JP4587147B2 - Optical device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical apparatus having a movable optical element such as a silver salt camera, a digital camera, a video camera and the like.
[0002]
[Prior art]
An imaging optical system and an optical viewfinder in a camera are configured to drive several lenses in the optical axis direction for zooming, focusing, and the like. Then, as the drive mechanism for driving the lens, a screw shaft threaded to the drive shaft of the stepping motor, engagement with the rack attached to the movable lens frame that is guided in the optical axis direction by the guide bar, rotation of the stepping motor In some cases, the lens is driven by the meshing action of the screw screw shaft and the rack.
[0003]
In this case, a memory such as a computer stores the same cam locus as when the zoom lens or focus lens (compensator lens) is driven by the cam barrel, and the zoom lens or focus lens is It is moved and zoomed by computer control along the cam locus.
[0004]
Further, when using the drive mechanism as described above, the screw screw shaft and the rack are disengaged when subjected to shock vibration due to dropping or the like, and the movement of the moving lens group with respect to the screw screw shaft due to the vibration is allowed. By configuring, it is often the case that a failure due to the biting between the rack and the screw screw shaft does not occur at the time of impact.
[0005]
[Problems to be solved by the invention]
However, as described above, in the case of using a drive mechanism configured to perform the zoom operation by the engagement of the screw screw shaft and the rack and to disengage the screw screw shaft and the rack by shock vibration, the zoom lens or the When the meshing position of the rack on the focus lens side and the screw screw shaft is shifted, the zoom lens and the focus lens may be out of the cam locus and the focus may be shifted.
[0006]
Also, when zooming the optical viewfinder and shooting optical system independently, when the zoom lens is displaced due to impact, the relationship between the viewfinder and the shooting optical system shifts, and the viewfinder matches the angle of view of the shooting optical system. There is also a risk that the angle of view cannot be obtained.
[0007]
Similarly, the relationship between the zoom state of the photographing optical system and the irradiation angle of the zoom strobe may deviate, and there is a possibility that proper flash irradiation may not be performed on the subject.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, in an optical device having an optical element that can move with reference to an initial position, vibration detection means for detecting vibration applied to the main body of the apparatus, and detection by the vibration detection means. Control means for moving the optical element back to the initial position when the vibration exceeds a threshold value (predetermined level) and then moving the optical element to the position of the stored optical element when the vibration exceeds the threshold value ; Provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, FIG. 2 shows an electric circuit configuration in a digital camera (optical apparatus) according to an embodiment of the present invention.
[0013]
In this figure, reference numeral 1 denotes a zoom lens driving motor for driving a zoom lens (photographing lens) of the photographing optical system, and reference numeral 12 denotes a zoom lens reset photointerrupter for detecting switching when the zoom lens passes the zoom reset position. .
[0014]
Reference numeral 2 denotes a focus lens driving motor that drives a focus lens (photographing lens) of the photographing optical system, and reference numeral 13 denotes a focus lens reset photointerrupter that detects switching when the focus lens passes the focus reset position.
[0015]
3 is an image sensor such as a CCD, 4 is a signal processing circuit for processing a signal from the image sensor 3, and 6 is a recording circuit for recording a signal processed by the signal processing circuit 4. A microcomputer 5 controls the entire operation of the camera.
[0016]
Reference numeral 7 denotes a finder drive motor for driving the optical zoom finder, and reference numeral 14 denotes a finder reset photointerrupter for detecting switching when the zoom finder passes the finder reset position.
[0017]
Reference numeral 8 denotes a strobe driving motor for driving the irradiation angle change of the zoom strobe, and reference numeral 15 denotes a strobe reset photointerrupter for detecting switching when the zoom strobe passes the strobe reset position. The microcomputer 5 and the photo interrupters 12 to 15 constitute control means as defined in the claims.
[0018]
Reference numeral 9 denotes a display / reproduction circuit including an LCD or the like. Reference numeral 10 denotes an acceleration sensor (vibration detecting means) for detecting vibration (impact vibration) caused by dropping or the like applied to the camera. Reference numeral 11 denotes an operation member for performing various operation inputs in the camera.
