8 has moved to the attachment / detachment position, the CPU 1307 sets the tray position information to "attachment / detachment position" in S15, initializes the signal change information, and terminates the process shown in Figure 15.

[0074] If an abnormality in the draw-out control is detected in S12, the CPU 1307 sets the status information to "abnormal stop (external factor)" or "abnormal stop (internal factor)" in S22, stops the draw-out control, and terminates the process shown in Figure 15. The CPU 1307 also displays an abnormality in the movement control on the operation unit 1304. Whether the status information is set to "abnormal stop (external factor)" or "abnormal stop (internal factor)" depends on the manner in which the draw-out control abnormality was detected.

[0075] In S16, if the controller 1302 instructs the CPU 1307 to execute retraction control, in S17 the CPU 1307 updates the tray position information to "retracting" and starts retraction control of tray 8. Subsequently, in S18 the CPU 1307 determines whether an abnormality in retraction control has been detected. The method for detecting an abnormality in retraction control is the same as the method for detecting an abnormality in withdrawal control.

[0076] If no abnormality in the retraction control is detected, the CPU 1307 updates the signal change information in S19 based on the output signal of the position sensor 31. In S20, the CPU 1307 determines whether the tray 8 has moved to the storage position based on the output signal of the position sensor 31. If the tray 8 has not moved to the storage position, the CPU 1307 repeats the process from S18. On the other hand, if the tray 8 has moved to the storage position, the CPU 1307 sets the tray position information to "storage position" in S21, initializes the signal change information, and terminates the process in Figure 15. If an abnormality in the retraction control is detected in S18, the CPU 1307 updates the status information in S22, stops the retraction control, and terminates the process in Figure 15.

[0077] Therefore, when the withdrawal control is successfully completed, the tray position information will indicate the "attachment / detachment position," the status information will indicate "normal," and the first and second signal change counts will each indicate 0. Similarly, when the retraction control is successfully completed, the tray position information will indicate the "storage position," the status information will indicate "normal," and the first and second signal change counts will each indicate 0.

[0078] On the other hand, if the withdrawal control is stopped midway, the tray position information will indicate "withdrawing," the status information will indicate "abnormal stop (external factor)" or "abnormal stop (internal factor)," and the first and second counts of the signal change information will each indicate the count at the time of the stop. Similarly, if the retraction control is stopped midway, the tray position information will indicate "with retraction," the status information will indicate "abnormal stop (external factor)" or "abnormal stop (internal factor)," and the first and second counts of the signal change information will each indicate the count at the time of the stop.

[0079] If the power to the image forming apparatus is cut off (OFF) during the withdrawal or retraction control process, the tray position information will show "withdrawing" or "with retracting," and the status information will show "normal." Furthermore, the first and second signal change counts will indicate the count at the time of stoppage, respectively.

[0080] As described above, tray information is recorded for trays 8 (hereinafter referred to as "target trays") that are in a state where they can move between the storage position and the attachment / detachment position depending on the rotation state of the rotary 9. Therefore, if there are no target trays depending on the rotation state of the rotary 9, the tray information may be deleted.

[0081] Furthermore, instead of managing tray information only for the target tray, it is also possible to configure the system to manage individual tray information for each of the trays 8a to 8d. In this case, for example, the tray information for a tray 8 that is not the target tray may indicate "storage position" as tray position information and "normal" as status information. Also, the first and second counts of the signal change information may each be 0. Alternatively, the tray information for a tray 8 that is not the target tray may indicate, for example, "immovable" as tray position information and "normal" as status information. Also, the first and second counts of the signal change information may each be 0. The CPU 1307 can determine which tray 8 is the target tray based on the rotation phase (rotation state) of the rotary 9.

