JPH09269446A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make strength of a cam member forming a cam groove sufficient and to reduce a driving load of the cam member when a focus is switched. SOLUTION: This device is constituted of a first guide part guiding second lens units 3, 4 so as to plot a prescribed locus in an optical path for first lens units 1, 2 by first, second cam grooves 6a, 6b, 5a, 5b and engagement members 2a, 4a and performing focal distance switching and a second guide part guiding the second lens units so as to plot the prescribed locus different from the locus by the first guide part in the optical path for the first lens units and performing focus adjusting and alternately provided for the first guide part. Then, the first cam groove 6a is so as to slope in the same direction for the optical axial direction within the all range of the first guide part and the second guide part, and the second cam groove 6b made is the direction parallel to the optical axis without sloping within the range of the second guide part, and is formed so s to slope in the direction opposite to the first cam groove 6b for the optical axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first guide unit for guiding a second lens unit so as to draw a predetermined locus in an optical path with respect to the first lens unit and switching a focal length, and The first lens guide unit guides the second lens unit so as to draw a predetermined trajectory different from the trajectory of the first guide unit in the optical path with respect to the first lens unit. The present invention relates to an improvement of a lens device included in an optical device such as a camera having second guide portions alternately provided.

[0002]

2. Description of the Prior Art
No. 7 proposes a camera equipped with a two-unit zoom lens composed of two lens groups and capable of selecting a zoom position and adjusting a focus by rotating a zoom ring.

FIG. 8 is a diagram showing an outline of a main part thereof, and FIG. 9 is an enlarged view showing a movement locus of each lens group.

In FIG. 8, 101 is a convex lens unit, 102 is a shutter blade that also serves as an aperture, 103 is a concave lens unit, and 104 is an image-taking surface. The upper part of FIG. 8 shows a lens in a short focal length (hereinafter referred to as WIDE) state. The state where the lens is in focus is shown, and the lower side of the figure shows the state where the lens is closest to the lens in the long focal length (hereinafter referred to as TELE) state.

Further, arrows C and M shown in the middle of them
1 to M4 and N1 to N3 (see also FIG. 9) are the lens units 1 for the respective rotation angles of the zoom ring shown on the right side.
Each position of 01 and 103 on the optical axis is shown. That is, arrows C, M1 to M4, and N1 to N3 indicate the movement process (trajectory) of each lens group when the horizontal axis represents the amount of lens movement and the vertical axis represents the rotation angle of the zoom ring.

When the lens focus is set to ∞ at the zoom position of WIDE in FIGS. 8 and 9, the zoom ring is moved to 3
When rotated by 0 °, the convex lens unit 101, the shutter 102, and the concave lens unit 103 move as shown in the figure. For this reason, the magnification of the photographing lens system does not change during the arrow M1, and the focus is adjusted in the WIDE state by the rotation of the zoom ring. .

When the photographer wants to increase the magnification a little and switches to the normal state, the zoom ring is set to 120
It stops at the position based on the distance measurement information between ° and 150 °.

That is, as is already clear, when the rotation of the zoom ring comes to a position of 120 °, the normal state (TE
In the state of the intermediate magnification between LE and WIDE), the lens position is focused on ∞. If the zoom ring is further rotated from this state, the subsequent 30
During °, the lens system is in the normal state and only focus adjustment is performed. Similarly, when using TELE, set the zoom ring to 18
When rotated by 0 °, the lens focus comes to ∞ with TELE, and when the zoom ring is further rotated, TEL
The lens position is such that the lens is in focus at a short distance in the E state.

With such a structure, the magnification and the focus can be adjusted only by rotating a single zoom ring.

Usually, in this type of camera, the convex lens unit 101 and the concave lens unit 103 are engaged with a key groove, which is fixed to a camera body (not shown) and is parallel to the optical axis, and locked to rotate about the optical axis. The zoom ring is engaged with a cam groove formed in the zoom ring, and the zoom ring is rotated to move to the lens position in the direction parallel to the optical axis.

