JP2008002946A - Rotation information detecting device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily-assembleable/attachable rotation information detecting device capable of arranging highly accurately a detection means to a rotor plate, and an image forming apparatus equipped therewith. <P>SOLUTION: The detecting device includes a slit disk 110 provided on a driving shaft 101 of the image forming apparatus, on which a prescribed slit 121 for detecting rotational speed of the driving shaft 101 is formed; a sensor 113 arranged oppositely to the slit 121 provided on the slit disk 110, for detecting a pattern; and a case member comprising a detection member support member 114 fitted loosely to the driving shaft 101 and a casing member 115 fixed by being fitted to the detection member support member 114, and fixed to a casing 10. The sensor 113 is arranged on a sensor engaging part 114 of the detection member support member 114. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a rotation information forming member provided on a rotation shaft and formed with position information for detecting rotation information of the rotation shaft, and detection means for reading the position information and detecting rotation information of the rotation information formation member. In particular, the present invention relates to a rotation information detection device capable of arranging detection means with high accuracy with respect to a rotation information forming member, and an image forming apparatus including the rotation information detection device.

  In the electrophotographic photosensitive drum driving unit of an image forming apparatus such as a copying machine, a printer, or a facsimile machine that performs image formation, in order to suppress fluctuations in the rotational speed of the photosensitive drum as much as possible, A slit disk is provided as a rotation information detection device on the drive shaft, and the speed control of the drive source is performed based on the detected speed fluctuation data. Such a rotation information detecting device is not limited to the photosensitive drum, but is applied to a rotating member in which fluctuations in rotation speed should be suppressed in the image forming apparatus.

  Further, such a rotation information detection device is not limited to an image forming device, and is provided in various industrial fields to reduce the speed variation of the rotation member. Based on the speed variation data detected by the rotation information detection device, The present invention is applied to an apparatus having a configuration for controlling the speed of a drive source.

  As such a rotation information detection apparatus, there are the following. In Patent Document 1, a rotary member that is formed in a disc shape that fits on a rotary shaft and in which a plurality of detection patterns are arranged along the circumferential direction, and a pattern that reads the detection pattern in a non-contact state with the rotary member. An assembly structure for assembling a slit disk composed of a detection element to the rotation shaft, the rotation member, the pattern detection element, a mounting substrate to which the pattern detection element is fixed, and the rotation member And a cage that is fixed to the mounting substrate so as to cover the annular member, and an annular step is formed at one end in the axial direction of the rotating member, while the cage is loosely fitted to the annular step. A restriction hole is formed, and a predetermined gap is formed on the mounting board between the mounting board and the rotating member, and a restriction protrusion is formed to prevent the annular step portion and the restriction hole from coming off. It is characterized by Assembly structure of a slit circular plate is described.

  In Patent Document 2, a light guide is combined with a rotating plate in which a plurality of slits are formed in the circumferential direction, and light emitted from a signal light emitting element transmitted through the rotating plate is deflected by the light guide to enter the light receiving element. An optical slit disk is described.

  Patent Document 3 discloses a light source means, a disk having a radiation grating on which a light beam from the light source means is incident, a relatively rotating disk, and a radiation grating that transmits modulated light from the radiation grating of the disk. A planar substrate disposed oppositely, a light receiving means for receiving modulated light from a radiation grating of the planar substrate, a light source means, a main body unit for fixing the planar substrate and the light receiving means, and a disk unit for fixing the disk; In a rotational displacement information detecting apparatus for obtaining relative rotational displacement information between the disk and the planar substrate using a signal from the light receiving means, the main body unit and the disk unit are separated, and the disk unit The disk hub for fixing the disk is composed of two parts, and the two parts can be moved relatively in the axial direction. Rotational displacement information detection apparatus is described that.

  Patent Document 4 includes a disk that is mounted on a rotary shaft and is driven to rotate. Marking is performed on the surface in the vicinity of the outer periphery of the disk at an equal pitch. Provided with a gripping part composed of holes or protrusions facing each other across the center of the disk so that it does not come into contact with the marking when it is extracted from the rotating shaft, and has a structure that prevents dust from adhering to the marking Is described.

