JP2001255171A - Rotation detector and lens barrel with rotation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detector which can be made compact and low- cost, and a lens barrel having a rotation detector. SOLUTION: This rotation detector 100 for detecting the quantity of the rotation, when an object is rotated includes a rotor 120 which is freely rotatable in a first direction R1 and a second direction R2 opposite to the first direction R1 while holding the object, a magnet 130 which has sets of S poles and N poles arranged to the rotor 120 along a circle 99, centerered about a rotation center OL of the rotor 120 and dividing parts for not generating magnetism between the set of the S pole and N pole and the adjacent set of the S pole and the N pole, and one magnetic sensor 150 for sensing the magnetism of the S pole and the 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 When taking a video camera recorder as an example of an electronic apparatus, a lens barrel of the video camera recorder is shown in FIG. 23. 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.
4, a rotation detecting device 1000 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. Each of these sensors 1020 and 1022 has a light emitting unit 1030 and a light receiving unit 1034 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. 26 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 rotation of an object, wherein the second direction is opposite to the first direction while holding the object. A rotating body rotatable in a direction, and a set of S poles and N poles arranged in the rotating body along a circle about the center of rotation of the rotating body, wherein the set of S poles and N poles is provided. And a magnet having a divided portion that does not generate magnetism between the pair of the S pole and the N pole adjacent to the magnet, and one magnetic detection sensor that detects the magnetism of the S pole and the N pole of the magnet. It is a rotation detecting device characterized by the above-mentioned.

According to the first aspect, the rotator is rotatable in a first direction and a second direction opposite to the first direction while holding the object. The magnet has an S pole and an N pole arranged on the rotating body along a circle centered on the rotation center of the rotating body.
It has a set of poles. Between the pair of S poles and N poles and the pair of adjacent S poles and N poles, there is a divided portion that does not generate magnetism. One magnetic detection sensor detects the magnetism of the S pole and the N pole of the magnet. Thereby, since the magnet has a divided portion that does not generate magnetism between the pair of the S pole and the N pole and the adjacent pair of the S pole and the N pole, one magnetism detection sensor is It is possible to distort a part of the output waveform that is detected and outputted from the pole magnetism. Accordingly, it is possible to determine whether the rotating body is rotating in the first direction or the second direction and to detect the amount of rotation of the rotating body by using only one magnetic detection sensor. By having such a dividing portion, a magnetic idle transport (idle running) section occurs, and a waveform peak does not occur in that section (a waveform peak occurs only at the center of each pole). ). Further, since the output waveform in the idle transport (idle running) section is integrated, it has a certain slope, and is close to a waveform connecting the peaks of both sides of the idle transport (idle running) section.
As a result, the waveform is deformed from the sine wave and rotates forward,
When the waveform is reversed by the reverse rotation, the rotation direction and the speed can be detected by one magnetic detection sensor.
Since only one magnetic detection sensor needs to be used as described above, the size of the rotation detection device can be reduced.

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 magnetic detection sensor is a Hall element, and the amplifier for amplifying an output waveform of the Hall element is:
It is arranged at the same position as the Hall element or at another position. According to the third aspect, it is possible to select whether to set the Hall element and the amplifier at the same position or at different positions.

According to a fourth aspect of the present invention, in the rotation detecting device according to the first aspect, the divided portion of the magnet is a notch. According to the fourth aspect, it is possible to easily form the magnetic neutral zone by simply providing the notch in the magnet.

According to a fifth aspect of the present invention, in the rotation detecting device according to the first aspect, the divided portion of the magnet is a nonmagnetic portion. According to the fifth aspect, the divided portion of the magnet can be set only by providing the nonmagnetic portion.

According to a sixth aspect of the present invention, in the rotation detecting device according to the third aspect, the output waveform of the Hall element has a saw-tooth shape, and the time of the rising portion and the time of the falling portion of the output waveform are compared. Then, the rotation direction of the rotating body is detected. According to the sixth aspect, the rotation direction of the rotating body can be easily detected by comparing the time of the rising part and the time of the falling part of the output waveform of the Hall element.

