JP2010039240A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily conform a rotational speed of rotary photosensitive members to a movement speed of an intermediate transfer member. <P>SOLUTION: A motor driving part 23 rotationally drives first and second motors M1 and M2. In each of the rotary photosensitive members 13c-13b turned by rotational drive of the first motor M1, a toner image is formed from a latent image by light beam scanning based on image data. The toner images are transferred from the rotary photosensitive members 13c-13b to the intermediate transfer member 15 in a process of movement to the auxiliary scanning direction based on the second motor M2. A rotational speed control part 25 controls the motor driving part 23 so that the rotary photosensitive members 13c-13b are rotationally driven at a speed lower than the movement speed of the intermediate transfer member 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming method, and relates to an improvement in a color image forming apparatus and an image forming method such as a copying machine and a multi function peripheral (MFP).

  As this type of color image forming apparatus, image forming units for forming cyan, magenta, yellow, and black color images are arranged at equal intervals along a belt-shaped intermediate transfer member, and the intermediate portions are conveyed. A tandem color configuration is well known in which a color image is sequentially transferred onto and transferred from each image forming unit onto a transfer body, and then color printing is performed by transferring and fixing the color image from the intermediate transfer body onto printing paper.

  Each of the four color image forming units forms a latent image by polarizing and scanning the light beam emitted from the laser based on the color image of each color from the image data on the rotating photoconductor with a polygon mirror. A color image is formed by attaching toner agents of respective colors.

  However, since the image forming apparatus uses four rotating photoreceptors corresponding to the respective colors, the individual toner images sequentially transferred from the rotating photoreceptors onto the intermediate transfer member include, for example, individual rotating photoreceptors or the like. Due to the crossing of these dimensions, a slight color shift is likely to occur.

  Therefore, as a method of correcting color misregistration generated in the toner image transferred from the individual rotating photoconductors to the intermediate transfer member, the toner on the intermediate transfer member is read by a reflective optical sensor, and the sub-scanning direction (conveying direction) is read. There has been proposed a technique for detecting a shift amount and eliminating a color shift by delaying or accelerating lighting of a light beam by one scanning unit.

  For example, the image forming apparatus disclosed in Japanese Patent Laid-Open No. 1-281463 (Patent Document 1) is of this type.

  That is, in this Patent Document 1, a position detection mark is transferred from a rotating photosensitive member onto an intermediate transfer member, a position detection mark is created, and a transfer image deviation is corrected based on a detection signal obtained by reading this mark. Correction control is performed.

When the transfer image misalignment correction technique according to Patent Document 1 is applied to a color image forming apparatus, in an image forming unit that forms and transfers an image of each color of black, yellow, magenta, and cyan, the traveling direction and progress of the intermediate transfer member A plurality of color misregistration detection patterns are formed over the entire circumference of the intermediate transfer body along a direction orthogonal to the direction, and each color misregistration detection pattern is calculated with a predetermined sampling period. However, it is considered that high image quality can be realized by correcting the position of the image forming unit and the image forming timing so that this becomes equal to a predetermined reference value.
JP-A-1-281468

  However, even if the transfer image misalignment correction technique according to Patent Document 1 described above is applied to an image forming apparatus, it is possible to correct the color misregistration and achieve high image quality by rotating the rotational speeds of the rotating photosensitive members and the intermediate transfer member. In practice, it is difficult to maintain each rotating photoconductor and intermediate transfer member at the desired rotation speed, and color misregistration is corrected accurately to achieve high image quality. It is difficult to do.

  Therefore, as a result of examining the structure of the image forming device and the characteristics of various motors, the present inventor has focused on the point that an electromagnetic motor other than a stepping motor is accelerated by a magnetic force and decelerated using a frictional force, etc. By controlling the movement of the intermediate transfer member with the rotating photosensitive member in contact with the stepping motor and controlling the rotation of the rotating photosensitive member with an electromagnetic motor other than the stepping motor, the rotational photosensitive member can be easily matched to the rotational speed of the intermediate transfer member. The present invention has been completed by finding that even if the moving speed of the intermediate transfer member fluctuates, it can be easily detected from the fluctuation of the rotating speed of the rotating photoconductor.

