JP2008165194A - Electrophotographic photosensitive drum, electrophotographic image forming apparatus and method for manufacturing electrophotographic photosensitive drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple structure for achieving a seamless digital photosensitive drum having an exposure light source and a photosensitive member which are integrated with each other. <P>SOLUTION: The electrophotographic photosensitive drum includes a self-luminous device portion, a functional separation portion and a photosensitive portion. The self-luminous device portion includes a first electrode wire layer including multiple first electrode wires provided in a circumferential direction of a cylindrical substrate and arrayed in a longitudinal direction of the cylindrical substrate so as to be separated from each other by an insulating member, and the first electrode wire is annularly formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photoreceptor that is a latent image forming device, and more particularly to an electrophotographic photoreceptor drum that is a photoreceptor device in which an exposure source is integrated. The present invention also relates to an electrophotographic image forming apparatus using the electrophotographic photosensitive drum. Furthermore, the present invention relates to a method for manufacturing the electrophotographic photosensitive drum.

  In the electrophotographic process, after uniformly charging the photosensitive member, a desired pattern is exposed based on image information to form a charge density distribution (latent image) on the surface of the photosensitive member, which is developed with toner. It is a visible image.

  Laser printers and LED printers are widely used as products applying the electrophotographic process.

  The laser printer uses a semiconductor laser as an exposure source and scans the photosensitive member by reflecting the laser beam with a rotating polygon mirror.

  Here, in the following description, the main scanning direction refers to the drum longitudinal direction (drum bus direction) with respect to the rotary drum type photoreceptor. The sub-scanning direction refers to the drum circumferential direction with respect to the rotating drum type photoreceptor.

  The LED printer is a system in which LED light-emitting pixels of the required number of pixels are arranged in the laser scanning direction (main scanning direction) of the laser printer, and this is imaged on the surface of the photoreceptor by an imaging element.

Since the LED printer does not involve main scanning like a laser printer, it has a feature that image position accuracy in the main scanning direction is good.

  However, in both the laser printer and the LED printer, the sub-scanning accuracy depends on the relative position and relative speed between the photosensitive drum and the exposure source. For this reason, for example, pitch unevenness occurs in the sub-scanning direction due to vibration of the exposure source, eccentricity of the photosensitive drum, and fluctuations in rotational speed.

  As a means for increasing the accuracy of this sub-scanning, the relative speed between the exposure source and the photosensitive member is eliminated. That is, it is conceivable to integrate the exposure source and the photosensitive member. The following method has been taken as an example of this integration.

1) Example of flat plate photoreceptor device in which a photosensitive layer is laminated on a light emitting element through an intermediate buffer layer. Patent Document 1 discloses a high hardness α-Si photosensitive layer (amorphous silicon) on a thin film EL layer (electroluminescence layer). Introduction of an intermediate buffer layer has been introduced as a method for laminating the photosensitive layer.

2) Example of flat photosensitive device in which α-Si photosensitive layer is laminated on light emitting array layer via insulating layer In Patent Document 2, a pixel TFT (Thin-Film-Transistor: Thin Film Transistor) matrix is formed on a glass substrate Top emission configuration of inorganic LED is introduced.

3) Example of photosensitive drum in which photosensitive layer is laminated on EL device having pixel TFT In Patent Document 3, a device transfer method is introduced as a method of constructing an EL device including a TFT layer on a cylindrical substrate.
JP 05-2221018 A Japanese Patent Laid-Open No. 06-095456 JP 2001-18441 A

  Here, a rotating drum type photosensitive body in which an exposure source and a photosensitive body are integrated, that is, an exposure source integrated that eliminates a factor in image accuracy deviation not only in the main scanning direction but also in the sub scanning direction by forming pixels on the photosensitive body. The drum is hereinafter referred to as a digital photosensitive drum.

  This method using a digital photosensitive drum is a direction of technological evolution even in view of the transition of technology from LED spot scanning to LED array in which main scanning is fixed, and further from pixel array to pixel matrix method in which sub scanning is fixed. Is reasonable.

  However, considering the usage as a printer, the conventional digital photosensitive drum system is inconvenient in terms of continuous printing. Here, the continuous printing refers to continuous printing on continuous paper (for example, roll paper) or the like, and a small-diameter drum (drum circumference <print length area) in sheet paper printing.

  The reason for this will be described. In the configurations of Patent Document 1 and Patent Document 2, since a flat exposure source-photoconductor integrated device is used, it is difficult to cope with continuous printing.

  Further, in the digital photosensitive drum configuration of Patent Document 3, since the self-luminous device is wound around the drum base, seams (joints) can be formed in the drum circumferential direction. That is, as shown in FIG. 3 of Patent Document 3, when a planar pixel array is formed and then adhered to a cylindrical substrate, a seam is always formed. For this reason, in the seam portion, the pixel array becomes discontinuous and the image is defective, so that it is not possible to print in a continuous area exceeding the drum circumference.

  Accordingly, an object of the present invention is to realize a seamless digital photosensitive drum that can be mounted as an electrophotographic photosensitive drum in an electrophotographic image forming apparatus with a simple configuration. Another object of the present invention is to provide an electrophotographic image forming apparatus using the seamless digital photosensitive drum. Furthermore, it is providing the manufacturing method of the seamless digital photoconductor drum.

A typical configuration of the electrophotographic photosensitive drum according to the present invention for achieving the above object is as follows.
A cylindrical substrate;
A self-luminous device portion provided on the cylindrical base, and extending in a ring shape in the circumferential direction of the cylindrical base and separated by an insulator in the longitudinal direction of the cylindrical base. A second electrode line including a first electrode line layer including a first electrode line and a plurality of second electrode lines extending in a longitudinal direction of the cylindrical base and separated and arranged by an insulator in a circumferential direction of the cylindrical base; A self-luminous device unit comprising an electrode line layer and an EL light emitting layer, wherein the first electrode line layer, the EL light emitting layer, and the second electrode line layer are laminated in this order on the cylindrical substrate;
A functional separation unit comprising a transparent insulating layer provided on the self-luminous device unit, and a transparent conductive layer provided on the transparent insulating layer;
A photoreceptor provided on the transparent conductive layer;
The first electrode line is provided with an annular shape without a seam.

Further, a typical configuration of the electrophotographic image forming apparatus according to the present invention for achieving the above object is as follows:
An electrophotographic image forming apparatus comprising: a charging device that charges a rotatable electrophotographic photosensitive drum; and a developing device that develops a latent image formed on the electrophotographic photosensitive drum with a developer.
The electrophotographic photosensitive drum is:
A cylindrical substrate;
A self-luminous device portion provided on the cylindrical base, and extending in a ring shape in the circumferential direction of the cylindrical base and separated by an insulator in the longitudinal direction of the cylindrical base. A second electrode line including a first electrode line layer including a first electrode line and a plurality of second electrode lines extending in a longitudinal direction of the cylindrical base and separated and arranged by an insulator in a circumferential direction of the cylindrical base; A self-luminous device unit comprising an electrode line layer and an EL light emitting layer, wherein the first electrode line layer, the EL light emitting layer, and the second electrode line layer are laminated in this order on the cylindrical substrate;
A functional separation unit comprising a transparent insulating layer provided on the self-luminous device unit, and a transparent conductive layer provided on the insulating layer;
A photoreceptor provided on the transparent conductive layer;
The first electrode line is provided with an annular shape without a seam.

