JP3893611B2 - Zoom lens device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a zoom lens device, and more particularly, based on a manual operation method in which a zoom operation is performed by pushing and pulling an operation rod or a rotation operation of a zoom ring, and a zoom command signal from an operation controller such as a zoom rate demand. The present invention relates to a technique capable of removing load fluctuations due to the shape of a mechanical cam mechanism in a zoom lens apparatus that can selectively use both servo methods for zooming.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a box-type zoom lens device (EFP lens) used for a broadcast television camera, a lens operation such as a zoom operation is manually performed and a lens operation is electrically performed. As what is performed manually, an operation method called a single-axis two-operation method is known. In the uniaxial two-operation type, the zoom operation is performed by pushing and pulling the operation rod extended from the zoom lens device, and the focus operation is performed by the rotational driving force of the operation rod. In the uniaxial and two-operation type operation, the zoom position can be determined by the push-pull position of the operation rod, and since quick zoom operation is possible, it is necessary for shooting that requires instantaneous adjustment of the angle of view, such as sports broadcasting. Many are used.
[0003]
On the other hand, as a method of electrically operating the lens, an operation method called a servo method is known in which a servo motor is driven by a command signal from a dedicated controller such as a zoom rate demand and the zoom lens is driven by the driving force. Yes. This servo system is often used for shooting that requires a slow zoom operation, such as drama shooting. In the case of the servo system, it is advantageous when the zoom lens is smoothly stopped or returned to the original zoom position.
[0004]
In order to be able to select either one of the above-mentioned manual operation method of the single axis and two operation method and the servo method according to the shooting situation and the photographer's preference, both the manual operation method and the servo method are provided in one zoom lens device. A drive mechanism is proposed (Japanese Utility Model Publication No. 60-27366).
[0005]
Japanese Patent Publication No. 63-65125 discloses a technique for removing load fluctuations due to the shape of a mechanical cam mechanism by driving a motor.
[0006]
[Problems to be solved by the invention]
However, Japanese Patent Publication No. 63-65125 does not disclose a servo-type zoom operation. If the technique disclosed in Japanese Patent Publication No. Sho 63-65125 is applied to the zoom lens apparatus disclosed in Japanese Utility Model Publication No. 60-27366, the structure becomes complicated and the lens apparatus is also enlarged.
[0007]
Conventionally, a servo motor is driven by a uniaxial two-operation type operation and a zoom lens is driven by the driving force (Japanese Patent Laid-Open No. 6-230266, etc.). However, if the tilt of the operating rod changes when the lens is changed by moving the shooting direction upward or downward, the load generated by the operation rod's own weight due to the weight of the operating rod. There was also a fluctuating problem.
[0008]
The present invention has been made in view of such circumstances, and the configuration of the mechanical cam mechanism and the inclination of the lens are utilized while utilizing the current configuration of the zoom lens device capable of selectively switching between a manual operation method and a servo method. An object of the present invention is to provide a zoom lens apparatus that can realize a smooth zoom operation by removing a load fluctuation due to a temperature change. In addition, when a single-axis operation type operation rod is employed as a servo-type operation member, a zoom lens device capable of realizing a smooth zoom operation by removing load fluctuations due to the tilt of the lens (tilt of the operation rod) is provided. For the purpose.
[0013]
[Means for Solving the Problems]
To achieve the above purpose, Claim 1 In the zoom lens device that electrically moves the zoom lens by pushing and pulling the operation rod, the power generation means for generating an axial force on the operation rod, and the power generation means Load adjusting means for adjusting the load for the push-pull operation of the operating rod by controlling the force to be operated.
[0014]
According to the present invention, when a single-axis operation type operation rod is employed as a servo-type operation member, it is possible to adjust a load for a push-pull operation of the operation rod.
[0018]
Claims 2 According to the aspect described above, the load adjusting means operates to make the load heavier than the other zoom movable ranges in the vicinity of at least one of the tele end and the wide end in the zoom movable range. It is characterized by . Control If the addition becomes heavy in the vicinity of the zoom end during the operation of the stick, the cameraman can easily recognize the arrival of the zoom end and can perform a smooth stop operation at the zoom end.
[0019]
In this case, the claim To 3 As shown, Above When the zoom speed by the push-pull operation of the operating rod is faster than a predetermined determination reference speed, the zoom is operated so as to increase the load in the vicinity of the zoom end, and the zoom speed is slower than the determination reference speed. In this case, it is also preferable that the adjustment for increasing the load is not performed in the vicinity of the zoom end. When the so-called quick operation is performed, the brake is applied before the zoom end, and when the slow operation is performed, such control is not required.
[0022]
Further claims 4 As shown in FIG. 4, it is preferable that the zoom lens apparatus according to the present invention is provided with an angle detection unit that detects an inclination angle and corrects a load variation when the lens is tilted according to the angle detected by the angle detection unit.
[0023]
Claim 5 As shown, the adjustment data for adjusting the load is stored in a memory built in the zoom lens apparatus, and the load adjustment means refers to the data in the memory as necessary.
