JP6729176B2 - Torque detector and image forming apparatus - Google Patents

Description

The present invention relates to a torque detection device and an image forming apparatus.

2. Description of the Related Art Conventionally, there is a torque detection device that uses a drive motor as a drive source for rotationally driving a drive target and detects a drive torque of the drive target by detecting a current flowing through the drive motor. As a technique related to such a torque detection device, for example, those disclosed in Patent Documents 1 to 3 have been already proposed.

Patent Document 1 discloses a developing device that develops a toner image by adhering toner to an electrostatic latent image formed on the surface of an image carrier, and a transfer residual toner remaining on the surface of the image carrier after transferring the toner image. In an image forming apparatus provided with a cleaning device for removing and collecting, when a recycling means for carrying the collected toner collected by the cleaning device to the developing device side, and a carrying load of the recycling means is larger than a predetermined load. , And an overload detecting means for detecting the overload state.

Patent Document 2 discloses a developer container that contains a developer, a developing unit that visualizes a latent image formed on an image bearing member using the developer, and a developer that is contained in the developer container. In an image forming apparatus having a developer transport member for transporting or agitating toner, a driving force transmission unit for transmitting a drive force for rotating the developer transport member, and a rotation speed of the developer transport member. The developer transport member swings in response to a change in load resistance due to the developer when entering the stored developer and when exiting from the stored developer, and the swinging thereof is performed. The amount of developer in the developer container is sequentially detected by detecting the change in the rotation speed caused by the detecting means.

Patent Document 3 discloses a collection container that receives and stores the developer collected from the image carrier, a stirring member that stirs the developer in the collection container, and two shafts that transmit a rotational force to the stirring member. A torque limiter for connecting or disconnecting between the shafts and a full-judgment unit for detecting a shut-off condition between the shafts and judging whether the recovery container is full of developer based on the detected shut-off condition. And a torque limiter for urging and moving one of the cams, which are engaged with each other, provided on each of the shafts and one of the cams. And a spring that connects the shafts to each other, the spring being provided on the one cam and rotating on the one cam with the first rotating member that rotates with the one cam. It is provided between the second rotating member which is positioned along the provided axis and rotates together with the one cam.

JP, 10-254318, A JP-A-11-84850 JP 2012-8381 A

An object of the present invention is to improve the degree of freedom of the torque detection position as compared with the case where the current flowing in the drive source is detected to detect the torque.

Another object of the present invention is to improve the torque detection accuracy as compared with the case where the current flowing in the drive source is detected to detect the torque.

The invention described in claim 1 is a first rotating body arranged on an input side of a rotational driving force,
A second rotating body which is provided coaxially and rotatably with respect to the first rotating body and is arranged on the output side of the rotational driving force;
An elastic member that is integrally formed with the first rotating body and that applies an elastic force along the rotation direction between the first rotating body and the second rotating body,
Detection means for detecting a phase difference in rotation angle between the first rotating body and the second rotating body;
Equipped with
It is a torque detection device that detects torque based on a phase difference in rotation angle between the first rotating body and the second rotating body detected by the detecting means.

According to a second aspect of the present invention, the detection means optically includes first and second rotation angle detection units provided in a fan shape on the first rotary body and the second rotary body, respectively. The torque detection device according to claim 1, wherein a phase difference in rotation angle between the first rotating body and the second rotating body is detected by detecting the phase difference.

According to a third aspect of the present invention, the elastic member is arranged on a rotation shaft of the first rotating body or the second rotating body, one end of the elastic member is the first rotating body, and the other end of the elastic member is the rotating shaft of the first rotating body. The torque detection device according to claim 1, wherein the torque detection device is formed of a torsion spring locked to each of the second rotating bodies.

The invention described in claim 4 is an image forming unit that is rotationally driven by a drive source,
A torque detecting unit arranged between the drive source and the image forming unit, for detecting a load torque acting on the image forming unit;
Equipped with
An image forming apparatus using the torque detecting device according to any one of claims 1 to 3 as the torque detecting means.

According to the invention described in claim 1, the degree of freedom of the torque detection position can be improved as compared with the case of detecting the torque by detecting the current flowing through the drive source.

According to the invention described in claim 1, the torque detection accuracy can be improved as compared with the case where the current flowing through the drive source is detected to detect the torque.
Further, according to the invention described in claim 1, the number of parts can be reduced as compared with the case where the elastic member is formed separately from the first rotating body.

According to the invention described in claim 2, the detecting means optically includes the first and second rotation angle detecting portions provided in the first rotating body and the second rotating body in fan shapes, respectively. Of the first rotating body and the second rotating body with a simple structure, as compared with the case where the phase difference of the rotation angle between the first rotating body and the second rotating body is not detected by the automatic detection. The phase difference of the rotation angle with the rotating body can be detected.

According to the invention described in claim 3, one end of the elastic member is not a torsion spring, and the other end is a torsion spring locked to the second rotary member. The elastic member can be downsized as compared with the case.

According to the invention described in claim 4, the degree of freedom of the torque detection position can be improved as compared with the case where the torque detection device according to any one of claims 1 to 3 is not used as the torque detection means. Therefore, it is possible to easily cope with the torque fluctuation of the image forming unit.

