JP2018039600A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device that can form an image without making a user wait when a predetermined sheet output part is not compatible with an output sheet.SOLUTION: An image formation device includes a plurality of output parts for outputting a sheet formed with an image, of which at least one is stretchable. The image formation device detects a stretch state of the stretchable output part and selects an output part compatible with a size of output sheet based on the stretch state.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus capable of detecting expansion and contraction of a tray for discharging a sheet.

  2. Description of the Related Art Conventionally, in some image forming apparatuses that discharge a sheet on which an image is formed to a tray, a discharge tray can be extended and contracted in order to reduce an installation area of the apparatus. In that case, when discharging a small sheet (for example, A4 size), it may be in a contracted state, but when discharging a large sheet (for example, A3 size), the discharge tray is extended so that the sheet does not fall off. . In general, in order to prevent the sheet from dropping, a sensor is provided in the paper discharge tray to monitor whether or not the paper discharge tray is extended. doing. And when not extended | stretched, it controls so that a large sheet | seat is not discharged.

JP 2006-213467 A

  However, in the prior art, when the size of the used sheet is longer than the contracted state of the discharge tray, a message prompting extension of the discharge tray is displayed, and printing is performed after the discharge tray is extended. It has been proposed to start the process. As a result, the sheet can be prevented from dropping, but the printing process is started only after the sheet discharge tray is extended, and as a result, the user is kept waiting.

  The present invention has been made in view of the problems existing in the prior art, and forms an image without waiting for a user when a scheduled sheet discharge unit does not correspond to a sheet to be discharged. It is an object of the present invention to provide an image forming apparatus capable of doing so.

  In order to achieve the above object, the present invention has the following configuration.

A plurality of discharge portions that can expand and contract at least one for discharging the image-formed sheet;
Detection means for detecting the expansion / contraction state of the extendable discharge section;
A selection unit that selects a discharge unit corresponding to the size of the discharged sheet based on the expansion / contraction state detected by the detection unit;
It is characterized by having.

  According to the present invention, it is possible to form an image without waiting for the user when the scheduled sheet discharge unit does not correspond to the sheet to be discharged.

1 is a cross-sectional view showing an internal configuration of an image forming apparatus according to the present invention. 1 is a block diagram showing an internal configuration of an image forming apparatus according to the present invention. It is sectional drawing of the paper discharge part which concerns on this invention. It is sectional drawing of the paper discharge part which concerns on this invention. It is a flowchart which shows a present Example. It is a size correspondence table of the discharge tray expansion / contraction detection sensor of the present embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[Embodiment 1]
In this embodiment, an electrophotographic copying machine will be described as an example of an image forming apparatus.

(Image forming device)
FIG. 1 is a schematic cross-sectional view showing the configuration of the image forming apparatus. In the image forming apparatus 100, the sheet feeding unit 10, the image forming unit 20, the fixing unit 30, and the sheet discharging unit 40 are sequentially arranged from the lower side (upstream in the sheet conveying direction) to the upper side (downstream in the sheet conveying direction) in FIG. Is provided. A sheet refeeding unit 50 is provided on the right side of the image forming unit 20 and the fixing unit 30.

  In the sheet feeding unit 10, the sheets P stacked on the feeding cassette 11 and the manual feed tray 16 are fed to the image forming unit 20. The sheet detection sensor S <b> 1 is a sensor that detects whether or not the sheet P is stored in the feeding cassette 11. The sheet P stored in the feeding cassette 11 is fed to the separation roller pair 13 as the pickup roller 12 rotates. When the sheet P is double-fed, it is separated into one sheet by a separating roller pair 13 composed of a normal rotation roller and a reverse roller, and is conveyed to a feeding path PS1 indicated by a solid line. The sheet P conveyed to the feeding path PS is further conveyed by the feeding roller pair 14, and the skew of the sheet P is corrected by the front end following the nip of the registration roller pair 15 that has stopped rotating. The pre-registration sensor S2 detects the timing at which the leading edge of the sheet P reaches the nip of the registration roller pair 15.

  When the sheet P is fed from the manual feed tray 16, the sheet is separated into one sheet by the supply roller 17 and the separation pad 18 and pulled into the apparatus. Then, the sheet is conveyed to the feeding roller pair 14 by the supply roller pair 19, and the skew of the sheet P is corrected by the registration roller pair 15. The sheet P whose skew has been corrected is conveyed to the image forming unit 20 by the registration roller pair 15 rotating at a predetermined timing.

