Image forming device

Abstract

To solve the problem that in cases when a door for maintenance, in an electrophotographic printer, is opened during exposure of a rotating photoconductor drum and the photoconductor drum is made to stop, a light-emitting element continues irradiating the same point on the surface of the halted photoconductor drum with light, accidentally forming a latent image, unless emission from the light-emitting element is halted when the photoconductor drum stops rotating.SOLUTION: It is possible to prevent a latent image from being accidentally formed on the surface of a photoconductor drum by outputting, to a light-emitting element drive unit 400, image data indicating that emission from a light-emitting element 602 be turned off, when a photoconductor drum 102 is halted.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that exposes a photosensitive drum to light to form a latent image on the surface of the photosensitive drum. [Background technology]

[0002] Conventionally, there has been known an image forming device that forms a latent image on the surface of a rotating photosensitive drum by exposing the photosensitive layer provided on the surface of the photosensitive drum with an exposure head that uses an OLED (organic light emitting diode) as a light source. The latent image is formed on the surface of the photosensitive drum when the charge on the surface of the photosensitive drum, which is charged to a predetermined potential, and the charge generated inside the photosensitive layer by exposure are neutralized, resulting in a change in the potential on the surface of the photosensitive drum. The image forming device develops the latent image formed on the surface of the photosensitive drum by attaching toner, and forms an image on the recording medium by transferring the developed toner image to the recording medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-87687 Summary of the Invention [Problem to be solved by the invention]

[0004] In an image forming apparatus, when a maintenance door exposing the interior of the image forming apparatus is opened during an image formation job in which an image is formed on a recording medium, the rotation of the photosensitive drum stops. For example, if the exposure head continues its exposure operation after the rotation of the photosensitive drum stops due to the opening of the maintenance door, the exposure head continues to expose the same point on the surface of the stopped photosensitive drum. As a result, charges generated in the photosensitive layer by the exposure accumulate inside the photosensitive layer. As a result, when the image formation job resumes due to the closing of the maintenance door and the surface of the photosensitive drum is charged, the charges accumulated inside the photosensitive layer neutralize the charges on the surface of the photosensitive drum due to the electrification. As a result, a latent image may be formed in a position not exposed by the exposure head, potentially resulting in an unintended image being formed on the recording medium.

[0005] In view of the above-mentioned problems, an object of the present invention is to suppress the formation of unintended latent images on the surface of a photosensitive drum in an image forming apparatus that forms an image on a recording medium. [Means for solving the problem]

[0006] The image forming apparatus according to the present invention comprises: In an image forming apparatus for forming an image on a recording medium, a photosensitive drum that rotates around a rotation axis; a charging means for charging the surface of the photosensitive drum to a predetermined potential; a plurality of light-emitting units arranged along the rotation axis of the photosensitive drum, the light-emitting units exposing a photosensitive layer provided on the photosensitive drum charged by the charging unit to form a latent image on the surface of the photosensitive drum; a maintenance door that can be opened to expose the inside of the image forming apparatus; a detection means for detecting the opening of the maintenance door; a generation unit that generates image data that controls turning on and off the light-emitting unit; a driver that drives the light-emitting unit based on the image data generated by the generator; a power source for supplying power to the drive unit; Equipped with the photosensitive drum stops rotating when the detection means detects that the maintenance door is open during an image forming job; the generation unit generates and outputs image data indicating that the light-emitting unit is to be turned off when the detection unit detects that the maintenance door is opened; When the maintenance door is opened, the supply of power from the power source to the drive unit is not interrupted. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, in an image forming apparatus that forms an image on a recording medium, it is possible to suppress the formation of an unintended latent image on the surface of a photosensitive drum. [Brief explanation of the drawings]

[0008] [Figure 1] Cross-sectional view of an image forming apparatus [Figure 2] External view of image forming apparatus [Figure 3] FIG. 1 is a diagram illustrating the positional relationship between a photosensitive drum and an exposure head. [Figure 4] Diagram explaining the structure of a printed circuit board [Figure 5] Image controller and printed circuit board block diagram [Figure 6] Emergency Shutdown Flowchart [Figure 7] Conceptual diagram of the light-off operation during image formation [Figure 8] Conceptual diagram of the light-off operation after image formation is completed [Figure 9] Block diagram of light-emitting element driver [Figure 10] Analog block diagram [Figure 11] Drive unit diagram DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment [Overall configuration of image forming device] The overall configuration of an image forming apparatus 10 according to a first embodiment will be described below with reference to the drawings. Note that the dimensions, materials, shapes, relative positions, etc. of the components described below do not limit the scope of the present invention unless otherwise specified.

