JP4582353B2 - Exposure head and tandem color image forming apparatus using the same - Google Patents

Description

The present invention relates to an exposure head and a tandem color image forming apparatus using the same, and more particularly to a sealing structure of the exposure head.

  Conventionally, in an image forming apparatus such as a copying machine, a printer, and a fax machine using electrophotography, a laser scanning optical system is generally used as an optical writing unit.

  Under such circumstances, Japanese Patent Application Laid-Open No. H10-228561 proposes a technique for positioning and mounting an EL array exposure head on an image carrier cartridge to improve the positioning accuracy of the EL array exposure head with respect to the image carrier.

Further, Patent Document 2 proposes a method for integrating organic EL light emitting elements on a single chip to eliminate variations in light emission characteristics and to reduce costs.
JP 2002-23593 A JP-A-11-138899

  By the way, when an organic EL array is used as the optical writing unit of the image forming apparatus, the light emitting unit and the driving unit can be configured on a single substrate, so that the element position accuracy is higher than the LED and the element width can be reduced. . However, the organic EL light emitting element has a problem that the element deteriorates due to the influence of ultraviolet rays, and the amount of emitted light and the light emission efficiency are lowered. In particular, when the organic EL array exposure head is attached to the image carrier cartridge, the organic EL array exposure head is moved out of the apparatus together with the image carrier cartridge or external light for the purpose of attaching and detaching the image carrier cartridge or jamming. Exposed to. At this time, there is a problem that the organic EL light emitting element is deteriorated by irradiating the organic EL light emitting material of the organic EL array exposure head with ultraviolet light from the fluorescent lamp or the sun. Such deterioration of the organic EL light emitting element causes a decrease in the light emission amount of the element and a variation in the light emission amount between the elements, thereby degrading image quality such as printing.

An object of the present invention is to provide a sealing structure of an exposure head that prevents deterioration of an organic EL light emitting element or the like.

The exposure head of the present invention that achieves the above object comprises a transparent substrate,
An organic EL light emitting unit located on one surface of the substrate;
A first cover that is disposed in a state of covering the opposite side of the light emitting side of the light emitting unit from the substrate side in a state where it is not in contact with the light emitting unit, and being bonded to the one surface of the substrate;
A second cover that covers the first cover and is arranged in a state where the first cover of the substrate is bonded to the same surface as the bonded surface;
With
Either the first cover or the second cover has a light shielding function.

In this case, it is desirable that the inner surface of the second cover and the outer surface of the first cover are not in contact with each other.

In the present invention, at least two or more image carriers and image forming stations are provided,
The image forming station includes:
The charging means arranged around the image carrier, the transparent substrate, the organic EL light emitting unit located on one surface of the substrate, and the substrate side which is the light emitting side of the light emitting unit in a state not in contact with the light emitting unit A first cover disposed in a state of covering the side and bonded to the one surface of the substrate, and covering the first cover and bonding on the same surface as the surface of the substrate to which the first cover is bonded A second cover arranged in a state in which the first cover or the second cover includes an exposure head having a light shielding function, a developing unit, and a transfer unit,
It includes a tandem color image forming apparatus that performs color image formation when a recording medium passes through each of the image forming stations.

In the present invention, the side opposite to the light emission side of the exposure head, particularly the side opposite to the light emission side, is configured as described above.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an exposure head of the present invention and a tandem color image forming apparatus using the same will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing the overall configuration of one embodiment of the image forming apparatus of the present invention. In this embodiment, an intermediate transfer belt is used as the transfer belt.

  In FIG. 1, an image forming apparatus 1 according to the present exemplary embodiment is mounted on a housing body 2, a first opening / closing member 3 that can be opened and closed on the front surface of the housing body 2, and on an upper surface of the housing body 2. The first opening / closing member 3 also has an opening / closing lid 3 ′ attached to the front surface of the housing body 2 so as to be openable and closable. The opening / closing lid 3 ′ can be opened and closed in conjunction with or independently of the first opening / closing member 3.

  In the housing body 2, an electrical component box 5 containing a power circuit board and a control circuit board, an image forming unit 6, a blower fan 7, a transfer belt unit 9, and a paper feed unit 10 are disposed, and a first opening / closing member In FIG. 3, a secondary transfer unit 11, a fixing unit 12, and a recording medium conveying means 13 are arranged. The consumables in the image forming unit 6 and the paper feeding unit 10 are configured to be detachable from the main body. In this case, the configuration including the transfer belt unit 9 can be removed and repaired or replaced. It has become.

