JPH08146480A - Position sensor for optical axis correcting lens - Google Patents

Abstract

PURPOSE: To precisely detect the position of an optical axis correcting lens, in an optical system apparatus requiring a so-called hand shake correction in an applied state, such as a handy video camera apparatus and a telescope. CONSTITUTION: Light projected from a light emitting part 8 is formed like a beltshape longer than length in the lateral direction of a light receiving element 9, the light emitting part 8 is attached to the side of the movable lens 2 or fixed lens 3 of the optical axis correcting lens 1, so as to orthogonally cross the longitudinal directions of the light from the light emitting part 8 and of the image forming element 9, when viewing in the optical axial direction and the light receiving element 9 is attached to the side of the fixed lens 3 or movable lens 2 of the optical axis correcting lens 1, so as to make the longitudinal direction of the element 9 coincident with a radial direction centering on an optical axis. Moreover, the light emitting part 8 and the light receiving element 9 are attached to be relative each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical axis correcting lens position sensor. Specifically, for example, in a hand-held type video camera device, or an optical system device such as a telescope that requires so-called image stabilization in a used state, a novel optical device capable of accurately detecting the position of the optical axis correction lens. It is intended to provide a position sensor for an axis correcting lens.

[0002]

2. Description of the Related Art For example, in a handy type video camera device, as a method for correcting the camera shake, an afocal lens composed of a convex lens and a concave lens is arranged in front of a taking lens system as an optical axis correcting lens, and these convex lenses are used. And / or a method of correcting a camera shake by moving a concave lens in a direction orthogonal to the optical axis is known.

In such a system, the position of the optical axis correcting lens must be detected, and as a means therefor, the position of the optical axis correcting lens is orthogonal to two directions, for example, HV.
Direction (H direction is horizontal and V direction is vertical)
It is conceivable that the position of the optical axis correcting lens in each direction is detected by two position sensors.

FIGS. 5 to 7 are diagrams for explaining a method of correcting a camera shake by moving an afocal lens composed of a convex lens and a concave lens as an optical axis correcting lens and moving these lenses in a direction orthogonal to the optical axis. It is a figure.

Since the position sensors of the two optical axis correcting lenses have the same structure,
Only the position sensor of the optical axis correcting lens (which extends in the HH direction in FIG. 5) for detecting the directional position will be described.
Regarding the position sensor of the optical axis correcting lens (which extends in the VV direction in FIG. 5) for detecting the position in the V direction,
The description will be omitted by giving the same reference numerals to the similar portions of the position sensor of the optical axis correcting lens that detects the position in the H direction.

The position sensor a of the optical axis correcting lens is an LED
And a light receiving element c made of PSD.

Reference numeral d denotes an optical axis correcting lens arranged in front of a main lens system (not shown), which has a movable lens e and a fixed lens f.

Reference numeral g denotes a light distribution of the light emitted from the light emitting portion b, the diameter of the light distribution g is made larger than the size of the light receiving element c in the lateral direction, and the light emitting portion b is moved to the movable lens e side, and The light receiving elements c are arranged on the fixed lens f side, respectively.

Reference numerals h and h denote suspensions that support a movable lens e of an optical axis correcting lens d so that the movable lens e can move while maintaining a state of being parallel to a fixed lens f, and i and i denote the movable lens e at a predetermined position. And x is an optical axis of a main lens system (not shown).

The distribution of the light quantity of the light distribution g of the light emitting portion b becomes smaller from the center toward the periphery as shown by the contour lines in FIG. 6 (a), and the position sensor a of the optical axis correcting lens has the above distribution. The position is detected depending on the position of the light receiving element c where the center of the light g (the position where the light is strongest) has moved.

[0011]

However, in the position sensor a of the above optical axis correcting lens, the light distribution g of the light emitting portion b is used.
Is not a correct light distribution j (hereinafter referred to as a normal light distribution) that can be expressed by a regular contour line as shown in FIG. 6A, but an irregular contour line as shown in FIG. 6B. There was a case where an erroneous light distribution k (hereinafter, referred to as an erroneous light distribution) that does not appear.

In FIG. 7, the LED irradiating the false light distribution k is a light emitting portion b of the position sensor a of the optical axis correcting lens for detecting the H direction.
The relationship between the false light distribution k and the light receiving element c in the case of being used in FIG.

FIG. 7 (a) shows a case where the false light distribution k and the center of the light receiving element c coincide with each other, and FIG. 7 (b) shows a state in which the false light distribution k is moved downward (the light emitting portion is v (When moving only in the direction).

