JP4566897B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus such as a copying machine or a printer that records an image on a recording material such as paper in an image recording unit.

  The image recording apparatus transports the recording material fed from the paper feeding unit along the transport direction, and records an image on the recording material by the image recording unit. In the image recording unit, it is necessary to record an image at an appropriate position of the recording material. The image recording position on the recording material in the transport direction is determined by the transport timing of the recording material with respect to the image recording unit.

  The conventional image recording apparatus includes a registration roller on the upstream side of the image recording unit in the recording material conveyance direction. The registration roller rotates intermittently while the recording material is conveyed from the paper feeding unit to the image recording unit. The recording material fed from the paper feeding unit comes into contact with the non-rotating registration roller and temporarily stops moving to the image recording unit. Thereafter, the registration roller starts rotating at a timing corresponding to the image recording operation in the image recording unit. The recording material resumes moving to the image recording unit at the timing when the leading end of the image recording position faces the image recording unit at the start of the image recording operation.

  The inclination of the recording material in the surface of the recording material is corrected by contact with the non-rotating registration roller. As a result, it is possible to prevent the image from being inclined and recorded on the recording material.

  However, the positions of the paper feeding unit and the image recording unit in the direction orthogonal to the transport direction do not necessarily match. In addition, when the recording material is fed from the paper feeding unit or while the recording material is conveyed from the paper feeding unit to the image recording unit, the position of the recording material in a direction orthogonal to the conveyance direction may change. If this is left unattended, an image cannot be recorded at an appropriate position in the direction orthogonal to the conveying direction on the recording material.

Therefore, some conventional image recording apparatuses detect the position of the recording material in the direction orthogonal to the transport direction, and move the image recording position in the image recording unit based on the detection result (for example, (See Patent Documents 1 and 2.) With this configuration, the relative positions of the recording material and the image in the transport direction can be matched.
Japanese Patent Laid-Open No. 08-095432 Japanese Patent Laid-Open No. 10-181127

  However, in order to move the image recording position in the image recording unit, complicated control such as adjustment of the output timing of image data is required. For example, in an electrophotographic image recording apparatus that exposes a photosensitive member with laser light deflected by a polygon mirror, from when the laser light is received at a predetermined position outside the image area until image data is output to the semiconductor laser. Time must be adjusted.

  In recent years, there has been a significant demand for speeding up image recording apparatuses. For this reason, it is difficult to complete the processing necessary for adjusting the output timing of the image data between the detection of the position of the recording material and the start of image recording.

  The object of the present invention is to displace the position of the recording material in the main scanning direction orthogonal to the conveying direction on the upstream side of the image recording unit in the conveying direction, thereby simplifying the relative position between the recording material and the image in the main scanning direction. An object of the present invention is to provide an image recording apparatus that can be matched by processing.

As means for solving the above problems,
The image recording apparatus of the present invention includes a conveying member, an image recording unit, a detection member, and a displacement mechanism. The conveying member conveys the recording material along a predetermined conveying direction. The image recording unit records an image on a recording material. The detection member detects the position of the recording material in the main scanning direction orthogonal to the conveyance direction on the upstream side of the image recording unit in the conveyance direction. The displacement mechanism displaces the recording material in the main scanning direction according to an error in the position of the recording material with respect to a reference position determined based on the image recording position of the image recording unit in the main scanning direction. The image recording apparatus further includes an error storage unit and a control unit. The error storage unit stores a history of errors in the position of the recording material with respect to the reference position. The control unit corrects the image recording position and the reference position based on the stored contents of the error storage unit.

In this configuration, an error in the position of the recording material with respect to a predetermined reference position is calculated in the main scanning direction. In accordance with this error, the recording material conveyed to the image recording unit is displaced in the main scanning direction. The reference position is determined based on the image recording position in the main scanning direction. Therefore, the recording material is transported to a position suitable for the image recording position. Further, the image recording position of the image recording unit and the corresponding reference position are changed according to the history of errors from the reference position of the positions of the plurality of recording materials in the direction orthogonal to the transport direction. When a plurality of recording materials continuously cause the same error from the reference position, image recording is performed based on the position of the recording material, and the movement of the recording material by the displacement mechanism is not repeated.