  Patent Document 5 discloses a rotating body that is rotationally driven by the rotational force of a motor, a plurality of detected portions that are annularly arranged around the rotation axis of the rotating body, a detector that detects the detected portions, A first section having two of the detected parts at both ends and a second section having the detected parts at both ends and at least one end different from the detected section of the first section are set. When the rotating body rotates, the passage time detecting means for detecting the passage time during which the first section and the second section pass through the detector based on the signal from the detector, and the passage time detecting means Amplitude phase generation means for generating the amplitude and phase of the rotation period fluctuation related to the desired period of the rotating body based on the detected transit time, and the rotation period fluctuation is reduced based on the amplitude and phase generated by the amplitude phase generation means Rotation control means for controlling the rotation of the motor It has been described also rotary body drive control device comprising a.

Japanese Patent No. 3171003 JP-A-9-280896 JP-A-10-132611 JP 2005-31080 A JP-A-2005-312262

  By the way, in the above-described electrophotographic image forming apparatus, the surface of the photosensitive member is charged so as to have a uniform potential, and the image portion and the non-image portion are separated based on the image information to be formed, and the photosensitive device is exposed by the exposure device. An electrostatic latent image is formed by exposing the body surface. Toner is attached to the image portion of the electrostatic latent image on the surface of the photoreceptor by a developing device to form a toner image (a visible image). Thereafter, the toner image is transferred to a sheet by a transfer unit, and the toner is melted and fixed on the sheet by passing the sheet through the fixing unit. An image is formed on a sheet by such a process.

  In such a process, various components are driven at a predetermined speed, but it is important that the speed of the photoreceptor surface is constant. If the speed of the surface of the photoreceptor is not constant, the image is stretched and contracted in the exposed area and the transferred area. Although the photoconductor may be in the form of a belt, as shown in the drawing, the photoconductor is often in the form of a drum.

  Particularly, in recent color copying machines and printers, color images are formed with four colors of cyan, magenta, yellow and black, and four photosensitive drums for forming toner images of the respective colors on the image forming path. The method of arranging the two (hereinafter referred to as tandem method) has become the mainstream. There is one photosensitive drum, and four developing devices of each color are arranged around it, and each time a toner image of one color is formed on the photosensitive drum, the toner image is moved onto the intermediate transfer belt. Although there is a method in which the toner images of four colors are transferred to the paper at once after the toner images of four colors are overlaid on the above, in the current color image forming apparatus, from the viewpoint of image formation productivity, The proportion of tandem methods is large.

  When there is a speed variation in each tandem photosensitive drum, there is a problem of “color misalignment” in which different colors are originally formed at portions where the colors should be combined.

  Even when the image is stretched and contracted to the extent that it is difficult to recognize when an image is formed with only one color, “color shift” in which the colors to be combined do not match is easily recognized when the images of four colors are overlapped. Even if the amount of misalignment is such that it is not recognized that it is clearly deviated, it will appear as shading of the image and color unevenness.

  Therefore, it is important to suppress fluctuations in the rotational speed of the photoconductor and drive at a constant speed in order to maintain good image quality.

  As a technique for making the rotation speed of the photosensitive drum constant, a slit disk, which is a disk-shaped member provided with a pattern at regular intervals in the circumferential direction, is provided on the shaft for driving the photosensitive drum, A detection element (sensor) that optically detects the passage of the pattern is provided, and by detecting the passage time of each pattern, the rotational speed of the photosensitive drum drive shaft is detected, and the motor is arranged to cancel the detected speed fluctuation. In general, a method of maintaining the rotational speed of the photosensitive drum constant by controlling a drive source such as the above.

  As a factor of the speed fluctuation generated in the photosensitive member driving shaft, a large-diameter gear is fitted to the photosensitive member driving shaft, and a small-diameter gear provided on the motor shaft is engaged with the large-diameter gear of the photosensitive member driving shaft. In the case of a typical configuration in which the rotational speed is decelerated and the photosensitive member drive shaft is driven, a large amount is caused by a speed fluctuation in one rotation cycle of the motor shaft and a speed fluctuation in one rotation of the photosensitive member shaft. The speed fluctuation in one rotation period of the motor shaft is caused by the eccentricity of the motor shaft or the accumulated pitch error of the gear provided on the motor shaft, and the speed fluctuation of one rotation of the photoreceptor shaft is caused by the eccentricity of the large diameter gear or the cumulative gear. Although it occurs due to a pitch error or the like, suppressing these components has a great effect of reducing the speed fluctuation of the photoreceptor.