1 is a perspective view showing a torque detection device according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view showing the torque detection device according to the first embodiment of the present invention. FIG. 3A is a perspective view showing the front surface of the first rotating body, and FIG. 3B is a perspective view showing the back surface of the first rotating body. FIG. 7A is a perspective view showing the front surface of the second rotating body, and FIG. 7B is a perspective view showing the back surface of the second rotating body. FIG. 3 is a plan view showing a torque detection device according to a first embodiment of the present invention. It is the EE line arrow line view of FIG. It is a perspective view which shows a torsion spring. It is a perspective view which shows an optical sensor. FIGS. 9A and 9B are explanatory diagrams showing the operation of the torque detection device according to the first embodiment of the present invention, respectively. It is a schematic diagram which shows the principle of the torque detection apparatus which concerns on reference embodiment 1 of this invention. (A), (b) and (c) of FIG. 1 are schematic diagrams respectively showing the principle of the torque detection device according to the first embodiment of the present invention. It is a schematic diagram which shows the principle of the torque detection apparatus which concerns on reference embodiment 1 of this invention. 3 is a graph showing the principle of the torque detection device according to the first embodiment of the present invention. It is a graph which shows the exposure time of an optical sensor, and the relationship of the load torque T. 6 is a graph showing the relationship between the angle θ of the first and second rotation angle detectors and the load torque T. Is a structural view showing an image forming apparatus including a torque detection device according to a second reference embodiment of the present invention. Is a structural view showing an image forming unit of an image forming apparatus of the torque detecting apparatus according to a second reference embodiment of the present invention. It is a block diagram which shows a driving force transmission device. FIG. 9 is a perspective configuration diagram showing a torque detection device according to a second embodiment of the present invention. It is a block diagram showing a driving force transmission apparatus according to the torque detection location according to a third reference embodiment of the present invention. FIG. 9 is a perspective configuration diagram showing a torque detection device according to a third embodiment of the present invention. FIG. 3 is a perspective configuration diagram showing a torque detection device according to the first embodiment of the present invention. FIG. 3 is a perspective configuration diagram showing a torque detection device according to the first embodiment of the present invention. FIG. 3 is a perspective configuration diagram showing a torque detection device according to the first embodiment of the present invention. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 4 of this invention.

Embodiments of the present invention will be described below with reference to the drawings.

[ Reference Embodiment 1]
Figures 1 and 2 show a torque detecting apparatus according to the first reference embodiment. FIG. 1 shows the entire torque detection device, and FIG. 2 shows a state in which constituent members of the torque detection device are disassembled.

As shown in FIG. 1 and FIG. 2, the torque detection device 100 is roughly classified into a first rotating body 101 arranged on the input side of the rotational driving force and a coaxial body with respect to the first rotating body 101. An elastic force is applied between the first rotating body 101 and the second rotating body 102, which is rotatably provided and arranged on the output side of the rotational driving force, and between the first rotating body 101 and the second rotating body 102. A torsion spring 103 (see FIG. 2) that is an example of an elastic member that is made to transmit, and a transmissive type that is an example of a detection unit that detects a phase difference in rotation angle between the first rotating body 101 and the second rotating body 102. The optical sensor 104 of FIG. The first rotary body 101 and the second rotary body 102 are rotatably supported by a rotary shaft 105, respectively.

As shown in FIG. 3, the first rotating body 101 has a columnar supporting portion 112 formed in a cylindrical shape having an insertion hole 111 into which the rotating shaft 105 is inserted, and the shaft supporting portion 112 having the shaft supporting portion 112 on one side thereof. A disk part 113 formed in a disk shape having an outer diameter (diameter) larger than that of the support part 112, and formed so as to form a part of a cylindrical shape in an upright state along the axial direction at the outer peripheral end of the disk part 113. The formed flange portion 114 and the outer peripheral surface of the tip along the axial direction of the flange portion 114 are fan-shaped so as to form a required center angle β smaller than the center angle α of the flange portion 114 toward the outer side in the radial direction. It integrally has the formed rotation angle detection unit 115. Further, at the center of the disc portion 113, an insertion hole 111 of the shaft support portion 112 is provided so as to penetrate therethrough, and a cylindrical mounting portion 116 for mounting the torsion spring 103 is provided along the flange along the axial direction. It is provided so as to have the same height (length) as the portion 114. Further, in the flange portion 114, a locking groove 117 for locking the linearly formed one end portion 131a of the torsion spring 103 is provided at a position corresponding to the one end portion 115b of the rotation angle detection unit 115. It is formed to a depth reaching the surface of the portion 113. The first rotating body 101 is rotatably attached to the rotating shaft 105. The first rotating body 101 may be configured as a simple rotating body, but may be configured as a gear in which teeth such as spur teeth are formed on the outer periphery of the shaft support portion 112 to transmit the rotational driving force. The first rotating body 101 is integrally formed by injection molding of synthetic resin or the like. When a large torque acts on the first rotating body 101, the first rotating body 101 may be integrally formed of metal or the like instead of synthetic resin.

The rotation angle detection unit 115 of the first rotating body 101 detects the rotation angle of the first rotating body 101 by blocking the light from the transmissive optical sensor 104. However, the rotation angle of the first rotating body 101 does not mean an absolute angle with respect to a certain position, but a difference in rotation angle from the second rotating body 102, that is, the first rotating body 101. And the rotation angle of the second rotating body 102 is detected as a phase difference. Usually, one end 115a of the rotation angle detection unit 115 formed in the fan shape of the first rotating body 101 along the rotation direction (circumferential direction) is detected by the optical sensor 104. In the first rotating body 101, the one end 131a of the torsion spring 103 is locked to the other end 115b of the rotation angle detector 115, and the other end 115b of the rotation angle detector 115 is locked. Is the point of action of the rotational force.

On the other hand, as shown in FIG. 4, the second rotating body 102 has a columnar support portion 122 formed in a cylindrical shape having an insertion hole 121 into which the rotation shaft 105 is inserted, and one side surface of the shaft support portion 122. The second rotation angle detection unit 123, which is formed in a fan shape so as to form the required center angle γ toward the outside in the radial direction, faces the outer surface of the second rotation angle detection unit 123 with a required gap. And a pair of locking protrusions 124 and 125 for locking the other linear end portion 131b of the torsion spring 103. Further, the circular arc portion 126 having a small outer diameter formed in the opening portion of the second rotation angle detection portion 123 is configured to have the same outer diameter as the disc portion 113 of the first rotating body 101, for example. It As shown in FIGS. 5 and 6, the pair of locking protrusions 124 and 125 are arranged such that the outer peripheral surfaces thereof coincide with the outer periphery of the flange portion 114 of the first rotating body 101. The second rotating body 102 is rotatably attached to the rotating shaft 105. The second rotary body 102 may be configured as a simple rotary body, but the shaft support portion 122 may be configured as a gear having teeth such as spur teeth formed on the outer periphery to transmit the rotational driving force. The second rotating body 102 is also integrally formed by injection molding of synthetic resin or the like. Also, like the first rotary body 101, the second rotary body 102 may be integrally formed of metal or the like instead of synthetic resin when a large torque is applied.

