JP2015116750A - Image formation device and image formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device of longer life, without sacrificing durability of a light emitting element, relating to an image formation device in which light emission quantity of the light emitting element is changed by changing a current according to magnitude of gradation data.SOLUTION: A latent image is formed on a surface of a photoreceptor drum 102 by making an organic EL panel 101 turn on for a short time at a wanted position and a timing, in addition to irradiation of a first light emitting element 109. The first light emitting element 109, during a period of a recording command, continues to irradiate the photoreceptor drum 102 with the light of light quantity for charging a voltage on a surface of the photoreceptor drum 102 up to a voltage around a level at which toner does not stick.

Description

  The present invention relates to an image forming apparatus having a light emitter for raising the surface potential of a photosensitive drum surface to a predetermined voltage in addition to a light emitting element for forming a latent image in a line head using a light emitter, and The present invention relates to an image forming method.

  2. Description of the Related Art Conventionally, an image forming apparatus that writes a latent image on an image carrier uses an organic EL element or LED as a writing unit. However, the fixed exposure device using organic EL elements and LEDs is more difficult to control the luminance than the conventional exposure device that reflects a semiconductor laser with a polygon mirror and draws a latent image on the image carrier. It was difficult to express.

JP 2003-341141 A

  Therefore, Patent Document 1 discloses an image forming apparatus that changes the amount of light emitted from a light emitting element by changing a current in accordance with the size of gradation data. However, in the exposure method of Patent Document 1, the durability of the light emitting element is sacrificed in order to increase the amount of current flowing through the light emitting element and increase the amount of light.

  Accordingly, an object of the present invention is to provide an image forming apparatus and an image forming method having a long lifetime without sacrificing durability of a light emitting element.

  For this reason, the image forming apparatus of the present invention irradiates the surface of the image carrier with an image carrier on which a latent image is formed by irradiating with a predetermined amount of light so that the irradiated position is charged to a predetermined potential. A first light emitting means having a possible light source, a second light emitting means having a light source different from the first light emitting means capable of irradiating the surface of the image carrier, and a latent image on the surface of the image carrier. And a control unit that charges the position irradiated by overlapping the irradiation from the second light emitting unit to the predetermined potential at the position irradiated from the first light emitting unit during the forming operation. It is characterized by that.

  According to the present invention, the first light emitting element irradiates the light of the amount of light that charges the surface of the photosensitive drum to a voltage at which the toner does not adhere, and the second light emitting element irradiates the surface of the photosensitive drum. Thus, an image forming apparatus having a long life can be realized without sacrificing durability of the light emitting element.

(A), (b) is the figure which showed the light emitting element, respectively. (A) is the figure which showed the light emitting element, (b) is the figure which showed the recording medium. 2 is a cross-sectional view schematically showing a transfer portion of an electrophotographic apparatus using an image forming apparatus. FIG. It is a cross-sectional schematic diagram of the exposure apparatus which integrated the 2nd light emitting element and the 1st light emitting element. (A), (b) is the figure which showed the 2nd light emitting element and the 1st light emitting element. 2 is a cross-sectional view schematically showing a transfer portion of an electrophotographic apparatus using an image forming apparatus. FIG.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic view of an organic EL panel 101 for forming a latent image on the surface of a photoconductor in the present embodiment when viewed from the front. In the organic EL panel 101, a plurality of organic EL elements L (light emitting element arrays) arranged in the main scanning direction (X direction) are arranged in the sub scanning direction (Y direction).

  FIG.1 (b) is the schematic diagram which looked at the 1st light emitting element 109 which has the 2nd surface emitting element M in this embodiment from the front. The first light emitting element 109 is provided on the surface of the organic EL panel 101 that does not face the photoconductor, and toner does not adhere to the voltage on the surface of the photoconductive drum (image carrier) 102 via the organic EL panel 101. Irradiate light with a light amount that charges to a certain voltage.

  FIG. 2A is a diagram showing the organic EL element L1-1 that is lit in black and the organic EL element L1-2 that is not lit in white when the image P1 shown in FIG. 2B is formed. .

  FIG. 3 is a cross-sectional view schematically showing a transfer portion of an electrophotographic apparatus using an image forming apparatus (hereinafter also referred to as a printer) in the present embodiment.

  FIG. 4 is a schematic cross-sectional view of an exposure apparatus in which the second light emitting element 101 and the first light emitting element 109 are integrated in the present embodiment. The second light emitting element 101 includes a transparent positive electrode L101, a hole transport layer L102, a light emitting layer L103, an electron transport layer L104, and a transparent negative electrode L105. The first light emitting element 109 includes a transparent positive electrode M101, a hole transport layer M102, a light emitting layer M103, an electron transport layer M104, a transparent negative electrode M105, a reflecting plate M106, and a transparent insulating layer M107.