  That is, as the number of patterns on the slit disk is larger in the circumferential direction, the resolution is higher and the rotation speed can be detected with higher accuracy. It is possible to reduce the speed fluctuation of the photosensitive drum with an inexpensive configuration by focusing on the speed fluctuation of one rotation cycle of the photosensitive member and the speed fluctuation of one rotation cycle of the motor.

  However, when detecting the rotational speed by such a slit disk configuration, the accuracy of mounting the slit disk and the sensor is important. The pattern forming portion of the slit disk is a disk-like member, and is attached to the drive shaft to be attached via a member provided with a cylindrical member fitted to the shaft and a hook-like member protruding in the circumferential direction. . Ideally, the rotation centers of the shaft and the cylindrical portion and the cylindrical portion and the pattern on the slit disk coincide with each other. Still, the coaxiality between the drive shaft rotation center and the center of the slit disk pattern cannot be reduced to 0, and some eccentricity occurs, but the accuracy deterioration due to the eccentricity uses two detection members (sensors), It is possible to cancel by providing the detection at a symmetrical position with respect to the axis.

  However, it is important that the distances from the rotation centers of the two sensors are as equal as possible, that is, the sensor mounting accuracy. For the sensor mounting accuracy, the positional relationship between the line (optical axis) connecting the centers of the light emitting element and the light receiving element of the sensor, that is, the sensor detection position, and the pattern on the slit disk is important. If the radius of the sensor reading position changes, the reading circumference changes, and consequently the pattern passage time changes, so that the rotational speed is erroneously detected. Therefore, it is necessary to ensure the distance from the center of the drive shaft to the sensor with high accuracy.

  Also, the angle formed by the two sensors with respect to the drive axis is not a problem if it is exactly 180 degrees, but if the angle is shifted by several degrees, an error occurs in the detection of the rotational speed.

  If the accuracy is insufficient and the rotation speed is detected, even if the rotation of the motor is controlled based on the data, there is a difference from the ideal constant rotation speed.

  Further, when assembling the slit disk and the sensor around the photosensitive member axis, there is a problem as described in Patent Document 1. That is, since the detection element (sensor) that reads the detection pattern of the slit disk is disposed so as to straddle the periphery of the disk-shaped slit disk, the rotating member is first fixed to the drive shaft of the photosensitive drum. If this happens, there is a high possibility that the rotating element and the detection element will come into contact when the detection element is fixed to the support frame of the photosensitive drum later, and the detection element is fixed to the support frame first. Therefore, it is impossible to insert the periphery of the rotating member into the detecting means while fitting the rotating member to the drive shaft of the photosensitive drum.

  Therefore, it is very complicated to assemble the slit disk and the detection element with respect to each other while simultaneously fixing the slit disk and the detection element to the drive shaft or the support frame of the photosensitive drum.

  Further, such an encoder assembly work requires a small work space at hand, and the rotating member and the detection element may come into contact with peripheral devices during the assembly work and may be damaged.

  In the one described in Patent Document 1, the sensor is assembled to the mounting board, the encoder is sandwiched between the sensor reading units, the sensor and the encoder are contained in the cage, and the cage is fixed to the mounting board. By assembling them together and then fitting them onto the photosensitive member drive shaft, problems that occur during assembly are reduced and the assembly is improved. However, this configuration is insufficient to maintain the sensor mounting accuracy with respect to the encoder.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotation information detection device that can be easily assembled and assembled and can dispose detection means with high accuracy with respect to a rotating plate, and an image forming apparatus including the rotation information detection device.

  According to a first aspect of the present invention, there is provided a rotation information forming member provided on the rotation shaft and forming position information for detecting rotation information of the rotation shaft, and the position information is read and rotation information of the rotation information forming member is detected. Rotational information detection, comprising: a detecting means for detecting, a detecting base supporting member integrally including a fitting base portion that is fitted to the rotating shaft directly or via a bearing and a supporting portion for supporting the detecting means. Device.

  According to a second aspect of the present invention, in the rotation information detection device according to the first aspect, the detection means supporting member includes a detection means holding portion that engages with the detection means and restricts and holds the position of the detection means. It is characterized by that.

  According to a third aspect of the present invention, in the rotation information detecting device according to the first or second aspect, the detection means supporting member is formed of a synthetic resin containing a polyacetal resin.

  According to a fourth aspect of the present invention, in the rotation information detecting device according to any one of the first to third aspects, the rotation information forming member includes a connecting member coupled to the rotation shaft so as to rotate the rotation information forming member together with the rotation shaft. A gradient is formed in the opening of the attachment hole to the rotation shaft of the connecting member.

