JPH0943480A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens device capable of performing focusing operation to be performed by the movement of a lens in an optical axis direction by means of a piezoelectric actuator arranged inside a lens barrel. SOLUTION: This lens device constituted of a first lens 72, a main mirror 74, a sub-mirror 81, a second lens 77, and a third lens 78; the piezoelectric actuator 82 performs the focusing operation by directly moving the mirror 81 in the optical axis direction. When electrical wiring 96 formed on a film surface and connecting the actuator 82 with a driving circuit 95 is on a position where the wiring 96 crosses a luminous flux inside the lens device, the film surface formed on the wiring 96 is arranged to be in parallel with the luminous flux, so that the range of incident light shielded by the wiring 96 is kept to a minimum. The wiring 96 is formed on a flexible transparent film by print or is formed on a flexible film by the print and reflection preventing treatment is performed on its surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device, and more particularly, to a lens device using a piezoelectric actuator for moving optical elements such as a lens group and a reflecting mirror constituting an optical system, and particularly to the actuator. The present invention relates to the configuration and arrangement of electrical wiring that connects the drive circuit and

[0002]

2. Description of the Related Art A conventional zoom lens is composed of a lens group dedicated to zooming and a lens group dedicated to focusing. However, in recent years, the lens group is dedicated to zooming and dedicated to focusing. A zoom lens called a Varifocal optical system has been developed that can increase the zoom ratio and shorten the closest distance by using the zoom lens group for focusing without dividing the functions as described above. Has been done.

FIG. 24 shows a conventional variable focal length optical system.
FIG. 4 is a cross-sectional view taken along the optical axis direction, showing an example of a mullens. In FIG. 24, 101 is a lens outer cylinder, and 102
Is a zoom operation ring 10 which is rotatable on the lens outer cylinder 101.
A fixed inner cylinder 3 is fixed to the lens outer cylinder 101. A zoom cam ring 104 is fitted on the outer side of the fixed inner cylinder 103. An annular groove 10 is provided near one end of the zoom cam ring 104.
4a is formed and engages with the annular projection 103a formed on the outer side of the fixed inner cylinder 103, so that the zoom cam ring 104 is rotatable on the outer side of the fixed inner tube 103 and does not move in the optical axis direction. It is supported.

The zoom lens is composed of four lens groups. The first lens group L1 is the holding frame 105, the second lens group L2 is the holding frame 106, and the third lens group L3 is the holding frame 10.
7, the fourth lens unit L4 is held by the holding frame 108.

A pin 10 is provided near one end of the zoom cam ring 104.
4p is provided, and this pin 104p is a zoom operation ring 10.
Since it is engaged with No. 2, the rotational operation of the zoom operation ring 102 is transmitted to the zoom cam ring 104. First lens unit L1
The pin 105p provided on the holding frame 105 is located at the intersection of the cam groove 104c of the zoom cam ring 104 and the rectilinear groove 103b of the fixed inner cylinder 103, and passes through the cam groove 104c of the zoom cam ring 104. Straight groove 103b of the fixed inner cylinder 103
Is engaged. With this configuration, the zoom operation ring 102
The rotation of the zoom cam ring 104 by the rotation operation of
05p is moved along the rectilinear groove 103b of the fixed inner cylinder 103, and the first lens group L1 held by the holding frame 105 is moved.
Is moved in the optical axis direction.

Further, the holding frame 107 of the third lens unit L3 is provided with a pin 107p, and the straight groove 1 of the fixed inner cylinder 103 is provided.
03d through the cam groove 104d of the zoom cam ring 104
Is engaged. With this configuration, when the zoom cam ring 104 rotates, the pin 107p is fixed to the straight groove 103 of the fixed inner cylinder 103.
The third lens unit L3 held by the holding frame 107 is moved in the optical axis direction by moving along the distance d.

Further, the holding frame 107 of the third lens unit L3
A zoom cam ring 109 is fitted on the outer side of the. Z-
An annular protrusion 109 a is formed near one end of the muckum ring 109, and the annular groove 1 formed outside the holding frame 107
07a, the zoom cam ring 109 is supported rotatably outside the holding frame 107 and movable integrally with the holding frame 107 in the optical axis direction.

The pin 104q provided near one end of the zoom cam ring 104 is a straight groove 1 of the zoom cam ring 109.
The rotation of the zoom cam ring 104 is transmitted to the zoom cam ring 109, which causes the zoom cam ring 109 to rotate. Pin 1 is attached to the holding frame 108 of the fourth lens unit L4.
08p is provided, penetrates the rectilinear groove 107b of the holding frame 107 of the third lens unit L3, and engages with the cam groove 109a of the zoom cam ring 109. With this configuration, the rotation of the zoom cam ring 104 is controlled by the zoom cam ring 109 via the pin 104q.
The rotation of the zoom cam ring 109 causes the pin 108p of the holding frame 108 of the fourth lens unit L4 to move straight along the straight-moving groove 107b of the holding frame 107, and the fourth lens unit L4 with respect to the holding frame 107. Move in the optical axis direction.

A mount portion 110 for mounting the lens on the camera body is formed at the right end of the lens outer cylinder 101, and a default detected by a focus detection device on the camera body side.
A coupler 111 which is coupled to a drive mechanism arranged on the camera body side for driving the lens group to the in-focus position based on the amount of dust.
Is arranged. Pinion 111a of coupler 111
Meshes with a gear formed on the outside of the helicoid ring 112 having a helicoid screw 112a on the inner surface thereof, and the coupler-1
The rotation of 11 causes the helicoid ring 112 to rotate. Also,
One end 113b of the manual operation ring 113 arranged inside the lens outer cylinder 101 is engaged with a pin 112b planted in the helicoid ring 112, and the manual operation ring 1
When rotating 13, the helicoid ring 112 can be rotated.

The focus cam ring 114 is a fixed inner cylinder 103.
The helicoid screw 114a is formed at one end thereof and is engaged with the helicoid screw 112a of the helicoid ring 112.