  In the above image recording apparatus, a registration roller can be used as the recording material conveying member. The registration roller temporarily stops the recording material at a position close to the image recording unit on the upstream side of the image recording unit in the conveyance direction, and then the image of the recording material at a timing according to the image recording operation of the image recording unit. The conveyance to the recording unit is started.

  Therefore, immediately before the recording material in the main scanning direction is conveyed to the image recording unit, the position in the main scanning direction is corrected to a position corresponding to the image recording position with the inclination corrected.

  In the image recording apparatus described above, the displacement mechanism moves the registration roller forward so that the difference between the detection result of the detection member and the reference position is eliminated after the registration roller starts conveying the recording material to the image recording unit. Let Thereafter, the displacement mechanism moves the registration roller backward after the recording material passes through the registration roller and before the next recording material reaches the registration roller.

  Therefore, the recording material is not displaced while the image is recorded. Further, the next recording material does not contact the moving registration roller.

  According to the present invention, when the position of the recording material in the main scanning direction has an error from the reference position, the recording material can be moved to the reference position according to the error before the recording material reaches the image recording unit. it can. As a result, the recording material is conveyed to the image recording unit in a state where the position in the main scanning direction matches the image recording position. In the image recording unit, the relative positions of the image and the recording material in the main scanning direction coincide with each other, and the image is recorded at an appropriate position of the recording material.

  Therefore, the difference between the detection result of the position of the recording material and the reference position is an amount by which the recording material should be displaced, and the displacement mechanism may be operated according to this amount. For this reason, the relative position of the image recording position and the recording material in the main scanning direction can be matched by a simple process.

  An image recording apparatus according to the best embodiment of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic front sectional view showing the configuration of an image recording apparatus according to an embodiment of the present invention. The image recording apparatus 100 of the present invention includes an image reading unit 200, an image recording unit 300, and a paper feed unit 400.

  The image reading unit 200 includes an automatic document feeder (ADF) 201, a first document table 202, a second document table 203, a first mirror base 24, a second mirror base 205, a lens 206, and a solid-state image sensor ( A CCD (Charge Coupled Device) 207 is provided.

  The ADF 201 conveys documents one by one from the document tray 211 to the discharge tray 212 via the second document table 203. The ADF 201 is rotatable about the back side so that the top surface of the first document table 202 can be opened and closed. The ADF 201 is rotated so that the front side moves upward to expose the upper surface of the first document table 202, and then the document is placed on the first document table 202 by manual operation.

  Both the first platen 202 and the second platen 203 are made of hard glass plates.

  The first mirror base 204 and the second mirror base 205 are disposed below the first document table 202 and the second document table 203 so as to be movable in the horizontal direction. The second mirror base 205 moves at half the moving speed of the first mirror base 204. The first mirror base 204 is equipped with a light source and a first mirror. The second mirror base 205 is equipped with a second mirror and a third mirror.

  When reading an image of a document conveyed by the ADF 201, the first mirror base 204 is stopped below the second document table 203. The light from the light source is emitted toward the image surface of the document passing over the second document table 203, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  When reading an image of a document placed on the first document table 202, the first mirror base 204 and the second mirror base 205 move horizontally below the first document table 202. The light from the light source is emitted toward the image surface of the document placed on the first document table 202, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  Regardless of whether or not the ADF 201 is used, the reflected light on the image surface of the document is incident on the CCD 207 via the lens 206 by the second mirror and the third mirror with a constant optical path length.

  The CCD 207 outputs an electrical signal corresponding to the amount of reflected light on the image surface of the document. This electrical signal is input to the image forming unit 300 as image data.

  The image recording unit 300 includes a photosensitive drum 31, a charger 32, an exposure device 33, a developing device 34, a transfer belt 35, a cleaner 36, and a fixing device 37 that constitute the image recording unit 30. The image recording unit 300 records an image on a sheet as a recording material of the present invention by an electrophotographic image recording process.

