JP2001228500A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the disengagement of the position of a zoom lens or focusing lens from a cam locus by the disengagement or the like of a screw threaded shaft and a rack by impulsive vibration. SOLUTION: The optical device having optical elements 21 and 22 movable on the basis of prescribed initial positions is provided with a vibration detecting means for detecting the vibration applied on a device body and a control means for resetting the optical elements to the initial positions when the vibration detected by the vibration detecting means exceeds a prescribed level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device having a movable optical element, such as a silver halide camera, a digital camera, a video camera and the like.

[0002]

2. Description of the Related Art A photographing optical system and an optical viewfinder of a camera are configured to drive some lenses in an optical axis direction for zooming and focusing. Then, as a drive mechanism for driving the lens, a screw is formed on the drive shaft of the stepping motor to form a screw screw shaft,
There is a case where a lens is driven by a meshing action of a screw screw shaft and a rack by engaging with a rack attached to a movable lens frame guided in the optical axis direction by a guide bar and rotating a stepping motor.

In this case, a memory such as a computer stores
The same cam locus is stored as when a zoom lens or focus lens (compensator lens) is driven by a cam barrel, and the computer is controlled so that the zoom lens and focus lens follow the cam locus during zoom operation. Move to zoom.

In addition, when the above-described driving mechanism is used, the screw screw shaft and the rack are disengaged from each other when receiving an impact vibration due to a drop or the like, and the moving lens group is allowed to move with respect to the screw screw shaft due to the vibration. In many cases, failure due to biting between the rack and the screw screw shaft at the time of impact does not occur.

[0005]

However, as described above, there is provided a driving mechanism having a structure in which a zoom operation is performed by engaging a screw screw shaft and a rack and a screw screw shaft and a rack are disengaged by impact vibration. In the case of using, when the meshing position of the screw screw shaft and the rack on the zoom lens or focus lens side shifts due to the impact, the position of the zoom lens or focus lens deviates from the cam locus, and the focus is shifted. There is a possibility that it will.

In the case where the optical viewfinder and the photographing optical system are independently operated for zooming, when the zoom lens is displaced by an impact, the relationship between the viewfinder and the photographing optical system is displaced, and the angle of view of the photographing optical system in the viewfinder. May not be obtained.

[0007] Similarly, the relationship between the zoom state of the photographing optical system and the irradiation angle of the zoom strobe deviates, and there is a possibility that proper strobe irradiation may not be performed on the subject.

[0008]

According to the present invention, there is provided an optical apparatus having an optical element which is movable with respect to a predetermined initial position, the vibration detecting the vibration applied to the apparatus body. A detecting means and a control means for returning the optical element to the initial position when the vibration detected by the vibration detecting means exceeds a predetermined level are provided.

In other words, when vibration exceeding a predetermined level (impact vibration, etc.) is applied to the main body of the apparatus, for example, the optical element may be displaced from a driving member for driving the optical element. By returning the optical element to the initial position and allowing the optical element to be driven with reference to the initial position thereafter, the influence on the optical system due to the above positional shift (field angle and focus shift in the photographing optical system, A shift of the zoom state from the photographing optical system and a shift of the irradiation angle of the zoom strobe from the zoom state of the photographing optical system are prevented.

When the present invention is applied to the photographing optical system, the optical viewfinder and the zoom strobe in the apparatus, a difference in the angle of view occurs between the photographing optical system and the optical viewfinder due to a large vibration. This makes it possible to reliably prevent the photographing operation from being performed differently from the photographer's intention, and prevent the strobe irradiation from reaching the entire photographing screen.

The position of the optical element before the vibration detected by the vibration detecting means exceeds a predetermined level is stored, and after the optical element is driven to return to the initial position,
If this optical element is driven to the stored position,
After a large vibration is applied, it is possible to immediately continue photographing or the like in the same state as before the vibration was applied.

[0012]

FIG. 2 shows an electric circuit configuration of a digital camera (optical device) according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a zoom lens driving motor for driving a zoom lens of a photographing optical system, and 12 denotes a zoom lens reset photo-interrupter for detecting switching when the zoom lens passes a zoom reset position.

Reference numeral 2 denotes a focus lens drive motor for driving a focus lens of the photographing optical system, and reference numeral 13 denotes a focus lens reset photo-interrupter for detecting switching when the focus lens passes a focus reset position.

