JP4522099B2 - Drive control device - Google Patents

Description

  The present invention relates to a drive control device that includes a motor for driving a moving body and a movement detection unit that detects the amount of movement of the moving body, and controls the driving of the motor based on information from the movement detection unit. is there.

  A projection lens having a zoom function generally includes a zoom lens group that moves in the optical axis direction during zooming and a focus lens group that moves in the optical axis direction during focusing. The projection lens is provided with a gear train on the outer periphery of a cam cylinder that rotates about the same axis and a lens holding cylinder that includes a moving lens. One first gear train has a first output gear for inputting zoom motor drive during zooming, and the other second gear train has a second output for inputting focus motor drive during focusing. The gears are engaged with each other. The first and second gear trains are engaged with the first and second detection gears at positions different from the engagement positions of the first and second output gears. The rotation obtained from the first and second detection gears is input to the first and second encoders. The first encoder detects the rotation angle of one cam cylinder, and the second encoder detects the rotation angle of the other cam cylinder. Each encoder sends a detection signal to the control unit, and the control unit controls driving of each motor based on each detection signal.

  In addition, the motor for zooming and focusing is shared by one motor, and the output gear fixed to the output shaft of the motor is moved between the meshing position of the first gear train and the meshing position of the second gear train. A projector provided with means is also known (Patent Document 1). This switching means moves the output gear using the drive of the solenoid. In this case, since the output gear is moved, the driving of a single motor cannot be transmitted to each of the zoom system and the focus system at the same time.

JP 2000-206400 A

  By the way, in the former drive control device, the drive of the motor is transmitted to the first and second output gears around the first or second gear train, respectively, and the first and second output gears are transmitted to the first and second gears. It is necessary to place a total of four shafts, two shafts for holding each in the meshed position with the gear train, and two shafts for supporting the first and second detection gears, respectively. For this reason, in order to attach the drive control device, a space around the gear train, particularly a space along the circumferential direction in which the gear train is arranged, is widely used, so that the projection lens has been enlarged. Further, in the latter device (the device described in Patent Document 1), since the operations of zooming and focusing are performed by driving a single motor, the number of axes can be reduced by one, whereas switching is performed instead. Since a means is needed, the space for attaching reversely is needed. In addition, there is a drawback that it cannot be used for a projection lens that simultaneously performs zooming and focusing operations.

  The present invention is for solving the above-described problems, and an object thereof is to provide a drive control device that can be made compact.

In order to achieve the above object, the zoom lens barrel drive detection device of the present invention has a first gear train on the outer periphery, and the zoom motor drive meshes with the first gear train at the time of zooming. A first rotating cylinder that rotates by being input to one output gear and moves the first lens unit of the variable power system in the optical axis direction; a second gear train that is parallel to the first gear train on the outer periphery; When the focus is driven, the driving of the focusing motor is input to the second output gear meshing with the second gear train, so that it rotates coaxially with respect to the first rotating cylinder and the second lens group of the focusing system is moved to the optical axis. A second rotating cylinder that moves in a direction; and is rotatably supported at a different position on the axis of the second output shaft to which the second output gear is fixed, and at a position different from the first output gear. A first detection gear meshing with the first gear train; a first output gear fixed to the first output gear; A second detection gear that is rotatably supported at different positions on the output shaft, and meshes with the second gear train at a position different from the second output gear; from the first and second detection gears; And a first encoder for detecting a rotation amount and a rotation direction of the first and second rotary cylinders, respectively, and based on a detection signal obtained from the first and second encoders. Thus, the drive of the zoom motor and the focus motor is controlled .

  As an encoder, you may comprise with the impeller provided in the detection gear, and the sensor which detects the slit of an impeller. When using a one-phase or two-phase output type rotary encoder, each of the first and second detection gears is a two-stage gear, and a large gear meshing with the first and second gear trains, Comprises first and second intermediate gears respectively meshing with different small gears, and first and second input shafts rotating together with the first and second intermediate gears, and the first and second input shafts Each rotation may be input to the first and second rotary encoders.