  In the image forming unit 20, the surface of the photosensitive drum 21 is uniformly charged by the charging roller 22. Laser light corresponding to the image information is emitted from the laser unit 23. In the portion of the photosensitive drum 21 irradiated with the laser light, the charge charged by the charging roller 22 is removed, and an electrostatic latent image corresponding to the image information is formed. The electrostatic latent image formed here is visualized as a developer image when the developer is attached by the developing roller 24.

  The developer image is conveyed to the transfer nip portion N1 by the rotation of the photosensitive drum 21. In synchronization with this timing, the sheet P is conveyed from the registration roller pair 15 to the transfer nip portion N1. While the conveyed sheet P is nipped and conveyed by the transfer roller 25 in contact with the photosensitive drum 21 in the transfer nip portion N1, the developer image formed on the photosensitive drum 21 is transferred by the transfer roller 25. The laser light emitted from the laser unit 23 is controlled based on image data transmitted from the outside.

  Next, the sheet P on which the developer image is formed is conveyed to the fixing unit 30. In the fixing unit 30, a fixing roller 31 composed of an aluminum roller or the like heated to a predetermined fixing temperature by a heat source such as a halogen lamp disposed therein, and the fixing roller 31 in contact with the fixing roller 31 with a predetermined pressure. A fixing nip portion N2 is formed by the pressure roller 32 that presses the pressure. The sheet P on which the developer image is formed is sent to the fixing nip portion N2, and is nipped and conveyed between the fixing roller 31 and the pressure roller 32, and is heated and pressed, whereby the developer image is fixed on the sheet P. Is done. The fixing sensor S3 detects that the leading edge of the sheet P has passed through the fixing nip portion N2.

  The fixing unit 30 forms a fixing nip portion N2 by pressing the heat source such as a ceramic heater through the endless film, instead of the heating roller method in which the fixing roller 31 heats, An on-demand fixing method that heats and presses while the sheet P is nipped and conveyed at the nip portion N2 may be used.

  Next, the sheet P on which the developer image is fixed is conveyed to the sheet discharge unit 70 or 80 and discharged to the discharge tray T1 or T2 by the discharge roller pair. The paper discharge tray to be discharged can be selected, for example, by switching the path by a flap (not shown) provided at a branch point of the transport path.

  When forming images on both sides of the sheet P, the sheet P is conveyed to the sheet reversing unit 40. After the leading edge of the sheet P with the image formed on the first surface passes through the fixing sensor S3, the discharge roller pair 41 is temporarily stopped before the trailing edge of the sheet P passes through the discharge roller pair 41. By rotating in the reverse direction, the sheet P is reversed and conveyed to the sheet refeeding unit 50. The sheet P conveyed to the sheet re-feeding unit 50 is conveyed along a re-feed path PS2 indicated by a broken line by re-feed roller pairs 51 and 52, and is conveyed to a registration roller pair 15 by a re-feed roller pair 53. . Then, after the skew is corrected by the registration roller pair 15, the developer image is formed on the second surface of the sheet P by being conveyed to the transfer nip portion N1. Thereafter, the developer image is fixed on the sheet P by being conveyed through the fixing nip portion N2 in the same manner as when the image is formed on the first side, and the sheet P on which the image is formed on both sides is discharged by the discharge roller pair. The sheet 70 or 80 is discharged to the discharge tray T1 or T2.

  The tray sensor S11 is a sensor that is turned off when the paper discharge tray T1 is extended, and is turned on when it is contracted. The tray sensor S12 is a sensor that is turned off when the paper discharge tray T2 is extended, and is turned on when it is contracted. On and off may be reversed.

<Configuration of control unit>
FIG. 2 is a block diagram illustrating a configuration of the control unit 600 of the image forming apparatus 100. A CPU 601 included in the control unit 600 that controls the entire image forming apparatus includes a ROM 602 and a RAM 603. The ROM 602 is a read-only storage element in which various programs and data for image formation are written. A RAM 603 is a writable and erasable storage element, holds a program read from the ROM 602, and writes and erases processing data and calculation results generated during the sheet processing as needed. The EEPROM 604 is a storage area for storing device and user setting values.

  The CPU 601 converts image information input from an external PC or the like into irradiation information irradiated by the laser unit 23 by the image processing circuit 2. The CPU 601 drives the charging roller 22 via the image processing circuit 2 to uniformly charge the surface of the photosensitive drum 21 (FIG. 1).