  The present invention has been made to solve such a problem, and it is easy to match the rotation speed of the rotary photoconductor and the rotation speed of the intermediate transfer body, thereby reducing the amount of transfer position deviation from the rotary photoconductor to the intermediate transfer body. An object of the present invention is to provide an image forming apparatus and an image forming method that can easily achieve high image quality in color.

  In order to solve such a problem, an image forming apparatus according to the present invention is a rotating photosensitive member that is rotated by a rotational drive of a first motor, and a toner agent from a latent image obtained by scanning a light beam based on image data. And the toner image formed on the rotating photosensitive member in the process of being moved in the sub-scanning direction by the second motor while the rotating photosensitive member is in contact with the rotating photosensitive member. The intermediate transfer member to be transferred, the motor driving unit that rotationally drives the first motor and the second motor, and the rotary photosensitive member are driven to rotate at a speed slightly slower than the moving speed of the intermediate transfer member. And a rotation speed control unit that controls the motor drive unit.

  In the image forming apparatus of the present invention, the second motor may be a stepping motor.

  In the image forming apparatus of the present invention, the first motor may be an electromagnetic motor other than a stepping motor.

  In the image forming apparatus of the present invention, the first motor may be a brushless motor.

  In the image forming apparatus of the present invention, when the rotation speed of the first motor is slower than the reference rotation speed related to the intermediate transfer member, the rotation speed control unit slows the rotation speed of the second motor. A configuration is also possible in which the motor driving unit is controlled so that when the rotation speed of the first motor is high, the motor driving unit is controlled to increase the rotation speed of the second motor.

  In the image forming apparatus of the present invention, the motor drive unit variably controls the rotation speed of the second motor by changing the frequency, and the rotation speed control unit changes the frequency to change the second speed. A configuration in which the rotational speed of the motor is variably controlled is also possible.

  In the image forming apparatus of the present invention, the rotating photosensitive member is individually arranged for four colors at a predetermined interval in the sub-scanning direction with respect to the intermediate transfer member, and a toner image of each color is placed on the intermediate transfer member. It is also possible to perform an overprinting configuration.

  An image forming method according to the present invention includes a toner image forming step of forming a toner image on a rotating photosensitive member rotated by a rotational drive of a first motor by a latent image obtained by scanning a light beam based on image data, and the rotation thereof. A transfer process for transferring the toner image formed on the rotating photosensitive member to an intermediate transfer member that is moved in the sub-scanning direction by the second motor while the photosensitive member is in contact, and the rotating photosensitive member And a rotational speed control step for controlling the rotation of the first motor so that the intermediate transfer member is moved at a speed slightly slower than the moving speed of the intermediate transfer member.

  In such an image forming apparatus according to the present invention, a toner image is formed by a latent image obtained by scanning a light beam based on image data on a rotating photosensitive member rotated by the rotational driving of the first motor, and the rotating photosensitive member. In the process of being moved in the sub-scanning direction by the second motor while the toner is in contact, the toner image formed on the rotating photosensitive member is transferred to the intermediate transfer member, and the rotating photosensitive member is rotated by the rotational speed control unit. Is rotated at a speed slightly slower than the moving speed of the intermediate transfer member, so that the rotational speed of the rotating photosensitive member and the rotating speed of the intermediate transfer member can be easily made constant, and the amount of transfer position deviation from the rotating photosensitive member to the intermediate transfer member can be easily achieved. Therefore, it is easy to achieve high color image quality.

  In the image forming apparatus of the present invention, when the second motor is a stepping motor, there is an advantage that the intermediate transfer member is not easily affected by the rotational speed of the rotating photosensitive member in contact with the stepping motor.

  In the image forming apparatus of the present invention, in the configuration in which the first motor is an electromagnetic motor other than the stepping motor, it is particularly easy to make the rotational speed of the rotating photosensitive member follow the moving speed of the intermediate transfer member.

