JP2018031691A - Torque detection device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the degree of freedom of a torque detection position compared with a case where torque is detected by detecting a current flowing in a driving source.SOLUTION: A torque detection device comprises: a first rotating body 101 that is arranged on a side to which a rotational driving force is input; a second rotating body 102 that is provided coaxially and rotatably with respect to the first rotating body 101 and arranged on a side from which the rotational driving force is output; an elastic member 103 that causes an elastic force along a rotation direction to act between the first rotating body 101 and the second rotating body 102; and detection means 104 that detects a phase difference in rotation angle between the first rotating body 101 and the second rotating body 102. The torque detection device detects torque on the basis of the phase difference in rotation angle between the first rotating body 101 and the second rotating body 102 detected by the detection means 104.SELECTED DRAWING: Figure 1

Description

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

  2. Description of the Related Art Conventionally, some torque detection devices are configured to use a drive motor as a drive source for rotationally driving a drive target and detect 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 already been proposed.

  Patent Document 1 discloses a developing device that develops a toner image by attaching 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 the toner image is transferred. In an image forming apparatus including a cleaning device that removes and collects, a recycling unit that transports the collected toner collected by the cleaning device to the developing device side, and a transport load of the recycling unit increases beyond a predetermined load And an overload detecting means for detecting the overload state.

  Patent Document 2 discloses a developer container that stores a developer, a developing unit that visualizes a latent image formed on an image carrier using the developer, and a developer that is stored in the developer container. In the image forming apparatus having a developer conveying member for conveying or stirring the toner, a driving force transmitting means for transmitting a driving force for rotating the developer conveying member, and a rotation speed of the developer conveying member The developer conveying member swings in response to a change in load resistance caused by the developer when entering the developer and retracting from the stored developer, and the swing The amount of developer in the developer container is sequentially detected by detecting the change in the rotation speed caused by the above-described detection means.

  Patent Document 3 discloses a collection container that receives and accommodates a developer collected from an image carrier, a stirring member that stirs the developer in the collection container, and two shafts that transmit rotational force to the stirring member. A torque limiter that couples and shuts off the shafts, and a fullness determination unit that detects a shutoff state between the shafts and determines that the recovery container is full of developer based on the detected shutoff state Each of the cams provided on the shafts to be engaged with each other, and one of the cams is urged and moved to move each of the cams. Are connected to each other and the shafts are coupled to each other. The spring is provided on the one cam, and the first rotating member that rotates together with the one cam and the one cam. Positioned along a provided axis, In which it is provided between the second rotary member which rotates together with the square of the cam.

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

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

  Another object of the present invention is to improve torque detection accuracy as compared with the case of detecting torque by detecting a current flowing through a drive source.

The invention described in claim 1 includes a first rotating body arranged on the input side of the rotational driving force;
A second rotating body provided coaxially and rotatably with respect to the first rotating body and disposed on the output side of the rotational driving force;
An elastic member for applying an elastic force along a rotation direction between the first rotating body and the second rotating body;
Detecting means for detecting a phase difference in rotation angle between the first rotating body and the second rotating body;
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 detectors provided in a fan shape on the first rotating body and the second rotating body, respectively. The torque detection device according to claim 1, wherein a phase difference between rotation angles of 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 disposed on a rotation shaft of the first rotating body or the second rotating body, one end is on the first rotating body, and the other end is on the other end. The torque detection device according to claim 1, wherein the torque detection device includes a torsion spring locked to each of the second rotating bodies.

According to a fourth aspect of the present invention, there is provided image forming means that is rotationally driven by a drive source;
A torque detecting means that is disposed between the drive source and the image forming means and detects a load torque acting on the image forming means;
With
An image forming apparatus using the torque detection device according to claim 1 as the torque detection means.

  According to the first aspect of the present invention, 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 first aspect of the present invention, the torque detection accuracy can be improved as compared with the case where the torque flowing is detected by detecting the current flowing through the drive source.

  According to the 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 rotating body and the second rotating body, respectively. Compared to the case where the phase difference of the rotation angle between the first rotating body and the second rotating body is not detected, the first rotating body and the second rotating body can be detected with a simple configuration. The phase difference of the rotation angle with the rotating body can be detected.

  According to the invention described in claim 3, the elastic member is not composed of a torsion spring in which one end is locked to the first rotating body and the other end is locked to the second rotating body. Compared to the case, the elastic member can be downsized.

  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. And can easily cope with torque fluctuations of the image forming means.