The rotation angle detection unit 123 of the second rotating body 102 blocks the light from the optical sensor 104 in the same manner as the rotation angle detecting unit 115 of the first rotating body 101, so that The rotation angle is detected. However, the rotation angle of the second rotating body 102 does not detect an absolute angle with respect to a certain position, but a difference in rotation angle from the first rotating body 101, that is, the second rotating body 102. And the phase difference of the rotation angle of the first rotating body 101 is detected. Usually, one end 123a of the rotation angle detection unit 123 formed in the fan shape of the second rotating body 102 along the rotation direction (circumferential direction) is detected by the optical sensor 104. The rotation angle detection unit 123 of the second rotation body 102 is formed in a fan shape having a central angle γ (for example, 180 degrees or more) larger than the central angle β of the rotation angle detection unit 115 of the first rotation body 101. ing. In the second rotating body 102, the other end 131b of the torsion spring 103 is locked near the other end 123a of the rotation angle detector 123, and the other end of the rotation angle detector 123 is locked. The vicinity of 123b is an action point where the rotational force acts.

As shown in FIG. 1, the first rotating body 101 and the second rotating body 102 are arranged in a state in which the first rotation angle detection unit 115 and the second rotation angle detection unit 123 overlap each other. The first rotating body 101 and the second rotating body 102 initially have an edge 115a and an edge 123a of the second rotation angle detector 123 in a state where no torque acts between them. They are combined so as to form a gap having a predetermined angle θ ₀ therebetween. That is, in the torsion spring 103, one end 131 a of the torsion spring 103 is locked in the groove 117 of the first rotating body 101 in the free state where no torque is applied, and The end portion 131b is locked between the pair of locking projections 124, 125 of the second rotating body 102, and the end edge 115a of the first rotation angle detecting unit 115 and the second rotation angle detecting unit 123 are locked. A gap having a predetermined angle θ ₀ is formed between the end edge 123a and the end edge 123a.

As shown in FIG. 7, the torsion spring 103 is an annular portion 131c formed by winding a metal elastic wire rod 131 having a required rectangular or circular cross-sectional shape in an annular shape a required number of times along the axial direction. And has both ends 131a and 131b of the elastic wire rod 131 extending in the tangential direction of the annular portion 131c. The torsion spring 103 adjusts the cross-sectional shape and thickness of the metal elastic wire rod 131, the diameter of the annular portion 131c, the number of windings, and the like, so that the first and second rotating bodies 101 and 102 have The elastic force (torsional rigidity) along the rotation direction is set to a predetermined value. The one end portion 131b of the elastic wire 131 is formed longer than the other end portion 131a.

As shown in FIGS. 1 and 2, the first and second rotating bodies 101 and 102 are mounted on the first rotating body 101 by inserting the rotating shaft 105 into the insertion hole 111 of the first rotating body 101. The annular portion 131c of the torsion spring 103 is inserted into the portion 116, and the one end 131a of the torsion spring 103 is locked in the locking groove 117. In addition, the second rotating body 102 has an insertion hole 121 on the rotating shaft 105 so that the rotating angle detecting section 115 of the first rotating body 101 and the rotating angle detecting section 123 of the second rotating body 102 overlap each other. Is installed through. The other end 131b of the torsion spring 103 is locked to the pair of locking projections 124 and 125 (see FIG. 6) of the second rotating body 102. Incidentally, a rotational driving force is applied to the first and second rotating bodies 101 and 102 in the counterclockwise direction along the arrow direction in FIG.

Further, the optical sensor 104 includes a sensor main body 151 formed in an elongated rectangular parallelepiped shape, as shown in FIG. On one side surface of the sensor body 151, a pair of facing portions 152, 153 are provided to face each other so as to sandwich the rotation angle detecting portions 115, 123 of the first and second rotating bodies 101, 102. .. A light emitting element such as an LED (not shown) is built in one of the facing portions 152. Further, a light receiving element such as a photodiode (not shown) is built in the other facing portion 153. The optical sensor 104 receives the light emitted from the light emitting element built in the one facing portion 152 by the light receiving element built in the other facing portion 153, so that the first and second rotating bodies 101, The rotation angle detection units 115 and 123 of 102 are detected. In the figure, reference numerals 154 and 155 denote attachment portions for attaching the sensor main body 151 to a housing (not shown) of the torque detection device 100, and 156 denotes a socket portion for connecting a cable to the optical sensor 104. As shown in FIG. 1, the output signal from the optical sensor 104 is a control as an example of a calculation unit including a CPU for calculating and detecting torque via a cable (not shown) connected to the socket 156. Sent to circuit 200.

<Detection principle of torque detection device>
In the torque detection device 100, as shown in FIG. 1, the rotational driving force of a drive motor as a drive source (not shown) is input to the first rotating body 101, and the rotational driving force input to the first rotating body 101 is input. Is transmitted to the second rotating body 102 via the torsion spring 103, and the rotational driving force is output from the second rotating body 102 to the load.

At that time, in the torque detection device 100, the first rotating body 101 and the second rotating body 102 are coaxially and rotatably provided with respect to the rotating shaft 105, and the first rotating body 101 and the second rotating body 101 are provided. An elastic force (torsional rigidity) along the rotation direction is applied between the rotating body 102 and the rotating body 102 by the torsion spring 103.

As shown in FIG. 9, when the torque detection device 100 rotationally drives the first rotating body 101, the torque detecting device 100 applies a rotational driving force to the second rotating body 102 in a state in which torsional rigidity acts via the torsion spring 103. Is transmitted. At this time, an elastic force corresponding to the torque T of the load acts on the torsion spring 103 of the torque detection device 100, and the second rotating body 102 applies the load torque T to the first rotating body 101. The driven rotation is delayed by the phase difference of the rotation angle determined accordingly.