And the typical structure of the manufacturing method of the electrophotographic photosensitive drum according to the present invention for achieving the above object is as follows:
In the method for producing an electrophotographic photosensitive drum,
A first electrode line layer including a plurality of first electrode lines extending in a ring shape in the circumferential direction of the cylindrical substrate and separated by an insulator in the longitudinal direction of the cylindrical substrate on the cylindrical substrate; A second electrode line layer including a plurality of second electrode lines extending in the longitudinal direction of the cylindrical substrate and separated and arranged by an insulator in the circumferential direction of the cylindrical substrate, and an EL light emitting layer. A step of forming a self-luminous device part, the step of laminating the first electrode line layer, the EL light emitting layer, and the second electrode line layer in this order on the cylindrical substrate;
Forming a functional separation unit comprising a transparent insulating layer and a transparent conductive layer on the self-luminous device part, wherein the transparent insulating layer and the transparent conductive layer are arranged in this order after the self-luminous device part is formed; And forming with
Forming a photoconductor portion on the function separating portion, and forming the photoconductor portion after forming the transparent conductive layer;
The first electrode wire is provided in an annular shape without a seam by processing a cylindrical member from the outer periphery.

  A seamless digital photosensitive drum can be realized by the configuration and manufacturing method of the electrophotographic photosensitive drum of the present invention. In addition, according to the configuration of the electrophotographic image forming apparatus equipped with this seamless digital photosensitive drum, it is possible to use a small-diameter digital photosensitive drum whose peripheral length is shorter than the printing length of the print medium to be supported in the specification. The image forming apparatus can be downsized.

[Example 1]
(1) Image Forming Unit FIG. 1 is a schematic cross-sectional view showing a schematic configuration of an electrophotographic image forming apparatus A in this embodiment. FIG. 2 is an enlarged view of the image forming unit 1 and the intermediate transfer belt unit (ITB unit, hereinafter referred to as belt unit) 7 in the image forming apparatus A. FIG. 3 is an exploded schematic view of first to fourth process cartridges (hereinafter referred to as cartridges) PY, PM, PC, and PK mounted on the image forming unit 1 and the intermediate transfer belt unit 7. FIG. 4 is an enlarged schematic cross-sectional view showing a schematic configuration of one cartridge P (Y, M, C, K).

  The image forming apparatus A of this embodiment is a full-color digital electrophotographic printer that is a 4-drum tandem type and uses an endless belt as an intermediate transfer member.

  In this printer A, a sheet-like recording material S is used to generate a full-color image or a mono-color image corresponding to electrical image data (image information signal) input from an external device (host device) C connected to the main body control circuit unit B. Can be formed and output (printed out).

  The external device C is a personal computer, an image reader, a facsimile, or the like.

  The main body control circuit unit (controller) B exchanges various electrical information signals with the external device C. It also controls electrical information signals input from image forming process devices and sensors, command signals to image forming process devices and the like, and predetermined image forming sequence control. Operation control of the entire printer is executed according to a control program and a reference table stored in the ROM or RAM.

  The image forming unit 1 is disposed on the upper side of the belt unit 7 and is a horizontal tandem in which four first to fourth cartridges PY, PM, PC, and PK are arranged in order from the left side to the right side in the drawing. It is a configuration. Each cartridge P (Y, M, C, K) can be individually attached to and detached from the unit frame (not shown) of the image forming unit 1.

  The first to fourth cartridges PY, PM, PC, and PK respectively form yellow, magenta, cyan, and black color toner images, which are color separation component images of a full color image. In this embodiment, cartridges for forming yellow, magenta, cyan, and black color toner images are arranged in the order in which image formation is performed. However, the color order in which image formation is performed is not limited to the above, and cartridges in any color order. Can be an array.

  Referring to FIG. 4, each of the cartridges P (Y, M, C, K) is an electrophotographic process mechanism having the same configuration, and each drum type electrophotographic photosensitive member is the center of the image forming process. 2 (hereinafter referred to as a drum).

  Each drum 2 is a digital photosensitive drum integrated with an exposure source and a latent image, in which a photosensitive layer is laminated on a light emitter element matrix layer. It is driven to rotate at a predetermined angular velocity in the counterclockwise direction of the arrow about the support shaft 2a. The digital photosensitive drum 2 will be described later.

  Each cartridge P (Y, M, C, K) is an electrophotographic process means acting on the drum 2, and includes a charging roller (charging device) 3, a developing device (developing device) 4, and a drum cleaning device (cleaning device). ) 5. However, the developing device 4 of the first cartridge PY contains yellow toner as a developer. The developing device 4 of the second cartridge PM contains magenta toner as a developer. The developing device 4 of the third cartridge PC contains cyan toner as a developer. The developing device 4 of the fourth cartridge PK contains black toner as a developer.

  Each charging roller 3 is provided with a conductive rubber roller portion on a metal shaft portion, arranged in parallel with the drum 2 and brought into pressure contact with a predetermined pressing force, and is driven by the rotation of the drum 2. Then rotate. A DC voltage of −700 V, for example, is applied as a dark potential Vd to the substrate potential of the drum 2 as a charging bias from a power source (not shown) to the metal shaft portion of the charging roller 3. As a result, a uniform surface charge distribution with a potential of about −450 V can be formed on the surface of the drum 2 having the dielectric coating film at the charging portion a which is the contact portion between the drum 2 and the charging roller 3. it can.

  With respect to the drum surface having the uniform surface charge distribution, it corresponds to the image data with the exposure point being the position between the charged portion a and the developing portion b, in FIG. The drum light emitting element is turned on to expose the spot pattern from the back surface of the photoreceptor. The developing portion b is a portion where the drum 2 is subjected to a developing action by the developing device 4, and in this embodiment, the developing roller 4a is in contact with the drum 2.

  In the photosensitive layer of the drum 2 exposed by lighting the light emitting element, carriers are generated in the carrier generation layer (CGL), and holes are formed in the carrier transport layer (CTL) by the action of the electric field due to the uniformly charged surface charge. Move and counter the surface charge. As a result, the exposed portion (bright potential) Vl of the photoreceptor of the drum 2 is about −50V, and the surface charge density distribution of the unexposed portion Vd (dark potential) is about −400V. That is, an electrostatic latent image is formed on the surface of the drum 2.

  In this way, in the first cartridge PY, an electrostatic latent image corresponding to the yellow color separation component image of the full-color image is formed on the surface of the rotating drum 2, and the latent image is converted into yellow by the developing device 4. Developed as a toner image.

  In the second cartridge PM, an electrostatic latent image corresponding to the magenta color separation component image of the full-color image is formed on the surface of the rotating drum 2, and the latent image is developed as a magenta toner image by the developing device 4. The

  In the third cartridge PC, an electrostatic latent image corresponding to the cyan color separation component image of the full-color image is formed on the surface of the rotating drum 2, and the latent image is developed as a cyan toner image by the developing device 4. The

  In the fourth cartridge PK, an electrostatic latent image corresponding to the black color separation component image of the full-color image is formed on the surface of the rotating drum 2, and the latent image is developed as a black toner image by the developing device 4. The

  Each developing device 4 employs a so-called one-component nonmagnetic contact developing method in this embodiment. A developing roller 4a having a conductive rubber roller portion is provided, and the developing roller 4a is arranged in parallel with the drum 2 and is brought into pressure contact with a predetermined pressing force. The developing roller 4a is driven independently from the drum 2 by a driving mechanism (not shown), and the tangential speed direction at the developing portion b which is a contact portion with the drum 2 is the same, but the tangential speed between the developing roller 4a and the drum 2 is the same. The ratio is about 2: 1.