Reference numeral 3 denotes an image sensor such as a CCD, and 4 denotes an image sensor 3
A signal processing circuit 6 for processing the signal from the controller 6; and a recording circuit 6 for recording the signal processed by the signal processing circuit 4. A microcomputer 5 controls the entire operation of the camera.

A finder drive motor for driving a seven-optical zoom finder, and a finder reset photointerrupter 14 for detecting switching when the zoom finder passes through a finder reset position.

Reference numeral 8 denotes a flash drive motor for changing the irradiation angle of the zoom flash, and reference numeral 15 denotes a flash reset photointerrupter for detecting switching when the zoom flash passes a flash reset position. In addition,
The microcomputer 5 and the photointerrupters 12 to 15 constitute the control means described in the claims.

Reference numeral 9 denotes a display / reproduction circuit including an LCD and the like. Reference numeral 10 denotes an acceleration sensor (vibration detecting means) for detecting vibration (shock vibration) due to a drop or the like applied to the camera. Reference numeral 11 denotes an operation member for performing various operation inputs in the camera.

In the camera configured as described above, when the power is turned on by the operation member 11, the microcomputer 5
The zoom lens, focus lens, zoom finder and zoom strobe are connected to the respective
7, 8 and reset photo interrupters 12, 13, 1
The drive is performed to a predetermined initial position at which each reset position is detected using the signals 4 and 15.

Thereafter, when an operation for changing the zoom magnification to the tele side or the wide side is performed through the operation member 11, the zoom lens, the focus lens, the zoom finder, and the zoom strobe are respectively driven by the drive motors 1,
2, 7, 8 are driven and moved.

When a release operation is performed on the operation member 11, a photographing operation is performed. By this photographing operation, the optical image formed on the image sensor 3 is photoelectrically converted. The photoelectrically converted signal is subjected to electrical processing by a signal processing circuit 4, recorded in a recording circuit 6, and displayed as an image in a display / reproduction circuit 9.

FIG. 1 shows the configuration of a photographing optical system and a finder optical system in the present camera. FIG. 10 shows a movement trajectory from the telephoto end to the wide end of the zoom lens and the focus lens of the photographing optical system.

Reference numeral 22 denotes a focus moving cylinder for holding a focus lens as a first group lens. This focus lens also functions as a compensator for the zoom lens, and moves along the curve in FIG. 10 as the zoom lenses of the second and fourth groups move linearly along the movement locus shown in FIG.

FIG. 3 shows the relationship between the focus moving cylinder 22 and the focus drive motor 2. The focus moving cylinder 22 is supported by guide bars 32 and 33 so as to be movable only in the optical axis direction. A rack 23 is attached to the focus moving cylinder 22. Rack 2
Numeral 3 meshes with the screw screw shaft 31 so as to sandwich the screw screw shaft 31 integrated with the focus drive motor 2 which is a stepping motor by a spring (not shown). The motor 2 rotates and the screw screw shaft 31 rotates. Then, the rack 23 moves in the optical axis direction integrally with the focus moving cylinder 22 and the focus lens.

FIG. 6 is a front view of the focus lens. A state in which the light shielding plate portion 22a formed in the focus moving cylinder 22 enters and exits between the light emitting part and the light receiving part of the focus resetting photointerrupter 13 due to the movement of the focus moving cylinder 22, and shields light between the light emitting part and the light receiving part. As a result, the output of the photo-interrupter 13 changes. Then, the microcomputer 5 detects the output, and a position where the light is switched from the light-shielded state to the light-shielded state is defined as a focus reset position.

FIG. 4 shows the details of the rack member 23 and the screw shaft 31. In the state of FIG.
The rack 23 has four teeth 23a on the left side in the figure and one movable right tooth 2 which is pressed and elastically deformed by a spring (not shown).
3b meshes with the screw screw shaft 31.

In this state, when a strong shock or the like is applied to the camera in this state, a large force is applied to the focus moving cylinder 22 and the teeth 23a of the rack 23 try to get over the teeth of the screw shaft 31, so that the teeth 23a The gap between the teeth 23b is increased, and the rack 23 moves in a direction in which the engagement is loosened, as shown in FIG.

Reference numeral 23c denotes an opposing tooth for suppressing the rack 23 from climbing over the tooth.
some screw screw shaft 3 despite the presence of c
Overcoming one tooth (hereinafter referred to as tooth skipping), FIG. 4
As shown in (C), the moved teeth 23a of the rack 23 mesh with the screw shaft 31 and come to rest.

In FIG. 1, reference numeral 21 denotes a zoom moving cylinder for holding a zoom lens. FIG. 7 shows the relationship between the zoom moving barrel 71 and the zoom drive motor 1. The zoom moving cylinder 21 is supported by guide bars 74 and 75 so as to be movable only in the optical axis direction. A rack 73 is attached to the zoom moving cylinder 21. Rack 7
33 is a screw screw shaft 7 integrated with the zoom drive motor 1 as a stepping motor by a spring (not shown).
When the motor 1 rotates and the screw screw shaft 72 rotates, the rack 73 moves in the optical axis direction integrally with the zoom moving cylinder 21 and the zoom lens. .

A light shielding plate 21a is formed on the zoom movable cylinder 21. The light shielding plate 22a is
The movement of 1 causes the zoom reset photo-interrupter 12 to enter and exit between the light projecting unit and the light receiving unit to enter a state in which light is blocked between the projecting / light receiving unit and a state in which light is not blocked.
The output of the photo interrupter 12 changes. Then, the microcomputer 5 detects the output, and the position where the light is switched from the light-shielded state to the light-shielded state is defined as a zoom reset position.

A rack 73 attached to the zoom movable barrel 21 when a strong shock or other vibration is applied to the camera.
The relationship between the screw screw shaft 72 and the rack 23 attached to the focus moving cylinder 22 and the screw screw shaft 72
This is the same as the relationship with 2.

FIG. 8 shows the structure of the zoom finder. The rotation of the finder drive motor 7 drives a finder cam plate (not shown) arranged on the far side of the drawing, and the zoom lens 81 of the finder moves in the optical axis direction.

As in the case of the photographing optical system, a light-blocking plate 81a is formed on the movable barrel holding the finder zoom lens 81, and the light-shielding plate portion 81a projects the finder reset photointerrupter 14 by moving the movable barrel. The output of the photo-interrupter 14 changes when light enters and exits between the optical unit and the light receiving unit to be in a state in which light is interrupted between the light emitting unit and the light receiving unit. Then, the microcomputer 5 detects the output, and the position where the light is switched from the light-shielded state to the light-shielded state is defined as a finder reset position.

The focus finder is different from the zoom finder in that when a strong shock or other vibration is applied to the camera, the engagement relationship between the finder cam plate and the finder drive motor 7 may be deviated. There is the same problem as the relationship between the rack 23 attached to the bracket 22 and the screw shaft 72.

FIG. 9 shows the structure of a zoom strobe. The zoom strobe includes a light source section including a xenon tube 91 and a reflection shade 92, a holder 94 for holding the light source section, a guide shaft 96 for guiding the holder 94 in the optical axis direction, and a strobe driving motor. 8 and a rack 95 attached to the holder 94 and engaged with the screw screw shaft 8a. When the screw screw shaft 8a rotates by the drive of the strobe drive motor 8, the holder 94 moves back and forth in the optical axis direction due to the meshing action of the screw screw shaft 8a and the rack 95.

A diffusing plate 97 is held at the front end of the zoom strobe. By changing the distance between the diffusing plate 97 and the holder 94 (that is, the light source unit), the strobe irradiation angle changes.

A light-shielding plate 93 is formed on the holder 94 in the same manner as the moving barrel of the photographing optical system.
Is moved between the light emitting part and the light receiving part of the strobe reset photo-interrupter 15 by the movement of the holder 94, so that a state where the light is not shielded between the light emitting part and the light receiving part is obtained. Output changes. Then, the output is detected by the microcomputer 5, and the position where the light is switched from the light-shielded state to the light-shielded state is defined as a strobe reset position.

The relationship between the rack 95 attached to the holder 94 and the screw screw shaft 8a when a strong shock or the like is applied to the camera is based on the focus moving cylinder 22.
This is the same as the relationship between the rack 23 attached to the bracket and the screw screw shaft 72.

FIG. 5 is a flowchart showing the operation of the camera. When the power switch is turned on in step 51, the camera is initialized in step 52, and the zoom lens, focus lens, zoom finder, and zoom strobe of the photographing optical system are driven to the above-described reset positions. At this time, the zoom finder and the zoom strobe are adjusted in advance so as to have the same angle of view as the photographing optical system.

Thereafter, the state of the zoom switch of the operation member 11 is detected in step 53, and when the zoom switch is turned on, the process proceeds to step 54, and the zoom operation state is set. Specifically, the zoom lens and the focus lens of the photographing optical system are driven in the tele or wide direction specified by the zoom switch, and the zoom finder and the zoom strobe are driven.

Here, with respect to the focus lens also serving as a compensator, the focus movement locus shown in FIG. 10 is stored in the memory of the microcomputer 5 with respect to the position of the zoom lens. For this reason, with the movement of the zoom lens,
The focus lens is always driven so as not to go out of a position from infinity to a close range according to the position of the zoom lens.

The locus of movement of the zoom finder and zoom strobe is stored in the memory of the microcomputer 5 in order to cause a change in the angle of view similar to the change in the angle of view accompanying the movement of the zoom lens of the photographing optical system. For this reason, as the zoom lens of the photographing optical system moves, the zoom finder and the zoom strobe are always driven along the movement locus stored in the memory of the microcomputer 5 so as to match the angle of view of the zoom lens.

When the zoom operation is completed in this way or when the operation of the zoom switch is not detected in step 53, the position of the zoom lens at that time is stored in the memory in step 55.

Thereafter, at step 56, the intensity (acceleration) of the vibration acting on the camera is detected by the acceleration sensor 10. The acceleration sensor 10 may be of any type as long as it can measure the magnitude and intensity of the vibration, and for example, a vibration gyro may be used. Further, it may also be used as a vibration sensor used for a vibration isolator for preventing image blur mounted on a camera. As a result, a reset function described later can be provided without increasing the number of camera parts.

Here, when the output of the acceleration sensor 10 exceeds a certain threshold value (predetermined level), a large impact is applied to the camera, and the zoom lens, the focus lens, and the holder 94 in the zoom strobe are moved by the above-described tooth jump. As in the case of the camera initialization, as in the case of initializing the camera, there is a possibility that the finder cam plate in the zoom finder may be displaced from the engagement with the finder drive motor. The zoom lens, focus lens, zoom finder, and zoom strobe are driven to return to their respective reset positions.

When the zoom lens and the focus lens of the photographing optical system are driven to return to the respective reset positions,
The positional relationship between the zoom lens and the focus lens, each of which may be displaced by an impact, can be reliably returned to the initial state, which is an appropriate state.

Further, the zoom finder and the zoom strobe are driven to return to the respective reset positions, so that
The relationship between the angle of view of the photographing optical system, the angle of view of the finder, and the irradiation angle of the strobe, which may be displaced by the impact, can be reliably returned to the initial state, which is an appropriate state.

After the return drive to each reset position is performed in step 57, the zoom lens, focus lens, zoom finder and zoom strobe are immediately moved from each reset position to step 5 in step 58.
It drives to each position memorized by 5. Thus, the zoom lens, the focus lens, the zoom finder, and the zoom strobe can be automatically returned to the state before the impact was applied.

Subsequently, at step 59, it is determined whether or not the release switch has been turned on.
If N, the process proceeds to step 60 where AE / AF
Then, a photographing operation is performed in step 61. If the release switch has not been turned on, the process returns to step 53.

In the present embodiment, a case has been described in which not only the zoom lens and the focus lens of the photographing optical system but also the zoom finder and the zoom strobe are reset when an impact is applied. If the zoom strobe is mechanically strong against impact, only the lens on the photographic optical system side may be reset to return to the position before the impact. In this case, the time and power consumption required for the reset operation can be saved.

In this embodiment, a digital camera has been described. However, the present invention can be applied to a silver halide camera or a video camera having an optical finder. Further, the present invention can be applied to various optical devices having a movable optical element.

[0052]

As described above, according to the present invention,
If vibration (impulsive vibration or the like) exceeding a predetermined level is applied to the apparatus main body, for example, there is a possibility that the optical element is displaced with respect to a driving member for driving the optical element, the optical element is moved to the initial position. , And then the optical element can be driven based on the initial position. It is possible to reliably prevent the state shift and the shift of the irradiation angle of the zoom strobe from the zoom state of the photographing optical system. By applying the present invention to each of the photographing optical system, the optical viewfinder and the zoom strobe in the apparatus, a difference in the angle of view between the photographing optical system and the optical viewfinder occurs due to the influence of a large vibration, and the photographer's It is possible to reliably prevent the photographing from being performed unintentionally or prevent the strobe irradiation from extending to the entire photographing screen.