[0011]

However, in the above-mentioned conventional example, the length of the cam groove formed in the zoom ring becomes long as shown in FIGS. 8 and 9. 240 in this example
It has a length of °. When the area occupied by the cam groove on the circumference becomes large, the strength of the member in which the cam groove is formed, that is, the zoom ring, becomes weak. Further, since the amount of movement of the lens in the focus switching area is large, the drive load of the zoom ring becomes large.

(Object of the Invention) The object of the present invention is to make the strength of the cam member in which the cam groove is formed sufficient, and
It is an object of the present invention to provide a lens device that can reduce the drive load of a cam member when switching the focus.

[0013]

In order to achieve the above object, the present invention according to claims 1 to 3 provides a first lens unit integrally having an engaging member and an engaging member integrally. A second lens unit having the first cam member, a first cam member having a first cam groove with which the engaging members engage, and a second cam member fixed to the device with which the engaging members engage. A lens device comprising a second cam member having a cam groove, wherein the first and second cam grooves and the respective engaging members cause a predetermined locus with respect to the first lens unit in an optical path. A first guide portion for guiding the second lens unit to switch the focal length, and a predetermined trajectory different from the locus of the first guide portion in the optical path with respect to the first lens unit. Guide the second lens unit to draw a locus and adjust the focus. , A second guide portion that is alternately provided with respect to the first guide portion, and the first cam groove is formed in the entire range of the first guide portion and the second guide portion, The second cam groove is formed so as to be inclined in the same direction with respect to the optical axis direction, and the second cam groove is parallel to the optical axis direction without inclination in the range of the second guide portion. In the range of the guide portion, it is formed so as to be inclined in the direction opposite to the first cam groove with respect to the optical axis direction.

With the above structure, the second cam groove formed in the second cam member, which is the fixing member, has a circumferential length, for example, of the first cam groove formed in the first cam member. It is possible to suppress the increase of the length of the first cam member and to increase the rotation amount of the first cam member (compared with the conventional one) when the focus is switched for the same length.

In order to achieve the above object as well, the present invention according to claims 4 to 6 is characterized in that a first engaging member is integrally provided.
A lens unit, a second lens unit integrally having an engaging member, a third cam member having a third cam groove with which each engaging member engages, and fixed to the device,
A fourth cam member having a fourth cam groove with which each of the engaging members engages, the lens device comprising: the first and the third cam grooves and the engaging member; The first lens unit for guiding the second lens unit to switch the focal length so as to draw a predetermined locus in the optical path with respect to the second lens unit, and the first lens unit in the optical path for the first lens unit. And second guide portions which are alternately provided with respect to the first guide portion and which guides the second lens unit to perform focus adjustment so as to draw a predetermined trajectory different from the trajectory of the first guide portion. The fourth cam groove is formed so as to be inclined in the same direction with respect to the optical axis direction in the entire range of the first guide portion and the second guide portion, and the third cam groove is formed. In the range of the second guide portion, there is no inclination and A direction, in the range of the first guide portion, with respect to the optical axis direction so as to form inclined in a direction opposite to the said fourth cam groove.

With the above structure, the third cam groove formed in the third cam member, which is, for example, the rotating member, is the same as the fourth cam groove formed in the fourth cam member, which is, for example, the fixed member. This makes it possible to prevent the length on the circumference from increasing and to increase the rotation amount of the fourth cam member (compared to the conventional one) when performing focus switching of the same length.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments.

1 to 6 are views according to a first embodiment of the present invention. First, the cross section of the lens barrel of the camera and the main circuit configuration will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a first convex lens.
The lens group, 2 is a first lens holder for holding the first lens group 1, 3 is a second lens group composed of concave lenses, 4 is a second lens holder for holding the second lens group 3, and The first lens group 1 and the second lens group 3 constitute a photographic lens having a known zoom function.