The holding frame 106 of the second lens unit L2 is provided with a pin 106p, which penetrates the cam groove 114a of the focus cam ring 114 and the rectilinear groove 103e of the fixed inner cylinder 103, and the cam of the zoom cam ring 104. It is engaged with the groove 104e.

With the above construction, when the helicoid ring 112 is rotated by the rotation of the coupler 111, the focus cam ring 114 connected to this by the helicoid screw and the holding frame 106 connected to this by the pin 106p. By moving in the optical axis direction, the second lens unit L2 can be moved in the optical axis direction. Further, also by the rotation of the zoom cam ring 104, the holding frame 106 connected by the pin 106a can be moved in the optical axis direction, and the second lens unit L2 can be moved in the optical axis direction.

FIG. 25 is a sectional view of a lens barrel of a conventional reflective telephoto lens capable of autofocus.
In the figure, 201 is a first lens, 221 is a primary mirror, 22
Reference numeral 1a denotes a reflecting surface formed on the back surface of the main mirror 221, 202 denotes a sub mirror, 202a denotes a reflecting surface formed on the back surface of the sub mirror 202, 222 denotes a second lens, and 223 denotes a third lens.
A focusing lens group 203 including a first lens 201 and a secondary mirror 202 is held by a helicoid ring 204, and a focusing lens ring 205 and a distance scale ring 206 are used to connect a focusing lens group 203 from the camera body side (not shown). AF receiving driving force
A gear is provided outside the optical axis so as to mesh with the pinion gear 212 of the reduction mechanism 207 connected to the coupler 208.

The deceleration mechanism 207 comprises a coupler gear 210, an intermediate gear 211, and a pinion gear 212 provided on the drive shaft 209.

The primary mirror holding frame 215 has a pinion gear 212.
And a bearing for the intermediate gear 211 are provided, and the distance scale ring 206
There is also a bearing part for receiving the. The other bearing that supports the shafts of the pinion gear 212 and the intermediate gear 211 is provided on the gear base plate 213 and is fixed to the lens barrel.

The driving force from the camera body side is AF coupler
It is transmitted to the speed reduction mechanism 207 via 208, the drive shaft 209, and the coupler gear 210, and the helicoid ring 204 is rotated through the focus interlocking ring 205 to move the focusing lens group 203 in the optical axis direction for focusing. Is configured to be performed.

[0017]

As described above,
In the conventional zoom lens of the variable optical system and the reflective telephoto lens of the autofocus system, the zoom lens is coupled to the motor driven by the defocus signal detected by the focus detection device on the camera body side. A coupler is provided on the lens side, and the helicoid ring is rotated by the rotation of the coupler to move a predetermined lens group to the in-focus position.

However, in the case of such a configuration, since the rotational movement of the helicoid ring is converted into the linear movement of the focus cam ring by the helicoid screw,
The structure is complicated, and as a result, there are inconveniences such as an increase in the number of parts and an increase in weight, and improvement thereof has been demanded.

Further, a means for using an actuator arranged in the lens barrel to move the lens group contributing to focusing is proposed. In this case, a drive for driving the actuator in the lens barrel is proposed. It is required to arrange the circuit so that the electric wiring connecting the actuator and the drive circuit does not affect the luminous flux passing through the lens barrel. An object of the present invention is to solve the above problems.

[0020]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Among the lenses composed of a plurality of lens groups, a lens that contributes to focusing is provided by an actuator in which light is emitted by an actuator. In a lens device that performs a focusing operation by moving in the axial direction, an electro-mechanical conversion element and an electro-mechanical conversion element that are disposed along the optical axis direction and are coupled to the electro-mechanical conversion element and displaced together. A driving member and a supporting frame of the lens group that contributes to focusing are coupled, and an actuator composed of a moving member frictionally coupled to the driving member, and an electromechanical conversion element of the actuator. A driving circuit for driving the electric-mechanical conversion element of the actuator; and an electric wiring formed on a film surface for connecting the driving circuit to each other. When the wire is in position across the light beam in the lens apparatus, the film surface formed of electric wires, characterized in that it is arranged parallel to the light beam.

The electric wiring formed on the film surface for connecting the electro-mechanical conversion element and the driving circuit is formed on the flexible transparent film by printing, or is formed on the flexible film. It may be formed by printing and the surface thereof may be subjected to antireflection treatment.

[0022]

An actuator using an electromechanical conversion element is used for focusing operation. The electric wiring formed on the film surface for connecting the electro-mechanical conversion element and the drive circuit has a structure in which the film surface on which the electric wiring is formed has the luminous flux when the electric wiring crosses the luminous flux in the lens device. Since it is arranged so as to be parallel to, it is possible to minimize the range of the light flux blocked by the electrical wiring.

[0023]

Embodiments of the present invention will be described below. [Overall Structure of Zoom Lens Device] FIGS. 1 and 2 show the structure of a zoom lens device according to a first embodiment of the present invention. FIG. 1 is a sectional view of the lens apparatus 1 taken along the optical axis direction, and FIG. 2 is a piezoelectric actuator of the lens apparatus shown in FIG.
FIG. 3 is a perspective view showing a drive mechanism portion of a computer.

In FIG. 1, reference numeral 1 is a lens outer cylinder, 2 is a zoom operating ring rotatable on the lens outer cylinder 1, and 3 is a fixed inner cylinder fixed to the lens outer cylinder 1. A zoom cam ring 4 is fitted on the outer side of the fixed inner cylinder 3. An annular groove 4a is formed near one end of the zoom cam ring 4 and engages with an annular projection 3a formed on the outer side of the fixed inner cylinder 3, and the zoom cam ring 4 is placed on the outer side of the fixed inner tube 3. It is rotatably supported so as not to move in the optical axis direction.

The zoom lens is composed of four lens groups. The first lens group L1 is on the holding frame 5, and the second lens group L2.
Is held by the holding frame 6, the third lens group L3 is held by the holding frame 7, and the fourth lens group L4 is held by the holding frame 8.