[0010] FIG. 1 is a cross-sectional view of an image forming apparatus 10 according to a first embodiment. The image forming apparatus 10 comprises a scanner unit 100, an image creating unit 103, a fixing unit 104, a paper feed / transport unit 105, and a printer control unit 708 that controls these units.

[0011] The scanner unit 100 illuminates an original placed on a platen, optically reads the original image, and converts the image into an electrical signal to create image data.

[0012] In the image forming unit 103, a photosensitive drum 102 rotates around a rotation axis, and the photosensitive drum 102 is charged by a charger 107, which is a charging means.

[0013] The surface of the photosensitive drum 102 is charged to a predetermined potential by a charger 107 to which a predetermined voltage is applied, thereby causing discharge to occur on the surface of the photosensitive drum 102.

[0014] The surface of the photosensitive drum 102 may be charged to a predetermined potential by the charger 107 to which a predetermined voltage has been applied coming into contact with the surface of the photosensitive drum 102.

[0015] The exposure head 106 emits light in accordance with image data created by the scanner unit 100, and focuses the light emitted from the arrayed light emitting element group 201 onto the photosensitive drum 102, thereby exposing the surface of the photosensitive drum 102. The surface of the photosensitive drum is provided with a photoconductor including a photosensitive layer inside, and when the photosensitive layer is irradiated with light, an electric charge is generated. The electric charge generated in the photosensitive layer inside the photoconductor by exposure and the electric charge on the surface of the charged photosensitive drum 102 are neutralized, changing the electric potential on the surface of the photosensitive drum 102 and forming a latent image. That is, a latent image is formed on the surface of the photosensitive drum 102 by light emitted from a light-emitting element group 201 including a plurality of light-emitting elements 602.

[0016] The developing device 108 forms a toner image by attaching toner to the latent image formed on the photosensitive drum 102. The formed toner image is transferred onto paper transported on a transfer belt 111. In other words, the paper corresponds to the recording medium.

[0017] The image forming unit 103 has four image forming units that perform the above-mentioned series of electrophotographic processes (charging, exposing, developing, and transferring), and forms a full-color image by arranging the units in the order of cyan (C), magenta (M), yellow (Y), and black (K). After a predetermined time has elapsed since the start of image forming at the cyan station, the four image forming units sequentially perform image forming operations for magenta, yellow, and black.

[0018] In the paper feed / transport section 105, the paper is supplied by a pre-specified paper feed unit 109d among the internal paper feed units 109a and 109b, the external paper feed unit 109c, and the manual paper feed unit 109d, and the supplied paper is transported to the registration rollers 110.

[0019] Registration rollers 110 transport paper onto transfer belt 111 at the timing when the toner image formed in image creating unit 103 described above is transferred onto the paper. An optical sensor 113 is disposed opposite transfer belt 111. The optical sensor 113 detects the position of a test chart printed on transfer belt 111 to derive the amount of misalignment when each station transfers a toner image onto the paper. The amount of misalignment when each station transfers a toner image onto the paper thus derived is notified to image controller unit 700, which corrects the image position for each color. This control allows a full-color toner image to be transferred onto the paper without misalignment for each color.

[0020] The fixing unit 104 is composed of a combination of rollers and has a built-in heat source such as a halogen heater. It melts and fixes the toner on the paper onto which the toner image has been transferred from the transfer belt 111 using heat and pressure, and then discharges the paper outside the image forming device 10 using a paper discharge roller 112.

[0021] In the image forming apparatus 10, a series of operations from reading an image by the scanner unit 100 to ejecting the recording medium on which the image is formed to the outside of the image forming apparatus 10 is called an image forming job.

[0022] FIG. 2 is an external view of the image forming apparatus 10 according to this embodiment.

[0023] When a detection unit, which will be described later, detects that the maintenance door 104 is open during an image forming job, the printer control unit 708 outputs an emergency stop signal 704 and brings the image forming unit 103, the fixing unit 104, and the paper feed / transport unit 105 to an emergency stop. This emergency stop protects the internal components of the image forming apparatus 10 and ensures the safety of the user. Note that if the opening of the maintenance door 114 is detected during an image forming job and the image forming unit 103 stops, the rotation of the photosensitive drum 102 stops.