  According to a fifth aspect of the present invention, in the rotation information detection device according to any one of the first to fourth aspects, the detection means and the rotation information forming member are combined with the detection means support member in combination with the detection means support member. Including a casing member to enclose, provided with a gap of a predetermined interval between the casing member and the rotating shaft, protruding a part of the connecting member from the gap between the rotating shaft and the casing member, in the protruding portion of the connecting member, The connecting member is fixed to the rotating shaft.

  According to a sixth aspect of the present invention, in the rotation information detecting device according to any one of the first to fifth aspects, the rotation information detecting member or the connecting member in the axial direction is provided on one or both of the detecting means supporting member and the casing member. It is characterized in that a convex portion for regulating the position is provided.

  According to a seventh aspect of the present invention, in the rotation information detecting device according to any one of the first to sixth aspects, the detecting means is a detecting means supporting member or a detecting means supporting member and a casing member from the normal direction of the rotating shaft. It is characterized in that it can be attached to and detached from.

  The invention according to claim 8 is the rotational information detection device according to any one of claims 1 to 7, wherein one or both of the detection means support member and the casing member are formed of a transparent material. .

  The ninth aspect of the present invention is the rotation information detecting device according to any one of the first to eighth aspects, wherein the detecting / supporting signal line coupling portion of the detecting means is provided on the detecting means supporting member or the casing member. It is characterized by.

  A tenth aspect of the present invention is an image forming apparatus comprising the rotation information detecting device according to any one of the first to tenth aspects.

  According to the rotation information detection device of the present invention, since the detection means can be arranged on the detection means support member, there is an effect that the detection means can be easily and highly accurately arranged with respect to the rotation information forming member.

  In addition, according to the image forming apparatus of the present invention, the rotation of the rotating body arranged in the image forming apparatus can be detected with high accuracy, so that the rotation control of the rotating body can be performed with high accuracy and stable. There is an effect that the formed image can be formed.

  Embodiments as the best mode for carrying out the present invention will be described below with reference to the drawings.

  Hereinafter, the configuration of the rotation information detecting apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing the structure of the rotation information detecting device according to the first embodiment, FIG. 2 is an enlarged cross-sectional view showing the structure of the rotation information detecting device shown in FIG. 1, and FIG. 3 is the rotation shown in FIG. It is a disassembled perspective view which shows the structure of an information detection apparatus.

  In this example, the rotation information detection device 100 is attached to a drive shaft 101 that is a rotation shaft for driving the photosensitive drum 1 of the image forming apparatus. The photosensitive drum 1 is supported by an apparatus frame by a drive shaft 101, and the drive shaft 101 is supported by a ball bearing 102 that is a bearing member with respect to a housing 10 that is a base portion of the image forming apparatus main body. .

  In this example, the left end of the drive shaft 101 is not shown, but is supported on the image forming apparatus main body by a ball bearing in the same manner as the right end. In this example, a large-diameter gear 106 is attached to the end of the drive shaft 101, and this large-diameter gear 106 meshes with a pinion gear 104 provided on the drive shaft of the motor 103 that is a drive source. The large-diameter gear 106, the drive shaft 101, and the photosensitive drum 1 are rotationally driven by this rotation. The motor 103 and the pinion gear 104 are arranged on a motor bracket 105 fixed to the housing 10.

  The drive bracket 11 is a support for a member (not shown) that drives an image forming element other than the photosensitive member, and is fixed to the housing of the image forming apparatus main body by screws or the like. The motor bracket 105 that supports the motor 103 is fixed to the housing 10 of the image forming apparatus main body or the drive bracket 11 with screws 130a. In this example, the rotation information detection device 100 is disposed between the drive bracket 11 and the motor bracket 105.

  Hereinafter, the rotation information detection apparatus 100 according to this example will be described. In this example, as shown in FIG. 3, the rotation information detection device 100 includes a slit disk 110 that is a rotation information forming member in a casing 120 that includes a detection means support member 114 and a casing member 115. Rotation information of the drive shaft 101 is detected by detecting the slit 121 formed in the slit disk 110 by a sensor 113 which is a detection means disposed in the casing 120. Is detected.

