JP2012226166A - Roller positioning mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller positioning mechanism which is capable of positioning a roller by a simple configuration.SOLUTION: The roller positioning mechanism includes a first roller 10, a second roller 20 following the rotation of the first roller 10 to rotate, and a support shaft 30 axially supporting the first roller 10. The first roller 10 axially pierces by the support shaft 30, and the first roller 10 can be attached to and detached from the support shaft 30 by being slid in an axial line direction, and the first roller 10 and the support shaft 30 are provided with a positioning mechanism 40 which positions an axial center of the first roller 10 when the first roller 10 is attached to the support shaft 30.

Description

  The present invention relates to a roller positioning mechanism.

  When a color image is output on a transfer material such as plain paper, yellow, cyan, magenta, and black toner are used. As a specific configuration, there is generally a configuration in which a visible image is formed on four photosensitive drums with toner of each color and transferred in order to obtain a color image. At this time, a visible image of each color is superimposed on the transfer material to create a complementary color.

  In order to obtain a high-quality color image on the transfer material, it is important to accurately overlap the toners of the respective colors. The overlapping accuracy is required to be 40 μm or less. Therefore, it is required that the peripheral speeds of the four color photosensitive drums are the same.

  The reason is that if there is a difference in peripheral speed between the photosensitive drums, it is difficult to slide the visible image formed on the photosensitive drums onto the transfer material. For this reason, Japanese Patent Application Laid-Open No. H10-228667 discloses a configuration for supporting the photosensitive drum.

  Japanese Patent Application Laid-Open No. H10-228561 includes a photosensitive drum portion A, a housing portion B, a photosensitive drum unit C, and an image forming apparatus main body D. The photosensitive drum portion A is formed by a double-cut type photosensitive drum 1 and a photosensitive member supporting member 2 that holds the photosensitive drum 1 from both ends.

  The housing part B includes a cleaning device 9 for cleaning the photosensitive drum 1, a neutralizing device 10 for neutralizing the photosensitive drum 1, and a charging device 11 for charging the photosensitive drum 1. Front and rear flanges 3a and 3b are provided.

  The image forming apparatus main body D is provided with a drive shaft 15 for rotationally driving the photoreceptor A, and accommodates a photoreceptor drum unit C on which the photoreceptor drum portion A is supported.

  With the above configuration, when the photosensitive drum portion A is mounted from the image forming apparatus main body D, the photosensitive drum 1 is temporarily held by the photosensitive drum support member 2 in a temporarily fixed state. Next, the drive shaft 15 is inserted into the slide bearings 7a and 7b provided in the photosensitive drum unit C, and the mounting of the photosensitive drum portion A is completed.

Japanese Patent Laid-Open No. 5-289588

  However, since the configuration shown in Patent Document 1 is complicated, the number of parts increases. In addition, the manufacturing cost increases due to an increase in the number of parts.

  In order to solve the above problem, according to the present invention, in the first aspect of the present invention, a first roller, a second roller that rotates following the rotation of the first roller, and a support shaft that pivotally supports the first roller. The first roller is passed through the support shaft, and the first roller is slid in the axial direction to be detachable from the support shaft. The first roller and the support shaft are mounted with the first roller on the support shaft. In this case, a positioning mechanism for positioning the axis of the first roller is provided.

  According to a second aspect of the present invention, the positioning mechanism is provided on an attachment portion provided on one first roller side that is passed through the support shaft, and on the support shaft that receives the attachment portion when the first roller is attached. It consists of a receiving part, It is characterized by the above-mentioned. The invention of claim 3 is characterized in that transmission means for transmitting the rotation of the first roller to the second roller is provided on both sides of the first roller and the second roller.

  Furthermore, in the invention of claim 4, the transmission means is a first gear provided to the first roller and a second gear provided to the second roller meshing with the first gear, and the first gear and the second gear. Is characterized in that a screw thread is formed in the support shaft direction.