[0082] (Initial processing when the image forming apparatus is started up) Figure 16 is a flowchart of the processes executed by the CPU 1307 when the image forming apparatus is started up, that is, when the power to the image forming apparatus is turned ON. In the following explanation, the startup of the image forming apparatus will be simply referred to as "startup". The process in Figure 16 is executed when a target tray exists. The process in Figure 16 determines whether the current position of the target tray is the storage position or the loading / unloading position, and if it cannot be determined that the current position of the target tray is the storage position or the loading / unloading position, it moves the target tray to the storage position or the loading / unloading position.

[0083] In S30, the CPU 1307 reads the tray information of the target tray from the non-volatile memory 1308. In S31, the CPU 1307 determines whether the current position of the target tray is the storage position or the loading / unloading position based on the tray information of the target tray. Specifically, if the tray position information indicates "storage position" or "loading / unloading position" and the status information indicates "normal", the CPU 1307 determines that the position indicated by the tray position information is the current position of the target tray.

[0084] If the CPU 1307 determines that the current position of the target tray is the storage position or the loading / unloading position, it determines in S31 that position confirmation control is unnecessary and terminates the process shown in Figure 16. On the other hand, if it cannot determine that the current position of the target tray is the storage position or the loading / unloading position, the CPU 1307 determines in S31 that position confirmation control is necessary.

[0085] If the CPU 1307 determines that position confirmation control is necessary, it determines in S32 whether the tray position information is "pulling out" or "pulling in". If the tray position information is "pulling out" or "pulling in", the CPU 1307 executes the first position confirmation control in S33. If the tray position information is neither "pulling out" nor "pulling in", the CPU 1307 executes the second position confirmation control in S34. Specifically, if the tray position information indicates the "storage position" or "attachment / detachment position" but the status information does not indicate "normal", the CPU 1307 executes the second position confirmation control in S34. The first position confirmation control can also be described as the process of moving a target tray whose current position is an intermediate position to the storage position or attachment / detachment position and confirming its position. The second position confirmation control can also be described as the process of moving a target tray whose current position is unknown to the storage position or attachment / detachment position and confirming its position.

[0086] (First position determination control) First, let's explain the first position determination control. The non-volatile memory 1308 stores control content information as illustrated in Figure 17. The control content information is a combination of tray position information and state information, and indicates the movement control content to be performed on the target tray in the first position determination control.

[0087] If the image forming apparatus is stopped during withdrawal control, the direction of movement of the target tray at the time the image forming apparatus was stopped is the withdrawal direction. If the tray position information indicates "withdrawing" and the status information indicates "normal", the CPU 1307 determines that the withdrawal control has stopped due to the power being turned off or the like during withdrawal control. In this case, the CPU 1307 moves the target tray to the attachment / detachment position. In other words, the CPU 1307 executes withdrawal control. To put it another way, when the image forming apparatus is started, the CPU 1307 moves the target tray to the attachment / detachment position by moving it in the withdrawal direction, which is the direction of movement at the time the image forming apparatus was stopped. Furthermore, the CPU 1307 can determine the approximate number of output signal switchings until the target tray reaches the attachment / detachment position based on the signal change information. In other words, the CPU 1307 can determine the timing when the target tray reaches the attachment / detachment position based on the signal change information.

[0088] Even if the tray position information indicates "pulling out" and the status information indicates "abnormal stop (external factor)", the CPU 1307 moves the target tray to the loading / unloading position. In other words, the CPU 1307 performs the pulling-out control. To put it another way, when the image forming apparatus is started, the CPU 1307 moves the target tray to the loading / unloading position by moving it in the pulling direction, which is the direction of movement when the image forming apparatus was stopped. When the tray position information indicates "pulling out" and the status information indicates "abnormal stop (external factor)", it indicates that the pulling-out control before the power was turned off was stopped by an external factor. The fact that the power was turned off after the pulling-out control was stopped and then turned on again suggests that the user removed the external factor that interfered with the pulling-out control before turning on the power. Therefore, assuming that the external factor has been removed, the target tray is moved to the loading / unloading position.

