JP2007313687A - Image forming apparatus and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely and electrically couple a transfer roller or the like to a power supply circuit board without increasing the number of components in a laser beam printer. <P>SOLUTION: An elastic conduction member is disposed at a portion from the transfer roller to a land section 40 of the power supply circuit board 12, thereby electrically coupling them. The land section 40 comprises a plurality of first land sections 41 arranged in a direction perpendicular to a dipping direction of the power supply circuit board 12, a second land section 42 provided parallel to the dipping direction to electrically couple the first land sections 41 to each other, and a third land section 43 provided at the downstream side of the first land sections 41 in the dipping direction to surround the first land sections 41 and to be electrically coupled to the second land section 42. A flat solder pad 45 having a uniform thickness is formed on the surfaces of the first land sections 41 by solder dipping, thereby improving the electric conduction to the elastic conduction member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on a recording sheet, and an electronic apparatus including a power supply circuit board that supplies power to each portion.

  Conventionally, in laser beam printers, the tip of the wire extended from each part of the transfer roller, charger, developer, etc. is connected to the power circuit board by screwing or soldering to supply power to the transfer roller, etc. is doing. In such a configuration, it takes time and labor for screwing and soldering, which increases the cost of the printer. Accordingly, various configurations have been studied in which power can be supplied to the transfer roller or the like without screwing or soldering.

  For example, as shown in FIG. 7, there is a printer configured to supply electric power to each portion by a conductive member disposed from a transfer roller or the like to a power circuit board. In such a configuration, the jumper wire 120 disposed on the component mounting surface of the power circuit board 112 is brought into contact with the tip 131 of the conducting member 130 so as to ensure conduction between the two. However, even with such a configuration, the number of parts cannot be reduced because the jumper wires 120 must be provided on the power circuit board 112 in accordance with the number of parts that need to be fed.

In Patent Document 1, a dummy land portion is provided in the vicinity of a land portion on which an electronic component is mounted via a connecting portion, thereby suppressing solder swell and mounting the electronic component in a close contact state. A circuit board is shown. Patent Document 2 discloses a circuit board that suppresses a solder bridge by forming a widest solder pad among a plurality of adjacent solder pads and partitioning the wide solder pad with silk. Has been. Patent Document 3 discloses a circuit board on which solder pads having different heights are formed by arranging a mask having openings of different sizes on a land pattern and performing solder reflow.
JP-A-10-290065 JP 2004-71992 A JP-A-6-37436

  The present invention has been made in order to solve the above-described problems, and an image forming apparatus capable of reducing costs by reliably connecting a transfer roller and the power circuit board without increasing the number of components, and An object is to provide electronic equipment.

In order to achieve the above object, the invention according to claim 1 is a photoconductor drum having a photoconductor coated on the surface, a charging means for uniformly charging the surface of the photoconductor drum, and a laser beam scanned on the surface of the photoconductor. Exposure means for forming a latent image by irradiation, developing means for forming a toner image by attaching toner to a portion of the surface of the photosensitive member where the latent image is formed, and development in the rotational direction of the photosensitive drum The toner image formed on the surface of the photosensitive drum is formed on the surface of the recording drum by charging the surface of the recording drum at a predetermined transfer position downstream of the means so as to face the surface of the photosensitive drum. Transfer means for transferring the toner image, fixing means for fixing the toner image on the recording paper by applying predetermined heat and pressure to the recording paper on which the toner image has been transferred, conveying means for conveying the recording paper to the transfer position, and a photoconductor Drum, charging means, dew Image forming apparatus including a power supply circuit board for supplying electric power to a photosensitive drum, a charging unit, an exposure unit, a developing unit, a transfer unit, and a fixing unit. And an elastic conductive member having elasticity provided from a position facing each of the power supply circuit boards from each of the above means for conducting at least one of the transfer means and the power supply circuit board. Has a land portion that forms a part of the power supply circuit at a position facing the tip portion of the elastic conducting member, and a plurality of land portions are arranged in a direction orthogonal to the dipping direction of the power supply circuit board. A land portion and a second land portion disposed in a direction parallel to the dipping direction of the power circuit board to electrically connect the first land portions to each other; and a power supply circuit for the first land portion Downstream of the dipping direction of the plate, is disposed to surround the first land portion includes a third land portion which is electrically connected to the second land portions,
The second land portion is formed thinner than the first land portion, solder pads having a flat cross section are formed on the surfaces of the first land portion and the second land portion, and the power circuit board is formed from the molten solder bath. When the solder is pulled up, the solder flows into the third land portion located on the downstream side of the first land portion, so that the thickness of the solder pad formed on the surface of each first land portion is made uniform and elastic conduction is achieved. When the tip of the elastic conducting member is pressed toward the solder pad by the elastic force of the member and the tip of the elastic conducting member comes into contact with the solder pad, the contact area is increased and the elastic conduction Among the photosensitive drum, charging means, exposure means, developing means, transfer means, fixing means, and conveying means, without preventing poor conduction between the tip of the member and the solder pad, thereby increasing the number of parts. Small Kutomo one, is obtained by reliably enable conduction between the power supply circuit board.

