JPH06294609A - Position detector for movable body - Google Patents

Abstract

PURPOSE:To provide a position detector for detecting the shift of a movable body from a reference position in which inexpensive compositional members are employed while decreasing the number thereof. CONSTITUTION:Two sets of light emitting elements 1a, 1b and light receiving elements 2a, 2b for detecting the rotary angle theta are disposed, as a rotational position detecting section for a lens-barrel 10, on a camera body along a horizontal line circumscribing the opposing outer periphery of a rear lens-barrel 10b under a state where the lens-barrel 10 is located at a referential rotational position thereof. Furthermore, two sets of light emitting elements 1c, 1d and light receiving elements 2c, 2d for detecting the rotary angle thetax are disposed on the camera body along a normal circumscribing the opposing outer periphery of a front lens-barrel 10c located at a referential rotary position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable body position detecting device,
More specifically, the present invention relates to a movable body position detection device that detects a deviation of a movable body supported inclinable from a reference position.

[0002]

2. Description of the Related Art Conventionally, in a lens frame supporting mechanism that enables the lens barrel unit to rotate in the optical axis direction for camera shake correction and automatic tracking control, the rotation of a movable lens frame. Proposals have been made regarding position detection devices that detect angles. As one of them, an angle detection device and an image blur prevention device disclosed in Japanese Patent Laid-Open No. 4-32714 relate to an image blur prevention device for a lens barrel, and a lens barrel rotation is performed to prevent camera shake. This is a proposal for a rotational position detection device that detects a moving angle.

FIG. 13 is a perspective view showing the external appearance of the above-mentioned conventional rotary position detecting device when it is applied to a movable lens barrel unit having a spherical support. As shown in the figure, the movable lens barrel unit has a lens optical axis O of the lens barrel.
Spherical portion 110a having its center of rotation G as the center of rotation
The lens barrel 110 has a lens barrel 110 disposed in the center. The lens barrel 110 is attached to the camera body via the spherical portion 110a.
It is rotatably supported around the axis and around the Y axis. However, the rotation around the optical axis O which is the rolling operation is
Be in a regulated state.

The taking lens 1 is provided on the front side of the lens barrel 110.
11 is mounted, and CCD1 which is an image pickup device is provided at the rear end.
12 is installed. The spherical members 110a are provided with driving members 123 and 133 which are rotated in a predetermined direction so as to be displaced in the respective directions so as to be in pressure contact with each other. The drive members 123 and 133 are driven by the drive motor 12
4,134 are rotatably driven via a gear train including gearboxes 121,131 and drive shafts 122,132. Further, angular velocity detectors 147 and 146 for detecting camera shake are attached to the camera body that supports the lens barrel 110.

A slit plate 141 having an arcuate slit 141a is fixed to the outer shape of the lens barrel 110. The center of the arc of the slit 141a is deviated from the center G of the spherical portion by a predetermined amount. Further, a light emitting element 144 and a PSD (semiconductor position detecting element) 143 are provided at a position facing the center of the slit 141a.
Is supported by the camera body. The light emitting element 144 and the PSD 143 are the lens barrel 11 for the camera body.
0 for detecting the relative rotation angle θy about the Y axis, and a PSD for detecting the relative rotation angle θx about the X axis of the lens barrel 110 and the slit plate, which are not shown in FIG. It shall be similarly arranged.

FIG. 14 is a block diagram of a control circuit of the conventional image blur prevention device for a lens barrel unit. When the camera shake prevention control is performed by the control circuit, first, the camera shake of the camera body is detected by the angular velocity detectors 146 and 147.
And the blur information is captured by the MPU (microprocessor unit) 163, which is an arithmetic unit having a memory, via the A / D converter 162. On the other hand, the output of the PSD 143 or the like is transmitted via the A / D converter 161 to M
Taken into the PU 163, the rotation angle θ around the Y axis of the lens barrel 110
Calculate y to obtain. The rotation angle θx of the lens barrel 110 around the X axis is also obtained by taking in the output of another PSD (not shown).