A seventh aspect of the present invention is a lens barrel having a rotation detecting device for detecting the rotation of an object, wherein the rotation detecting device holds the object and controls a first direction and a first direction. Has a rotating body rotatable in the opposite second direction, and a set of S poles and N poles arranged in the rotating body along a circle centered on the rotation center of the rotating body.
A magnet having a division that does not generate magnetism between a pair of a pole and an N pole and an adjacent pair of the S pole and the N pole, and one magnet for detecting the magnetism of the S pole and the N pole of the magnet A lens barrel having a rotation detection device, comprising: a detection sensor.

According to the present invention, the rotating body holds the object and is rotatable in a first direction and a second direction opposite to the first direction. The magnet has an S pole and an N pole arranged on the rotating body along a circle centered on the rotation center of the rotating body.
It has a set of poles. Between the pair of S poles and N poles and the pair of adjacent S poles and N poles, there is a divided portion that does not generate magnetism. One magnetic detection sensor detects the magnetism of the S pole and the N pole of the magnet. Thereby, since the magnet has a divided portion that does not generate magnetism between the pair of the S pole and the N pole and the adjacent pair of the S pole and the N pole, one magnetism detection sensor is It is possible to distort a part of the output waveform that is detected and outputted from the pole magnetism. Accordingly, it is possible to determine whether the rotating body is rotating in the first direction or the second direction and to detect the amount of rotation of the rotating body by using only one magnetic detection sensor. By having such a dividing portion, a magnetic idle transport (idle running) section occurs, and a waveform peak does not occur in that section (a waveform peak occurs only at the center of each pole). ). Further, since the output waveform in the idle transport (idle running) section is integrated, it has a certain slope, and is close to a waveform connecting the peaks of both sides of the idle transport (idle running) section.
As a result, the waveform is deformed from the sine wave and rotates forward,
When the waveform is reversed by the reverse rotation, the rotation direction and the speed can be detected by one magnetic detection sensor.
Since only one magnetic detection sensor needs to be used as described above, the size of the rotation detection device can be reduced.

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:
It is a focus lens for manual operation arranged in the lens barrel.

According to a ninth aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the magnetic detection sensor is a Hall element, and the amplifier for amplifying an output waveform of the Hall element is the Hall element. It is arranged at the same position as the element or at another position. According to the ninth aspect, it is possible to select whether to set the Hall element and the amplifier at the same position or at different positions.

According to a tenth aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the divided portion of the magnet is a notch. According to the tenth aspect, it is possible to easily form the divided portion which is a magnetic neutral zone only by providing the cutout portion in the magnet.

According to an eleventh aspect of the present invention, in the lens barrel having the rotation detecting device according to the seventh aspect, the divided portion of the magnet is a non-magnetic portion. According to the eleventh aspect, the divided portion of the magnet can be set only by providing the nonmagnetic portion.

According to a twelfth aspect of the present invention, in the lens barrel having the rotation detecting device according to the ninth aspect, the output waveform of the Hall element has a saw-tooth shape, and the time of the rising portion and the time of the falling portion of the output waveform are different. The rotation direction of the rotating body is detected by comparing the times. According to the twelfth aspect, the rotation direction of the rotating body can be easily detected by comparing the time of the rising part and the time of the falling part of the output waveform of the Hall element.

[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 detection device 100, and one magnetic detection sensor. 150 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 north pole and the south pole of the magnet 130 are alternately arranged at an angle of α °. As an example, four sets of N and S poles G of the magnet 130 are arranged along the circle 99. In the set G of the S pole and the N pole, a magnetic dividing part 990 is provided between them. The dividing portion 990 is a portion that does not generate magnetism, which can be called a dead body.
For example, aluminum, non-magnetic stainless steel (SU
S), brass, magnesium and the like can be used. The set G of the S pole and the N pole and the four divided portions 990 are embedded in the concave portion 126 of the ring 110 and arranged.
Each divided portion 990 is a portion that does not generate magnetism, and the magnetism detection sensor 150 is a so-called magnetically insensitive region that does not detect magnetism. The magnets 130 are arranged at equal intervals along the circle 99 of the ring 110. 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.

One magnetic detection sensor 150 in FIG. 5 is positioned slightly away from the rotating body 120. In the example of FIG. 3, the substrate 150C is
Holds 0. The substrate 150C is attached to, for example, the lens barrel 18 side. This magnetic detection sensor 1
For example, a Hall element can be used for 50. The magnetic detection sensor 150 sequentially rotates the magnets 130 as the rotating body 120 rotates in the direction of R1 or R2.
When the N pole and S pole of the
Is a sensor that detects the magnetism of Rotating body 120 of FIG.
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.

