JP2007057625A - Image recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can be miniaturized. <P>SOLUTION: A representative configuration of an image recorder is characterized in that a high voltage peripheral circuit board 131 is arranged on a scanner unit stay 130 in the image forming apparatus including; a laser scanner unit 107 for causing laser light to scan on a photoreceptor drum 117; a CRG 108 for transferring a toner image formed on the photoreceptor drum 117 to a recording sheet; the high voltage peripheral circuit board 131 including a high voltage driving circuit part for driving the CRG 108, a peripheral circuit part 131b for general control of the image forming apparatus, and an opening 131c for irradiating the photoreceptor drum 117 with laser light; and the scanner unit stay 130 for arranging the laser scanner unit 107. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image recording apparatus using an electrophotographic process such as a copying machine or a laser printer.

  FIG. 6 is a block diagram of an image recording apparatus such as a laser beam printer using a conventional electrophotographic process. As shown in FIG. 6, the arrangement of the conventional image recording apparatus is such that the laser scanner unit 107, the scanner unit stay 130, the image forming unit (CRG) 108, the sheet conveyance path 127, and the control board 126 are arranged in this order from the top of the main body. It is an arrangement configuration.

Japanese Patent Laid-Open No. 06-202398 (FIG. 1)

  In the configuration of the conventional example, circuit components such as the high-voltage drive circuit portion 126a, the peripheral circuit portion 126b, and the power supply circuit portion 126c are mounted on the control board 126.

  In such a configuration, the high-voltage drive circuit portion 126a and the power supply circuit portion 126c have a large part shape, so that a large space for arranging the control board 126 is necessary, and the apparatus is increased in size. There was a problem.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of downsizing the apparatus.

  In order to solve the above problems, a typical configuration of an image recording apparatus according to the present invention includes a scanning optical device that scans an image carrier with a laser beam, and a toner image formed on the image carrier. A high-voltage drive circuit unit that drives the image forming unit, a control circuit unit that performs general control of the image forming apparatus, and an opening for irradiating the image carrier with laser light In an image forming apparatus having a peripheral circuit board and an arrangement unit for arranging the scanning optical device, the high-voltage peripheral circuit board is arranged on the arrangement unit.

  According to the present invention, the apparatus can be miniaturized.

[First embodiment]
A first embodiment of an image recording apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an image recording apparatus using an electrophotographic process according to the present embodiment. 2A is a side view of the upper portion of the image recording apparatus, FIG. 2B is a front view, and FIG. 2C is a top view.

(Overall configuration of image forming apparatus)
As shown in FIG. 1, the image forming apparatus includes a laser beam printer main body 101 and a laser scanner unit 107 which is a scanning optical device.

  The unit 107 includes a laser unit 113, a polygon motor 114a, a polygon mirror 114b, and imaging lenses 115 and 116. The laser unit 113 emits laser light modulated based on an image signal (image signal VDO). Laser light emitted from the laser unit 113 is polarized by a polygon mirror 114b rotated by a polygon motor 114a, and scanned on a photosensitive drum 117, which is an image carrier, via an imaging lens 115 and a folding mirror 116.

  The main body 101 includes a cassette 102, a feeding roller 105, a registration roller pair 106, an image forming unit ((cartridge, hereinafter referred to as CRG)) 108, and a fixing device 109. Further, the printer includes a discharge roller 111, a stacking tray 112, a transfer roller 121, a main motor 123, a scanner unit stay 130 which is an arrangement unit, a high voltage peripheral circuit board 131, and a power supply circuit board 132.

  The recording sheet S stored in the cassette 102 is guided to the sheet conveyance path 127 by the feeding roller 105 and fed to the registration roller pair 106. The fed recording sheet S is guided along the sheet conveying path 127 by the registration roller pair 106 and is synchronously conveyed to the CRG 108 (nip portion between the photosensitive drum 117 and the transfer roller 121).