[0024] When the maintenance door 114 is opened, the inside of the image forming apparatus 10 is exposed. The inside of the image forming apparatus 10 that is exposed when the maintenance door 114 is opened includes, for example, the image forming unit 103, the fixing unit 104, and the paper feed / transport unit 105. When the maintenance door 114 is opened, the sensor 115 detects that the maintenance door 114 is open, and outputs the information that the sensor 115 has detected that the maintenance door 114 is open to the printer control unit 708. In other words, the sensor 115 corresponds to the detection means.

[0025] Another abnormality that may occur while the photosensitive drum 102 is being exposed is a paper jam in the paper transport path. A registration sensor arranged on a registration roller 110 in the paper transport path measures the time it takes for the leading and trailing edges of the paper to pass through the registration roller 110. The time it takes from when the leading edge of the paper passes through the registration roller 110 until the trailing edge of the paper passes through the registration roller 110 is compared with a predetermined threshold. If the time required for the passage is longer than the predetermined threshold, a paper jam is detected, and the detected paper jam is output to the printer control unit 708.

[0026] The occurrence of a paper jam may be detected not only by the registration roller 110 but also by the image forming unit 103, the fixing unit 104, the paper feed / transport unit 105, etc., as long as it is on the transport path of the recording medium.

[0027] [Configuration of exposure head 106] The exposure head 106 that exposes the photosensitive drum 102 will now be described.

[0028] 3(a) and 3(b) show the arrangement of the exposure head 106 relative to the photosensitive drum 102, and how light emitted from the light-emitting element group 201 is focused onto the photosensitive drum 102 by the rod lens array 203. The exposure head 106 and the photosensitive drum 102 are each attached to the image forming apparatus 10 by attachment members (not shown).

[0029] The exposure head 106 is composed of a light-emitting element group 201, a printed circuit board 202 on which the light-emitting element group 201 is mounted, a rod lens array 203, and a housing 204 on which the rod lens array 203 and the printed circuit board 202 are attached. The exposure head 106 is fixed so that light emitted from the light-emitting element group 201 is imaged on the photosensitive drum 102 via the rod lens array 203.

[0030] Configuration of printed circuit board 202 FIG. 4 is a diagram illustrating the configuration of the printed circuit board 202. As shown in FIG.

[0031] A group of light emitting elements 201 is mounted on a printed circuit board 202 .

[0032] Figure 4(a) shows the side opposite to the side on which the light-emitting element group 201 is mounted (hereinafter referred to as the light-emitting element non-mounting side), and Figure 4(b) shows the side on which the light-emitting element group 201 is mounted (hereinafter referred to as the light-emitting element mounting side).

[0033] The light emitting element group 201 is configured by arranging a plurality of light emitting elements 602 (602-1 to 602-m). The light emitting elements 602 are arranged in the longitudinal direction of the light emitting element mounting surface of the printed circuit board 202 at a predetermined resolution pitch.

[0034] The longitudinal direction of the light-emitting element mounting surface of the printed circuit board 202 is along the axial direction of the photosensitive drum 102, and the light-emitting elements serving as light-emitting units are arranged in a direction along the longitudinal direction of the photosensitive drum 102. In other words, the light-emitting element 602 corresponds to the light-emitting unit.

[0035] In this embodiment, the pitch of adjacent light emitting elements in the longitudinal direction of the light emitting element mounting surface of the printed circuit board 202 is a pitch (approximately 21.16 μm) corresponding to a resolution of 1200 dpi.

[0036] Furthermore, the light emitting element group 201 is configured with an array of n=14173 light emitting elements 602, thereby enabling image formation corresponding to an image width of approximately 300 mm in the longitudinal direction of the photosensitive drum 102.

[0037] The intervals between the light emitting elements 602 and the number of the light emitting elements 602 are merely examples in this embodiment, and are not limited to the pitch and number of the resolution described above.

[0038] On the surface where the light emitting elements are not mounted, there are arranged a control signal from the image controller unit 700 that controls the light emitting element driving unit 400, and a power supply 300, and a connector 305 that connects the light emitting element driving unit 400. Control signals input to the light emitting element driving unit via the connector 305 include, for example, a clock signal 705, a synchronization signal 706, and a data signal 707. The power supply 300 connected to the connector 305 supplies the light emitting element driving unit 400 with power to drive the light emitting element driving unit 400.