A pin 4p is provided near one end of the zoom cam ring 4, and the pin 4p is engaged with the zoom operation ring 2, so that the rotation operation of the zoom operation ring 2 is performed by the zoom cam ring. 4 is transmitted. The pin 5p provided on the holding frame 5 of the first lens unit L1 is located at the intersection of the cam groove 4c of the zoom cam ring 4 and the rectilinear groove 3b of the fixed inner cylinder 3, and the cam groove of the zoom cam ring 4 is formed. It passes through 4c and is engaged with the straight groove 3b of the fixed inner cylinder 3. With this configuration, the rotation of the zoom cam ring 4 due to the rotation operation of the zoom operation ring 2 moves the pin 5p along the rectilinear groove 3b of the fixed inner cylinder 3 and is held by the holding frame 5. The lens unit L1 is moved in the optical axis direction.

A pin 7p is attached to the holding frame 7 of the third lens unit L3.
And a groove 13e of the focus cam ring 13 described later.
Through the straight groove 3d of the fixed inner cylinder 3 and engages with the cam groove 4d of the zoom cam ring 4. With this configuration,
The rotation of the zoom cam ring 4 moves the pin 7p along the rectilinear groove 3d of the fixed inner cylinder 3 and the third frame held by the holding frame 7 is moved.
The lens unit L3 is moved in the optical axis direction.

Further, a zoom cam ring 9 is fitted on the outside of the holding frame 7 of the third lens unit L3. An annular projection 9a is formed near one end of the zoom cam ring 9 and engages with an annular groove 7a formed on the outside of the holding frame 7, so that the zoom cam ring 9 is rotatable outside the holding frame 7. And is supported so as to move in the optical axis direction integrally with the holding frame 7.

A pin 4q provided near one end of the zoom cam ring 4 penetrates the slit 3s of the fixed inner cylinder 3,
It engages with the rectilinear groove 9b of the zoom cam ring 9, and the rotation of the zoom cam ring 4 is transmitted to the zoom cam ring 9 to rotate the zoom cam ring 9. A pin 8p is provided on the holding frame 8 of the fourth lens group L4 and penetrates through the rectilinear groove 7c of the holding frame 7 of the third lens group L3 to engage with the cam groove 9c of the zoom cam ring 9.

With this structure, the rotation of the zoom cam ring 4 is transmitted to the zoom cam ring 9 via the pin 4q, and the rotation of the zoom cam ring 9 holds the pin 8p of the holding frame 8 of the fourth lens unit L4. The frame 7 is moved straight along the straight groove 7c, and the fourth lens unit L4 is moved in the optical axis direction with respect to the holding frame 7. In addition,
As described above, the rotation of the zoom cam ring 4 also moves the third lens unit L3 held by the holding frame 7 in the optical axis direction.

A piezoelectric actuator 12 for driving a focus cam ring 13 is arranged near the left end of the fixed inner cylinder 3. The structure of the piezoelectric actuator 12 will be described with reference to FIGS. 1 and 2. The fixed inner cylinder 3 is provided with two support members 3f and 3g, and the drive shaft 12b is supported movably in the optical axis direction. One end of the piezoelectric element 12a is bonded and fixed to the end of the drive shaft 12b.
The other end of a is bonded and fixed to the flange portion 3h of the fixed inner cylinder 3. The drive shaft 12b is displaced in the optical axis direction by the displacement of the piezoelectric element 12a in the thickness direction.

As is apparent from FIG. 2, the fo
The cascum ring 13 has a cutout portion 1 to the right of the center thereof.
3g is formed, and a contact portion 13a through which the drive shaft 12b penetrates is formed near the center of the cutout portion 13g.
A notch groove 13b exposing the drive shaft 12b is formed in the contact portion 13a, and a pressure contact spring 13c is provided in the notch groove 13b.
Is arranged so as to straddle the drive shaft 12b. The drive shaft 12b and the pressure contact spring 13c are in pressure contact with each other, and the drive shaft 12b and the contact portion 13a are also in pressure contact with each other so that they are frictionally coupled with each other by an appropriate friction force.

Although the operation will be described in detail later, as shown in FIG. 3, a drive pulse having a gentle rising portion and a rapid falling portion is supplied to the piezoelectric element 12a to cause displacement in the thickness direction and drive. When the shaft 12b is displaced in the optical axis direction,
The focus cam ring 13 frictionally coupled to the drive shaft 12b at the contact portion 13a moves in the optical axis direction in the direction indicated by the arrow a.
Further, in order to move the piezoelectric element 12a in the direction opposite to the arrow a, a drive pulse having a rapid rising portion and a gentle falling portion may be supplied to the piezoelectric element 12a.

A pin 6p is provided on the holding frame 6 for holding the second lens unit L2. The pin 6p penetrates the cam groove 13d of the focus cam ring 13 and the rectilinear groove 3j of the fixed inner cylinder 3, -It is engaged with the cam groove 4j of the cam cam ring 4.

With the above construction, the piezoelectric actuator 12 is driven based on the amount of defocus detected by the focus detection device on the camera side or the amount of operation of the later-described focusing ring, and the focusing cam ring is driven. When 13 is moved in the optical axis direction, the pin 6p penetrating the cam groove 13d of the focus cam ring 13 moves the holding frame 6 in the optical axis direction, so that the second lens unit L2 detects the detected defocus amount. It is possible to set the in-focus position by moving in the optical axis direction by a distance according to.

Further, due to the rotation of the zoom cam ring 4, the holding frame 6 connected by the pin 6p moves in the optical axis direction,
The second lens unit L2 can also be moved in the optical axis direction by zooming. [Focus Correction of Lens] FIG. 4 shows the movement loci of the first lens unit L1 to the fourth lens unit L4 during zoom operation. The lenses of each unit have the set focal length f at the wide-angle end. In response to the change from f1 to the telephoto end f2, the lens moves as shown in FIG.

