JP2006224316A - Light-emitting panel and image printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multicolor electrophotographic image printer with a small number of light-emitting panels for writing an electrostatic latent image. <P>SOLUTION: The light-emitting panel 10 of the image printer, where the plurality of light-emitting elements 14A and 14B with light-emitting characteristics changed by imparted electric energy are arranged, can emit beams, which constitute images different from each other, from both sides. The beam, which is emitted from one side of the light-emitting panel 10, is applied to each of surfaces of two (e. g. photo-conductor drums 110Y and 110M) of photo-conductor drums 110Y, 110M, 110C and 110K, so that the electrostatic latent image can be formed on the surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting panel capable of emitting light on both sides and an electrophotographic image printing apparatus that preferably uses the light emitting panel.

  In recent years, a light-emitting panel including a light-emitting element such as an EL element (electroluminescence element) on a substrate has been developed. Such a light emitting panel is not only used as a display device, but also, for example, as disclosed in Patent Document 1 and Patent Document 2, an image carrier (for example, a photosensitive drum) of an electrophotographic image printing apparatus. It is also used to write an electrostatic latent image on the screen.

  By the way, as a display device, a light emitting panel capable of emitting light on both sides has been developed. For example, Patent Documents 3 to 5 disclose light-emitting panels that can display different images on both sides. Each of these light emitting panels has a common cathode layer provided at the center, a pair of light emitting layers provided on both sides of the common cathode layer, and a pair of individual anode layers provided outside the light emitting layer. Accordingly, light emitting portions are provided on both sides of the common cathode layer.

JP 2004-195676 A Japanese Patent Application Laid-Open No. 2004-195677 Japanese Patent Application Laid-Open No. 5-109483 JP 2000-58260 A JP 2002-304961 A

  Conventionally, only an image printing apparatus for writing an electrostatic latent image on only one image carrier with one light emitting panel has been proposed. Therefore, in a full-color image printing apparatus, four light-emitting panels are required to obtain a latent image corresponding to four colors of cyan, magenta, blue, and black. In a two-color image printing apparatus, two light emitting panels are required.

  On the other hand, a light-emitting panel in which light-emitting portions are provided on both sides of a common cathode layer has a large number of layers, and thus has many manufacturing processes.

  Accordingly, the present invention provides a multicolor electrophotographic image printing apparatus with a small number of light emitting panels for writing an electrostatic latent image, and a light emitting panel with few manufacturing processes that can be used for this. .

  A light-emitting panel according to the present invention is a light-emitting panel in which a plurality of light-emitting elements whose light-emission characteristics are changed by applied electric energy are arranged and can emit light beams constituting different images from both sides, A first region capable of emitting a light beam from the other surface and a second region capable of emitting a light beam from the other surface, wherein each of the light emitting elements includes a first electrode layer and a second electrode. A light-emitting layer that emits light according to a voltage between the first electrode layer and the second electrode layer, the light-emitting element in the first region; One electrode layer, the light emitting layer, and the second electrode layer are in the same plane as the first electrode layer, the light emitting layer, and the second electrode layer of the light emitting element in the second region, respectively. And the first electrode layer in the first region is The first electrode layer in the second region is formed from the same transparent material, and the light emitting layer in the first region is formed from the same material as the light emitting layer in the second region, and the first region A reflective layer for reflecting light from the light emitting layer is disposed on the light emitting layer side of the light emitting layer in the second region, and the second electrode layer in the second region is formed of a transparent material, In the second region, a reflective layer made of a light reflective material is disposed on the opposite side of the light emitting layer across the first electrode layer.

In the light emitting panel, in the first region, a reflective layer that reflects light from the light emitting layer is disposed on the second electrode layer side of the light emitting layer, and the first electrode layer is formed of a transparent material. Therefore, light from the light emitting layer is emitted to the outside through the first electrode layer. On the other hand, in the second region, the second electrode layer is formed of a transparent material, and the reflective layer is disposed on the opposite side of the light emitting layer across the first electrode layer. Is released to the outside through the second electrode layer. Accordingly, light is emitted from both sides of the light emitting panel.
Since the first electrode layers in the first region and the second region are in the same plane and are formed of the same transparent material, they can be formed of the same material almost simultaneously. In addition, since the light emitting layers in the first region and the second region are in the same plane and are formed of the same material, they can be formed of the same material almost simultaneously. Therefore, there are few manufacturing processes.

  In the light emitting panel, the second electrode layer in the first region may be formed of a light reflecting material, and may function as the reflecting layer in the first region. In this configuration, in the first region, the second electrode layer also serves as a reflective layer, so that it is possible to suppress an increase in the number of layers and thus the thickness of the panel.

  As another aspect, the second electrode layer in the first region is common to the second electrode layer in the second region, and is formed of a transparent material, and the second region is formed in the first region. The reflective layer formed of a light reflective material may be disposed on the opposite side of the light emitting layer with the second electrode layer interposed therebetween. In this configuration, the second electrode layer in the first region is the same as the second electrode layer in the second region, so that it is not necessary to pattern the second electrode layer in both regions. .

  An image printing apparatus according to the present invention includes a light emitting panel in which a plurality of light emitting elements whose light emission characteristics are changed by applied electric energy are arranged, and capable of emitting light beams constituting different images from both sides, and the light emission At least two image carriers on which latent images are formed by irradiating each surface with a light beam emitted from one side of the panel; and by attaching toner to the latent images, A developing unit that forms a visible image on the surface; and a transfer unit that transfers the visible image from the image carrier to another object. Here, the “image carrier” is typically a photosensitive drum, but may be a photosensitive belt having an endless belt shape.

  In this image printing apparatus, since a light emitting panel capable of emitting light on both sides is used for writing an electrostatic latent image on two image carriers, multicolor printing is possible, but the number of light emitting panels is small. .

  The light-emitting panel of the image printing apparatus is preferably any one of the light-emitting panels according to the present invention.