Magnetic detection sensor 1 as shown in FIGS. 7 and 8
The detection output S of the signal processing unit 30 shown in FIGS.
Sent to 0. The signal processing unit 300 corresponds to FIG.
Is detected, whether the rotating body 120 shown in FIG. 4 is rotating in the first direction R1 or not in the second direction R2.
Is determined, and the number of the N and S poles of the magnet 130 passing through the magnetic detection sensor 150 is counted, whereby the rotation position of the rotating body 120 in the first direction R1 or the second direction R2 is determined. That is, the rotation amount is detected. In addition, the rotation speed is obtained from the number of pulses per unit time as needed. Such information on the rotation direction of the rotating body 120 and the position (the amount of rotation) of the rotating body 120 is supplied as information to the computer 400 in FIG. 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, as shown in FIG. 6, the formation angle α ° of the N pole and the S pole of each magnet 130 is the same.

The Hall element used as one magnetic detection sensor 150 is a magneto-electric conversion element,
This converts the magnetic quantities of the N and S poles into electrical quantities (Hall output), and includes InAS-based, GaAs-based, and InSb-based. As the magnet 130, for example, a magnet in which a magnetic material is included in rubber, a magnet in which a magnetic material is included in plastic, or a magnet such as a sintered magnet can be used. Further, a liquid magnet may be used as the magnet. This liquid magnet is formed by being injected into a 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. 8 shows a circuit example of one magnetic detection sensor 150 shown in FIG. Magnetic detection sensor 150
Are mounted on the substrate 150C. One magnetic detection sensor 150 includes a sensor unit 400 and an amplification unit 410. The sensor unit 400 is a Hall element as described above.
When the magnetism of the pole is detected, it is converted into a magnetic-electric signal and sent to the input side of the amplifier 410.

The magnetic detection sensor 150 has a reference voltage Vc
c, the voltage output unit Vout, and the ground GND. As shown in FIG. 8, the sensor unit 400 and the amplification unit 410 of the magnetic detection sensor 150 are mounted on one substrate 150C. However, as shown in FIG. 9, the sensor unit 400 of the magnetic detection sensor 150 may be mounted on a substrate 150C, and the amplifying unit 410 may be mounted on another substrate 150R or incorporated in a microcomputer.

FIG. 10 shows a ring 110 and a ring 110.
FIG. 4 is a cross-sectional view showing a structural example of a magnet 130 facing the circumstance. A ring-shaped magnet 130 is fixed to the surface 110A of the ring 110 by embedding. One magnetic detection sensor 150 is arranged facing the ring-shaped magnet 130. Magnetic detection sensor 15
The gap e between 0 and the magnet 130 is, for example, 0.5 mm
However, if the mechanical accuracy can be maintained, it may be smaller. Conversely, if the detection output is sufficiently high, it may be wider.

FIG. 11 is an enlarged view of a portion A of FIG. 10, and the magnetic detection sensor 150 is, for example, a Hall IC.
And the magnetic detection sensor 150
The terminal 700 is electrically connected to the conductor 150D of the substrate 150C via the terminal 700 using the soldering portion 150E. In this case, in order to reduce the size, a part of the magnetic detection sensor 150 is held in the hole 730 of the substrate 150C so as to enter. Also, the magnet 130
The positioning is performed 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
For example, it is attached to the bottom surface of the concave portion 126 of the ring 110 using a double-sided tape 139. However, instead of using the double-sided tape 139 in this manner, the ring 110 is sandwiched by using a material such as an iron plate to sandwich the magnet 130.
Of course, it may be fixed to the concave portion 126 of FIG. FIG. 12 shows the magnetic detection sensor 150 mounted on the substrate 150C.

Next, an example of use of the lens barrel 18 provided with the above-described rotation detecting device 100 will be described. The user holds the video camera recorder 10 shown in FIGS. 1 and 2 by hand, holds the manual ring 110 shown in FIGS. 3 and 4, and moves the ring 110 and the rotating body 120 in the R1 direction shown in FIG. Alternatively, it rotates appropriately in the direction of R2. Thus, manual focus adjustment in the lens barrel 18 is performed.