FIG. 10 is a configuration diagram schematically showing the torque detection device 100. As shown in FIGS. 10 and 11A, the torque detection device 100 includes the first rotating body 101 in a state where no torque acts between the first rotating body 101 and the second rotating body 102. The required phase difference θ ₀ (=θ) is initially set between the rotation angle detection unit 115 and the rotation angle detection unit 123 of the second rotating body 102.

Now, let T be the load torque, ω be the rotational angular velocity of the first rotating body 101 during steady rotation, k be the torsional rigidity of the torsion spring 103, and be the phase of the rotation angle detecting unit 115 of the first rotating body 101. θ _in , the phase of the rotation angle detection unit 123 of the second rotary body 102 are θ _out , the first rotation angle detection unit 115 of the first rotary body 101 and the second rotation angle detection of the second rotary body 102. The angle formed by the portion 123 is θ, the initial gap between the rotation angle detection unit 115 of the first rotary body 101 and the rotation angle detection unit 123 of the second rotary body 102 is θ ₀ , and the first gap detected by the optical sensor 104 is When the exposure time in the gap between the rotation angle detection unit 115 of the first rotary body 101 and the rotation angle detection unit 123 of the second rotary body 102 is t, the following relational expression shown in [Equation 1] is established.

9A and 9B and FIG. 11B and FIG. 11C show the rotation angle detection unit 115 of the first rotating body 101 and the rotation angle of the second rotating body 102 according to the magnitude of the load torque T. The angle θ formed by the detection unit 123, that is, the phase difference is different. As the load torque T (T2>T1) increases, the rotation angle difference θ (phase difference) between the rotation angle detection unit 115 of the first rotating body 101 and the rotation angle detection unit 123 of the second rotating body 102 is increased. ) Increases (θ2>θ1).

Therefore, the gap (difference in rotation angle θ) between the rotation angle detection unit 115 of the first rotation body 101 and the rotation angle detection unit 123 of the second rotation body 102 should be detected by the exposure time t of the optical sensor 104. Thus, the magnitude of the load torque T acting on the load side is calculated by the control circuit 200 based on the following equation, which is the relational expression shown in [Equation 1].
T=k(ωt−θ ₀ )

As shown in FIGS. 12 to 14, the control circuit 200 detects the load torque T by calculation based on the signal corresponding to the exposure time t output from the optical sensor 104 by the relational expression shown in Expression 1. In the relational expression shown in Formula 1, the rotation speed ω is shown as a known value.

When the rotation speed ω has an unknown value, the control circuit 200 detects the rising cycle of the signal corresponding to the exposure time t output from the optical sensor 104, so that the rotation speed ω is the rising cycle of the signal. It is calculated as the reciprocal of. Therefore, in the torque detection device 100 according to the present embodiment, the rotational speed ω is obtained from the rising cycle of the signal even when the rotational speed ω has an unknown value.

Further, as shown in FIG. 15, when the rotation speed ω has a known value, the control circuit 200 obtains the angle θ based on the signal corresponding to the exposure time t output from the optical sensor 104,
The load torque T may be calculated based on the angle θ.

As described above, in the torque detection device 100 according to the reference embodiment , it is not necessary to detect the current flowing in the drive source as compared with the case where the current flowing in the drive source is detected to detect the torque. The torque can be detected at any position transmitted by, and the degree of freedom of the torque detection position can be improved.

Further, in the torque detection device 100 according to the above-described reference embodiment , it is not necessary to detect the current flowing in the drive source as compared with the case where the current flowing in the drive source is detected to detect the torque. It is less susceptible to electrical noise as in the case of detection, and the phase difference between the rotation angles of the rotating bodies 101 and 102 can be accurately detected by the optical sensor 104, thus improving the torque detection accuracy. be able to.

[ Reference Embodiment 2]
16 and 17 shows an image forming apparatus including a torque detection device according to a second reference embodiment. 16 shows the entire image forming apparatus, and FIG. 17 shows the image forming section of the image forming apparatus.

The image forming apparatus 1 to which the torque detection device according to the second embodiment is applied is configured as a color printer, for example. The image forming apparatus 1 includes a plurality of image forming devices 10 as an example of an image forming unit that forms a toner image developed with the toner forming the developer 4, and a toner image formed by each image forming device 10. An intermediate transfer device 20 that holds each of them and finally conveys them to a secondary transfer position where they are secondarily transferred to a recording sheet 5 as an example of a recording medium, and required recording to be supplied to the secondary transfer position of the intermediate transfer device 20. A sheet feeding device 50 that accommodates and conveys the sheet 5 and a fixing device 40 that fixes the toner image on the recording sheet 5 secondarily transferred by the intermediate transfer device 20 are provided. In addition, reference numeral 1a in the drawing denotes a main body of the image forming apparatus 1, and the main body 1a is formed of a support structure member, an outer cover, and the like.

The image forming device 10 includes four image forming devices 10Y, 10M, 10C, and 10K that exclusively form toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively. It is configured. These four image forming devices 10 (Y, M, C, K) are arranged so as to be arranged in one line in a tilted state in the internal space of the main body 1a. The four image forming devices 10 (Y, M, C, K) are relatively high because the yellow (Y) image forming device 10Y is located above in the vertical direction, and the black (K) image forming device 10 is relatively high. It is in a position where 10K is relatively low.

As shown in FIGS. 16 and 17, each of the yellow (Y), magenta (M), cyan (C), and black (K) image forming devices 10 (Y, M, C, K) has an electrostatic latent image. A rotating photosensitive drum 11 is provided as an example of an image holding member that holds an image, and the following respective devices as an example of toner image forming means are mainly arranged around the photosensitive drum 11. ing. The main devices include a charging device 12 that charges a peripheral surface (image holding surface) of the photosensitive drum 11 on which an image can be formed to a required electric potential, and image information on the charged peripheral surface of the photosensitive drum 11 ( An exposure device 13 as an example of an electrostatic latent image forming unit that irradiates light based on a signal) to form an electrostatic latent image having a potential difference (for each color), and the electrostatic latent image corresponding to a color (Y). , M, C, K) developing device 14 (Y, M, C, K) that is developed with the toner of the developer 4 and primary transfer means for transferring each toner image to the intermediate transfer device 20. As an example, a primary transfer device 15 (Y, M, C, K) and a drum cleaning device that removes and cleans adhering substances such as toner remaining on the image holding surface of the photosensitive drum 11 after the primary transfer. 16 (Y, M, C, K) and the like.