At this time, the amount of extension of the second lens unit L2 is non-linearly changed according to the focal length f and the photographing distance D set on the lens by the zoom operation to perform focus correction. FIG. 5 shows the set focal length f, shooting distance D,
Also, in the figure showing the relationship between the second lens group L2 and the amount of extension d, the amount of extension d increases as the subject is in the closer position and the focal length f set in the lens is on the telephoto side. That is, when the subject is at the closest position (D = Da), when the focal length f is at the wide-angle end f1, the extension amount d
Is d1 and the extension amount d is d2 when the focal length f is at the telephoto end f2.

The shape of the cam groove 4j of the zoom cam ring 4 for moving the second lens unit L2, the shape of the cam groove 13d of the focus cam ring 13, and the movement of the pin 6p located at the intersection of the groove 4j and the groove 13d. The state will be described with reference to the development view shown in FIG.

In FIG. 6, the solid line indicates the cam of the zoom cam ring 4 when the focal length f set on the lens is at the wide-angle end f1 and the shooting distance is set to infinity (D = ∞). Position of groove 4j (4j-1) and focus cam ring 13
The position (13d-1) of the cam groove 13d is shown. Also, the alternate long and short dash line shows the cam groove 4j of the zoom cam ring 4 when the focal length f set on the lens is at the telephoto end f2 and the shooting distance is set at the closest position (D = Da). Position of
(4j-2) and the position (13d-2) of the cam groove 13d of the focus cam ring 13.

That is, in the zoom operation, the zoom cam ring 4 is moved when the focal length f set on the lens is at the wide-angle end f1 in the state where the photographing distance is set to infinity (D = ∞). When operated to the telephoto side, the cam groove 4 of the zoom cam ring 4
j moves from position (4j-1) to position (4j-2) (moves from left to right in FIG. 6). At this time, the focus ring 13
Does not move, so pin 6p is from position (6p-1)
Zooming operation is performed by moving to (6p-2).

In the focus operation, when the focal length f set on the lens is at the wide-angle end f1, the focus is set to infinity (D = ∞).
When the cascam ring 13 is operated to the short distance side, the cam groove 13d of the focus cascam ring 13 moves from position (13d-1) to position
Move to (13d-2) (move from bottom to top in FIG. 6). At this time, since the zoom cam ring 4 does not move, the pin 6p moves from the position (6p-1) to the position (6p-3) (feed amount d = d1), and the desired focusing operation is performed.

Further, when the focal length f set on the lens is at the telephoto end f2, the photographing distance is infinity (D
= ∞), if the focus cam ring 13 is operated to the short distance side, the cam groove 1 of the focus cam ring 13
3d moves from position (13d-1) to position (13d-2) (moves from bottom to top in FIG. 6). At this time, since the zoom cam ring 4 does not move, the pin 6p moves from the position (6p-2) to the position (6p-4) (feed amount d = d2), and the desired focusing operation is performed.

The infinite position of the focus lens ring 13 (D =
The amount of movement from (∞) to the closest position (D = Da) is constant, but the amount of extension of the pin 6p, that is, the amount of extension of the second lens unit L2, is extended when the focal length f is at the wide-angle end f1. Amount d = d1, and when it is at the telephoto end f2, the feed amount d = d
2, the amount of extension of the second lens unit L2 is corrected according to the shooting distance.

For example, the photographing distance is the closest position (D = Da
), Set the zoom cam ring 4 to the wide-angle end f1.
From the telephoto end f2, the pin 6p will move to the position (6p-
Since the second lens unit L2 is moved to the position (6p-4) from the position 3) and the amount of extension d = d2 is given to the second lens unit L2, no focus shift occurs even by the zoom operation.

As described above, according to the present invention, the lens of the varifocal optical system is used. However, when the zoom operation is performed, the lens related to the focus is extended by the focus cam to perform the focus correction. It can be used exactly like a normal zoom lens.

As described above, regarding the lens focus correction,
The focal length f set on the lens is f1 at the wide-angle end and f at the telephoto end.
2. Shooting distance is at infinity (D = ∞) and closest (D)
= Da) position has been described, but the second lens unit L can be used at any focal length and shooting distance in the middle.
It goes without saying that the feeding amount of 2 is properly corrected. [Detection of lens position and MR sensor] In order to detect the position of the second lens unit L2 that is extended by the focusing operation, the focus cam ring 13 has a ferromagnetic thin film magnetoresistive element type position sensor (to be described later). Magnetoresistive element 2 (referred to as MR sensor)
1, a fixed inner cylinder 3 is provided with a magnetizing rod 22 in which N and S magnetic poles are magnetized at predetermined intervals.

Here, the MR sensor will be described. M
The R sensor is a non-contact type position sensor used for detecting a relatively long moving distance and position, and is composed of a magnetizing rod and a magnetoresistive element.

The principle will be described with reference to FIG. A magnetoresistive element 21 is mounted on a magnetizing rod 22 in which N and S magnetic poles are magnetized at predetermined intervals along the moving direction so that its current axis is perpendicular to the direction in which the magnetic poles are arranged. The faces are arranged parallel and close to the pole faces. Leakage magnetic flux is emitted from each magnetic pole as shown in FIG. 7, and acts on the magnetoresistive element 21 to cause the magnetoresistive effect described below.

That is, the magnetoresistive element 21 is magnetized by the magnetizing rod 22.
When there is between the magnetic poles, the resistance value decreases due to the magnetoresistive effect due to the horizontal component of the leakage magnetic flux, and there is no horizontal component of the leakage magnetic flux on the magnetic pole, so the resistance value of the magnetoresistive element 21 is a non-magnetic field The same as when When the magnetoresistive element 21 and the magnetizing rod 22 move relative to each other, the magnetoresistive element 2
Since the resistance value of 1 changes periodically, the moving distance, that is, the position can be known by counting the number of changes.

FIG. 8 is a diagram for explaining the magnetic pole spacing of the magnetizing rods forming the MR sensor, the specific arrangement of the magnetoresistive elements, and the output signal thereof. As shown in FIGS. 8A and 8B, the magnetic poles N and S of the magnetizing rod 22 are magnetized at a constant interval λ, and the resolution is determined by the dimension of the interval λ between the magnetic poles N and S.