[0039] FIG. 5 is a block diagram showing the configuration of the image controller unit 700 and the printed circuit board 202. As shown in FIG.

[0040] In this embodiment, to simplify the explanation, we will explain single-color processing, but the same processing is also performed in parallel simultaneously for four colors: cyan (C), magenta (M), yellow (Y), and black (K).

[0041] The image controller unit 700 outputs a signal to the printed circuit board 202 to control the light emitting element drive unit 400 in response to an instruction from the printer control unit 708. This signal includes a clock signal 705, a synchronization signal 706 indicating the start timing of communication data, and a data signal 7707, which will be described later.

[0042] The data signal 707 includes at least one of image data for controlling the on / off of the light emitting element 602 and data to be written to a register of the light emitting element driving unit 400 .

[0043] The clock signal 705 , the synchronization signal 706 , and the data signal 707 are output to the light emitting element driving section 400 via the connector 305 .

[0044] The image controller unit 700 includes an image data generating unit 701, a communication control unit 702, and a CPU 703, and performs processing on image data and processing on print timing.

[0045] The image data generation unit 701 performs dithering processing on image data received from the scanner unit 100 or from outside the image forming apparatus 10 at a resolution instructed by the CPU 703 to generate image data for print output. In this embodiment, dithering processing is performed at a resolution of 1200 dpi in the longitudinal direction (main scanning direction) of the light-emitting element mounting surface of the printed circuit board 202 and 1200 dpi in the sub-scanning direction, in accordance with the pitch of the light-emitting elements 602. The image data represents on / off as a binary value, and the on / off of the light-emitting elements 602 is controlled based on the image data.

[0046] The image data generation unit 701 performs dithering processing on the image data and then outputs the image data to the communication control unit 702 .

[0047] The synchronization signal 706 is a line synchronization signal that is output in synchronization with the clock signal 705 .

[0048] The synchronization signal 706 is generated with one period being the period in which the surface of the photosensitive drum 102 moves a pixel size of 1200 dpi (approximately 21.16 μm) in the rotation direction at a predetermined rotation speed of the photosensitive drum 102.

[0049] The communication control unit 702 outputs the image data generated by the image data generation unit 701 to the light emitting element driving unit 400 in synchronization with a synchronization signal 706 .

[0050] Furthermore, when the communication control unit 702 is requested by the CPU 703 to output the register setting value to the light emitting element driving unit 400 , it outputs the register setting value to the light emitting element driving unit 400 in synchronization with the synchronization signal 706 .

[0051] The image controller unit 700 includes an image data generation unit 701 and a communication control unit 702. The communication control unit 702 outputs the image data generated by the image generation unit 701 in synchronization with a synchronization signal, which is a signal with a predetermined period. In other words, the image controller unit 700 corresponds to a generation unit.

[0052] When the CPU 703 receives the emergency stop signal 704 from the printer control unit 708, it controls the image data generation unit 701 to generate and output white image data indicating that the light emitting elements 602 are turned off, thereby turning off the light emitting element group 201. Details will be described later.

[0053] By turning off the light emitting element group 201 at the time of emergency stop, it is possible to prevent the light emitting element group 201 from continuously exposing the same point on the stopped photosensitive drum 102.

[0054] This series of control operations by the CPU 703 will be described in detail with reference to the flowchart of Figure 6 and Figure 7. The processing of this flowchart is executed by the CPU 703.

[0055] When a print operation is started in response to an instruction from the printer control unit 708, the CPU 703 performs a register setting operation. By performing an operation to output a register setting value from the communication control unit 702 to the light emitting element driving unit 400 in response to an instruction from the CPU 703, the setting information of the drive current for driving the light emitting element 602 is changed (S1101). Next, the CPU 703 instructs the image data generating unit 701 to generate image data. As a result, image data with a resolution of 1200 dpi in both the main scanning and sub-scanning directions is generated (S1102). Thereafter, the CPU 703 controls the communication control unit 702 to output the image data generated by the image data generation unit 701 at a predetermined cycle, thereby starting image generation. The predetermined cycle corresponds to, for example, the cycle of the synchronization signal 706 (S1103). The CPU 703 performs this operation line by line in the main scanning direction until the final line is reached, thereby forming an image for one page (S1104). Furthermore, if the CPU 703 receives an emergency stop signal 704 during exposure, the image controller unit 700 stops outputting the image data generated in S1102. Then, the communication control unit 702 outputs white image data, generated by the image data generation unit 701, indicating that the light emitting element 602 is turned off, to the light emitting element drive unit 400.