  The invention according to claim 5 is characterized in that the first gear and the second gear are helical gears, and the invention according to claim 6 is characterized in that the first gear is mounted on flanges provided on both sides of the first roller. It is arranged.

  According to the seventh aspect of the present invention, when the first roller is mounted on the support shaft, the first roller is positioned by the positioning action of the shaft center of the first roller of the positioning mechanism and the tooth pressure obtained by meshing the first gear with the second gear. The position of the axial center of the roller is fixed.

  The invention according to claim 8 is characterized in that the support shaft is connected to a drive source for rotating the first roller, and the mounting portion is arranged on the drive source side. The invention according to claim 9 is characterized in that the positioning mechanism has a shape in which the mounting portion is a convex portion provided on the flange, and the receiving portion is fitted to the convex portion.

  According to a tenth aspect of the present invention, the first roller is a photosensitive drum that converts input image data or the like into an optical signal to form an electrostatic latent image on the surface, and the second roller is a static drum formed on the first roller. A developing roller for developing the electrostatic latent image is provided.

  According to a first aspect of the present invention, the first roller and the support shaft are provided with a positioning mechanism for positioning the shaft center of the first roller when the first roller is mounted on the support shaft. The axial center can be positioned.

  According to a second aspect of the present invention, the positioning mechanism includes a mounting portion provided on the side of the first roller that is passed through the support shaft, and a receiving portion provided on the support shaft that receives the mounting portion when the first roller is mounted. With this configuration, the positioning mechanism can be embodied and the axial center of the first roller can be positioned.

  According to a third aspect of the present invention, the rotation of the first roller is transmitted to the second roller by providing transmission means for transmitting the rotation of the first roller to the second roller on both sides of the first roller and the second roller, respectively. it can.

  According to a fourth aspect of the present invention, the transmission means is a first gear provided to the first roller and a second gear provided to the second roller meshing with the first gear, and each gear is a roller By forming helical gears formed in the first gear and the second gear with threads in the support shaft direction, the transmission means is embodied, and the first roller of the first roller and the second gear are embodied. The axial center can be positioned.

  According to a seventh aspect of the present invention, when the first roller is mounted on the support shaft, the first roller is positioned by the positioning action of the first roller of the positioning mechanism and the tooth pressure obtained by meshing the first gear with the second gear. The position of the roller axis can be fixed.

  According to the eighth and ninth aspects of the present invention, the support shaft is connected to a drive source that rotates the first roller, the attachment portion is disposed on the drive source side, and the positioning mechanism is provided on the flange. By positioning the convex portion and the receiving portion into a shape that fits the convex portion, the positioning mechanism can be embodied and the axial center of the first roller can be positioned.

  According to a tenth aspect of the present invention, the first roller is a photosensitive drum that converts input image data or the like into an optical signal to form an electrostatic latent image on the surface, and the second roller is formed on the first roller. By using the developing roller for developing the electrostatic latent image, it can be diverted to an electrophotographic apparatus.

The schematic of the apparatus to which the positioning mechanism of the roller of the present invention is applied. Schematic diagram of the image forming apparatus of FIG. FIG. 3 is a view as seen from an arrow A in FIG. 2, showing a state where a photosensitive drum is attached to and detached from a support shaft. The figure which shows the state which mounted | wore the support shaft from the state of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an apparatus to which the roller positioning mechanism of the present invention is applied.

  In this apparatus, a conveyance path is formed in a substantially vertical direction by two or more conveyance means 1, and two or more image forming apparatuses (2Y, 2M, 2C, 2BK) are arranged at a predetermined interval between the conveyance paths. It is arranged.

  Under this configuration, the transfer material is fed from a paper feeding means (not shown) to the conveyance path, and a toner image is sequentially transferred to the transfer material to form a color image, and then these unfixed color images are placed at predetermined positions. Are fixed together by fixing means 3 arranged in the above.