  According to a second aspect of the present invention, there is provided an electronic apparatus including a power supply circuit board for supplying electric power so as to connect each part of the device and the power supply circuit board over a position facing each of the power supply circuit boards from each part of the device. And a plurality of first land portions arranged in a direction orthogonal to the dipping direction of the power circuit board at a position facing the tip of the elastic conduction member. And a second land portion disposed in a direction parallel to the dipping direction of the power supply circuit board for electrically connecting the first land portions to each other, and the surfaces of the first land portion and the second land portion Is formed with a solder pad having a flat cross section, and the tip of the elastic conductive member is pressed against the solder pad by the elastic force of the elastic conductive member, so that the tip of the elastic conductive member and the solder pad are in contact with each other. Threaded, whereby, without increasing the number of parts is obtained by the respective units, and reliably enable conduction between the power supply circuit board.

  According to a third aspect of the present invention, in the electronic device according to the second aspect, the first land portion is disposed on the downstream side in the dipping direction of the power circuit board with respect to the first land portion, and the second land portion is disposed. And a solder formed on the surface of each first land portion by flowing the solder into the third land portion when the power circuit board is pulled up from the molten solder bath. The pad thickness is made uniform.

  According to the first aspect of the present invention, the tip of the elastic conductive member is pressed by the elastic force of the elastic conductive member and brought into contact with the solder pad. The photosensitive drum and the power supply circuit board can be reliably conducted without increasing the number of points. Thereby, the cost of the image forming apparatus can be reduced. In addition, since a plurality of the first land portions are arranged in a direction orthogonal to the dipping direction of the power circuit board, solder pads having a flat cross section are formed on the surfaces of the first land portion and the second land portion. The Here, since the second land portion is formed thinner than the first land portion, the thickness of the solder pad on the second land portion is smaller than the thickness of the solder pad on the first land portion. As a result, the contact area between the solder pad on the first land portion and the tip of the elastic conduction member is increased, and the conduction between the two is good. In addition, since the third land portion is disposed on the downstream side in the dipping direction of the power circuit board with respect to the first land portion, when the power circuit board is pulled up from the molten solder bath, an extra portion is added to the third land portion. Solder flows in, and the thickness of the solder pads formed on the surface of each first land portion is made uniform. Thereby, conduction between the solder pad on the first land portion and the tip of the elastic conduction member is further improved. Furthermore, since the third land portion is formed so as to surround the first land portion, the third land can be formed even in a small empty space on the power supply circuit board, and the degree of freedom of the power supply circuit board is increased. In addition to the increase, the size of the image forming apparatus can be reduced.