  In this example, the slit disk 110 having the connecting member 111 and the pressing member 112 attached thereto is assembled in the detection means support member 114, the motor bracket 105 is further attached, and the sensor 113 is connected to the detection means support member 114 and the casing member 115. Assembled to the casing 120 formed in The drive shaft 101 is inserted into the assembled rotation information detecting device 100 and attached to the drive bracket 11 with screws 130a.

  Next, the detection means support member 114 will be described. The detection means support member 114 is made of a synthetic resin with good slidability, such as a POM resin, and can be formed entirely or partially transparent. If the detection means support member 114 is made transparent, it can be performed while checking the position of each member at the time of assembly, so that workability is improved and whether or not there is an abnormality after assembly or during operation is checked. Becomes easier.

  Further, the detection means supporting member 114 is formed with a shaft penetrating portion 114d so that the driving shaft 101 penetrates at a substantially central portion thereof, and the driving shaft 101 is disposed so as to penetrate the shaft penetrating portion 114d. The shaft penetrating portion 114d is formed with a tapered portion 114f that facilitates insertion of the drive shaft 101.

  The detecting means support member 114 is formed with a sensor engaging portion 114a for fitting and fixing the outer shape of the detecting means. By fitting and engaging the sensor 113 with the sensor engaging portion 114a, the sensor 113 can be positioned and fixed, and the sensor 113 can be arranged with high accuracy, and the trouble such as screwing of the sensor 113 can be saved. And the number of parts can be reduced.

  Further, the detection means support member 114 is provided with an annular convex portion 114b toward the slit disk 110 side, and the radial position of the connecting member 111 that supports the slit disk 110 is restricted. The projecting portion 114b and the connecting member 111 have a certain clearance, and the slit disk 110 and the connecting member 111 have a certain margin with respect to the casing member and are held by the casing member in a state where they are held by the driving shaft 101. Fitted.

  In this example, the detection means support member 114 and the drive shaft 101 disposed through the detection means support member 114 are in sliding contact. In this example, the detection means support member 114 is formed of POM resin. For this reason, the sliding resistance between the detection means support member 114 and the drive shaft 101 can be reduced.

  When the image forming speed is high and the rotation of the drive shaft 101 is fast, the detection means support member 114 is configured to interpose the drive shaft via the bearing member, so that an excessive load can be avoided. Specifically, the bearing member may be selected according to the speed of the drive shaft, such as a ball bearing or a sliding bearing.

  Next, the slit disk 110 will be described. The slit disk 110 is attached to the drive shaft 101 by a connecting member 111 and a pressing member 112. The slit disk 110 is a thin metal plate having a disk shape, and is formed with slits 121 at predetermined intervals in the circumferential direction near the outer periphery thereof. In this example, the passage time of each slit 121 is detected by the sensor 113, whereby the rotation speed of the slit disk 110 can be detected. As a result, the rotation speed of the drive shaft 101 and the photosensitive drum 1 is detected. be able to.

  In this example, the slit disk 110 forms the pattern by providing the slit 121 on the metal thin plate, but can be formed by writing the pattern in a color that does not transmit light to the transparent thin plate member.

  In this example, since the slit disk 110 is a thin metal member, the slit disk 110 cannot be directly fixed to the drive shaft 101. Therefore, in this example, the slit disk 110 is fixed to the drive shaft 101 by the connecting member 111.

  Next, the connecting member 111 will be described. In this example, the connecting member 111 includes a cylindrical portion 111a that is fitted to the drive shaft 101 and a flange portion 111b that protrudes in the circumferential direction. The slit disk 110 is configured such that a hole at the center thereof is fitted to the outer periphery of the cylindrical portion 111 a of the connecting member 111 and is fixed between the flange portion 111 b and the pressing member 112.

  In this example, the cylindrical portion 111a protrudes outside the casing member 115 in a state where the casing member 115 is assembled. The protruding cylindrical portion 111a is fixed to the drive shaft 101 with a screw 131. Therefore, after assembling the rotation information detection device 100 by assembling the detection means support member 114, the connection member 111, and the casing member 115, the drive shaft 101 is inserted into the rotation information detection device 100, the screw 131 is tightened, and the connection member 111 is driven. It can be fixed to the shaft 101.

  Here, the pressing member 112 is an annular plate-like member, which prevents the slit disk 110 from floating from the connecting member 111 and maintains the flatness of the slit disk 110. In the present embodiment, the slit disk 110, the flange 111b, and the pressing member 112 are fixed by adhesion, but can be fixed by double-sided tape, thermal welding, screwing, or the like. Further, the connecting member 111 is formed with a tapered portion 111c that is expanded outward in order to facilitate the insertion of the connecting member 111 into the drive shaft 101.