[0024]
The adjustment data may be acquired at the time of shipment adjustment at the time of shipment from the factory, or the adjustment data may be updated by automatically executing the load adjustment data measurement operation when the power is turned on. Moreover, you may make it perform load acquisition data acquisition operation | movement based on a user instruction | indication as needed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a zoom lens device according to the present invention will be described in detail below with reference to the accompanying drawings.
[0026]
The zoom lens apparatus according to the embodiment of the present invention shown in FIG. 1 and FIG. 2 is either a single-axis operation type manual method or a servo method using a controller such as a zoom rate demand or a focus position demand depending on the shooting situation and the photographer's preference. And the zoom operation and the focus operation can be performed by the selected operation method.
[0027]
FIG. 1 is a perspective view showing a television camera system when the uniaxial operation method is used, and FIG. 2 is a perspective view of the television camera system when the servo method is used.
[0028]
As shown in these drawings, the television camera 10 includes a zoom lens device 12 and a camera body 14. The zoom lens device 12 is mounted on the front side of the camera body 14 placed on the camera platform 22. As shown in FIG. 1, when the operation is performed by the uniaxial operation method, an operation rod 16 is installed on the back side of the zoom lens device 12 (surface attached to the camera body 14). Is protruded to the back side of the camera body 14 through the operation rod insertion hole 14A (see FIG. 2) formed in the camera.
[0029]
The cameraman can perform a zoom operation by grasping the finger hook portion 18 of the operation bar 16 and pushing and pulling the operation bar 16 while watching the image displayed on the viewfinder 20 installed in the camera body 14. Further, the focus operation can be performed by rotating the finger hook 18 and rotating the axis of the operation rod 16. The operation bar 16 is detachable from the zoom lens device 12.
[0030]
On the other hand, when the servo system is used, a zoom rate demand 26 and a focus position demand 28 are installed at the tips of pan / tilt bars 24A and 24B extending from the camera platform 22 as shown in FIG. From the zoom rate demand 26 and the focus position demand 28, a zoom speed command signal for instructing a zoom speed and a focus position command signal for instructing a focus position are output, respectively, and these command signals are sent to the zoom lens device 12 via a cable. Sent. The photographer can perform a zoom operation by rotating the thumb ring 26A of the zoom rate demand 26 with a thumb, and can perform a focus operation by rotating the focus knob 28A of the focus position demand 28.
[0031]
FIG. 3 is an overall configuration diagram of the zoom lens device 12. The zoom lens device 12 mainly includes a lens barrel 30, a uniaxial operation type operation unit 32, a zoom drive system switching clutch unit 34, and a control circuit 36.
[0032]
In the lens barrel 30, a focus lens 40, a variator lens 42A of a zoom system lens 42, a compensator lens 42B, and a master lens 44 are arranged in order from the front. In the focus lens 40, the lead screw 46 is screwed into the support frame 40A, and the rotational driving force of the focus servo module 48 in which the servo motor is built is transmitted from the rotation output unit 48A to the rotation input unit 50, the pulley 52, the teeth. By being transmitted to the lead screw 46 through the attached belt 54 and the pulley 56, the focus lens 40 moves back and forth along the optical axis direction. The power transmission system from the focus servo module 48 to the lead screw 46 can transmit the rotational driving force without backlash by the toothed belt 54 or the like.
[0033]
The lead screw 46 is provided with a focus position sensor (for example, a potentiometer) 58. The focus position sensor 58 detects the amount of rotation of the lead screw 46 (corresponding to the focus position of the focus lens 40), and outputs a signal indicating the focus position to the control circuit 36.
[0034]
The variator lens 42A and the compensator lens 42B constituting the zoom system lens 42 have cam pins 42C and 42D implanted in these support frames engaged with cam grooves 60A and 60B of the zoom cam 60, and the zoom cam 60 rotates. Thus, the variator lens 42A and the compensator lens 42B move back and forth along the optical axis according to the positional relationship regulated by the cam grooves 60A and 60B. The zoom cam 60 is provided with a zoom position sensor (for example, a potentiometer) 62. The zoom position sensor 62 detects the rotational position of the zoom cam 60 (corresponding to the zoom position of the zoom system lens 42), and outputs a signal indicating the zoom position to the control circuit 36.
[0035]
The operation bar 16 of the operation unit 32 is slidably inserted into a hollow shaft 64 that is rotatably supported. The hollow shaft 64 is formed with a key groove 64A in the longitudinal direction, and a pin 66 fixed to the tip of the operation rod 16 is engaged with the key groove 64A. Therefore, when the operating rod 16 is rotated, the hollow shaft 64 is rotated in conjunction with this.
[0036]
A pin 64B is disposed on one end side of the hollow shaft 64, and the pin 64B comes into contact with the stopper 68 when rotated by a predetermined amount. Thereby, the rotation range of the hollow shaft 64 (operation rod 16) is regulated. A focus command position sensor 70 is provided on the other end side of the hollow shaft 64. The focus command position sensor 70 detects the rotational position (focus command position) of the hollow shaft 64, and the focus command position. Is output to the control circuit 36 (focus position command signal).
[0037]
On the other hand, a moving frame 72 is inserted through the hollow shaft 64 so as to be movable in the axial direction, and the tip of the pin 66 of the operating rod 16 engages with a circumferential groove 72A formed on the inner periphery of the moving frame 72. is doing. A predetermined amount of the wire winding portion 80 is wound around the moving frame 72, and both ends of a wire 78 stretched through pulleys 73, 74, 75 and 76 are fixed. Therefore, when the operation rod 16 is pushed and pulled, the wire 78 moves in conjunction with this operation, and the wire winding portion 80 rotates.
[0038]
The clutch portion 34 has a first pulley 84 that is rotatably disposed around a support shaft 82 and a wire winding that is rotatably disposed on a support shaft 84A that is integrally formed with the first pulley 84. Part 80, a gear 86 fixed to the support shaft 84A, a moving ring 88 disposed so as to be movable in the axial direction of the support shaft 84A, a zoom drive system switching motor 90 for moving the moving ring 88, etc. Consists of The operation of the zoom drive switching motor 90 is controlled by the control circuit 36.
[0039]
A rotational driving force is applied to the wire winding portion 80 by a wire 78 that moves by pushing and pulling the operating rod 16. Further, the gear 86 has a rotational driving force from the rotation output unit 92A of the zoom servo module 92 incorporating a servo motor (denoted by reference numeral 128 in FIG. 6) through the rotation input unit 93, the gear 95, and the gear 96. Has been added. The gear 96 is fixed to the telescopic shaft 97A of the cylinder 97, and the gear 96 moves in the left-right direction in FIG. The operation of the cylinder 97 is controlled by the control circuit 36.
[0040]
As shown in FIG. 3, when the telescopic shaft 97 </ b> A is housed in the cylinder 97, the gear 96 moves from the meshing position with the gears 94 and 86 to the retracted position, and the connection relationship between the gear 94 and the gear 86 is separated.
[0041]
On the other hand, when the telescopic shaft 97 </ b> A is extended, the gear 96 meshes with the gears 96 and 86 to establish a connection relationship between the gears 94, 96 and 86. As a result, the rotational driving force from the zoom servo module 92 is transmitted to the gear 86. As the gear 86 rotates, the support shaft 84A and the first pulley 84 rotate in conjunction with this rotation.
[0042]
The moving ring 88 is provided with a key 88A, and this key 88A is engaged with a key groove 84B formed in the longitudinal direction of the support shaft 84A. Further, the moving ring 88 can be engaged / disengaged with the wire winding portion 80 by moving in the axial direction of the support shaft 84A. That is, one taper pin 89 is implanted on the right side surface of the moving ring 88 in FIG. 3, and one taper hole engaging with the taper pin 89 is formed on the left side surface of the wire winding portion 80. It has been drilled.
[0043]
When the moving ring 88 engages with the wire winding portion 80 and a rotational driving force is transmitted to the wire winding portion 80, the moving ring 88 rotates, and the support shaft 84A and the first pulley 84 are interlocked with this. Rotates.
[0044]
When the first pulley 84 rotates, the rotational driving force is transmitted from the first pulley 84 to the pulley 85 of the zoom cam 60 through the toothed belt 83 without backlash. The pulley 85 is fixed to the zoom cam 60, and the zoom system lens 42 is driven by the rotation of the zoom cam 60.
[0045]
The focus servo module 48 and the zoom servo module 92 are detachable from the zoom lens device 12. Instead of the servo module 48 or 92, it is possible to apply a manual module that transmits a manual rotational driving force to the rotational input unit 50 or the rotational input unit 93 via a flexible wire. Can be changed to a different manual operation system.
[0046]
Further, the control circuit 36 controls the display content of the display unit 99. The display unit 99 is used for zoom operation using the operation rod 16, focus operation using the operation rod 16, zoom operation using the zoom rate demand 26, focus operation using the focus position demand 28, and enabling / disabling of the electric assist function described later. It is a means for displaying information indicating the situation. Although a specific configuration of the display unit 99 is not illustrated, a liquid crystal display panel, a light emitting diode (LED), or a combination thereof can be applied to the display unit 99. The photographer can easily confirm the current usage status by viewing the display on the display unit 99.
[0047]
A gear 91 is fixed to the shaft of the zoom drive switching motor 90, and a bearing 100 is provided at an eccentric position of the gear 91. The bearing 100 abuts on a groove 88 </ b> B formed on the outer periphery of the moving ring 88 and can rotate as the moving ring 88 rotates.
[0048]
The gear 102 meshed with the gear 91 is always rotated clockwise (CW direction) or counterclockwise (CCW direction) by a coil spring 104 according to the rotation position of the gear 102 (rotation position of the zoom drive switching motor 90). Direction) is applied.
[0049]
FIG. 4 is an arrow view of the main part when the gear 91 and the like are viewed from the direction of arrow A in FIG. In FIG. 4, the gear 102 is biased in the CW direction by the coil spring 104, and as a result, the gear 91 is biased in the CCW direction. The bearing 100 provided at the eccentric position on the lower surface side of the gear 91 abuts on the right side surface of the groove 88B of the moving ring 88 as shown by the dotted line, and moves the moving ring 88 in the right direction and urges it in the right direction. To do. Thereby, the moving ring 88 is engaged with the wire winding portion 80 with a predetermined urging force.
