JPS61141414A - Lens movememt control device - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a lens movement control device and to permit the reliable control of lens movement by controlling the driving speed and driving direction of a driving means according to the inductance of a variable inductance means. CONSTITUTION:A seesaw switch 20 turns clockwise around a revolving shaft 21 when the operator pushes the switch 20 in the position of an arrow 39. A ferrite core 26 in then deeply inserted into a coil 25 by which the inductance of the coil is increased and the oscillation frequency in a control circuit 28 is decreased. The control voltage corresponding to the oscillation frequency is exerted to a motor driving circuit 30, by which a gear 33 is rotated clockwise. The ferrite core is pulled upward from the coil 25 when the operator pushes the switch 20 from an arrow 40 side. The inductance of the coil is then decreased and the oscillation frequency is increased, by which a motor 31 is rotated counterclockwise and a lens moving frame 34 is moved in the direction opposite from the arrow 38.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a lens moving operation device that can be used in a video camera.

2. Description of the Related Art In recent years, there has been a demand for a lens moving operation device that can make video cameras smaller and lighter and that can change the zoom speed of a variable magnification lens with easy operation.

Hereinafter, a conventional lens movement operation device will be described with reference to the drawings. FIG. 3 is a configuration diagram of a conventional lens movement operation device, in which a gear 2 provided integrally with a sheet switch 1 rotates around a rotation shaft 3, and the rotation shaft 3 is connected to an operation board 8.
It is supported by a rotation shaft support plate 4 fixed to. The gear 2 is fixed to the upper surface of the operation board 8 and meshes with the gear 7 press-fitted into the rotating shaft of a volume 60 having the characteristics shown in FIG. The change causes the gear 7 to rotate, and at the same time, the resistance values of poly and -mu e change. The control circuit 9 controls the voltage applied to the motor 1o according to the resistance value of the volume 6, as shown in FIG. 6, and controls the rotational speed and direction of the motor 10. The rack 14 provided above the lens moving frame 13 in which the variable magnification lens 16 is installed is
It meshes with a gear 12 press-fitted into a rotating shaft 11 of a motor 10, and as the gear 12 rotates, the lens moving frame 13 moves in the forward and reverse directions of an arrow 17 using a guide ball 15 as a guide. Further, when the seesaw switch 1 is stopped being pressed and placed in the open state, an equilibrium state is maintained by the compression spring 5 fixed between the lower surface of the seesaw switch 1 and the upper surface of the operation board 8.

The operation of the conventional lens movement operation device configured as described above will be described below. By pressing the seesaw switch 1 from the arrow 18 side, the gear 2 rotates counterclockwise, and the gear 7 press-fitted into the rotating shaft of the volume 6 meshing with the gear 2 rotates clockwise. As the gear 7 rotates, the resistance value of the volume 6 increases, and when a voltage is applied to the motor 1o by the control circuit 9, the gear 12 rotates counterclockwise via the rotating shaft 11, and the rack 14 meshing with the gear 12 rotates. The lens moving frame 13 moves in the opposite direction to the arrow 17. Further, by pressing the arrow 19 side of the seesaw switch 1, the lens moving frame 13 moves with an opposite force m to that described above. Note that point A in Figures 4 and 5 is seesaw switch 1.
shows the equilibrium position of

Problems to be Solved by the Invention However, with the above configuration, there is a problem that the volume occupied by the operation section becomes large, and a variable resistor (volume) is used as a means for detecting the amount of rotation, so that poly- However, there was a problem in that the contacts deteriorated due to the sliding wear of the arms, reducing reliability.

In view of the above-mentioned problems, the present invention provides a lens movement operation device that is compact, lightweight, and highly reliable.

Means for Solving the Problems In order to solve the above problems, the lens movement operation device of the present invention includes a driving means for driving a photographing lens, a variable inductance means for changing the inductance of a coil depending on the amount of pressure, and a variable inductance. 16.1, comprising: control means for controlling the driving speed and driving direction of the driving means according to the inductance of the means;
Function The present invention allows the lens moving operation device to be made smaller and lighter due to the above-described configuration, and since there is no mechanically sliding contact portion, it is possible to significantly improve reliability.

Embodiment Hereinafter, a lens moving operation device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of the main parts of a lens moving operation device according to an embodiment of the present invention. In FIG. 1, the seesaw switch 2o is held rotatably around a rotation shaft 21, and the rotation shaft 21 is connected to a rotation shaft support plate 2 fixed to a base plate 22.
Supported by 3. Furthermore, a leaf spring 24 is provided between the seesaw switch 2o and the board 22, and the seesaw switch 2o is maintained in a balanced state by this leaf spring 24. The board 22 is a printed wiring board made of glass epoxy resin or the like, and the coil 2 is mounted on the top surface of the board 22.
6 is provided.

On the other hand, a ferrite core 26 is bonded to the lower surface of the seesaw switch 20, and the ferrite core 26 can move up and down inside the coil 25 according to the operation of the seesaw switch 2o, thereby forming a variable inductance. Further, the outer diameter of the ferrite core 26 is smaller than the inner diameter of the coil 25, so as to absorb errors during assembly of the seesaw switch 2o.