  Next, the sensor 113 will be described. The sensor 113 optically detects a pattern. In this embodiment, the sensor 113 includes a light emitting element and a light receiving element, and detects a passage of an object depending on whether or not the light is shielded between them. A sensor. In the transmissive sensor as in this example, it is necessary to arrange the light emitting unit and the light receiving unit in a positional relationship such that the slit disk pattern is sandwiched between them.

  In this example, a signal line 113a is connected to the sensor 113, and a signal from the sensor 113 is extracted to the outside.

  In the present embodiment, two sensors 113 are provided at symmetrical positions across the drive shaft rotation center in order to cancel out a detection error due to the eccentric mounting of the slit disk 110. As described above, the sensor 113 is disposed on the sensor engaging portion 114a of the detection means support member 114, and is fixed by covering the casing member 115. In addition, about a sensor, the reflection type sensor in which a light emitting element and a light receiving element can be located in the same direction with respect to a detection pattern can be used.

  Here, in such a rotation information detecting device 100, it is desirable that the rotation center of the pattern by the slit 121 formed in the circumferential direction on the slit disk 110 and the coaxiality of the drive axis coincide as much as possible. For each of the members 101, the connecting member 111, and the slit disk 110, it is necessary to manage the dimensions that affect the coaxiality.

  Next, the casing member 115 will be described. The casing member 115 is assembled with the detection means support member 114 so as to cover the slit disk 110 and the sensor 113 after the slit disk 110 and the sensor 113 are set on the detection means support member 114. The casing member 115 is made of a synthetic resin having good slidability, for example, a POM resin, and can be formed entirely or partially transparent. If the casing member 115 is made transparent, it can be performed while checking the position of each member at the time of assembly, so that workability is improved and it is easy to check whether there is an abnormality after assembly or during operation. become.

  Further, the casing member 115 is provided with an annular convex portion 115a toward the slit disk 110 side, and restricts the position of the connecting member 111 that supports the slit disk 110 in the radial direction. The protrusion 115a and the presser member 112 have a certain gap, and the slit disk 110, the connecting member 111, and the presser member 112 have some backlash with respect to the casing member and are held by the casing member. The drive shaft 101 is fitted. In addition, when the convex part 115a provided in the casing member 115 slides with the presser member 112, it is desirable that the presser member 112 be made of a material having good slidability.

  Further, the casing member 115 is formed with a shaft penetrating portion 115b at a substantially central portion thereof so that the cylindrical portion 111a of the connecting member 111 passes therethrough.

  As described above, according to the rotation information detection apparatus 100 according to this example, the assembly and rotation of the detection means support member 114, the casing member 115, the slit disk 110, and the sensor 113 are performed before the assembly to the drive shaft 101. What is necessary is just to assemble the information detection apparatus 100. FIG. Then, the assembled 100 is fitted to the drive bracket 11 while being fitted to the drive shaft 101. Then, the cylindrical portion 111 a protruding from the casing member 115 of the rotation information detecting device 100 may be attached to the drive shaft 101. For this reason, workability | operativity can be made favorable rather than the case where the member which comprises the rotation information detection apparatus 100 is assembled | attached around a drive shaft separately.

  When the drive shaft 101 is inserted into the rotation information detecting device 100, the shaft penetrating portion 114d of the detecting means support member 114 is formed with the tapered portion 114f, and the connecting member 111 is formed with the tapered portion 111c. Can be easily arranged in the rotation information detecting apparatus 100.

  Further, the light receiving portion of the sensor 113 can be disposed at an accurate position with respect to the slit disk 110 disposed in the sensor engaging portion 114a of the detection means support member 114.

  Next, a second embodiment of the rotation information detecting apparatus according to the present invention will be described. FIG. 4 is a perspective view showing a second embodiment of the rotation information detecting apparatus according to this example. In this example, the sensor engaging portion 114a can be inserted and fixed from the normal direction of the slit disk 110 after the detection means support member 114, the slit disk 110, and the casing member 115 are assembled. It is a thing. According to this example, the assembly of the detection means support member 114 and the casing member 115 and the attachment of the sensor 113 are facilitated, and the assembly of the rotation information detection device 100 is further improved.