[0089] If the tray position information indicates "pulling out" and the status information indicates "abnormal stop (internal factor)", the CPU 1307 first moves the target tray toward the storage position, and then moves it toward the attachment / detachment position. In other words, the CPU 1307 performs retraction control before performing pull-out control. Note that in the retraction control before performing pull-out control, it is not necessary to move the target tray to the storage position. Since the abnormal stop is due to an internal factor, repairs such as replacing the faulty part are necessary. Therefore, the power to the image forming apparatus is turned OFF for repairs, and the power to the image forming apparatus is turned ON after the repairs are completed. Because the failure occurred while moving toward the attachment / detachment position, the target tray is first moved in the opposite direction, that is, toward the storage position, to determine if the target tray can move normally, and then the target tray is moved toward the attachment / detachment position according to the control before the stop. If the target tray cannot move normally, the movement control is stopped without changing the tray information.

[0090] If the image forming apparatus is stopped during retraction control, the direction of movement of the target tray at the time the image forming apparatus was stopped is the retraction direction. If the tray position information indicates "retracting" and the status information indicates "normal", the CPU 1307 determines that the retraction control has stopped due to a power outage or other reason during retraction control. In this case, the CPU 1307 moves the target tray to the storage position. In other words, the CPU 1307 executes retraction control. To put it another way, when the image forming apparatus is started, the CPU 1307 moves the target tray to the attachment / detachment position by moving it in the retraction direction, which is the direction of movement when the image forming apparatus was stopped.

[0091] If the tray position information indicates "retracting" and the status information indicates "abnormal stop (external factor)", the CPU 1307 moves the target tray to the loading / unloading position. In other words, the CPU 1307 performs withdrawal control. To put it another way, when the image forming apparatus is started, the CPU 1307 moves the target tray to the loading / unloading position by moving it in the retraction direction, which is the direction of movement when the image forming apparatus is stopped. Stops due to external factors during retraction control mainly occur when a cartridge 7 of the wrong size is installed in the target tray, or when the cartridge 7 is not properly installed in the target tray. Therefore, in order to properly install the cartridge 7 in the target tray, the target tray is moved to the loading / unloading position.

[0092] If the tray position information indicates "retracting" and the status information indicates "abnormal stop (internal factor)", the CPU 1307 first moves the target tray toward the loading / unloading position, and then moves it toward the storage position. In other words, the CPU 1307 executes the withdrawal control before executing the retraction control. Note that it is not necessary to move the target tray to the loading / unloading position during the withdrawal control before executing the retraction control. Since the abnormal stop is due to an internal factor, repairs such as replacing the faulty part are necessary. Therefore, the power to the image forming apparatus is turned OFF for repairs, and the power to the image forming apparatus is turned ON after the repairs are completed. Since the failure occurred while moving toward the storage position, the target tray is first moved in the reverse direction, i.e., toward the loading / unloading position, to determine if the target tray can move normally, and then the target tray is moved toward the storage position according to the control before the stop. If the target tray cannot move normally, the movement control is stopped without changing the tray information.

[0093] (Second position determination control) Next, we will explain the second position determination control. As shown in the flowchart in Figure 15, when the tray position information is "storage position" or "attachment / detachment position", the status information should be "normal". However, due to some abnormality, for example, an abnormality in writing to the non-volatile memory 1308, a state may occur where the tray position information indicates "storage position" or "attachment / detachment position", but the status information indicates "abnormal stop (external factor)" or "abnormal stop (internal factor)". In such cases, even if the tray position information indicates "storage position", the target tray may be in an intermediate position or an attachment / detachment position. Therefore, it is not possible to determine the control content based on the content of the tray information, as in the first position determination control.