  A first opening / closing member 3 is mounted on the housing body 2 so as to be openable and closable on both sides of the lower front surface of the housing body 2 via a rotating shaft 3b.

  In this embodiment, as will be described later, each unit can be attached and detached by accessing only from the front surface of the apparatus, so that the apparatus can be installed in a room in a compact manner.

  In FIG. 1, a transfer belt unit 9 includes a drive roller 14 disposed below the housing body 2 and driven to rotate by a drive source (not shown), a driven roller 15 disposed obliquely above the drive roller 14, An intermediate transfer belt 16 that is stretched between two rollers 14 and 15 and is driven to circulate in the direction of the arrow shown in the figure, and a cleaning means 17 that comes into contact with and separates from the surface of the intermediate transfer belt 16. The intermediate transfer belt 16 is disposed in a direction inclined to the left in the drawing with respect to the drive roller 14. As a result, the belt surface 16a with the belt conveyance direction downward when the intermediate transfer belt 16 is driven is positioned below. In the present embodiment, the belt surface 16a is a belt tension surface (surface pulled by the drive roller 14) when the belt is driven.

  The driving roller 14 and the driven roller 15 are rotatably supported by the support frame 9a, and a rotating portion 9b is formed at the lower end of the supporting frame 9a. The rotating portion 9b is a rotation provided on the housing body 2. The support frame 9a is fitted to the housing body 2 so as to be rotatable. A lock lever 9c is rotatably provided at the upper end of the support frame 9a, and the lock lever 9c can be locked to a locking shaft 2c provided in the housing body 2.

  The drive roller 14 also serves as a backup roller for the secondary transfer roller 19 constituting the secondary transfer unit 11. The driven roller 15 is also used as a backup roller for the cleaning means 17. The cleaning means 17 is provided on the belt surface 16a side facing down in the transport direction.

  A primary transfer member 21 made of a leaf spring electrode is opposed to an image carrier 20 of each of the image forming stations Y, M, C, and K, which will be described later, on the back surface of the belt surface 16a facing downward in the conveyance direction of the intermediate transfer belt 16. The transfer force is applied to the primary transfer member 21 by contact with the elastic force.

  A test pattern sensor 18 is installed on the support frame 9 a of the transfer belt unit 9 in the vicinity of the drive roller 14. This test pattern sensor 18 is a sensor for positioning each color toner image on the intermediate transfer belt 16, detecting the density of each color toner image, and correcting the color shift and image density of each color image. The image forming unit 6 includes a plurality (four in this embodiment) of image forming stations Y (for yellow), M (for magenta), C (for cyan), and K (for black) that form images of different colors. Each of the image forming stations Y, M, C, and K includes an image carrier 20 formed of a photosensitive drum, and a charging unit 22, an image writing unit 23, and a developer disposed around the image carrier 20. Means 24 are provided. Note that the charging unit 22, the image writing unit 23, and the developing unit 24 give the figure numbers only to the image forming station Y, and the other image forming stations have the same configuration, and thus the drawing numbers are omitted. Further, the arrangement order of the image forming stations Y, M, C, and K is arbitrary.

  Then, the image carrier 20 of each image forming station Y, M, C, K is brought into contact with the belt surface 16a facing downward in the transport direction of the intermediate transfer belt 16, and as a result, each image forming station Y, M , C and K are also arranged in a direction inclined to the left in the drawing with respect to the drive roller 14. The image carrier 20 is rotationally driven in the conveyance direction of the intermediate transfer belt 16 as indicated by the arrows in the figure.

  The charging means 22 is composed of a conductive brush roller connected to a high voltage generation source, and the outer periphery of the brush is opposite to the image bearing member 20 as a photosensitive member at a peripheral speed of 2 to 3 times. The surface of the image carrier 20 is uniformly charged by contact rotation. Further, when such a conductive brush roller is used in an image forming apparatus having a cleaner-less configuration as in this embodiment, a bias having the same polarity as the toner charging polarity is applied to the brush roller during non-image formation. Thus, the transfer residual toner adhering to the brush roller is discharged to the image carrier 20, transferred onto the intermediate transfer belt 16 at the primary transfer portion, and collected by the cleaning means 17 of the intermediate transfer belt 16. .