  The photosensitive drum 31 has a photosensitive layer formed on the surface thereof, and rotates in the direction of the arrow. The charger 32 uniformly charges the surface of the photosensitive drum 31 to a predetermined potential. The charger 32 may use either a non-contact type discharge wire, or a contact type roller or brush.

  The exposure device 33 irradiates the surface of the photosensitive drum 31 with light based on the image data. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31 by the photoconductive action in the photosensitive layer. The exposure device 33 is a laser scanning unit, and scans laser light modulated based on image data in the axial direction of the photosensitive drum 31 via a polygon mirror. Alternatively, an exposure apparatus in which light emitting elements such as EL and LEDs are arranged in an array can be used.

  The developing device 34 supplies toner to the surface of the photosensitive drum 31 and visualizes the electrostatic latent image into a toner image.

The transfer belt 35 is looped between a plurality of rollers below the photosensitive drum 31, and has a resistance value of about 1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm. Inside the loop-shaped movement path of the transfer belt 35, there is provided a transfer roller 35A that presses against the photosensitive drum 31 with the transfer belt interposed therebetween. A predetermined transfer voltage is applied to the transfer roller 35 </ b> A, and a toner image carried by the photosensitive drum 31 is transferred onto a sheet passing between the transfer belt 35 and the photosensitive drum 31.

  The cleaner 36 removes residual toner from the surface of the photosensitive drum 31 after the transfer of the toner image to the paper.

  The fixing device 37 includes a heating roller 37A and a pressure roller 37B. The heating roller 37A is heated by an internal heater to a temperature at which the toner can be melted. The pressure roller 37B is in pressure contact with the heating roller 37A with a predetermined pressure. The fixing device 37 firmly fixes the toner image onto the paper by heating and pressurizing the paper passing between the heating roller 37A and the pressure roller 37B. The paper that has passed through the fixing device 37 is discharged to a paper discharge tray 38 mounted on one side surface of the image forming apparatus 100.

  The paper feed unit 400 includes paper feed cassettes 401 to 404 and a manual feed tray 405. Each of the paper feed cassettes 401 to 404 stores a plurality of sheets of the same size. On the manual feed tray 405, paper of a size or quality that is not frequently used is placed.

  Paper feed rollers 411 to 415 are arranged in the paper feed cassettes 401 to 404 and the manual feed tray 405. The paper feed rollers 411 to 415 feed the paper in the paper feed cassettes 401 to 404 and the manual feed tray 405 one by one to the transport path 11. The paper feed rollers 411 to 415 feed out the paper prior to the image recording operation in the image recording unit 30. The sheet is conveyed in the conveyance path 11 toward the image recording unit 30.

  A registration roller 40 is disposed on the transport path 11 on the upstream side of the image forming unit 30 in the transport direction. The registration roller 40 is close to the image recording unit 30 and rotates intermittently. When the leading edge of the sheet transported in the transport path 11 reaches the registration roller 40, the registration roller 40 stops rotating. The sheet is stopped by bringing the leading end into contact with the registration roller 40. This contact corrects the inclination of the paper. The registration roller 40 starts rotating at a predetermined timing. The sheet is placed in the image recording unit 30 so that the photosensitive drum 31 and the transfer roller 35A face each other, and the image recording start position on the sheet coincides with the front end of the toner image carried on the photosensitive drum 31. Be transported.

  FIG. 2 is a diagram illustrating a configuration in the vicinity of the registration roller 40 provided in the image recording apparatus 100. A drive roller 41, a driven roller 42, a support member 43, a sensor 44, a rack gear 45, a pinion gear 46, motors 48 and 48, and a clutch 49 are located upstream of the image forming unit 30 in the transport direction in the transport path 11. Has been placed.

  The driving roller 41 and the driven roller 42 constitute a registration roller 40 that is a conveying member of the present invention. The support member 43 pivotally supports the driving roller 41 and the driven roller 42. The support member 43 holds a motor 48 and a clutch 49. The rotation of the motor 48 is selectively supplied to the drive roller 41 via the clutch 49.

  Note that the conveyance member of the present invention does not necessarily need to be the registration roller 40, and other conveyance rollers or the like are used on the condition that the conveyance member is disposed on the upstream side of the image recording unit 30 in the sheet conveyance direction. Can do.