  Next, a third embodiment of the rotation information detecting apparatus according to the present invention will be described. FIG. 5 is a sectional view showing a rotation information detecting apparatus according to the third embodiment.

  In this example, the rotation information detecting device 100 is directly fixed to the housing 10 of the image forming apparatus main body with screws 130b. In this example, the detection means support member 114 is disposed so as to be fitted to the ball bearing 102 installed in the housing 10 of the image forming apparatus. Further, in this example, the sensor 113 is provided with a socket 113c to which a connector 113b disposed at the end of the signal line 113a is connected, in the sensor 113 itself or in the immediate vicinity of the sensor 113.

  According to this example, the sensor 113 and the signal line 113a can be easily separated and connected. After the rotation information detecting apparatus 100 is assembled to the image forming apparatus main body, the signal lines from the image forming apparatus main body are connected. Since the connection is completed by connecting the connector 113b to the socket 113c arranged on the surface of the rotation information detecting device, the signal line 113a does not protrude from the rotation information detecting device 100, and the assembly of the rotation information detecting device 100 is further improved. It will be good.

It is sectional drawing which shows the structure of the rotation information detection apparatus which concerns on a 1st Example. It is an expanded sectional view which shows the structure of the rotation information detection apparatus shown in FIG. It is a disassembled perspective view which shows the structure of the rotation information detection apparatus shown in FIG. It is a perspective view which shows the external appearance of the rotation information detection apparatus which concerns on a 2nd Example. It is sectional drawing which shows the structure of the rotation information detection apparatus which concerns on a 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 10 ... Housing 11 ... Drive bracket 100 ... Rotation information detection apparatus 101 ... Drive shaft (rotation shaft)
102 ... Ball bearing (bearing)
DESCRIPTION OF SYMBOLS 103 ... Motor 104 ... Pinion gear 105 ... Motor bracket 106 ... Large diameter gear 110 ... Slit disk (rotary plate)
111 ... connecting member 111a ... cylindrical part 111b ... collar part 111c ... taper part 112 ... pressing member 113 ... sensor (detection means)
113a ... Signal line 113b ... Connector 114 ... Detection means support member 114a ... Sensor engaging part 114b ... Convex part 114d ... Shaft penetration part 114f ... Tapered part 115 ... Casing member 115a ... convex part 115b ... shaft penetration part 120 ... casing (case member)
121 ... Slits 130a, 130b ... Screw 131 ... Screw

Claims (10)

A rotation information forming member provided on the rotation shaft and forming position information for detecting rotation information of the rotation shaft;
Detection means for reading the position information and detecting rotation information of the rotation information forming member;
A detecting means supporting member integrally comprising a fitting base portion that fits directly or via a bearing on the rotating shaft and a supporting portion that supports the detecting means;
A rotation information detecting device comprising:   2. The rotation information detecting device according to claim 1, wherein the detecting means supporting member includes a detecting means holding portion that engages with the detecting means and restricts and holds the position of the detecting means.   The rotation information detection device according to claim 1 or 2, wherein the detection means support member is made of a synthetic resin containing a polyacetal resin. The rotation information forming member includes a connecting member that couples the rotation information forming member to the rotation shaft to rotate with the rotation shaft,
The rotation information detecting device according to any one of claims 1 to 3, wherein a gradient is formed in an opening portion of the attachment hole to the rotation shaft of the connecting member. A casing member that is combined with the detection means support member and encloses the detection means and the rotation information forming member between the detection means support member,
A gap having a predetermined interval is provided between the casing member and the rotating shaft, and a part of the connecting member is protruded from the gap between the rotating shaft and the casing member.
The rotation information detecting device according to any one of claims 1 to 4, wherein the connecting member is fixed to the rotating shaft at a protruding portion of the connecting member.   6. A convex portion for restricting the axial position of the rotated information detecting member or the connecting member is provided on one or both of the detecting means supporting member and the casing member. Rotation information detection device.   The rotation information detection device according to any one of claims 1 to 6, wherein the detection means is detachably attached to the detection means support member or the detection means support member and the casing member from the normal direction of the rotation shaft. . 8. The rotation information detecting device according to claim 1, wherein one or both of the detecting means supporting member and the casing member are made of a transparent material.   9. The rotation information detection device according to claim 1, wherein a coupling portion of the input / output signal line of the detection means is provided on a detection means support member or a casing member. An image forming apparatus comprising the rotation information detecting device according to claim 1.