The photoconductor drum 11 is formed by forming an image holding surface having a photoconductive layer (photosensitive layer) made of a photosensitive material on a peripheral surface of a cylindrical or cylindrical base material which is grounded. The photoconductor drum 11 is supported so as to rotate in a direction indicated by an arrow A when power is transmitted from a rotation driving device (not shown).

The charging device 12 is composed of a contact type charging roll which is arranged in contact with the photosensitive drum 11. A charging voltage is supplied to the charging device 12. As the charging voltage, when the developing device 14 performs reversal development, a voltage or current having the same polarity as the charging polarity of the toner supplied from the developing device 14 is supplied. As the charging device 12, a non-contact type charging device such as a scorotron arranged in a non-contact state on the surface of the photosensitive drum 11 may be used.

The exposure device 13 irradiates the peripheral surface of the charged photosensitive drum 11 with light configured according to image information input to the image forming apparatus 1 to form an electrostatic latent image. It is a thing. Image information (signal) input to the image forming apparatus 1 by an arbitrary means is transmitted to the exposure device 13 when a latent image is formed.

The exposure device 13 irradiates the photoconductor drum 11 with light according to image information by using LEDs (Light Emitting Diodes) as a plurality of light emitting elements arranged along the axial direction of the photoconductor drum 11 to form an electrostatic latent image. And an LED print head for forming the. As the exposure device 13, a device that deflects and scans laser light configured according to image information along the axial direction of the photoconductor drum 11 may be used.

As shown in FIG. 17, each of the developing devices 14 (Y, M, C, K) has an inside of a device housing 140 as an example of a developer accommodating container in which an opening and a container for accommodating the developer 4 are formed. A developing roll 141 that holds the developer 4 and conveys the developer 4 to a developing area facing the photoconductor drum 11, and a stirring and conveying member such as two screw augers that conveys the developer 4 while passing the developing roll 141 while stirring. 142 and 143, and a layer thickness regulating member 144 that regulates the amount (layer thickness) of the developer held on the developing roll 141 are arranged. A developing voltage is supplied to the developing device 14 between the developing roll 141 and the photoconductor drum 11 from a power supply device (not shown). Further, the developing roll 141 and the agitating/conveying members 142, 143 are rotated in a desired direction by the transmission of power from a rotation driving device (not shown). Further, as the four-color developer 4 (Y, M, C, K), a two-component developer containing a non-magnetic toner and a magnetic carrier is used.

The primary transfer device 15 (Y, M, C, K) is a contact type equipped with a primary transfer roll that is in contact with the periphery of the photosensitive drum 11 via the intermediate transfer belt 21 and rotates and is supplied with a primary transfer voltage. Transfer device. As the primary transfer voltage, a DC voltage having a polarity opposite to the charging polarity of the toner is supplied from a power supply device (not shown).

As shown in FIG. 17, the drum cleaning device 16 is arranged so as to contact with the container-shaped main body 160, which is partially open, and the peripheral surface of the photosensitive drum 11 after the primary transfer with a required pressure, and remains. The cleaning plate 161 removes and cleans the adhered substances such as toner, and the delivery member 162 such as a screw auger that collects and removes the adhered substances such as the toner removed by the cleaning plate 161 and conveys them to a recovery system (not shown). ing. As the cleaning plate 161, a plate-shaped member (for example, a blade) made of a material such as rubber is used.

As shown in FIG. 16, the intermediate transfer device 20 is arranged so as to be located above each image forming device 10 (Y, M, C, K). The intermediate transfer device 20 includes an intermediate transfer belt 21 that rotates in a direction indicated by an arrow B while passing a primary transfer position between the photosensitive drum 11 and a primary transfer device 15 (primary transfer roll), and an intermediate transfer belt 21. Are arranged on the outer peripheral surface (image holding surface) side of the intermediate transfer belt 21 supported by the belt support rolls 25 and a plurality of belt support rolls 22 to 26 that rotatably support the inner support surface in a desired state. A secondary transfer device 30 as an example of a secondary transfer member that secondarily transfers the toner image on the intermediate transfer belt 21 to the recording sheet 5, and an outer peripheral surface of the intermediate transfer belt 21 after passing through the secondary transfer device 30. The belt cleaning device 27 mainly removes adhered substances such as toner and paper powder remaining and adhered to the belt cleaning device 27.

As the intermediate transfer belt 21, for example, an endless belt made of a material in which a resistance adjusting agent such as carbon black is dispersed in a synthetic resin such as polyimide resin or polyamide resin is used. Further, the belt support roll 22 is configured as a drive roll that is rotationally driven by a drive device (not shown), the belt support roll 23 is configured as a face-up roll that holds the running position of the intermediate transfer belt 21, and the belt support roll 24 is The intermediate transfer belt 21 is configured as a tensioning roll that applies a tension, the belt support roll 25 is configured as a secondary transfer backup roll, and the belt support roll 26 is a back side of the intermediate transfer belt 21 with which the belt cleaning device 27 contacts. It is configured as a support roll that supports from.

As shown in FIG. 16, the secondary transfer device 30 moves the intermediate transfer belt 21 at the secondary transfer position, which is the outer peripheral surface portion of the intermediate transfer belt 21 supported by the belt support roll 25 of the intermediate transfer device 20. The contact-type transfer device includes a secondary transfer roll 31 that rotates while contacting the peripheral surface and is supplied with a secondary transfer voltage. The secondary transfer roll 31 or the belt support roll 25 of the intermediate transfer device 20 is supplied with a DC voltage having a polarity opposite to or the same as the charging polarity of the toner as a secondary transfer voltage.