[0019]
In the camera configured as described above, when the operation member 11 is turned on, the microcomputer 5 resets the zoom lens, the focus lens, the zoom finder, and the zoom strobe with their respective drive motors 1, 2, 7, and 8 and for resetting. The photo interrupters 12, 13, 14, and 15 are used to drive to a predetermined initial position where each reset position is detected.
[0020]
Thereafter, when an operation of changing the zoom magnification to the tele side or the wide side is performed through the operation member 11, the zoom motor, the focus lens, the zoom finder, and the zoom strobe are driven by the respective drive motors 1, 2, 7, and 8. Move.
[0021]
When a release operation is performed with 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 the signal processing circuit 4, recorded in the recording circuit 6, and displayed as an image in the display / reproduction circuit 9.
[0022]
FIG. 1 shows a configuration of a photographing optical system and a finder optical system in the camera. FIG. 10 shows the movement locus of the zoom lens and focus lens of the photographing optical system from the tele end to the wide end.
[0023]
Reference numeral 22 denotes a focus moving cylinder that holds a focus lens as a first lens group. This focus lens also serves as a compensator for the zoom lens, and moves along the curve in FIG. 10 as the second and fourth zoom lenses move linearly along the movement locus shown in FIG.
[0024]
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. The rack 23 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. When rotating, the rack 23 moves in the optical axis direction together with the focus moving cylinder 22 and the focus lens.
[0025]
FIG. 6 shows a front view of the focus lens portion. A state in which the light shielding plate part 22a formed on the focus moving cylinder 22 enters and exits between the light projecting part and the light receiving part of the focus reset photointerrupter 13 by the movement of the focus moving cylinder 22, and shields the light projecting / receiving part from light. As a result, the output of the photo interrupter 13 changes. Then, the microcomputer 5 detects the output, and the position where the light is blocked from the light shielded state is set as the focus reset position.
[0026]
FIG. 4 shows details of the rack member 23 and the screw screw shaft 31. In the state of FIG. 4A, the rack 23 is engaged with the screw screw shaft 31 by four teeth 23a on the left side in the figure and one movable right tooth 23b that is pressed and deformed by a spring (not shown). Yes.
[0027]
In this state, when a strong vibration such as a shock is applied to the camera, 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 screw shaft 31, so that the teeth 23a and 23b As shown in FIG. 4B, the rack 23 moves in the direction in which the meshing is loosened.
[0028]
23c is a counter tooth that suppresses the rack 23 from getting over the teeth. However, when the impact is strong, the tooth of the screw screw shaft 31 is overtaken despite the presence of the counter tooth 23c (hereinafter, this is referred to as the tooth skipping). As shown in FIG. 4C, the teeth 23a of the moved rack 23 mesh with the screw screw shaft 31 and come to rest.
[0029]
In FIG. 1, reference numeral 21 denotes a zoom moving cylinder that holds a zoom lens. FIG. 7 shows the relationship between the zoom moving cylinder 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. The rack 73 meshes with the screw screw shaft 72 so as to sandwich the screw screw shaft 72 integrated with the zoom drive motor 1 as a stepping motor by a spring (not shown). The motor 1 rotates and the screw screw shaft 72 rotates. When rotated, the rack 73 moves together with the zoom moving cylinder 21 and the zoom lens in the optical axis direction.
[0030]
The zoom moving cylinder 21 is formed with a light shielding plate portion 21a . The light shielding plate portion 21a is moved between the light projecting portion and the light receiving portion of the zoom reset photo interrupter 12 by the movement of the zoom moving barrel 21. The output of the photo interrupter 12 changes when the light projecting / receiving section is shielded from light and when it is not shielded. A position where the microcomputer 5 detects the output and switches from the light shielding state to the light shielding state is set as a zoom reset position.