In the case of FIG. 7B, it should be judged that there was no movement in the H direction, but when the false light distribution k moves downward, it is received by the light receiving element c. Since the contour line of the false light distribution k is similar to the distribution of the light amount when the normal light distribution j shown in FIG. 6A is moved to the position shown by the chain double-dashed line in FIG. 7B, the light receiving element c is It is determined that the light emitting unit b has moved by the distance l, which causes the erroneous detection of the position sensor a of the optical axis correcting lens. In addition, the position of the strongest light from the light emitting portion b deviating from the line V-V also caused a false detection.

In order to solve the above problem, a method of enlarging the size of the light receiving element c so that the entire moving range of the light distribution g can be included. However, enlarging the light receiving element c increases the size of the structure. In addition, there is a problem that the cost is increased (the larger the light receiving element, the higher the unit price).

A method of narrowing the light distribution g with respect to the light receiving element c so that the entire moving range of the light distribution g falls within the light receiving element c is also conceivable, but in order to narrow down the light distribution g. In this case, a special lens must be used, and there is a problem that the structure is complicated and the cost is increased.

[0017]

In order to solve the above-mentioned problems, a position sensor for an optical axis correcting lens according to the present invention forms light emitted from a light emitting portion into a strip shape longer than the length of a light receiving element in the lateral direction. Then, the light emitting unit is arranged on the movable lens side or the fixed lens side of the optical axis correcting lens so that the longitudinal direction of the light from the light emitting unit and the longitudinal direction of the light receiving element are orthogonal to each other when viewed in the optical axis direction. The light-receiving portion is attached so as to face the longitudinal direction of the light-receiving portion and the radiation direction around the optical axis so as to face the fixed lens side or the movable lens side of the optical axis correcting lens.

[0018]

Therefore, according to the position sensor of the optical axis correcting lens of the present invention, the size and cost of the structure can be increased by enlarging the light receiving element, and the structure for reducing the light distribution can be complicated and the cost can be increased. It is possible to improve the accuracy of detecting the position of the optical axis correcting lens without causing a disadvantage.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the position sensor of the optical axis correcting lens of the present invention will be described below with reference to the embodiments shown in the accompanying drawings.

In the illustrated embodiment, the position of the optical axis correcting lens is divided into two components which are orthogonal to each other, for example, HV direction (H direction is horizontal direction and V direction is vertical direction).
The position of the optical axis correcting lens in each direction is detected by two position sensors, and the two optical axis correcting lens position sensors have the same configuration. Therefore, only the position sensor of the optical axis correcting lens for detecting the position in the H direction (which extends in the H-H direction in FIG. 2) will be described in detail, and the position sensor of the optical axis correcting lens for detecting the V direction ( 2) (extending in the VV direction in FIG. 2), the description thereof will be omitted by assigning the same reference numerals to the respective portions in the respective portions of the position sensor of the optical axis correcting lens that detects the position in the H direction. To do.

Reference numeral 1 denotes an optical axis correcting lens, which has a movable lens 2 and a fixed lens 3.

Reference numeral 4 denotes a main lens system having a plurality of lenses (not shown), which is behind the optical axis correcting lens 1 (the direction diagonally downward to the left in FIG. 2 is the front, and the direction diagonally upward to the right is the rear, The direction that goes diagonally upward to the left is the right, and the direction that goes diagonally downward to the right is the left. When the direction is expressed in the following description, it is based on this direction. The fixed lens 3 is located on the front side of the lens system 4.

Reference numerals 5 and 5 denote suspensions that support the movable lens 2 of the optical axis correcting lens 1 so that the movable lens 2 can move while maintaining a state in which the movable lens 2 is parallel to the fixed lens 3. Reference numerals 6 and 6 denote predetermined suspensions for the movable lens 2. It is a moving coil type drive means for moving to a position.

Reference numerals 7 and 7 are position sensors of the optical axis correcting lens, and have light emitting portions 8 and 8 made of LEDs and light receiving elements 9 and 9 made of PSD.

Reference numeral 10 denotes a movable lens holder having a substantially ring shape, and an opening 11 for holding the movable lens 2 is formed in the center thereof.
Further, mounting pieces 12, 12 for mounting the light emitting portions 8, 8 of the position sensors 7, 7 of the optical axis correcting lens are integrally projecting outward at the upper end portion and the left end portion thereof. The coil bobbin 13 at the lower end and the right end.
13 is integrally provided so as to project outward.