[0050]
On the other hand, when the zoom drive switching motor 90 is operated to rotate the gear 91 in the CW direction in FIG. 4 and the coil spring 104 urging the gear 102 reaches the position indicated by the dotted line, the coil spring 104 causes the gear 102 to move. As a result, the gear 91 is urged in the CW direction. At this time, the bearing 100 provided at the eccentric position on the lower surface side of the gear 91 abuts on the left side surface of the groove 88B of the moving ring 88 as shown by a one-dot chain line, and moves the moving ring 88 leftward and left. Energize in the direction. As a result, the moving ring 88 is disengaged from the wire winding portion 80, and the unconnected state is maintained with a predetermined urging force.
[0051]
Reference numeral 106 denotes a changeover switch that is operated by a protrusion 102A that rotates together with the gear 102. The changeover switch 106 detects whether the zoom operation has been switched to the uniaxial manual side or the servo side. That is, the changeover switch 106 is turned on in the state shown in FIG. 4 (the state in which the moving ring 88 is engaged with the wire winding portion 80), and outputs a signal indicating that the switch has been switched to the manual side to the control circuit 36. When the moving ring 88 is detached from the wire winding portion 80, the switch is turned off, and a signal indicating that switching to the servo side is output to the control circuit 36.
[0052]
FIG. 5 is an enlarged view of the main part of the right side surface of the moving ring 88 and the left side surface of the wire winding portion 80. As shown in the figure, one taper pin 89 is implanted on the right side surface of the moving ring 88, and one taper that engages with the taper pin 89 is arranged on the left side surface of the wire winding portion 80. A hole 81 is formed.
[0053]
The taper pin 89 has a composite structure of a taper pin main body 89A made of a metal material and a tip portion 89B made of a lubricating material. Therefore, the taper pin 89 slides in contact with the side surface of the wire winding portion 80 until it engages with the taper hole 81 of the wire winding portion 80, but the sliding operation is performed smoothly. Can do. Further, the taper pin 89 can be engaged with the taper hole 81 without backlash, and the moving ring 88 and the wire winding portion 80 are engaged only when they are in a predetermined rotational positional relationship.
[0054]
The reason why the movable ring 88 and the wire winding portion 80 can be engaged only when they are in a predetermined rotational positional relationship is to prevent the relationship between the position of the operation rod 16 and the zoom position from changing.
[0055]
FIG. 6 is a block diagram showing a configuration related to the control system of the zoom lens device 12. In FIG. 6, parts that are the same as those described in FIG. 3 are given the same reference numerals. The control circuit 36 receives signals indicating the current focus position and zoom position from the focus position sensor 58 and zoom position sensor 62, respectively.
[0056]
A zoom speed command signal for instructing the zoom speed is added from the zoom controller 120 (corresponding to the zoom rate demand 26), and a focus position command signal for instructing the focus position from the focus controller 122 (corresponding to the focus position demand 28). Is added.
[0057]
The servo / uniaxial selection means 124 is a means for selecting whether to operate the zoom lens device 12 by the servo system or the manual system by the operation rod 16, and appropriately switches the servo / uniaxial depending on the photographer's preference. Can do. The select signal of the servo / single axis selecting means 124 is input to the control circuit 36, and the control circuit 36 performs control according to the select signal.
[0058]
The memory 126 stores data for load adjustment (electric assist). Load information is actually measured by measuring the current of the servo motor 128 during zoom operation at the time of factory shipment, and the load adjustment data obtained based on the information is stored in the memory 126. Note that the load adjustment data is not limited to the case where it is acquired at the time of shipment adjustment, and the adjustment data may be updated by automatically executing the operation of measuring the load adjustment data when the zoom lens device 12 is turned on. Further, the load adjustment data acquisition operation may be executed by a user performing a predetermined operation as necessary.
[0059]
When the electric assist function is activated, the control circuit 36 refers to the data in the memory 126 and performs load adjustment control during manual operation.
[0060]
The torque setting means 130 is a means for setting the magnitude of the zoom operation load during manual operation. For example, the control circuit 36 is configured to be able to switch between three stages (heavy / medium / light), and the control circuit 36 adjusts the load level according to the setting of the torque setting means 130.
[0061]
The zoom lens device 12 includes a temperature sensor 132 and an angle sensor 134, and detection signals from the sensors are input to the control circuit 36. The temperature sensor 132 measures the temperature of the environment in which the zoom lens device 12 is used. Since the load during zoom operation changes depending on the temperature (generally, the load becomes lighter as the temperature increases), it is used for load adjustment control corresponding to the temperature change. The tilt angle of the zoom lens device 12 is detected by the angle sensor 134. Since the load during the zoom operation varies depending on the tilt angle of the zoom lens device 12, load adjustment control according to the change in tilt angle is performed. Data necessary for load adjustment in consideration of such temperature and tilt angle is stored in the memory 126 in the zoom lens device 12.
[0062]
The clutch switching drive circuit 136 outputs a drive signal for operating the zoom drive switching motor 90 and the cylinder 97 in accordance with a command from the control circuit 36.