  According to the second aspect of the present invention, the tip of the elastic conductive member is pressed by the elastic force of the elastic conductive member and brought into contact with the solder pad. The photosensitive drum and the power supply circuit board can be reliably conducted without increasing the number of points. Thereby, the cost reduction of an electronic device can be aimed at. In addition, since a plurality of first land portions are arranged in a direction orthogonal to the dipping direction of the power circuit board, and the second land portions are arranged in a direction parallel to the dipping direction, the surface of the first land portion A solder pad having a flat cross section is formed. As a result, the contact area between the solder pad on the first land portion and the tip of the elastic conduction member is increased, and the conduction between the two is good.

  According to the invention of claim 3, since the third land portion is disposed downstream of the first land portion in the dipping direction of the power circuit board, when the power circuit board is pulled up from the molten solder bath, Excess solder flows into the third land portion, and the thickness of the solder pad formed on the surface of each first land portion is made uniform. Thereby, conduction between the solder pad on the first land portion and the tip of the elastic conduction member is further improved. Furthermore, since the third land portion is formed so as to surround the first land portion, the third land can be formed even in a small empty space on the power supply circuit board, and the degree of freedom of the power supply circuit board is increased. In addition to the increase, the electronic device can be downsized.

  An image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows a laser beam printer 1 which is a configuration example of an image forming apparatus. A laser beam printer 1 includes a photosensitive drum 2, a cleaner 3, a charger 3, a charger (charging means) 4, a laser scanning unit (exposure means) 5, a developing brush (developing means) 6, and a transfer roller. (Transfer means) 7, a fixing roller (fixing means) 8 disposed downstream of the transfer roller 7 in the conveying direction of the recording paper P, and a paper feed tray (recording paper holding means) loaded with the recording paper P 9, a paper discharge unit 10 on which the printed recording paper P is deposited, a recording paper transport mechanism (transport means) 11 for transporting the recording paper P loaded in the paper feed tray 9 to the position of the photosensitive drum 2, and each part of the apparatus The power supply circuit board 12 (see FIG. 2) and the like for supplying power to the power supply. Each of the above components is mounted on a metal frame 13 disposed on the bottom of the laser beam printer 1 or the like. The frame 13 is provided with a cover 14 that covers each of the above components and forms the exterior of the laser beam printer 1, and on the rear side thereof, the recording paper P jammed in the recording paper transport mechanism 11 is removed or A door member 15 for exchanging a toner cartridge 17 described later is provided so as to be freely opened and closed.

  The cleaner 3 removes toner and paper dust before one stroke (one rotation) adhering to the surface of the photosensitive drum 2 and cleans the drum surface. The charger 4 uniformly charges the surface of the photosensitive drum 2 cleaned by the cleaner 3. The laser scan unit 5 forms a latent image by irradiating the surface of the photosensitive drum 2 charged by the charger 4 while scanning the laser beam L. The developing brush 6 is attached to a toner cartridge 17 filled with toner, and forms a toner image by attaching toner to a portion of the surface of the photosensitive drum 2 where a latent image is formed. The transfer roller 7 is provided so as to face the surface of the photosensitive drum 2, and charges the surface of the recording paper P while pressing the recording paper P against the surface of the photosensitive drum 2, so that the surface of the photosensitive drum 2 is charged. The formed toner image is transferred onto the recording paper P. Electric power necessary for the transfer is supplied from the power supply circuit board 12. The recording paper P on which the image is formed on the surface by the transfer roller 7 is conveyed to the fixing roller 8. The fixing roller 8 fixes the toner by applying heat and pressure while sandwiching the recording paper P together with the pressing roller 16 disposed opposite to the fixing roller 8. Heat for fixing the toner is supplied from a heater (for example, a halogen lamp) built in the fixing roller 8. A fixing voltage generated by the power supply circuit board 12 is applied to the heater. The recording paper transport mechanism 11 has a pick roller 21 that sends out the recording paper P loaded in the paper feed tray 9. The pick roller 21 is rotatably supported by the frame member 23 via the rotation shaft 22.