  The CRG 108 includes a photosensitive drum 117, a primary charging roller 119, a developing device 120, and a cleaner 122 necessary for a known electrophotographic process. The CRG 108 forms a toner image on the recording sheet S based on the laser light from the unit 107. The primary charging roller 119 applies a voltage to the photosensitive drum 117 and uniformly charges it. The uniformly charged 117 is exposed to a laser beam to form an electrostatic latent image. The developing device 120 applies toner to the electrostatic latent image to form a toner image. After transferring the toner image, the cleaner 122 removes residual toner remaining on the photosensitive drum 117 and cleans the photosensitive drum 117. The recording sheet S conveyed to the nip portion is transferred with a toner image to form an image.

  The recording sheet S on which an image is formed by the CRG 108 is conveyed to the fixing device 109. The fixing device 109 includes a fixing film 109a, a pressure roller 109b, a ceramic heater 109c having a heating element provided inside the fixing film, and a thermistor 109d that detects the surface temperature of each heating element of the ceramic heater 109c. . The recording sheet S conveyed to the fixing device 109 fixes the toner image by heat and pressure. The recording sheet S on which the toner image is fixed is discharged to the stacking tray 112 by the discharge roller 111 and stacked.

  The main motor 123 applies a driving force to the feeding roller 105 via the feeding roller clutch 124, and applies a driving force to the registration roller pair 106 via the registration roller 125. Further, the main motor 123 applies driving force to the CRG 108, the fixing device 109, and the discharge roller 111.

  The scanner unit stay 130 is made of metal or the like, and is provided on the upper surface of the CRG 108. A unit 107 is disposed above the stay 130. The stay 130 is provided with a laser irradiation opening 130 a for irradiating the photosensitive drum 117 of the CRG 108 with laser light from the laser unit 113.

(Arrangement of high-voltage peripheral circuit board 131 and power supply circuit board 132)
A high voltage peripheral circuit board 131 is placed on the scanner unit stay 130 (between the stay 130 and the unit 107). The high-voltage peripheral circuit board 131 includes a high-voltage drive circuit unit 131a and a peripheral circuit unit 131b that is a control circuit unit.

  The high-voltage drive circuit unit 131a is composed of a high-voltage circuit that drives the electrophotographic process. The peripheral circuit unit 131b performs general control of the image forming apparatus such as sheet conveyance control.

  The high-voltage drive circuit unit 131a is composed of tall components, and the peripheral circuit unit 131b is composed of short components around the CPU. As shown in FIGS. 1 and 2B, the high-voltage drive circuit unit 131 a is disposed beside the unit 107, and the peripheral circuit unit 131 b is disposed below the unit 107.

  The high-voltage peripheral circuit board 131 has an opening 131 c for irradiating the photosensitive drum 117 with laser light from the unit 107.

  Under the CRG 108, a charging contact 108a and a developing contact 108b, which are contact portions for applying a high voltage, are provided. The high-voltage drive circuit unit 131a applies a charging voltage to the primary charging roller 119 via the charging contact spring 170 and the charging contact 108a. The high voltage driving circuit 126a applies a developing voltage to the developing device 120 via the developing contact spring 171 and the developing contact 108b. The high-voltage drive circuit unit 131a applies a transfer voltage to the transfer roller 121 via the transfer contact spring 172 and the like. Note that energization from the charging contact 108 a and the development contact 108 b to the primary charging roller 119 and the transfer roller 121 is performed by wiring in the CRG 108.

  The power supply circuit board 132 has a power supply circuit portion 132c. The power circuit board 132 is provided below the sheet conveyance path 127 (the lowest part of the main body 101). The power supply circuit board 132 may be provided on the side surface of the main body 101.

  As described above, the image recording apparatus is arranged in the order of the unit 107, the high-voltage peripheral circuit board 131, the stay 130, the CRG 108, the sheet conveyance path 127, and the power supply circuit board 132 from the upper part of the main body.

  With this configuration, the space on the stay 130 and the space around the unit 107 can be used effectively, and the image forming apparatus can be downsized.

[Second Embodiment]
Next, a second embodiment of the image recording apparatus according to the present invention will be described with reference to the drawings. FIG. 3 is a three-dimensional layout of the CRG 108, the scanner unit stay 130, the high-voltage peripheral circuit board 131, and the unit 107 according to this embodiment. 4 is a cross-sectional view of FIG. 3 as viewed from the front. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the image forming apparatus of the present embodiment, in the configuration of the first embodiment, the charging contact 108 a and the development contact 108 b are arranged above the CRG 108 and below the high-voltage peripheral circuit board 131.