  To the developing device 4 of each cartridge P (Y, M, C, K), toner is supplied in a fixed amount from a toner tank (toner cartridge) 6 set on the top of each cartridge at a predetermined control timing. The toner supplied to the developing device 4 is contact-charged by the interaction between the developing roller 4a and the supplying roller 4b and the trimmer 4c arranged in contact with the developing roller 4a. Then, the toner is applied to the surface layer of the developing roller 4a, and the mass per unit area of the toner application is regulated to a desired value, and is conveyed to the developing portion b by the rotation of the developing roller 4a. A predetermined developing bias is applied to the developing roller 4a from a power supply unit (not shown). For example, a developing bias of, for example, V = −200 V is applied between the developing roller 4 a and the base of the drum 2. Then, under the above-described latent image conditions, the latent image can be developed with toner with the development contrast Vc = 150V and the back contrast Vbc = 200V to form a toner image on the drum 2.

  The belt unit 7 includes an endless and flexible dielectric intermediate transfer belt (hereinafter referred to as a belt) 8. The belt 8 is provided by suspending three substantially parallel rollers, a driving roller 9, a tension roller 10, and a secondary transfer counter roller 11, which are rotatably supported by a belt unit frame 7a. As a member, it is suspended between these rollers. Four primary transfer rollers 12 corresponding to the cartridges P (Y, M, C, and K) are disposed on the inner side of the belt 8. Each primary transfer roller 12 is provided with a roller portion of conductive rubber on the metal shaft portion, and is arranged substantially in parallel with the corresponding drum 2, and a predetermined pressing against the lower surface portion of the drum 2 with the belt 8 interposed therebetween. Press contact is made with pressure. A contact nip portion between the drum 2 and the belt 8 is a primary transfer portion d. These primary transfer rollers 12 are also arranged so as to be rotatably supported with respect to the belt unit frame 7a.

  When the image forming process is executed, the belt 8 is driven to rotate at a predetermined speed in the clockwise direction of the arrow. The speed reference at the time of execution of the image forming process of the drum 2 of each cartridge P (Y, M, C, K) is synchronized with the tangential speed of the belt 8. In this embodiment, a drive transmission method using a toothed belt is used in order to synchronize the reference speed with the image formation of each cartridge P (Y, M, C, K). That is, the transfer drive pulley on the primary transfer roller shaft of each cartridge P (Y, M, C, K) is driven by the toothed belt transmitted with power from the pulley on the belt drive shaft. Further, the driving force is transmitted to the drum shaft 2 a, that is, the drum 2 by meshing the transfer roller gear and the drum gear.

  With respect to the drums 2 of the first to fourth cartridges PY, PM, PC, and PK, yellow, magenta, cyan, and black color toner images, which are color separation component images of full-color images, are respectively subjected to predetermined control. Formed at the timing. The yellow toner image formed on the drum 2 of the first cartridge PY is primarily transferred onto the belt 8 that is driven to rotate at the primary transfer portion d. The magenta toner image formed on the drum 2 of the second cartridge PM is superimposed on the yellow toner image on the belt 8 and primarily transferred at the primary transfer portion d. The cyan toner image formed on the drum 2 of the third cartridge PC is primarily transferred to the yellow toner image + magenta toner image on the belt 8 at the primary transfer portion d. The black toner image formed on the drum 2 of the fourth cartridge PK is primarily transferred to the yellow toner image + magenta toner image + cyan toner image on the belt 8 at the primary transfer portion d. That is, four color toner images of yellow, magenta, cyan, and black are sequentially superimposed and superimposed (multiple) transferred onto the belt 8 to form a full-color unfixed toner image (mirror image). The

  In the primary transfer portion d of each cartridge P (Y, M, C, K), the primary transfer of the toner image from the drum 2 to the belt 8 is performed with respect to each primary transfer roller 12 by a respective power supply unit (not used). This is done by the action of an electric field of a predetermined transfer bias applied from the figure.

  In each cartridge P (Y, M, C, K), the untransferred toner on the drum 2 after the toner image is transferred to the belt 8 becomes waste toner from the drum surface by the urethane rubber cleaning blade 5a of the drum cleaner 5. It is scraped off. The scraped-off waste toner is collected by a waste toner screw 5b in a waste toner container (not shown) provided in the image forming unit 1.

  The full-color unfixed toner image synthesized and formed on the belt 8 as described above is conveyed by the subsequent rotation of the belt 8 and is a secondary transfer portion e which is a contact portion between the belt 8 and the secondary transfer roller 13. To. The secondary transfer roller 13 is provided with a roller portion made of conductive rubber on the metal shaft portion, and is arranged in parallel with the secondary transfer counter roller 11 so as to sandwich the belt 8 and press contact with a predetermined pressing force. The belt 8 rotates in the forward direction in the belt moving direction at substantially the same speed as the speed of the belt 8.

  On the other hand, together with a request for an image forming (printing) operation, a sheet-like recording material (recording) stacked in a paper feeding cassette 14 disposed in the lower part of the printer main body by a separation feeding roller 16 in the paper feeding / conveying unit 15. Paper) Only the topmost recording material of S is separated. The recording material S passes through the conveying roller pair 17 and is sent to the registration unit 18. The registration unit 18 sends the recording material S to the secondary transfer portion e at a timing at which the position of the leading end portion of the toner image on the belt 8 and the position of the leading end portion of the recording material S are synchronized at the secondary transfer portion e. The recording material S that has entered the secondary transfer site e is nipped and conveyed at the secondary transfer site e, and a predetermined transfer bias is applied to the secondary transfer roller 13 from a power supply unit (not shown) during the conveyance process. Thus, the batch transfer of the four-color superimposed toner images on the belt 8 is sequentially received.

  The recording material S that has passed through the secondary transfer site e is separated from the surface of the belt 8 and introduced into the hot-pressure type fixing unit 20 by the transport unit 19. The unfixed full-color toner image on the recording material S is melted, mixed and fixed on the recording material by applying heat and pressure by the fixing unit 20. Then, it passes through the vertical conveyance unit 21 and the paper discharge unit 22 and is discharged onto the face-down paper discharge tray 23 as a full-color image formed product.

  Further, the untransferred toner on the belt 8 after the toner image is transferred to the recording material S is removed and collected by the belt cleaner 24.

  The above is the case of the full color image forming mode. In the mono-color image forming mode such as monochrome, the designated color cartridge performs the image forming operation. Other cartridges rotate the drum 2 but no image forming operation is performed.

  In FIG. 1, a multi paper feed unit (manual paper feed unit) 25 is disposed on the right side surface of the printer A. The multi-feed unit 25 is arranged to be openable and closable with respect to the printer main body. When not in use, the multi-feed unit 25 is converted into a closed state with respect to the printer main body, and when in use, it is converted into an open state from the printer main body. The In FIG. 1, a face-up paper discharge tray 26 is disposed on the left side of the printer A. The tray 26 is freely openable and closable with respect to the printer body. When the tray 26 is not used, the tray 26 is converted into a closed state. When the tray 26 is used, the tray 26 is converted into an opened state.

  The printer A of the present embodiment has four units of the secondary transfer roller 13, the paper feeding / conveying unit 15, the registration unit 18, and the multi paper feeding unit 25 as one unit. It has a drawer configuration that can be pulled out from the unit side. An image forming unit 1 is mounted on the drawer. When exchanging the toner, this can be easily done by pulling out the drawer and exchanging the toner tank 6 on the drawn image forming unit 1. Exchange of each cartridge P (Y, M, C, K) can be similarly easily performed by pulling out the drawer and exchanging the cartridge on the drawn image forming unit 1. In the printer of this embodiment, the toner capacity of the toner tank (toner cartridge) is A4: 3000 sheets in terms of 5% printing, and the durable number of each cartridge P (Y, M, C, K) is 50000 sheets. is there.