  The image forming apparatus has a configuration in which yellow Y, magenta M, cyan C, and black BK are sequentially arranged, and each of the image forming apparatuses (2Y, 2M, 2C, 2BK) is provided with the roller positioning mechanism of the present invention. ing. FIG. 2 shows a schematic diagram of the image forming apparatus. The other color image forming apparatuses have the same configuration. The image forming apparatus includes an image forming unit A and a transfer unit B.

  In this embodiment, the roller positioning mechanism of the present invention is shown in FIG. 2 and described with respect to the image forming apparatus. However, the present invention is not limited to this, and a roller support mechanism that is detachable in the axial direction. For example, the present invention may be applied to a roller that supports a belt.

  Next, each part will be briefly described. The image forming unit A includes an image carrier A10, a charge removal device A20, a charging device A30, an exposure device A40, a developing device A50, and a cleaning device A60. These and the transfer portion B are arranged at appropriate positions around the image carrier A10.

  The image carrier A10 is the first roller 10 of the present invention. For example, the image carrier A10 rotates in a direction indicated by an arrow, that is, a counterclockwise direction, and has a configuration in which an electrophotosensitive member A11 is provided on the surface of a drum-like substrate such as aluminum. This is the drum 10. As the photoreceptor A11, a well-known one such as an OPC (organic photoconductor) photoreceptor A11 or an amorphous silicon photoreceptor can be used. Both sides of the photoreceptor A11 are press-fitted by flanges 11. The flange 11 is made of aluminum in order to reduce the weight of the photosensitive drum 10.

  The photosensitive drum 10 is supported by a support shaft 30 and is detachably attached to the support shaft 30 by being slid in an arrow direction (axial direction) by a positioning mechanism 40 described later. As shown in FIG. 2, the support shaft 30 is connected to a drive source 50.

  The static eliminator A20 neutralizes the surface of the image carrier A10 by erasing electric charges remaining on the surface of the image carrier A10, and is specifically an eraser lamp. The charging device A30 uniformly charges the surface of the image carrier A10 neutralized by the neutralization device A20 to a characteristic polarity, and is specifically a corona charger.

  The developing device A50 develops a toner image on the latent image formed on the image carrier A10. Specifically, the toner cartridge A51 filled with toner and the toner supplied from the toner cartridge A51 are accommodated. A developing container A52, a developing roller 20, a layer thickness regulating portion A53 that is arranged in contact with the developing roller 20 at an appropriate pressure, and forms a certain thin toner layer on the developing roller 20, the developing roller 20, A supply roller A54 that is provided in contact with each other and supplies the toner in the developing container A52 to the developing roller 20 and a stirring member A55 disposed behind the supply roller A54 are provided.

  The developing roller 20 corresponds to the second roller 20 of the present invention, and is supported by the developing container A52. The developing roller 20 and the photosensitive drum 10 are provided with transmission means 60 described later, and the rotation of the photosensitive drum 10 is transmitted to the developing roller 20.

  Both sides of the developing roller 20 are press-fitted with flanges 21 in the same manner as the photosensitive drum 10. The flange of the developing roller 20 is formed of a plastic mold. In the following description, the first roller will be described as the photosensitive drum 10 and the second roller as the developing roller 20.

  The transfer unit B transfers the toner image developed on the image carrier A10 onto a sheet. Specifically, the transfer unit B10 transfers the toner image onto the sheet, and the transferred sheet from the image carrier A10. It comprises a separation device B20 for separation.

  The cleaning device A60 collects the toner remaining on the image carrier A10 without being transferred to the paper after the transfer. Although not shown, the fixing device fixes the toner image transferred to the paper, and specifically includes a fixing roller and a pressure roller.

  Next, the positioning mechanism 40 will be described. 3 and 4 are schematic views of a roller positioning mechanism. The positioning mechanism 40 includes an attachment part 41 and a receiving part 42.

  The attachment portion 41 is provided on the side of the developing roller 20 that is passed through the support shaft 30. Specifically, the attachment portion 41 is a convex portion projecting from the center of the flange 11. Furthermore, the receiving part 42 consists of a plastic mold, and is formed in the concave line so that the convex part of the attaching part 41 may fit.