  In addition, when a pair of motors and encoders are juxtaposed on one side with the first and second gear trains interposed therebetween, the space between the axes increases in the gear train direction, and a wide arrangement space is required. Therefore, the first and second motors are arranged on one side of the first and second gear trains, and the first and second encoders are arranged on the other side so that the motor and the encoder are opposed to each other and are compact. You may make it plan.

In the present invention, the first detection gear that meshes with the first gear train at a position different from the first output gear is rotatably supported at a different position on the axis of the second output shaft to which the second output gear is fixed. In addition, the second detection gear meshing with the second gear train at a position different from the second output gear is rotatably supported at a different position on the first output shaft to which the first output gear is fixed. Therefore, the first output gear meshing with the first gear train and the second detection gear meshing with the second gear train are coaxial, and the second output gear and the first gear meshing with the second gear train The first detection gears meshing with the rows can be arranged coaxially . For this reason, space saving can be achieved. Further, space can be further saved by arranging the motor and the encoder so as to face each other.

  The projection lens 8 using the present invention includes a plurality of lens groups, a drive control device 9, a zoom lens moving mechanism, and a focus lens moving mechanism, as shown in FIG. The zoom lens moving mechanism includes a cam cylinder 11 provided with a first gear train 10 on the outer periphery, a fixed first rectilinear cylinder 12, a first lens holding cylinder 13 that holds a zoom lens group, and the like. At the time of zooming, the drive of the zoom motor 14 is input to the first gear train 10 so that the cam cylinder 11 rotates, and the cam cylinder 11 rotates so that the cam pin 15 provided on the first lens holding cylinder 13 is the cam cylinder. The first lens holding cylinder 13 is moved in the direction of the optical axis by being guided by the intersection of the cam 16 provided in 11 and the linear guide opening 17 provided in the first linear cylinder 12.

  The focusing lens moving mechanism includes a second lens holding cylinder 19 that holds a focusing lens group, and the second lens holding cylinder 19 is provided with a second gear train 18 on the outer periphery. At the time of focusing, the driving of the focusing motor 22 is input to the second gear train 18 so that the second lens holding cylinder 19 moves in the optical axis direction while rotating. The first and second gear trains 10 and 18 are arranged close to each other along the rotation axis direction of the cam cylinder 11 and the second lens holding cylinder 19.

  The drive control device 9 is roughly divided into two mechanisms as shown in FIG. One mechanism is a mechanism for inputting the drive of the zoom motor 14 to the first gear train 10 and detecting the rotation amount of the second gear train 18. The zoom motor 14, the first output shaft 26, the second It comprises a detection gear 27, a spacer 28, a first output gear 29, a second intermediate gear 30, a spacer 31, a second input shaft 32, and a second encoder 33.

  The other mechanism is a mechanism that inputs the drive of the focusing motor 22 to the second gear train 18 and detects the rotation amount of the first gear train 10. The focusing motor 22, the second output shaft 34, the first It comprises a detection gear 35, a spacer 36, a second output gear 37, a first intermediate gear 38, a spacer 39, a first input shaft 40, and a first encoder 41. The drive control device 9 is configured such that these components are integrated into the support plate 42 shown in FIG. 1 and unitized to be handled as a single component. The support plate 42 is formed in a U-shaped cross-section with the open side facing upward, and an opening 42a that exposes the first and second gear trains 10 and 18 is provided on the bottom surface. Note that the drive control device 9 integrally incorporated in the support plate 42 may be incorporated in a box-type box 60 (see FIG. 1) having an open bottom.

  The first output shaft 26 is exposed in the case 43 of the zoom motor 14. The case 43 incorporates a reduction gear train to which the drive of the motor 14 is input, and the drive output from the reduction gear train is transmitted to the first output shaft 26. A first output gear 29 is fixed to the first output shaft 26 at the front end, and a second detection gear 27 is supported at the rear end so as to be free to rotate. The first output gear 29 meshes with the first gear train 10, and the second detection gear 27 meshes with the second gear train 18. Therefore, the drive of the zoom motor 14 is input to the first gear train 10. The spacer 28 maintains a distance between the first output gear 29 and the second detection gear.