(2) Digital photosensitive drum 2
5A is a longitudinal sectional view of the drum 2, FIG. 5B is an enlarged view of one end portion side (drive side), and FIG. 5C is an enlarged view of the other end portion side (non-drive side). FIG. 6 is a perspective view of the driving unit and the phase detection unit of the drum 2.

  The digital photoconductor drum 2 is an exposure source-latent image forming integrated rotary drum in which a self-light-emitting device portion serving as a light-emitting element matrix layer, a function separation portion, and a photoconductor portion are laminated on a cylindrical substrate. Type photosensitive device. Cylindrical flanges 31a and 31b are fitted into the two openings of the drum 2 by being press-fitted coaxially with the drum 2, fixed, and the drum shaft 2a is inserted between the flanges 31a and 31b. . Both flanges 31a and 31b are integrally fixed to the drum shaft 2a. The axis of the drum 2 and the axis of the drum shaft 2a are coaxially matched. Both ends of the drum shaft 2a protrude outward from the flanges 31a and 31b, and bearings 32a and 32b are fitted on the protruding shafts, respectively. In addition, a drum gear G2 is coaxially fitted to the driving shaft and is integrally fixed to the drum shaft 2a. An encoder wheel portion 33 for phase detection is provided on the outer peripheral portion (outer diameter portion) of the end of the flange 31a on the drive side. The bearings 32a and 32b are respectively held by the frame bodies Pa and Pb of the process cartridge P (Y, M, C, and K).

  In a state where the process cartridges P (Y, M, C, and K) are attached to the printer main body, the drum gears G2 of the respective process cartridges are respectively transferred to the corresponding primary transfer rollers as shown in FIG. It meshes with the roller gear G12. Then, when the driving force is transmitted from the transfer roller gear G12 to the drum gear G2, the drum shaft 2a is rotationally driven. That is, the drum 2 is rotationally driven. As described above, the rotational force of the belt driving roller 9 of the belt unit 7 is transmitted to each primary transfer roller 12 via the power transmission mechanism of the pulley and the toothed belt, and rotates. The transfer roller gear G12 is integrally fixed to the shaft 12a of the primary transfer roller 12 so as to be coaxial and integrally rotates with the primary transfer roller 12. The rotation of the transfer roller gear G12 is transmitted to the drum gear G2, and the drum 2 is rotationally driven. The speed reference at the time of execution of the image forming process of the drum 2 of each cartridge P (Y, M, C, K) is synchronized with the tangential speed of the belt 8.

  FIG. 7 is a schematic diagram of the layer structure of the digital photosensitive drum 2 in this embodiment. The drum 2 is an exposure source-latent image formed by laminating three functional layers of a self-luminous device section 50 as a light emitting element matrix layer, a function separating section 60, and a photoreceptor section 70 on a cylindrical substrate 40. This is a rotary drum type photosensitive device integrated with a formation. FIG. 7 is a cross section in a plane including the drum axis of the drum 2 and including one of the second electrode lines arranged in parallel to the axis.

  Here, for convenience, in the following description, an annular first electrode line that is included in the self-light-emitting device unit 50 and makes one round in the circumferential direction of the cylindrical substrate is referred to as a “signal line”, and is also included in the self-light-emitting device unit 50. The linear second electrode line in the longitudinal direction of the cylindrical substrate is referred to as a “scan line”.

(2-1) Cylindrical substrate 40
In this embodiment, the cylindrical base 40 uses an aluminum cylinder (hereinafter referred to as a drum cylinder).

(2-2) Self-luminous device unit 50
The light-emitting device unit 50 includes a control circuit (control unit) 51 that controls a voltage applied to the signal line (first electrode line) and the scanning line (second electrode line), and a signal line layer (first electrode line layer). ) 52, EL light emitting layer 53, and scanning line layer (second electrode line layer) 54. The controller 51, the signal line layer 52, the EL light emitting layer 53, and the scanning line layer 54 were laminated in this order from the inside to the outside with respect to the outer peripheral surface of the drum cylinder 40.

  The signal line layer 52 is a layer of a signal line group (sub-scanning signal line group) including a plurality of signal lines 52e. The signal line 52e extends in an annular shape in the circumferential direction of the cylindrical base. The respective signal lines 52e are separated by an insulator 52g and arranged at equal intervals in the longitudinal direction of the cylindrical substrate.

  The scanning line layer 54 is a layer of a scanning line group (main scanning signal line group) including a plurality of scanning lines 54a. The scanning line 54a extends in the longitudinal direction of the cylindrical substrate. Each scanning line 52a is separated by an insulator 54b ((e) in FIG. 11B) and arranged at equal intervals in the circumferential direction of the cylindrical base.

  The ring-shaped signal line group of the signal line layer 52 and the linear scanning line group of the scanning line layer 54 form a form stretched in the form of a vertical and horizontal grid, and the intersection of each signal line 52e and each scanning line 54a is It becomes a pixel part.

  The function of the control circuit 51 is ON / OFF control of each signal line 52e of the signal line layer 52 and each scanning line 54a of the scanning line layer 54. The gate 51b of the final driving TFT 51d is controlled to turn on / off the signal line 52e and the scanning line 54a. That is, each pixel is controlled independently. The source electrode of the driving TFT 51d is connected to the electrode pad 51e. The driving TFT 51d in FIG. 7 is a transistor in the signal line control circuit, and the driving TFT 51d in FIG. 11 is a transistor on the scanning line control circuit side.

  The control circuit 51 is obtained by transferring a control circuit formed on a glass substrate by a poly-Si process onto the drum cylinder 40 by a so-called device transfer method. 51a is a polysilicon layer (insulating layer) of a circuit formed by a poly-Si process, and is bonded to the surface of the drum cylinder 40. A driving driver (a constant current circuit, a lighting time control circuit, a shift register, a buffer, etc.) for the driving TFT 51d is formed on the same device.

  The signal line layer 52 includes interlayer insulating layers (insulating films) 52a and 52b, a plurality of annular signal lines 52e, and a through-hole electrode (large) 52c that is an interlayer electrode connected to the signal line 52e and the electrode pad 51e of the driving TFT 51d. And a through-hole electrode (small) 52d.

  The signal line 52e in the present embodiment is an Ag electrode having a width of 10 μm, and is a schematic diagram of a vertical and horizontal lattice structure of an annular signal line group of the signal line layer 52 and a linear signal line group of the scanning line layer 54 in FIG. In this way, the drum cylinder 40 has an annular shape that makes one round. The annular signal line 52e is separated by a partition wall 54b, which is an insulator, and is arranged in a large number at predetermined equal intervals in the drum cylinder longitudinal direction. In this embodiment, the mutual interval between the annular signal lines 52e is about 42 μm (pixel resolution 600 dpi), and 5120 lines (A4 paper portrait printing compatible) match the annular axis line of the signal line 52e with the drum axis line 2a. Are arranged to be. Each signal line 52e is connected to the electrode pad 51e of the driving TFT 51d through the through-hole electrodes 52d and 52c.

  The EL light emitting layer 53 constitutes a charge injection type fluorescent light emitting element using organic EL. In this embodiment, the signal line 52e side is a cathode made of metal electrode (Ag), and the scanning line 54a side is made an anode made of metal oxide (ITO). Therefore, a four-layer structure in which an electron transport layer (ETL), a light emitting layer (EML), a hole transport layer (HTL), and a hole injection layer (HIL) are stacked in this order from the signal line 52e side to the scanning line 54a side. did.