As shown in FIG. 8 (c), the magnetoresistive element 21 has a pair of folded patterns of λ /
A-group magnetoresistive element MRa1 arranged at intervals of 2
And MRa2, and two b-group magnetoresistive elements MRb1 and MRb, which are also arranged as a pair at intervals of λ / 2.
Two sets of 2 are arranged at a distance d (d = λ / 4).
When the outputs of these magnetoresistive elements are processed by the output signal processing circuit of which an example is shown in FIG. 9, the output signals Va of the magnetoresistive elements MRa1 and MRa2 of the a group are shown in FIG. Since the waveforms of the output signals Vb of the magnetoresistive elements MRb1 and MRb2 of the and b groups are output with a phase difference of d, the moving direction can be known from this phase difference.

Output signal Va of the magnetoresistive element of group a
When the waveform Vb of the output signal of the magnetoresistive element of the b-group and the b-group is pulsed and synthesized by the pulse signal converter, a pulse signal of λ / 4 pitch is obtained as shown in FIG. By counting the pulse signals, the moving distance can be known with an accuracy of ¼ of the magnetic pole interval λ. [Manufacturing Function] Next,
The scrap mechanism will be described. In this embodiment, also in the multifunctional circus, the multifunctional circus ring 14 is used.
The piezoelectric actuator 12 is driven by electrically detecting the rotation angle by the operation (see FIG. 1), and the focus cam ring 1 is driven.
It employs a power focus mechanism that moves 3 in the direction of the optical axis.

That is, on the lens outer cylinder 1, an encoder pattern 1 for detecting the rotation angle of the manual focus ring 14.
4a, and an encod-
A brush 14b is provided which contacts the pattern 14a. For example, if an encoder pattern as shown in FIG. 10 is used, the rotation angle can be detected as a 4-bit pulse signal. Then, when the detected 4-bit pulse signal is processed by the pulse signal discriminating circuit shown in FIG. 11, a signal indicating the rotation direction and the rotation angle of the manual focus ring is obtained.

FIG. 12 shows a signal waveform processed by the pulse signal discriminating circuit shown in FIG. 11. The output signals of the four contacts of the brush 14b contacting the encoder pattern and the output signal of the inverter IV, An output signal of a chattering prevention circuit CH consisting of two pairs of flip-flops, an AND circuit,
The output signals X and Y of the processing circuit including the OR circuit and the flip-flop, the signal CW indicating the rotational direction of the manual focus ring, and the signal INT indicating the rotational angle are shown. [Control Circuit and Control Operation of Lens Device] FIG. 13 is a block diagram of the control circuit of the lens device. The control circuit includes a control unit 51 including a CPU, a pulse signal conversion unit 53 and an A / D conversion unit 54 for processing signals output from the MR sensor output amplification unit 52 connected to the input port thereof, and a multi-function unit. A pulse signal discriminating circuit 55 for processing the signal output from the dreg ring detector 56, and a piezoelectric actuator driver 57 connected to the output port. Further, an auto focus / manual focus on the camera side (not shown) is switched to an input port of the control unit 51.
The F / MF switching switch 61 and the focus detection circuit 62 are connected.

Next, the control operation of the control circuit for focusing the lens on the subject will be described with reference to FIGS. 13, 1 and 2. First, the control unit 51 detects a signal from the AF / MF switching switch 61 installed on the camera side (not shown). Here, autofocus, that is, AF / MF
It is assumed that the switching switch 61 is switched to the AF side.

The defocus signal for the object output from the focus detection circuit 62 on the camera side is input to the control unit 51. The control unit 51 judges the defocus signal, and when the lens L2, that is, the focus cam ring 13 needs to be moved in the direction of the arrow a, the piezoelectric actuator drive unit 57, as shown in FIG. The piezoelectric element 12a is driven by instructing the output of a drive pulse having a waveform consisting of such a gentle rising portion and a subsequent rapid falling portion.

At the gently rising portion of the drive pulse,
The piezoelectric element 12a gradually undergoes extension displacement in the thickness direction,
The drive shaft 12b is axially displaced in the direction of arrow a. Therefore, the focus ring 13 frictionally coupled to the drive shaft 12b at the contact portion 13a moves in the arrow a direction, and the lens L2 can move in the arrow a direction.

At the rapid fall portion of the drive pulse, the piezoelectric element 12a rapidly undergoes contraction displacement in the thickness direction, and the drive shaft 12b is also displaced axially in the direction opposite to the arrow a. At this time, the focus cam ring 13, which is frictionally coupled to the drive shaft 12b at the contact portion 13a, causes the drive shaft 12 to move due to its inertial force.
The focus ring 13 does not move because it overcomes the frictional force with b and remains substantially in that position.

The term "substantially" as used herein means that the focus ring 1 is in either the direction of arrow a or the direction opposite thereto.
It is meant to include those that follow the sliding contact portion 13a of No. 3 and the drive shaft 12b while slipping, and move in the direction of arrow a as a whole due to the difference in drive time. The type of movement is determined according to a given friction condition.

By continuously applying the drive pulse having the above waveform to the piezoelectric element 12a, the focus cam ring 13 can be continuously moved in the direction indicated by the arrow a.

When the focus cam ring 13 is moved in the direction opposite to the arrow a, it can be achieved by applying to the piezoelectric element 12a a drive pulse having a waveform having a rapid rising portion and a gradual falling portion following the rising portion. .

When the focus cam ring 13 moves, the magnetoresistive element 21 of the MR sensor attached to the focus cam ring 13 is magnetized at predetermined intervals in the magnetizing rod 22 provided in the fixed inner cylinder 3. Detecting magnetic poles. The detection signal is processed by the MR sensor output amplification unit 52, further compared with the intermediate level of the detection signal by the pulse signal conversion unit 53, converted into a pulse signal, and input to the control unit 51. Also,
The detection signal is converted into a digital value by the A / D converter 54 and input to the controller 51. The control unit 51 performs interpolation calculation based on the digital value of the detection signal, and determines a distance equal to or less than the magnetic pole interval. As a result, the position of the focus lens ring 13 is accurately detected.