Numeral 14 is a substantially ring-shaped fixed lens holder, and an opening 15 for holding the fixed lens 3 is formed in the center thereof.
Further, mounting pieces 16, 16 for mounting the light receiving elements 9, 9 of the position sensors 7, 7 of the optical axis correcting lens are integrally projecting outward at the upper end portion and the left end portion thereof. It is set up.

The suspensions 5 and 5 are vertical springs 17,
, And horizontal springs 18, 18, ..., which are formed by punching and bending a sheet metal material of a predetermined size, and are movable with the lens barrel. The movable lens holder 10 is supported in front of the main lens system 4 so as to be vertically and horizontally movable by being bridged between the lens holder 10 and the lens holder 10.

The drive means 6, 6 are coils 19, 19 wound around the coil bobbins 13, 13 of the movable lens holder 10.
And an E-shaped yoke 20 fixed to the main body side (not shown),
20 and the magnet 2 attached to the yoke 20, 20
The movable lens holder 10 is moved in the vertical direction and the horizontal direction with respect to the main lens system 4 by supplying power to the coils 19 and 19.

Reference numerals 22 and 22 denote processed light distributions obtained by partially shielding the light emitted from the light emitting portions 8 by a light shielding plate having a slit. The processed light distributions 22 and 22 are light receiving elements 9 and
It has a strip shape extending in the direction orthogonal to the longitudinal direction of 9,
The light emitting parts 8 and 8 are mounting pieces 12 and 1 of the movable lens holder 10.
2 and the light-receiving elements 9 and 9 are fixed lens holders 14
Are attached to the attachment pieces 16 and 16, respectively.

X is the optical axis of the main lens system 4.

Correct light distribution 2 emitted from the light emitting section 8
3 (hereinafter referred to as “normal light distribution”), the amount of light decreases from the center to the periphery as shown by the contour lines in FIG. 3A, and the position sensor 7 of the optical axis correction lens uses the normal light distribution 23. The position is detected depending on the position of the light receiving element 9 at which the center (position of the strongest light) has moved.

However, the light emitted from the light emitting section 8 may become an irregular light distribution 24 (hereinafter referred to as an erroneous light distribution) as shown by contour lines in FIG.
If the light radiated from the light source was irregular like the false light distribution 24, it was a cause of erroneous detection (see conventional problems).

However, in the above-mentioned processed light distribution 22, the left and right are largely shielded to form a band-like shape as shown by a chain double-dashed line in FIG. 3B, so that FIG. 4A and FIG. )
The processed light distribution 22 obtained by processing the false light distribution 24 as shown in FIG.
However, even if it moves only in the V direction, it does not detect that there is a movement in the H direction. Further, even if it is detected that there is a movement in the H direction, the maximum deviation width does not exceed the width 25 of the processed light distribution 22, so that it is better than the conventional position detection means using the false light distribution 24 as it is. The accuracy can be improved.

In order to improve the accuracy of position detection as in the conventional case, the structure is not enlarged, the structure is complicated, and the cost is not increased.

Needless to say, the narrower the width 25 of the processed light distribution 22, the higher the position detection accuracy.

In the above embodiment, the light emitting portion 8 of the position sensor 7 of the optical axis correcting lens is fixed to the movable lens 2 side, and the light receiving element 9 is fixed to the fixed lens 3 side. The same effect can be obtained by fixing the light emitting section 8 to the fixed lens 3 side and the light receiving element 9 to the movable lens 2 side.

[0037]

As is apparent from the above description, the position sensor of the optical axis correcting lens of the present invention is arranged in front of the main lens system and can be decentered in a substantially plane orthogonal to the optical axis. A position sensor for an optical axis correcting lens having a light emitting portion and a light receiving element long in one direction for receiving light emitted from the light emitting portion, for detecting the position of the supported optical axis correcting lens. The light emitted from the light emitting portion is formed into a strip shape longer than the length in the lateral direction of the light receiving element, and the longitudinal direction of the light from the light emitting portion and the longitudinal direction of the light receiving element are orthogonal to each other when viewed in the optical axis direction. The fixed lens of the optical axis correction lens is such that the light emitting portion is on the movable lens side of the optical axis correction lens so that the light emitting portion is oriented in the same direction, and the longitudinal direction of the light receiving portion is aligned with the emission direction centered on the optical axis. It is characterized by being attached to each side.