[0094] Therefore, the CPU 1307, for example, performs a tray pull-out control of the target tray regardless of the contents of the tray information and monitors the output signal. If the output signal changes, the CPU 1307 performs a tray pull-in control of the target tray and moves it to the storage position. Note that if the output signal changes during the initial pull-out control, it is not necessary to move the target tray to the attachment / detachment position. If the output signal does not change during the pull-out control, it is determined that the target tray is actually in the "attachment / detachment position". Therefore, if the output signal does not change during the pull-out control, the CPU 1307 performs a tray pull-in control of the target tray and monitors the change in the output signal. If the output signal changes during the pull-in control, the CPU 1307 moves the target tray to the storage position. Alternatively, the CPU 1307 moves the target tray to the attachment / detachment position, which is the position at startup. Note that if the output signal does not change during both the pull-out and pull-in controls, the CPU 1307 notifies of an abnormality in the movement control.

[0095] In the example above, the pull-out control was performed first, but the configuration could also be configured to perform the retraction control first. Alternatively, the configuration could be configured to perform the pull-out control first if the tray position information indicates the "storage position," and the retraction control first if the tray position information indicates the "attachment / detachment position." When the CPU 1307 moves the target tray to the storage position or attachment / detachment position, it updates the tray position information to match the destination of the target tray and updates the status information to "normal." If the tray position information or status information cannot be updated, the CPU 1307 notifies the user of an abnormality in the non-volatile memory 1308.

[0096] If the tray position information is unknown, the target tray may actually be stopped in an intermediate position. However, the control described above will ultimately move the target tray to either the storage position or the loading / unloading position. Therefore, by executing the initial processing shown in Figure 16 after startup, the position of the target tray after the initial processing will be determined to be either the "storage position" or the "loading / unloading position".

[0097] Furthermore, the system can be configured to manage only "normal" and "abnormal stop" as status information, without distinguishing between the cessation of movement control due to internal factors and the cessation of movement control due to external factors. In this case, for example, if the tray position information is "storage position" or "attachment / detachment position" and the status information is "normal", the system can be configured not to perform position determination control. Also, if the tray position information is "storage position" or "attachment / detachment position" and the status information is "abnormal stop", the system can be configured to perform the second position determination control described above. Also, if the tray position information is "pulling out" or "retracting in" and the status information is "normal", the system can be configured to move the target tray in the direction of movement indicated by the tray position information to set the target tray to the storage position or attachment / detachment position. Furthermore, if the tray position information is "pulling out" or "retracting in" and the status information is "abnormal stop", the system can be configured to control it in the same way as "abnormal stop (external factor)" or "abnormal stop (internal factor)" in Figure 17. If the operation follows the "abnormal stop (external factor)" scenario in Figure 17, the CPU 1307 moves the target tray to the loading / unloading position regardless of the direction of movement indicated by the tray position information. If the operation follows the "abnormal stop (internal factor)" scenario in Figure 17, the CPU 1307 moves the target tray in the opposite direction to the direction of movement indicated by the tray position information, and then moves the target tray in the direction of movement indicated by the tray position information, thereby moving the target tray to the loading / unloading position or storage position.

[0098] Furthermore, the system can be configured to manage only tray position information as tray information. In this case, if the tray position information is "storage position" or "attachment / detachment position," no position confirmation control is performed. If the tray position information is "pulling out" or "retracting in," the first or second position confirmation control described above is performed. When the first position confirmation control is performed, the control content may be determined according to whether the tray position information is "pulling out" or "retracting in." As an example, the control content when the first position confirmation control is performed can be the same as that shown in "normal" in Figure 17.

[0099] Furthermore, if only tray position information is managed as tray information, it is possible to configure the system to manage "in transit" without distinguishing between "pulling out" and "pulling in." In this case, if the tray position information is "storage position" or "attachment / detachment position," no position confirmation control is performed. If the tray position information is "in transit," for example, the tray is moved to one of the predetermined positions between the storage position and the attachment / detachment position.

[0100] Furthermore, the control content in position determination control performed when the tray position information is "pulling out," "pulling in," or "moving" is not limited to the examples described above, and may be other.