  The CPU 601 drives the laser unit 23 in accordance with the irradiation information, and forms an electrostatic latent image corresponding to the image information by irradiating the photosensitive drum 21 (FIG. 1) with the laser beam, and develops by attaching the developer. Visualized as a drug image.

  In parallel with the image processing, when the sheet detection sensor S1 detects the sheet in the feeding cassette 11, the CPU 601 starts feeding the sheet P by driving the feeding motor 101 via the motor driver 1, before the registration. After the sheet is detected by the sensor S2, the sheet P is stopped at the position of the registration roller pair 16.

  The CPU 601 drives the feeding motor 101 again so that the sheet P reaches the transfer nip portion N1 at the timing when the developer image reaches the transfer nip portion N1 (FIG. 1), and transfers the developer image to the sheet P. Let

  The CPU 601 controls the temperature of the heater 33 built in the fixing roller 31 through the temperature control circuit 3 so as to reach the target temperature until the sheet P reaches the fixing unit 30 (FIG. 1). The temperature of the heater 33 is detected by the thermistor 34.

  When the leading edge of the sheet P passes through the fixing unit 30 (FIG. 1) and is detected by the fixing sensor S3, the CPU 601 drives the discharge motor 102 to rotate the discharge roller pair 41 (FIG. 1) to form an image. The discharged sheet P is discharged to the discharge tray 42 (FIG. 1).

  The CPU 601 can control the operation display unit 910 to display the state of the apparatus or accept an instruction from the user.

  Further, the CPU 601 can detect on / off of the tray sensors S11 and S12. Depending on whether the tray sensors S11 and S12 are on or off, it can be determined whether each of the trays T1 and T2 is in an expanded state or a contracted state.

<Configuration of sheet discharge unit>
3 and 4 are enlarged views of the sheet discharge units 70 and 80 of the image forming apparatus 100 according to the present exemplary embodiment. The paper discharge tray T1 and the paper discharge tray T2 are formed as two-stage extendable trays by sliding the movable portion with respect to the fixed portion in the direction along the paper transport direction. According to the printing paper size, the user can manually expand and contract along the paper transport direction. As shown in FIG. 3, when the paper discharge tray is contracted to only one level, the length of the paper discharge tray in the direction along the paper transport direction is minimum, and all the movable parts are stored in the fixed part. ing. At this time, the length of the paper discharge tray in the direction of paper conveyance is equal to the length of the fixing portion of the paper discharge tray T1 in the direction of paper conveyance and does not protrude from the side surface of the multifunction device 1. .

  On the other hand, as shown in FIG. 4, in the state where the paper discharge tray is extended, the length of the paper discharge tray in the direction along the paper transport direction is the maximum. The movable portion protrudes to the maximum, and the length in the direction along the paper conveyance direction is longer than the length of the maximum size (for example, A3 horizontal size) recording paper that can be printed by the multifunction device 1 in the paper conveyance direction. . Thus, when the paper discharge tray T1 or T2 is extended to the maximum length, even the maximum printable size recording paper can be stably stacked, and the discharged recording paper falls from the paper discharge tray. Disappears.

  A tray sensor S11 for detecting the expansion / contraction state of the discharge tray is installed in the discharge tray T1, and a tray sensor S12 is also installed in the discharge tray T2, and the ON / OFF change of each sensor by a photo interrupter or the like is installed. To detect the expansion / contraction state of the paper discharge tray. When the paper discharge tray is in the contracted state, the tray sensor is turned on. When the paper output tray is in the extended state, the tray sensor is turned off, so that the state of the paper discharge tray can be detected. .

  Further, for example, the tray sensor may detect and control the expansion / contraction state of the discharge tray in detail from the change in the voltage value by AD conversion of the sensor information. Also, for example, as a sensor for detecting the length of the tray, a plurality of sensors are arranged along the expansion / contraction direction, and the length of the discharge tray is set to the maximum interval according to the on / off state of each sensor. It can also be detected in multiple stages as an error.

<Discharge tray detection processing operation flow during printing>
FIG. 5 is a flowchart showing a flow in the present embodiment. FIG. 6 shows the stack size of the tray sensor in this embodiment. From the table of FIG. 6, when the requested paper size is a small size group such as A4, letter, and B5, it is assumed that the paper discharge tray may be in a contracted state or an extended state. If the requested paper size is a large size group such as A3, Legal, B4, etc., the paper discharge tray must be in an extended state. However, since a small size paper may be in either an expanded or contracted state, only the paper size that can be discharged is stored only when the tray expansion / contraction detection sensor is off (that is, in the extended state). It may be left. In this case, since only the paper size corresponding to the expanded state needs to be stored, it is not necessary to store the states in association with each other.