  In addition, the image printing apparatus is disposed between an intermediate transfer member to which the visible image is transferred from at least two of the image carriers by the transfer device, and between the one of the image carriers and the light-emitting panel. It is preferable to include a mirror that reflects a light beam emitted from one side of the panel and irradiates one of the image carriers. The “intermediate transfer member” is typically an intermediate transfer belt having an endless belt shape, but may be an intermediate transfer drum. In an image printing apparatus of a type that temporarily transfers a visible image from two image carriers to an intermediate transfer member, a developer for forming a visible image on each of the image carriers is provided downstream of the electrostatic latent image writing position and in the middle. It should be placed upstream of the transfer position of the visible image onto the transfer body. Accordingly, each image carrier should have a wide space for disposing the developing device downstream of the electrostatic latent image writing position and upstream of the visible image transfer position to the intermediate transfer body. However, when an electrostatic latent image is written on two image carriers using a light-emitting panel that can emit light on both sides, the space from the electrostatic latent image writing position to the visible image transfer position is narrow for one image carrier. Thus, there is a possibility that the developing device cannot be arranged. By providing a mirror that reflects the light beam emitted from one side of the light-emitting panel capable of emitting light on both sides and irradiates it on one side of the image carrier, the electrostatic latent image writing position on the image carrier is changed to the visible image transfer position. It is easy to secure a wide space and provide a developing device there.

  As another aspect, the image printing apparatus includes an intermediate transfer belt to which the visible image is transferred from at least two image carriers by the transfer device, and the visible image from one of the image carriers to the intermediate transfer belt. So that the angle of the intermediate transfer belt at the position where the image is transferred and the angle of the intermediate transfer belt at the position where the visible image is transferred from the other of the image carriers to the intermediate transfer belt, It is preferable to provide a belt direction controller that contacts the intermediate transfer belt. When an electrostatic latent image is written on two image carriers using a light-emitting panel that can emit light on both sides, the space from the electrostatic latent image writing position to the visible image transfer position becomes narrower on one image carrier. There is a possibility that the developing device cannot be arranged. By changing the angle of the intermediate transfer belt at the visible image transfer position for one of the image carriers with the angle of the intermediate transfer belt at the visible image transfer position for the other of the image carriers, It is easy to secure a wide space from the electrostatic latent image writing position to the visible image transfer position for the image carrier and to provide a developing device there.

  As yet another aspect, the image printing apparatus holds and conveys a sheet, and is arranged so that the visible image is transferred from at least two image carriers to the conveyed sheet by the transfer device. And a mirror disposed between one of the image carriers and the light-emitting panel, which reflects a light beam emitted from one side of the light-emitting panel and irradiates one of the image carriers. It is preferable to provide. The “sheet conveyance body” is typically a sheet conveyance belt having an endless belt shape, but may be a sheet conveyance drum. Also in this case, an electrostatic latent image writing position for the image carrier is provided by providing a mirror that reflects the light beam emitted from one side of the light-emitting panel capable of emitting light on both sides and irradiates one of the image carriers. It is easy to secure a wide space from the position to the visible image transfer position and provide a developing device there.

  As another aspect, a sheet conveying belt arranged to hold and convey a sheet, and to transfer the visible image from at least two image carriers onto the conveyed sheet by the transfer unit; An angle of the sheet conveyance belt at a position where the visible image is transferred from one of the image carriers to the sheet on the sheet conveyance belt, and the sheet on the sheet conveyance belt from the other of the image carriers. It is preferable that a belt direction controller that contacts the sheet conveying belt is provided so that the angle of the sheet conveying belt at the position where the visible image is transferred to the sheet conveying belt. By changing the angle of the sheet conveying belt at the visible image transfer position for one of the image carriers with the angle of the sheet conveying belt at the visible image transfer position for the other of the image carriers, It is easy to secure a wide space from the electrostatic latent image writing position to the visible image transfer position for the image carrier and to provide a developing device there.

  Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. In these drawings, the ratio of dimensions of each part is appropriately changed from the actual one.

<Light-emitting panel>
FIG. 1 is a cross-sectional view showing a light emitting panel 10 according to an embodiment of the present invention. FIG. 2 is a plan view of the electro-optical device. More specifically, FIG. 1 is a cross-sectional view taken along line AA in FIG.

  The light-emitting panel 10 illustrated in the figure is a line type for writing latent images on two image carriers (for example, a photosensitive drum 110 as shown in FIG. 4) in a multicolor image printing apparatus using an electrophotographic system. Used as an optical head. In the light emitting panel 10, a plurality of light emitting elements 14 </ b> A and 14 </ b> B whose light emission characteristics are changed by applied electric energy are arranged on the same plane. The light emitting panel 10 emits light beams constituting different images from both sides, so that a first region 12A that can emit light beams from the upper surface in FIG. 1 and a second region 12B that can emit light beams from the lower surface in FIG. Is provided.

  In this embodiment, the light emitting element is an organic light emitting diode (hereinafter referred to as “OLED”) element, and each light emitting element emits light according to an applied voltage. The light emitting panel 10 includes a flat substrate 18. The substrate 18 is made of a suitable transparent material such as glass or plastic. A driving element layer 20 is formed on the substrate 18, and a large number of light emitting elements 14A and 14B are formed thereon.

  Each of the array of light emitting elements 14A in the first region 12A and the array of light emitting elements 14B in the second region 12B is arranged in two rows and a zigzag pattern, as shown in FIG. The arrangement pattern of the light emitting elements is not limited to the illustrated form, and may be a single row or three or more rows, or may be arranged in another appropriate pattern.

  Although detailed illustration of the inside of the drive element layer 20 is omitted, a plurality of TFT (thin film transistor) elements and lines for supplying current to the TFT elements are provided here. Each TFT element applies a driving voltage to the light emitting element.

  In the first region 12A, the light emitted from each light emitting element 14A travels downward in FIG. 1 toward the substrate 18 side. That is, the first region 12A is equivalent to a bottom emission type OLED light emitting panel. On the other hand, in the second region 12B, the light emitted from each light emitting element 14B travels upward in FIG. That is, the second region 12B is equivalent to a top emission type OLED light emitting panel. However, as will be described below, most of the components of the regions 12A and 12B are common.