  In the image forming apparatus according to the present invention, in the configuration in which the first motor is a brushless motor, in particular, the first motor itself can easily detect the rotational speed of the rotating photosensitive member.

  In the image forming apparatus of the present invention, when the rotation speed of the first motor is slower than the reference rotation speed related to the intermediate transfer member, the rotation speed control unit slows the rotation speed of the second motor. In the configuration in which the motor drive unit is controlled so that when the rotation speed of the first motor is high, the motor drive unit is controlled to increase the rotation speed of the second motor, the moving speed of the intermediate transfer member varies. However, the rotational speed of the rotating photoconductor can be driven in conjunction with this.

  In the image forming apparatus of the present invention, the motor drive unit variably controls the rotation speed of the second motor by changing the frequency, and the rotation speed control unit changes the frequency to change the second motor. In the configuration in which the rotational speed of the motor is variably controlled, fine adjustment of the moving speed of the intermediate transfer member is easy.

  In the image forming apparatus of the present invention, the rotating photosensitive member is individually arranged for four colors at a predetermined interval in the sub-scanning direction with respect to the intermediate transfer member, and a toner image of each color is placed on the intermediate transfer member. In the superimposing transfer configuration, even in a tandem configuration in which four color light beams are irradiated onto the rotating photoconductors of each color, it is easy to match the speed of each rotating photoconductor and the intermediate transfer member, and color misregistration in the sub-scanning direction is easy. Can be adjusted and the configuration is not complicated.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings. The image forming method according to the present invention will be described in the course of describing the image forming apparatus of the present invention.

  First, a general configuration of the image forming apparatus A will be briefly described.

  FIG. 1 is a schematic block diagram showing the configuration of an image forming apparatus A according to the present invention.

  In FIG. 1, the image forming apparatus A includes an image reading unit 3, a storage unit 5, an operation panel unit 7, a printing unit 9, and a communication unit 11 connected to the main control unit 1. For example, a multifunction device. The image forming apparatus A has other constituent elements than these, but is not a main part of the present invention, and thus description and illustration thereof are omitted. The function of the main control unit 1 will be described later.

  The image reading unit 3 is a known scanner that optically reads an image from a document under the control of the main control unit 1 and generates electronic image data subjected to filter processing or the like as a print job. The pages are sequentially stored in the storage unit 5.

  Under the control of the main control unit 1, the storage unit 5 stores image data from the image reading unit 3 or the communication unit 11, a predetermined reference rotation speed (reference rotation speed) for the intermediate transfer member 15 described later, and the main control unit 1. It is a readable / writable hard disk (HDD) that stores an operation application program, operation screen information for operating the image forming apparatus A, and the like.

  The operation panel unit 7 is an input / output unit that also serves as, for example, a known liquid crystal display and a touch switch arranged in the image forming apparatus A. Under the control of the main control unit 1, the operation state and various data in the image forming apparatus A And a function for receiving an operation instruction input to the apparatus A and a predetermined reference rotational speed setting input.

  The printing unit 9 is a known print engine that inputs image data from the storage unit 5 under the control of the main control unit 1, develops the image data into image data, and forms an image by performing full color or monochrome printing on printing paper. Details will be described later.

  The communication unit 11 is connected to an external electronic device such as an image forming apparatus (both not shown) via a network under the control of the main control unit 1, and an external image according to a predetermined image data transmission protocol. This is an interface for transmitting and receiving e-mails and facsimiles to and from the forming apparatus.

  The main control unit 1 includes a CPU, a ROM that stores a startup program for the CPU, and the like. The image reading unit 3, the storage unit 5, the operation panel unit 7, the printing unit 9, and the application program stored in the storage unit 5 It consists of a control computer that controls the communication unit 11 and has the following functions.

  Based on the application program and setting information (not shown), the main control unit 1 stores the image data from the image reading unit 3 and the communication unit 11 in the storage unit 5 and passes the stored image data to the printing unit 9. A print control (image formation control) function and an image data communication function with an external image forming apparatus.