Based on the drive correction information stored in the MPU 163, the MPU 163 receives camera shake information and a rotation angle θ.
A combined drive signal corresponding to y and θx is calculated. The digital signal of the combined drive signal is converted into an analog signal by the D / A conversion circuit 164 and output to the motors 124 and 134. Then, the lens barrel 110 is rotationally driven by the motors 124 and 134, and proper camera shake correction is performed.

The PSD 143 is arranged in the longitudinal direction along the X-axis as shown in the operation state diagram around the slit plate in FIG. Then, when the lens barrel 110 is in the neutral position of rotation, it outputs an output value indicating the light beam centroid position of the light beam region 141a 'at the reference position incident through the slit 141a. When the slit plate 141 is rotated by the relative rotation angle θy from the reference position, the slit position is also moved to the position of the slit 141b. Then, the irradiation area of the incident light flux on the PSD 143 changes to the irradiation area 141b '.
Then, from the PSD 143, a signal giving the position of the center of gravity of the irradiation area 141b 'is output as information on the rotation angle θy. FIG. 16 shows the PSD 1 accompanying the rotation of the slit plate 141.
It is a figure which showed the change of the irradiation area of the incident light beam on 43. As shown in the figure, the lens barrel 110 rotates from the reference position, which is the neutral position of rotation, to the left and right by the angle θy0, which is the Y-axis rotation limit,
The incident light beam area on the PSD 143 when the slit 141a is moved to the positions 141c and 141d is the irradiation area 141c 'or the irradiation area 141d in the vertical direction by the dimension S from the reference light beam area 141a' in the Y-axis direction. Move to ′. An output signal based on the amount of movement of the irradiation area is output. The dimension R in FIG. 16 indicates the distance from the center G at the reference position of rotation of the lens barrel 110 to the center of gravity of the incident light beam irradiation area 141a '.

FIG. 17 is a view showing an operating state around a slit plate of another conventional rotary position detecting device. In this conventional example, the detection slits are arranged in the direction toward the center of rotation, and the PSD 153 is arranged along the direction orthogonal to the Y axis. When rotated by the relative rotation angle θy0 about the Y-axis, the irradiation area of the incident light flux moves from the irradiation area 151a ′ to the irradiation area 151c ′ or the irradiation area 151d ′.

[0010]

However, in the above-described conventional rotational position detecting device for a lens barrel, it is first necessary to use an expensive PSD which is an element for detecting the position of the center of gravity of an incident light beam as a detecting element. There was a cost disadvantage. Further, since the slit provided between the light emitting portion and the light receiving portion of the conventional rotary position detecting device described above has an arc shape, an error in the shape directly appears as an error in the output of the light receiving portion. Therefore, there is also a problem that the slit manufacturing is restricted due to accuracy problems.

The present invention has been made in order to solve the above-mentioned inconvenience, and in a device for detecting a deviation from a reference position of a movable body supported so as to be tiltable in one direction and another direction, a position of the movable body is detected. The number of components for detection is small,
Another object is to provide a movable body position detecting device in which the member is inexpensive.

[0012]

A movable body position detecting device of the present invention detects a deviation from a reference position of a movable body which is supported so as to be tiltable in one direction and a direction intersecting with the movable body position detecting apparatus. And a light-emitting element provided at a predetermined first position, and at least 4 necessary for receiving light from the light-emitting element and detecting a deviation of the movable body from the reference position.
A light receiving element provided at a predetermined second position to obtain three independent information, and a calculation means for calculating a deviation of the movable body from the reference position based on light from the light receiving element. To do.

[0013]

When the movable body moves from the reference position, the amount of movement from the reference position is calculated based on the outputs of the four independent light receiving elements provided at the predetermined second position.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part of a lens barrel of a camera-integrated video tape recorder having a movable body position detecting device according to a first embodiment of the present invention. The camera of the present embodiment detects the camera shake, and based on the camera shake information,
The lens barrel described above is rotationally driven to enable shake correction.