  Each of the light emitting elements 14A and 14B includes an anode layer (first electrode layer) 22 formed on the drive element layer 20, a hole injection layer 24 formed on the anode layer 22, and a top thereof. The light emitting layer 26 is formed, and the cathode layer (second electrode layer) 28A or 28B is formed thereon. The hole injection layer 24 and the light emitting layer 26 are formed in a recess defined by the insulating layer 30 and the partition wall 32.

The anode layer 22, the hole injection layer 24, the light emitting layer 26, and the cathode layer 28A of the light emitting element 14A in the first region 12A are the anode layer 22, the hole injection layer 24, and the light emitting layer of the light emitting element 14B in the second region 12B. Layer 26 and cathode layer 28A are each in the same plane. Further, the insulating layer 30 in the first region 12A and the insulating layer 30 in the second region 12B are common, and the partition 32 in the first region 12A and the partition 32 in the second region 12B are in the same plane and are the same. Formed from material. The material of the insulating layer 30 is, for example, SiO ₂ , and the material of the partition wall 32 is, for example, polyimide or acrylic.

  The anode layer 22 in the first region 12A is formed of the same transparent material as the anode layer 22 in the second region 12B, for example, ITO (Indium Tin Oxide). The hole injection layer 24 in the first region 12A is formed of the same material as the hole injection layer 24 in the second region 12B. The light emitting layer 26 in the first region 12A is also formed of the same material as the light emitting layer 26 in the second region 12B.

  In the first region 12A, in order to emit light emitted from the light emitting layer 26 of each light emitting element 14A downward, a reflective layer that reflects light from the light emitting layer 26 is provided on the cathode layer 28A side of the light emitting layer 26. Provided. In this embodiment, the cathode layer 28A in the first region 12A is formed of a conductive material having good light reflection characteristics such as aluminum, platinum, or silver, and functions as a reflective layer in the first region 12A. . The cathode layer 28A is common to the plurality of light emitting elements 14A in the first region 12A.

  On the other hand, in the second region 12B, the cathode layer 28A is formed of a transparent material, for example, ITO, in order to emit light emitted from the light emitting layer 26 of each light emitting element 14B upward. The cathode layer 28B is common to the plurality of light emitting elements 14B in the second region 12B. The cathode layers 28A and 28B may or may not be in contact with each other as shown. In the second region 12B, on the opposite side of the light emitting layer 26 across the anode layer 22, a reflective layer 33 made of a conductive material having good light reflection characteristics such as aluminum, platinum, or silver is disposed. Has been. The reflective layer 33 is on the uppermost layer of the drive element layer 20 and is in contact with the anode layer 22 in the second region 12B.

  The configuration of each light-emitting element in this embodiment is as described above. However, as a variation of the light-emitting element that can be used in the present invention, a type in which an electron injection layer is provided between the cathode layer and the light-emitting layer, or an appropriate one can be used. It may be a type having other layers such as a type in which an insulating layer is provided at a position.

  A sealing body 36 is bonded to the cathode layers 28A and 28B by a transparent adhesive 34. As the adhesive 34, for example, a transparent epoxy ultraviolet curable plastic, a transparent acrylic ultraviolet curable plastic, or various transparent thermosetting plastics can be used. The adhesive 34 preferably has a refractive index equivalent to or similar to that of the sealing body 36.

  The sealing body 36 seals the light emitting elements 14A and 14B in cooperation with the substrate 18 on which the light emitting elements 14A and 14B are formed. That is, the sealing body 36 cooperates with the substrate 18 to isolate the light emitting elements 14A and 14B from the outside air, particularly moisture and oxygen, and suppress their deterioration. The sealing body 36 is made of a suitable transparent material such as glass or plastic.

  In the light emitting panel 10, in the first region 12A, a reflective layer (cathode layer 28A) that reflects light from the light emitting layer 26 is disposed on the cathode layer 28A side of the light emitting layer 26, and the anode layer 22 is transparent. Since it is made of a material, light from the light emitting layer 26 is emitted to the outside through the anode layer 22. On the other hand, in the second region 12B, the cathode layer 28B is formed of a transparent material, and the reflective layer 33 is disposed on the opposite side of the light emitting layer 26 with the anode layer 22 interposed therebetween. Is emitted to the outside through the cathode layer 28B. Accordingly, light is emitted from both sides of the light emitting panel 10.

  In the light emitting panel 10, since many components in the regions 12A and 12B are common, the number of manufacturing steps can be reduced. For example, since the anode layers 22 in the regions 12A and 12B are in the same plane and are formed of the same transparent material, they can be formed of the same material almost simultaneously. Further, since the light emitting layers 26 in the regions 12A and 12B are in the same plane and are formed of the same material, they can be formed of the same material almost simultaneously.

  Further, in the light emitting panel 10, in the first region 12A, the cathode layer 28A also serves as a reflection layer that reflects light from the light emitting layer 16 downward. Therefore, it is possible to suppress an increase in the number of layers and thus the thickness of the panel.

  FIG. 3 is a cross-sectional view illustrating a modification of the light emitting panel 10. 3 may also be regarded as a cross-sectional view taken along line AA in FIG. In FIG. 3, the same reference numerals are used to indicate the same components as those described above, and these components will not be described in detail below.

  In this modification, a common cathode layer (second electrode layer) 28C is provided in the first region 12A and the second region 12B. That is, the cathode layer 28C is formed on all the light emitting layers 26 in the regions 12A and 12B. The cathode layer 28C is made of a transparent material such as ITO.

  On the opposite side of the light emitting layer 26 across the cathode layer 28C in the first region 12A, a reflective layer 38 made of a conductive material having good light reflection characteristics such as aluminum, platinum or silver is disposed. . The reflective layer 38 is in contact with the cathode layer 28C in the first region 12A. A sealing body 36 is bonded to the reflective layer 38 in the first region 12A and the cathode layer 28C in the second region 12B by a transparent adhesive 34.