[0063]
When the servo method is selected by the servo / single axis selection means 124, the select signal is input to the control circuit 36. The control circuit 36 validates the input signals from the zoom controller 120 and the focus controller 122, and the focus command position. The input signal from the sensor 70 is invalidated. At this time, the control circuit 36 outputs a servo switching command signal to the clutch switching drive circuit 136. As a result, the zoom drive switching motor 90 operates to set the clutch portion 34 to the servo side, and the cylinder 97 operates. Thus, the interlocking relationship between the operating rod 16 and the cam mechanism (zoom cam 60) of the zoom lens 42 is separated, and the power of the servo motor 128 for driving the zoom is a clutch portion 142 including the gear 96 (hereinafter referred to as a servo clutch). Can be transmitted to the cam mechanism via the.
[0064]
In this state, when the cameraman operates the operation unit of the zoom controller (corresponding to the zoom rate demand 26), a speed instruction signal for instructing the zoom speed is applied from the zoom controller 120 to the control circuit 36. The control circuit 36 outputs a control signal to the zoom drive circuit 140 based on the zoom speed command signal and a signal indicating the current zoom position applied from the zoom position sensor 62 to drive the servo motor 128.
[0065]
When the rotational driving force of the servo motor 128 is transmitted to the zoom cam 60 via the servo clutch 142, the zoom cam 60 rotates and the zoom lens 42 is servo-driven. The servo motor 128 is provided with a tacho generator 144, and the tacho generator 144 generates a voltage signal corresponding to the rotation speed of the servo motor 128. A signal from the tacho generator 144 is supplied to the control circuit 36 and the zoom drive circuit 140. At this time, a generated voltage is also generated from the servo motor 128, and a signal indicating the generated voltage of the servo motor 128 is fed back to the control circuit 36 and the zoom drive circuit 140. The servo motor 128, the tacho generator 144, and the zoom drive circuit 140 are incorporated in the zoom servo module 92 shown in FIG.
[0066]
When the cameraman operates the operation unit of the focus controller 122 (corresponding to the focus position demand 28) with the servo system selected, a focus position command signal is output from the focus controller 122. The control circuit 36 outputs a control signal to the focus drive circuit 150 based on the focus position command signal and a signal indicating the current focus position applied from the focus position sensor 58, and the focus lens 40 changes the focus position command signal. The servo motor 152 for driving the focus is controlled so that the corresponding focus position is obtained.
[0067]
The servo motor 152 is provided with an tacho generator 154, and the tacho generator 154 generates a voltage signal corresponding to the rotation speed of the servo motor 152. A signal from the tacho generator 154 is supplied to the control circuit 36 and the focus drive circuit 150. At this time, a generated voltage is also generated from the servo motor 152, and a signal indicating the generated voltage of the servo motor 152 is fed back to the control circuit 36 and the focus drive circuit 150. Thus, the focus lens 40 is servo-driven in accordance with a command from the focus controller 122.
[0068]
When the one-axis method is selected by the servo / one-axis selection unit 124, the control circuit 36 invalidates the input signals from the zoom controller 120 and the focus controller 122 and detects from the focus command position sensor 70 that detects the rotation of the operation rod 16. The input signal is valid. At this time, the control circuit 36 outputs a switching command signal to the single-axis system to the clutch switching drive circuit 136.
[0069]
Thereby, the zoom drive switching motor 90 operates to connect the clutch portion 34 to the manual side, and the interlocking relationship between the operation rod 16 and the cam mechanism (zoom cam 60) of the zoom lens 42 is established. In this way, a zoom operation by pushing and pulling the operation rod 16 becomes possible.
[0070]
The assist presence / absence switching means 156 is a means for switching whether or not to perform load adjustment control (electric assist) for the zoom operation during manual operation by the operation rod 16. A switching signal from the assist presence / absence switching means 156 is input to the control circuit 36, and the control circuit 36 outputs a control signal to the clutch switching drive circuit 136 according to the received switching signal to control the operation of the cylinder 97.
[0071]
In the case of performing load adjustment control (with assist), torque is added by the servo motor 128 (electric assist) by connecting the clutch portion (servo clutch) 142 of the servo motor 128 during one-axis operation. On the other hand, when the load adjustment control is not performed (no assist), the servo clutch 142 is released during the single-axis operation, and the torque addition by the servo motor 128 is not performed.
[0072]
The servo / uniaxial selection unit 124, the torque setting unit 130, the assist presence / absence switching unit 156, and the zoom lens device 12 may be provided in the main body, or may be provided in a controller installed at the hand of the cameraman. Good.
[0073]
FIG. 7 is a graph illustrating an example of load characteristics of the zoom lens device 12. The load fluctuation characteristic curve at the zoom ratio as shown in FIG. Information on the load variation characteristic for the entire zoom operation range from the wide end to the tele end is stored in the memory 126, and the control circuit 36 refers to the data in the memory 126 and outputs a zoom drive control signal for electric assist. Output to the zoom drive circuit 140. Since the load variation characteristic is also affected by the temperature and the tilt angle of the lens, the load variation characteristic data at the temperature and the tilt angle is stored in the memory 126 as a table or as an arithmetic expression.