Like the lens barrel 110 of the conventional camera described in FIG. 13, the lens barrel of the present camera and its drive mechanism are rotated about the X axis in the vertical direction and about the Y axis in the horizontal direction. Is configured to be rotatable. Therefore, of the constituent members in FIG. 1, the same constituent members are designated by the same reference numerals.

The lens barrel 10 of this embodiment has a rotation center G
The driving members 123 and 13 supported by the camera body by the spherical surface portion 10a centered on the
By the rotation of 3, rotation is driven in the rotation angle θx and θy directions. CC, which is an image sensor, is provided at the rear of the lens barrel 10.
D112 is installed. Further, angular velocity detectors 147 and 146 for camera shake detection are mounted on the camera body.

In the camera of this embodiment, the rotational position of the lens barrel 10, which is a movable body, is detected by the detection section which constitutes the movable body position detection apparatus. The detection section has a cylindrical shape. The rear lens barrel portion 10b and the front lens barrel portion 10c are fixedly mounted on the camera main body, and are composed of four sets of light emitting / receiving elements capable of obtaining independent outputs. That is, the lens barrel 1
In the state where 0 is at the reference position of the rotation, the rotation angle θy detection unit is located at the first position and the second position on the camera body along the horizontal line that contacts the outer periphery of the rear barrel portion 10b. Of two sets of light emitting elements 1a and 1b and a light receiving element 2
a and 2b are provided. Further, a rotation angle θx detection unit is formed at a first position and a second position on the camera body along a vertical line that is in contact with the outer circumference of the front lens barrel unit 10c at the rotation reference position. Two sets of light emitting elements 1c and 1d and light receiving elements 2c and 2d are arranged.

In FIG. 2, the light receiving elements 2a, 2b,
It is a diagram which shows the output current characteristic with respect to the incident light quantity of 2c and 2d. The output current changes substantially linearly with the amount of incident light.

FIG. 3 is a block diagram of a detection unit circuit of the position detecting apparatus. Light receiving surface "A" for detecting the rotation angle θy,
The light receiving elements 2a and 2b indicated by "B", and the light receiving elements 2c and 2c indicated by "C" and "D" for detecting the rotation angle θx.
The output signal of 2d is input to S / H circuits 23, 24, 25, and 26 that perform sample hold processing, respectively. Further, the signals are converted into digital signals by the A / D conversion circuits 27, 28, 29, 30 and taken in by the CPU 31 which is a calculation means. The rotation angle θy indicating the deviation from the reference position,
The value of θx is A / D conversion circuits 27 and 28, or 29.
Based on the difference value between the output values of
Is calculated in. When performing camera shake correction, the output signals of the angular velocity detectors 147 and 146 for camera shake detection,
The rotation angle θy of the lens barrel detected by the detection unit,
Based on θx, the drive motors 124 and 134 are driven to perform the blur correction.

FIG. 4 shows a rotation angle θy detecting section in a state where the lens barrel 10 is at the reference position for rotation,
FIG. 7 is a vertical cross-sectional view of the outer periphery of the rear lens barrel portion 10b around the light emitting / receiving element portion as viewed from the front of the lens barrel. As shown in the figure, of the luminous fluxes emitted from the light emitting elements 1a and 1b, half of the luminous flux is blocked by the outer circumference of the lens barrel, and the other half luminous flux enters the light receiving elements 2a and 2b. In this state, the light receiving element 2
The output values of a and 2b are equal, and the rotation angle θy is set to 0. The rotation angle θx of the lens barrel 10 in the reference state
Similar output signals can be obtained from the light emitting elements 1c and 1d and the light receiving elements 2c and 2d of the detector.

FIG. 5 shows a state in which the lens barrel 10 is rotated around the Y axis from the state of FIG. 4 and the center position of the rear lens barrel portion 10b is displaced from the center O1 to the center O2, for example. FIG. 6 is a vertical cross-sectional view of the rear lens barrel portion 10b around the light emitting / light receiving element portion as viewed from the front of the lens barrel. In this state, one of the light quantities incident on the light receiving elements 2a and 2b decreases and the other increases. The rotation angle θy is obtained from the output difference.