  FIG. 2 shows the configuration of the transfer roller 7, the power supply circuit board 12, and the vicinity thereof. A feeding terminal 7 a for supplying power for transfer is attached to the edge of the transfer roller 7. Further, an elastic conducting member 30 formed by processing a metal bar is mounted between the power supply terminal 7a and the power supply circuit board 12.

  FIG. 3 shows the elastic conductive member 30 and its peripheral configuration. The elastic conducting member 30 is a torsion coil spring portion that is rotatably supported by a terminal contact portion 30a that is in contact with the power supply terminal 7a and a support member 50 that is coupled to a part of the frame 13 of the laser beam printer 1. 30 b and a coil spring portion (tip portion) 30 c that comes into contact with the power supply circuit board 12. By the torsion coil spring portion 30b and the coil spring portion 30c, elasticity required for contact conduction between the power supply terminal 7a and the terminal contact portion 30a and contact conduction between the solder pad 45 formed on the power supply circuit board 12 and the coil spring portion 30c. Is applied to the elastic conducting member 30. Although only the connection between the transfer roller 7 and the power supply circuit board 12 is shown in FIG. 3, the charger 4, the laser scan unit 5, the developing brush 6, the fixing roller 8, and the recording paper transport mechanism 11 have the same configuration. To be connected to the power supply circuit board 12.

  In the laser beam printer 1 at the time of the printing operation, it is necessary to apply a high voltage of about −2000 V to the transfer roller 7 in particular. Therefore, in order to obtain good energization characteristics, the elastic conductive member 30 and the solder pad are generally used. It is necessary to ensure a large contact area. However, when the area (radius) of the land portion formed on the power supply circuit board 12 is simply set so as to correspond to the high voltage, the solder pad formed on the land portion rises high due to the surface tension, resulting in elasticity. On the contrary, the contact area between the conductive member 30 and the solder pad becomes small. Therefore, in the present embodiment, the contact area between the elastic conductive member 30 and the solder pad 45 is increased by forming the land portion 40 as shown below.

  FIG. 4 shows an example of a printed wiring pattern formed on the power supply circuit board 12. FIG. 5 shows the solder pad 45 against which the coil spring portion 30c is abutted. FIG. 6 shows a contact state between the solder pad 45 and the coil spring portion 30c. The power circuit board 12 has a plurality of land portions 40 for supplying power to the transfer roller 7 and the like. Each land part 40 is arrange | positioned in the position facing the coiled spring part 30c of the elastic conduction member 30, as shown in FIG.

  The land portions 40 are arranged in a direction parallel to the dipping direction so that a plurality of first land portions 41 arranged in a direction orthogonal to the dipping direction of the power circuit board 12 and the first land portions 41 are electrically connected to each other. The second land portion 42 provided and the third land portion disposed around the first land portion 41 and connected to the second land portion 42 on the downstream side of the first land portion 41 in the dipping direction. 43 or the like. The dipping direction is the direction in which the solder flows relative to the power circuit board 12 when the power circuit board 12 is immersed in the molten solder bath, that is, the power circuit in the molten solder bath. The direction opposite to the direction in which the substrate 12 is moved in the horizontal direction is assumed. In the present embodiment, the entire contour of the first land portion 41 is formed based on a circle so as to correspond to the coil spring portion 30c, and accordingly, the third land portion 43 is formed in an arc shape. ing. By forming the land portion 40 in such a shape, the land portion 40 can be efficiently disposed in a limited space of the power supply circuit board 12.

  Further, the second land portion 42 is formed thinner than the first land portion 41. Therefore, as shown in FIG. 6, the thickness of the solder pad 45 formed on the surface of the second land portion 42 is thinner than that formed on the surface of the first land portion 41. It does not affect the contact between the solder pad 45 formed on the surface and the coil spring portion 30c. Further, when the power circuit board 12 is pulled up from the molten solder bath, generally, the solder pads 45 of the first land portions 41a on the downstream side among the plurality of first land portions 41 tend to be formed thick. Therefore, in the present embodiment, the third land portion 43 is provided further on the downstream side with respect to the first land portion 41a, whereby excess solder on the first land portion 41a on the downstream side is transferred to the third land portion 43. Spill into. Thereby, the thickness of the solder pad 45 formed on the surface of each first land portion 41 is made uniform, and as shown in FIG. 6, the coil spring portion 30c and the solder pad 45 are brought into contact with each other at a plurality of portions. A large area can be secured.