  The support member 43 is held in the image recording apparatus 100 so as to be capable of reciprocating in the direction indicated by the arrow X. An arrow X indicates a main scanning direction which is a direction orthogonal to the paper transport direction. A rack gear 45 is attached to the support member 43. The rack gear 45 meshes with a pinion gear 46 fixed to the rotating shaft of the motor 47. The rack gear 45, the pinion gear 46 and the motor 47 constitute the displacement mechanism of the present invention.

  The rotation of the motor 47 is converted into a linear motion in the main scanning direction by the rack gear 45 and the pinion gear 46 and transmitted to the support member 43. Therefore, the support member 43 moves in the main scanning direction by a length corresponding to the rotation time of the motor 47.

  The sensor 44 is a detection member of the present invention. The sensor 44 is disposed on the upstream side of the support member 43 in the transport direction and at a position close to the support member 43. The sensor 44 is, for example, a linear contact image sensor (CIS), and includes a plurality of light receiving elements along the main scanning direction. The plurality of light receiving elements of the sensor 44 are located in a range in which one side parallel to the paper transport direction passes in the main scanning direction.

  Each light receiving element receives reflected light when facing the paper. The sensor 44 outputs a detection signal corresponding to the light reception state of the reflected light from each light receiving element. Therefore, the detection signals for all the light receiving elements include an on-state signal from the time when the leading edge of the paper reaches the sensor 44 until the trailing edge of the paper passes over the sensor 44. The number of light receiving elements that receive the reflected light among all the light receiving elements varies depending on the position through which one side parallel to the paper transport direction passes. The number of signals in the on state among the detection signals for all the light receiving elements indicates the detection width of the paper (the length of the area where the paper is facing on the sensor 44).

  FIG. 3 is a block diagram illustrating a partial configuration of the control unit of the image recording apparatus 100. The controller 51 is connected to the exposure device 33, sensor 44, motor drivers 53 and 54, clutch driver 55, paper feed units 412 </ b> A to 414 </ b> A, and a storage unit 52.

  The control unit 51 outputs drive data to the motor drivers 53 and 54 and the clutch driver 55. A motor 47 and a motor 48 are connected to the motor drivers 53 and 54, respectively. A clutch 49 is connected to the clutch driver 55.

The motor driver 54 drives the motor 48 based on the drive data output from the control unit 51. The clutch driver 55 drives the clutch 49 based on the drive data output from the control unit 51. The drive roller 41 rotates while the motor 48 is driven and when the clutch 49 is driven. When the motor 48 is driven but the clutch 49 is not driven, the drive roller 41 does not rotate.

The motor driver 53 drives the motor 47 in the forward direction or the reverse direction based on the drive data output from the control unit 51. When the motor 47 is driven, the pinion gear 46 rotates, and the support member 43 moves in the main scanning direction together with the rack gear 45.

  The control unit 51 outputs image data to the exposure device 33. The exposure device 33 irradiates the photosensitive drum 31 with laser light modulated based on the image data. The exposure device 33 outputs a scanning position signal to the control unit 51. The scanning position signal is output from a BD (Beem Detect) sensor (not shown) disposed in the exposure apparatus 33.

  The BD sensor receives a scanning position signal when receiving laser light irradiated outside the image area on the photosensitive drum 31 out of the laser light deflected in the main scanning direction parallel to the axial direction of the photosensitive drum 31 by the polygon mirror. Is output. The controller 51 outputs image data for one line in the main scanning direction to the exposure device 33 when a predetermined writing start time has elapsed since the scanning position signal was input. The image recording position in the main scanning direction is determined by the writing start time.

  The controller 51 selectively outputs drive data to the paper feeding units 412A to 414A. The paper feed units 412A to 414A are provided in the paper feed cassettes 402 to 404, respectively. The paper feed units 412 </ b> A to 414 </ b> A rotate the paper feed rollers 412 to 414 based on the drive data output from the control unit 51 and feed the paper from the paper feed cassettes 402 to 404 to the transport path 11. The paper feed units 412A to 414A output a paper feed signal indicating that the paper has been fed out to the control unit 51.