  The scanning line 54a of the scanning line layer 54 is a linear pattern electrode having a width of 10 μm and extending in the longitudinal direction of the drum cylinder. Multi-arrayed. Each scanning line 54a is formed of a transparent conductive oxide (ITO). In this embodiment, the mutual interval between the scanning lines 54 a is about 42 μm (pixel resolution 600 dpi), and 1800 (φ24 drum, phase angle 0.2 degree) scanning lines 54 a are in the scanning line layer 54 with the drum axis. They are arranged with parallel or crossing angles. Each scanning line 54a is connected to the electrode pad 51e of the driving TFT 51d through the through-hole electrodes 54c and 52c as shown in FIG. 11B (e).

(2-3) Function separation unit 60
The function separating unit 60 includes a transparent insulating / gas barrier layer (hereinafter referred to as a transparent insulating / barrier layer) 61 that is a transparent insulating layer that electrically insulates the light-emitting device unit 50 and the photosensitive member unit 70, and this layer. And a transparent conductive layer (transparent conductive film) 62 provided on 61. The transparent insulating / barrier layer 61 is a multilayered laminated film of an organic polymer film and a metal oxide thin film (Al ₂ O ₃ ). The transparent conductive layer 62 is formed by depositing ITO on the surface (cylindrical outer peripheral surface side) of the transparent insulating / barrier layer 61. As a result, the functional separation layer 60 maintains a high gas barrier performance with a visible light transmittance of 85% (λ = 520 nm).

(2-4) Photosensitive member 70
The photoconductor section 70 has an undercoat layer (UCL) 71, a carrier generation layer (CGL) 72, a carrier transfer layer (CTL) 73, and a protective layer 74 in order on the transparent conductive layer 62 of the function separating section 60. Are organic photoconductors (OPC).

  The basic structure of the above-mentioned digital photosensitive drum 2 of this embodiment is: base body / control circuit / signal line / EL layer / scanning line / transparent insulating layer / transparent conductive layer (ITO) / OPC. A signal line driver which is a control circuit unit for controlling the voltage of the signal line is divided into a plurality of parts. The signal line driver and the signal line have a vertical contact structure with a through hole. A scanning line driver, which is a control circuit unit for controlling the scanning line voltage, is disposed outside the image area of the drum 2. The scanning line is ITO or ITO + auxiliary electrode and forms a top emission structure.

  In the digital photosensitive drum 2 of the present embodiment, the self light emitting device unit 50 includes a control circuit 51, and a signal line layer 52 on the control circuit 51. That is, the distance between the control circuit 51 and the signal line 52e is shorter than the distance between the control circuit 51 and the scanning line 54a. Since the electric signal is less likely to attenuate when the signal line 52e is closer to the control circuit 51, the signal line 52e can be stably controlled.

  If the organic EL layer 53 exists between the signal line 52e and the scanning line 54a, the EL layer 53 can emit light by the PM method. Therefore, when the control circuit 51 is provided on the substrate 40, 1) it is possible to control light emission in the order of the layer structure of the control circuit 51, the signal line layer 52, the EL layer 53, and the scanning line layer 54 from the substrate 40 side. It is. In addition, it is possible to perform light emission control with the layer structure in the order of the control circuit 51, the scanning line layer 54, the EL layer 53, and the signal line layer 52 from the base 40 side. In other words, it is possible to control light emission in either of the layer configurations 1) and 2). However, it can be said that 1) is better than 2). This is because the signal line 52e is controlled at a higher speed (shorter cycle) than the scanning line 54a. That is, at which position in the longitudinal direction of the drum 2 the EL layer 53 is illuminated is determined by the image data signal, and the signal line 52e must be controlled in accordance with the image data. On the other hand, the scanning line 54a is in charge of which position in the circumferential direction of the drum 2 shines the EL layer 53, and the control of the scanning line 54a is not changed by the image data. Thus, by arranging the signal line 52e that is controlled at a high speed (short cycle) near the control circuit 51, the attenuation of the data signal can be suppressed. In particular, since the control circuit 51 is provided on the base body 40, the signal line 52e and the control circuit 51 can be arranged close to each other.

  In the digital photosensitive drum 2 of the present embodiment, each scanning line 54a of the scanning line layer 54 is formed of a transparent conductive oxide (ITO). Since the scanning line 54 a is transparent, it does not prevent the light emitted from the EL layer 53 from going to the photosensitive member 70. As described above, the organic EL layer 53 is between the signal line 52e and the scanning line 54a. Therefore, either the signal line 52e or the scanning line 54a is always formed on the EL layer 53. Here, since the signal line 52e is formed in an annular shape, it is difficult to make an ITO signal line by sputtering or the like. On the other hand, since the scanning line 54a is linearly provided in the longitudinal direction of the drum 2, the ITO electrode line can be formed more easily than the annular signal line 52e. Therefore, the scanning line 54a is formed on the EL layer 53, and further, the scanning line 54a is formed of a transparent conductive oxide (ITO) so that the light emitted from the EL layer 53 is not disturbed. The body part 70 can be irradiated.

  With the simple means described above, an exposure source-photoreceptor integrated digital photosensitive drum can be mounted during the configuration of a conventional electrophotographic image forming process. Further, the writing position correction or the sub-scanning registration correction in the in-line color machine can be performed without being affected by fluctuations in the image forming speed.

(3) Manufacturing Process of Digital Photosensitive Drum 2 FIGS. 9 to 11 show an outline of a manufacturing process of the digital photosensitive drum 2 in this embodiment. FIG. 9 is a flow chart of the outline of the manufacturing process, and FIGS. 10 to 11 are process schematic diagrams of the manufacturing process.

  FIG. 10 is a diagram in which the digital photosensitive drum 2 is cut in the longitudinal direction so as to include the scanning line 54a. The left and right sides in FIG. 10 correspond to the longitudinal direction of the digital photosensitive drum 2.

  FIG. 11 is a diagram in which the digital photosensitive drum 2 is cut in the circumferential direction so as to include a scanning line control circuit 51 provided at an end portion in the longitudinal direction for driving the scanning line 54a. The left and right sides in FIG. 11 correspond to the circumferential direction of the digital photosensitive drum 2.

  FIG. 18 is a plan view of the digital photosensitive drum 2. FIG. 10 is a view as seen from the direction A in FIG. FIG. 11 is a view seen from the direction B in FIG.

Process P1: Formation of Control Circuit Using a poly-Si process on a base substrate (glass substrate), a signal line / scanning line control circuit (device) that is a circuit that includes signal line driving and I / F (interface) ).

Process P2: Device Transfer The device is peeled off from the original substrate, and the device is transferred onto the outer peripheral surface of the drum cylinder 40. That is, the control circuit 51 is formed on the outer peripheral surface of the drum cylinder 40 ((a) in FIG. 10A).

  The device is bonded and fixed so as to wrap around the outer peripheral surface of the drum cylinder 40. At this time, in order to absorb the tolerance of the outer diameter dimension of the drum cylinder 40 and the winding peripheral length of the device, a seam having a gap of 250 μm or less remains in the winding portion of the device.

Process P3: Formation of Insulating Layer 52a Flange 31a and 31b (FIG. 5) are attached to both ends of the drum cylinder 40. An organic polymer layer is formed as an interlayer insulating layer 52a on the outer peripheral surface of the drum where the control circuit 51 is formed ((b) of FIG. 10A).