  Next, the printing unit 9 described above will be described with reference to FIGS.

  In FIG. 2, rotating photoreceptors 13c, 13m, 13y, and 13b that form individual color images of cyan, magenta, yellow, and black are conventionally known cylindrical rotating drums having the same shape. Are arranged at equal intervals and in parallel with each other, and the lower ends thereof are in contact with the intermediate transfer body 15.

  Each of the rotating photoconductors 13c to 13b is rotationally driven by a first motor M1 described later in the same direction as the conveyance direction of the intermediate transfer body 15. In FIG. 2, only the first motor M1 for the rotating photoreceptor 13m is shown (the same applies hereinafter).

  For example, the upper ends of the rotating photoconductors 13c to 13b are exposure positions Pc, Pm, Py, and Pb where a light beam, which will be described later, is subjected to polarization scanning. An electrostatic latent image is formed on the outer peripheral surface of 13b, and a color image is visually formed on the electrostatic latent image portion by a toner agent from cyan, magenta, yellow and black color toner cassettes (not shown). It is like that.

  The intermediate transfer member 15 is a known endless belt that has substantially the same axial width as the rotating photosensitive members 13c to 13b and is looped around the rollers 17a and 17b and the like, and a second motor M2 described later. Therefore, the conveyance displacement is made in the sub-scanning direction orthogonal to the scanning direction.

  In FIG. 2, the pressure contact portion side (transfer position side described later) of the intermediate transfer body 15 with the rotating photosensitive members 13 c to 13 b is transported and displaced from the right to the left in the drawing.

  On the intermediate transfer member 15, cyan, magenta, yellow, and black color images from the respective rotating photosensitive members 13 c to 13 b are sequentially superimposed and transferred in the conveyance process in the sub-scanning direction. Reference numerals pc, pm, py, and pb in FIG. 2 are transfer positions at which cyan, magenta, yellow, and black color images are transferred to the intermediate transfer body 15.

  The exposure positions Pc, Pm, Py, and Pb of the rotary photoconductors 13c to 13b are so transferred that the cyan, magenta, yellow, and black color images from the rotary photoconductors 13c to 13b are transferred onto the same position of the intermediate transfer body 15. For example, the polarization scanning timing in FIG. 4 considers the rotation period of the rotating photoconductors 13c to 13b, and the moving period during which the intermediate transfer member 15 moves from the transfer position pc of each rotating photoconductor 13c to the transfer position pm of the rotating photoconductor 13m. Are set to be delayed in order.

  It is to be noted that the color image on the intermediate transfer member 15 is transferred and fixed on a printing paper (not shown) at a position downstream of the rotary photosensitive member 13b and printed as in the conventional case.

  FIG. 3 is a schematic view showing a configuration for forming, for example, a black color image together with the main part of the present invention in the image forming apparatus according to the present invention.

  That is, the polygon mirror 19 is disposed above the rotating photosensitive member 13b with the lens L therebetween, and the light emitting element 21b that emits a black laser beam based on image data and emits a light beam is a mirror of the polygon mirror 19. It is arranged toward the peripheral surface.

  The light beam from the light emitting element 21b is emitted toward a polygon mirror 19 that rotates at a constant speed by a brushless motor (not shown), reflected by the mirror peripheral surface of the polygon mirror 19, converged by the lens L, and the first motor M1. Is subjected to polarization scanning for each line at the exposure position Pb of the rotary photosensitive member 13b that is rotationally driven by the above-described operation.

  The first motor M1 is a known electromagnetic motor, for example, a brushless motor, which is rotationally driven by a frequency drive signal from a motor drive unit 23, which will be described later, and the first motor M1 is detected by detecting the magnetic pole of the rotor unit (not shown). A detection unit S that detects the rotation speed of the motor M <b> 1 is provided, and the detected rotation speed (detected rotation speed) from the detection unit S is output to the rotation speed control unit 25.