  The storage unit 52 includes an error storage area 52A and a correction value storage area 52B. The error storage area 52A is an error storage unit of the present invention, and stores the error of the transport position of the paper fed from each of the paper feed cassettes 402 to 404 by a predetermined number of sheets retroactively from the latest one. The error in the paper transport position is the difference between the transport position based on the detection signal of the sensor 44 and a preset reference position, and is calculated by the control unit 51. The control unit 51 compares the detection width indicated by the detection signal output from the sensor 44 with the reference detection width of the sensor 44 when the sheet passes the reference position.

  The reference position is a position determined based on the image recording position of the image recording unit 30 and is set in each of the paper feed cassettes 402 to 404. When the paper transport position matches the reference position, the image recording unit 30 records an image at an appropriate position on the paper.

  The correction value storage area 52B stores a correction value for the writing start time for each paper feed position. In the image recording apparatus 100, there may be a fixed difference in the relative position between the photosensitive drum 31 and each of the paper feed cassettes 402 to 404 in the main scanning direction. A test image recording process is performed when the image recording apparatus 100 is shipped from the factory or when parts are replaced. A fixed difference is measured from the position of the image recorded on the paper in this experimental image recording process. By correcting the reference position and the writing start time with a correction value corresponding to this fixed difference, the sheet fed from any of the sheet feeding cassettes 402 to 404 is brought to an appropriate position in the main scanning direction. An image is recorded.

  Note that the storage contents of the error storage area 52A and the correction value storage area 52B can include information on the manual feed tray 405 as well as the paper feed cassettes 402 to 404.

FIG. 4 is a flowchart showing a processing procedure of the control unit 51. The control unit 51 selects, from among the paper feed cassettes 402 to 404, a paper feed cassette that stores paper of a size set as an image recording condition as a paper feed position (S1). The control unit 51 can also calculate the paper size from the document size and the recording magnification, and can select a paper feed cassette that stores paper of the calculated size as the paper feed position.

  The control unit 51 waits for an operation of a start key arranged on an operation panel (not shown) (S2). When the start key is operated, the control unit 51 outputs drive data to the paper feeding unit provided in the selected paper feeding cassette, and starts paper feeding (S3).

  The control unit 51 reads the detection signal of the sensor 44 at a predetermined timing after the start of paper feeding, detects the paper transport position in the main scanning direction (S4), and compares the detected transport position with the reference position (S5). . As described above, the control unit 51 uses the detection width indicated by the detection signals for all the light receiving elements as the transport position, and calculates the difference between this detection width and the reference detection width when the paper passes the reference position. The timing for reading the detection signal of the sensor 44 is after the leading edge of the fed paper comes into contact with the registration roller 40.

  When the transport position matches the reference position, the control unit 51 stores “0” in place of the oldest error information stored in the error storage area 52A (S6 → S9). When the transport position does not match the reference position, the control unit 51 calculates the difference between the transport position and the reference position (S6, S7). The control unit 51 performs an error correction process using the calculated difference (S8), and stores the difference value calculated this time in place of the oldest information in the error storage area 52A (S9).

  FIG. 5 is a flowchart showing the paper displacement process of the control unit 51. FIG. 6 is a timing chart showing the driving states of the motors 47 and 48 and the clutch 49 during the paper displacement process together with the state of the detection signal of the sensor 44. FIG. 7 is a diagram illustrating a displacement state of the sheet by the sheet displacement process. In the paper displacement process (S8), the control unit 51 calculates the drive time T of the motor 47 corresponding to the difference value calculated in S7 (S11). The control unit 51 compares the drive time T with the reference time TS (S12), and when the drive time T is equal to or greater than the reference time TS, stops the image recording operation and the sheet transport operation (S13).

  The detection signal of the sensor 44 does not include an on-state signal until the leading edge of the paper reaches the sensor 44. The on state is included in the detection signal of the sensor 44 between the time when the leading edge of the paper reaches the sensor 44 and the time when the trailing edge of the paper passes the sensor 44. The control unit 51 reads the detection signals for all the light receiving elements of the sensor 44 at least once between the time when the detection signal includes the on state and the time when the driving of the motor 47 should be started. The conveyance position is detected from the indicated detection width.