  As described above, according to the laser beam printer 1 of the present embodiment, the distal end portion of the elastic conducting member 30, that is, the coil spring portion 30 c comes into contact with the solder pad 45 by the elastic force of the torsion coil spring portion 30 b and the coil spring portion 30 c. Since the electrical connection is made, the jumper wire 120 (see FIG. 7), which has been conventionally required, becomes unnecessary, and the transfer roller 7 and the power supply circuit board 12 can be reliably conducted without increasing the number of components. Thereby, the cost of the laser beam printer 1 can be reduced. In addition, since a plurality of the first land portions 41 are arranged in a direction orthogonal to the dipping direction of the power supply circuit board 12, solder with a flat cross section is formed on the surfaces of the first land portions 41 and the second land portions 42. A pad 45 is formed. Here, since the second land portion 42 is formed thinner than the first land portion 41, the thickness of the solder pad 45 on the second land portion 42 is equal to the thickness of the solder pad 45 on the first land portion 41. It becomes thinner than the thickness. As a result, the contact area between the solder pad 45 on the first land portion 41 and the coil spring portion 30c is increased, and conduction between the two is improved. Further, since the third land portion 43 is disposed downstream of the first land portion 43 in the dipping direction of the power circuit board 12, when the power circuit board 12 is pulled up from the molten solder bath, the third land portion 43 is disposed. Excess solder flows into the portion 43, and the thickness of the solder pad 45 formed on the surface of each first land portion 41 is made uniform. Thereby, electrical conduction between the solder pad 45 on the first land portion 41 and the coil spring portion 30c is further improved. Furthermore, since the third land portion 43 is formed so as to surround the first land portion 41, the third land 43 can be formed in a small empty space on the power supply circuit board 12. Not only the degree of freedom of the substrate 12 is increased, but also the laser beam printer 1 can be downsized.

  The present invention is not limited to the configuration of the above-described embodiment, and at least a plurality of first land portions 41 arranged in a direction orthogonal to the dipping direction of the power circuit board 12 and the first land portions 41 are electrically connected to each other. Therefore, the land portion 40 is formed by the second land portion 42 arranged in a direction parallel to the dipping direction, and the solder pad 45 formed on the surface of the land portion 40 and the elastic conductive member 30 are in contact with each other. Any structure may be used as long as it is conductive. The present invention can be modified in various ways. For example, the image forming apparatus is not limited to the laser beam printer 1, and other image forming apparatuses such as a laser beam type copying machine and an ink jet printer are used. Widely applicable to electronic devices. Further, the number and positions of the land portions 40 and the shapes and numbers of the first land portions 41 and the second land portions 42 are not limited to the example shown in FIG.

The figure which shows the structure of the laser beam printer by one Embodiment of this invention. FIG. 3 is a perspective view illustrating a configuration of a transfer roller, a power supply circuit board, and the vicinity thereof in the printer. The perspective view which shows the structure of the elastic conduction member which makes the transfer roller and a power supply circuit board conduct | electrically_connect, and its periphery. The top view which shows an example of the printed wiring pattern formed in the power supply circuit board. The perspective view which shows the shape of the solder pad formed in the land part of the power supply circuit board. The side view which shows the contact state of the solder pad and an elastic conduction member. Sectional drawing which shows the contact state of the jumper line formed in the power supply circuit board of the conventional laser beam printer, and the elastic conduction member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 2 Photosensitive drum 4 Charger (charging means)
5 Laser scan unit (exposure means)
6 Developing brush (Developing means)
7 Transfer roller (transfer means)
8 Fixing roller (fixing means)
9 Paper feed tray 11 Recording paper transport mechanism (transport means)
12 Power Circuit Board 30 Elastic Conducting Member 40 Land Part 41 First Land Part 42 Second Land Part 43 Third Land Part 45 Solder Pad