  In this modified example, in the first region 12A, a reflective layer 38 that reflects light from the light emitting layer 26 is disposed on the cathode layer 28A side of the light emitting layer 26, and the anode layer 22 is formed of a transparent material. Therefore, the light from the light emitting layer 26 is emitted to the outside through the anode layer 22. On the other hand, in the second region 12B, the cathode layer 28B is formed of a transparent material, and the reflective layer 33 is disposed on the opposite side of the light emitting layer 26 with the anode layer 22 interposed therebetween. Is emitted to the outside through the cathode layer 28B. Accordingly, light is emitted from both sides of the light emitting panel 10.

  In this configuration, since the cathode layer 28C in the first region 12A is common to the cathode layer 28C in the second region 12B, the labor for patterning the cathode layer is not required as compared with the embodiment of FIG.

<Image printing device>
FIG. 4 is a schematic view showing a usage state of the light-emitting panel 10. As shown in the figure, the light emitting panel 10 is used for writing an electrostatic latent image on two image carriers (for example, a photosensitive drum 110 as shown in FIG. 4) in a multicolor image printing apparatus using an electrophotographic system. Used as a line-type optical head. Examples of the image printing apparatus include a printer, a printing part of a copying machine, and a printing part of a facsimile. In FIG. 4, the electrostatic latent image is written on the lower photosensitive drum 110 by the light emitting element 14A in the first area 12A, and the electrostatic latent image is written on the upper photosensitive drum 110 by the light emitting element 14B in the first area 12B. Write an image.

  A converging lens array 40 is disposed at an intermediate point between the photosensitive drum 110 and the light emitting panel 10. Light from the light emitting element 14 </ b> A or 14 </ b> B of the light emitting panel 10 passes through the plurality of gradient index lenses 42 of the converging lens array 40 and reaches the photosensitive drum 110. The converging lens array 40 includes a plurality of gradient index lenses 42. Each of the gradient index lenses 42 is a graded index optical fiber formed such that the refractive index at the central axis, that is, the optical axis is low, and the refractive index increases as the distance from the central axis increases. The erecting image with respect to the image on the light emitting panel 10 can be formed on the photosensitive drum 110 by transmitting the light to be transmitted. The images obtained by the plurality of gradient index lenses 42 constitute one continuous image on the photosensitive drum 110. A specific example of the converging lens array 40 is SLA (Selfoc Lens Array) available from Nippon Sheet Glass Co., Ltd. (Selfoc \ SELFOC is a registered trademark of Nippon Sheet Glass Co., Ltd.).

  In the illustrated gradient index lens 40, the gradient index lenses 42 are arranged in a two-row zigzag pattern, and are fixed to the housing of the converging lens array 40 indicated by phantom lines in FIG. ing. However, the arrangement pattern of the gradient index lenses 42 is not limited to the illustrated form, and may be a single row or three or more rows, or may be arranged in another appropriate pattern.

  FIG. 5 is a schematic cross-sectional view showing an example of an image printing apparatus using the light emitting panel 10 of FIG. 1 or 3 as a line type optical head. This image printing apparatus is a tandem type full-color image printing apparatus using a belt intermediate transfer body system. This image printing apparatus is provided with a driving roller 121 and a driven roller 122. An endless intermediate transfer belt (intermediate transfer member) 120 is wound around these rollers 121 and 122 in the direction indicated by the arrow. The periphery of the rollers 121 and 122 is rotated. Although not shown, tension applying means such as a tension roller that applies tension to the intermediate transfer belt 120 may be provided.

  Around the intermediate transfer belt 120, four photosensitive drums 110Y, 110M, 110C, and 110K having the same size are arranged at predetermined intervals. The subscripts Y, M, C, and K mean that they are used to form yellow, magenta, cyan, and black visible images, respectively. The photosensitive drums 110Y, 110M, 110C, and 110K are rotationally driven in the direction indicated by the arrow in synchronization with the driving of the intermediate transfer belt 120. The outer peripheral surfaces of the rotating photosensitive drums 110Y, 110M, 110C, and 110K are uniformly charged by a corona charger 112 dedicated to the drum.

  The two photosensitive drums 110Y and 110M are exposed by one light emitting panel 10 as an exposure head, that is, a latent image writing head, and the other two photosensitive drums 110C and 110K are exposed by the other light emitting panel 10. . In this manner, an electrostatic latent image is written on the outer peripheral surface of the photosensitive drum charged by the corona charger 112. The light emitting panel 10 is installed such that its longitudinal direction is parallel to the bus line direction (main scanning direction) of the photosensitive drum 110. However, the light emitting panel 10 is inclined with respect to a line connecting the centers of the two photosensitive drums on which the latent image is written.

  The light beam emitted from the right surface of the light-emitting panel 10 in the upper part of the drawing passes through the right focusing lens array 40 and then directly irradiates the outer peripheral surface of the photosensitive drum 110Y, so that a latent image corresponding to a yellow visible image is obtained. Write. On the other hand, the light beam emitted from the left surface of the light-emitting panel 10 passes through the left focusing lens array 40 and is then reflected by the mirror 46, and then irradiates the outer peripheral surface of the photosensitive drum 110M. Write the latent image corresponding to the image.

  On the other hand, the light beam emitted from the left surface of the light emitting panel 10 at the lower side of the figure passes through the left focusing lens array 40 and then directly irradiates the outer peripheral surface of the photoconductive drum 110C to correspond to a cyan visible image. Write the latent image. On the other hand, the light beam emitted from the right surface of the light emitting panel 10 is transmitted through the right converging lens array 40 and then reflected by the mirror 46, and then irradiates the outer peripheral surface of the photosensitive drum 110K to produce black light. Write the latent image corresponding to the image.

  These mirrors 46 extend in parallel to the generatrix direction of the photosensitive drum. The light emitting panel 10 and the mirror 46 are arranged so that the light beam emitted from the light emitting panel 10 travels substantially along the normal line of the photosensitive drum and reaches the photosensitive drum for any photosensitive drum. Yes.