  By using such a charging means 22, the surface of the image carrier can be charged with an extremely small current, so that the inside and outside of the apparatus is not contaminated with a large amount of ozone unlike the corona charging method. In addition, since the contact with the image carrier 20 is soft, it is difficult for the transfer residual toner generated when the roller charging method is used to adhere to the charging roller, and stable image quality and device reliability are ensured. can do.

  As will be described later, the image writing unit 23 uses an organic EL array exposure head in which organic EL light emitting elements are arranged in a line in the axial direction of the image carrier 20. The organic EL array exposure head has an advantage that the optical path length is shorter than that of the laser scanning optical system, is compact, can be disposed close to the image carrier 20, and the entire apparatus can be downsized. In this embodiment, the image carrier 20, the charging unit 22 and the image writing unit 23 of each of the image forming stations Y, M, C and K are unitized as one image carrier unit 25 and supported together with the transfer belt unit 9. By making the frame 9a replaceable, the organic EL array exposure head is positioned relative to the image carrier 20, and when the image carrier unit 25 is replaced, the organic EL array exposure head is also replaced.

  Next, details of the developing unit 24 will be described on behalf of the image forming station K. In the present embodiment, the image stations Y, M, C, and K are disposed in an oblique direction, and the image carrier 20 is in contact with the belt surface 16a facing downward in the conveyance direction of the intermediate transfer belt 16. The toner storage container 26 is disposed obliquely downward. Therefore, a special configuration is adopted as the developing unit 24.

  That is, the developing unit 24 includes a toner storage container 26 that stores toner (hatched part in the drawing), a toner storage part 27 formed in the toner storage container 26, and a toner disposed in the toner storage part 27. The stirring member 29, the partition member 30 partitioned on the upper part of the toner storage portion 27, the toner supply roller 31 disposed above the partition member 30, and the toner supply roller 31 provided on the partition member 30 The developing roller 33 disposed so as to contact the toner supply roller 31 and the image carrier 20, and the regulation blade 34 contacting the developing roller 33.

  The image carrier 20 is rotated in the conveyance direction of the intermediate transfer belt 16, and the developing roller 33 and the supply roller 31 are rotationally driven in a direction opposite to the rotation direction of the image carrier 20, as shown by the arrows in the figure. The stirring member 29 is driven to rotate in the direction opposite to the direction of rotation of the supply roller 31. The toner stirred and carried up by the stirring member 29 in the toner storage unit 27 is supplied to the toner supply roller 31 along the upper surface of the partition member 30, and the supplied toner is rubbed against the blade 32 and slid on the supply roller 31. The toner is supplied to the surface of the developing roller 33 by a mechanical adhesion force to the surface uneven portion and an adhesion force by frictional band power. The toner supplied to the developing roller 33 is regulated to a predetermined thickness by the regulating blade 34, and the thinned toner layer is conveyed to the image carrier 20 so that the developing roller 33 and the image carrier 20 come into contact with each other. The latent image portion of the image carrier 20 is developed at the nip portion configured as described above and in the vicinity thereof.

  In this embodiment, the developing roller 33 on the side facing the image carrier 20, the toner supply roller 31, and the contact portion between the developing roller 33 and the regulating blade 34 are not buried in the toner in the toner storage unit 27. With this configuration, it is possible to prevent fluctuations in the contact pressure of the regulating blade 34 against the developing roller 33 due to a decrease in the stored toner, and surplus toner scraped off from the developing roller 33 by the regulating blade 34 falls into the toner reservoir 27. Therefore, filming of the developing roller 33 can be prevented.

  Further, the contact portion between the developing roller 33 and the regulating blade 34 is positioned below the contact position between the supply roller 31 and the developing roller 33, and the surplus that has been supplied to the developing roller 33 by the supply roller 31 and has not shifted to the developing roller 33. A path is provided for returning the toner and excess toner regulated and removed from the developing roller 33 by the regulating blade 34 to the toner reservoir 27 below the developing means. The toner returning to the toner reservoir 27 is contained in the toner reservoir 27 by the stirring member 29. The toner is agitated and supplied again to the toner introduction portion near the supply roller 31 by the agitating member 29. Therefore, the excess toner is dropped to the lower portion without being jammed on the sliding portion of the supply roller 31 and the developing roller 33 or the contact portion of the developing roller 33 and the regulating blade 34, and the toner in the toner storing portion 27 is stirred. It is possible to prevent the toner in the developing unit from gradually deteriorating and a sudden change in image quality occurring immediately after the replacement of the developing unit.