When the focus detection circuit 62 on the camera side detects the in-focus state, the signal is input to the control section 51, and the control section 51 instructs the piezoelectric actuator drive section 57 to stop the output of the drive pulse. , The focus ring 13 stops moving.

Next, a manual focus, that is, an AF / MF switching switch 6 installed on the camera side (not shown)
Control when 1 is switched to the MF side will be described.

When the manual focus ring 14 is operated, the operating states are the encoder pattern 14a and the brush 14.
It is detected as a pulse signal by the manual focus ring detector 56 composed of b. The pulse signal is discriminated by the pulse signal discriminating circuit 55, and a signal (CW) indicating the operation direction of the manual focus ring 14 and a signal (INT) indicating the operation amount are output. Based on these signals, the control unit 51 causes the piezoelectric actuator drive unit 57 to drive a waveform having a gradual rising portion and a subsequent rapid falling portion, as in the case of the autofocus. The piezoelectric actuator is driven by instructing the output of a pulse or a drive pulse having a waveform having a rapid rising portion and a gentle falling portion following the rising portion. [Structure of Reflective Telephoto Lens Device]
An autofocus type reflective telephoto lens device using a mechanical conversion element will be described.

FIG. 14 is a transverse sectional view taken along the optical axis of the reflective telephoto lens device according to the second embodiment of the present invention.
Reference numeral 1 is a fixed barrel, 72 is a first lens, and 73 is a first lens holding frame which holds the first lens and which is fixed to the fixed barrel 71.
Reference numeral 74 denotes a main mirror, which has a main mirror reflection surface 74a (constituting a concave mirror) that reflects subject light incident through the first lens 73. Reference numeral 75 denotes a main mirror holding frame that holds the main mirror 74, and its rearward extension is fixed to the fixed barrel 71 and also to the lens mount 76.

Reference numeral 81 denotes a secondary mirror, which has a secondary mirror reflecting surface 81a (constituting a convex mirror) that reflects the subject light reflected from the primary mirror 74, and is held by the secondary mirror holding frame 84. The secondary mirror holding frame 84 is driven by a piezoelectric type actuator to be described later to perform focusing (focusing operation).

Reference numeral 77 is a second lens, 78 is a third lens arranged on the image plane side, 95 is a drive circuit for driving the piezoelectric element 82a, and 96 is an electrical wiring between the piezoelectric element 82a and the drive circuit 95. Indicates.

Reference numeral 82 is a piezoelectric actuator for moving the sub-mirror holding frame 84, and its structure and operation are similar to those described in FIGS. 1 and 2. In FIG. 14, reference numeral 82a is a piezoelectric element, 82b is a drive shaft, 82c is a frame, and 83a is a moving member. The sub-mirror holding frame 84 is fixed to the moving member 83a by appropriate means (not shown). The frame 82c is fixed to a supporting member 79 provided behind the first lens 72 by appropriate means. The details of the structure of the piezoelectric actuator will be described later.

FIG. 15 is a cross sectional view along the optical axis of the reflective telephoto lens device according to the third embodiment of the present invention.
The difference from the second embodiment is that the direction of the piezoelectric actuator 82 for moving the secondary mirror 81 is opposite to that of the second embodiment.
The piezoelectric element 82a side is arranged on the first lens 72 side. Since the structure of the piezoelectric actuator 82 and the structure of the lens barrel are the same as those of the second embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 16 is a transverse sectional view along the optical axis of the reflective telephoto lens device according to the fourth embodiment of the present invention.
The difference from the embodiment is that the central portion of the first lens 72 is hollowed out, and the secondary mirror 81 and the piezoelectric actuator 82 for moving the secondary mirror 81 are arranged in the central portion of the blanked first lens 72. It was done. Since the structure of the piezoelectric actuator 82 and the structure of the lens barrel are the same as those of the second embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 17 is a transverse sectional view taken along the optical axis of the reflective telephoto lens device according to the fifth embodiment of the present invention.
The difference from the embodiment is that the third lens 7 arranged on the image plane side
The holding frame 85 of No. 8 is driven by the piezoelectric actuator 82 to perform focusing (focusing operation). Piezoelectric actuator 82 frame 82c
Are fixed to the main mirror holding frame 75. The secondary mirror 81 is the first
It is fixed to a support member 79 provided behind the lens 72.
Since the structure of the piezoelectric actuator 82 and the structure of the lens barrel other than the above are the same as those of the second embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 18 is a transverse sectional view along the optical axis of the reflective telephoto lens device according to the sixth embodiment of the present invention.
The difference from the embodiment is that the first lens 72 on the subject side and the secondary mirror 81 fixed to the support member 79 provided behind the first lens 72 are driven by a piezoelectric actuator 82 for focusing. This is configured to perform (focusing operation).

Frame 82 of piezoelectric type actuator 82
c is fixed to an extension 75a of the main mirror holding frame 75 along the optical axis direction, and the holding frame 73 of the first lens 72 is fixed to an extension of a moving member 83a of the piezoelectric actuator 82. Since the structure of the piezoelectric actuator 82 and the structure of the lens barrel other than the above are the same as those of the second embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted.

Details of the structure of the piezoelectric actuator suitable for the reflective telephoto lens devices of the second to sixth embodiments will be described below.
This will be described with reference to FIGS. 19 and 20 to 22.

FIG. 19 is a perspective view of the piezoelectric actuator 82 in a disassembled state. In FIG. 19, the frame 8
2c is provided with support members 82f, 82g, 82h,
The drive shaft 82b is supported by support members 82f and 82g so as to be movable in the axial direction. One end of the piezoelectric element 82a is adhesively fixed to the end of the drive shaft 82b via a member 82d,
The other end of the piezoelectric element 82a is adhesively fixed to the member 82e,
The member 82e is fixed to the support member 82h with machine screws 82j.