It is a perspective view which shows the torque detection apparatus which concerns on Embodiment 1 of this invention. 1 is an exploded perspective view showing a torque detector according to Embodiment 1 of the present invention. FIG. 4A is a perspective view showing the surface of the first rotating body, and FIG. 4B is a perspective view showing the back surface of the first rotating body. FIG. 4A is a perspective view showing the surface of the second rotating body, and FIG. 4B is a perspective view showing the back surface of the second rotating body. It is a top view which shows the torque detection apparatus which concerns on Embodiment 1 of this invention. It is the EE arrow line figure 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 views showing the operation of the torque detection device according to Embodiment 1 of the present invention. It is a schematic diagram which shows the principle of the torque detection apparatus which concerns on Embodiment 1 of this invention. (A), (b), and (c) are schematic diagrams respectively showing the principle of the torque detection device according to Embodiment 1 of the present invention. It is a schematic diagram which shows the principle of the torque detection apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the principle of the torque detection apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the exposure time of an optical sensor, and the load torque T. It is a graph which shows the relationship between angle (theta) of the 1st and 2nd rotation angle detection part, and the load torque. It is a block diagram which shows the image forming apparatus to which the torque detection apparatus which concerns on Embodiment 2 of this invention is applied. It is a block diagram which shows the image formation part of the image forming apparatus to which the torque detection apparatus which concerns on Embodiment 2 of this invention is applied. It is a block diagram which shows a driving force transmission apparatus. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the driving force transmission device to which the torque detection apparatus which concerns on Embodiment 3 of this invention is applied. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 3 of this invention. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 4 of this invention. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 4 of this invention. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 4 of this invention. It is a perspective block diagram which shows the torque detection apparatus which concerns on Embodiment 5 of this invention.

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

[Embodiment 1]
1 and 2 show a torque detection apparatus according to the first embodiment. FIG. 1 shows the entirety of the torque detection device, and FIG. 2 shows a state where components of the torque detection device are disassembled.

  As shown in FIG. 1 and FIG. 2, the torque detection device 100 is roughly divided into a first rotating body 101 disposed on the input side of the rotational driving force and a coaxial shape with respect to the first rotating body 101. An elastic force is applied along the rotational direction between the second rotating body 102 provided rotatably and arranged on the output side of the rotational driving force, and the first rotating body 101 and the second rotating body 102. A torsion spring 103 (see FIG. 2) as an example of the elastic member to be moved, and a transmission type as an example of detection means for detecting the phase difference of the rotation angle between the first rotating body 101 and the second rotating body 102 The optical sensor 104 is provided. The first rotating body 101 and the second rotating body 102 are supported so as to be rotatable with respect to the rotating shaft 105.

  As shown in FIG. 3, the first rotating body 101 includes a shaft support portion 112 formed in a columnar shape having an insertion hole 111 into which the rotation shaft 105 is inserted at the center, and the shaft support portion 112 on one side surface of the shaft support portion 112. A disk part 113 formed in a disk shape having an outer diameter (diameter) larger than the support part 112, and formed so as to form a part of a cylindrical shape in a state of standing along the axial direction at the outer peripheral end of the disk part 113 The flange portion 114 is formed in a fan shape so as to form a required center angle β smaller than the center angle α of the flange portion 114 outward in the radial direction on the outer peripheral surface of the front end along the axial direction of the flange portion 114. The rotation angle detection unit 115 is integrally formed. In addition, an insertion hole 111 of the shaft support portion 112 is provided in the center of the disc portion 113, and a cylindrical mounting portion 116 for mounting the torsion spring 103 is flanged along the axial direction. It is provided to have the same height (length) as the portion 114. Further, the flange 114 has a locking groove 117 for locking the linearly formed one end 131 a of the torsion spring 103 at a position corresponding to the one end 115 b of the rotation angle detecting unit 115. It is formed to a depth that reaches the surface of the portion 113. The first rotating body 101 is rotatably mounted on the rotating shaft 105. The first rotator 101 may be configured as a mere rotator, or may be configured as a gear for transmitting a rotational driving force by forming teeth such as spur teeth on the outer periphery of the shaft support portion 112. The first rotating body 101 is integrally formed by synthetic resin injection molding or the like. Further, when a large torque acts on the first rotating body 101, it may be formed integrally with 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 shielding 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 with 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. Normally, one end edge 115 a along the rotation direction (circumferential direction) of the rotation angle detection unit 115 formed in the fan shape of the first rotating body 101 is detected by the optical sensor 104. In the first rotating body 101, one end 131a of the torsion spring 103 is locked to the other end edge 115b of the rotation angle detecting unit 115, and the other end edge 115b of the rotation angle detecting unit 115 is engaged. Is the point of action where the rotational force acts.