  Further, the paper feed unit 10 includes a paper feed unit including a paper feed cassette 35 in which the recording media P are stacked and held, and a pickup roller 36 that feeds the recording media P from the paper feed cassette 35 one by one. Yes.

  In the first opening / closing member 3, a registration roller pair 37 that regulates the feeding timing of the recording medium P to the secondary transfer portion, and a secondary transfer unit that is pressed against the drive roller 14 and the intermediate transfer belt 16. A secondary transfer unit 11, a fixing unit 12, a recording medium conveyance unit 13, a paper discharge roller pair 39, and a duplex printing conveyance path 40 are provided.

  The fixing unit 12 includes a heating roller 45 that includes a heating element such as a halogen heater and is rotatable, a pressure roller 46 that presses and biases the heating roller 45, and is swingable on the pressure roller 46. The belt tension member 47, and the heat-resistant belt 49 stretched between the pressure roller 45 and the belt tension member 47, and the color image secondarily transferred to the recording medium are the heat roller 45 and the heat-resistant belt 49. The toner image is fixed on the recording medium at a predetermined temperature at the nip portion formed in step (b). In this embodiment, the fixing unit 12 can be disposed in a space formed obliquely above the intermediate transfer belt 16, in other words, in a space opposite to the image forming unit 6 with respect to the intermediate transfer belt 16. Thus, heat transfer to the electrical component box 5, the image forming unit 6, and the intermediate transfer belt 16 can be reduced, and the frequency of performing the color misregistration correction operation for each color can be reduced.

The outline of the operation of the entire image forming apparatus of the present embodiment as described above is as follows.
(1) When a print command signal (image formation signal) from a host computer (not shown) or the like (personal computer or the like) is input to the control circuit in the electrical component box 5, each image forming station Y, M, C, K The image carrier 20, the rollers of the developing unit 24, and the intermediate transfer belt 16 are driven to rotate.
(2) The surface of the image carrier 20 is uniformly charged by the charging means 22.
(3) The surface of the image carrier 20 that is uniformly charged in each of the image forming stations Y, M, C, and K is selectively exposed in accordance with the image information of each color by the image writing unit 23. Electrostatic latent image is formed.
(4) The electrostatic latent images formed on the respective image carriers 20 are developed with toner images by the developing means 24.
(5) A primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied to the primary transfer member 21 of the intermediate transfer belt 16, and the toner image formed on the image carrier 20 is transferred to the intermediate transfer belt 16 at the primary transfer portion. Are successively transferred onto the intermediate transfer belt 16 in accordance with the movement of.
(7) In synchronization with the movement of the intermediate transfer belt 16 on which the primary image has been primarily transferred, the recording medium P stored in the paper feed cassette 35 is fed to the secondary transfer roller 19 via the registration roller pair 37. .
(8) The primary transfer image is synchronized with the recording medium at the secondary transfer site and is pressed against the drive roller 14 of the intermediate transfer belt 16 by the pressing mechanism, and is opposite to the primary transfer image. The primary transfer image formed on the intermediate transfer belt 16 with a polarity bias applied is secondarily transferred to the recording medium fed synchronously.
(9) The transfer residual toner in the secondary transfer is conveyed in the direction of the driven roller 15 and scraped off by the cleaning means 17 disposed opposite to the roller 15, and the intermediate transfer belt 16 is refreshed. Again it is possible to repeat the above cycle.
(10) The toner image on the recording medium is fixed by passing the recording medium through the fixing unit 12, and then the recording medium is directed to a predetermined position (or the double-sided printing toward the paper discharge tray 4 if not double-sided printing). In this case, the sheet is conveyed toward the conveyance path 40 for double-sided printing.

  Next, replacement of consumables and jam processing will be described with reference to FIGS. In FIG. 2, the first opening / closing member 3 is rotated downward together with the opening / closing lid 3 ′ with the rotation shaft 3 b as a fulcrum to expose the fixing unit 12 and the secondary transfer unit 11, and the frame of the transfer belt unit 9. The lock lever 9c provided on the upper part of 9a is rotated to disengage the engagement shaft 2c, the frame 9a is rotated rightward with the rotation shaft 2b as a fulcrum, and the transfer supported by the frame 9a. The belt unit 9 and the image carrier unit 25 are exposed, and the developing means 24 supported on the housing body 2 side is also exposed by such an operation. In this state, as shown in FIG. The image carrier unit 25 and the transfer belt unit 9 can be removed from the frame 9a to be exchangeable, and the developing means 24 can be selectively exchanged independently. Furthermore, it is possible to jam the paper jammed in the conveyance path.

  Next, an image carrier unit (image carrier cartridge) according to an embodiment of the present invention in which the image carrier 20, the charging unit 22, and the image writing unit 23 of each of the image forming stations Y, M, C, and K are integrated. ) 25 will be described with reference to FIGS. FIG. 4 is a perspective view of the image carrier unit 25 viewed from the developing means 24 side, and FIG. 5 is a sectional view thereof. The image carrier unit 25 includes four images of image forming stations Y, M, C, and K that are spaced apart from each other in parallel in a case 50 made of an opaque metal plate or the like that is open on the side in contact with the intermediate transfer belt 16. A carrier (photosensitive drum) 20 is rotatably supported, and a conductive brush roller of the charging unit 22 is supported so as to rotate in contact with each image carrier 20 at a predetermined position. The image writing means 23 composed of an organic EL array exposure head is positioned on each image carrier 20 and supported in parallel to the downstream side of the image. An opening 51 for contacting the developing roller 33 of the developing unit 24 corresponding to each image carrier 20 is provided on the wall surface of the case 50 on the downstream side of the image writing unit 23. A shielding part 52 of the case 50 is left between each opening 51 and the image writing means 23, and a shielding part 53 of the case 50 is left between the charging means 22 and the image writing means 23. Yes. As will be described later, the shielding portions 52 and 53, particularly the shielding portion 52 between the opening 51 and the image writing means 23, emits ultraviolet rays from the outside to the light emitting portion made of the organic EL material in the image writing means 23. To prevent it from reaching.

  FIG. 6 shows a cross-sectional view of the image writing means 23. The image writing unit 23 includes a gradient index rod lens array 65 formed by stacking gradient index rod lenses 65 ′ (FIG. 8) in the center so as to face the image carrier 20 and to communicate inside and outside. An opaque housing 60 attached, an organic EL light emitting element array 61 attached facing the rear surface of the gradient index rod lens array 65 in the housing 60, and organic EL light emission therein from the rear surface of the housing 60 It comprises an opaque cover 66 that shields the element array 61, and the cover 66 is pressed against the back surface of the housing 60 by a fixed plate spring 67 so that the inside of the housing 60 is sealed in a light-tight manner.

FIG. 7 shows a cross-sectional view of an example of the vicinity of the light-emitting portion 63 of the organic EL light-emitting element array 61 of the image writing means 23 of FIG. 6, and the organic EL light-emitting element array 61 is made of, for example, 0.5 mm thick glass. On the substrate 62, TFTs (thin film transistors) 71 made of polysilicon having a thickness of 50 nm for controlling the light emission of the respective light emitting portions 63 are provided outside the margin corresponding to each of the two rows of light emitting portions 63 in a staggered arrangement, for example. An insulating film 72 made of SiO ₂ having a thickness of about 100 nm is formed on the glass substrate 62 except for the contact hole on the TFT 71, and is formed at the position of the light emitting portion 63 so as to be connected to the TFT 71 through the contact hole. An anode 73 made of 150 nm ITO is formed. Next, another insulating film 74 made of SiO ₂ having a thickness of about 120 nm is formed in a portion corresponding to a position other than the light emitting portion 63, and a hole 76 corresponding to the light emitting portion 63 is formed thereon, and the thickness is 2 μm. A bank 75 made of polyimide is provided, and a hole injection layer 77 having a thickness of 50 nm and a light emitting layer 78 having a thickness of 50 nm are formed in the hole 76 of the bank 75 in this order from the anode 73 side. A cathode first layer 79a made of Ca having a thickness of 100 nm and a cathode second layer 79b made of Al having a thickness of 200 nm are sequentially formed so as to cover the upper surface of 78, the inner surface of the hole 76, and the outer surface of the bank 75, A light emitting portion 63 of the organic EL light emitting element array 61 is formed by being covered with a cover glass 64 having a thickness of about 1 mm via an inert gas 80 such as nitrogen gas. Light emission from the light emitting unit 63 is performed on the glass substrate 62 side.