The position of the optical element before the detected vibration exceeds the predetermined level is stored, and after the optical element is driven to return to the initial position, the optical element is driven to the stored position. Then, after a large vibration is applied,
Shooting or the like can be continued in the same state as immediately before the vibration is applied.

[Brief description of the drawings]

FIG. 1 is a sectional view of a photographing lens and an optical viewfinder in a digital camera according to an embodiment of the present invention.

FIG. 2 is an electric circuit block diagram of the digital camera.

FIG. 3 is a diagram showing a relationship between a focus moving cylinder and a focus drive motor in the photographing lens.

FIG. 4 is an enlarged view showing a relationship between a rack of the focus moving cylinder and a screw screw shaft of a focus drive motor.

FIG. 5 is an operation flowchart of the digital camera.

FIG. 6 is a front view around the focus moving cylinder.

FIG. 7 is a diagram showing a relationship between a zoom moving cylinder and a zoom drive motor in the photographing lens.

FIG. 8 is a configuration diagram of an optical zoom finder in the digital camera.

FIG. 9 is a configuration diagram of a zoom strobe in the digital camera.

FIG. 10 is a diagram showing a movement locus of the photographing lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Zoom moving cylinder 22 Focus moving cylinder 12, 13, 14, 15 Photo interrupter 23, 73 Rack 31, 72, 8a Screw screw shaft 91 Xenon tube 92 Reflector shade

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/238 H04N 5/238 Z

Claims (10)

[Claims] An optical device having an optical element movable with reference to a predetermined initial position, a vibration detecting means for detecting a vibration applied to the apparatus main body, and the vibration detected by the vibration detecting means has a predetermined level. Control means for returning the optical element to the initial position when the optical element is exceeded. 2. A structure in which the optical element and a driving member for driving the optical element allow a movement of the optical element with respect to the driving member by the impact vibration when an impact vibration is applied to an apparatus main body. The control means, when the vibration detected by the vibration detection means exceeds a level corresponding to the shock vibration,
The optical device according to claim 1, wherein the optical element is returned to the initial position. 3. The apparatus according to claim 2, wherein the driving member is a screw screw shaft that is driven to rotate, and the connecting unit is a rack attached to the optical element.
An optical device according to claim 1. 4. A photographing optical system wherein a focus lens driven at the time of focus adjustment is driven in the optical axis direction in accordance with the optical axis direction drive of the zoom lens driven at the time of zooming. 4. The optical device according to claim 1, wherein the optical device is one or both of the zoom lens and the focus lens. 5. 5. An apparatus according to claim 1, further comprising an optical finder for performing a zoom operation in accordance with a zoom operation of a photographing optical system, wherein said optical element is a lens constituting said optical finder. The optical device according to any one of the above. 6. An optical finder for performing a zoom operation in accordance with a zoom operation of a photographic optical system, wherein the control means controls a lens constituting the photographic optical system and a lens constituting the optical finder, respectively. The optical device according to claim 1, wherein the optical device is returned to an initial position. 7. A zoom strobe capable of changing an illumination angle of illumination light in accordance with a zoom operation of a photographing optical system, wherein the optical element is a light source unit or a lens constituting the zoom strobe. Claims 1 to 3 characterized by the above-mentioned.
The optical device according to any one of the above. 8. A zoom strobe which can change an irradiation angle of illumination light in accordance with a zoom operation of a photographing optical system, wherein the control means comprises a lens constituting the photographing optical system and the zoom strobe. The optical device according to any one of claims 1 to 3, wherein each of the light source unit and the lens unit is returned to the initial position. 9. An image blur prevention control for displacing an optical element in a photographing optical system for detecting a shake of an apparatus main body and preventing an image shake, wherein the vibration detecting means includes: 9. The optical device according to claim 1, wherein the optical device also serves as a means for detecting a shake for performing a shake prevention control. 10. The control means stores a position of the optical element before the vibration detected by the vibration detection means exceeds a predetermined level, and performs a drive for returning the optical element to an initial position. 10. The optical device according to claim 1, wherein the optical element is driven to the stored position.