  On the other hand, as shown in FIG. 4, the second rotating body 102 includes a cylindrical support 122 having a cylindrical shape having an insertion hole 121 into which the rotary shaft 105 is inserted at the center, and one side of the support 122. The second rotation angle detector 123 formed in a fan shape so as to form a required central angle γ outward in the radial direction, and opposed to the outer surface of the second rotation angle detector 123 via a required gap A pair of locking protrusions 124 and 125 are formed to lock the other end 131b of the torsion spring 103 formed in a straight line. In addition, the arc portion 126 having a small outer diameter formed in the opening of the second rotation angle detection unit 123 is configured to have the same outer diameter as the disk portion 113 of the first rotating body 101, for example. The As shown in FIGS. 5 and 6, the pair of locking protrusions 124 and 125 are arranged so 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 mounted on the rotating shaft 105. The second rotating body 102 may be configured as a mere rotating body, but the shaft support portion 122 may be configured as a gear having teeth such as spur teeth formed on the outer periphery and transmitting a rotational driving force. The second rotating body 102 is also integrally formed by synthetic resin injection molding or the like. Further, as in the case of the first rotating body 101, the second rotating body 102 may of course be integrally formed with metal or the like instead of synthetic resin when a large torque acts.

  Similar to the rotation angle detection unit 115 of the first rotator 101, the rotation angle detection unit 123 of the second rotator 102 blocks the light from the optical sensor 104, thereby preventing the second rotator 102 from rotating. 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 with the first rotating body 101, that is, the second rotating body 102. And the phase difference between the rotation angles of the first rotator 101 are detected. Normally, one end edge 123a along the rotation direction (circumferential direction) of the rotation angle detection unit 123 formed in the fan shape of the second rotating body 102 is detected by the optical sensor 104. The rotation angle detection unit 123 of the second rotating 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 rotating body 101. ing. In the second rotating body 102, the other end 131 b of the torsion spring 103 is locked in the vicinity of the other end 123 a of the rotation angle detection unit 123, and the other end edge of the rotation angle detection unit 123. 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 where the first rotation angle detection unit 115 and the second rotation angle detection unit 123 overlap each other. Initially, the first rotating body 101 and the second rotating body 102 are in a state in which no torque acts between them, and the edge 115a and the edge 123a of the second rotation angle detector 123 are They are combined so that a gap with a predetermined angle θ ₀ is formed therebetween. That is, the torsion spring 103 is configured so that one end portion 131 a of the torsion spring 103 is locked to the groove portion 117 of the first rotating body 101 in a free state where no torque is applied. The end 131 b is locked between the pair of locking protrusions 124 and 125 of the second rotating body 102, so that the end edge 115 a of the first rotation angle detection unit 115 and the second rotation angle detection unit 123. A gap with a predetermined angle θ ₀ is formed between the edge 123a and the edge 123a.

  As shown in FIG. 7, the torsion spring 103 has an annular portion 131c in which a metal elastic wire 131 having a required rectangular or circular cross section is wound in an annular shape along the axial direction a required number of times. And both ends 131a and 131b of the elastic wire 131 are configured to extend in the tangential direction of the annular portion 131c. The torsion spring 103 is formed by appropriately adjusting the cross-sectional shape and thickness of the metal elastic wire 131, the diameter of the annular portion 131c, the number of windings, and the like. The elastic force (torsional rigidity) along the rotation direction is set to a predetermined value. In addition, the one end part 131b of the elastic wire 131 is formed longer than the other end part 131a.

  As shown in FIG. 1 and FIG. 2, the first and second rotating bodies 101 and 102 have the rotating shaft 105 inserted into the insertion hole 111 of the first rotating body 101 and the first rotating body 101 is attached. The annular portion 131 c of the torsion spring 103 is inserted into the portion 116, and one end portion 131 a 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 rotation angle detecting section 115 of the first rotating body 101 and the rotation angle detecting section 123 of the second rotating body 102 overlap each other. It is mounted via. The other end 131 b of the torsion spring 103 is locked to the pair of locking protrusions 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, as shown in FIG. 8, the optical sensor 104 includes a sensor main body 151 formed in an elongated rectangular parallelepiped shape. On one side surface of the sensor main body 151, a pair of facing portions 152 and 153 are provided so as to face each other with the rotation angle detecting portions 115 and 123 of the first and second rotating bodies 101 and 102 interposed therebetween. . One facing portion 152 incorporates a light emitting element such as an LED (not shown). The other facing portion 153 includes a light receiving element such as a photodiode (not shown). 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, whereby the first and second rotating bodies 101, Each rotation angle detection unit 115, 123 of 102 is 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 means including a CPU for calculating and detecting torque via a cable (not shown) connected to the socket portion 156. Sent to the circuit 200.