Reference numeral 5 denotes a straight groove cylinder fixed to a camera body (not shown), and has a groove 5a into which the pin 2a of the first lens holder 2 and the pin 4a of the second lens holder 4 are slidably fitted. 5b is formed, and the action of the groove 5a guides the first lens holder 2 and the second lens holder 4, that is, the first lens group 1 and the second lens group 3 in the optical axis direction. . Reference numeral 6 denotes a cam barrel attached to a camera body (not shown) so as to be rotatable about the optical axis of the taking lens, and a first cam groove 6a slidably fitted to the pin 2a of the first lens holder 2; A second cam groove 6b slidably fitted to the pin 4a of the second lens holder 4 is formed.

Reference numeral 7 is a first drive gear whose shaft portions 7a and 7b are rotatably held by a camera body (not shown), and a small gear portion 7c is a gear portion 6 formed on the outer peripheral portion of the cam barrel 6.
It meshes with c and rotates the cam barrel 6 around the optical axis. Reference numeral 8 denotes a known step motor, the output shaft of which is connected to the drive gear 7 (via the small gear portion 7c) to rotate the drive gear 7. Reference numeral 9 denotes a cam position detecting means for detecting the rotational position of the cam cylinder 6, which is composed of, for example, a potentiometer or the like. If the potentiometer is used as the cam position detecting means in this way, a resistance value corresponding to the rotational position of the cam cylinder 6 is obtained. Can be output. That is, by detecting this resistance value, the positions of the first lens group 1 and the second lens group 3 can be known.

Reference numeral 10 is a motor drive circuit for driving the step motor 8, and 11 is a control circuit including a microcomputer or the like for controlling the entire sequence. Reference numeral 12 denotes an exposure control unit including a known shutter mechanism and an exposure control circuit, 1
Reference numeral 3 is a known distance measuring means for measuring the distance to the subject. Reference numeral 14 denotes a zoom switch for selecting the focal length of the photographing lens, which may be a known one and is composed of, for example, a potentiometer. Depending on the resistance value output from the zoom switch 14 composed of a potentiometer,
The control circuit 10 drives the step motor 8 to rotate the cam barrel 6 to a desired position. A release switch 15 is used to release the camera by closing it.

FIG. 2 is a perspective view of the cam barrel 6 shown in FIG.

Next, the first cam groove 6 formed in the cam barrel 6
The a and the second cam groove 6b will be described with reference to FIG.

FIG. 3 shows the first cam groove 6a of the cam barrel 6 and the second cam groove 6a.
It is a development view of a cam groove 6b.

The first cam groove 6a and the second cam groove 6 of the cam barrel 6
When the first lens group 1 and the second lens group 3 are engaged at the 0 ° position of b, the taking lens composed of the first lens group 1 and the second lens group 3 is at the zoom position of WIDE, and , Is in focus at infinity.

The first cam groove 6a and the second cam groove 6 of the cam barrel 6
In the range of 0 ° to 30 ° of b, the first lens group 1, the second lens group
While the lens group 3 is engaged, that is, in the range A1, the magnification of the taking lens does not change, the focus is changed in the WIDE state, and the lens is focused at the position of 30 ° to the closest distance. Become. In other words, due to the rotation of the cam barrel 6,
The first lens group 1 and the second lens group 3 respectively move in the range of a1 and a5 in the direction parallel to the optical axis, and the focusing operation is performed.

The first cam groove 6a and the second cam groove 6 of the cam barrel 6
When the first lens group 1 and the second lens group 3 are engaged at the 60 ° position of b, the taking lens composed of the first lens group 1 and the second lens group 3 has a focus slightly longer than the WIDE position. The zoom position is at a distance, and the focus is infinite. That is, only the focal length is changed within the range of B1.

The first cam groove 6a and the second cam groove 6 of the cam barrel 6
While the first lens group 1 and the second lens group 3 are engaged in the range of 60 ° to 90 ° of b, that is, the range of A2 is
Similar to the range of A1 above, the magnification of the taking lens does not change, the focus is changed with its focal length, and the lens is in focus at the position of 90 ° to the closest distance. That is, the rotation of the cam barrel 6 causes the first lens group 1 and the second lens group 3 to move within the range of a2 and a6 in the direction parallel to the optical axis, and the focusing operation is performed.