  The image forming apparatus 100 controls printing according to the control of the CPU 601. That is, the processing procedure in FIG. 5 is realized by the CPU 601 executing a program. As shown in FIG. 5, the CPU 601 determines the length (state) of the paper discharge tray from the requested paper size (S501). The requested paper size is, for example, a paper size set by the user via the operation display unit 910 or a paper size specified in a print job received from an external computer or the like. Alternatively, if the image forming apparatus 100 is an MFP in which the scanner unit and the image forming unit are integrated, the document size to be read detected by the scanner unit may be set to the requested paper size.

  Next, the processing branches depending on whether or not a paper discharge tray is specified in the job (S502). If the discharge destination paper discharge tray is an automatic selection instruction (YES in S502), the expansion / contraction state of all the paper discharge trays is detected. In this embodiment, the expansion / contraction state of the paper discharge tray T1 and the paper discharge tray T2 is detected by the state of the tray sensors S11 and S12 (S503). From the detection result, the state of the paper discharge tray, that is, the length is calculated (S504). In this embodiment, as shown in FIG. 6, the recommended paper size is categorized according to the state of the paper discharge tray expansion / contraction detection sensor, so that the requested paper size can be stacked from the calculation result. It is determined whether there is a proper paper discharge tray (S505). However, in this embodiment, it can be considered that the state of the tray sensor indicates the length of the paper discharge tray as it is, and therefore it is not necessary to calculate the length in step S504. In that case, for example, a paper list of paper sizes that require the paper discharge tray to be in an extended state is stored in the ROM 602. If the size corresponding to the requested paper size is included in the stored paper list, if there is an extended tray in the paper discharge tray, it is determined in S505 that the corresponding tray is present. . On the other hand, if the requested paper size is not included in the paper list, it is determined that there is a corresponding tray regardless of the expansion / contraction state of the discharge tray. However, in the case where a stack sensor that detects that sheets are already stacked on the discharge tray is provided, it is desirable to exclude the tray on which sheets are already stacked from the discharge tray to be used.

  If it is determined that there is a paper discharge tray on which the requested paper size can be stacked (YES in S505), the paper discharge tray to be used is determined as a paper discharge tray on which the paper size can be stacked (S507). In the present embodiment, when there are a plurality of corresponding trays, control is performed so as to select a tray at which the printing process is completed at the fastest speed. Therefore, the discharge tray T1 is the highest priority tray. Therefore, for example, if both trays are the corresponding trays, the paper discharge tray T1 is determined as the paper tray of the paper discharge destination. When there are three or more paper discharge trays, priority may be given to each paper discharge tray, and according to the priority order, it may be determined whether or not each paper discharge tray satisfies a condition as a discharge destination. Further, when the requested paper size is a small size, that is, for example, a size that is not included in the paper list, the extended paper discharge tray can be used. It is desirable to preferentially select a paper discharge tray to be used as a paper discharge tray. For example, if the output tray is equipped with a stack sensor, and the tray on which the paper is stacked is not used, the extended output tray required for discharging large-size paper should be preserved as much as possible. This is because it is desirable. The automatic selection of the paper discharge tray can be changed according to the mode, paper type, and the like.

  On the other hand, if both of the paper discharge trays T1 and T2 are in a stretchable state in which the requested paper size cannot be stacked (NO in S505), the paper discharge tray T1 or T2 is stretched or contracted according to the paper size. A message, a symbol, or the like indicating that it is desired is displayed on the operation display unit 910 or the like, and the operator is notified (S506). This prompts the user to change the expansion / contraction state of the paper discharge tray to a state suitable for the paper size.

  In the case where the discharge destination discharge tray is not the automatic selection instruction but the discharge destination designation is set (NO in S502), for example, a specific discharge tray such as the discharge tray T1 is set by the print job or the operation display unit 910. Assuming that it has been selected, the following will be described. The expansion / contraction state of the selected discharge tray T1 is detected based on the value indicated by the tray sensor S11 (S513), and the state / length of the selected discharge tray T1 is calculated (S514). This can be skipped as in step S504. From the calculation result, it is determined whether the requested paper size can be stacked on the paper discharge tray T1 (S515). If it is determined that stacking is possible (YES in S515), the paper discharge tray T1 is determined and the printing process is started (S520).