  Further, the receiving portion 42 is disposed at a position where the mounting portion 41 is surely fitted into the receiving portion 42 when the photosensitive drum 10 is mounted, and is fixed to the support shaft 30 by a pin or the like.

  The transmission means 60 includes a first gear 12 and a second gear 22 provided on the flanges (11, 21) of the photosensitive drum 10 and the developing roller 20. A helical gear is formed on the first gear 12 and the second gear 22, and a screw thread is provided in the direction of the support shaft 30.

  With the above configuration, the photosensitive drum 10 is slid in the direction of the arrow through the space between the teeth of the first gear 12 and the second gear 22 from the state where the photosensitive drum 10 is released from the support shaft 30 as shown in FIG. . This sliding is performed until the attachment part 41 fits into the receiving part 42.

  When the mounting portion 41 is fitted into the receiving portion 42, the photosensitive drum 10 is mounted on the support shaft 30 as shown in FIG. At this time, the photosensitive drum 10 is fixed to the support shaft 30 by the fitting of the mounting portion 41 and the receiving portion 42 and the tooth pressure obtained by engaging the first gear 12 with the second gear 22 and the photosensitive drum 10 is The position of the shaft center is fixed.

  As a result, even if a slight axial misalignment occurs mechanically, the misalignment is absorbed between the mounting portion 41 and the receiving portion 42 and by the tooth pressure of the first gear 12 and the second gear 22, The photosensitive drum 10 can be rotated without causing rotation unevenness due to axial blurring.

  In particular, when applied to a color electrophotographic apparatus that forms a color image using toners of four colors of yellow, cyan, magenta, and black as shown in FIG. 1, there is no deviation in the position of the toner image of each color. It is suppressed to a certain extent, and a high-quality image can be obtained.

10 First roller (photosensitive drum)
20 Second roller (developing roller)
30 Support shaft 40 Positioning mechanism

Claims (10)

A first roller, a second roller that rotates following the rotation of the first roller, and a support shaft that pivotally supports the first roller;
The first roller is pivoted through the support shaft, and is detachable from the support shaft by sliding the first roller in the axial direction.
A roller positioning mechanism, wherein the first roller and the support shaft are provided with a positioning mechanism for positioning an axis of the first roller when the first roller is mounted on the support shaft.   The positioning mechanism includes a mounting portion provided on one side of the first roller that is passed through the support shaft, and a receiving portion provided on the support shaft that receives the mounting portion when the first roller is mounted. The roller positioning mechanism according to claim 1, comprising:   2. The roller positioning mechanism according to claim 1, wherein transmission means for transmitting rotation of the first roller to the second roller is provided on both sides of the first roller and the second roller. . The transmission means includes a first gear provided on the first roller and a second gear provided on the second roller meshing with the first gear,
The roller positioning mechanism according to claim 3, wherein the first gear and the second gear are threaded in the direction of the support shaft.   The roller positioning mechanism according to claim 4, wherein the first gear and the second gear are helical gears.   6. The roller positioning mechanism according to claim 4, wherein the first gear is disposed on flanges provided on both sides of the first roller.   When the first roller is mounted on the support shaft, the first roller is caused by the positioning action of the shaft center of the first roller of the positioning mechanism and the tooth pressure obtained by meshing the first gear with the second gear. The roller positioning mechanism according to any one of claims 1 to 6, wherein the position of the axis is fixed. The support shaft is connected to a drive source that rotates the first roller,
The roller positioning mechanism according to claim 2, wherein the attachment portion is disposed on the drive source side.   The roller positioning according to claim 1, wherein the positioning mechanism has a shape in which the mounting portion is a convex portion provided on the flange, and the receiving portion is fitted to the convex portion. mechanism. The first roller is a photosensitive drum that converts input image data or the like into an optical signal to form an electrostatic latent image on the surface,
5. The roller positioning mechanism according to claim 1, wherein the second roller is a developing roller that develops an electrostatic latent image formed on the first roller.

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