Similar to B1, the first cam groove 6 of the cam barrel 6
a, when the first lens group 1 and the second lens group 3 are engaged at the 120 ° position of the second cam groove 6b, the zoom position of the photographing lens is further changed to the long focus side and The focus is on the distance.

The first cam groove 6a and the second cam groove 6 of the cam barrel 6
When the first lens group 1 and the second lens group 3 are engaged in the range of 120 ° to 150 ° of b, that is, the range of A3 in the figure, the magnification of the taking lens does not change as in the range of A1. , The first lens group 1 and the second lens group 3 in the direction parallel to the optical axis.
Moves in the range of a3 and a7, and the focus is changed while keeping the focal length, and at the position of 150 °, the lens is in focus at the shortest distance.

Further, when the first lens group 1 and the second lens group 3 are engaged at the 180 ° positions of the first cam groove 6a and the second cam groove 6b of the cam barrel 6, the zoom is the most TELE. The focal length of the taking lens is changed to the position, and the focus is on an infinite distance.

The first cam groove 6a of the cam barrel 6 and the second cam groove 6a
While the first lens group 1 and the second lens group 3 are engaged in the range of 180 ° to 210 ° of the cam groove 6b, that is, the range A4 in the figure, the magnification of the taking lens is the same as the range A1. Does not change, the focus is changed with the focal length, and 2
At the position of 10 °, the lens focus is in the closest range. In this range, the first lens group 1 and the second lens group 3 move in the range of a4 and a8 in the direction parallel to the optical axis.

As described above, the first cam groove 6a and the second cam groove 6b formed in the cam barrel 6 cause the photographing lens composed of the first lens group 1 and the second lens group 3 to perform the focusing operation. The cam regions A1, A2, A3, A4 and the cam regions B1, B2, B3 for changing the focal length are formed alternately and continuously.

FIG. 4 is a perspective view of the rectilinear groove cylinder 5 shown in FIG.

FIG. 5 shows the groove 5 formed in the straight-groove cylinder 5.
FIG. 5A is a development view of a groove 5b.

The pin 2a of the above-mentioned first lens holder 2
Is slidably fitted in the groove 5a of the straight-moving groove cylinder 5 and slidably fitted in the first cam groove 6a of the cam cylinder 6,
Is rotated to move in the direction parallel to the optical axis. Similarly, the pin 4a of the second lens holder 4 is slidably fitted in the groove 5b of the rectilinear groove cylinder 5 and slidably fitted in the second cam groove 6b of the cam cylinder 6, and the cam cylinder 6 Is rotated to move in the direction parallel to the optical axis direction.

As shown in FIG. 5, the grooves 5a and 5b of the rectilinear groove cylinder 5 are in the ranges a1, a2, a3 and a4 where the first lens group 1 and the second lens group 3 shown in FIG. 3 focus. ,as well as,
In the range of a5, a6, a7, a8, linear grooves are formed parallel to the optical axis.

Further, as shown in FIG. 4, the groove 5 of the straight-moving groove cylinder 5 is
The portions a1, a2, a3, a4 parallel to the optical axes of a and 5b.
In a5, a6, a7, and a8, a2 is connected by a groove inclined by θ1 with respect to a1, a3 is connected by a groove inclined by θ1 with respect to a2, and a4 is a groove inclined by θ1 with respect to a3. They are connected, a6 is connected by a groove inclined by θ2 with respect to a5, a7 is connected by a groove inclined by θ2 with respect to a6, and a8 is connected by a groove inclined by θ2 with respect to a7.

These grooves 5a and 5b are opposite to the first cam groove 6a and the second cam groove 6b of the cam barrel 6 shown in FIG. It is formed so that it has a shape-like inclination.

In the present embodiment, as shown in FIG. 5, the portions a1, a2, which are parallel to the optical axis of the grooves 5a, 5b of the rectilinear groove tube 5.
In the parts a3, a4, a5, a6, a7, a8, a2 is at a position rotated by 20 ° with respect to a1, a3 is at a position rotated by 20 ° with respect to a2, and a4 is at 20 ° with respect to a3.
In a rotated position, a6 is in a position rotated by 20 ° with respect to a5, a7 is in a position rotated by 20 ° with respect to a6, and a8 is in a position rotated by 20 ° with respect to a7.

According to the above construction, during the focusing operation, the cam barrel 6 and the portions of the grooves 5a and 5b of the rectilinear groove barrel 5 parallel to the optical axis.
The pin 2a of the first lens holder 2 and the pin 4a of the second lens holder 4 are engaged with and driven by the first cam groove 6a and the second cam groove 6b, but the grooves 5a and 5b of the rectilinear groove cylinder 5 are Since only the cam barrel 6 is linear and the groove is cam-shaped, the dimensional accuracy of the parts can be relatively high.
Positioning of the first lens group 1 and the second lens group 3 during the focusing operation can be performed with the same precision as in the past.

When switching the focal length, the cam barrel 6 is set to "30".
Rotation of “+ 20 °” switches to the next zoom position. This is because, as described above, the grooves 5a and 5b are formed so as to be inclined with respect to the first cam groove 6a and the second cam groove 6b of the cam barrel 6 in the direction opposite to the optical axis direction. Is. Therefore, if the grooves 5a and 5b of the rectilinear groove cylinder 5 have a rectilinear groove parallel to the optical axis over the entire range, the cam cylinder 6 can be switched to the adjacent zoom position by rotating 30 °. On the other hand, in the present embodiment, further 2
It is necessary to rotate the cam barrel 6 0 ° extra (cam barrel 6
The rotation amount of will increase compared to the conventional one),
The drive load on the cam barrel 6 can be reduced by that amount, and the drive load on the cam barrel 6 can be reduced even when the amount of movement of the lens when switching the focal length is large.

Since the driving load on the cam barrel 6 can be reduced, the first cam groove 6a and the second cam groove 6 of the cam barrel 6 can be reduced.
Even if the cam angle in the range of B1, B2, B3 of b is made steep and the range of B1, B2, B3 is made small to shorten the length of the cam groove on the circumference, the cam cylinder 6 is driven. Is possible. In this way, the length of the cam groove on the circumference should be shortened (conventionally, the length was 240 ° as shown in FIG. 8, but in the present embodiment, it is 210 ° as shown in FIG. The length of the cam cylinder 6 can increase the strength of the cam cylinder 6. Similarly, even if the focal length switching points are increased, B1 and B of the first cam groove 6a and the second cam groove 6b
Set the cam angle in the range of 2, B3 to a steep angle, and set B1,
By reducing the range of B2 and B3, the length of the cam groove on the circumference can be shortened, and the strength of the cam barrel 6 can be prevented from decreasing.

When switching the focal length, the first cam groove 6a, the second cam groove 6b of the cam barrel 6 and the groove 5a of the straight-moving groove barrel 5,
Since the lens position is determined by combining the two cam-shaped grooves with the cam-shaped groove portion of 5b, the lens position may be worse than the conventional one in terms of component accuracy, but the focal length switching No photographing is actually performed in time, that is, in the range of B1, B2, and B3, so that there is no actual damage.

Further, the first lens group 1 and the second lens group 3 rotate about the optical axis by switching the focal lengths. In the present embodiment, the straight groove 2 has two grooves 5a and 5b along the groove.
Rotate by 0 °. At this time, the first lens group 1 and the second lens group 2
The rotation amounts of the lens groups 3 at that time are the same. According to this, the first lens group 1 and the second lens group 3
Since the relative rotational positional relationship with and does not change, and the relationship such as eccentricity does not change, optical performance is maintained.

