JP2909323B2 - Beam deflecting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam deflecting device used for image blur correction and the like.

[0002]

2. Description of the Related Art In recent years, automation of photographing apparatuses such as still cameras and video cameras has been advanced, and apparatuses equipped with automatic exposure and automatic focusing mechanisms have been widely put into practical use. Some techniques for realizing a shake correction function for correcting image shake have also been put to practical use.

FIG. 3 is a diagram showing a schematic configuration of a conventional optical apparatus for performing shake correction.

In FIG. 3, reference numerals 2 a and 2 b denote two opposing transparent plates, and a space sealed by the transparent plates and a film 3 sealing the outer periphery is filled with a liquid having a high refractive index (not shown). These form a variable apex angle prism.

[0005] Reference numerals 4a and 4b denote frames for holding the variable apex angle prism, and each of the transparent plates 2a and 2b forming a part of the variable apex angle prism is rotatably held around a pitch axis 5a and a yaw axis 5b. doing. Reference numeral 6a denotes a flat coil fixed to one end of the front frame 4a, and a permanent magnet 7a and yoke 8a, 9a are arranged on opposite sides of the flat coil to constitute a closed magnetic circuit. Reference numeral 11a denotes an arm integrally formed with the frame 4a.
have. 12a and 13a are the slits 10a
Interposed therebetween a light receiving element, for example PSD such that output varies according to the position of the spot of the light emitting element and received light beams of IRED such example is disposed opposite, light-emitting element
The light beam emitted from the element 12a is transmitted to the light receiving element 13a after passing through the slit 10a.

[0006] 14a, 14b is the pitch direction of the entire device,
This is a shake detector attached to a support portion of the device so as to detect a shake amount in the yaw direction. Reference numeral 15 denotes a control circuit such as a microcomputer that controls the entire apparatus, 16 denotes a coil drive circuit that drives the flat coil 6a in accordance with a drive signal from the control circuit 15, and 17 denotes an operating point of the flat coil 6a. It is a point that cannot be represented in space.

Although not shown in FIG. 3, the flat coil 6b, the permanent magnet 7b, the yoke 8
b, 9b, slit 10b, arm 11b, light emitting element 12
b, the light receiving element 13b is arranged, and functions similarly to the operation on the pitch side.

[0008]

In the above conventional example, the driving torque for driving the variable apex angle prism in, for example, the pitch direction is determined by the distance (distance) between the action point 17 and the pitch axis 5a and the flat coil 6a. , Permanent magnet 7a, yoke 8
a, 9a, and is determined by the product of the driving force generated by the magnetic circuit formed by 9a. Therefore, in order to increase the driving torque, it is conceivable to increase the distance between the action point 17 and the pitch shaft 5a or to increase the driving force of the magnetic circuit having the above-described configuration.

However, in the former case, the size of the magnetic circuit portion is increased and the cost is increased. In the latter, the current input to the flat coil 6a must be increased, and the power consumption of the magnetic circuit increases.

[0010] It is an object of the present invention (the purpose of the invention), driven hand
An object of the present invention is to provide a light beam deflecting device capable of increasing a driving torque for tilting an optical member without increasing the size of the step , increasing the cost, and increasing power consumption.

[0011]

Means for Solving the Problems In order to achieve the above object, the present invention provides a variable apex angle prism that tilts an optical member to deflect a light beam, and is provided integrally with the optical member,
Holding means for holding the optical member; magnetic circuit forming means;
And a coil fixed to the holding means,
A magnetic circuit formed by circuit forming means and the coil;
The optical member is tilted by the driving force generated by the interaction of
Light deflecting device having driving means for moving the light beam.
The coil in a direction along the plane of the optical member,
Before the optical member tilts farthest from the tilt center axis when tilting
At a position on the holding means so as to be fixed to the holding means.
This is a light beam deflecting device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a diagram showing a mechanism and a circuit configuration of a main part of an optical apparatus according to an embodiment of the present invention. In FIG. 1, reference numerals 102a and 102b denote two opposing transparent plates. A space sealed by the film 103 sealing the outer periphery is filled with a liquid having a high refractive index (not shown), and these form a variable apex angle prism.