When the ring 110 and the rotating body 120 are rotated, the manual focus lens 31 performs focus adjustment by moving forward and backward along the optical axis OL. At this time, FIG.
The magnetic detection sensor 150 outputs a detection output S to the signal processing unit 300. For example, in FIG.
The detection output S is counted by the signal processing unit 300 of FIG. 7 by counting the waveform of the detection output S, and according to the number of S poles and N poles of the magnet 130 shown in FIGS.
The rotation amount in the R1 direction or the R2 direction can be detected.

Next, the detection of the rotation direction of the rotating body 120 will be described with reference to FIGS. FIG.
(A) shows the output waveform SW of the detection output S when the rotating body 120 in FIG. 5 rotates in the R1 direction. FIG.
7B shows an output waveform SW1 of the detection signal S when the rotating body 120 in FIG. 5 is inverted in the direction of R2. As described above, the output waveforms SW and SW1 in both the forward rotation and the reverse rotation
Has a substantially sawtooth shape, but the output waveforms SW and SW1 have inverted waveforms.

Further, as shown in FIG. 5 and FIG. 6, the magnet 130 has a dividing portion 9 between a pair G of adjacent S and N poles.
Since the 90 is provided, the shape of the output waveform SW shown in FIG. 17A is different from that of the accurate sine waveform, and the rising portion 980 and the falling portion 981 of the output waveform SW have different slopes. Similarly, the output waveform SW of FIG.
Also in 1, the inclination angle of the ascending portion 982 and the descending portion 983 are different. In FIG. 17A, the time when the rising portion 980 crosses the reference voltage v0 is defined as t1, and the time when the maximum value is reached is defined as t2. The time when the falling part 981 crosses the reference voltage v0 is defined as t3. FIG.
In (B), times t1, t2, and t3 are set in the same manner. Such time setting processing is performed by the signal processing unit 3 shown in FIG.
00 performs. Note that the reference voltage v0 is a value obtained by adding the maximum value MAX and the minimum value MIN and dividing by 2 as shown in FIG.

FIG. 18 (A) shows such time t1, t
After setting t2 and t3, the rotating body 120 of FIG.
It is a flowchart for judging whether it is normal rotation like (A) or reverse as shown in FIG.17 (B). As an example, the output waveform SW at the time of normal rotation in FIG. 17B will be described. However, the output waveform SW at the time of inversion in FIG.
1 can be similarly performed. Step ST1
In FIG. 17A, the value of the output waveform SW shown in FIG. 17A is converted from analog to digital, and when the digital value exceeds the reference voltage v0, the value of the output waveform SW becomes the reference voltage v0.
Is assumed to have crossed, and the time is set to t1. Next, in step ST2, the value of the output waveform SW becomes the maximum value MA.
It is determined whether or not X has been reached, and when the maximum value has been reached, the time is set to t2.

Next, in step ST3, the output waveform S
It is determined whether or not the value of W has become equal to or lower than the reference voltage v0. If the value has become equal to or lower than the reference voltage v0, the time is set to t3. In step ST4, the computer 400 of FIG. 7 compares the value of (t2-t1) with the value of (t3-t2). The result of this comparison (t2-t1) is (t3-t
If it is larger than 2), as shown in FIG. 17A, the computer 400 in FIG. 7 can consider that the rotating body is rotating forward in the R direction. Instead, (t3
If (−t2) is larger than (t2−t1), the computer 400 in FIG. 7 can regard that the rotating body is reversed in the direction of R2 as illustrated in FIG. 17B.

As described above, FIGS. 17A and 17B
By judging the output waveforms SW and SW1 of FIG. 18 based on the flowchart of FIG. 18, the computer 400 of FIG. 7 can reliably know whether the rotating body is rotating forward or inverting. Moreover, by knowing the values of the times t1, t2, and t3, the rotation speed of the rotating body can also be known.