  In addition, toner as a developer is supplied to the outer peripheral surface of each of the rotating photosensitive drums 110Y, 110M, 110C, and 110K by a developing device 114 dedicated to the drum. A toner as a developer adheres to the electrostatic latent image, whereby a visible image, that is, a visible image is formed on the outer peripheral surface of the photosensitive drum.

  The yellow, magenta, cyan, and black developed images formed by the four-color single-color image forming station are sequentially transferred onto the intermediate transfer belt 120 to be superimposed on the intermediate transfer belt 120. As a result, a full-color visible image is obtained. Four primary transfer corotrons (transfer devices) 116 are arranged inside the intermediate transfer belt 120. The primary transfer corotron 116 is disposed in the vicinity of the photosensitive drum, and an intermediate transfer that passes between the photosensitive drum and the primary transfer corotron by electrostatically attracting a visible image from the adjacent photosensitive drum. The visible image is transferred to the belt 120.

  After the transfer of the visible image by the primary transfer corotron 116 and before charging by the charger 112, the outer peripheral surface of the photosensitive drum is cleaned by a cleaner (not shown) and further discharged by a corona discharger (not shown).

  Finally, the sheet 124 as an object on which an image is to be formed is conveyed by a conveyance roller (not shown), and is sent to a nip between the intermediate transfer belt 120 and the secondary transfer roller 126 that are in contact with the driving roller 121. The full color visible image on the intermediate transfer belt 120 is secondarily transferred to the sheet 124 by the secondary transfer roller 126 at once. Thereafter, the toner is fixed to the sheet 124 by a fixing device (not shown).

  In this image printing apparatus, since the light emitting panel 10 capable of emitting light on both sides is used for writing an electrostatic latent image on two photosensitive drums, the number of light emitting panels can be increased while multicolor printing is possible. Few.

  In an image printing apparatus of a type that temporarily transfers a visible image from two image carriers to an intermediate transfer member, a developer 114 that forms a visible image on each of the image carriers 110 is disposed downstream of the electrostatic latent image writing position. In addition, it should be arranged upstream of the position of the visible image transfer to the intermediate transfer body 120. Therefore, each image carrier 110 should have a wide space for disposing the developing device 114 downstream of the electrostatic latent image writing position and upstream of the visible image transfer position to the intermediate transfer body 120. However, when an electrostatic latent image is written on the two image carriers 110 with a light emitting panel capable of light emission on both sides, the space from the electrostatic latent image writing position to the visible image transfer position for one of the image carriers 110 is used. However, the developing device 114 may not be disposed. For example, if the light emitting panel 10 is simply arranged between the photosensitive drums 110Y and 110M on which the latent image is written, there is a possibility that a space for arranging the developing device 114 may not be obtained for one of the photosensitive drums 110M.

  On the other hand, in this embodiment, the light emitting panel 10 is tilted with respect to the line connecting the centers of the two photosensitive drums on which the latent image is written, and the light beam emitted from one side of the light emitting panel 10 is reflected by the mirror 46. The light is reflected and irradiated to the photosensitive drum 110M or 110K. Therefore, a wide space from the electrostatic latent image writing position to the visible image transfer position for the photosensitive drum 110M or 110K is secured, and the developing device 114 is easily provided there.

  FIG. 6 shows a modification of the image printing apparatus of FIG. In the form of FIG. 5, not only the tension side of the intermediate transfer belt 120 (the side where the belt runs from the driven roller 122 to the driving roller 121) but also the loose side of the intermediate transfer belt 120 (the belt from the driving roller 121 to the driven roller 122). Although the photosensitive drum is also disposed on the traveling side), in FIG. 6, the photosensitive drums 110Y, 110M, 110C, and 110K are disposed only on the tension side of the intermediate transfer belt 120.

Next, another embodiment of the image printing apparatus according to the present invention will be described.
FIG. 7 is a schematic cross-sectional view of another image printing apparatus using the light emitting panel 10 of FIG. 1 or 3 as a line type optical head. This image printing apparatus is a rotary development type full-color image printing apparatus using a belt intermediate transfer body system. In FIG. 7, the same reference numerals are used to denote components similar to those described above with reference to FIG. 5, and these components will not be described in detail below.

  In the image printing apparatus shown in FIG. 7, two photosensitive drums (image carriers) 110YC and 110MK are provided. These photosensitive drums are all arranged on the tension side of the intermediate transfer belt 120. The subscript YC means that it is used to form a yellow and cyan visible image, and the subscript MK means that it is used to form a magenta and black visible image.

  The photosensitive drums 110YC and 110MK are rotationally driven in the direction indicated by the arrow in synchronization with the driving of the intermediate transfer belt 120. The outer peripheral surfaces of the rotating photosensitive drums 110YC and 110MK are uniformly charged by a corona charger 112 dedicated to the drum.

  Further, the two photosensitive drums 110YC and 110MK are exposed by one light emitting panel 10 as an exposure head, that is, a latent image writing head. In this manner, an electrostatic latent image is written on the outer peripheral surface of the photosensitive drum charged by the corona charger 112. The light emitting panel 10 is installed such that its longitudinal direction is parallel to the bus line direction (main scanning direction) of the photosensitive drum 110. However, the light emitting panel 10 is inclined with respect to a line connecting the centers of the two photosensitive drums on which the latent image is written.

  The light beam emitted from the right surface of the light emitting panel 10 passes through the right converging lens array 40 and then directly irradiates the outer peripheral surface of the photosensitive drum 110YC. The light beam emitted from the right surface of the light-emitting panel 10 writes a latent image corresponding to a yellow visible image on the photosensitive drum 110YC in the first printing stage for one sheet in full-color printing, and cyan in the subsequent printing stage. A latent image corresponding to the visible image is written on the photosensitive drum 110YC.