Further, another position sensor of the optical axis correcting lens of the present invention is arranged in front of the main lens system and is supported so as to be eccentric in a substantially plane orthogonal to the optical axis. A position sensor of an optical axis correcting lens having a light emitting portion and a light receiving element long in one direction for receiving light emitted from the light emitting portion for detecting the position of Light is formed in a strip shape longer than the length of the light receiving element in the lateral direction, and the light emitting section is arranged so that the longitudinal direction of the light from the light emitting section and the longitudinal direction of the light receiving element are orthogonal to each other when viewed in the optical axis direction. On the fixed lens side of the optical axis correction lens,
It is characterized in that the light receiving portion is attached to the movable lens side of the optical axis correcting lens so that the longitudinal direction thereof coincides with the radiation direction centered on the optical axis.

Therefore, according to the position sensor of the optical axis correcting lens of the present invention, the size of the structure is increased by increasing the size of the light receiving element and the cost is increased, and the structure for reducing the light distribution is complicated and the cost is increased. It is possible to improve the accuracy of detecting the position of the optical axis correcting lens without causing a disadvantage.

It should be noted that the specific shapes and structures shown in the above-mentioned embodiments are merely examples of the embodiment in implementing the position sensor of the optical axis correcting lens of the present invention, and the specific shapes and structures are The technical scope of the invention should not be limitedly interpreted.

[Brief description of drawings]

FIG. 1 shows an embodiment of a position sensor for an optical axis correcting lens of the present invention, together with FIGS. 2 to 4, and is a plan view schematically showing the whole.

FIG. 2 is an exploded perspective view.

FIG. 3 is a conceptual diagram showing (a) and (b) an example of light distribution as a basis of a light emitting unit.

FIG. 4 is a diagram showing a relationship between a light distribution after processing and a light receiving element, (a) showing a state where the light distribution has not moved, and (b) a conceptual diagram showing a state where the light distribution has moved. is there.

FIG. 5 shows an example of a conventional position sensor of an optical axis correcting lens together with FIGS. 6 and 7, and this figure is an exploded perspective view.

FIG. 6 is a conceptual diagram showing (a) and (b) an example of light distribution as a basis of a light emitting unit.

FIG. 7 is a diagram showing a relationship between a light distribution and a light receiving element (a).
FIG. 3B is a conceptual diagram showing a state in which the light distribution has not moved, and FIG.

[Explanation of symbols]

 1 Optical Axis Correction Lens 2 Movable Lens 3 Fixed Lens 4 Main Lens System 7 Optical Axis Correction Lens Position Sensor 8 Light Emitting Section 9 Light Receiving Element 22 Processing Light Distribution (Light)

Claims (2)

[Claims] 1. A light emitting section and a light emitting section for detecting the position of an optical axis correcting lens which is disposed in front of a main lens system and is eccentrically supported in a substantially plane orthogonal to the optical axis. A position sensor of an optical axis correcting lens having a light receiving element that is long in one direction to receive light emitted from the light emitting element, wherein the light emitted from the light emitting unit is longer than the length in the lateral direction of the light receiving element. It is formed in a band shape, and the light emitting unit is arranged on the movable lens side of the optical axis correcting lens so that the longitudinal direction of the light from the light emitting unit and the longitudinal direction of the light receiving element are orthogonal to each other when viewed in the optical axis direction. A position sensor for an optical axis correcting lens, characterized in that the light receiving section is attached to each of the fixed lens side of the optical axis correcting lens so that the longitudinal direction thereof coincides with the emission direction centered on the optical axis. 2. A light emitting section and a light emitting section for detecting the position of an optical axis correcting lens which is disposed in front of the main lens system and is supported eccentrically in a substantially plane orthogonal to the optical axis. A position sensor of an optical axis correcting lens having a light receiving element that is long in one direction to receive light emitted from the light emitting element, wherein the light emitted from the light emitting unit is longer than the length in the lateral direction of the light receiving element. It is formed in a band shape, and the light emitting portion is arranged on the fixed lens side of the optical axis correcting lens so that the longitudinal direction of the light from the light emitting portion and the longitudinal direction of the light receiving element are orthogonal to each other when viewed in the optical axis direction. A position sensor for an optical axis correcting lens, characterized in that the light receiving section is attached to each of the movable lens side of the optical axis correcting lens so that a longitudinal direction thereof coincides with a radiation direction centered on the optical axis.