Next, the focusing operation of the camera having the above configuration and the operation at the time of switching the focal length will be described with reference to the flowchart shown in FIG.

In step # 1, the set value of the zoom switch 14, that is, the resistance value of the zoom switch 14 including a potentiometer is detected, and which zoom position should be set is detected from the input value. Then, in the next step # 2, the value of the cam position detecting means 9 which is also a potentiometer is detected to detect the current position of the cam barrel 6, that is, the zoom position of the photographing lens.

In the next step # 3, the set value of the zoom position detected in the above step # 1 and the above step # 3.
It is determined whether or not the zoom position currently configured by the taking lens detected in 2 is the same. If not, step # 4
To step motor 8 via motor drive circuit 10.
Drive. The driving direction of the step motor 8 is changed from the zoom position currently configured by the taking lens to the above step #
This is the direction toward the set zoom position detected in 1. Thereafter, the process returns to the previous step # 2, and the same operation is repeated.

In step # 3, the zoom position set value detected in step # 1 is the same as the zoom position currently formed by the taking lens detected in step # 2. Alternatively, when it is determined that they are the same by going through step # 4,
Go to step 5. Then, here, the driving of the step motor 8 is stopped via the motor drive circuit 10.

In the next step # 6, it is detected whether or not the release switch 15 is turned on. If it is not turned on, the process returns to step # 1 and the same operation as above is repeated. If it is ON, the process proceeds to step # 7, the distance measuring means 13 is driven to measure the distance to the subject, and the lens drive amount to the in-focus position is calculated. Then, in the next step # 8, the step motor 8 is driven via the motor drive circuit 10 based on the lens drive amount obtained in step # 7, and the cam barrel 6 is rotated to focus the photographing lens. Take action.

In the next step # 9, the value of the cam position detecting means 9 composed of a potentiometer is detected. Then, in the next step # 10, the above step # 7
It is determined whether or not the cam barrel 6 has come to a position corresponding to the lens driving amount calculated in step S6. If it has not come, that is, if the position of the photographing lens has not been adjusted in the focusing operation, the process returns to step # 8. , And the same operation is repeated.

After that, when it is determined that the photographing lens is positioned at the in-focus position, steps # 10 to #
Proceeding to 11, the rotation of the step motor 8 is stopped via the motor drive circuit 10. At this time, the step motor 8
The power supply to the coil (not shown) is not cut off, and the power supply to the coil is continued while the applied voltage of the micro step drive is held so that the rotor is held at that position. Then, in step # 12, the exposure control unit 14 is used to operate a shutter (not shown) to perform an exposure operation to a film (not shown). After this, the power supply to the step motor 8 may be cut off. Finally, in step # 13, normal camera operation, film advance by one frame, and the like are performed.

(Second Embodiment) FIG. 7 is a view showing a cross section and a main circuit configuration of a lens barrel of a camera according to a second embodiment of the present invention. The same reference numerals are given and the description thereof is omitted here.

In the first embodiment described above, the cam barrel 6 is driven by the step motor 8 to fix the rectilinear groove cylinder 5 to the camera body, and the cam cylinder 6 and the rectilinear groove cylinder 5 are rotated relative to each other to make the first movement.
The lens group 1 and the second lens group 3 were driven in a direction parallel to the optical axis.

In the second embodiment, the cam barrel 6 is fixed to the camera body, and the straight groove barrel 5 is driven by the step motor 8.

Similar to the first embodiment, the cam cylinder 6 is formed with the first cam groove 6a and the second cam groove 6b as shown in FIG. 3, and the straight groove cylinder 5 is also the first embodiment. Similar to the above embodiment, grooves 5a and 5b as shown in FIG. 5 are formed. A gear portion 5c is formed on the outer peripheral portion of the rectilinear groove cylinder 5, the gear portion 7c of the drive gear 7 is meshed with the gear portion 5c, and the step motor 8 is configured to rotate about the optical axis. The cam position detecting means 9 detects the rotational position of the rectilinear groove cylinder 5.