[0056] The communication control unit 702 turns off the light-emitting element group 201 by transmitting white image data to the light-emitting element driving unit 400. As a result, it is possible to prevent the light-emitting element group 201 from continuously exposing the same point on the photosensitive drum 102.

[0057] FIG. 7 is a diagram illustrating the processing in S1106.

[0058] If the CPU 703 does not receive the emergency stop signal 704 during the image data output, it outputs additional white image data after outputting the image data of the last line, thereby stopping the light emission of the light emitting element group 201 (S1106). Finally, it is determined whether the series of printing operations has been completed, and if there is a next page, the process returns to S1101, and the same process is repeated to perform a continuous printing operation (S1107). The image data generated by this series of controls is output from the communication control unit 702 to the light emitting element driving unit 400. The light emitting element driving unit 400 operates based on a clock signal 705, a synchronization signal 706, and a data signal 707 output from the communication control unit 702.

[0059] A signal line is connected from the light emitting element driving unit 400 to each light emitting element of the light emitting element group 201, and light emission is controlled by this.

[0060] As shown in FIG. 8, if the emergency stop signal 704 is input at a timing other than when image data is being output, the light emission of the light-emitting element group 201 has stopped, so the operation of outputting white image data again may be stopped. Circuit block of the light emitting element driving unit 400 9 shows a circuit block diagram in the light emitting element driving section 400. The circuit section 406 in the light emitting element driving section 400 is made up of a digital section 800 and an analog section 806.

[0061] The digital unit 800 receives the clock signal 705, synchronization signal 706, and data signal 707 output from the image controller unit 700 at a receiving unit 801. When the received content is image data, the digital unit 800 has a function of generating lighting signals 808 (808-1 to 808-n) for lighting the light emitting elements 602 and sending the lighting signals 808 to the analog unit 806.

[0062] Furthermore, if the received data signal 707 is a register setting value, the register setting value is stored in the register unit 802, and the setting for controlling the operation of the analog unit 806 is changed. The register unit 802 outputs a register signal 807 to the analog unit 806 to control the operation of the analog unit 806. The operation of the analog unit controlled by the register unit includes, for example, setting information for the drive current with which the drive unit 1601 drives the light emitting element 602.

[0063] The analog section 806 generates a signal required to drive the light emitting element 602 based on the lighting signal 808 generated by the digital section 800 .

[0064] 10 shows a block diagram of the analog unit 806. In this embodiment, for the sake of simplicity, only two light-emitting elements 602-1 and 602-2 and two driving units 1601-1 and 1601-2 are shown and explained, but it is assumed that similar driving units are formed corresponding to all the light-emitting elements 602 in the light-emitting element group 201.

[0065] First, a register signal 807 output based on data set in a register unit 802 is input to a DAC 1602 (digital-analog converter).

[0066] Next, an analog voltage 1603 that determines the drive current of light-emitting elements 602-1 and 602-2 is supplied to drive units 1601-1 and 1601-2. Next, a lighting signal 808-1 is input to drive unit 1601-1, and a lighting signal 808-2 is input to drive unit 1601-2. Thereafter, each light-emitting element (602-1, 602-2) begins to emit light independently by the drive circuits described below, based on the analog voltage 1603 and lighting signal 808-1 in drive unit 1601-1 and the analog voltage 1603 and lighting signal 808-2 in drive unit 1601-2.

[0067] 11 is a diagram showing the configuration of the driver 1601-1. Note that the driver sections (for example, 1601-2) for the other light-emitting elements 602 are also driven by similar circuits. The MOSFET 1702 supplies a drive current to the light-emitting element 602-1 in accordance with the gate voltage value, and controls the current so that the drive current is turned off (light is turned off) when the gate voltage is at a low level.

[0068] An analog voltage 1603 is connected to the drain of the MOSFET 1704, and when the drive signal 401 is Hi, the MOSFET 1704 is turned on and transfers the voltage charged in the capacitor 1706 to the MOSFET 1702. In this embodiment, the DAC 1602 sets an analog voltage in the capacitor 1706 at a timing before image formation, and the set analog voltage level of the capacitor 1706 is maintained during the image formation period. By the above operation, the MOSFET 1702 supplies a drive current to the light emitting element 602-1 in accordance with the set analog voltage level of the capacitor 1706 and the drive signal 401, thereby causing the light emitting element 602-1 to emit light.