Next, another embodiment of the present invention will be described with reference to FIG. The rotating body 120 in FIG. 19 shows the upper half for simplification of the drawing. Rotating body 120
In the magnet 130, a notch-shaped divided portion 1990 is formed between the set G of the S pole and the N pole. The size of these divisions 1990 is set larger than the size of the magnetic detection sensor 150. A neutral zone NZ for separating the north pole and the south pole is formed between the north pole and the south pole of the adjacent sets G, G. Even in this case, the magnetic detection sensor 150 outputs the output waveform S as shown in FIG. 17 in the same manner as providing the division unit 990 as shown in FIG.
W and SW1 can be output.

FIGS. 20 to 22 show still another embodiment of the present invention. In the magnet 130 shown in FIG. 20, a notch-shaped divided portion 2990 is formed between the adjacent pairs of N and S poles G, G. This division 2990
Is larger than the size of the magnetic detection sensor 150. The shape of the divided portions 1990 and 2990 in FIGS. 19 and 20 may be, for example, a substantially square shape, a substantially rectangular shape, or another shape.

In FIG. 21, adjacent pairs of S and N poles G,
Between G, a rectangular or square division 3990 is formed. 19 is formed on the inner peripheral side of the magnet 130, and is divided into two parts in FIG.
990 is formed on the outer peripheral side of the magnet 130.
On the other hand, the dividing unit 3990 in FIG.
It is formed inside 30 and is not open outside or inside magnet 130.

In still another embodiment shown in FIG. 22, this division 4990 is formed.
Is, for example, circular or elliptical. FIG. 21 and FIG.
The size of the two divisions 3990 and 4990 is larger than the size of the magnetic detection sensor 150.

Next, another embodiment of the present invention will be described with reference to FIGS. In the embodiment of FIG. 13, 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 shown in FIG. 14, a ring 110 has a recess 110Y. The magnet 130 is fixed to the recess 110Y using, for example, a double-sided tape 800. As is apparent from a comparison between FIG. 13 and FIG. 14, the concave portion 110X of the ring 110 is opened to the outer peripheral side in FIG. 13, but the concave portion 110X is not opened to the outer peripheral side in FIG. Therefore,
The inner peripheral surface of the magnet 130 is the inner peripheral surface 12 of the ring 110.
Positioned at 0X. In FIG. 14, the outer peripheral surface of the magnet 130 is positioned by the inner peripheral surface 110Z of the ring 110.

In the embodiment shown in FIG. 15, 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. 16, the magnet 130 is embedded and fixed in the recess 150X of the ring 110. On the other hand, the magnetic detection sensor 150 is embedded in the hole 150F of the substrate 150C.

In the embodiment of the present invention, one magnetic detection sensor 15 is used as compared with the case where a conventional optical sensor is used.
By using 0, the thickness can be extremely reduced in the direction of the optical axis OL in FIG. 5, 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,
Of course, the magnet may be a rubber magnetized with a magnetic material included, a plastic magnetized with a magnetic material included, or a sintered magnet.

The substrate 150C to which one magnetic detection sensor 150 shown in FIG. 5 is fixed may be a normal printed wiring board or a flexible printed wiring board. The magnetic detection sensor, as described above,
The substrate 150C is provided with two holes, and is 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, since the rotation detecting device 100 has one magnetic detection sensor 150, it can check the waveform of the detection output S shown in FIG. However, it is also possible to detect the rotation direction of whether it is rotating in the first direction R1 or in the second direction R2. In the present invention, since the waveform of the detection output appearing as a sine wave is distorted in the time axis direction, the waveform changes depending on the rotation direction. At this time, as shown in FIG.
With respect to the reference voltage v0 which is set to て by adding the sampled maximum value and minimum value, t1 and t3 crossing v0 and a maximum value (or a minimum value) t2 are obtained, and (t2−t1)
By calculating and comparing (t3−t2), it can be determined whether the rotation is normal rotation or inversion. In addition, the rotation speed can be calculated thereby.

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.

By using the rotation detecting device and the lens barrel having the rotation detecting device according to the present invention, the rotation detecting device and the lens barrel can be reduced in size, thickness, and power consumption. Therefore, the reliability of the rotation detecting device and the reliability of the lens barrel can be improved.

[0053]

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 illustrates an example of a magnetic detection sensor, a signal processing unit, and a computer.

FIG. 8 is a diagram illustrating a circuit example of a magnetic detection sensor.

FIG. 9 is a diagram showing another circuit example of the magnetic detection sensor.