  However, if it is determined that the expansion / contraction state of the discharge tray T1 does not correspond to the specified paper size, for example, it is shorter than the paper size (NO in S515), it is determined whether discharge to another discharge tray is possible. Therefore, for example, the expansion / contraction state of the discharge tray T2 is detected by the tray sensor S12 (S516), and the state and / or length of the discharge tray T2 is calculated (S517). This can be skipped as in step S504. From this calculation result, it is determined whether the requested paper size can be stacked on the paper discharge tray T2 (S518). If it is determined that stacking is possible (YES in S518), the paper discharge tray to be used is determined as the paper discharge tray T2, and printing processing is started (S520).

  If the paper discharge tray T2 is in a stretchable state in which the requested paper size cannot be stacked (NO in S518), the display unit 910 is requested to expand or contract the paper discharge tray T1 or T2 according to the paper size. Is displayed (S519).

  Image formation is started with the paper discharge unit (discharge tray) selected in this way as a discharge destination, and the paper on which the image has been formed is discharged to the paper discharge unit selected as the discharge destination.

  In this embodiment, there is only one tray sensor provided for each paper discharge tray, and only two states, an extended state and a contracted state, can be detected. However, a plurality of sensors are provided to detect the tray length in multiple stages. Then, a tray that is just right for the paper size may be selected.

  Further, in this embodiment, the two discharge trays are implemented as extendable trays, but three or more trays are installed, or one is extendable and one is not stretchable. A fixed tray may be used, and paper that cannot be discharged to the fixed tray may be discharged to a retractable discharge tray. As described above, according to the image forming apparatus of the embodiment, when at least one of a plurality of discharge trays that can expand and contract is present, the expansion and contraction state of the extendable discharge tray is detected, and By automatically switching to a paper discharge tray having a length that satisfies the stackability with respect to the length, the stackability can be improved without waiting for the user.

[Other Embodiments]
In the above-described embodiment, it has been described that the discharge tray can be stacked as long as it is a small size sheet even in a contracted state. However, for example, in the case where the paper discharge tray is a storage type and is folded or slid and stored in the image forming apparatus main body, it cannot be discharged onto the tray in the stored state. In such a case, even if the requested paper size is the smaller one, the paper discharge tray needs to be extended to the extent that at least the small size can be placed. Therefore, in this case, it is determined in, for example, steps S505, S515, and S518 whether the paper discharge tray is in a state corresponding to the paper size regardless of the requested paper size. Further, in this case, it is desirable to store the paper list in association with the paper size and the detection value of the tray sensor indicating the state of the paper discharge tray corresponding to the paper size as shown in FIG.

  10 sheet feeding unit, 11 feeding cassette, 70/80 paper ejection unit, T1 paper ejection tray, T2 paper ejection tray, S11 tray sensor, S12 tray sensor, 800 engine control unit, 900 controller, 910 display unit

Claims (6)

A plurality of discharge portions that can expand and contract at least one for discharging the image-formed sheet;
Detection means for detecting the expansion / contraction state of the extendable discharge section;
A selection unit that selects a discharge unit corresponding to the size of the discharged sheet based on the expansion / contraction state detected by the detection unit;
An image forming apparatus comprising:   The image according to claim 1, wherein the selection unit selects the discharge unit based on a relationship between a length of the discharge unit detected by the detection unit and a size of a discharged sheet. Forming equipment.   When the discharge unit is designated and the length of the designated discharge unit does not correspond to the size of the sheet to be discharged, the selecting means discharges from the discharge unit other than the specified one. The image forming apparatus according to claim 2, wherein a discharge unit corresponding to a size of the sheet to be selected is selected.   4. The apparatus according to claim 1, wherein the selection unit selects the discharge unit according to a predetermined priority when there are a plurality of discharge units corresponding to the size of the discharged sheet. 5. The image forming apparatus described.   In the case where there is no discharge unit corresponding to the size of the discharged sheet, there is a notification means for notifying the operator to change the expansion / contraction state of the extendable discharge unit to the expansion / contraction state corresponding to the size of the discharged sheet The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A control method for an image forming apparatus having a plurality of discharge portions, at least one of which discharges an image formed sheet, which can be expanded and contracted
A detection process for detecting the expansion / contraction state of the extendable discharge section;
A selection step of selecting a discharge portion corresponding to the size of the discharged sheet based on the expansion / contraction state detected in the detection step;
A control method for an image forming apparatus, comprising:

Images