[0069] A signal obtained by logically inverting the lighting signal 808 by an inverter 1705 is input to the gate of the MOSFET 1703. As a result, when the lighting signal is low, the MOSFET 1703 is turned on, and plays a role in accelerating the response speed until the light emission stops by forcibly discharging the charge stored in the input capacitance of the light emitting element 602-1.

[0070] As described above, in a configuration including the detection means and the generation unit as in this embodiment, even when the maintenance door 104 is open, power is supplied to the light-emitting element drive unit 400 from the power source 300. Furthermore, when the maintenance door 104 is opened during an image formation job, the image controller unit 700 outputs image data indicating that the light-emitting element 602 is turned off to the light-emitting element drive unit 400. The light-emitting element drive unit 400 controls the light emission of the light-emitting element 602 based on the image data. As a result, the light-emitting element 602 does not emit light, making it possible to suppress the formation of unintended latent images on the surface of the photosensitive drum.

[0071] One possible method for preventing the light-emitting element 602 from emitting light when the photosensitive drum 102 stops is to cut off power to the light-emitting element drive unit 400. However, with this configuration, a potential difference between the image controller unit 700 and the light-emitting element drive unit 400 could cause an unexpected voltage to be applied from the image controller unit 700 to the light-emitting element drive unit 400. This could result in a malfunction of the light-emitting element drive unit 400. To prevent the light-emitting element drive unit 400 from malfunctioning due to the potential difference, a protection circuit could be provided between the light-emitting element drive unit 400 and the image controller unit 700. However, providing a protection circuit would increase costs. On the other hand, in this embodiment, power is supplied to the light-emitting element drive unit 400 even when the maintenance door 104 is open, and image data indicating that the light-emitting element 602 is turned off is output to the light-emitting element drive unit 400. In other words, the configuration of this embodiment can prevent malfunction of the light-emitting element drive unit 400, suppress an increase in costs, and suppress the formation of unintended latent images on the surface of the photosensitive drum. [Explanation of symbols]

[0072] 102 Photosensitive drum 105 Paper feed / transport section 106 Exposure head 107 Charger 110 Register Roller 114 Maintenance Door 201 Light emitting element group 300 power supply 400 Light emitting element driving unit 602 Light-emitting element 700 Image controller 701 Image data generation unit 702 Communication control unit 703 CPU 706 Sync Signal 707 Data Signal 708 Printer control unit 1601 Drive unit

Claims

1. In an image forming apparatus for forming an image on a recording medium, a photosensitive drum that rotates around a rotation axis; a plurality of light-emitting units arranged along the rotation shaft and emitting light to expose a photosensitive layer provided on the photosensitive drum; a maintenance door that can be opened to expose the inside of the image forming apparatus; a driver that drives the light-emitting unit based on image data; a register unit provided in the drive unit and storing control data indicating target light intensities of the plurality of light-emitting units; a power supply that supplies power to the drive unit for operating the drive unit; Equipped with the plurality of light-emitting units are turned off when the maintenance door is opened, When the maintenance door is opened, the supply of power to the drive unit is not interrupted. An image forming apparatus characterized by:

2. The image forming apparatus according to claim 1, further comprising a detection means for detecting the opening of the maintenance door.

3. The image forming device further includes a generation unit that generates image data for controlling the lighting of the plurality of light-emitting units, 3. The image forming apparatus according to claim 2, wherein the generating unit generates and outputs image data indicating that the light emitting unit is to be turned off when the detecting unit detects that the maintenance door is open.

4. The image forming apparatus further includes a transport path for transporting the recording medium, the generating unit generates and outputs image data indicating that the light emitting unit is turned off when a jam of the recording medium occurs in the transport path.

4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

5. The image forming apparatus according to claim 1, wherein the drive unit further comprises an analog unit that operates in response to an analog signal.

6. The image forming apparatus described in Claim 5, characterized in that the driving unit further includes a digital-to-analog converter that controls the value of the current supplied to the multiple light-emitting elements based on a digital signal.

7. An image forming apparatus as described in Claim 6, characterized in that the digital-to-analog converter controls the value of the current supplied to the multiple light-emitting elements based on the control data stored in the register unit.

8. An image forming apparatus as described in claim 1, characterized in that the multiple light-emitting elements are organic EL.

Images