The moving member 83a has right and left rising portions 83g.
And a contact portion 83h having a groove having a semicircular cross section at the center, the drive shaft 82b penetrates the rising portion 83g, and the lower half of the drive shaft 82b contacts the groove having a semicircular cross section in the contact portion 83h. . A pad 83b is arranged above the contact portion 83h and contacts the upper half of the drive shaft 82b.
An elastic member 83c fixed to the moving member 83a with a machine screw 83d is arranged on the pad 83b.
The pad 83b is pressed against the drive shaft 82b by the urging force of
An appropriate frictional force is generated between the drive shaft 82b and the moving member 83a and the pad 83b to bring them into contact with each other.

The above-described second embodiment shown in FIG. 14 and FIG.
In the case of the third embodiment shown in FIG. 6 and the fourth embodiment shown in FIG.
A small screw 8 for fixing the elastic member 83c to the moving member 83a.
3d, and other suitable means (not shown) for holding the auxiliary mirror 8
4 is fixed. Further, in the case of the fifth embodiment shown in FIG. 17, a small screw 83d for fixing the elastic member 83c to the moving member 83a, and other appropriate means not shown in the figure, the third member is used.
The lens holding frame 85 is fixed.

On the back surface of the moving member 83a, the magnetoresistive element 9 of the MR sensor for detecting the position of the moving member 83a.
1 is fixed, and the magnetizing rod 92 is fixed to the frame 82c of the actuator, and the position of the secondary mirror or the lens is detected by the MR sensor composed of the magnetoresistive element 91 and the magnetizing rod 92.

20 to 22 are perspective views showing the appearance of the assembled state of the actuator shown in FIG. 19 in which the shape of the supporting member 82f on the frame 82c is slightly deformed. There is.

In FIG. 20, the supporting member 82f on the frame 82c is a rectangular parallelepiped block. This actuator is an actuator suitable for the second embodiment shown in FIG. 14, and a supporting member 82f has an outer end surface having a large area suitable for fixing to a supporting member 79 provided behind the first lens 72. Have. This actuator is also an actuator suitable for the fifth embodiment shown in FIG. 17 and the sixth embodiment shown in FIG.

The one shown in FIG. 21 differs from that shown in FIG. 20 in that the outer end face of the support member 82f is formed in a stepped shape. This actuator, like the third embodiment shown in FIG. 15 and the fourth embodiment shown in FIG. 16, when the support member 82f of the actuator 82 is arranged on the side of the primary mirror 74, The range in which the light beam reflected by the main mirror 74 and incident on the sub mirror 81 is blocked (kicked) can be reduced.

22 is different from that shown in FIG. 20 in that the outer end surface of the supporting member 82f is formed in a substantially semicircular shape. This actuator has the same structure as the third embodiment shown in FIG. 15 and the fourth embodiment shown in FIG.
When the support member 82f of the switch 82 is arranged so as to be positioned on the side of the primary mirror 74, the range in which the light flux reflected by the primary mirror 74 and incident on the secondary mirror 81 is blocked (kicked) can be reduced. .

The actuator shown in FIG. 21 and FIG.
In this embodiment, the outer end surface of the support member 82f is formed in a stepped shape or a substantially semicircular shape, but it may be formed in a stepped shape or a substantially semicircular shape on the support member 82h side. With this structure, as in the second embodiment shown in FIG. 14, when the supporting member 82h of the actuator 82 is arranged so as to be located on the side of the main mirror 74, it is reflected by the main mirror 74 and reflected by the sub mirror. Mirror 81
It is possible to reduce the range in which the light flux incident on is blocked (kicked).

Further, as shown in FIGS. 21 and 22, the support member 82f side on the frame 82c is formed in a stepped shape or a substantially semicircular shape, and in addition to the actuator arranged inside the lens barrel. The height of the support member 82f or the support member 82h located on the side of the main mirror 74 is gradually lowered toward the outside of the frame 82c, or the height of the support member 82f or the support member 82h is set as low as possible.
Moreover, by reducing the area, it is possible to reduce the range in which the light flux reflected by the primary mirror 74 and incident on the secondary mirror 81 is blocked (kicked).

The second embodiment shown in FIG. 14 through FIG.
In the fourth embodiment shown in FIG. 23, the actuator 82 has an actuator 82 on the outer side FX of a frame (field frame) FM indicating the passage range of the light flux in the lens corresponding to the photographing field of view of the camera as shown in FIG. By arranging so as to be positioned, the light flux reflected by the main mirror 74 and incident on the sub mirror 81 can be prevented from being blocked by the actuator 82.
At this time, since the space on the short side of the frame FM is larger than that on the long side, it is desirable to place the actuator 82 on the short side.

Next, the arrangement of the drive circuit for driving the actuator in the lens barrel and the arrangement of the electric wiring between the drive circuit and the piezoelectric element of the actuator will be described.

As shown in FIG. 25, in the conventional reflective telephoto lens device, the speed reduction mechanism 20 is provided in the portion near the lens mount portion.
7 were provided. Since the present invention does not require such a speed reducing mechanism, a drive circuit 95 for driving the actuator is arranged in the space where the speed reducing mechanism is removed.

Further, the electrical wiring between the drive circuit and the piezoelectric element of the actuator is the same as that shown in FIG. 25 in the second embodiment shown in FIG. 14 to the fourth embodiment shown in FIG. The actuator 82 is arranged so as to be positioned outside the frame FM that indicates the passage range of the light flux in the lens corresponding to the field of view (field frame) FM. Therefore, the electric wiring between the drive circuit 95 and the piezoelectric element 82a. 96 also connects to the drive circuit 95 via the outer surface of the frame and the inner surface of the fixed cylinder 71.

The electric wiring 96 is formed of a flexible printed board on which a transparent electric wire is printed on a flexible transparent film, the surface of which is subjected to antireflection treatment, or a flexible printed board in which the electric wire is printed. It is formed of a substrate, and its surface is subjected to black antireflection treatment.