[0074]
Next, the operation of the zoom lens device 12 configured as described above will be described.
[0075]
FIG. 8 is a flowchart of a main routine of operation control in the zoom lens device 12 of the present example. As shown in the figure, the control circuit 36 of the zoom lens apparatus 12 first executes a uniaxial / servo setting process (step S110), and then executes a zoom process (step S112) and a focus process (step S114). To do.
[0076]
After the focus processing, other necessary operation processing (for example, iris processing, extender processing, view angle correction processing, etc.) is performed, and the process returns to step S110.
[0077]
FIG. 9 is a flowchart showing a subroutine for single axis / servo processing. When the one-axis / servo processing is started, the control circuit 36 reads the select signal from the servo / one-axis selection means 124 (step S210).
[0078]
After reading the select signal, the operation method is determined (step S212). When the servo system is selected, the process proceeds to step S214. In step S214, processing for releasing the zoom drive system switching clutch section 34 (hereinafter referred to as a single-axis clutch) is executed, and this subroutine is terminated.
[0079]
If the single axis method is selected in step S212, the process proceeds to step S216, and a process for engaging the single axis clutch is performed. Thereafter, whether the assist function is valid / invalid is determined based on the assist presence / absence switching signal (step S218). When “no assist” is selected, the process of releasing the servo clutch 142 is executed (step S220), while when “with assist” is selected in step S226, the process of connecting the servo clutch 142 is executed. (Step S222), and this subroutine is finished.
[0080]
FIG. 10 is a flowchart showing the zoom processing procedure. When the zoom process starts, the control circuit 36 reads a zoom position signal from the zoom position sensor 62 (step S310). Next, the operation method is determined (step S312). When the servo method is selected, the process proceeds to step S314, and an instruction signal from the zoom controller 120 is read. Then, normal zoom driving data is created in accordance with the instruction signal (step S316).
[0081]
On the other hand, when the uniaxial operation method is selected in step S312, the process proceeds to step S320. In step S320, the voltage value of the servo motor 128 is read. Further, the voltage of the tacho generator 144 is read (step S322), the angle sensor value is read (step S324), the temperature sensor value is read (step S326), and the torque setting value is read (step S328).
[0082]
Then, zoom drive data for electric assist is created based on the read information (step S330). In step S330, the cam information corresponding to the zoom position is acquired from the memory, and zoom drive data considering the angle, temperature, and torque setting information is created.
[0083]
After step S330 or step S316, zoom drive data is output to the zoom drive circuit 140 (step S332), and this subroutine is terminated.
[0084]
FIG. 11 is a flowchart showing the procedure of focus processing. When the focus process starts, the control circuit 36 reads a focus position signal from the focus position sensor 58 (step S410). Next, the operation method is determined (step S412). When the servo system is selected, the process proceeds to step S414, and the instruction signal from the focus controller 122 is read.
[0085]
On the other hand, when the uniaxial operation method is selected in step S412, the focus control signal (FCTRL) is read from the focus command position sensor 70 provided on the operation rod 16 (step S416). After step S416 or step S414, the process proceeds to step S418, and normal focus drive data is created based on the read instruction signal or focus control signal. The generated focus drive data is output to the focus drive circuit 150, and this subroutine is terminated.
[0086]
In the above embodiment, the load variation for the entire zoom operation range from the wide end to the tele end is corrected so that the zoom operation during manual operation can be performed smoothly, but as a modification of the present embodiment, By using the assist function, it is possible to perform a control for increasing the load of the zoom operation near the wide end and the tele end. By performing control to increase the load in the vicinity of the zoom end during manual operation, the cameraman can be aware of the arrival of the zoom end during the zoom operation, and can smoothly stop at the zoom end.
[0087]
Such load adjustment near the zoom end is particularly effective when the zoom speed is high (during quick operation), and is therefore a reference for determining whether or not to perform load adjustment near the zoom end. A zoom speed (referred to as “judgment reference speed”) is determined in advance, and when the zoom speed at the time of operation is larger than the predetermined judgment reference speed, control is performed to increase the load before the zoom end. It is also preferable that the load adjustment control before the zoom end is not performed when the zoom speed is lower than the determination reference speed.
[0088]
In the above embodiment, an example in which the present invention is applied to a uniaxial zoom lens apparatus using an operating rod has been described. However, the scope of the present invention is not limited to this, and a zoom ring formed on a lens barrel is hand-held. The present invention can also be applied to a zoom lens apparatus that employs a manual system that is rotated by operation.
[0089]
In the above-described embodiment, the electric assist function in the case where the uniaxial operation type operation rod 16 is used as a manual operation member has been described. However, the uniaxial operation type operation rod 16 is used as a servo operation member. Even in this case, the electric assist function can be applied in exactly the same manner. Hereinafter, a configuration for enabling the electric assist function when the uniaxial operation type operation rod 16 is used as a servo operation member will be described.