[0101] In this embodiment, the position sensor 31 outputs an output signal that alternately indicates a first state and a second state while the tray 8 is moving between the storage position and the attachment / detachment position, and outputs an output signal indicating the first state when the tray 8 is in the storage position or the attachment / detachment position. Furthermore, in this embodiment, the position sensor 31 outputs an output signal indicating either the first state or the second state when the tray 8 is stopped in an intermediate position. The first state is one of HIGH and LOW, and the second state is the other of HIGH and LOW.

[0102] Therefore, at startup, the CPU 1307 cannot determine from the output signal of the position sensor 31 whether the target tray is in the storage position, intermediate position, or loading / unloading position. Consequently, if the tray information described above is not managed, the CPU 1307 must perform control similar to the second position determination control described above if the target tray is present at startup, for example, to ensure that the target tray is always in the storage position. In other words, if the tray information described above is not managed, the CPU 1307 must always perform position determination control if the target tray is present at startup.

[0103] On the other hand, according to this embodiment, by managing tray information, the CPU 1307 only needs to perform position determination control when necessary, thus shortening the time until the image forming apparatus becomes usable. In this embodiment, position determination control is classified into first position determination control and second position determination control. First position determination control is performed when the target tray is in an intermediate position and is not performed when the position of the target tray is unknown, as in the case of second position determination control. Therefore, compared to the case where second position determination control is always performed, the time until the image forming apparatus becomes usable can be shortened.

[0104] In this embodiment, when the target tray is in the storage position or the attachment / detachment position, the output signal is LOW. However, when the target tray is stopped in an intermediate position, the output signal becomes HIGH or LOW. Therefore, for example, in the process shown in Figure 16, if the tray position information indicates the storage position or the attachment / detachment position, and the output signal is HIGH, it is possible to configure the system to determine that the target tray is in an intermediate position and perform the first position determination control. In this first position determination control, the target tray may be moved to a predetermined position among the attachment / detachment position and the storage position.

[0105] <Second Embodiment> Next, the second embodiment will be described, focusing on the differences from the first embodiment. For example, suppose that a command to replace cartridge 7 is input, and after the target tray is moved to the loading / unloading position, the power to the image forming apparatus is turned OFF. In this case, depending on the drive configuration of tray 8, it may be possible for the user to push the target tray towards the storage position by hand or the like while the power to the image forming apparatus is OFF. In such a case, the tray position information after startup is "loading / unloading position" and the status information is "normal", so the CPU 1307 will determine that the target tray is in a position different from its actual position when it is in the loading / unloading position.

[0106] Therefore, in this embodiment, the position sensor 31 is configured to show different output signals depending on whether the tray 8 is in the storage position or the attachment / detachment position. That is, when the tray 8 is in the storage position, the position sensor 31 outputs an output signal indicating the first state, and when the tray 8 is in the attachment / detachment position, the position sensor 31 outputs an output signal indicating the second state. In this embodiment as well, while the tray 8 is moving between the storage position and the attachment / detachment position, the position sensor 31 outputs an output signal that alternately switches between the first state and the second state. In the following description, when the target tray is in the storage position, the output signal indicates the first state (e.g., LOW), and when the target tray is in the attachment / detachment position, the output signal indicates the second state (e.g., HIGH).

[0107] (Initial startup process) The flowchart of the initial processing performed by the CPU 1307 at startup is basically the same as in Figure 16 of the first embodiment. However, in the first embodiment, the second position determination control was performed only when the tray position information indicated "storage position" or "attachment / detachment position" but the status information did not indicate "normal". In this embodiment, it is also performed when the tray position information indicates "storage position" but the output signal indicates the second state, that is, when it is determined based on the output signal that the target tray is not in the storage position. Furthermore, it is also performed when the tray position information indicates "attachment / detachment position" but the output signal indicates the first state, that is, when it is determined based on the output signal that the target tray is not in the attachment / detachment position. Note that if the position indicated by the tray position information and the position of the target tray determined based on the output signal do not match, the second position determination control is performed regardless of the content of the status information. Other cases are the same as in the first embodiment.