  As the material used for the light emitting layer 78 and the material used for the hole injection layer 77, for example, various materials known in Japanese Patent Laid-Open Nos. 10-12377 and 2000-323276 can be used, and details thereof are omitted.

  FIG. 8 shows an example of a mechanism for accurately positioning the image writing unit 23 with respect to each image carrier (photosensitive drum) 20 attached to the image carrier unit 25. The image carrier 20 is rotatably attached to the case 50 of the image carrier unit 25 on its axis, while the organic EL light emitting element array 61 is held in a long housing 60 as shown in FIG. Has been. Positioning pins 69 provided at both ends of the long housing 60 are fitted into opposing positioning holes of the case 50, and fixing screws are screwed into the screw holes of the case 50 through screw insertion holes 68 provided at both ends of the long housing 60. Each image writing means 23 is fixed at a predetermined position by screwing and fixing.

  Since it is configured as described above, for example, as shown in FIGS. 2 and 3, the developing means 24 is removed from the image carrier unit 25 to replace the consumables and jam processing so that the image carrier unit 25 is exposed to external light. , A fluorescent lamp and ultraviolet rays from the sun enter the case 50 from the opening 51 of the image carrier unit 25, but the shielding part 52 of the case 50 is left between the opening 51 and the image writing means 23. Therefore, the ultraviolet light directly enters the exposure position, is reflected by the image carrier 20 at that position, and emits light from the organic EL light emitting element array 61 in the image writing means 23 via the gradient index rod lens array 65. Reaching the part 63 is prevented. In addition, the ultraviolet rays incident from the opening of the case 50 on the side in contact with the intermediate transfer belt 16 are also shielded by the charging means 22 and the shielding portion 53 of the case 50 between the charging means 22 and the image writing means 23. Therefore, the ultraviolet rays are prevented from reaching the light emitting portion 63. In addition, when the inner surface of the case 50 is painted black that absorbs ultraviolet rays, the above-described ultraviolet shielding effect is more reliable.

  On the other hand, the housing 60 of the image writing means 23 is opaque, and the back surface thereof is covered with an opaque cover 66. Therefore, fluorescent light incident on the back surface of the organic EL light emitting element array 61 and ultraviolet rays from the sun are also organic. Reaching the light emitting part 63 of the EL light emitting element array 61 is prevented.

  Therefore, even if the image carrier unit 25 is exposed to ultraviolet rays for exchanging consumables or for jamming, the ultraviolet rays are not incident on the light emitting portion 63 of the organic EL light emitting element array 61 in the image writing unit 23 integrated therewith. The organic EL light emitting element is prevented from being deteriorated by ultraviolet rays.

  FIG. 9 is a cross-sectional view similar to FIG. 5 showing a modification of the embodiment of FIGS. 4 to 8. The difference from the embodiment of FIG. 5 is that the edge of each opening 51 on the image writing means 23 side. A shielding film 54 is arranged, and ultraviolet rays are emitted from the edge of the opening 51 on the image writing means 23 side and the image carrier 20 to the light emitting portion 63 of the organic EL light emitting element array 61 in the image writing means 23 by multiple reflection. It is the point which prevented it reaching | attaining completely, and the other structure is the same as that of the Example of FIGS.

  By the way, the image carrier unit 25 is provided with the shielding parts 52 and 53 on both sides of the image writing unit 23 as described above, and the back surface of the organic EL light emitting element array 61 is shielded by the opaque cover 66. The body unit 25 has a high sealing property, and when the gradient index rod lens array 65 covering the organic EL light emitting element array 61 from the front surface becomes dirty, the gradient index rod lens array 65 is removed from the image carrier unit 25. It is not easy to remove and clean.