  The waveform of the detection signal of the sensor 44 in FIG. 6 indicates the logical sum of the detection signals for all the light receiving elements. This waveform is turned on from the time when the leading edge of the paper reaches the sensor 44 to the time when the trailing edge of the paper passes the sensor 44. From this waveform, it is possible to determine whether or not the paper is being conveyed.

  The reference time TS is a time obtained by dividing the interval between the trailing edge of the previously fed sheet and the leading edge of the next fed sheet by the conveyance speed. When the support member 43 is moved to correct the error, it is necessary to return the support member 43 to the original position before the leading edge of the next sheet reaches the registration roller 40. When the driving time T is equal to or longer than the reference time TS, the registration roller 40 is moved together with the support member 43 before the leading edge of the next sheet reaches the registration roller 40 after the trailing edge of the sheet passes the registration roller 40. It cannot be returned to the position. Therefore, when the driving time T is equal to or longer than the reference time TS, the operation of the image recording apparatus 100 is stopped assuming that the error in the paper transport position is excessive.

  When the drive time T is less than the reference time TS, the control unit 51 outputs drive data of the clutch 49 to the clutch driver 58 at a predetermined timing (S14, S15), and rotates the drive roller 41. The controller 51 outputs drive data to the motor driver 54 during the drive time T in a state where the drive roller 41 starts rotating and the sheet is conveyed to the image recording unit 30 by the registration roller 40 (S16). , 17). During the drive time T, the motor 47 rotates in the first rotation direction, and the registration roller 40 moves in the main scanning direction together with the support member 43.

  The drive data output from the control unit 51 to the motor driver 54 includes information for specifying the rotation direction of the motor 47. The first rotation direction is a direction in which the moving member 43 moves forward in the direction opposite to the direction in which the error occurs in the paper transport position. The registration roller 40 and the support member 43 move to the side where the registration roller 40 corrects the position of the sheet being conveyed.

  For example, as illustrated in FIG. 7, when the transport position of the paper M has an error of 2 mm on the right side with respect to the reference position SP, the registration roller 40 that is transporting the paper M is on the left side together with the support member 43. Move 2 mm. As a result, the sheet M is displaced 2 mm to the left, the conveyance position of the sheet M coincides with the reference position SP, and the image G is recorded at an appropriate position on the sheet M.

  When the drive time T elapses, the rotation of the motor 47 stops. When the trailing edge of the sheet passes the registration roller 40, the control unit 51 stops driving the clutch 47 and stops the rotation of the driving roller 41 (S18, S19). Then, the control unit 51 rotates the motor 47 in the second rotation direction during the driving time T (S20, S21). The second rotation direction is a direction opposite to the first rotation direction, and is a direction in which the registration roller 40 is moved back to the original position. The registration roller 40 returns to the original position together with the support member 43.

  By this processing, the sheet is not displaced while the image is recorded. Further, the next sheet does not contact the moving registration roller 40.

  When the driving time T is sufficiently shorter than the reference time TS, it is not always necessary to return the support member 43 to the original position. For example, every time the motor 47 is driven, the clockwise driving time T is integrated, and the counterclockwise driving time T is subtracted from the integrated value. When the absolute value of the calculation result reaches a predetermined time smaller than the reference time TS, the motor 47 is driven in the direction opposite to the sign of the calculation result. Thereby, the number of movements of the support member 43 can be reduced.

  FIG. 8 is a flowchart showing a procedure for changing the reference position and the image recording position by the control unit 51. The control unit 51 executes a change process for the reference position and the image recording position at a predetermined change timing. In this changing process, the correction value stored in the correction value storage area 52B is changed based on the error history.

  At the time of change processing, the control unit 51 checks the error history of each paper feed position stored in the error storage area 52A at the change timing (S31, S32). In the error history, when errors of substantially the same value are continuously generated at the same paper feed position, the stored content of the correction value storage area 52B is changed by the error value (S33, S34).

  As a result, the image recording position of the image recording unit 30 is changed to match the paper position, and an image is recorded at an appropriate position on the paper without displacing the paper.