Claims (3)

A photoreceptor drum having a photoreceptor coated on the surface;
Charging means for uniformly charging the surface of the photosensitive drum;
Exposure means for forming a latent image by irradiating the surface of the photoconductor while scanning with a laser beam;
Developing means for forming a toner image by attaching toner to a portion of the surface of the photoreceptor where a latent image is formed;
At a predetermined transfer position downstream of the developing means in the rotational direction of the photosensitive drum, the photosensitive drum is provided to face the surface of the photosensitive drum, and the surface of the recording sheet is charged to Transfer means for transferring the toner image formed on the surface onto the recording paper;
Fixing means for applying a predetermined heat and pressure to the recording paper on which the toner image has been transferred to fix the toner image on the recording paper;
Conveying means for conveying the recording paper to the transfer position;
An image forming apparatus comprising a power supply circuit board for supplying electric power to the photosensitive drum, charging means, exposure means, developing means, transfer means, fixing means, and conveying means,
In order to electrically connect at least one of the photosensitive drum, charging means, exposure means, developing means, transfer means, fixing means, and conveying means to the power supply circuit board, each means faces the power supply circuit board. An elastic conducting member having elasticity provided over a position;
The power supply circuit board has a land portion that forms a part of the power supply circuit at a position facing the tip of the elastic conducting member,
The land portions are parallel to the dipping direction of the power circuit board so that a plurality of first land portions arranged in a direction orthogonal to the dipping direction of the power circuit board and the first land portions are electrically connected to each other. A second land portion disposed in a direction, and disposed downstream of the first land portion in the dipping direction of the power circuit board and surrounding the first land portion, and is electrically connected to the second land portion. Including the third land portion to be
The second land portion is formed thinner than the first land portion,
Solder pads having a flat cross section are formed on the surfaces of the first land portion and the second land portion, and when the power circuit board is pulled up from the molten solder bath, the solder pad is positioned downstream of the first land portion. The solder flows into the third land portion thus made uniform, the thickness of the solder pad formed on the surface of each first land portion is made uniform,
When the tip of the elastic conducting member is pressed toward the solder pad by the elastic force of the elastic conducting member, when the tip of the elastic conducting member is brought into contact with the solder pad, the contact area is increased, Preventing poor conduction between the tip of the elastic conducting member and the solder pad;
Accordingly, at least one of the photosensitive drum, the charging unit, the exposure unit, the developing unit, the transfer unit, the fixing unit, and the conveying unit can be reliably connected to the power circuit board without increasing the number of parts. An image forming apparatus. In an electronic device equipped with a power circuit board for supplying power,
In order to electrically connect each part of the apparatus and the power supply circuit board, the apparatus further comprises an elastic conductive member having elasticity provided from a position facing the power supply circuit board from each part of the apparatus,
The power circuit board has a plurality of first land parts arranged in a direction orthogonal to the dipping direction of the power circuit board at a position facing the tip of the elastic conducting member, and the first land parts are electrically connected to each other. And a second land portion disposed in a direction parallel to the dipping direction of the power supply circuit board,
Solder pads having a flat cross section are formed on the surfaces of the first land portion and the second land portion,
By the elastic force of the elastic conducting member, the tip of the elastic conducting member is pressed toward the solder pad, and the tip of the elastic conducting member and the solder pad are brought into contact with each other.
Thereby, the electronic apparatus can be reliably connected to each part of the apparatus and the power supply circuit board without increasing the number of parts.   A third land portion disposed around the first land portion and connected to the second land portion on the downstream side in the dipping direction of the power circuit board with respect to the first land portion; When the power circuit board is pulled up from the molten solder bath, the solder flows into the third land portion, whereby the thickness of the solder pad formed on the surface of each first land portion is made uniform. The electronic device according to claim 2.

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