Further, a capacitor 27 is provided in parallel with the coil 26,
A control circuit 28 forming a resonant circuit and wired on the substrate 22
It is connected to the. The control circuit 28 has a built-in oscillation circuit and generates a signal with a frequency determined by the inductance of the coil 26 and the capacitor 27, and supplies a part of this signal to the viewfinder 29 for checking the shot image. are doing. The viewfinder 29 is configured to multiplex this oscillation signal onto a part of the video signal and display it. Further, the control circuit 28 generates a control voltage as shown in FIG. 2 according to the amount of depression of the scene switch 20 (oscillation frequency determined by the inductance of the coil 25) and supplies it to the motor drive circuit 30. The motor drive circuit 3o determines the rotation direction and rotation speed of the motor 31 according to the voltage, and drives the motor 31 to a rack 36 provided at the top of the lens movement frame 34 via a gear 33 press-fitted into the rotation shaft 32 of the motor 31. The rotation direction and rotation speed are transmitted. The lens moving frame 34 holds a variable magnification lens 36 and moves along an arrow 38 while being guided by a guide ball 37.
Move in the forward and reverse directions.

The operation of the lens moving operation device of this embodiment configured as described above will be explained below. First, by pressing the seesaw switch 20 at the position of the arrow 39 as shown in FIG. is inserted deeply. Therefore, the inductance of the coil 26 increases, and the oscillation frequency within the control circuit 28 decreases. The control circuit 28 applies a control voltage according to the oscillation frequency to the motor drive circuit 30, so that the gear 33 press-fitted onto the rotating shaft 32 of the motor 31 rotates clockwise. As the gear 33 rotates, the lens moving frame 34 is guided by the guide ball 37 and moves in the direction of the arrow 3.
It is possible to move in the direction of 8 and perform a magnification change operation. Therefore, depending on the amount of pressure on the seesaw switch 20, the motor 3
1 rotation speed can be changed, and the variable magnification lens 36
It becomes possible to freely control the movement speed (zoom speed). Also, by pressing the seesaw switch 2o from the arrow 40 side, in the opposite direction to the Q operation described above,
The ferrite core is pulled up from the coil 26, reducing the inductance of the coil and increasing the oscillation frequency. Therefore, the motor 31 is rotated counterclockwise by the motor drive circuit 3o, and the lens moving frame 34 is moved in the direction opposite to the arrow 38. When the seesaw switch 2o is not pressed, the seesaw switch 2o is maintained in a balanced state by the biasing force of the leaf spring 24, the output voltage of the control circuit 28 becomes zero as shown at point A in FIG. It does not rotate and the magnification change operation has stopped. Also viewfinder 2
9 has multiplexed oscillation signals, and by displaying a striped pattern of oscillation frequency corresponding to the amount of pressure on the seesaw switch 2o, the zoom speed can be indicated by the interval of the striped pattern. Further, when the zoom motor 31 is stopped, it is also possible to configure the control voltage supplied to the motor drive circuit 3o so that the oscillation signal is not displayed.

As described above, according to this embodiment, since the motor for performing zooming is configured to rotate forward and backward in accordance with the change in inductance linked to the seesaw switch, the sliding contact such as a variable resistor This enables non-contact control and improves reliability. Furthermore, by changing the oscillation frequency by changing the inductance and displaying a striped pattern according to the frequency on the viewfinder, it is possible to set the zoom speed to a desired value by checking the interval between the striped patterns. For example, if you want to zoom your zoom lens from tele to wide in 10 seconds, you can operate the seesaw switch so that the stripes are at predetermined intervals.

In the above embodiments, a leaf spring was used to keep the jee sauce inch in equilibrium, but any spring may be used as long as it has elasticity. For example, a coil spring, a sponge, etc. can be used.

Effects of the Invention As described above, the present invention provides a driving means for driving a photographing lens, a variable inductance means for changing the inductance of a coil depending on the amount of pressure, and a driving speed and a driving direction of the driving means according to the inductance of the variable inductance means. By providing a control means for controlling this, there is no mechanical sliding contact, and non-contact control is possible, resulting in a long life and significantly improved reliability. Moreover, it has the extremely excellent effect that the device can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a lens movement operating device according to an embodiment of the present invention, FIG. 2 is a diagram showing the output characteristics of the control circuit, FIG. The figure is a characteristic diagram of the rotation angle of the volume versus the resistance value, and FIG. 6 is the output characteristic diagram of the control circuit. 2o・・・Seesaw switch, 26・・・・・・
Coil, 26... Ferrite core, 28...
... control circuit, 30 ... motor drive circuit,
31... Motor, 36... Variable magnification lens. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] A photographic lens that changes the magnification of an optical image of a subject by moving in the optical axis direction, a driving means that drives the photographic lens, a variable inductance means that changes the inductance of a coil depending on the amount of pressure, and an inductance of the variable inductance means. A lens movement operation device comprising: a control means for controlling a driving speed and a driving direction of the driving means according to the driving speed and the driving direction of the driving means.