  The motor drive unit 23 has a function of rotating the first motor M1 as described above and controlling the rotation of the second motor M that rotates the roller 17b, for example.

  The second motor M1 is, for example, a known stepping motor that is rotationally driven by a frequency drive signal from the motor drive unit 23 and moves the intermediate transfer member 15 through the rotation of the roller 17b.

  The motor drive unit 23 has a function of variably controlling the rotation speed (number of rotations) by changing the frequency of the drive signal applied to the first and second motors M1 and M2, and the first motor M1. In contrast, it has a function of starting to rotate so that the outer peripheral speed of the rotating photosensitive member 13b (13c, 13m, 13y) is slightly slower than the moving speed of the intermediate transfer member 15.

  By the way, when the outer peripheral speed of the rotating photoconductor 13b (13c, 13m, 13y) is slightly higher than the surface speed of the intermediate transfer member 15 (surface speed of the rotating photoconductor> surface speed of the intermediate transfer member), contact is made by frictional force. The surface speed of the intermediate transfer member 15 is increased by the surface speed of the rotating photosensitive member 13b (13c, 13m, 13y).

  In addition, the surface speed of the intermediate transfer member 15 tends to be difficult to manage due to the variation in the diameter of the four rotating photoconductors 13b (13c, 13m, 13y) in the tandem configuration.

  Therefore, in order to avoid this, it is ideal that the surface speed of the rotating photoconductor 13b (13c, 13m, 13y) and the surface speed of the intermediate transfer body 15 are equal. In the present invention, however, speed management is performed. Therefore, the surface speed of the rotating photoconductor 13b (13c, 13m, 13y) is slightly slower than the surface speed of the intermediate transfer body 15.

  As described above, the rotating photosensitive member 13b (13c, 13m, 13y) that is in contact with the intermediate transfer member 15 and started to rotate at a slightly lower speed starts to rotate in conjunction with the intermediate transfer member 15 at a constant speed.

  The rotation speed control unit 25 includes a CPU, a ROM that stores a startup program for the CPU, and the like. The rotation speed control unit 25 is operated by an application program stored in the storage unit 5 or is operated by the main control unit 1 as described below. Have

  That is, the rotation speed control unit 25 reduces the rotation speed of the second motor M2 when the rotation speed obtained from the detection unit S of the first motor M1 is slower than the reference rotation speed related to the intermediate transfer member 15. The motor drive unit 23 is controlled, and when the rotation speed of the first motor M1 is higher than the reference rotation speed, the motor drive unit 23 is controlled to increase the rotation speed of the second motor M2.

  Here, the reference rotational speed is a speed at which the rotating photosensitive member 13b (13c, 13m, 13y) in contact with the intermediate transfer body 15 rotates stably at a constant speed together with the intermediate transfer body 15, and as described above in advance. Is set.

  When the rotation speed of the first motor M1 is slower than the reference rotation speed, the movement speed of the intermediate transfer member 15 is increased for some reason. Conversely, the rotation speed of the first motor M1 is the reference speed. When the rotational speed is higher than the rotational speed, the moving speed of the intermediate transfer member 15 is slow.

  The light emission control unit 27 has a function of controlling light emission of the light emitting elements 21b of the respective colors at the above-described light emission timing based on the image data from the main control unit.

  Since cyan, magenta, and yellow have the same configuration, description and illustration are omitted.

  Next, the operation of the image forming apparatus A of the present invention will be described with reference to the flowchart of FIG.

  The program starts, the motor drive unit 23 activates the second motor M2 to rotate the intermediate transfer member 15 in step S1, and the motor drive unit 23 activates the first motor M1 in step S2. Thus, the rotating photosensitive members 13c to 13b are rotated at a slightly lower speed than the intermediate transfer member 15.

  Subsequently, in step S3, the rotational speed control unit 25 detects the rotational speed of the first motor M1, and the process proceeds to step S4, where the rotational speed control unit 25 determines whether or not the speed of the intermediate transfer member 15 has changed, that is, It is determined whether or not the rotational speeds of the rotating photoconductors 13c to 13b are deviated from the reference rotational speed.