  In this example, a 10 μm polyimide film was coated by dipping as the insulating layer 52a. By this step, the seam portion is filled, and the drum outer peripheral surface becomes a seamless continuous curved surface.

Process P4: Formation of Signal Line Layer 52 A via hole (large through hole) 52f is formed in the insulating layer 52a by laser processing toward the center of the signal line electrode pad 51e of the drive TFT 51d of the control circuit 51 ((c in FIG. 10A). )).

  Next, the via hole 52f is filled with a conductive paste. That is, the through-hole electrode (large) 52c is formed ((d) in FIG. 10B).

  Also, on the scanning line drive circuit side, the formation of the through hole (large) 52f for the scanning line 54a and the formation of the through hole electrode 52c are similarly performed ((a) and (b) of FIG. 11A).

  The outer peripheral surfaces of the insulating layer 52a and the through-hole electrode 52c are polished and smoothed by a CMP process.

  Next, by a photolithography process, a plurality of signal lines (first electrode lines) 52e are formed in a circular shape without a cut in the circumferential direction of the drum cylinder, separated from each other by an insulator 52g and arranged in the longitudinal direction of the drum cylinder. ((E), (f) of FIG. 10B).

  52f is a through hole (small), and 52g is an insulating partition for signal line patterning. A through-hole electrode 52d is formed in the through-hole (small) 52f portion, and is formed simultaneously with the formation of the signal line 52e. Each signal line 52e is connected to the electrode pad 51e of the driving TFT 51d through the through-hole electrodes 52d and 52c.

A through hole (small) 52f is also formed on the scanning line driving circuit side ((c) in FIG. 11A).
In this way, the signal line layer 52 is formed by a process performed from the outside on a cylindrical member (a drum cylinder to which the device is transferred). Therefore, the signal line 52e can be formed on the ring without seams. There is no formation of a seam as in the conventional case where a sheet-like self-luminous device is produced and then wound around a cylindrical member.

Process P5: Formation of the organic EL layer 53 On the surface of the signal line layer 52, a plurality of partition walls 54b of an insulator for scanning line patterning are linear in the drum cylinder longitudinal direction and at a predetermined interval and width in the drum cylinder circumferential direction. ((G) in FIG. 10B, (d) in FIG. 11B).

  Next, the organic EL layer 53 is formed by vapor deposition ((g) in FIG. 10C).

Process P6: Formation of Scan Line Layer 54 A scan line 54a is formed into a pattern by sputtering ITO using a shadow mask (FIG. 10C (i), FIG. 11B (e)). At this time, a through-hole electrode (interlayer electrode) 54c between the scanning line 54a and the through-hole (large) 52c on the scanning line driving circuit side is also formed simultaneously.

  By the processes P1 to P6, the self-light emitting device unit 50 is formed on the outer peripheral surface of the drum cylinder 40 by sequentially stacking the control circuit 51, the signal line layer 52, the EL light emitting layer 53, and the scanning line layer 54.

Process P7: Formation of Transparent Insulation / Barrier Layer 61 On the outer peripheral surface of the self-luminous device part 50 formed as described above, as the transparent insulation / barrier layer 61, a polymer (PEN) layer and a metal oxide (Al ₂ O ₃ ) layers are alternately deposited by a continuous vapor deposition process ((j) in FIG. 10D).

Process P8: Formation of Transparent Conductive Layer 62 On the outer peripheral surface of the transparent insulating / barrier layer 61, ITO is deposited as the transparent conductive layer 62 by sputtering ((k) in FIG. 10D).

  By the processes P7 and P6 described above, the function separating section 60 having gas barrier properties, surface conductivity, and visible light permeability is formed on the outer peripheral surface of the self-luminous device section 50.

Process P9: Formation of Photosensitive Member 70 On the outer peripheral surface of the function separating portion 60, as the photosensitive member 70, an undercoat layer (UCL) 71, a carrier generation layer (CGL) 72, a carrier transfer layer (CTL) are formed by dipping coating. ) 73 and a protective layer 74 are formed to form an organic photoreceptor (OPC) layer.

  All processes of film formation, photolithography, and through-hole electrode formation for forming the self-luminous device section 50, the function separating section 60, and the photoreceptor section 70 are processes from the drum outer peripheral surface side.

  By the manufacturing processes P1 to P9 described above, the small-diameter digital photosensitive drum 2 that is seamless in the drum circumferential direction can be realized.

  That is, a discontinuous portion, that is, a seam remains on the drum circumference until the signal line / scanning line control circuit of the process P2 is transferred to the device and formed on the drum cylinder 40. However, the drum outer diameter portion after the interlayer insulating layer 52a is formed in the process P3 has a seamless cylindrical surface shape. Further, in the subsequent process, the signal line 52e is formed in an annular shape, and the scanning line 54a is arranged symmetrically with respect to the drum rotation axis.

  With the above configuration, a seamless pixel matrix having light emitting points (pixels) near the intersection of the signal line 52e and the scanning line 54a is formed. That is, a seamless and small-diameter digital photosensitive drum 2 is manufactured. Thereby, the size of the printer main body can be reduced by including the exposure device. The stability of the output image against vibration and load fluctuation is improved.

(4) Driving Method of Digital Photosensitive Drum 2 FIG. 12 is a block diagram of a driving circuit for the digital photosensitive drum 2.

  Transmission and reception of electrical information signals including image data between the main body control circuit unit B of the printer A and the control circuit unit on the side of the digital photosensitive drum 2 that is rotationally driven are performed by a wireless interface.

  In this embodiment, the light emitting pixels on the drum 2 side are driven by passive matrix (PM) driving by sequentially selecting the scanning lines 54a. That is, the drive circuit sequentially selects the scanning lines 54a of the scanning line layer 54, and drives the signal lines 52e of the signal line layer 52 in synchronization with the scanning lines 54a. As a result, the circuit is driven in a line sequential manner in which a light emitting pixel portion in the vicinity of a point where the scanning line 54a and the signal line 52e intersect is caused to emit light to form a light emission pattern corresponding to image data.

  In this embodiment, the number of scanning lines 54a is 1,800, the scanning line interval is about 42 μm (resolution 600 dpi), the image forming speed is 120 mm / s, and the steady scanning cycle is about 352 μs (scanning frequency 2.8 KHz). Select sequentially.

  The scanning line potential is controlled to be a positive potential when selected, and to 0 V (GND) when not selected. By controlling ON / OFF of the signal line in synchronization with the selection of the scanning line, a light emission pattern corresponding to the image data on the scanning line is formed. In this embodiment, the signal line 52e is set to about 0V (GND) when not selected and + 5V when not selected. By setting the non-selection potential of the scanning line 54a and the selection potential of the signal line 52e substantially equal, light emission on the non-selected scanning line is prevented.

  The phase detection configuration of the digital photosensitive drum 2 in this embodiment will be described with reference to FIG. FIG. 6 shows a part of the belt unit 7 near the driving side end of the digital photosensitive drum 2 and the object on which the drum 2 is positioned.

  The drum 2 is provided with an encoder wheel portion 33 for phase detection at an outer diameter portion of a driving side drum flange 31 a fixed coaxially with the drum 2 at an end portion of the drum cylinder 40. Therefore, if the drum 2 is driven to rotate, the encoder wheel unit 33 also rotates together with the drum 2. The rotation center axis of the encoder wheel portion 33 is provided coaxially with the center axis of the drum 2.

  The phase division pattern of the encoder wheel unit 33 maintains the phase relationship with the scanning line 54 a of the scanning line layer 54 of the drum 2.