[0090]
FIG. 12 is a block diagram showing a configuration relating to the control system of the zoom lens device 12 when the uniaxial operation type operation rod 16 installed as in FIG. 1 is used as a servo operation member. In the uniaxial operation type operation unit 230 shown in the figure, the operation rod 16 is slidably inserted into a hollow shaft 240 rotatably supported. The hollow shaft 240 is formed with a key groove hole 240A along the longitudinal direction, and a pin 242 fixed to the tip of the operation rod 16 is engaged with the key groove hole 240A. When the operation rod 16 is rotated, the hollow shaft 240 is rotated in conjunction with the operation rod 16.
[0091]
A moving frame 244 is fitted on the hollow shaft 240, and the tip of the pin 242 is engaged with a circumferential groove 244 </ b> A formed on the inner periphery of the moving frame 244. A part of the belt 248 wound around the pulleys 246A and 246B is fixed to the convex portion 244B of the moving frame 244. When the operation rod 16 is pushed and pulled, the pulleys 246A and 246B are rotated in conjunction with this operation.
[0092]
The pulley 246 </ b> A is attached to the rotation shaft 250 </ b> A of the zoom command position sensor 250, and the rotation position of the pulley 246 </ b> A corresponding to the push / pull position of the operation rod 16 is detected by the zoom command position sensor 250. The detection signal output from the zoom command position sensor 250 is input to the control circuit 260. The control circuit 260 acquires the detection signal as a zoom position command signal indicating a zoom target position corresponding to the push / pull position of the operation rod 16.
[0093]
On the other hand, the pulley 246B is attached to the rotating shaft 254A of the motor 254, and the motor 254 generates a torque having a predetermined magnitude and direction in the pulley 246B by a voltage (current) applied from the control circuit 260. Thus, a load having a desired size and direction can be applied to the axial direction of the operating rod 16 through the belt 248 and the like, and the same control as the above-described electric assist function can be performed.
[0094]
The rotation shaft 252A of the focus command position sensor 252 is engaged with the peripheral surface of the end portion of the hollow shaft 240 via a gear, and the rotation position of the hollow shaft 240 according to the rotation position of the operation rod 16 is focused. It is detected by the command position sensor 252. The detection signal output from the focus command position sensor 252 is input to the control circuit 260. The control circuit 260 acquires the detection signal as a focus position command signal indicating a focus target position corresponding to the rotational position of the operation rod 16.
[0095]
On the other hand, in the optical system of the zoom lens device 12, a focus lens 270, a variator lens 272A of the zoom system lens 272, a compensator lens 272B, and the like are arranged in order from the front as in the above embodiment. The support frame 274 of the focus lens 270 is connected to a lead screw 276, and the focus lens 270 moves back and forth along the optical axis P when the lead screw 276 is rotated by the focus motor 278.
[0096]
The zoom lens 272 includes a variator lens 272A and a compensator lens 272B, and cam pins 272C and 272D projecting from the support frames of the lenses are engaged with cam grooves 280A and 280B of the cam barrel 280, respectively. When the cam cylinder 280 is rotated by the zoom motor 282, the variator lens 272A and the compensator lens 272B move back and forth along the optical axis P according to the positional relationship regulated by the cam grooves 280A and 280B.
[0097]
The control circuit 260 detects the position (focus position) of the focus lens 270 with the focus position sensor 284 installed on the lead screw 76, and the position (zoom position) of the zoom lens 272 with the zoom position sensor 286 installed on the cam cylinder 280. ), The focus motor 278 and the zoom motor 282 are driven, and the focus lens 270 and the zoom lens 272 are servo-controlled.
[0098]
That is, the control circuit 260 adjusts the focus so that the difference between the focus target position indicated by the focus position command signal received from the focus command position sensor 252 of the operation unit 230 and the focus position detected by the focus position sensor 284 becomes zero. The focus lens 270 is moved by drivingly controlling the motor 278. The control circuit 260 zooms so that the difference between the zoom target position indicated by the zoom position command signal received from the zoom command position sensor 250 of the operation unit 230 and the zoom position detected by the zoom position sensor 286 becomes zero. The zoom lens 272 is moved by drivingly controlling the motor 282.
[0099]
According to the zoom lens device 12 configured as described above, by controlling the torque of the motor 254, it is possible to generate a required load for the push-pull operation of the operation rod 16, so in the above embodiment. It is easily possible to execute the described electric assist function. For example, in the operation rod 16 that is a servo-type operation member, the load fluctuation with respect to the push-pull operation is considered to be largely due to the tilt of the zoom lens device 12, that is, the tilt of the operation rod 16, so FIG. As shown, an angle sensor 256 is installed in the zoom lens device 12 (or the operation unit 230), and a detection signal from the angle sensor 256 is input to the control circuit 260. In this case, from the angle sensor 256, as shown in FIG. 13, an angle θ formed by an in-plane direction (horizontal direction) perpendicular to the gravitational direction and a reference direction of the zoom lens device 12 (axial direction of the operation rod 16). (Hereinafter referred to as an inclination angle θ) is supplied to the control circuit 260 as a detection signal. The control circuit 260 controls the torque of the motor 254 based on the inclination angle θ acquired from the angle sensor 256 and adjusts the load for the push / pull operation of the operation rod 16. By this load adjustment, regardless of the inclination of the operation rod 16, the same load as that applied to the push-pull operation of the operation rod 16 when the operation rod 16 is oriented in the horizontal direction can be given to the push-pull operation. it can. For example, the control rod 16 is controlled by controlling the magnitude and direction of the torque of the motor 254 so as to cancel the force acting in the axial direction of the control rod 16 due to gravity at the tilt angle θ detected by the angle sensor 256. It is possible to prevent the load fluctuation due to the inclination of the control rod 16 so that the operation rod 16 can be pushed and pulled with a constant load. Further, not only the load fluctuation due to gravity is prevented, but also in the same way as in the above embodiment, the load on the push / pull operation of the operating rod 16 is increased in front of the zoom end, or only when the zoom speed is a certain speed or higher. Load adjustment such as increasing the load before the zoom end can be performed. Furthermore, the magnitude of the load can be switched to, for example, three stages (heavy / medium / light) by means corresponding to the torque setting means 130.