In FIG. 6, the lens barrel 10 rotates about the X-axis, and the center position of the front lens barrel portion 10c is, for example, the center O1.
FIG. 7 is a vertical cross-sectional view of the front lens barrel portion 10c around the light-emitting / light-receiving element portion in a state of being displaced from the center O2 to the center O2 as seen from the front of the lens barrel. In this state, one of the light amounts incident on the light receiving elements 2c and 2d increases and the other decreases. The rotation angle θx is obtained from the output difference.

As described above, in the rotation angle detecting device for the lens barrel of the present embodiment, it is not necessary to use PSD, which is an expensive light receiving element used in the conventional detecting device, as a light receiving element, which is relatively inexpensive. Since a light receiving element that is an element and can obtain an output signal proportional to the amount of light is used, the detection apparatus becomes a low-cost apparatus. Furthermore, since it is not necessary to use a slit plate with high manufacturing accuracy, in terms of cost and
It is possible to provide a detection device which is advantageous in terms of space.

In the camera of this embodiment, the light emitting / receiving elements for detecting the rotation angles θx and θy are arranged on the camera body around the front and rear portions of the lens barrel. Both the light emitting / receiving elements for detecting the angles θx and θy may be collectively arranged around the front portion or the rear portion of the lens barrel. Further, in the above embodiment, two sets of light emitting / receiving elements for detecting the rotation angle θx or θy are provided, but if there is no problem in accuracy, one set is provided for each. You may make it comprised by each light emitting / light receiving element.

FIG. 7 is a sectional view of a lens barrel of a camera-integrated video tape recorder incorporating a movable body position detecting device according to the second embodiment of the present invention. As with the camera of the first embodiment, the camera of the present embodiment also detects camera shake of the camera body, and based on the camera shake information, rotationally drives the lens barrel to enable camera shake correction. It is a thing.

Like the lens barrel 110 of the conventional camera described in FIG. 13, the lens barrel 40 of the present camera and its drive mechanism are also rotatable about the center G about the X axis in the vertical direction. It is possible to rotate about the Y axis in the vertical direction in the drawing of FIG. Therefore, detailed description of the drive mechanism is omitted.

In the camera of this embodiment, the rotational position of the lens barrel 40, which is a movable body, is detected by the detection unit that constitutes the movable body position detection device. The detection unit is the lens barrel 4.
0, one light emitting element 42 attached to the rear surface side of the CCD 41 arranged at the rear portion of the CCD 41, and the lens barrel 4
It is fixed to the second position of the camera body 45 behind 0, and
And a light receiving element 44 capable of obtaining two independent outputs.

FIG. 8 is a circuit block diagram of the detecting section of the movable body position detecting device of this camera. The light-receiving element 44 applied to the present detection circuit unit has a light-receiving surface “A” divided into four,
Light receiving elements 44a, 44 having "B", "C", "D"
b, 44c, 44d. Further, the light emitting element 42 emits a circular light beam, and the center of the irradiation area Lg of the emitted light is in the state where the lens barrel 40 is at the reference position for rotation, and the light receiving element 44 has a center. The center positions of the light receiving surfaces "A", "B", "C", and "D" are matched. However, even if the position does not match the center position, it is possible to set the origin position by electrically adjusting (A + B) = (C + D) (A + C) = (B + D).
When the lens barrel 40 rotates from the reference position,
As will be described later, the light receiving surfaces “A”, “B”, “C”,
The balance of the amount of light input to “D” is lost, and the rotation angle is obtained. The light receiving elements 44a, 44b, 44c, 4
The output characteristic of 4d is similar to the characteristic shown in FIG.