  This change process can be performed not only when errors of substantially the same value are continuously generated, but also when there are differences in some or all of the errors in the same direction that are continuously generated. In this case, by changing the correction value according to the minimum value or the average value of a plurality of errors, the number of times the sheet is displaced or the cumulative value of the displacement amount can be reduced.

  The change timing is not included at least during execution of an image recording operation on one sheet in the image recording unit 30 and while the support member 43 is moved. For example, the change timing is set when the image recording apparatus 100 is started, when image recording on a predetermined number of sheets is completed, or when maintenance processing is executed.

1 is a schematic front sectional view showing a configuration of an image recording apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration in the vicinity of a registration roller 40 provided in the image recording apparatus 100. 3 is a block diagram illustrating a partial configuration of a control unit of the image recording apparatus 100. FIG. 4 is a flowchart illustrating a processing procedure of a control unit 51. 7 is a flowchart illustrating a processing procedure when a paper displacement process is performed by the control unit 51. 6 is a timing chart showing driving states of motors 47 and 48 and a clutch 49 and a detection signal state of a sensor 44 during a paper displacement process. FIG. 6 is a diagram illustrating a displacement state of a sheet by a sheet displacement process. 6 is a flowchart illustrating a procedure of a change process of a reference position and an image recording position by a control unit 51.

Explanation of symbols

30 Image Recording Unit 31 Photosensitive Drum 40 Registration Roller (Conveying Member)
41 Drive roller 42 Followed roller 43 Support member 44 Sensor (detection member)
45 Rack gear (displacement mechanism)
46 Pinion gear (displacement mechanism)
47 Motor (displacement mechanism)
Reference Signs List 51 control unit 52 storage unit 52A error storage area 52B correction value storage area 100 image recording device 300 image recording unit 400 paper feed unit 402 to 404 paper feed cassette

Claims (7)

A conveying member that conveys the recording material along a predetermined conveying direction; an image recording unit that records an image on the recording material; and a main scanning direction orthogonal to the conveying direction on the upstream side of the image recording unit in the conveying direction. A detection member for detecting the position of the recording material, and the recording material in the main scanning direction according to an error in the position of the recording material with respect to a reference position determined based on the image recording position of the image recording unit in the main scanning direction A displacement mechanism for displacing the detection member, an error storage unit for storing a history of a difference between the detection result of the detection member and the reference position, and correcting the image recording position and the reference position based on the stored contents of the error storage unit An image recording apparatus. The conveying member, after temporarily stops the recording material on the upstream side of the image recording unit in the conveying direction, conveying at a timing corresponding to the images recording operation of said image recording portion of the recording material to said image recording unit The image recording apparatus according to claim 1, wherein the image recording apparatus is a registration roller that starts the operation.   The image recording apparatus according to claim 1, wherein the detection member is disposed adjacent to the conveyance member on an upstream side of the conveyance member in the conveyance direction.   The image recording apparatus according to claim 1, wherein the detection member detects a position of an end portion of the recording material in the main scanning direction.   The displacement mechanism moves the conveying member in the main scanning direction after the conveying member starts conveying the recording material and before the recording material reaches the image recording unit. The image recording apparatus according to claim 1. The displacement mechanism includes a detection result of the detection member and the reference position after the registration roller starts conveying the recording material to the image recording unit and before the recording material reaches the image recording unit. The registration roller is moved to one side in the main scanning direction so as to eliminate the difference, and after the recording material passes through the registration roller and before the next recording material reaches the registration roller. The image recording apparatus according to claim 2, wherein the registration roller is moved to the other side in the main scanning direction . The displacement mechanism further includes a motor that moves the registration roller along the main scanning direction, and a calculation unit that calculates a driving time of the motor corresponding to a difference between the detection result and the reference position. ,
When the reference time indicating the time obtained by dividing the interval between the trailing edge of the recording material conveyed by the conveying member and the leading edge of the next recording material by the conveying speed is equal to or less than the driving time, The image forming apparatus according to claim 6, wherein the image recording operation and the conveyance operation of the recording material are stopped.

Images