The belt cleaning device 27 is arranged so as to contact with a container-shaped main body 270 having an opening at a part thereof and a peripheral surface of the intermediate transfer belt 21 after the secondary transfer with a required pressure to remove an adhered matter such as residual toner. The cleaning plate 271 is configured to be cleaned by a cleaning plate 271, and a delivery member 272 such as a screw auger that collects and removes adhered substances such as toner removed by the cleaning plate 271 and sends the collected product to a recovery system (not shown). As the cleaning plate 271, a plate-shaped member (for example, a blade) made of a material such as rubber is used.

The fixing device 40 includes a belt-shaped heating rotator 41 that is heated by a heating source so that the surface temperature is maintained at a required temperature, and a predetermined pressure in a state substantially along the axial direction of the heating rotator 41. It is configured by arranging a pressing rotary body 42 in the form of a belt or a drum that rotates in contact with each other. In the fixing device 40, a contact portion where the heating rotator 41 and the pressure rotator 42 contact each other serves as a fixing processing unit (nip portion) that performs a required fixing process (heating and pressing).

The paper feeding device 50 is arranged so as to be located below the image forming devices 10 (Y, M, C, K) for yellow (Y), magenta (M), cyan (C), and black (K). To be done. This paper feeding device 50 sends a single (or a plurality of) paper accommodating body 51 for accommodating the recording paper 5 of a desired size, type, etc. in a stacked state, and sends out the recording paper 5 one by one from the paper accommodating body 51. It is mainly composed of the devices 52 and 53. The sheet container 51 is attached so that it can be pulled out, for example, to the front side (side surface facing the user during operation) of the main body 1a, that is, the left side surface side in the illustrated example.

Examples of the recording paper 5 include plain paper, thin paper, OHP sheet, and the like used in electrophotographic copying machines, printers, and the like. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper 5 is also as smooth as possible. For example, coated paper obtained by coating the surface of plain paper with resin or the like, art paper for printing, etc. So-called thick paper or the like having a relatively large basis weight can also be used.

Between the sheet feeding device 50 and the secondary transfer device 30, a single (or a plurality of) sheet transport roll pair 54 or a transport guide 55 that transports the recording sheet 5 delivered from the sheet feeder 50 to the secondary transfer position. A sheet feeding/transporting path 56 is provided. The paper transport roll pair 54 is configured as a roll (registration roll) for adjusting the transport timing of the recording paper 5, for example. Further, between the secondary transfer device 30 and the fixing device 40, a conveyance guide for conveying the recording sheet 5 after the secondary transfer sent from the secondary transfer roll 31 of the secondary transfer device 30 to the fixing device 40. 57, 58, etc. are provided. Further, at a portion near the sheet discharge port formed on the main body 1a, the recording sheet 5 after fixing sent out from the fixing device 40 is transferred to a sheet discharge section 60 provided on an upper part of the main body 1a via a conveyance guide 59. A paper discharge roll pair 61 for discharging is arranged.

A switching gate 62 for switching the paper transport path is provided between the fixing device 40 and the paper discharge roll pair 61. The rotation direction of the paper discharge roll pair 61 can be switched between the normal rotation direction (discharge direction) and the reverse rotation direction. When images are formed on both sides of the recording paper 5, after the trailing edge of the recording paper 5 having an image formed on one side passes through the switching gate 62, the rotation direction of the paper discharge roll pair 61 is changed to the forward rotation direction (discharge). Direction) to the reverse direction. The recording sheet 5 conveyed in the reverse direction by the pair of sheet discharge rolls 61 has its conveying path switched by the switching gate 62 and is conveyed to the double-sided conveying path 63 formed along the substantially vertical direction. The double-sided conveyance path 63 includes a paper conveyance roll pair 64 that conveys the recording paper 5 to the paper conveyance roll pair 54 with the front and back reversed, and conveyance guides 65 to 68.

In FIG. 16, reference numeral 70 denotes a manual feed tray provided on the front surface (left side in the drawing) of the main body 1a of the image forming apparatus 1 so as to be openable and closable, and between the manual feed tray 70 and the paper transport roll pair 54. Is provided with a feeding device 71 for feeding the recording papers 5 stored in the manual feed tray 70 one by one, and a manual paper feed conveyance path 76 composed of a plurality of paper conveyance roll pairs 72 to 74, a conveyance guide 75, and the like. There is.

In addition, reference numeral 145 (Y, M, C, K) in FIG. 16 indicates a plurality of toners which are arranged in a direction perpendicular to the paper surface and are supplied to the corresponding developing device 14 (Y, M, C, K). 3A and 3B respectively show a toner cartridge containing a developer containing the toner.

Further, reference numeral 200 in FIG. 16 indicates a control circuit that controls the overall operation of the image forming apparatus 1. The control circuit 200 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory) (not shown), a bus connecting these CPU and ROM, a communication interface, and the like.

<Operation of image forming apparatus>
The basic image forming operation of the image forming apparatus 1 will be described below.

Here, an operation of forming a full-color image configured by combining toner images of four colors (Y, M, C, K) using the four image forming devices 10 (Y, M, C, K) Will be described.

When the image forming apparatus 1 receives the command information of the image forming operation (print) request, the four image forming apparatuses 10 (Y, M, C, K), the intermediate transfer device 20, the secondary transfer device 30, and the fixing device. 40 etc. starts.

Then, in each of the image forming devices 10 (Y, M, C, K), each photoconductor drum 11 first rotates in the direction indicated by the arrow A, and each charging device 12 causes the surface of each photoconductor drum 11 to move to a desired position. The polarity (negative polarity in the second embodiment) and the electric potential are charged respectively. An image obtained by the exposure device 13 converting the information of the image input to the image forming device 1 into each color component (Y, M, C, K) on the surface of the photosensitive drum 11 after charging. The light emitted based on the signal is emitted to form an electrostatic latent image of each color component having a required potential difference on the surface thereof.