According to each of the above embodiments, the cam groove (6
It is possible to prevent the length occupied by a, 6b) on the circumference from becoming long, and it is possible to prevent the strength of the cam barrel 6 from decreasing.

Further, the driving load at the time of switching the focal length can be reduced, and the lens position accuracy at the time of focusing can be secured to be equal to that of the conventional one.

(Correspondence between Invention and Embodiment) In the first embodiment, the first lens group 1 and the first lens holder 2 are the same as the first lens unit described in claims 1 to 3.
The second lens group 3 and the second lens holder 4 are defined in claims 1 to 3.
The cam barrel 6 is provided in the second lens unit according to claim 3.
The straight advancing cylinder 5 is attached to the first cam member according to any one of claims 1 to 3.
Each corresponds to the second cam member described. Also, the first
The first cam groove 6a and the second cam groove 6b are the first cam groove according to claims 1 to 3, the grooves 5a and 5b are the second cam grooves according to claims 1 to 3, and the pins 2a and 4a are They correspond to the engaging members described in claims 1 to 3, respectively.

In addition, in the second embodiment, the first lens group 1 and the first lens holder 2 are defined in claims 4 to 6.
The 2nd lens group 3 and the 2nd lens holder 4 are the 2nd lens unit of Claims 4-6, and the rectilinear barrel 5 is the 3rd cam of Claims 4-6 in the described 1st lens unit. The cam barrel 6 corresponds to the member and corresponds to the fourth cam member according to claims 4 to 6, respectively. In addition, the first cam groove 6a and the second cam groove 6a
The cam groove 6b of claim 4 is the fourth cam groove of claims 4 to 6, the grooves 5a and 5b are the third cam grooves of claims 4 to 6, and the pins 2a and 4a are of claims 4 to 6. Each corresponds to an engaging member.

Further, the first cam groove 6a and the second cam groove 6b, the grooves 5a and 5b, and the pins 2a and 4a which form the range A1 to A4 shown in FIG. 3 for performing the focusing operation. Corresponds to the first guide portion of the present invention, and the portion forming the range B1 to B3 shown in FIG. 3 for switching the focal length corresponds to the second guide portion of the present invention.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims,
Needless to say, any configuration may be used as long as the functions of the embodiment can be achieved.

(Modification) In each of the above embodiments, the step motor is used as the drive source, but any motor may be used.

Although the present invention has been described as applied to a camera, it can be similarly applied to any optical device (for example, a photoprinting machine) capable of both focal length switching and focus adjustment. Is. It is also applicable as a single interchangeable lens.

Therefore, considering the application to the optical device other than the camera as described above, the first and third cam grooves (in the first embodiment, the first cam groove 6a and the first cam groove 6a) of the present invention are considered. The second cam groove 6b, in the second embodiment, the first and third cam members in which the grooves 5a, 5b) are formed (the cam barrel 6 in the first embodiment, and the second embodiment). The straight advancing cylinder 5) is not necessarily limited to the cylindrical shape.

Similarly, the second and fourth cam grooves of the present invention (the grooves 5a and 5b in the first embodiment, the first cam groove 6a and the second cam in the second embodiment). The second and fourth cam members (the straight advancing cylinder 5 in the first embodiment and the cam cylinder 6 in the second embodiment) in which the groove 6b) is formed are not necessarily limited to the cylindrical shape. Absent.

[0068]

As described above, according to the present invention,
It is possible to make the strength of the cam member sufficient and to reduce the driving load of the cam member at the time of changing the focal point.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross section and a main circuit configuration of a lens barrel of a camera according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a cam barrel shown in FIG.

FIG. 3 is a development view of a first cam groove 6a and a second cam groove 6b of the cam barrel shown in FIG.

FIG. 4 is a perspective view of the rectilinear groove cylinder shown in FIG. 1.

5 is a groove 5a and a groove 5 formed on the straight-grooved tube shown in FIG.
It is a development view of b.