  The second detection gear 27 is a two-stage gear including a large gear 44 and a small gear 45, and the large gear 44 meshes with the second gear train 18. The second input shaft 32 is arranged in parallel with the first output shaft and is rotatably supported by the support plate 42. A second intermediate gear 30 is fixed to the second input shaft 32, and a small gear 45 meshes with the second intermediate gear 30. The second input shaft 32 is an input shaft of the second encoder 33, and the rotation of the second gear train 18 is input to the second encoder 33. The spacer 31 prevents the second intermediate gear 30 from coming off in one of the axial directions of the second input shaft 32. In the second intermediate gear 30, one side surface opposite to the contact surface of the spacer 31 is in contact with the side surface of the large gear 44, and the other intermediate gear 30 is prevented from coming off to the other side.

  The focusing motor 22 has the same configuration as that for zooming, and the second output shaft 34 is exposed to the case 46. The second output shaft 34 is transmitted with the drive output from the reduction gear train built in the case 46. A second output gear 37 is fixed to the rear end of the second output shaft 34, and a first detection gear 35 is supported at the front end of the second output shaft 34 so as to be idle. The second output gear 37 meshes with the second gear train 18, and the first detection gear 35 meshes with the first gear train 10. The driving of the focusing motor 22 is input to the second gear train 18. The spacer 36 maintains a distance between the second output gear 37 and the first detection gear 35.

  The first detection gear 35 is a two-stage gear including a large gear 47 and a small gear 48, and the large gear 47 meshes with the first gear train 10. The first input shaft 40 is arranged in parallel with the second input shaft 32 and is rotatably supported by the support plate 42. A first intermediate gear 38 is fixed to the first input shaft 40, and a small gear 48 of the first detection gear 35 meshes with the first intermediate gear 38. The first input shaft 40 is an input shaft of the first encoder 41, and the rotation of the first gear train 10 is input to the first encoder 41. The spacer 39 prevents the first intermediate gear 38 from coming off in one of the axial directions of the first input shaft 40. In the first intermediate gear 38, one side surface opposite to the contact surface of the spacer 39 is in contact with the side surface of the large gear 47, and the contact to the other side is prevented.

  The zoom and focus motors 14 and 22 are disposed on one side of the first and second gear trains 10 and 18. The first and second encoders 41 and 33 are arranged on opposite sides of the zoom and focus motors 14 and 22 with the first and second gear trains 10 and 18 interposed therebetween. Thus, by arranging the motors 14 and 22 and the encoders 33 and 41 so as to face each other, the first and second output shafts 26 and 34 and the first and second input shafts 40 and 32 can be disposed close to each other, and the gears are arranged. Compactness in the direction along the rows 10 and 18 can be achieved.

  The encoders 41 and 33 are two-phase output type rotary encoders, and signals output from the first and second encoders 41 and 33 are input to the control unit 50. Based on these signals, the control unit 50 determines the rotation angle and the rotation direction, and checks the rotation positions of the cam cylinder 11 and the second lens holding cylinder 19 based on the calculated rotation angle and rotation direction. The driving of the zooming or focusing motors 14 and 22 is controlled via this.

  The operation of the above configuration will be described. When zooming, the zoom motor 14 starts to be driven. This drive is transmitted in the order of the first output shaft 26, the first output gear 29, and the first gear train 10. At this time, the second detection gear 27 does not rotate with respect to the first output shaft 26.

  When the drive is transmitted to the first gear train 10, the cam cylinder 11 rotates. As the cam cylinder 11 rotates, the cam pin 15 is guided to the intersection of the cam 16 and the straight guide opening 17 so that the first lens holding cylinder 13 moves in the optical axis direction and the projection lens 8 is zoomed.

  At this time, the first detection gear 35 rotates following the cam cylinder 11, that is, the first gear train 10 around the second output shaft 34. This rotation is input to the first encoder 41 via the first intermediate gear 38 and the first input shaft 40. The control unit 50 controls driving of the zoom motor 14 based on a signal output from the first encoder 41.

  When focusing, the focus motor 22 starts to be driven. This drive is transmitted in the order of the second output shaft 34, the second output gear 37, and the second gear train 18. At this time, the first detection gear 35 does not rotate with respect to the second output shaft 34.

  When driving is transmitted to the second gear train 18, the second lens holding cylinder 19 rotates, the second lens holding cylinder 19 moves in the optical axis direction, and the projection lens 8 is focused.