<Detection principle of torque detector>
As shown in FIG. 1, the torque detection apparatus 100 receives a rotational driving force of a driving motor (not shown) as a driving source that is input to the first rotating body 101 and is input to the first rotating body 101. Is transmitted to the second rotating body 102 via the torsion spring 103, and a 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 provided coaxially and rotatably with respect to the rotating shaft 105, and the first rotating body 101 and the second rotating body 102 are provided. An elastic force (torsional rigidity) along the rotational direction is applied to the rotating body 102 by the torsion spring 103.

  As shown in FIG. 9, when the torque detector 100 rotates the first rotating body 101, a rotational driving force is applied to the second rotating body 102 in a state where torsional rigidity is applied 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 has the load torque T applied 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 is configured so that the torque does not act between the first rotating body 101 and the second rotating body 102, and the first rotating body 101. Is set such that a required phase difference θ ₀ (= θ) initially exists between the rotation angle detection unit 115 of the second rotation body and the rotation angle detection unit 123 of the second rotating body 102.

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

  9A, 9B, 11B, and 11C show the rotation angle detector 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. FIG. This shows the state where the angle θ formed by the detection unit 123, that is, the phase difference is different. As load torque T (T2> T1) increases, rotation angle difference θ (phase difference) formed by rotation angle detector 115 of first rotating body 101 and rotation angle detecting section 123 of second rotating body 102 is increased. ) Increases (θ2> θ1).

Therefore, the gap (rotation angle difference 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 is 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 obtained by the arithmetic processing by the control circuit 200 based on the following expression which is the relational expression represented by [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 relational expression shown in Equation 1 based on the signal corresponding to the exposure time t output from the optical sensor 104. In the relational expression shown in Equation 1, the rotational speed ω is shown as a known value.

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

Further, as shown in FIG. 15, when the rotational speed ω is a known value, the control circuit 200 obtains the angle θ based on the signal corresponding to the exposure time t output from the photosensor 104,
You may comprise so that the load torque T may be calculated | required by calculation based on angle (theta).

  Thus, in the torque detection device 100 according to the above-described embodiment, it is not necessary to detect the current flowing through the drive source and the driving force is lower than when detecting the torque by detecting the current flowing through the drive source. Torque can be detected at an arbitrary position for transmission, 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 embodiment, it is not necessary to detect the current flowing through the drive source, as compared with the case where the current flowing through the drive source is detected and the torque is detected. The phase difference between the rotation angles of the rotating bodies 101 and 102 can be detected with high accuracy by the optical sensor 104, so that the torque detection accuracy can be improved. Can do.

[Embodiment 2]
16 and 17 illustrate an image forming apparatus to which the torque detection device according to the second embodiment is applied. FIG. 16 shows the entire image forming apparatus, and FIG. 17 shows an image forming unit 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 apparatuses 10 as an example of an image forming unit that forms a toner image developed with toner constituting the developer 4, and toner images formed by the image forming apparatuses 10. An intermediate transfer device 20 that respectively holds and finally transports it to a secondary transfer position for secondary transfer onto a recording sheet 5 as an example of a recording medium, and a required recording to be supplied to the secondary transfer position of the intermediate transfer device 20 A paper feeding device 50 that accommodates and conveys the paper 5 and a fixing device 40 that fixes the toner image on the recording paper 5 that is secondarily transferred by the intermediate transfer device 20 are provided. In the figure, reference numeral 1a denotes a main body of the image forming apparatus 1, and the main body 1a is formed of a support structure member, an exterior cover, and the like.