  Therefore, it is desirable to provide a cleaning means for cleaning the tip of the gradient index rod lens array 65 without disassembling the image carrier unit 25. Examples thereof are shown in FIGS. FIG. 10 is a cross-sectional view of a portion of the image carrier unit 25 corresponding to one image carrier 20, FIG. 11 is a perspective view showing a cleaning member provided in that portion, and FIG. FIG. A cleaning member 81 as shown in FIG. 11 is disposed in the vicinity of the tip surface of the gradient index rod lens array 65 corresponding to each image forming station. The cleaning member 81 is a long plate member slightly longer than the length of the image carrier 20 in the longitudinal direction. A cleaning pad 82 is attached to the tip of the cleaning member 81, and a handle 84 is attached to the opposite end. A long opening 83 having a shape corresponding to the distal end surface of the gradient index rod lens array 65 is provided in the portion. The cleaning member 81 is slidable along the longitudinal direction at each position corresponding to the tip surface of the gradient index rod lens array 65 of each image writing unit 23 of the image carrier unit 25. When the cleaning member 81 is pulled out of the case 50 by gripping the handle 84, the cleaning pad 82 at the tip wipes the tip end surface of the gradient index rod lens array 65 from one end to the other end. Clean the surface. Then, when the cleaning member 81 is pushed back into the case 50 with the handle 84, the cleaning pad 82 again wipes the tip surface of the gradient index rod lens array 65 in the opposite direction, and the tip surface of the gradient index rod lens array 65. And the opening 83 of the cleaning member 81 covers the distal end surface of the gradient index rod lens array 65. Since exposure is performed in this state, the cleaning member 81 does not interfere with exposure.

  As a further modified example, a window member that cuts ultraviolet rays is fitted into the opening 83 of the cleaning member 81, the cleaning pad 82 is attached to the case 50, and the cleaning member 81 is pushed into the case 50. Thus, as shown in FIGS. 2 and 3, even if the image carrier unit 25 is exposed to external light for exchanging consumables or for jamming, the ultraviolet light incident from the opening 51 of the image carrier unit 25 is removed by this cleaning. Since the light is shielded by the window member in the opening 83 of the member 81, the ultraviolet rays reach the light emitting portion 63 of the organic EL light emitting element array 61 in the image writing means 23 through the gradient index rod lens array 65. Is prevented. In this case, the shielding portions 52 and 53 may be omitted, but the opaque housing 60 and the opaque cover 66 of the image writing means 23 are essential as in the embodiment of FIGS. .

  In this configuration, the cleaning member 81 is pulled out of the case 50 and pushed back again, so that the cleaning pad 82 attached to the case 50 side and the window member in the opening 83 are in sliding contact with each other. Can be cleaned.

  Furthermore, as another modification of the configuration of FIGS. 10 to 12, an ultraviolet cut film may be pasted on the tip surface of each gradient index rod lens array 65. By doing so, the ultraviolet light incident from the opening 51 of the image carrier unit 25 is shielded by this ultraviolet cut film, and therefore the organic EL light emitting element in the image writing means 23 via the gradient index rod lens array 65. The ultraviolet rays are prevented from reaching the light emitting portion 63 of the array 61. Also in this case, the shielding portions 52 and 53 may be omitted, but the opaque housing 60 and the opaque cover 66 of the image writing means 23 are essential as in the embodiment of FIGS. .

  As described above, the image carrier cartridge of the present invention and the image forming apparatus using the same have been described based on several embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible.

  As is apparent from the above description, according to the image carrier cartridge of the present invention and the image forming apparatus using the same, the exposure unit includes an organic EL light emitting element array and an imaging optical system disposed on the front surface thereof. Since the light shielding member for shielding at least ultraviolet rays is provided around the exposure means, the image carrier cartridge is removed from the image forming apparatus main body or exposed for exchanging consumables, jamming, etc. Even when UV light from a lamp or the sun comes into contact, the light shielding member prevents the UV light from reaching the light emitting part of the organic EL light emitting element array, and prevents the organic EL light emitting element from being deteriorated by the UV light. can do.

1 is a schematic cross-sectional view showing an overall configuration of an embodiment of an image forming apparatus of the present invention. FIG. 2 is a diagram illustrating a state in which a fixing unit, a secondary transfer unit, a transfer belt unit, an image carrier unit, and a developing unit are exposed in the apparatus of FIG. FIG. 3 is a diagram showing a state in which the image carrier unit and the transfer belt unit are removed and exchangeable in the state of FIG. 2. FIG. 2 is a perspective view of an image carrier unit used in the apparatus of FIG. 1 viewed from a developing unit side. FIG. 5 is a cross-sectional view of the image carrier unit in FIG. 4. FIG. 5 is a cross-sectional view of image writing means used in the image carrier unit of FIG. 4. It is sectional drawing of an example of the light emission part vicinity of the organic electroluminescent light emitting element array of the image writing means of FIG. It is a perspective view showing an example of a mechanism for accurately positioning an image writing unit with respect to each image carrier attached to the image carrier unit. FIG. 9 is a cross-sectional view similar to FIG. 5 showing a modification of the embodiment of FIGS. It is sectional drawing of the part corresponding to one image carrier of the image carrier unit of another modification. It is a perspective view which shows the cleaning member provided in the part of FIG. It is a perspective view similar to FIG. 4 of the modification of FIG.