  A PC (not shown) converts the light emission data for each page in the main scanning direction, and converts the light emission data in units of one pixel in the main scanning direction. Sent to the printer. When one page of recording data is transmitted from the PC, the printer rotates the photosensitive drum 102, which is a rotating body, substantially parallel to the sub-scanning direction Y of the organic EL panel 101. As shown in FIG. 3, the image forming apparatus of the present embodiment develops toner on the organic EL panel 101, the photosensitive drum 102 having the photosensitive layer formed on the surface, and the latent image portion charged to a predetermined potential of the photosensitive drum. A developing unit 103 and a transfer roller 104 that contacts the photosensitive drum are provided. Further, the image forming apparatus includes a cleaning blade 105 that collects toner remaining on the photosensitive drum 102 after transfer, a waste toner box 106 that stores the collected toner, and a C roller (charging roller) that uniformly charges the surface of the photosensitive drum 102. 107). Further, the image forming apparatus irradiates the photoconductor with an optical system lens array 108 between the organic EL panel 101 and the photosensitive drum 102 and a light amount of light for charging the surface voltage of the photoconductor to a voltage at which toner does not adhere. An exposure unit 120 is provided. The sheet P is conveyed between the photosensitive drum 102 and the transfer roller 104 of such an image recording apparatus, and toner is transferred from the photosensitive drum, so that an image is formed on the surface of the sheet P.

  In the present embodiment, SLA12DG-1-33.4 manufactured by Nippon Sheet Glass Co., Ltd. is used as the optical system lens array 108, but the type of the optical system lens array is not limited to this, depending on design requirements. The photosensitive drum 102 rotates substantially parallel to the sub-scanning direction (Y direction) of the organic EL panel 101.

  A recording method in the image forming apparatus in the present embodiment will be specifically described. When recording a straight line image P1 having a width of one pixel in the sub-scanning direction as shown in FIG. 2B, the control unit (not shown) controls the main scanning row of the organic EL panel 101 as the second light emitting element. One organic EL element in each column of X1 to X17 is turned on. The lighting timing in the sub-scanning direction (arrow Y direction) varies depending on the rotational speed of the photosensitive drum 102. When the rotation direction S of the photosensitive drum 102 is directed from the scan row Y1 to Y6, the lighting timing of the scan row Y2 is later than the scan row Y1 by the distance from the scan row Y1 to the scan row Y2, and the scan row Y3 is scanned. Lights later than Y1 by the distance from scan row Y1 to scan row Y3.

  Further, the first light emitting element 109 continues to irradiate the photosensitive drum 102 with a light amount of light that charges the surface voltage of the photosensitive drum 102 to a voltage at which toner does not adhere, while there is a recording command. At this time, the first light emitting element 109 irradiates light on the portion of the photosensitive drum 102 where the toner is attached and the portion around the portion where the toner is attached. In this way, the first light emitting element 109 irradiates the light of the amount of light that charges the voltage on the surface of the photosensitive drum 102 to a voltage at which the toner does not adhere (below the threshold). As a result, the voltage on the surface of the photosensitive drum 102 can be charged to a voltage capable of attaching toner (above a threshold value) simply by lighting the organic EL element of the second light emitting element for a short time at a portion where the toner is attached. That is, the organic EL element of the second light emitting element is not turned on at the portion where the toner on the surface of the photosensitive drum 102 is not attached (latent image non-forming operation). After forming (carrying) a latent image on the surface of the photosensitive drum 102 by the organic EL panel 101 and the first light emitting element 109, toner is attached to the latent image from the developing unit 103, and further image forming operation thereafter The toner adhering to the latent image portion is transferred onto the recording paper P. Further, the toner is melted by heat and pressure at a fixing unit (not shown) to fix the toner on the recording paper P, thereby completing the recording.

  In this embodiment, the first light emitting element 109 is provided on the side opposite to the side facing the photosensitive drum 102 of the organic EL panel 101. However, the positional relationship between the organic EL panel 101 and the first light emitting element 109 is as follows. , Either may be in a position facing the photosensitive drum 102. That is, the organic EL panel 101 may be provided on the back surface of the first light emitting element 109.

  In the present embodiment, the first light emitting element 109 includes the surface light emitting element M, but a plurality of organic EL elements such as the organic EL panel 101 may be arranged.

  Thus, in addition to the irradiation of the first light emitting element 109, the organic EL panel 101 is lit for a short time at a desired position and timing, thereby forming a latent image on the surface of the photosensitive drum 102. As a result, an image forming apparatus having a long lifetime of the second light emitting element can be realized.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  FIGS. 5A and 5B are views showing the second light emitting element 101 and the first light emitting element in the present embodiment. In the present embodiment, a case where an LED and a cold cathode tube are used for the first light emitting element will be described.