Subsequently, each developing device 14 (Y, M, C, K) has a corresponding color charged to a required polarity (minus polarity) with respect to the electrostatic latent image of each color component formed on the photosensitive drum 11. (Y, M, C, K) toners are respectively supplied from the developing roll 141 to be electrostatically adhered to develop. By this development, the electrostatic latent image of each color component formed on each photoconductor drum 11 is visualized as a four-color (Y, M, C, K) toner image developed with the toner of the corresponding color. Be converted.

At this time, in the developing device 14 (Y, M, C, K), the developer 4 contained in the device housing 140 is conveyed while being agitated by the two agitating and conveying members 142 and 143, and is developed on the developing roll 141. Agent 4 is supplied. The layer thickness of the developer 4 supplied to the developing roll 141 is regulated by the layer thickness regulating member 144, and an electrostatic latent image formed on the surface of the photoconductor drum 11 is formed.

Subsequently, when the toner images of the respective colors formed on the photoconductor drums 11 of the respective image forming devices 10 (Y, M, C, K) are conveyed to the primary transfer position, the primary transfer devices 15 (Y, M, C, K) primary transfer the toner images of the respective colors in such a state that they are sequentially superposed on the intermediate transfer belt 21 rotating in the direction indicated by the arrow B of the intermediate transfer device 20.

In each of the image forming devices 10 that have completed the primary transfer, the drum cleaning device 16 cleans the surface of the photoconductor drum 11 by scraping off the adhering substances. As a result, each image forming device 10 is brought into a state in which the next image forming operation is possible.

Then, in the intermediate transfer device 20, the toner image primarily transferred by the rotation of the intermediate transfer belt 21 is held and conveyed to the secondary transfer position. On the other hand, in the paper feeding device 50, the required recording paper 5 is sent to the paper feeding and conveying path 56 in accordance with the image forming operation. In the paper feeding/transporting path 56, a pair of paper transporting rolls 54 serving as registration rolls feed the recording paper 5 to a secondary transfer position at a transfer timing and supply it.

At the secondary transfer position, the secondary transfer roll 31 of the secondary transfer device 30 secondarily transfers the toner images on the intermediate transfer belt 21 onto the recording paper 5 collectively. Further, in the intermediate transfer device 20 that has completed the secondary transfer, the belt cleaning device 27 removes and cleans the adhering substances such as toner remaining on the surface of the intermediate transfer belt 21 after the secondary transfer.

Subsequently, the recording sheet 5 to which the toner image has been secondarily transferred is separated from the intermediate transfer belt 21 and the secondary transfer roll 31 and then conveyed to the fixing device 40 via the conveyance guides 57 and 58. In the fixing device 40, the recording paper 5 after the secondary transfer is introduced into and passed through the contact portion between the rotating heating rotator 41 and the pressing rotator 42, so that a necessary fixing process (heating and heating) is performed. Pressure) to fix the unfixed toner image on the recording paper 5. Finally, when the recording paper 5 after the fixing is completed is an image forming operation for forming an image on one side thereof, the paper discharge roll pair 61 is used to, for example, install the paper on the upper portion of the main body 1a. It is discharged to the discharge unit 60.

When images are formed on both sides of the recording paper 5, the recording paper 5 with the image formed on one side is not discharged to the paper discharge section 60 by the paper discharge roll pair 61, and the paper discharge roll pair 61 is used. While holding the trailing edge of the recording paper 5, the rotation direction of the paper discharge roll pair 61 is switched to the reverse direction. The recording paper 5 conveyed in the opposite direction by the paper discharge roll pair 61 passes through the upper part of the switching gate 62, and then passes through the double-sided conveyance path 63 including the paper conveyance roll pair 64 and the conveyance guides 65 to 68. The sheet is conveyed to the sheet conveyance roll pair 54 with the front and back reversed. The paper transport roll pair 54 sends the recording paper 5 to the secondary transfer position in synchronization with the transfer timing to supply the secondary transfer position, forms an image on the back surface of the recording paper 5, and is installed on the main body 1a by the paper discharge roll pair 61. The sheet is discharged to the sheet discharge unit 60.

By the above operation, the recording paper 5 on which a full-color image formed by combining toner images of four colors is formed is output.

By the way, in the developing device 14 (Y, M, C, K), when the developer 4 is left in a high temperature and high humidity environment for a long time, the developer 4 contained in the device housing 140 is agglomerated, which is called blocking. May occur. In the developing device 14 (Y, M, C, K), when the developer 4 contained in the device housing 140 is blocked, the loads of the agitating and conveying members 142, 143 and the like that convey the developer 4 while stirring it. May become excessive, and the drive motor for driving the developing device 14 (Y, M, C, K) may be out of synchronization or the drive gear may be damaged.

Therefore, in the present second reference embodiment, as described later, the developing device 14 (Y, M, C, K) driving force transmission system for transmitting a driving force to is provided with a torque detector 100.

<Structure of driving force transmission device>
Figure 18 shows a driving force transmission apparatus according to the torque detecting device according to a second reference embodiment.

As shown in FIG. 18, the driving force transmission device 300 includes a driving motor 301 as a driving source. A drive gear 302 is attached to the rotation shaft of the drive motor 301. The drive gear 302 of the drive motor 301 is meshed with the first driven gear 303 for transmitting the driving force, and the diameter of the second driven gear 304 provided coaxially with the first driven gear 303 is set large. It is meshed with the third driven gear 306 that transmits the rotational driving force to the developing device 14 via the reduced gear 305. A fourth driven gear 307, which has the same structure as the third driven gear 306 and transmits the rotational driving force to the developing device 14, is coaxially arranged on the third driven gear 306. There is.

Meanwhile, the third driven gear 306 is provided between the fourth driven gear 307, as shown in FIG. 19, a torque detecting apparatus 100 according to the second reference embodiment is provided so as to intervene.

In the torque detection device 100, a rotational driving force is input by engaging a third driven gear 306 with a shaft support portion 112 configured as a gear of the first rotating body 101. Further, a fourth driven gear 307 is meshed with the shaft support portion 112 configured as a gear of the second rotating body 102, and from the fourth driven gear 307, a drive motor is provided via a coupling member 308. The rotational driving force is output to a developing device (not shown) as a load rotationally driven by 301.