  A charging contact spring 180 is provided from the lower portion of the high-voltage driving circuit portion 131 a of the high-voltage peripheral circuit board 131 and is in contact with the charging contact 108 a on the CRG 108.

  FIG. 5 shows an example of a charging contact portion with the high voltage peripheral circuit board 131. As shown in FIG. 5A, solder 190 is soldered on the pattern of the high-voltage peripheral circuit board 131 without using a resist. As shown in FIG. 5B, the charging contact spring 180 comes into contact with the solder 190. Similarly, the developing contact spring 181 is energized with the pattern of the high-voltage peripheral circuit board 131 through the solder 190.

  In this way, the contacts (charging contacts 108a and developing contacts 108b) between the CRG 108 and the high-voltage peripheral circuit board 131 are arranged in the upper part. Thereby, it is not necessary to provide a member for preventing the toner from dropping to the charging contact 108a and the developing contact 108b, and contact failure can be prevented at low cost.

1 is a configuration diagram of an image recording apparatus according to a first embodiment. FIG. 6 is a layout diagram around a scanner unit stay. FIG. 6 is a three-dimensional layout diagram of an image forming unit, an arrangement unit, a high-voltage peripheral circuit board, and a scanning optical device according to a second embodiment. It is sectional drawing of the scanner unit stay periphery concerning 2nd embodiment. It is a figure of the board | substrate side contact part concerning 2nd embodiment. It is a block diagram of the conventional image recording apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS S ... Recording sheet | seat 101 ... Laser beam printer main body, 102 ... Cassette, 105 ... Feed roller, 106 ... Registration roller pair, 107 ... Laser scanner unit (corresponding to a scanning optical apparatus), 108 ... Image forming part, 108a ... Charging Contact (corresponding to the contact portion), 108b ... Development contact (corresponding to the contact portion), 109 ... Fixing device, 109a ... Fixing film, 109b ... Pressure roller, 109c ... Ceramic heater, 109d ... Thermistor, 111 ... Discharge roller, 112 DESCRIPTION OF SYMBOLS ... Loading tray, 113 ... Laser unit, 114a ... Polygon motor, 114b ... Polygon mirror, 115 ... Imaging lens, 116 ... Folding mirror, 117 ... Photosensitive drum (corresponding to image carrier), 119 ... Primary charging roller, 120 ... Developer 121 ... Transfer roller 122 ... Cleaner 123 ... Main mode , 124 ... feed roller clutch, 125 ... registration roller, 126 ... control board, 127 ... sheet conveyance path, 130 ... scanner unit stay (corresponding to arrangement means), 130a ... laser irradiation opening, 131 ... high voltage peripheral circuit board, 131a: High-voltage drive circuit unit 131b: Peripheral circuit unit (corresponding to the control circuit unit) 131c: Opening part 132: Power circuit board 170: Charging contact spring 171: Development contact spring 172: Transfer contact spring 172 ... Spring, 180 ... Charge contact spring, 181 ... Development contact spring, 182 ... Transfer contact spring, 190 ... Solder

Claims (4)

A scanning optical device that scans the image carrier with laser light;
An image forming unit that transfers a toner image formed on the image carrier to a recording sheet;
A high-voltage peripheral circuit board having a high-voltage drive circuit unit that drives the image forming unit, a control circuit unit that performs general control of the image forming apparatus, and an opening for irradiating the image carrier with laser light;
In an image forming apparatus having an arrangement unit for arranging the scanning optical device,
An image forming apparatus, wherein the high-voltage peripheral circuit board is arranged on the arranging means. The image forming apparatus according to claim 1, wherein the high-voltage drive circuit unit is arranged between the arrangement unit and the scanning optical device. The image forming apparatus according to claim 1, wherein the control circuit unit is disposed beside the scanning optical device.   4. The image recording apparatus according to claim 1, further comprising a contact portion between the image forming portion and the high-voltage drive circuit portion in a vertical direction above the image forming portion.

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