[0100]
In addition, when the power is turned off, it is possible to use the holding torque of the motor 254 to hold the operation rod 16 so as not to slide in the axial direction due to its own weight.
[0101]
【The invention's effect】
As described above, according to the zoom lens device according to the present invention, the servo driving means mounted on the zoom lens device capable of switching the zoom operation method to the manual method or the servo method is used to perform zooming during manual operation. Since the operation load is adjusted, it is not necessary to separately provide a motor for adjusting the load, and the structure can be simplified. In addition, by utilizing the servo driving means that has not been used during manual operation, the equipment (resources) of the zoom lens device can be effectively utilized. Even when a single-axis operation type operation rod is adopted as a servo-type operation member, by generating a force in the axial direction with respect to the operation rod by a motor or the like, the push-pull operation of the operation rod can be prevented. The load can be adjusted.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the entire configuration of a television camera system when a single-axis two-operation type operation method using an operation rod is used.
FIG. 2 is a perspective view showing a configuration of the entire TV camera system when using an operation method of a zoom rate demand and a focus position demand.
FIG. 3 is an overall configuration diagram of a zoom lens device according to the present embodiment.
4 is an arrow view of the main part as seen from the direction of arrow A in FIG.
5 is an enlarged view of the main part of the right side surface of the moving ring and the left side surface of the wire winding portion shown in FIG. 3;
FIG. 6 is a block diagram showing a configuration relating to a control system of the zoom lens apparatus according to the present embodiment.
FIG. 7 is a graph showing load characteristics of the zoom lens device.
FIG. 8 is a flowchart showing an operation control procedure in the zoom lens apparatus of the present example.
FIG. 9 is a flowchart showing an operation control procedure in the zoom lens apparatus of the present example.
FIG. 10 is a flowchart showing an operation control procedure in the zoom lens apparatus of the present example.
FIG. 11 is a flowchart showing an operation control procedure in the zoom lens apparatus of the present example.
FIG. 12 is a diagram illustrating a configuration of a zoom lens device when a single-axis operation type operation rod is used as a servo-type operation member.
FIG. 13 is a diagram used for explaining the tilt angle of the zoom lens device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Television camera, 12 ... Zoom lens apparatus, 14 ... Camera body, 16 ... Operation rod, 26 ... Zoom rate demand, 30 ... Lens barrel, 32 ... Operation unit, 34 ... Clutch part, 36 ... Control circuit, 42 ... Zoom lens, 60 ... zoom cam, 62 ... zoom position sensor, 64 ... hollow shaft, 78 ... wire, 80 ... wire winding part, 90 ... zoom drive system switching motor, 92 ... zoom servo module, 97 ... cylinder, 124 ... servo / single axis selection means, 128 ... servo motor, 130 ... torque setting means, 132 ... temperature sensor, 134 ... angle sensor, 140 ... zoom drive circuit

Claims (5)

In the zoom lens device that moves the zoom lens electrically by pushing and pulling the operation rod,
Power generating means for generating an axial force on the operation rod;
Load adjusting means for controlling the force generated by the power generating means to adjust the load on the push-pull operation of the operating rod;
A zoom lens device comprising: Said load adjusting means to claim 1, characterized in that operate to heavier the load than the zoom range of motion of the rest in the vicinity of at least one of the zoom end of the telephoto end and the wide end in the zoom movable range The zoom lens device described. When the zoom speed by the push-pull operation of the operation bar is faster than a predetermined determination reference speed, the zoom is operated so as to increase the load in the vicinity of the zoom end, and the zoom speed is higher than the determination reference speed. 3. The zoom lens apparatus according to claim 2 , wherein the adjustment for increasing the load is not performed in the vicinity of the zoom end when the speed is slow. The zoom lens device according to claim 1 , wherein the device includes angle detection means for detecting an inclination angle of the zoom lens device,
The zoom lens according to claim 1, wherein the load adjusting unit corrects a load variation at the time of tilting the lens according to the angle detected by the angle detecting unit, and adjusts a load with respect to a push / pull operation of the operation rod to a certain level. apparatus. In the zoom lens system according to any one of claims 1 to 4, adjustment data for adjusting the load, zoom, characterized in that stored in the memory incorporated in the zoom lens device Lens device.

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