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

  The yellow (Y), magenta (M), cyan (C), and black (K) image forming devices 10 (Y, M, C, and K) each include an electrostatic latent image as shown in FIGS. A rotating photosensitive drum 11 is provided as an example of an image holding member for holding an image, and the following devices as examples of toner image forming means are mainly disposed around the photosensitive drum 11. ing. The main devices are a charging device 12 that charges a peripheral surface (image holding surface) on the photosensitive drum 11 on which an image can be formed to a required potential, and image information (on the charged peripheral surface of the photosensitive drum 11). The 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 (for each color) having a potential difference, and the corresponding color (Y , M, C, K) developing device 14 (Y, M, C, K) which develops with toner of developer 4 to form a toner image, and primary transfer means for transferring each toner image to intermediate transfer device 20 Primary transfer device 15 (Y, M, C, K) as an example, and drum cleaning device that removes adhering matter such as toner remaining on the image holding surface of the photosensitive drum 11 after the primary transfer and cleans it. 16 (Y, M, C, K).

  The photosensitive drum 11 is formed by forming an image holding surface having a photoconductive layer (photosensitive layer) made of a photosensitive material on the peripheral surface of a cylindrical or columnar base material to be grounded. The photosensitive 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 includes a contact-type charging roll that is disposed 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 disposed in a non-contact state on the surface of the photosensitive drum 11 may be used.

  The exposure device 13 forms an electrostatic latent image by irradiating the circumferential surface of the charged photosensitive drum 11 with light configured according to image information input to the image forming apparatus 1. Is. When the latent image is formed, image information (signal) input to the image forming apparatus 1 by any means is transmitted to the exposure apparatus 13.

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

  As shown in FIG. 17, each of the developing devices 14 (Y, M, C, K) has an interior of a device housing 140 as an example of a developer storage container in which an opening and a storage chamber for the developer 4 are formed. In addition, a developing roller 141 that holds the developer 4 and conveys it to the developing region facing the photosensitive drum 11, and a stirring and conveying member such as two screw augers that convey the developer 4 while passing the developing roller 141 while stirring the developer 4. 142, 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 from a power supply device (not shown) between the developing roll 141 and the photosensitive drum 11. Further, the developing roll 141 and the agitating / conveying members 142 and 143 are rotated in a required direction by receiving 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 nonmagnetic toner and a magnetic carrier is used.

  The primary transfer device 15 (Y, M, C, K) is in contact with the periphery of the photosensitive drum 11 via an intermediate transfer belt 21 and rotates, and a contact type provided with a primary transfer roll to which a primary transfer voltage is supplied. This is a 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 disposed so as to be in contact with the peripheral surface of the photosensitive drum 11 after the primary transfer with a container-shaped main body 160 that is partially opened at a required pressure. A cleaning plate 161 that removes and removes deposits such as toner, and a sending member 162 such as a screw auger that collects and removes deposits such as toner removed by the cleaning plate 161 and sends them to a collection system (not shown). ing. As the cleaning plate 161, a plate-like 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 disposed so as to exist at a position 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 the 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 hold the toner in a desired state from the inner surface thereof. The secondary transfer device 30 as an example of a secondary transfer member for secondary transfer of the toner image on the intermediate transfer belt 21 to the recording paper 5, and the outer peripheral surface of the intermediate transfer belt 21 after passing through the secondary transfer device 30 And a belt cleaning device 27 that removes and adheres toner, paper dust, and other adhering matter.

  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 driving device (not shown), the belt support roll 23 is configured as a surface roll that holds the traveling position of the intermediate transfer belt 21, and the belt support roll 24 is The intermediate transfer belt 21 is configured as a tension applying roll that applies tension. The belt support roll 25 is configured as a secondary transfer backup roll. It is comprised as a support roll which supports from.

  As shown in FIG. 16, the secondary transfer device 30 is configured such that the intermediate transfer belt 21 has a secondary transfer position at the secondary transfer position that is the outer peripheral surface portion of the intermediate transfer belt 21 supported by the belt support roll 25 in the intermediate transfer device 20. The contact type transfer device includes a secondary transfer roll 31 that rotates in contact with a 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 or the same as the charging polarity of the toner as a secondary transfer voltage.

  The belt cleaning device 27 is disposed so as to come into contact with the peripheral surface of the intermediate transfer belt 21 after the secondary transfer and the container-like main body 270 partially opened to remove adhered matters such as residual toner. The cleaning plate 271 is cleaned, and the adhering material such as toner removed by the cleaning plate 271 is collected and sent to a collecting system (not shown) and sent out such as a screw auger. As the cleaning plate 271, a plate-like 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. A belt-type or drum-type pressurizing rotator 42 rotating in contact with each other is arranged. In the fixing device 40, a contact portion where the heating rotator 41 and the pressing rotator 42 come into contact becomes a fixing processing portion (nip portion) that performs a required fixing process (heating and pressing).

  The sheet feeding device 50 is disposed so as to be present at a position below the yellow (Y), magenta (M), cyan (C), and black (K) image forming devices 10 (Y, M, C, K). Is done. The paper feeding device 50 is a single (or plural) paper container 51 that accommodates recording papers 5 of a desired size and type, and sends out the recording paper 5 from the paper container 51 one by one. It is mainly composed of devices 52 and 53. The paper container 51 is attached, for example, so that it can be pulled out to the front side (side surface on which the user faces during operation) of the main body 1a, that is, the left side surface in the illustrated example.

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

  Between the paper feeding device 50 and the secondary transfer device 30, a single (or plural) paper conveyance roll pair 54, a conveyance guide 55, and the like that convey the recording paper 5 delivered from the paper supply device 50 to the secondary transfer position. Is provided. The pair of paper transport rolls 54 is configured as, for example, a roll (registration roll) that adjusts the transport timing of the recording paper 5. Further, a conveyance guide for conveying the recording sheet 5 after the secondary transfer fed from the secondary transfer roll 31 of the secondary transfer device 30 to the fixing device 40 between the secondary transfer device 30 and the fixing device 40. 57, 58, etc. are provided. Further, in the portion near the paper discharge port formed in the main body 1 a, the recording paper 5 after fixing sent out from the fixing device 40 is fed to a paper discharge portion 60 provided on the upper portion of the main body 1 a via the conveyance guide 59. A paper discharge roll pair 61 for discharging is disposed.

  Between the fixing device 40 and the paper discharge roll pair 61, a switching gate 62 for switching the paper transport path is provided. The rotation direction of the paper discharge roll pair 61 can be switched between a normal rotation direction (discharge direction) and a reverse rotation direction. When images are formed on both sides of the recording paper 5, after the rear end 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 set to the normal rotation direction (discharge). Direction) to reverse direction. The recording paper 5 transported in the reverse direction by the paper discharge roll pair 61 is transported to the double-sided transport path 63 formed so as to be substantially along the vertical direction by switching the transport path by the switching gate 62. The duplex conveyance path 63 includes a sheet conveyance roll pair 64 that conveys the recording sheet 5 to the sheet conveyance roll pair 54 with the front and back sides reversed, and conveyance guides 65 to 68.

  In FIG. 16, reference numeral 70 denotes a manual feed tray that is openably and closably provided on the front surface (left side surface in the figure) of the main body 1 a of the image forming apparatus 1, and between the manual feed tray 70 and the pair of paper transporting rolls 54. Is provided with a feeding device 71 for feeding the recording sheets 5 stored in the manual feed tray 70 one by one, and a manual feed conveyance path 76 including a plurality of sheet conveyance roll pairs 72 to 74, a conveyance guide 75, and the like. Yes.

  Also, reference numeral 145 (Y, M, C, K) in FIG. 16 is arranged in a plurality along a direction perpendicular to the paper surface, and at least the toner supplied to the corresponding developing device 14 (Y, M, C, K). Each of the toner cartridges containing the developer is shown.

  Further, reference numeral 200 in FIG. 16 indicates a control circuit that comprehensively controls the 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), a bus connecting these CPUs and ROM, a communication interface, and the like (not shown).

<Operation of Image Forming Apparatus>
Hereinafter, a basic image forming operation by the image forming apparatus 1 will be described.

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

  When the image forming apparatus 1 receives command information for requesting an image forming operation (printing), the four image forming apparatuses 10 (Y, M, C, K), the intermediate transfer apparatus 20, the secondary transfer apparatus 30, and the fixing apparatus. 40 etc. starts.

  In each image forming device 10 (Y, M, C, K), each photoconductor drum 11 is first rotated in the direction indicated by an arrow A, and each charging device 12 makes a required surface of each photoconductor drum 11 on the surface. Each is charged to a polarity (negative polarity in Embodiment 2) and a potential. Subsequently, the exposure apparatus 13 converts the image information input to the image forming apparatus 1 into each color component (Y, M, C, K) with respect to the surface of the photosensitive drum 11 after charging. The light emitted on the basis of the signal is irradiated to form an electrostatic latent image of each color component composed of a required potential difference on the surface.

  Subsequently, each developing device 14 (Y, M, C, K) has a corresponding color charged with a required polarity (minus polarity) with respect to the electrostatic latent image of each color component formed on the photosensitive drum 11. Development is performed by supplying (Y, M, C, K) toner from the developing roll 141 and electrostatically adhering them. By this development, the electrostatic latent images of the respective color components formed on the respective photosensitive drums 11 are visualized as toner images of four colors (Y, M, C, K) respectively developed with the corresponding color toners. It becomes.

  At that time, in the developing device 14 (Y, M, C, K), the developer 4 accommodated in the device housing 140 is transported while being stirred by the two stirring transport members 142 and 143, and is developed on the developing roll 141. Agent 4 is supplied. Further, the developer 4 supplied to the developing roll 141 is regulated in layer thickness by the layer thickness regulating member 144, and an electrostatic latent image formed on the surface of the photosensitive drum 11 is formed.

  Subsequently, when each color toner image formed on the photosensitive drum 11 of each image forming device 10 (Y, M, C, K) is conveyed to the primary transfer position, the primary transfer device 15 (Y, M, C, K) are primarily transferred in such a manner that the toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 21 that rotates in the direction indicated by the arrow B of the intermediate transfer device 20.

  Further, in each image forming apparatus 10 for which the primary transfer has been completed, the drum cleaning device 16 cleans the surface of the photosensitive drum 11 by removing the adhered material so as to scrape off. Thereby, each image forming apparatus 10 is brought into a state in which the next image forming operation can be performed.

  Subsequently, 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, the paper feeding device 50 sends out the required recording paper 5 to the paper feeding conveyance path 56 in accordance with the image forming operation. In the paper feed transport path 56, a pair of paper transport rolls 54 as registration rolls feeds the recording paper 5 to the secondary transfer position in accordance with the transfer timing.

  At the secondary transfer position, the secondary transfer roll 31 of the secondary transfer device 30 collectively transfers the toner image on the intermediate transfer belt 21 onto the recording paper 5. Further, in the intermediate transfer device 20 after the secondary transfer is completed, the belt cleaning device 27 removes adhered matters such as toner remaining on the surface of the intermediate transfer belt 21 after the secondary transfer, and cleans it.

  Subsequently, the recording paper 5 on which the toner image has been secondarily transferred is peeled 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 necessary fixing process (heating and heating) is performed by introducing and passing the recording sheet 5 after the secondary transfer through the contact portion between the rotating rotating body 41 for heating and the rotating body 42 for pressing. Pressure) to fix the unfixed toner image on the recording paper 5. Finally, the recording paper 5 after the fixing is completed is, for example, a paper set on the upper portion of the main body 1a by the paper discharge roll pair 61 in the image forming operation only for forming an image on one side. It is discharged to the discharge unit 60.

  When forming images on both sides of the recording paper 5, the recording paper discharge roller pair 61 does not discharge all of the recording paper 5 having an image formed on one side to the paper discharge unit 60 by the paper discharge roll pair 61. While the trailing edge of the recording paper 5 is held, the rotation direction of the paper discharge roll pair 61 is switched to the reverse direction. The recording paper 5 conveyed in the reverse 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, the conveyance guides 65 to 68, and the like. The paper is transported to the pair of paper transport rollers 54 with the front and back sides reversed. The pair of paper transporting rolls 54 feeds the recording paper 5 to the secondary transfer position in accordance with the transfer timing, forms an image on the back surface of the recording paper 5, and is installed on the upper portion of the main body 1a by the paper discharge roll pair 61. The paper is discharged to the paper discharge unit 60.

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

  By the way, in the developing device 14 (Y, M, C, K), when it is left for a long time in a high-temperature and high-humidity environment, the developer 4 accommodated inside the device housing 140 is agglomerated called blocking. May occur. In the developing device 14 (Y, M, C, K), when blocking occurs in the developer 4 accommodated in the device housing 140, loads such as stirring and conveying members 142 and 143 that convey the developer 4 while stirring the developer 4 are loaded. May become excessive, and the drive motor that drives the developing device 14 (Y, M, C, K) may be stepped out or the drive gear may be damaged.

  Therefore, in the second embodiment, as described later, a driving force transmission system that transmits a driving force to the developing device 14 (Y, M, C, K) includes the torque detection device 100.

<Configuration of driving force transmission device>
FIG. 18 shows a driving force transmission device to which the torque detection device according to the second embodiment is applied.

  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 second driven gear 304 provided coaxially with the first driven gear 303 is set to have a large diameter. It is meshed with a third driven gear 306 that transmits a rotational driving force to the developing device 14 through the reduced gear 305. Further, the third driven gear 306 is configured in the same manner as the third driven gear 306, and a fourth driven gear 307 that transmits the rotational driving force to the developing device 14 is coaxially spaced apart. Yes.