  On the other hand, the light beam emitted from the left surface of the light-emitting panel 10 passes through the left focusing lens array 40, is reflected by the mirror 46, and then irradiates the outer peripheral surface of the photosensitive drum 110MK. The luminous flux emitted from the left surface of the light-emitting panel 10 writes a latent image corresponding to a magenta visible image on the photosensitive drum 110MK in the first printing stage for one sheet in full-color printing, and in the subsequent printing stage, the black image is black. A latent image corresponding to the visible image is written on the photosensitive drum 110MK.

  The mirror 46 extends in parallel to the generatrix direction of the photosensitive drum. The light emitting panel 10 and the mirror 46 are arranged so that the light beam emitted from the light emitting panel 10 travels substantially along the normal line of the photosensitive drum and reaches the photosensitive drum for any photosensitive drum. Yes.

  Further, toner as a developer is supplied to the outer peripheral surface of each of the rotating photosensitive drums 110YC and 110MK by a developing unit 50YC or 50MK dedicated to the drum. A toner as a developer adheres to the electrostatic latent image, whereby a visible image, that is, a visible image is formed on the outer peripheral surface of the photosensitive drum.

  The developing units 50YC and 50MK are rotary drums, and can be rotated about the rotation shaft 50A. The developing unit 50YC has two developing devices 52Y and 52C, and the developing unit 50MK has two developing devices 52M and 52K. The developing device 52Y supplies yellow toner to the photosensitive drum 110YC while it is close to the photosensitive drum 110YC. Conversely, while the developing device 52C is close to the photosensitive drum 110YC, the developing device 52C supplies cyan toner to the photosensitive drum 110YC. Similarly, the developing device 52M supplies magenta toner to the photosensitive drum 110MK while it is close to the photosensitive drum 110MK. On the contrary, while the developing device 52K is close to the photosensitive drum 110MK, the developing device 52K supplies black toner to the photosensitive drum 110MK.

  The yellow, magenta, cyan, and black visible images are sequentially transferred onto the intermediate transfer belt 120 by the electrostatic attraction action of the primary transfer corotron 116, thereby being superimposed on the intermediate transfer belt 120, resulting in full color. Is obtained. First, during the first rotation of the intermediate transfer belt 120 in full-color printing, a yellow visible image is formed on the outer peripheral surface of the photosensitive drum 110YC by the cooperative action of the light beam emitted from the right surface of the light emitting panel 10 and the developing device 52Y. This is formed and adsorbed onto the intermediate transfer belt 120. Further, during the first rotation of the intermediate transfer belt 120, a magenta visible image is formed on the outer peripheral surface of the photosensitive drum 110MK by the cooperative action of the light beam emitted from the left surface of the light emitting panel 10 and the developing device 52M. This is adsorbed onto the intermediate transfer belt 120. After the yellow and magenta visible images are formed on the photosensitive drum, the developing units 50YC and 50MK rotate halfway, and the developing devices 52C and 52K come close to the photosensitive drum.

  During the next rotation of the intermediate transfer belt 120, a cyan visible image is formed on the outer peripheral surface of the photosensitive drum 110 </ b> YC by the cooperative action of the light beam emitted from the right surface of the light emitting panel 10 and the developing device 52 </ b> C. Adsorbed on the intermediate transfer belt 120. Further, during the next rotation of the intermediate transfer belt 120, a black visible image is formed on the outer peripheral surface of the photosensitive drum 110MK by the cooperative action of the light beam emitted from the left surface of the light emitting panel 10 and the developing device 52K. This is adsorbed onto the intermediate transfer belt 120. After the cyan and black visible images are formed on the photosensitive drum, the developing units 50YC and 50MK rotate halfway, and the developing devices 52Y and 52M come close to the photosensitive drum.

  As described above, the full-color visible image superimposed on the intermediate transfer belt 120 is secondarily transferred collectively onto the sheet 124 by the secondary transfer roller 126. The toner is fixed to the sheet 124 by a fixing device (not shown).

  After the transfer of each visible image by the primary transfer corotron 116 and before charging by the charger 112, the outer peripheral surface of the photosensitive drum is cleaned by a cleaner (not shown), and is further discharged by a corona discharger (not shown).

  Also in this embodiment, the light emitting panel 10 is tilted with respect to the line connecting the centers of the two photosensitive drums on which the latent image is written, and the light beam emitted from one surface of the light emitting panel 10 is reflected by the mirror 46 to be photosensitive. The body drum 110MK is irradiated. Therefore, a wide space from the electrostatic latent image writing position to the visible image transfer position for the photosensitive drum 110MK is secured, and it is easy to provide the developing unit 50MK there.

Next, still another embodiment of the image printing apparatus according to the present invention will be described.
FIG. 8 is a schematic sectional view showing another image printing apparatus using the light emitting panel 10 of FIG. 1 or 3 as a line type optical head. This embodiment is a modification of the embodiment of FIG. In FIG. 8, the same reference numerals are used to indicate components similar to those described above with reference to FIG. 5, and these components will not be described in detail below.

  In the form of FIG. 8, the light-emitting panel 10 is positioned exactly in the middle of two photosensitive drums on which a latent image is written, and is disposed perpendicular to the line connecting the centers of these two photosensitive drums. ing. However, the track of the intermediate transfer belt 120 is changed to a concave shape by belt direction changing rollers (belt direction control bodies) 130 and 132. More precisely, the belt direction changing roller 130 contacts the inner peripheral surface of the intermediate transfer belt 120, and the belt direction changing roller 132 contacts the outer peripheral surface of the intermediate transfer belt 120, and the belt direction changing roller 130 and the driving roller The belt portion between 121 (or driven roller 122) is bent in a concave shape. The belt direction changing rollers 130 and 132 are tension rollers and can rotate independently, but rotate following the intermediate transfer belt 120 and running.

  In this way, the belt direction changing rollers 130 and 132 are configured so that the angle of the intermediate transfer belt 120 at the position where the visible image is transferred from the photosensitive drum 110Y (or 110C) to the intermediate transfer belt 120, and the photosensitive drum 110M ( Alternatively, the intermediate transfer belt 120 is brought into contact with the intermediate transfer belt 120 so that the angle of the intermediate transfer belt 120 at the position where the visible image is transferred from the intermediate transfer belt 120 to 110 K) is different.