Light receiving element 44 constituting the above light receiving element 44
The output signals of a, 44b, 44c, and 44d are received by the light receiving element 4
The outputs of 4a and 44b are sent to the adder circuit 51 and the light receiving element 44.
Outputs of c and 44d are sent to the adder circuit 52, and light receiving elements 44b and
The output of 44d is added to the addition circuit 53, and the light receiving element 44
The outputs of a and 44c are input to the adder circuit 54, respectively. Therefore, the output of the adder circuit 51 is the light receiving element 44.
Output current values of the upper light receiving surfaces "A" and "B", and the output of the adder circuit 52 gives output current values of the lower light receiving surfaces "C" and "D". Further, the output of the adder circuit 53 gives the output current values of the right light receiving surfaces "B" and "D", and the output of the adder circuit 54 is the left light receiving surfaces "A" and "C". Give the output current value.

The outputs of the adder circuits 51, 52, 53 and 54 are S / H circuits 55 and 5 for performing sample hold processing.
6, 57, 58. Furthermore, the A / D conversion circuit 5
Converted to digital signal by 9, 60, 61, 62,
It is taken in by the CPU 63 which is a calculation means. Then, in the CPU 63, as described later, the light receiving element 44
Based on the sample and hold output signals of a, 44b, 44c, and 44d, the values of the rotation angles θy and θx about the Y axis or the X axis from the reference position are calculated.

In the position detecting device, when the camera shake correction is performed based on the detection signal, the angular velocity detectors 147, 14 for detecting the camera shake are the same as in the camera of the first embodiment.
6 and the rotation angles θy and θx of the lens barrel detected by the detection unit, the drive motors 124 and 1
34 is driven and the camera shake correction is performed.

FIG. 9 is a side view around the detector when the lens barrel 40 is rotated clockwise (in the direction of the arrow in the figure) by an angle θy about the Y axis. FIG. 10 is a view taken along the line AA of FIG. 9, showing the irradiation state of the light receiving element 44. When the lens barrel 40 is at the reference position,
As shown in FIG. 8, the center of the irradiation area Lg of the emitted light of the light emitting element 42 coincides with the center of the light receiving surface of the light receiving element 44. However, as shown in FIG. 9, the lens barrel 40 is
When rotated clockwise (in the direction of the arrow in the figure) about the axis, the center of the irradiation area Lh of the light emitting element 42 is shifted downward from the center of the light receiving surface of the light receiving element 44, as shown in FIG. . Therefore, the output values of the light receiving elements 44a and 44b decrease, and the output values of the light receiving elements 44c and 44d increase. Due to the output difference, a clockwise rotation angle θ around the Y axis
y is calculated.

FIG. 11 is a side view around the detecting portion when the lens barrel 40 is rotated counterclockwise (in the direction of the arrow in the drawing) about the Y axis by an angle θy. FIG. 12 is a view taken along the line AA of FIG. 11, showing the irradiation state of the light emitting element 42 with the light emitted from the light emitting element 42. FIG. 11 above
As shown in FIG. 12, when the lens barrel 40 rotates counterclockwise (in the direction of the arrow in the drawing) about the Y axis, as shown in FIG.
The center of the irradiation area Li of the light emitting element 42 is shifted upward from the center of the light receiving surface of the light receiving element 44. Therefore, the output values of the light receiving elements 44a and 44b increase and the output values of the light receiving elements 44c and 44d decrease. A counterclockwise rotation angle θy about the Y axis is calculated from the output difference.

Even when the lens barrel 40 is rotated about the X axis or about the Y and X axes, the light emitting element 42 emits light according to the rotation direction. The center position moves, and the light receiving elements 44a, 44b,
The output values of 44c and 44d increase and decrease respectively. As described above, when the lens barrel 40 rotates about the X and Y axes,
The output values of the light receiving elements 44a, 44b, 44c, and 44d increase and decrease, respectively, and the CPU 6 is based on the amount of change.
Based on 3, rotation angles θy and θx about the X and Y axes are calculated.

As described above, in the position detecting device for the lens barrel of the present embodiment, a large space is not required for disposing the light emitting element and the light receiving element. Therefore, the space saving around the lens barrel is reduced. Realization of the camera, which facilitates miniaturization of the camera. Further, similarly to the first embodiment, since the light receiving element which is an inexpensive element and which can obtain the output signal proportional to the light quantity is used, in the second embodiment, the deviation information is detected by one set of the light emitting element and the light receiving element. Since it is possible, it becomes a low-cost device as a detection device. Further, since it is not necessary to use a slit plate, it is possible to provide a position detecting device which is advantageous in terms of cost and space.