[0108] Although the first embodiment described a configuration in which state information is not managed, control can still be performed as in this embodiment even when state information is not managed. In other words, even if the tray position information is "storage position" or "attachment / detachment position," the system can be configured to perform a second position determination control according to the state indicated by the output signal.

[0109] Although each embodiment has been described using an image forming apparatus in which developing units 5a to 5d are mounted on a rotary 9 that is rotationally driven, each of the above embodiments can also be applied to an image forming apparatus that does not have a rotary 9. In other words, each of the above embodiments can be applied to an image forming apparatus that has a tray 8 that holds a cartridge 7 containing toner, and the tray 8 is configured to be movable within a range including a storage position and a loading / unloading position. Here, the storage position is a position in which the colorant of the cartridge 7 can be supplied to the developing unit 5, and the loading / unloading position may be a position in which the cartridge 7 held by the tray 8 can be replaced.

[0110] [Other embodiments] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0111] This embodiment includes the following configuration. (Composition 1) An image forming apparatus, A tray that holds the cartridge containing the toner, A moving means for moving the tray within a range including the first position and the second position, Control means for controlling the movement of the tray, and when the image forming apparatus is started, control means for determining whether or not to perform position determination control to set the position of the tray to the first position or the second position, based on tray information including tray position information relating to the position of the tray. An image forming apparatus equipped with the following features. (Configuration 2) Furthermore, it includes non-volatile memory devices, The image forming apparatus according to configuration 1, wherein the control means stores the tray information in the memory device. (Composition 3) Photoreceptor and A developing means for developing the electrostatic latent image formed on the photoreceptor, Furthermore, The first position is a position in which the toner contained in the cartridge held in the tray can be supplied to the developing means. The image forming apparatus according to configuration 1 or 2, wherein the second position is a position from which the cartridge held in the tray can be replaced. (Composition 4) The image forming apparatus according to configuration 3, wherein the developing means is provided inside a rotary that is driven to rotate. (Composition 5) The tray position information indicates that the tray is in the first position, the tray is in the second position, or the tray is between the first and second positions. The image forming apparatus according to any one of configurations 1 to 4, wherein the control means performs the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is between the first position and the second position. (Composition 6) If the tray position information indicates that the tray is between the first position and the second position, the tray position information further indicates the direction of movement of the tray. The image forming apparatus according to configuration 5, wherein the control means moves the tray to the first position or the second position by moving the tray in the direction of movement indicated by the tray position information when the image forming apparatus is started up, indicating that the tray is between the first position and the second position. (Composition 7) The image forming apparatus according to configuration 5, wherein if the tray position information when the image forming apparatus is started indicates that the tray is between the first position and the second position, the control means moves the tray to the first position or the second position by moving the tray in the direction of movement of the tray when the image forming apparatus is stopped. (Composition 8) The image forming apparatus according to any one of configurations 5 to 7, wherein the control means does not perform the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is in the first position or the second position. (Composition 9) The tray information further includes status information indicating whether or not the movement control has been stopped. If the tray position information indicates that the tray is between the first position and the second position, the tray position information further indicates the direction of movement of the tray. The image forming apparatus according to configuration 5, wherein the control means controls the movement of the tray in the position determination control based on the direction of movement of the tray indicated by the tray position information and the state information when the image forming apparatus is started up and the tray position information indicates that the tray is between the first position and the second position. (Composition 10) The image forming apparatus according to configuration 9, wherein the control means moves the tray to the first or second position by moving the tray in the direction of movement indicated by the tray position information when the image forming apparatus is started, if the tray position information indicates that the tray is between the first position and the second position and the state information does not indicate that the movement control has been stopped. (Composition 11) The image forming apparatus according to configuration 9 or 10, wherein the control means, when the image forming apparatus is started up, moves the tray to the second position regardless of the direction of movement indicated by the tray position information, or moves the tray to the first or second position by moving it in the direction of movement indicated by the tray position information, after moving it in the direction of movement indicated by the tray position information. (Composition 12) The image forming apparatus according to any one of configurations 9 to 11, wherein the control means indicates that the tray position information when the image forming apparatus is started is the first position or the second position, and executes the position determination control when the state information indicates that the movement control has been stopped. (Composition 13) The image forming apparatus according to any one of configurations 9 to 12, wherein the control means does not perform the position determination control if the state information does not indicate that the tray position information when the image forming apparatus is started is at the first position or the second position, and the movement control has been stopped. (Composition 14) The image forming apparatus according to any one of configurations 1 to 13, further comprising output means for alternately outputting output signals indicating a first state and a second state while the tray is moving between the first position and the second position. (Composition 15) The output means outputs an output signal indicating one of the first state and the second state when the tray is in the first position and when it is in the second position. The image forming apparatus according to configuration 14, wherein the control means determines, based on the output signal, whether the tray has moved to the first position and whether the tray has moved to the second position. (Composition 16) The image forming apparatus according to configuration 14 or 15, wherein the tray information includes information indicating the number of times the output means has changed the output signal after the start of the movement control. (Composition 17) The output means outputs the output signal indicating the first state when the tray is in the first position, and outputs the output signal indicating the second state when the tray is in the second position. The image forming apparatus according to any one of configurations 14 to 16, wherein the control means performs the position determination control when the tray position information indicates the first position but the output signal indicates the second state, and when the tray position information indicates the second position but the output signal indicates the first state. (Composition 18) The image forming apparatus according to configuration 17, wherein the control means, in the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is at the first position or the second position, controls the tray to move toward the first position or the second position, and if the output signal does not change, controls the tray to move in the opposite direction from before. (Composition 19) The output means includes a detected unit that moves in conjunction with the movement of the tray, and a sensor unit that outputs the output signal which changes according to the movement of the detected unit. The image forming apparatus according to any one of configurations 14 to 18, wherein the direction of movement of the detected part intersects with the direction of movement of the tray. (Composition 20) The image forming apparatus according to any one of configurations 1 to 19, wherein the control means, when movement control for moving the tray toward the second position is started, sets a value in the tray position information indicating that it is moving toward the second position; when the tray is moved to the second position, sets a value in the tray position information indicating that it is in the second position; when movement control for moving the tray toward the first position is started, sets a value in the tray position information indicating that it is moving toward the first position; and when the tray is moved to the first position, sets a value in the tray position information indicating that it is in the first position.