Reference numeral 104 denotes a front frame which holds the variable apex angle prism, and holds the transparent plates 102a and 102b forming a part of the variable apex angle prism so as to be rotatable around a yaw axis 105. Reference numeral 106 denotes a flat coil fixed to one end of the front frame 104. A permanent magnet (not shown) and yokes 108 and 109 are arranged opposite to both surfaces thereof, and a member 110 for arranging them is opposed to each other. Are arranged at right angles to these, and the flat coil 106
A closed magnetic circuit is constituted by 0. 111
Holds the flat coil 106, and furthermore, the front side frame 104
Arm for transmitting power to the arm.

Reference numeral 112 denotes a coil drive circuit for driving the magnetic circuit, and reference numeral 113 denotes a control circuit such as a microcomputer for controlling the apparatus.

Next, the operation of the present apparatus having the above configuration will be described.

The coil drive amount is determined by the coil drive circuit 112 according to the drive signal from the control circuit 113. The driving amount is input to the magnetic circuit having the above-described configuration, and the driving force generated here is transmitted to the front frame 104 via the arm 111, and the variable tip held by the front frame 104 is controlled. The angular prism rotates around the yaw axis 105. As a result, the light incident from the front of the front frame 104 passes through the variable apex prism to change its optical axis, and as a result, shake correction is performed.

Here, in the present embodiment, the magnetic circuit is arranged such that its movement direction does not substantially intersect with the axial direction of the yaw axis 105.

FIG. 2 is a diagram for explaining that a higher torque can be obtained with this arrangement than with the conventional arrangement.
3 are denoted by the same reference numerals.

In FIG. 2, reference numeral 114 denotes a flat coil 10
6, which is a point that is not represented in space as in the conventional example.

Here, the driving torque is represented by the following equation.

Drive torque = ri × Fi
∴i = 1,2, ri is pitch axis 5a or yaw axis 1
Distance Fi from 05 to the point of action of the flat coils 6a, 106, Fi is the driving force of the flat coils 6a, 106.

From the above equation, assuming that the driving forces Fi of the flat coils 6a and 106 in the system of the present embodiment and the conventional system are the same, the magnitude of the driving torque for driving the variable apex angle prism is as follows. Obviously depends on the distance ri.

Therefore, in the present embodiment, the arrangement of the magnetic circuit does not cross the axial direction of the yaw axis 105.
The distance r ₁ in FIG. 2 can be made larger than r ₂ , and the driving torque can be increased.

Further, since it is not necessary to enlarge the magnetic circuit, the cost of the apparatus does not increase.

Further, since the driving torque can be increased, the electric power required to obtain the conventional driving torque is reduced. This makes it possible to reduce the size of the battery serving as a power supply required for the present apparatus.

FIG. 2 shows only the yaw direction,
The pitch direction has the same configuration.

[0028]

[0029]

(Correspondence between the Invention and the Embodiment) In the above embodiment, the transparent plate 102a is used as the optical member of the present invention, the transparent plates 102a and 102b and the film 103 are used as the variable apex prisms, the front frame 104 and the arms. 111 is the holding means,
The permanent magnet, yoke 108, 109 and member 110
A flat coil 106 is attached to the coil, a yaw axis
105 corresponds to the tilt center axis .

As described above, according to the present invention, the driving torque for tilting the optical member can be increased without increasing the size of the driving means , increasing the cost, and further increasing the power consumption. It is possible to provide a light beam deflecting device that can perform the operation.

Therefore, the size and cost of the driving means are increased,
Further, it is possible to increase the driving torque for driving the light deflecting unit without increasing power consumption.

[Brief description of the drawings]

FIG. 1 is a mechanism diagram showing a main configuration of an optical apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a driving torque of a variable apex angle prism in a system of the present embodiment and a conventional system.

FIG. 3 is a mechanism diagram of a conventional optical device having a light deflecting function.

[Explanation of symbols]

102a, 102b Transparent plate 103 Film 104 Front frame 105 Yaw axis 106 Flat coil 108, 109 Yoke 110 Member

Continuation of the front page (72) Inventor Naoya Kaneda 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-4-20947 (JP, A) JP-A-62-153816 ( JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 5/00

Claims (1)

(57) [Claims] A variable angle prism for tilting an optical member to deflect a light beam; holding means provided integrally with the optical member for holding the optical member; magnetic circuit forming means;
The magnetic circuit comprises a coil fixed to the holding means.
Between the magnetic circuit formed by the path forming means and the coil
The optical member is tilted by the driving force generated by the interaction
Driving means for causing the light beam to deflect.
The coil is in a direction along the plane of the optical member,
The most distant from the center axis of tilt when the optical member tilts
At a position on the holding means, fix it to the holding means.
A light beam deflecting device characterized in that: