JP2001201310A - Rotation detector and lens barrel having rotation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detector reduced in size and cost, and a lens barrel having the rotation detector. SOLUTION: This rotation detector 100 is adapted to detect the amount of rotation in rotating an object, and provided with a rotor 120 holding the object and freely rotating in a first direction R1 and in a second direction R2 opposite thereto, a magnet 130 having S-poles and N-poles alternately arranged along a circle 99 round the center of rotation of the rotor 120, and a first magnetism detecting sensor 150A and a second magnetism detecting sensor 150B for detecting the magnetism of the S-pole and N-pole of the magnet 130.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device used for rotating an object such as a lens and a lens barrel having the rotation detecting device.

[0002]

2. Description of the Related Art If a video camera recorder is taken as an example of electronic equipment, a lens barrel of the video camera recorder is shown in FIG. 18, and a lens barrel 2000 has a zoom lens, an iris, a focus lens and the like. And
In addition, a manual operation type focus lens 2100 is provided as needed. This type of manual focus lens 2100 performs manual focusing by manually rotating the ring portion 2100 of the lens barrel by the user. This type of focus lens 2100
In order to detect the amount of rotation and to detect the direction of rotation, FIG.
A rotation detection device 1000 as shown in FIG. 9 is used. The rotation detecting device 1000 shown in FIG.
10, and a plurality of protrusions 1
012 are provided in a circular shape at equal intervals.

[0003] Two optical sensors 1020, 1022
Are provided facing the rotating body 1010. These sensors 1020 and 1022 have a light emitting unit 1030 and a light receiving unit 1034, respectively, as shown in FIG. When the projection 1012 of the rotating body 1010 enters between the light emitting unit 1030 and the light receiving unit 1034, the light of the light emitting unit 1030 does not reach the light receiving unit 1034. Thereby, the sensor 102
0 or the sensor 1022 can detect the passage of the protrusion 1012. FIG. 21 shows a conventional sensor 1020,
10 shows a circuit connection example 1022. These sensors 1
Reference numerals 020 and 1022 denote photointerrupters, and the light emitting unit 1030 and the light receiving unit 1034 are electrically connected to each other.

[0004]

As described above, the conventional rotation detecting device has two optical sensors 1020 and 1022.
Is required, and the plurality of protrusions 1012 are
Since it is necessary to protrude the rotation detector 010, it is not possible to reduce the size of the rotation detection device 1000, which leads to an increase in cost and a reduction in the reliability of measurement due to the large number of components. In addition, the sensor 1020,
Since the light emitting unit 1022 requires the light emitting unit 1030, there is also a problem that power consumption is large. Accordingly, it is an object of the present invention to provide a rotation detecting device capable of solving the above-described problems and achieving downsizing and cost reduction, and a lens barrel including the rotation detecting device.

[0005]

According to a first aspect of the present invention, there is provided a rotation detecting device for detecting an amount of rotation when rotating an object, the first direction and the first direction being held while holding the object. Is a rotating body rotatable in the opposite second direction, a magnet having S poles and N poles alternately arranged in the rotating body along a circle centered on the rotation center of the rotating body, and the magnet And a first magnetic detection sensor and a second magnetic detection sensor for detecting the magnetism of the S pole and the N pole.

According to the first aspect, the rotating body holds the object and is rotatable in the first direction and the second direction. The magnet is
S poles and N poles are alternately arranged along a circle centered on the rotation center of the rotator. The first magnetic detection sensor and the second magnetic detection sensor detect S and N pole magnetism of the magnet. Thus, when the object rotates together with the rotating body, the amount of rotation of the object can be detected by the magnetism detected by the first magnetic detection sensor and the second magnetic detection sensor. These first magnetic detection sensor and second magnetic detection sensor can be considerably reduced in size as compared with a conventional optical sensor having a light emitting section and a light receiving section, so that the rotation detecting device can be downsized. it can.

According to a second aspect of the present invention, in the rotation detecting device according to the first aspect, the object is a focus lens for manual operation disposed in a lens barrel.

According to a third aspect of the present invention, in the rotation detecting device according to the first aspect, the first magnetic detection sensor and the second
The magnetic detection sensor is a Hall element, and the first magnetic detection sensor and the second magnetic detection sensor are mounted on a substrate.

According to a fourth aspect of the present invention, in the rotation detecting device according to the first aspect, the first magnetic detection sensor and the second magnetic detection sensor are connected to each other.
The magnetic detection sensor is soldered to a conductor of the substrate while being inserted into a hole of the substrate.

According to a fifth aspect of the present invention, in the rotation detecting device according to the first aspect, the first magnetic detection sensor and the second magnetic detection sensor are connected to each other.
The magnetic detection sensor has a built-in Schmitt circuit. According to the fifth aspect, the Schmitt circuit receives the amplifier output of the previous stage, shapes it into “1” and “0”, and performs positive feedback from the output stage to the input, thereby shifting the operating point and storing the rectangular history. By having this, there is an advantage that the noise component is removed and the speed is increased.

According to a sixth aspect of the present invention, in the rotation detecting device according to the first aspect, the magnet is attached to the rotating body with a concave portion or a convex portion of the rotating body being a positioning portion. According to the sixth aspect, the S pole and the N pole of the magnet can be easily and accurately attached with the concave or convex portion of the rotating body as a positioning target.

A seventh aspect of the present invention is a lens barrel having a rotation detecting device for detecting an amount of rotation when rotating an object, wherein the rotation detecting device holds the object and moves in a first direction. A rotating body rotatable in a second direction opposite to the first direction, a magnet having S poles and N poles alternately arranged along a circle centered on the rotation center of the rotating body, A lens barrel having a rotation detection device, comprising: a first magnetic detection sensor and a second magnetic detection sensor that detect the magnetic properties of the S pole and the N pole of a magnet.

According to the seventh aspect, the rotating body holds the object and is rotatable in the first direction and the second direction. The magnet is
S poles and N poles are alternately arranged along a circle centered on the rotation center of the rotator. The first magnetic detection sensor and the second magnetic detection sensor detect S and N pole magnetism of the magnet. Thus, when the object rotates together with the rotating body, the amount of rotation of the object can be detected by the magnetism detected by the first magnetic detection sensor and the second magnetic detection sensor. These first magnetic detection sensor and second magnetic detection sensor can be considerably reduced in size as compared with a conventional optical sensor having a light-emitting unit and a light-receiving unit. Can be.

According to an eighth aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the object is:
This is a focus lens for manual operation.

According to a ninth aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the first magnetic detection sensor and the second magnetic detection sensor are Hall elements, and The detection sensor and the second magnetic detection sensor are mounted on a substrate.

According to a tenth aspect of the present invention, there is provided the lens barrel having the rotation detecting device according to the seventh aspect, wherein the first magnetic detection sensor and the second magnetic detection sensor are placed in holes of the substrate. It is soldered to a conductor of the substrate.

According to an eleventh aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the first magnetic detection sensor and the second magnetic detection sensor include a Schmitt circuit.

According to a twelfth aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the magnet is affixed to the rotator using a concave or convex portion of the rotator as a positioning portion. ing.

[0019]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIGS. 1 and 2 show an example of an electronic apparatus having a preferred embodiment of a lens barrel having a rotation detecting device according to the present invention. 1 and 2, the electronic device is a video camera recorder. Video camera recorder 1
0 is, for example, a digital video camera recorder,
It has a body 12, which has a housing 14 for a video cassette. A video cassette can be removably loaded into the accommodating portion 14. A lens barrel 18 is housed in the upper part 16 of the body 12. A stereo microphone 20 and a liquid crystal monitor 22 are provided on the upper part 16. This LCD monitor 2
By pointing the camera 2 in a desired direction as shown in FIGS. 1 and 2, for example, it is possible to display a color image being shot or a color image to be reproduced.
A manual focus lens 31 is arranged on the front side of the lens barrel 18, and a color view finder 32 is provided on the rear side of the lens barrel 18. In addition, a battery pack 34 is detachably attached to the side of the body 12.

FIG. 3 is a perspective view showing an example of the structure of the lens barrel 18 shown in FIGS. 1 and 2. The lens barrel 18 includes a manual focus lens 31, a rotation detecting device 100, and a first magnetic detection sensor. 150A, second magnetic detection sensor 15
0B and the like.

FIG. 4 shows an example of the internal structure of the lens barrel 18 described above. The lens barrel 18 has, for example, a rectangular parallelepiped shape or a cylindrical shape. The lens barrel 18 includes a manually operated focus lens 31, an objective lens 30, a zoom lens (magnifying lens) 40, an iris 42, a focus lens 44, and guide bars 62 and 64.
On the rear side of the lens barrel 18, a CCD (Charge Coupled Device) 5
2 is fixed. The CCD 52 includes a manually operated focus lens 31, an objective lens 30, a zoom lens 40, an iris 42, and a focus lens 4
4 is an image light receiving unit that receives an image that has passed through 4 and converts it into a photoelectric signal.

The guide bars 62 and 64 are connected to the lens barrel 18.
Is fixed parallel to the optical axis OL. A holder 70 for the zoom lens 40 is arranged on these guide bars 62.
Along 4, it can be moved and positioned between predetermined strokes. The iris 42 is for reducing the amount of light incident from the objective lens 30 and includes a driving unit 76.
, The amount of aperture of light can be changed. The iris 42 is located at the center 18 </ b> A of the lens barrel 18.
It is provided around the optical axis OL.

The focus lens 44 includes the objective lens 3
0, a lens for focusing light from a subject that has passed through the zoom lens 40 and the iris 42.
The focus lens 44 moves along the guide bars 62 and 64 by the operation of the drive unit 199. The image received by the CCD 52 can be sent to the computer 400 or displayed on the color viewfinder 32 after predetermined processing is performed by the image processing unit 130. The user checks the image by looking at the color view finder 32.

The manually operated focus lens 31 shown in FIG. 3 is rotated by the user about the optical axis OL by hand, and has a rotation detecting device 100.
The rotation detecting device 100 has a structure as shown in FIG. 5, and a manually operated focus lens 31 is held by a ring 110. A circular hole 124 is formed in the center between the ring 110 and the rotating part 120A. The hole 124 is formed around the optical axis OL.
The rotating part 120A and the ring 110 are discs, and are made of a non-magnetic material such as plastic, aluminum, or ceramics.

As shown in FIGS. 5 and 6, the rotating body 120 has a rotating part 120A and a ring 110.
Reference numeral 10 is integral with the rotating unit 120A. A magnet 130 is provided on the inner surface side of the ring 110. This magnet 130 has an N pole and an S pole alternately,
Are arranged in a multi-pole magnetized type. As shown in FIG. 6, the N pole and the S pole of the magnet 130 are alternately arranged at an angle of α °, and a neutral zone NZ is provided between the S pole and the N pole. As shown in FIG. 5, magnets 130 are embedded and arranged in the recesses 126 of the ring 110, respectively. Each magnet 130 has a ring 1
That is, they are arranged at equal intervals along the ten circles 99. The circle 99 is a circle centered on the optical axis OL, and the optical axis OL is at the center of the hole 124.

The first magnetic detection sensor 150A shown in FIG.
The magnetic detection sensor 150B is positioned so as to be slightly away from the rotating body 120. In the example of FIG. 3, the substrate 150C holds the first magnetic detection sensor 150A and the second magnetic detection sensor 150B. This substrate 150C is attached to the lens barrel 18, for example. As the first magnetic detection sensor 150, for example, a Hall element can be used. The magnetism detection sensor 150 is a sensor that detects the magnetism of the magnet 130 when the N pole and the S pole of the magnet 130 pass sequentially as the rotating body 120 rotates in the direction of R1 or R2. . The rotating body 120 in FIG. 5 is rotatable along the first direction R1 or the second direction R2 in the lens barrel 18 in FIG. 3 by the user rotating the ring 110 by hand.

The first detection output S1 of the first magnetic detection sensor 150A and the second magnetic detection sensor 1 as shown in FIGS.
The second detection output S2 of 50B is sent to the signal processing unit 300 shown in FIGS. The signal processing unit 300 receives the first detection output S1 and the second detection output S2 of FIG. 7 or FIG. 8 to determine whether the rotating body 120 shown in FIG. 4 is rotating in the first direction R1 or the second direction R2. Is determined, and the number of N and S poles of the magnet 130 passing through the magnetic detection sensor 150 is counted, whereby the first direction R1 or the second direction R2 of the rotating body 120 is determined.
The rotation position, that is, the rotation amount is detected. Further, the rotation speed can be obtained from the number of pulses per unit time as needed. Information on the rotation direction of the rotating body 120 and the position (the amount of rotation) of the rotating body 120 is supplied to the computer 400 as information. The number of N poles and S poles of the magnet 130 required for the rotating body 120 may be provided by the number of waves required according to the performance. In this case, the formation angle α ° of the N pole and the S pole of each magnet 130
Is the same.

First and second magnetic detection sensors 150A, 150
The Hall element used as 0B is a magnetoelectric conversion element,
It converts the magnetic quantities of the N pole and S pole of the magnet 130 into electric quantity (Hall output).
System and InSb system. As the magnet 130, for example, a magnet in which a magnetic substance is included in rubber and magnetized, or a magnet in which a magnetic substance is included in plastic and magnetized,
Or something like a sintered magnet can be adopted. Further, a liquid magnet may be used as the magnet. This liquid magnet is injected into the concave portion 126 as shown in FIG. After being injected, the liquid magnet is solidified by cooling, and then, for example, is alternately magnetized with N poles and S poles on the sensor surface side. Liquid magnets are, for example, rare earth magnets.The characteristics of this liquid magnet are that it is easy to magnetize, easy to thin, and has the advantage of strong mechanical strength when used together with a metal ring. is there.

FIG. 10 shows the first magnetic detection sensor 15 of FIG.
0A first detection output S1 and second magnetic detection sensor 150B
2 shows the second detection output S2. The first and second detection outputs S1 and S2 are shifted by 1/4 wavelength. FIG. 8 shows FIG.
5 shows a circuit example of the first magnetic detection sensor 150A and the second magnetic detection sensor 150B shown in FIG. These first magnetic detection sensor 150A and second magnetic detection sensor 150B are mounted on substrate 150C. First magnetic detection sensor 15
0A and the second magnetic detection sensor 150B are electrically connected, and their respective sensor units 400, amplifying units 410,
It has a Schmitt circuit section 420. Sensor unit 400
Is a Hall element as described above. When the sensor section 400 detects the magnetism of the N pole and the S pole of the magnet, it converts the magnetism into a magneto-electric signal and sends it to the input side of the amplification section 410. The amplifier 410 amplifies the electric signal and supplies the electric signal to the Schmitt circuit 420.

The structures of the first magnetic detection sensor 150A and the second magnetic detection sensor 150B are the same, and include a reference voltage Vcc, voltage output units Vout1 and Vout2,
And it is connected to the ground GND. A transistor 430 is connected to the output side of the Schmitt circuit section 420, and the Schmitt circuit section 420 operates according to the operation diagram shown in FIG. 9 to supply an ON signal to the base of the transistor 430. As a result, the first detection output S1 and the second detection output S2 can be output. FIG. 9 shows operating points when NS double magnetization is detected. (1) High output is output by an O magnetic field. (2) When the magnetic field increases to the Bop level on the S pole side,
Output. (3) Even if it becomes weak to Bop, the output remains unchanged at Low. (4) After the magnetic field has increased to the Brp level on the N pole side, the output returns to High. The area between Bop and Brp is called Bh hysteresis (history).

FIG. 11 shows a ring 110 and a ring 110.
FIG. 3 is a cross-sectional view illustrating a structural example of a magnet 130 provided in the first embodiment. A ring-shaped magnet 130 is fixed to the surface 110A of the ring 110 by embedding. A first magnetic detection sensor 150A and a second magnetic detection sensor 150B are arranged to face the ring-shaped magnet 130. The gap e between the first magnetic detection sensor 150A, the second magnetic detection sensor 150B, and the magnet 130 is, for example, 0.5 mm, but may be smaller as long as mechanical accuracy can be maintained. Conversely, if the output is sufficiently high, it may be wider.

FIG. 12 shows a portion A of FIG. 11 in an enlarged manner. The first magnetic detection sensor 150A and the second magnetic detection sensor 150B can employ, for example, Hall ICs. The sensor 150A and the second magnetic detection sensor 150B are connected to the substrate 150C via the terminal 700.
Is electrically connected to the conductor portion 150D by using a soldering portion 150E. In this case, in order to reduce the size, a part of the first magnetic detection sensor 150A and a part of the second magnetic detection sensor 150B are held in the hole 730 of the substrate 150C so as to enter. Also magnet 130
Is positioned by being embedded in the recess 126 of the surface 110 </ b> A of the ring 110, so that the magnet 130 can be fixed at an accurate position with respect to the ring 110. In this case, the magnet 130
The ring 110 is formed using, for example, a double-sided tape 139.
Is attached to the bottom of the concave portion 126. However, instead of using the double-sided tape 139 in this way, the ring 130 is sandwiched using a material such as an iron plate.
Of course, it may be fixed to the ten concave portions 126.

FIG. 13 shows the first magnetic detection sensor 150A and the second magnetic detection sensor 15 mounted on the substrate 150C.
0B is shown. These first magnetic detection sensors 150
A and the second magnetic detection sensor 150B are, for example, nα ° +
At an angle of α ° / 2, they are arranged offset from the optical axis OL. In this case, n is an integer of 0 or more, and the first
Magnetic detection sensor 150A and second magnetic detection sensor 150B
Are the first and second detection outputs S1 and S2 as shown in FIG.
Is arranged at an angle of nα ° + α ° / 2 with respect to the angle α ° at which the S pole and the N pole are formed in FIG.

Next, an example of use of a lens barrel provided with the above-described rotation detecting device will be described. Figure 1 and Figure 2
And the manual ring 110 shown in FIGS. 3 and 4 and the ring 110 and the rotating body 120 are appropriately rotated in the R1 direction or R2 direction shown in FIG. . Thus, manual focus adjustment in the lens barrel 18 is performed.
When the ring 110 and the rotating body 120 are turned, the manual focus lens 31 performs focus adjustment by moving back and forth along the optical axis OL. At this time, the first magnetic detection sensor 150A and the second magnetic detection sensor 150B shown in FIG.
Outputs the first detection output S1 or the second detection output S2 to the signal processing unit 300. For example, in FIG. 10, the first detection output S1 and the second detection output S2 are counted by the signal processing unit 300 of FIG.
The amount of rotation of the rotating body 120 in the R1 direction or the R2 direction can be detected according to the number of S poles and N poles of the magnet 130 shown in FIG.

Next, another embodiment of the present invention will be described with reference to FIGS. 14, the magnet 130 is fixed to the ring 110 by, for example, a double-sided tape 800. A recess 110X is formed in the ring 110, and a ring-shaped magnet 130 is fixed to the recess 110X. In another embodiment of the present invention in FIG.
A concave portion 110Y is formed in 10. This recess 110
The magnet 130 is fixed to Y using, for example, a double-sided tape 800. As is apparent from a comparison between FIG. 14 and FIG. 15, in FIG.
0X is open to the outer peripheral side, but in FIG.
10X is not open to the outer peripheral side. Therefore, the inner peripheral surface of the magnet 130 is positioned on the inner peripheral surface 120X of the ring 110. In FIG. 15, the magnet 1
The outer peripheral surface of the ring 30 is positioned by the inner peripheral surface 110Z of the ring 110.

In the embodiment shown in FIG. 16, the magnet 130 is fixed in the recess 140X of the ring 110. However, a part of the magnet 130 is
Embedded in X. As a fixing method in this case,
As in the case of FIG. 14 or FIG. 15, a double-sided tape or another type can be adopted. In the embodiment of the invention shown in FIG. 17, the magnet 130 is embedded and fixed in the recess 150X of the ring 110. On the other hand, the first magnetic detection sensor 150A and the second magnetic detection sensor 15
OB is embedded in the hole 150F of the substrate 150C.

In the embodiment of the present invention, the use of the two magnetic detection sensors of the present invention makes it possible to reduce the thickness in the direction of the optical axis OL in FIG. 5 as compared with the conventional optical sensor. And the size of the manual focus ring mechanism can be further reduced. When a N-pole and a S-pole are multi-polarized by providing a concave portion in the rotating body or ring, the magnet is fixed by double-sided tape or a simple adhesive or by press-fitting or mechanical fixing by caulking or the like. Can be realized. In this case, the magnet may be a magnet made of a rubber containing a magnetic substance, magnetized, a magnet made of a plastic containing a magnetic substance, or a sintered magnet. As shown in FIG. 5, the S pole and the N pole are magnetized at any angle of α °.

The first magnetic detection sensor 150A shown in FIG.
Substrate 150C fixing magnetic detection sensor 150B
May be an ordinary printed wiring board or a flexible printed wiring board. First
As described above, the magnetic detection sensor and the second magnetic detection sensor are provided with two holes in the substrate 150C, and are fixed by embedding or fitting into each hole. Thus, the size of the rotation detection device in the optical axis direction can be further reduced.

Further, the rotation detecting device 100 has a first magnetic detection sensor 150A and a second magnetic detection sensor 150B, and the progress or delay of the first detection output S1 and the second detection output S2 shown in FIG. By checking the condition, the rotation direction of the rotating body 120 shown in FIG. 5 in the first direction R1 or the second direction R2 can also be detected. When the rotation direction is R1, the phase relationship is between the first detection output S1 and the second detection output S2. When the rotation direction is R2, the phase relationship is between the first detection output S1 and the output S3. When the rotation direction is R1, the second detection output S2
Latches the state "1" of the first detection output S1 at the falling edge of the signal and outputs the direction signal 1. When the rotation direction is R2, the output S
At the fall of 3, the state "0" of the first detection output S1 can be latched to output the direction signal 0. This latch is to transfer and hold D data to Q using a Dtype flip-flop or the like.

The present invention is not limited to the above embodiment. In the present embodiment, the rotation detection device 100 can detect the rotation direction and the rotation angle of the manually operated focus lens described above. However, the rotation detection device 100 is not limited to this, and the rotation detection target is not limited to the manually operated focus lens, and may be another object. The object may be, for example, detection of a position of a pointing device such as a mouse, detection of a rotation amount of a rotor of a spindle motor, or the like. Further, the lens barrel is not limited to the one mounted on the video camera recorder, but can be applied to other electronic equipment, for example, a digital still camera, a notebook computer, a telephone, a game machine, or other equipment equipped with a lens. Further, the present invention can be applied to an input device such as a jog dial which needs to detect a rotation direction.

[0042]

As described above, according to the present invention,
The rotation detection device and the lens barrel can be reduced in size, thickness, and cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an electronic apparatus including a lens barrel having a rotation detection device according to the present invention.

FIG. 2 is an exemplary perspective view of the electronic apparatus shown in FIG. 1 as viewed from the rear side;

FIG. 3 is a perspective view showing an example of a lens barrel.

FIG. 4 is a diagram showing an example of a sectional structure of a lens barrel.

FIG. 5 is a perspective view showing an example of a rotation detection device for a lens barrel.

FIG. 6 is a diagram showing an example of forming a magnet in FIG. 5;

FIG. 7 is a diagram illustrating an example of a first magnetic detection sensor, a second magnetic detection sensor, a signal processing unit, and a computer.

FIG. 8 is a diagram showing a circuit example of a first magnetic detection sensor and a second magnetic detection sensor.

FIG. 9 is a diagram illustrating a characteristic example of a Schmitt circuit unit included in the first magnetic detection sensor and the second magnetic detection sensor.

FIG. 10 is a diagram showing an example of output signals of a first magnetic detection sensor and a second magnetic detection sensor.

FIG. 11 is a diagram showing a ring, a magnet, a first magnetic detection sensor, and a second magnetic detection sensor.

FIG. 12 is an enlarged view showing a portion A in FIG. 11;

FIG. 13 is a view showing a mounting example of a first magnetic detection sensor and a second magnetic detection sensor.

FIG. 14 is a diagram showing another embodiment of the present invention.

FIG. 15 is a diagram showing still another embodiment of the present invention.

FIG. 16 is a diagram showing still another embodiment of the present invention.

FIG. 17 is a view showing still another embodiment of the present invention.

FIG. 18 is a diagram showing an example of a conventional lens barrel.

FIG. 19 is a diagram showing a rotation detection device in a conventional lens barrel.

FIG. 20 is a diagram showing a light emitting unit and a light receiving unit of a conventional rotation detecting device.

FIG. 21 is a diagram showing a circuit example of a photo interrupter of a conventional rotation detecting device.

[Explanation of symbols]

18 ... lens barrel, 99 ... circle, 100
..Rotation detectors, 120 ... rotors, 130 ...
Magnet, 150A: first magnetic detection sensor, 15
0B: second magnetic detection sensor, 420: Schmitt circuit section, R1: first direction, R2: second direction,
OL: Center of rotation (optical axis)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shigeki Motoyama 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2F063 AA35 BA30 BC02 CA15 CA34 DA01 DB07 DD03 GA52 GA61 GA68 GA72 KA02 LA02 LA11 LA30 ZA01 2H044 DA01 DB01 DE06

Claims (12)

[Claims] 1. A rotation detection device for detecting an amount of rotation when rotating an object, the rotation detecting device holding the object and rotating freely in a first direction and a second direction opposite to the first direction. A magnet having S poles and N poles alternately arranged in the rotator along a circle centered on the rotation center of the rotator; and magnetizing the S pole and the N pole of the magnet. A rotation detection device comprising: a first magnetic detection sensor and a second magnetic detection sensor for detecting. 2. The rotation detecting device according to claim 1, wherein the object is a focus lens for manual operation arranged in a lens barrel. 3. The magnetic sensor according to claim 1, wherein the first magnetic detection sensor and the second magnetic detection sensor are Hall elements, and the first magnetic detection sensor and the second magnetic detection sensor are mounted on a substrate. The rotation detecting device as described in the above. 4. The rotation detection device according to claim 1, wherein the first magnetic detection sensor and the second magnetic detection sensor are soldered to conductors of the substrate while being inserted into holes of the substrate. apparatus. 5. The first magnetic detection sensor and the second magnetic detection sensor have a built-in Schmitt circuit.
3. The rotation detecting device according to 1. 6. The rotation detecting device according to claim 1, wherein the magnet is attached to the rotating body with a concave portion or a convex portion of the rotating body being a positioning portion. 7. A lens barrel having a rotation detecting device for detecting a rotation amount when rotating an object, wherein the rotation detecting device holds the object, and controls a first direction and a first direction. Is a rotating body rotatable in the opposite second direction; a magnet having S poles and N poles alternately arranged along a circle centered on the rotation center of the rotating body; and the S pole of the magnet. And a first magnetic detection sensor and a second magnetic detection sensor for detecting the magnetism of the N pole. 8. The lens barrel according to claim 7, wherein the object is a focus lens for manual operation. 9. The method according to claim 7, wherein the first magnetic detection sensor and the second magnetic detection sensor are Hall elements, and the first magnetic detection sensor and the second magnetic detection sensor are mounted on a substrate. A lens barrel having the rotation detection device according to claim 1. 10. The rotation detecting device according to claim 7, wherein the first magnetic detection sensor and the second magnetic detection sensor are soldered to conductors of the substrate while being inserted into holes of the substrate. Lens barrel with device. 11. The lens barrel according to claim 7, wherein the first magnetic detection sensor and the second magnetic detection sensor include a Schmitt circuit. 12. The lens barrel having the rotation detecting device according to claim 7, wherein the magnet is attached to the rotating body with a concave portion or a convex portion of the rotating body being a positioning portion.