[0112] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0113] 8: Tray, 20: Drive unit, 31: Position sensor, 1307: CPU

Claims

1. An image forming apparatus, A tray that holds the cartridge containing the toner, A moving means for moving the tray within a range including the first position and the second position, Control means control the movement of the tray, and when the image forming apparatus is started, control means determine whether or not to perform position determination control to set the position of the tray to a first position or a second position based on tray information including tray position information relating to the position of the tray. An image forming apparatus equipped with the following features.

2. Further equipped with non-volatile memory devices, The image forming apparatus according to claim 1, wherein the control means stores the tray information in the memory device.

3. Photoreceptor and A developing means for developing the electrostatic latent image formed on the photoreceptor, Furthermore, The first position is a position in which the toner contained in the cartridge held in the tray can be supplied to the developing means. The image forming apparatus according to claim 1, wherein the second position is a position from which the cartridge held in the tray can be replaced.

4. The image forming apparatus according to claim 3, wherein the developing means is provided inside a rotary that is driven to rotate.

5. The tray position information indicates that the tray is in the first position, the tray is in the second position, or the tray is between the first and second positions. The image forming apparatus according to claim 1, wherein the control means performs the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is between the first position and the second position.

6. If the tray position information indicates that the tray is between the first position and the second position, the tray position information further indicates the direction of movement of the tray. The image forming apparatus according to claim 5, wherein the control means moves the tray to the first position or the second position by moving the tray in the direction of movement indicated by the tray position information when the image forming apparatus is started up, indicating that the tray is between the first position and the second position.