  When an electrostatic latent image is written on two image carriers 110 with a light emitting panel capable of emitting light on both sides, the space from the electrostatic latent image writing position to the visible image transfer position is narrow for one image carrier 110. Therefore, the developing device 114 may not be arranged. For example, when the intermediate transfer belt 120 travels on the common tangent line of the driving roller 121 and the driven roller 122, if the light emitting panel 10 is simply disposed between the photosensitive drums 110Y and 110M on which the latent image is written, There is a possibility that a space for arranging the developing device 114 may not be obtained for the photosensitive drum 110M.

  In contrast, in this embodiment, the angle of the intermediate transfer belt 120 at the visible image transfer position with respect to the photosensitive drum 110M (or 110K) is changed by the belt direction changing rollers 130 and 132 to the photosensitive drum 110Y (or 110C). ) Is different from the angle of the intermediate transfer belt 120 at the visible image transfer position, thereby ensuring a wide space from the electrostatic latent image writing position to the visible image transfer position on the photosensitive drum 110M (or 110K). It is easy to provide the developing device 114 there.

  A belt direction control body that changes the trajectory of the intermediate transfer belt 120 is preferable because there is little risk of damage such as wear caused by the belt direction changing rollers 130 and 132 that rotate following the intermediate transfer belt 120 to the intermediate transfer belt 120. However, an object that is always stationary and on which the intermediate transfer belt 120 slides may be used as the belt direction controller.

  This embodiment is a modification of the embodiment shown in FIG. 5, but the embodiment shown in FIGS. 6 and 7 is also modified by providing a belt direction control body similar to this embodiment. May be.

Next, still another embodiment of the image printing apparatus according to the present invention will be described.
FIG. 9 is a schematic cross-sectional view showing another image printing apparatus using the light emitting panel 10 of FIG. 1 or 3 as a line type optical head. This embodiment is a modification of the embodiment of FIG. 9, the same reference numerals are used to indicate components similar to those described above in connection with FIG. 5, and these components will not be described in detail below.

  The image printing apparatus in the form of FIG. 9 is a tandem type full-color image printing apparatus in which a sheet conveying belt (sheet conveying member) 140 is provided instead of the intermediate transfer belt 120. On the sheet conveying belt 140, the sheet 124 is sucked and held by a guide and an electrostatic suction device (not shown). Further, the sheet 124 is peeled from the sheet conveying belt 140 by a peeling claw not shown.

  While being conveyed by the sheet conveying belt 140, a visible image is transferred to the sheet 124 from the photosensitive drums 110Y, 110M, 110C, and 110K by the primary transfer corotron 116. In this embodiment, the light emitting panel 10 is used, and one light emitting panel 10 writes latent images on two photosensitive drums. Further, the light emitting panel 10 is tilted with respect to a line connecting the centers of the two photosensitive drums on which the latent image is written, and the light beam emitted from one side of the light emitting panel 10 is reflected by the mirror 46 to be the photosensitive drum 110M or Irradiate to 110K. Therefore, a wide space from the electrostatic latent image writing position to the visible image transfer position for the photosensitive drum 110M or 110K is secured, and the developing device 114 is easily provided there.

Next, still another embodiment of the image printing apparatus according to the present invention will be described.
FIG. 10 is a schematic cross-sectional view showing another image printing apparatus using the light emitting panel 10 of FIG. 1 or 3 as a line type optical head. This embodiment is a modification of the embodiment of FIG. 10, the same reference numerals are used to indicate components similar to those described above in connection with FIG. 8, and these components will not be described in detail below.

  The image printing apparatus in the form of FIG. 10 is a tandem type full-color image printing apparatus in which a sheet conveying belt (sheet conveying member) 140 is provided instead of the intermediate transfer belt 120. On the sheet conveying belt 140, the sheet 124 is sucked and held by a guide and an electrostatic suction device (not shown). Further, the sheet 124 is peeled from the sheet conveying belt 140 by a peeling claw not shown.

  While being conveyed by the sheet conveying belt 140, a visible image is transferred to the sheet 124 from the photosensitive drums 110Y, 110M, 110C, and 110K by the primary transfer corotron 116. In this embodiment, the light emitting panel 10 is used, and one light emitting panel 10 writes latent images on two photosensitive drums.

  As in the embodiment of FIG. 8, in the embodiment of FIG. 10, the light-emitting panel 10 is positioned exactly between the two photosensitive drums on which the latent image is written, and connects the centers of these two photosensitive drums. Arranged perpendicular to the line. However, the track of the sheet conveying belt 140 is changed to a concave shape by belt direction changing rollers (belt direction control bodies) 130 and 132. More precisely, the belt direction changing roller 130 contacts the inner peripheral surface of the sheet conveying belt 140, and the belt direction changing roller 132 contacts the outer peripheral surface of the sheet conveying belt 140, and the belt direction changing roller 130 and the driving roller The belt portion between 121 (or driven roller 122) is bent in a concave shape.

  By the belt direction changing rollers 130 and 132, the angle of the sheet conveying belt 140 at the visible image transfer position for the photosensitive drum 110M (or 110K) is changed to the sheet conveyance at the visible image transfer position for the photosensitive drum 110Y (or 110C). By making the angle different from that of the belt 140, a wide space from the electrostatic latent image writing position to the visible image transfer position for the photosensitive drum 110M (or 110K) is secured, and the developing device 114 can be easily provided there. It is.

  The embodiment shown in FIGS. 9 and 10 is a modification of the embodiment shown in FIGS. 5 and 8. However, the embodiment shown in FIGS. Similarly to the embodiment, the intermediate transfer belt 120 may be replaced with the sheet conveying belt 140.

<Other variations>
In the above light-emitting panel, an OLED element is used as a light-emitting element that converts applied electrical energy into optical energy. However, even if another light-emitting element (for example, an inorganic EL element) is used in the light-emitting panel. Good.