FIG. 10 is a diagram showing a ring, a magnet, and a magnetic detection sensor.

FIG. 11 is an enlarged view showing a portion A in FIG. 10;

FIG. 12 is a diagram showing a mounting example of a magnetic detection sensor.

FIG. 13 is a diagram showing another embodiment of the present invention.

FIG. 14 is a view showing still 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 diagram illustrating an example of an output waveform when the rotating body is rotating forward and when rotating.

FIG. 18 is a diagram showing an example of detecting the normal rotation and the reverse direction of the rotating body.

FIG. 19 is a view showing another embodiment of the magnet of the present invention.

FIG. 20 is a view showing still another embodiment of the magnet of the present invention.

FIG. 21 is a view showing still another embodiment of the magnet of the present invention.

FIG. 22 is a view showing still another embodiment of the magnet of the present invention.

FIG. 23 is a view showing an example of a conventional lens barrel.

FIG. 24 is a diagram showing a rotation detection device in a conventional lens barrel.

FIG. 25 is a diagram showing a light emitting unit and a light receiving unit of a conventional rotation detecting device.

FIG. 26 is a diagram illustrating a circuit example of a photointerrupter of a conventional rotation detecting device.

[Explanation of symbols]

18 ... lens barrel, 99 ... circle, 100
..Rotation detectors, 120 ... rotors, 130 ...
Magnet, 150 ... magnetic detection sensor, R1 ...
First direction, R2 ... second direction, OL ... center of rotation (optical axis)

Continuation of the front page (72) Inventor Katsuyuki Yoshiike 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2F077 AA36 AA37 AA43 AA49 CC02 JJ02 JJ08 JJ23 TT06 TT32 TT32 TT55 TT58 TT59 TT66 VV02 VV10 VV11 VV23 VV35 WW03 2H044 DA01 DB01 DE06

Claims (12)

[Claims] 1. A rotation detecting device for detecting rotation of an object, a rotating body that holds the object and is rotatable in a first direction and a second direction opposite to the first direction; A set of S poles and N poles arranged on the rotating body along a circle about the center of rotation of the body, wherein the set of S poles and N poles and the set of adjacent S poles and N poles A rotation detecting device comprising: a magnet having a divided portion that does not generate magnetism; and one magnetic detection sensor that detects magnetism of the S pole and the N pole of the magnet. 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 rotation detecting device according to claim 1, wherein the magnetic detection sensor is a Hall element, and an amplifier for amplifying an output waveform of the Hall element is arranged at the same position as the Hall element or at another position. apparatus. 4. The rotation detecting device according to claim 1, wherein the divided portion of the magnet is a notch. 5. The rotation detecting device according to claim 1, wherein the divided portion of the magnet is a non-magnetic portion. 6. The output waveform of the Hall element has a saw-tooth shape, and a rotation direction of the rotating body is detected by comparing a time of a rising part and a time of a falling part of the output waveform. Rotation detection device. 7. A lens barrel having a rotation detection device for detecting rotation of an object, wherein the rotation detection device holds the object and holds a second direction opposite to the first direction and the first direction. A rotating body rotatable in a direction, a set of S poles and N poles arranged in the rotating body along a circle centered on the rotation center of the rotating body, and the set of S poles and N poles And a magnet having a divided portion that does not generate magnetism between the pair of the S pole and the N pole adjacent to the magnet, and one magnetic detection sensor that detects the magnetism of the S pole and the N pole of the magnet. A lens barrel having a rotation detecting device. 8. The lens barrel having the rotation detecting device according to claim 7, wherein the object is a focus lens for manual operation arranged in the lens barrel. 9. The rotation detection device according to claim 7, wherein the magnetic detection sensor is a Hall element, and an amplifier for amplifying an output waveform of the Hall element is arranged at the same position as the Hall element or at another position. Lens barrel with device. 10. The lens barrel having the rotation detecting device according to claim 7, wherein the divided portion of the magnet is a notch. 11. The lens barrel according to claim 7, wherein the divided portion of the magnet is a non-magnetic portion. 12. The rotation direction of the rotator according to claim 9, wherein the output waveform of the Hall element has a saw-tooth shape, and a rotation direction of the rotating body is detected by comparing a time of a rising part and a time of a falling part of the output waveform. A lens barrel having the rotation detecting device.