7. The image forming apparatus according to claim 5, wherein, when the image forming apparatus is started, the tray position information indicates that the tray is between the first position and the second position, the control means moves the tray to the first position or the second position by moving the tray in the direction of movement of the tray when the image forming apparatus is stopped.

8. The image forming apparatus according to claim 5, wherein the control means does not perform the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is in the first position or the second position.

9. The tray information further includes status information indicating whether or not the movement control has been stopped. If the tray position information indicates that the tray is between the first position and the second position, the tray position information further indicates the direction of movement of the tray. The image forming apparatus according to claim 5, wherein the control means controls the movement of the tray in the position determination control based on the direction of movement of the tray indicated by the tray position information and the state information when the image forming apparatus is started up and the tray position information indicates that the tray is between the first position and the second position.

10. The image forming apparatus according to claim 9, wherein the control means moves the tray to the first position or the second position by moving the tray in the direction of movement indicated by the tray position information when the image forming apparatus is started, if the tray position information indicates that the tray is between the first position and the second position and the state information does not indicate that the movement control has been stopped.

11. The image forming apparatus according to claim 9, wherein the control means, when the image forming apparatus is started up, indicates that the tray is between the first position and the second position, and the state information indicates that the movement control has been stopped, moves the tray to the second position regardless of the direction of movement indicated by the tray position information, or moves the tray in the opposite direction to the direction of movement indicated by the tray position information, and then moves the tray to the first position or the second position by moving the tray in the direction of movement indicated by the tray position information.

12. The image forming apparatus according to claim 9, wherein the control means indicates that the tray position information when the image forming apparatus is started is the first position or the second position, and if the status information indicates that the movement control has been stopped, the position determination control is executed.

13. The image forming apparatus according to claim 9, wherein the control means does not perform the position determination control if the state information does not indicate that the tray position information when the image forming apparatus is started is at the first position or the second position, and the movement control has been stopped.

14. The image forming apparatus according to any one of claims 1 to 13, further comprising output means for alternately outputting output signals indicating a first state and a second state while the tray is moving between a first position and a second position.

15. The output means outputs an output signal indicating one of the first state and the second state when the tray is in the first position and when it is in the second position. The image forming apparatus according to claim 14, wherein the control means determines, based on the output signal, whether the tray has moved to a first position and whether the tray has moved to a second position.

16. The image forming apparatus according to claim 14, wherein the tray information includes information indicating the number of times the output means has changed the output signal after the start of the movement control.

17. The output means outputs the output signal indicating the first state when the tray is in the first position, and outputs the output signal indicating the second state when the tray is in the second position. The image forming apparatus according to claim 14, wherein the control means performs the position determination control when the tray position information indicates the first position but the output signal indicates the second state, and when the tray position information indicates the second position but the output signal indicates the first state.

18. The image forming apparatus according to claim 17, wherein the control means, in the position determination control when the tray position information at the time the image forming apparatus is started indicates that the tray is at the first position or the second position, controls the tray to move toward the first position or the second position, and if the output signal does not change, controls the tray to move in the opposite direction from before.

19. The output means includes a detected unit that moves in conjunction with the movement of the tray, and a sensor unit that outputs the output signal which changes according to the movement of the detected unit. The image forming apparatus according to claim 14, wherein the direction of movement of the detected part intersects with the direction of movement of the tray.

20. The image forming apparatus according to any one of claims 1 to 13, wherein the control means, when movement control for moving the tray toward the second position is started, sets a value in the tray position information indicating that it is moving toward the second position; when the tray is moved to the second position, sets a value in the tray position information indicating that it is in the second position; when movement control for moving the tray toward the first position is started, sets a value in the tray position information indicating that it is moving toward the first position; and when the tray is moved to the first position, sets a value in the tray position information indicating that it is in the first position.

Images