  If there is no change, the process proceeds from step S4 to step S5, and the rotation speed control unit 25 drives the second motor M2 to rotate at the same rotation speed via the motor drive unit 23 and returns to step S3. Repeat S7.

  When the rotational speed of the photoconductors 13c to 13b is slower than the reference rotational speed, the process proceeds from step S4 to step S6, and the rotational speed control unit 25 outputs the rotational drive signal whose frequency is decreased in step S6 to the motor drive unit 23. In step S5, the motor drive unit 23 reduces the rotation speed of the second motor M2 to drive the rotation, and the process returns to step S3.

  When the rotational speed of the rotating photoconductors 13c to 13b is higher than the reference rotational speed, the process proceeds from step S7 to step S7, and the rotational speed control unit 25 outputs the rotational drive signal whose frequency is increased in step S7 to the motor drive unit 23. In step S5, the motor drive unit 23 increases the rotation speed of the second motor M2 to drive the rotation, and the process returns to step S3. Thereafter, the program exits when a predetermined condition is satisfied.

  As described above, the image forming apparatus according to the present invention is the rotating photosensitive members 13c to 13b that are rotated by the rotational drive of the first motor M1 that is a brushless motor, and the toner is generated from the latent image by the scanning of the light beam based on the image data. In the process of moving in the sub-scanning direction by a second motor M2 comprising a stepping motor in a state where the rotary photoconductors 13c to 13b on which toner images are formed with the agent and the rotary photoconductors 13c to 13b are in contact with each other. The intermediate transfer member 15 to which the toner images formed on the rotating photosensitive members 13c to 13b are transferred, the motor driving unit 23 that rotationally drives the first and second motors M1 and M2, and the rotating photosensitive members 13c to 13c. A rotational speed control unit 25 for controlling the motor drive unit 23 so as to rotationally drive the rotational speed of 13b at a speed slightly slower than the moving speed of the intermediate transfer member 15; It is equipped with.

  Therefore, the rotational speeds of the rotating photoconductors 13c to 13b are easily driven at a speed equal to the rotational speed of the intermediate transfer body 15, and the transfer position deviation amount from the rotating photoconductors 13c to 13b to the intermediate transfer body 15 can be reduced. The shift amount can be easily corrected, and color image quality can be easily improved.

  In addition, the intermediate transfer member 15 can be moved from the rotating photosensitive members 13c to 13b without applying unnecessary load. From this point, the intermediate transfer member 15 is easily and stably displaced.

  In addition, since the second motor M2 is a stepping motor, there is an advantage that the intermediate transfer member 15 is not easily affected by the rotational speed of the rotating photosensitive members 13c to 13b that are in contact with the second motor M2, and the first motor M1 is not a stepping motor. Therefore, it is easy to link the rotation speed of the first motor M1 to the second motor M2.

  Further, when the rotation speed of the first motor M1 is slower than the reference rotation speed, the rotation speed control unit 25 controls the motor driving unit 23 so as to decrease the rotation speed of the second motor M2, and the first When the rotation speed of the motor M1 is faster than the reference rotation speed, the motor drive unit 23 is controlled so as to increase the rotation speed of the second motor M2. Thus, the rotational speeds of the rotating photoconductors 13c to 13b can be driven.

  Moreover, the motor drive unit 23 variably controls the rotation speed of the second motor M2 by changing the frequency, and the rotation speed control unit 25 variably controls the rotation speed of the second motor M2 by changing the frequency. The moving speed of the intermediate transfer member 15 can be finely adjusted by slightly changing the frequency drive signal.

  When a brushless motor is used as the first motor M1, in particular, since the brushless motor has a rotation speed detection mechanism, the first motor M1 itself can easily detect the rotation speed of the rotating photoconductor, It is difficult to make the configuration complicated.

  By the way, in the above-described embodiment according to the present invention, the description has been made with the tandem configuration in which a color image is formed by irradiating the rotating photoconductors 13c to 13b with four light beams based on image data.