The electric wiring 96 is arranged so that the film surface on which the electric wiring is formed is parallel to the light flux when the electric wiring 96 is located at a position where it crosses the light flux in the lens device. Minimize the blocked light flux.

The control circuit for focusing the lens on the subject and the control operation are the same as the control circuit and the control operation thereof according to the first embodiment described above with reference to FIG. However, the focus ring 13 in FIG.
Are the sub-mirror holding frames 84 and 5 of the second to fourth embodiments.
Since it corresponds to the holding frame 85 of the third lens 78 of the embodiment and the holding frame 73 of the first lens 72 of the sixth embodiment,
It should be understood as such.

[0093]

As described above, the lens apparatus of the present invention is an actuator for driving a lens that contributes to focusing among the lenses composed of a plurality of lens groups.
An electro-mechanical conversion element, a driving member disposed along the optical axis direction, coupled to the electro-mechanical conversion element and displaced together with the electro-mechanical conversion element, and a lens group that contributes to the focusing. The electric wiring formed on the film surface connecting the actuator and the driving circuit for driving the actuator is composed of a moving member which is coupled to the supporting frame of the above and frictionally coupled to the driving member. When it is in a position where it crosses the light flux in the lens device, the film surface on which the electrical wiring is formed is arranged so as to be parallel to the light flux.

As a result, the range of the light beam blocked by the electric wiring can be suppressed to a minimum, and the rotational movement of the helicoid ring or the like is converted into the movement in the optical axis direction by the helicoid screw like the conventional lens. It is possible to obtain the effects that the driving mechanism of the lens group can be simply put together, the number of parts can be reduced, and the weight can be reduced without using a complicated configuration such as.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of a zoom lens device according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a drive mechanism portion of the lens device shown in FIG.

FIG. 3 is a diagram showing an example of a waveform of a drive pulse applied to a piezoelectric actuator.

FIG. 4 is a diagram for explaining a movement locus of lens groups forming the zoom lens device.

FIG. 5 is a diagram illustrating a relationship among a focal length, a subject distance, and a moving amount set in a second lens group.

FIG. 6 is a diagram illustrating a relationship between a focus cam and a zoom cam of the second lens group.

FIG. 7: Ferromagnetic thin film magnetoresistive element type position sensor (MR
Explanatory drawing of (sensor).

FIG. 8 is a diagram for explaining a magnetic pole interval of a magnetizing rod that constitutes the MR sensor, a specific arrangement of magnetoresistive elements, and an output signal thereof.

FIG. 9 is a diagram illustrating an output signal processing circuit of an MR sensor.

FIG. 10 is a development view of the encoder pattern provided on the many-hour focus ring.

FIG. 11 is a discrimination circuit diagram for discriminating the encoder output of the manual focus ring.

FIG. 12 is a diagram for explaining output waveforms of the discrimination circuit shown in FIG. 9.

FIG. 13 is a block diagram of a control circuit of the lens device.

FIG. 14 is a cross-sectional view showing the structure of a reflective telephoto lens device according to a second embodiment.

FIG. 15 is a sectional view showing the configuration of a reflective telephoto lens device according to Example 3.

FIG. 16 is a sectional view showing the arrangement of a reflective telephoto lens device according to Example 4.

FIG. 17 is a sectional view showing the structure of a reflective telephoto lens device according to Example 5.

FIG. 18 is a sectional view showing the arrangement of a reflective telephoto lens device according to Example 6;

FIG. 19 is a perspective view of a piezoelectric actuator suitable for the second to sixth embodiments in a disassembled state.

20 is a perspective view of the piezoelectric actuator shown in FIG. 19 in an assembled state.

FIG. 21 is a perspective view of a modification of the piezoelectric actuator shown in FIG.

22 is a perspective view of another modification of the piezoelectric actuator shown in FIG.

FIG. 23 is a diagram illustrating a light flux passage range in a lens corresponding to a field of view of a camera.

FIG. 24 is a cross-sectional view showing a configuration of a conventional zoom lens device.

FIG. 25 is a cross-sectional view showing the configuration of a conventional reflective telephoto lens device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 lens outer cylinder 2 zoom operation ring 3 fixed inner cylinder 4 zoom cam ring 5 1st lens group holding frame 6 2nd lens group holding frame 7 3rd lens group holding frame 8 4th lens group holding frame 9 z- Mucam ring 12,82 Piezoelectric actuator 12a, 82a Piezoelectric element 12b, 82b Drive shaft 13a, 83a Contact portion 82c Frame 13 Focus-cam ring 14 Manual focus-ring L1 First lens L2 Second lens L3 Third Lens L4 Fourth lens 71 Fixed cylinder 72 First lens 74 Primary mirror 76 Lens mount section 77 Second lens 78 Third lens 81 Secondary mirror

Claims (3)

[Claims] 1. A lens apparatus for performing focusing operation by moving a lens, which is composed of a plurality of lens groups, that contributes to focusing by moving in the optical axis direction by an actuator arranged in a lens barrel. An electro-mechanical conversion element, a drive member arranged along the optical axis direction and coupled to the electro-mechanical conversion element to be displaced together with the electro-mechanical conversion element, and support for a lens group that contributes to the focusing. An actuator composed of a moving member having a frame coupled thereto and frictionally coupled to the driving member, a drive circuit for driving an electromechanical conversion element of the actuator, and an electromechanical conversion of the actuator. An electric wire is formed on a film surface for connecting the element and the driving circuit, and the electric wire is located at a position where the electric wire crosses the light flux in the lens device. When the lens apparatus characterized by film surface formed of the electric wires are arranged parallel to the light beam. 2. The electric wiring formed on a film surface connecting the electro-mechanical conversion element and the driving circuit is an electric wiring formed by printing on a flexible transparent film. The lens device according to claim 1. 3. The electric wiring formed on a film surface for connecting the electro-mechanical conversion element and the drive circuit is formed by printing on a flexible film, and the surface thereof is subjected to an antireflection treatment. The lens device according to claim 1, which is a wiring.