  Incidentally, between the third driven gear 306 and the fourth driven gear 307, as shown in FIG. 19, the torque detection device 100 according to the second embodiment is interposed.

  In the torque detection device 100, the third driven gear 306 is engaged with the shaft support portion 112 configured as the gear of the first rotating body 101, and the rotational driving force is input. A fourth driven gear 307 is meshed with the shaft support portion 112 configured as a gear of the second rotating body 102, and the drive motor is connected to the fourth driven gear 307 via a coupling member 308. A rotational driving force is output to a developing device (not shown) as a load that is 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. 306 is transmitted to the developing device 14 via the fourth driven gear 307. At that time, the torque detection device 100 is disposed between the third driven gear 306 and the fourth driven gear 307.

  The control circuit 200 obtains the load torque T of the developing device 14 by calculation based on a 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 has exceeded the required upper limit, the control circuit 200 stops the drive motor 301 and displays a message notifying the user of a warning (not shown). To display.

  As described above, the control circuit 200 stops the driving 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, thereby developing the developing device 14 (Y, M , C, K), the occurrence of step-out of the drive motor 301 and damage to the drive gear are avoided or suppressed.

[Embodiment 3]
20 and 21 show a drive device for an image forming apparatus to which the torque detection device according to the third embodiment is applied.

  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 a driven gear and a coupling member for transmitting driving force. Yes. In the torque detection device 100, the shaft support 112 of the first rotating body 101 constitutes the driven gear 306 for driving force transmission (see FIG. 18) itself in which teeth such as spur teeth are formed on the outer periphery thereof. The second rotating body 102 includes driving claws 127 and 128 for transmitting a driving force to a developing device (not shown) on the distal end surface of the shaft support portion 122, and transmits the rotational driving force to the developing device. A coupling member is configured. The driving claws 127 and 128 are fitted into a driving force transmitting portion formed of a concave portion or the like, with the driving claws 127 and 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 on both the first and second rotating bodies 101 and 102.

  In the third embodiment, as shown in FIGS. 20 and 21, the third driven gear 306, the fourth driven gear 307, and the coupling member 308 are not necessary, and the number of parts is reduced and the apparatus is downsized. Is possible.

[Embodiment 4]
22 to 24 show a drive device of an image forming apparatus to which the torque detection device according to the fourth embodiment is applied.

  As shown in FIGS. 22 to 24, the torque detection device 100 according to the fourth embodiment is formed integrally with the first rotating body 101 instead of using a torsion spring as an elastic member. The elastic deformation portion 118 is used.

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

  In the fourth 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.

[Embodiment 5]
FIG. 25 shows a drive device of an image forming apparatus to which the torque detection device according to the fifth embodiment is applied.

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

  The coil spring 103 is interposed between the support plate portion 119 provided in the rotation angle detection unit 115 of the first rotary body 101 and the support plate portion 128 provided in the rotation angle detection unit 123 of the second rotary body 102. It is being handed over.

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

  In the above-described embodiment, the case where a transmission type photosensor is used as the detection unit has been described. However, the present invention is not limited to this, and it is needless to say that a reflection type photosensor may be used. .

  In the above embodiment, a full-color image forming apparatus that forms toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K) has been described as an image forming apparatus. Of course, the present invention can be similarly applied to the image forming apparatus.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 1a ... Image forming apparatus main body 11 ... Photosensitive drum 14 ... Developing apparatus 100 ... Torque detection apparatus 101 ... 1st rotary body 102 ... 2nd rotary body 103 ... Torsion spring 104 ... Optical sensor

Claims (4)

A first rotating body disposed on the input side of the rotational driving force;
A second rotating body provided coaxially and rotatably with respect to the first rotating body and disposed on the output side of the rotational driving force;
An elastic member for applying an elastic force along a rotation direction between the first rotating body and the second rotating body;
Detecting means for detecting a phase difference in rotation angle between the first rotating body and the second rotating body;
With
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.   The detecting means optically detects the first and second rotation angle detectors provided in a fan shape on the first rotating body and the second rotating body, respectively, to thereby perform the first rotation. The torque detection device according to claim 1, wherein a phase difference in rotational angle between a body and the second rotating body is detected.   The elastic member is disposed on a rotation shaft of the first rotating body or the second rotating body, and one end 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, comprising a torsion spring that is provided. An image forming means that is rotationally driven by a drive source;
A torque detecting means that is disposed between the drive source and the image forming means and detects a load torque acting on the image forming means;
With
An image forming apparatus using the torque detection device according to claim 1 as the torque detection unit.

Images