Explanation of symbols

P ... recording medium, 1 ... image forming apparatus, 2 ... housing body, 2b ... rotating shaft (rotating fulcrum), 2c ... locking shaft, 3 ... first opening / closing member, 3 '... opening / closing lid, 3b ... times A moving shaft, 4 ... a second opening / closing member, 5 ... an electrical component box, 6 ... an image forming unit, 7 ... a blower fan, 9 ... a transfer belt unit, 9a ... a support frame, 9b ... a rotating part, 9c ... a lock lever, DESCRIPTION OF SYMBOLS 10 ... Paper feed unit, 11 ... Secondary transfer unit, 12 ... Fixing unit, 13 ... Recording medium conveyance means, 14 ... Drive roller, 15 ... Driven roller, 16 ... Intermediate transfer belt, 16a ... Belt at the time of intermediate transfer belt drive Belt surface with conveying direction facing downward, 17 ... cleaning means, 18 ... test pattern sensor, 19 ... secondary transfer roller, 20 ... image carrier, 21 ... primary transfer member, 22 ... charging means, 23 ... image writing means 24 ... Developer , 25 ... Image carrier unit (image carrier cartridge), 26 ... Toner reservoir, 27 ... Toner reservoir, 29 ... Toner stirring member, 30 ... Partition member, 31 ... Toner supply roller, 32 ... Blade, 33 ... Development Roller 34 ... Restricting blade 35 ... Paper cassette 36 ... Pickup roller 37 ... Registration roller pair 39 ... Discharge roller pair 40 ... Conveying path for double-sided printing 45 ... Heating roller 46 ... Pressure roller 47 ... belt tension member, 49 ... heat-resistant belt, 50 ... case, 51 ... opening, 52 ... shielding part, 53 ... shielding part, 54 ... shielding film, 60 ... housing, 61 ... organic EL light emitting element array, 62 ... glass Substrate, 63 ... Light emitting part, 64 ... Cover glass, 65 ... Refractive index distribution type rod lens array, 65 '... Refractive index distribution type rod lens, 66 ... Cover 67: Fixed leaf spring, 68: Screw insertion hole, 69: Positioning pin, 71: TFT (thin film transistor), 72 ... Insulating film, 73 ... Anode, 74 ... Insulating film, 75 ... Bank, 76 ... Bank hole, 77 ... Hole injection layer 78 ... Light emitting layer 79a ... Cathode first layer 79b ... Cathode second layer 80 ... Inert gas 81 ... Cleaning member 82 ... Cleaning pad 83 ... Opening 84 ... Handle

Claims (3)

A transparent substrate;
An organic EL light emitting unit located on one surface of the substrate;
A first cover that is disposed in a state of covering the opposite side of the light emitting side of the light emitting unit from the substrate side in a state where it is not in contact with the light emitting unit, and being bonded to the one surface of the substrate;
A second cover that covers the first cover and is arranged in a state where the first cover of the substrate is bonded to the same surface as the bonded surface;
Equipped with a,
Wherein either the first cover or the second cover, the exposure head according to claim Rukoto to have a light shielding function. 2. The exposure head according to claim 1, wherein the inner surface of the second cover and the outer surface of the first cover are arranged so as not to contact each other. Provide at least two image carriers and at least two image forming stations,
The image forming station includes:
The charging means arranged around the image carrier, the transparent substrate, the organic EL light emitting unit located on one surface of the substrate, and the substrate side which is the light emitting side of the light emitting unit in a state not in contact with the light emitting unit A first cover disposed in a state of covering the side and bonded to the one surface of the substrate, and covering the first cover and bonding on the same surface as the surface of the substrate to which the first cover is bonded is provided with a second cover disposed in a state, wherein either the first cover or the second cover, with the exposure head that having a light shielding function, a developing means and transfer means,
A tandem-type color image forming apparatus, wherein a color image is formed by a recording medium passing through each of the image forming stations.

Images