  B101 in FIG. 5A is an LED that is a first light emitting element, and while there is a recording command, the photosensitive drum 102 emits light of a light amount that charges the surface voltage of the photosensitive drum 102 to a voltage at which toner does not adhere. Irradiation is possible.

  C101 in FIG. 5B is a cold cathode tube which is the first light emitting element, and the light of the amount of light that charges the surface voltage of the photosensitive drum 102 to a voltage at which the toner does not adhere while the recording command is issued. 102 can be irradiated.

  Thus, in addition to irradiating the first light emitting element using an LED or a cold cathode tube, the organic EL panel 101 is lit for a short time at a desired position and timing, so that a latent image is formed on the surface of the photosensitive drum 102. Form. As a result, an image forming apparatus having a long lifetime of the second light emitting element can be realized.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the present embodiment is the same as that of the first embodiment, only the characteristic configuration will be described below.

  FIG. 6 is a cross-sectional view schematically showing a transfer portion of an electrophotographic apparatus using the image forming apparatus of this embodiment.

  In the present embodiment, the first light emitting element 209 is provided on the upstream side in the rotation direction S of the photosensitive drum 202 of the second light emitting element 201 with respect to the first embodiment. When a recording command is sent by a control unit (not shown), the first light emitting element 209 is turned on, and the photosensitive drum 202 is irradiated with light having a light amount that charges the surface voltage of the photosensitive drum 202 to a voltage that does not cause toner adhesion. Irradiate. Thereafter, the second light emitting element 201 is turned on at a desired position and timing for a short time, thereby drawing a latent image on the surface of the photosensitive drum 202 and causing the developing machine 203 to attach toner to the latent image. Then, the image is transferred onto the recording paper P on the transfer roller 204, and the toner is melted by heat and pressure at a fixing unit (not shown) to fix the toner on the recording paper P, thereby completing the recording.

  In this way, in addition to providing the first light emitting element 209 upstream of the rotation direction S of the photosensitive drum 202 of the second light emitting element 201 and irradiating it, the second light emitting element 201 is lit for a short time at a desired position and timing. As a result, a latent image is formed on the surface of the photosensitive drum 202. As a result, an image forming apparatus having a long lifetime of the second light emitting element can be realized.

101 Second light emitting device (organic EL panel)
DESCRIPTION OF SYMBOLS 102 Photosensitive drum 103 Developing unit 107 C roller 108 Optical system lens array 109 1st light emitting element 201 2nd light emitting element 202 Photosensitive drum 203 Developing machine 204 Transfer roller 209 1st light emitting element P Recording paper

Claims (7)

By irradiating with a predetermined amount of light, the irradiation position is charged to a predetermined potential and an image carrier on which a latent image is formed;
First light emitting means having a light emitting source capable of irradiating the surface of the image carrier;
A second light emitting means capable of irradiating the surface of the image carrier and having a light emission source different from the first light emitting means;
In the latent image forming operation on the surface of the image carrier, the position irradiated by overlapping the irradiation from the second light emitting unit on the position irradiated from the first light emitting unit is the predetermined potential. And an image forming apparatus comprising: a control unit configured to charge the battery.   2. The second light emitting means includes a plurality of light emitting element arrays arranged in a rotation axis direction of the image carrier, which is a rotating body, arranged in a rotation direction of the image carrier. Image forming apparatus.   The first light emitting means is provided integrally with the second light emitting means on the opposite side of the second light emitting means to the side facing the image carrier, and carries the latent image of the image carrier. The image forming apparatus according to claim 1, wherein the portion and its periphery are irradiated.   The image carrier is a rotator, and the first light emitting unit is provided upstream of the second light emitter in the rotation direction of the image carrier. The image forming apparatus according to claim 2.   5. The image forming apparatus according to claim 1, wherein the light emitting light source of the first light emitting unit is an organic EL panel.   6. The image forming apparatus according to claim 1, wherein the light emitting light source of the second light emitting means is an LED or a cold cathode tube. By irradiating with a predetermined amount of light, the irradiation position is charged to a predetermined potential, and a latent image forming step for forming a latent image on the image carrier;
A first light emitting step having a light emitting source for irradiating the surface of the image carrier;
A second light emitting step having a light emitting source different from the first light emitting means capable of irradiating the surface of the image carrier;
During the latent image forming operation on the surface of the image carrier, the position irradiated by overlapping the irradiation in the second light emitting step to the position irradiated in the first light emitting step is set to the predetermined potential. An image forming method comprising: a control step of charging.

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