In the above embodiment, the light emitting element 4
2 is arranged on the lens barrel side, and the light receiving element 44 is arranged on the camera body side. As a modification thereof, the light receiving element 44 is arranged on the lens barrel side and the light emitting element 42 is arranged on the camera body side. It may be provided.

[0037]

As described above, the movable body position detecting device of the present invention is a device for detecting a deviation from a reference position of a movable body supported so as to be tiltable in one direction and another direction. By using a light receiving element that outputs an output current corresponding to an inexpensive incident light amount as an element for position detection that does not need to be used, the number of constituent members for position detection is reduced, and a movable body that is cost effective A position detection device can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part around a lens barrel of a camera-integrated video tape recorder having a movable body position detection device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an output current characteristic with respect to an incident light amount of a light receiving element applied to the position detecting device of the camera of FIG.

FIG. 3 is a block diagram of a detection unit circuit of the position detection device for the camera shown in FIG.

FIG. 4 is a vertical cross-sectional view of the rotation angle θy detection unit of the position detection device of FIG. 1 around the light emitting / receiving element unit of the rear lens barrel when the lens barrel is at the reference position.

5 is a rotation angle θy of the position detecting device for the camera shown in FIG. 1;
FIG. 6 is a vertical cross-sectional view of a light-emitting / light-receiving element portion of the rear lens barrel portion when the lens barrel is rotated, which is a detection portion.

6 is a rotation angle θx of the position detecting device for the camera shown in FIG. 1;
FIG. 6 is a vertical cross-sectional view of a light-emitting / light-receiving element portion of the front lens barrel portion when the lens barrel rotates, which is the detection portion.

FIG. 7 is a cross-sectional view of essential parts of a lens barrel of a camera-integrated video tape recorder having a movable body position detection device according to a second embodiment of the present invention.

8 is a circuit block diagram of a detection unit of the movable body position detection device of the camera of FIG.

9 is a side view around the detection unit when the lens barrel of the camera of FIG. 7 is rotated clockwise by an angle θy in the Y-axis direction.

FIG. 10 is a view on arrow AA in FIG. 9.

11 is a side view around the detection unit when the lens barrel of the camera shown in FIG. 7 is rotated counterclockwise in the Y-axis by an angle θy.

FIG. 12 is a view on arrow AA of FIG. 11.

FIG. 13 is a perspective view of a main part around a lens barrel of a camera-integrated video tape recorder incorporating a movable body position detection device showing a conventional example.

FIG. 14 is a block diagram of a control circuit of the conventional movable body position detecting device of FIG.

FIG. 15 is an operation state diagram of a detection unit in the conventional movable body position detection device of FIG.

FIG. 16 is a diagram showing a state in which the position detecting element in the conventional movable body position detecting device of FIG. 13 is irradiated with emitted light.

FIG. 17 is a view showing a state in which the position detecting element in another conventional movable body position detecting device is irradiated with emitted light.

[Explanation of symbols]

Reference numeral 1a, 1b, 1c, 1d, 42 ... Light-emitting element 2a, 2b, 2c, 2d ..... Light-receiving element 10, 40 ........... Lens barrel (movable body) 31, 63 …………………… CPU (calculation means) 42 ……………… Light-emitting elements 44,44a, 44b, 44c, 44d ………………
Light receiving element θx, θy ……………… Rotation angle (deviation from the reference position)

Claims (1)

[Claims] 1. A device for detecting a deviation from a reference position of a movable body supported so as to be tiltable in one direction and a direction intersecting with the one direction, the device being provided at a predetermined first position. Light emitting element and a light receiving element provided at a predetermined second position for receiving at least four independent information necessary for detecting the deviation of the movable body from the reference position by receiving light from the light emitting element. A movable body position detecting device comprising: a moving body position detecting device for calculating a deviation of the movable body from a reference position based on light from a light receiving element.