FIG. 6 is a flowchart showing an operation of a main part of the camera of FIG. 1;

FIG. 7 is a diagram showing a cross section of a lens barrel of a camera and a main circuit configuration of a camera according to a second embodiment of the present invention.

FIG. 8 is a diagram for explaining a case where a zoom position is selected and a focus is adjusted by rotating a zoom ring in a camera including a conventional two-group zoom lens.

FIG. 9 is a diagram showing a part of FIG. 8 in an enlarged manner.

[Explanation of symbols]

 1 1st lens group 2 1st lens holder 2a pin 3 2nd lens group 4 2nd lens holder 4a pin 5 straight advance groove cylinder 5a, 5b groove 6 cam cylinder 6a 1st cam groove 6b 2nd cam groove

Claims (6)

[Claims] 1. A first lens unit integrally having an engaging member, a second lens unit integrally having an engaging member, and a first cam groove with which each engaging member engages. A lens device comprising: a first cam member having; and a second cam member fixed to the device, the second cam member having a second cam groove with which each of the engaging members engages. A first guide portion that guides the second lens unit so as to draw a predetermined locus in the optical path with respect to the first lens unit by the two cam grooves and each of the engaging members, and switches the focal length. The first lens unit is guided to the second lens unit so as to draw a predetermined locus in the optical path different from the locus of the first guide unit, and focus adjustment is performed. A second guide portion, which is provided alternately with respect to the guide portion, is configured, The first cam groove is formed to incline in the same direction with respect to the optical axis direction in the entire range of the first guide portion and the second guide portion, and the second cam groove is The second
In the range of the guide part, the direction is parallel to the optical axis direction without inclination, and in the range of the first guide part, in the direction opposite to the first cam groove with respect to the optical axis direction. A lens device, which is formed to be inclined. 2. The first cam member is a member rotatable about an optical axis of a lens, and the first cam groove covers the entire range of the first guide portion and the second guide portion. 2. The lens device according to claim 1, wherein the lens device is formed so as to be inclined in the same direction with respect to the optical axis direction. 3. The second cam member fixed to the device is a tubular member fitted to the first cam member, and the second cam groove is within the range of the second guide portion. Is a direction parallel to the optical axis direction without inclination, and is formed in the range of the first guide portion in a direction opposite to the first cam groove with respect to the optical axis direction. The lens device according to claim 2, wherein 4. A first lens unit integrally having an engaging member, a second lens unit integrally having an engaging member, and a third cam groove with which each of the engaging members engages. A lens device comprising: a third cam member having; and a fourth cam member fixed to the device, the fourth cam member having a fourth cam groove with which each of the engaging members engages. A first guide portion that guides the second lens unit so as to draw a predetermined locus in the optical path with respect to the first lens unit by the cam groove 4 and each of the engaging members and switches the focal length. The first lens unit is guided to the second lens unit so as to draw a predetermined locus in the optical path different from the locus of the first guide unit, and focus adjustment is performed. A second guide portion, which is provided alternately with respect to the guide portion, is configured, The fourth cam groove is formed so as to be inclined in the same direction with respect to the optical axis direction in all ranges of the first guide portion and the second guide portion, and the third cam groove is The second
In the range of the guide part, the direction is parallel to the optical axis direction without inclination, and in the range of the first guide part, the direction opposite to the fourth cam groove is in the optical axis direction. A lens device, which is formed to be inclined. 5. The third cam member is a member rotatable about an optical axis of a lens, and the third cam groove covers the entire range of the first guide portion and the second guide portion. The lens device according to claim 4, wherein the lens device is formed so as to be inclined in the same direction with respect to the optical axis direction. 6. The fourth cam member fixed to the device is a tubular member fitted to the third cam member, and the fourth cam groove is within the range of the second guide portion. Is a direction parallel to the optical axis direction without inclination, and is formed in the range of the first guide portion in a direction opposite to the third cam groove with respect to the optical axis direction. The lens device according to claim 5, wherein