  The encoder wheel portion 33 is a black Cr etching pattern formed on the outer diameter portion of an aluminum alloy drum flange 31a. In this embodiment, the number of decompositions is 1800 divisions (each AB phase is divided into 900 divisions), and zero inspection is performed. Has outgoing Z phase.

On the other hand, the phase detector 34 is a reflection type photodetector with Z-phase detection, and is fixed to the belt unit frame 7a. The phase division pattern of the encoder wheel unit 33 is detected by the phase detector 34. The detection signal of the phase detector 34 is input to the phase detection circuit internal counter (FIG. 12) of the main body control circuit section B. In this embodiment, as shown in FIG. The phase detection point by the phase detector 34 is in the vicinity of the lowermost portion in the vertical direction on the drum cross section corresponding to the primary transfer site d.

  The rotation angle of the drum 2 is obtained by adding the A / B phase output detected by the phase detector 34 to the internal counter of the main body control circuit unit B. The internal counter operates in a mode that is reset when the Z phase that is the reference position of the drum 2 is detected.

  When the image formation start trigger is issued, the main body control circuit B detects the current phase of the drum 2 from the current value of the internal counter in the scanning line selection control unit (FIG. 12), and the scanning line to be driven for exposure. 54a is selected. That is, at the time of image formation, the main body control circuit unit B calculates the phase of the drum 2 with respect to the belt unit 7 (printer main body) based on the output signal from the phase detector 34, and determines the scanning line to be driven based on this value. . The write scanning line 54a on the drum is selected from the current phase of the drum 2 at the time of writing trigger. Writing scanning is performed in synchronization with the current phase pulse of the drum 2.

  FIG. 13 shows the drive timing. One strobe cycle corresponds to a scanning line selection cycle. In this embodiment, all the signal lines 5120 are divided into five segments for control. For this reason, the light emission is time-division driven by sequentially driving each segment with a time of about 50 μs.

  The luminescent pixel data is latched in the LINEn + 1 data in the frame in which the scanning line LINEn emits light. Light emission data (4-bit data including light emission time information) of 1024 segments is transferred to the signal drive circuit in a time division manner and latched into the buffer.

  FIG. 14 shows a block diagram of data transfer. The segment (Segment) is selected by the address (ADDR) generated by the control unit, and the data (DATA) is transferred to the corresponding segment. Here, the frequency of the data (DATA) transfer clock (CLK) is 20 MHz.

  With the above configuration, in the self-light-emitting device unit 50, in the vicinity of a portion where the scanning line 54a of the selected pixel intersects with the signal line 52e by line-sequential selection of the scanning line 54a and ON / OFF driving of the signal line 52e in synchronization therewith. A fluorescent spot is generated by the organic EL layer 53. By directly exposing the photoconductor portion 70 laminated thereon with the fluorescent spot, a charge density distribution on the photoconductor surface, that is, an electrostatic latent image is formed.

  The detection of the rotational phase of the drum 2 with respect to the printer main body will be further described with reference to FIGS.

  For example, as shown in FIG. 15A, the arrangement of the charged portion a and the developing portion b with respect to the drum 2 is set at a position 120 degrees apart. An intermediate position between the charged part a and the developing part b is set as an exposure point c. A position opposite to the exposure point c by 180 degrees is defined as a transfer site d. The rotational angular velocity of the drum 2 is 120 degrees / second. There is only one position detection patch (so-called home position detection) M between the area 2) and the area 3) of the drum 2, and the position detection means 34 detects the patch at a position corresponding to the transfer site d. Suppose there is.

  In FIG. 15A, when the position detection unit 34 detects the patch M at the transfer site d, it can be seen that there is a region 1) between the charging site a and the development site b. Since exposure must be performed between the charged part a and the development part b, the main body control unit B determines that the area 1) is an area where a latent image can be formed by exposure, as shown in (b) of decision 15. ) Will be exposed after 1 second has passed since the patch M is detected.

  As described above, when exposure is started based on time, there is no problem when the rotation speed of the drum 2 is constant. However, when the rotation speed of the drum 2 is suddenly decreased, there is a possibility that the exposure is performed although there is a portion that cannot be exposed yet (a portion that cannot be written yet) as shown in FIG. is there. That is, there is a possibility that the latent image cannot be formed well due to fluctuations in the angular velocity of the drum 2.

  Therefore, with respect to the encoder wheel unit 33 of the above embodiment, the interval of the division pattern for detecting the phase (the pattern corresponds to the patch M in FIG. 15) is set to 120 degrees or less of the interval between the charged portion a and the developing portion b. As a result, the influence of the speed fluctuation of the drum 2 is reduced. In FIG. 16, phase detection patterns (patches) M1, M2, and M3 are provided at the boundaries (each 120 degrees) of the areas 1), 2), and 3).

  In FIG. 16A, when the position detection unit 34 detects the patch M3 at the transfer site d, it is understood that there is a region 1) between the charging site a and the development site b.

  Then, as shown in FIG. 16B, when the next pattern M2 comes after 1 second, it is understood that there is a region 2) between the charged portion a and the developing portion b.

  In this way, by providing the patterns M1, M2, and M3, it is possible to determine which region of the drum 2 is currently between the charged portion a and the developing portion b, so that the timing of exposure is not a reference based on time. This can be performed on the basis of the patterns M1, M2, and M3. That is, exposure is started with the detection of the patterns M1, M2, and M3 as a trigger.

  With this method, even if the rotation speed of the drum 2 suddenly decreases, the next pattern does not reach the transfer site d, that is, the position detection means 34 as shown in FIG. It can be seen that there is a portion that cannot be exposed yet in the area 2).

  Therefore, it is possible to stop the exposure of the area 2), and it is possible to prevent the situation where the exposure is performed even though there is a portion that cannot be exposed yet.

  Of course, as the number of divisions of the pattern of the encoder wheel unit 33 is increased, the accuracy of grasping the position of the drum 2 is increased. For example, as shown in FIG. 17A, if the number of patterns is M1 to M10, the rotational phase position of the drum 2 can be grasped by 10 divisions. Therefore, ideally, if the encoder wheel unit 33 has the same number of patterns as the number of scanning lines 54a included in the scanning line layer 54, the scanning lines 54a and the patterns can be grasped in a one-to-one correspondence.

  In FIG. 16A, if the pattern interval is made smaller than the angle between the charged part a and the developing part b, it is possible to grasp which area of the drum 2 is at least between the charging part a and the developing part b. I was able to do it. Further, when it is desired to perform exposure only in specific areas of the charging part a and the development part b, it is effective to increase the number of patterns. For example, if it is not preferable to expose immediately after the charging site a or just before the development site b, and there is an exposure suitable region between the charging site a and the development site b, if the pattern is divided into a large number, Exposure can be performed in the exposure suitable region. For example, as shown in FIG. 17B, when the exposure suitable region has a central angle of 30 °, 360 ° ÷ 30 ° = 12, and the pattern of the encoder wheel portion 33 is divided into 12 parts. Exposure can be performed in an exposure suitable region.

  As described above, as the interval between the drum rotation phase detection patterns of the encoder wheel portion 33, that is, the number of phase detection decomposition increases, exposure is performed in a specific region (exposure suitable region) between the charged portion a and the development portion b. Is effective.

  Thus, the interval between the drum rotation phase detection patterns (the number of phase detection decompositions) of the encoder wheel unit 33 is set to be equal to or less than the interval between the charging portion a and the development portion b of the drum 2. Thus, the exposure source-photoreceptor integrated digital photosensitive drum can be mounted with a simple means configuration during the configuration of the conventional electrophotographic image forming process. Further, the writing position correction or the sub-scanning registration correction in the in-line color machine can be performed without being affected by fluctuations in the image forming speed.