  However, the image forming apparatus according to the present invention can be implemented in the rotational speed control of the individual rotating photosensitive members 13c to 13b, and is not necessarily limited to the tandem configuration having the four-color rotating photosensitive members 13c to 13b. Absent.

  By the way, referring to the image forming method according to the present invention, a toner image is formed on the rotating photosensitive members 13c to 13b rotated by the rotation driving of the first motor M1 by the latent image by the scanning of the light beam based on the image data. Toner image forming step and an intermediate transfer member 15 moved in the sub-scanning direction by the second motor M2 in a state where the rotating photosensitive members 13c to 13b are in contact with each other, formed on the rotating photosensitive members 13c to 13b. A transfer step for transferring the toner image, and a rotation speed control step for controlling the rotation of the first motor M1 so that the rotating photosensitive members 13c to 13b are moved at a speed slightly slower than the moving speed of the intermediate transfer member 15. Therefore, it is possible to obtain the same effect as that of the image forming apparatus described above.

1 is a schematic block diagram showing an outline of an image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating a schematic configuration of a printing unit of an image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating a schematic configuration of a printing unit of an image forming apparatus according to the present invention. 6 is a flowchart illustrating an operation of the image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main control part 3 Image reading part 5 Memory | storage part 7 Operation panel part 9 Printing part 11 Communication part 13c, 13m, 13y, 13b Rotating photoconductor 15 Intermediate transfer body 17a, 17b Roller 19 Polygon mirror 21b Light emitting element 23 Motor drive part 25 Rotational speed control unit 27 Light emission control unit A Image forming apparatus (multifunction machine)
L lens M1 first motor M2 second motor Pc, Pm, Py, Pb exposure position pc, pm, py, pb transfer position

Claims (8)

A rotating photoreceptor that is rotated by the rotation of the first motor, wherein a toner image is formed by a latent image obtained by scanning a light beam based on image data;
An intermediate transfer member to which the toner image formed on the rotating photosensitive member is transferred in the process of being moved in the sub-scanning direction by the second motor while the rotating photosensitive member is in contact with the rotating photosensitive member;
A motor drive unit that rotationally drives the first motor and the second motor;
A rotational speed control unit for controlling the motor drive unit to rotationally drive the rotational photosensitive member at a speed slightly slower than the moving speed of the intermediate transfer member;
An image forming apparatus comprising: The image forming apparatus according to claim 1, wherein the second motor is a stepping motor. The image forming apparatus according to claim 1, wherein the first motor is an electromagnetic motor other than a stepping motor. The image forming apparatus according to claim 3, wherein the first motor is a brushless motor. The rotational speed control unit controls the motor driving unit to slow down the rotational speed of the second motor when the rotational speed of the first motor is slow relative to a reference rotational speed related to the intermediate transfer member; 5. The image forming apparatus according to claim 1, wherein when the rotation speed of the first motor is high, the motor drive unit is controlled to increase the rotation speed of the second motor. The motor drive unit variably controls the rotation speed of the second motor by varying the frequency, and the rotation speed control unit variably controls the rotation speed of the second motor by varying the frequency. The image forming apparatus according to claim 5. 2. The rotating photosensitive member is individually arranged for four colors at a predetermined interval in the sub-scanning direction with respect to the intermediate transfer member, and the toner image of each color is superimposed and transferred onto the intermediate transfer member. The image forming apparatus according to any one of? 6. A toner image forming step of forming a toner image on a rotating photosensitive member rotated by rotation of the first motor by a latent image obtained by scanning a light beam based on image data;
A transfer step of transferring the toner image formed on the rotary photosensitive member to an intermediate transfer member moved in the sub-scanning direction by a second motor in a state where the rotary photosensitive member is in contact;
A rotational speed control step for controlling the rotation of the first motor so that the rotational photosensitive member is moved at a speed slightly slower than the moving speed of the intermediate transfer member;
An image forming method comprising:

Images