  Each of the above image printing apparatuses is a full-color image printing apparatus using four color toners, but the above technique is applied to other multicolor image printing apparatuses such as an image printing apparatus using two color toners. Such applications are within the scope of the present invention.

  In the above image printing apparatus, the light emitting panel 10 of FIG. 1 or FIG. 3 is used as an exposure device for the photosensitive drum, but other light emitting panels capable of emitting light beams constituting different images from both sides are exposed. It may be used as an exposure device for a body drum, and such an application is within the scope of the present invention. For example, you may use the light emission panel of patent document 3-patent document 5. FIG.

It is sectional drawing which shows the light emission panel which concerns on embodiment of this invention. FIG. 2 is a plan view of the electro-optical device in FIG. 1. It is sectional drawing which shows the modification of the light emission panel which concerns on this invention. It is the schematic which shows the use condition of the light emission panel which concerns on this invention. It is a schematic sectional drawing which shows an example of the image printing apparatus using the light emission panel of FIG. 1 or FIG. It is a schematic sectional drawing which shows the modification of the image printing apparatus of FIG. It is a schematic sectional drawing which shows the other image printing apparatus using the light emission panel of FIG. 1 or FIG. It is a schematic sectional drawing which shows the other image printing apparatus using the light emission panel of FIG. 1 or FIG. It is a schematic sectional drawing which shows the other image printing apparatus using the light emission panel of FIG. 1 or FIG. It is a schematic sectional drawing which shows the other image printing apparatus using the light emission panel of FIG. 1 or FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light emitting panel, 12A ... 1st area | region, 12B ... 2nd area | region, 14A, 14B ... Light emitting element, 18 ... Board | substrate, 22 ... Anode layer (1st electrode layer), 24 ... Hole injection layer, 26 Light emitting layer, 28A, 28B, 28C ... Cathode layer (second electrode layer), 30 ... Insulating layer, 32 ... Partition, 33, 38 ... Reflective layer, 36 ... Sealed body, 50YC, 50MK ... Developing unit, 52Y , 52C,..., Development unit, 110, 110Y, 110M, 110C, 110K, 110YC, 110MK ... photosensitive drum (image carrier), 114 ... development unit, 116 ... primary transfer corotron (transfer unit), 120 ... intermediate transfer belt (Intermediate transfer member), 124... Sheet, 130, 132... Belt direction changing roller (belt direction control member), 140.

Claims (9)

A plurality of light emitting elements whose emission characteristics are changed by given electric energy are arranged, and are light emitting panels capable of emitting light beams constituting different images from both sides,
A first region capable of emitting a light beam from one surface, and a second region capable of emitting a light beam from the other surface;
Each of the light emitting elements includes a light emitting layer that is interposed between the first electrode layer and the second electrode layer and emits light in accordance with a voltage between the first electrode layer and the second electrode layer. Have
The first electrode layer, the light emitting layer, and the second electrode layer of the light emitting element in the first region are the first electrode layer, the light emitting layer, and the light emitting element in the second region, respectively. Each in the same plane as the second electrode layer,
The first electrode layer in the first region is formed of the same transparent material as the first electrode layer in the second region;
The light emitting layer in the first region is formed of the same material as the light emitting layer in the second region,
A reflective layer that reflects light from the light emitting layer is disposed on the second electrode layer side of the light emitting layer in the first region,
The second electrode layer in the second region is formed of a transparent material;
A light emitting panel, wherein a reflective layer made of a light reflective material is disposed on the opposite side of the light emitting layer across the first electrode layer in the second region.   2. The light-emitting panel according to claim 1, wherein the second electrode layer in the first region is formed of a light reflecting material and functions as the reflective layer in the first region. The second electrode layer in the first region is common to the second electrode layer in the second region, and is formed of a transparent material.
2. The light emitting panel according to claim 1, wherein the reflective layer formed of a light reflective material is disposed on the opposite side of the light emitting layer across the second electrode layer in the first region. . A plurality of light emitting elements whose light emission characteristics are changed by applied electric energy, and a light emitting panel capable of emitting light beams constituting different images from both sides;
At least two image carriers on which a latent image is formed on each surface by irradiating each surface with a light beam emitted from one side of the light emitting panel;
A developer that forms a visible image on the surface of the image carrier by attaching toner to the latent image;
An image printing apparatus comprising: a transfer unit that transfers the visible image from the image carrier to another object.   The image printing apparatus according to claim 4, wherein the light-emitting panel is the light-emitting panel according to claim 1. An intermediate transfer member to which the visible image is transferred by the transfer unit from at least two of the image carriers;
And a mirror disposed between one of the image carriers and the light-emitting panel, and reflecting a light beam emitted from one surface of the light-emitting panel to irradiate one of the image carriers. The image printing apparatus according to claim 4 or 5. An intermediate transfer belt to which the visible image is transferred from at least two of the image carriers by the transfer device;
The angle of the intermediate transfer belt at the position where the visible image is transferred from one of the image carriers to the intermediate transfer belt, and the position where the visible image is transferred from the other of the image carriers to the intermediate transfer belt 6. The image printing apparatus according to claim 4, further comprising a belt direction controller that contacts the intermediate transfer belt so as to make the angle of the intermediate transfer belt different from each other. A sheet conveying body arranged to transfer the visible image from at least two image carriers to the sheet being conveyed while holding and conveying the sheet;
And a mirror disposed between one of the image carriers and the light-emitting panel, and reflecting a light beam emitted from one surface of the light-emitting panel to irradiate one of the image carriers. The image printing apparatus according to claim 4 or 5. A sheet conveying belt disposed and arranged to transfer the visible image from at least two image carriers to the sheet being conveyed while holding and conveying the sheet;
The angle of the sheet conveying belt at a position where the visible image is transferred from one of the image carriers to the sheet on the sheet conveying belt, and from the other of the image carriers to the sheet on the sheet conveying belt. 6. The belt direction controller according to claim 4, further comprising a belt direction controller that contacts the sheet conveying belt so as to vary an angle of the sheet conveying belt at a position where the visible image is transferred. The image printing apparatus described.

Images