  At this time, the second detection gear 27 rotates following the second lens holding cylinder 19, that is, the second gear train 18 around the first output shaft 26. This rotation is input to the second encoder 33 via the second intermediate gear 30 and the second input shaft 32. The signal output from the second encoder 33 is captured by the control unit 50, and the control unit 50 controls the driving of the focus motor 22 based on the captured signal. The second gear train 18 has an optical axis so that the engagement with the second output gear 37 and the second detection gear 27 is not released even if the second lens holding cylinder 19 moves in the optical axis direction. The width along the direction is long. Further, depending on the lens configuration of the projection lens 8, both the variable power lens group and the focus lens group may be moved simultaneously during zooming or focusing. In this case, both motors 14 and 22 are driven simultaneously, and the driving is controlled.

  As described above, the second detection gear 27 for extracting the rotation for feedback from the other gear train 18 can be freely rotated on the output shaft 26 that inputs the drive to one of the two gear trains 10 and 18. Since it is supported, a shaft for separately supporting the second detection gear 27 can be omitted, the cost can be reduced, and the second detection gear 27 can be arranged in a narrow space.

In the above embodiment, since the rotary encoders 33 and 41 are used, the intermediate gears 30 and 38 and the input shafts 32 and 40 are used. It is good also as a structure which detects the rotation angle of the cam cylinder 11 and the 2nd lens holding | maintenance cylinder 19 by attaching 35 to one gear and attaching an impeller to this and detecting the slit of an impeller with a photoelectric sensor. .

  The output shafts 26 and 34 are configured to transmit the drive of the motors 14 and 22 via the reduction gears. However, a motor that does not incorporate the reduction gears is used, and the motor output shaft is used as it is. It may be used.

  Furthermore, in this embodiment, the cam cylinder 11 and the second lens holding cylinder 19 juxtaposed along the rotation axis direction are used to rotate the rotating bodies, respectively. It may be a drive control device for linearly controlling the movement of each movable body provided with a gear train (rack).

  In the present embodiment, the device is configured to drive and control the rotation of the rotary cylinder provided in the projection lens. The present invention can be adopted for any mechanism.

It is a perspective view which shows the principal part of the projection lens which employ | adopted this invention. It is a disassembled perspective view which shows a drive control apparatus.

8 projection lens 9 drive control device 26 first output shaft 29 first output gear 30 second intermediate gear 33 second encoder 34 second output shaft 37 second output gear 38 first intermediate gear 40 first input shaft 41 first encoder

Claims (3)

A first gear train is provided on the outer periphery. When zooming, the zoom motor drive is input to a first output gear meshing with the first gear train to rotate and light the first lens unit of the zooming system. A first rotating cylinder moved in the axial direction;
A second gear train that is parallel to the first gear train is provided on the outer periphery, and the drive of the focusing motor is input to a second output gear that meshes with the second gear train at the time of focusing. A second rotating cylinder that rotates coaxially to move the second lens group of the focusing system in the optical axis direction;
The first detection is such that the second output gear is rotatably supported at different positions on the axis of the second output shaft to which the second output gear is fixed, and meshes with the first gear train at a position different from the first output gear. With gear,
A second detection in which the first output gear is rotatably supported at a different position on the axis of the first output shaft to which the first output gear is fixed, and meshes with the second gear train at a position different from the second output gear. With gear,
First and second encoders that respectively receive rotations from the first and second detection gears and detect rotation amounts and rotation directions of the first and second rotating cylinders ;
And a zoom lens barrel drive control device that controls driving of the zoom motor and focus motor based on detection signals obtained from the first and second encoders. The first and second detection gears are each composed of two-stage gears, and first and second intermediate gears meshed with small gears different from the large gears meshed with the first and second gear trains, respectively. And first and second input shafts rotating together with the first and second intermediate gears, respectively, so that rotations of the first and second input shafts are input to the first and second encoders, respectively. 2. The drive control device for a zoom lens barrel according to claim 1 , wherein the drive control device is configured. 3. The zoom motor and the focus motor are disposed on one side of the first and second gear trains, and the first and second encoders are disposed on the other side. The drive control device for the zoom lens barrel described.

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