  As described above, in the present invention, a digital photosensitive drum in which electrode lines are seamless can be manufactured. Since the electrode lines are seamless, it is possible to form an image longer than the circumference of the digital drum photoconductor. Therefore, a small-diameter digital photosensitive drum can be produced. Thereby, the size of the printer main body can be reduced by including the exposure device. Further, since it is a digital photosensitive drum, the stability of the output image against vibration and load fluctuation is improved.

(5) Others 1) Although the image forming apparatus of the embodiment is an inline color image forming apparatus, the image forming apparatus can be a one-drum type color image forming apparatus. Also, a monocolor image forming apparatus can be provided.

  2) The charging means of the drum 2 is not limited to contact charging using the charging roller of the embodiment. A non-contact type corona discharger can also be used.

  3) The developing means of the drum 2 is not limited to the one-component nonmagnetic contact developing system of the embodiment. Various types of contact or non-contact development using a one-component or two-component developer can be used.

  4) A cleaner-less image forming apparatus in which the transfer residual toner is simultaneously cleaned by the developing unit and the dedicated cleaning unit is omitted can be provided.

Schematic cross-sectional view showing schematic configuration of electrophotographic image forming apparatus of embodiment Enlarged view of the image forming unit and intermediate transfer belt unit in this image forming apparatus Exploded schematic view of the first to fourth process cartridges and the intermediate transfer belt unit mounted on the image forming unit Enlarged cross-sectional schematic diagram showing schematic configuration of one cartridge (A) is a longitudinal sectional view of the digital photosensitive drum, (b) is an enlarged view of one end side (drive side), and (c) is an enlarged view of the other end side (non-drive side). The perspective view which looked at the drive part and phase detection part of a digital photosensitive drum Schematic diagram of the layer structure of the digital photosensitive drum in the embodiment Schematic diagram of vertical and horizontal lattice structure of signal line group of signal line layer and signal line group of scanning line layer Flow chart of the outline of the digital photoconductor drum manufacturing process Process schematic diagram of the manufacturing process (1) Process schematic diagram of the manufacturing process (2) Process schematic diagram of the manufacturing process (Part 3) Process schematic diagram of the manufacturing process (4) Process schematic diagram of the manufacturing process (part 5) Process schematic diagram of the manufacturing process (Part 6) Block diagram of digital photoconductor drum drive circuit Digital photoconductor drum drive timing chart Data transfer block diagram Explanatory drawing concerning detection of rotational phase of digital photosensitive drum (part 1) Explanatory drawing about detection of rotational phase of digital photosensitive drum (part 2) Explanatory drawing about detection of rotational phase of digital photosensitive drum (part 3) Top view of digital photoconductor drum

Explanation of symbols

A..Electrophotographic image forming apparatus 2..Digital photosensitive drum 33..Encoder wheel part 34..Phase detector 40..Cylinder base 50..Self-emitting device part 51..Signal line (First electrode line) / scanning line (second electrode line) control unit (control circuit unit), 52... Signal line layer, 52 e... Signal line (first electrode line), 53. 54..Scanning line layer, 54a..Scanning line, 60..Function separation part, 61..Insulating layer (transparent insulating / gas barrier layer), 62..Transparent conductive layer, 70..Photosensitive part

Claims (10)

A cylindrical substrate;
A self-luminous device portion provided on the cylindrical base, and extending in a ring shape in the circumferential direction of the cylindrical base and separated by an insulator in the longitudinal direction of the cylindrical base. A second electrode line including a first electrode line layer including a first electrode line and a plurality of second electrode lines extending in a longitudinal direction of the cylindrical base and separated and arranged by an insulator in a circumferential direction of the cylindrical base; A self-luminous device unit comprising an electrode line layer and an EL light emitting layer, wherein the first electrode line layer, the EL light emitting layer, and the second electrode line layer are laminated in this order on the cylindrical substrate;
A functional separation unit comprising a transparent insulating layer provided on the self-luminous device unit, and a transparent conductive layer provided on the transparent insulating layer;
A photoreceptor provided on the transparent conductive layer;
The electrophotographic photosensitive drum is characterized in that the first electrode wire is provided in an annular shape without a seam.   The self-luminous device unit includes a control unit that controls a voltage between the first electrode line and the second electrode line, and includes the first electrode line layer on the control unit. The electrophotographic photosensitive drum according to claim 1.   The electrophotographic photosensitive drum according to claim 1, wherein the second electrode line is formed of a transparent conductive oxide. An electrophotographic image forming apparatus comprising: a charging device that charges a rotatable electrophotographic photosensitive drum; and a developing device that develops a latent image formed on the electrophotographic photosensitive drum with a developer.
The electrophotographic photosensitive drum is:
A cylindrical substrate;
A self-luminous device portion provided on the cylindrical base, and extending in a ring shape in the circumferential direction of the cylindrical base and separated by an insulator in the longitudinal direction of the cylindrical base. A second electrode line including a first electrode line layer including a first electrode line and a plurality of second electrode lines extending in a longitudinal direction of the cylindrical base and separated and arranged by an insulator in a circumferential direction of the cylindrical base; A self-luminous device unit comprising an electrode line layer and an EL light emitting layer, wherein the first electrode line layer, the EL light emitting layer, and the second electrode line layer are laminated in this order on the cylindrical substrate;
A functional separation unit comprising a transparent insulating layer provided on the self-luminous device unit, and a transparent conductive layer provided on the insulating layer;
A photoreceptor provided on the transparent conductive layer;
An electrophotographic image forming apparatus, wherein the first electrode line is provided in an annular shape without a seam.   5. The electron according to claim 4, wherein the self-luminous device unit includes a control unit for the first electrode line and the second electrode line, and includes the first electrode line layer on the control unit. Photo image forming apparatus.   6. The electrophotographic image forming apparatus according to claim 4, wherein the second electrode line is made of a transparent conductive oxide. In the method for producing an electrophotographic photosensitive drum,
A first electrode line layer including a plurality of first electrode lines extending in a ring shape in the circumferential direction of the cylindrical substrate and separated by an insulator in the longitudinal direction of the cylindrical substrate on the cylindrical substrate; A second electrode line layer including a plurality of second electrode lines extending in the longitudinal direction of the cylindrical substrate and separated and arranged by an insulator in the circumferential direction of the cylindrical substrate, and an EL light emitting layer. A step of forming a self-luminous device part, the step of laminating the first electrode line layer, the EL light emitting layer, and the second electrode line layer in this order on the cylindrical substrate;
Forming a functional separation unit comprising a transparent insulating layer and a transparent conductive layer on the self-luminous device part, wherein the transparent insulating layer and the transparent conductive layer are arranged in this order after the self-luminous device part is formed; And forming with
Forming a photoconductor portion on the function separating portion, and forming the photoconductor portion after forming the transparent conductive layer;
And the first electrode wire is provided in an annular shape without a seam by processing a cylindrical member from the outer periphery.   The method for manufacturing an electrophotographic photosensitive drum according to claim 7, wherein the first electrode line layer is formed by a photolithography process.   The said self-light-emitting device part is provided with the control part of the said 1st electrode line and the said 2nd electrode line, and after providing the said control part, forms the said 1st electrode line layer, It is characterized by the above-mentioned. 9. A method for producing an electrophotographic photosensitive drum according to 8.   The method of manufacturing an electrophotographic photosensitive drum according to claim 7, wherein the second electrode line is formed of a transparent conductive oxide.