<Operation of driving force transmission device>
As shown in FIG. 18, in the driving force transmission device 300, the rotational driving force of the driving motor 301 is changed from the driving gear 302 to the first driven gear 303, the second driven gear 304, the reduction gear 305, and the third driven gear. It is transmitted to the developing device 14 via 306 and the fourth driven gear 307. At that time, the torque detection device 100 is arranged between the third driven gear 306 and the fourth driven gear 307.

The control circuit 200 calculates the load torque T of the developing device 14 based on the signal output from the optical sensor 104 of the torque detection device 100, and monitors the load torque T constantly or at regular intervals. When the control circuit 200 determines that the load torque T of the developing device 14 detected by the torque detection device 100 exceeds the required upper limit value, the control circuit 200 stops the drive motor 301 and issues a message notifying the user of a warning to the operation panel or the like. To display.

As described above, the control circuit 200 stops the drive motor 301 when the load torque T of the developing device 14 detected by the torque detecting device 100 exceeds the required upper limit value, and thereby the developing device 14 (Y, M). , C, K), the occurrence of step-out of the drive motor 301 and the damage of the drive gear are avoided or suppressed.

[ Reference Embodiment 3]
20 and 21 shows a driving device of an image forming apparatus including a torque detection device according to a third reference embodiment.

As shown in FIGS. 20 and 21, the torque detection device 100 according to the third embodiment is configured such that the first and second rotating bodies also serve as driven gears for driving force transmission and coupling members. ing. In the torque detection device 100, the driven gear 306 (see FIG. 18) itself for transmitting the driving force, in which the shaft support portion 112 of the first rotating body 101 has teeth such as spur teeth formed on the outer periphery thereof. Further, the second rotating body 102 is provided with driving claws 127 and 128 for transmitting the driving force to a developing device (not shown) on the tip end surface of the shaft support portion 122, and transmits the rotational driving force to the developing device. It constitutes a coupling member. The driving claws 127, 128 are fitted to the driving force transmitting portion formed of a recess or the like, the driving claws 127, 128 provided on the developing device 14 side. The driving claw may be provided not on the second rotating body 102 but on the first rotating body 101, or may be provided on both the first and second rotating bodies 101, 102.

In this reference embodiment 3, as shown in FIGS. 20 and 21, the third driven gear 306, the fourth driven gear 307, and the coupling member 308 are unnecessary, reducing the number of parts and reducing the size of the apparatus. Can be realized.

[ Embodiment 1 ]
22 to 24 show a driving device of an image forming apparatus to which the torque detecting device according to the first embodiment is applied.

As shown in FIGS. 22 to 24, the torque detection device 100 according to the first embodiment does not use a torsion spring as an elastic member but is integrally formed with the first rotating body 101. The elastically deformable portion 118 is configured to be used.

The elastically deformable portion 118 is formed integrally with the flange portion 114 of the first rotating body 101. The elastically deformable portion 118 is formed at the end portion of the flange portion 114 along the circumferential direction so that the front surface shape is substantially V-shaped along the inner circumferential direction. As shown in FIG. 23, the tip portion 118 a of the elastically deformable portion 118 is locked to the pair of locking projections 124 and 125 of the second rotating body 102.

In the first embodiment , it is not necessary to separately provide an elastic member, the number of parts constituting the torque detection device 100 can be reduced, and the torque detection device 100 can be provided at low cost.

[ Reference Embodiment 4 ]
FIG. 25 shows a driving device of an image forming apparatus to which the torque detection device according to the fourth embodiment is applied.

As shown in FIG. 25, the torque detection device 100 according to the reference embodiment 4 is configured to use a coil spring 103' instead of using a torsion spring as an elastic member.

The coil spring 103 is provided between the support plate portion 119 provided on the rotation angle detection unit 115 of the first rotary body 101 and the support plate portion 128 provided on the rotation angle detection unit 123 of the second rotary body 102. It has been passed over.

In the reference fourth embodiment , the elastic force acting by the coil spring 103 can be set to be relatively small, which is effective when the detected torque is relatively small.

In the reference embodiments and the embodiments, the case where the transmissive optical sensor is used as the detecting means has been described, but the present invention is not limited to this, and the reflective optical sensor may be used. Of course.

Further, in the above-described reference embodiments and embodiments, the image forming apparatus is a full-color image forming apparatus that forms toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K). Although described, it is needless to say that the invention can be similarly applied to a monochrome image forming apparatus.

DESCRIPTION OF SYMBOLS 1... Image forming apparatus 1a... Image forming apparatus main body 11... Photosensitive drum 14... Developing device 100... Torque detecting device 101... First rotating body 102... Second rotating body 103... Torsion spring 104... Optical sensor

Claims (4)

A first rotating body arranged on the input side of the rotational driving force;
A second rotating body which is provided coaxially and rotatably with respect to the first rotating body and is arranged on the output side of the rotational driving force;
An elastic member that is integrally formed with the first rotating body and that applies an elastic force along the rotation direction between the first rotating body and the second rotating body,
Detection means for detecting a phase difference in rotation angle between the first rotating body and the second rotating body;
Equipped with
A torque detection device for detecting torque based on a phase difference in rotation angle between the first rotating body and the second rotating body detected by the detecting means. The detection means optically detects the first and second rotation angle detection units provided in a fan shape on the first rotating body and the second rotating body, respectively, to thereby detect the first rotation. The torque detection device according to claim 1, wherein a phase difference in rotation angle between a body and the second rotating body is detected. The elastic member is arranged on a rotation shaft of the first rotating body or the second rotating body, and one end of the elastic member is locked to the first rotating body and the other end is locked to the second rotating body. The torque detection device according to claim 1 or 2, which comprises a twisted spring. An image forming unit that is rotationally driven by a drive source
A torque detecting unit arranged between the drive source and the image forming unit, for detecting a load torque acting on the image forming unit;
Equipped with
An image forming apparatus using the torque detection device according to claim 1 as the torque detection means.

Images