[0031]
The relationship between the rack 73 attached to the zoom moving cylinder 21 and the screw screw shaft 72 when the camera is subjected to vibration such as a strong impact is the relationship between the rack 23 attached to the focus moving cylinder 22 and the screw screw shaft 31. It is the same.
[0032]
FIG. 8 shows the configuration of the zoom finder. The rotation of the finder drive motor 7 drives a finder cam plate (not shown) arranged on the back side of the drawing in the drawing, and the zoom lens 81 of the finder moves in the optical axis direction.
[0033]
Similar to the imaging optical system, the movable barrel that holds the viewfinder zoom lens 81 are light-shielding plate portion 81a is formed, the light shielding plate portion 81a is, the light projecting portion of the finder reset photointerrupter 14 by the movement of the moving cylinder The light output from the photointerrupter 14 changes as the light enters and exits between the light receiving unit and the light receiving unit, and the light projecting / receiving unit is shielded from light and the light is not shielded. And the microcomputer 5 detects the output, and the position switched from the light-shielded state to the non-light-shielded state is set as the finder reset position.
[0034]
This zoom finder is attached to the focus moving cylinder 22 in that there is a possibility that the engagement relationship between the finder cam plate and the finder drive motor 7 may be shifted when vibration such as a strong impact is applied to the camera. There is a problem similar to the relationship between the rack 23 and the screw screw shaft 31 .
[0035]
FIG. 9 shows a configuration of the zoom strobe. The zoom strobe includes a light source unit composed of a xenon tube 91 and a reflective shade 92, a holder 94 for holding the light source unit, a guide shaft 96 for guiding the holder 94 in the optical axis direction, and a strobe driving motor. 8 and a screw screw shaft 8a provided integrally with the rack 8, and a rack 95 attached to the holder 94 and meshing with the screw screw shaft 8a. When the screw screw shaft 8a is rotated by driving the strobe drive motor 8, the holder 94 moves back and forth in the optical axis direction by the meshing action of the screw screw shaft 8a and the rack 95.
[0036]
A diffusion plate 97 is held at the front end of the zoom strobe, and the strobe illumination angle changes by changing the distance between the diffusion plate 97 and the holder 94 (that is, the light source unit).
[0037]
A light shielding plate portion 93 is formed on the holder 94 in the same manner as the moving cylinder of the photographing optical system. The light shielding plate portion 93 is moved between the light projecting portion and the light receiving portion of the strobe resetting photo interrupter 15 by the movement of the holder 94. The output of the photo-interrupter 15 is changed by entering and exiting between the state where the light is projected and light-shielded between the light projecting and light receiving portions. Then, the microcomputer 5 detects the output, and the position where the light is blocked from the light-shielded state is set as the strobe reset position.
[0038]
The relationship between the rack 95 attached to the holder 94 and the screw screw shaft 8a when vibration such as a strong impact is applied to the camera is the same as the relationship between the rack 23 attached to the focus moving cylinder 22 and the screw screw shaft 31. It is.
[0039]
FIG. 5 shows an operation flowchart 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 reset positions described above. 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.
[0040]
Thereafter, in step 53, the state of the zoom switch in the operation member 11 is detected, and when the zoom switch is on, the process proceeds to step 54 to enter a zooming operation state. Specifically, the zoom lens and the focus lens of the photographing optical system are driven in the tele or wide direction designated by the zoom switch, and the zoom finder and the zoom strobe are driven.
[0041]
Here, with respect to the focus lens that also serves as the 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, as the zoom lens moves, the focus lens is always driven so as not to come out from the position from infinity to the closest position according to the position of the zoom lens.
[0042]
Further, for the zoom finder and the zoom strobe, the movement trajectory for causing the same change in the angle of view as the movement of the zoom lens of the photographing optical system is stored in the memory of the microcomputer 5. For this reason, with the movement of the zoom lens of the photographing optical system, the zoom finder and the zoom strobe are driven along the movement locus stored in the memory of the microcomputer 5 so as to always match the angle of view of the zoom lens.
[0043]
When the zoom operation is completed in this way, or when the operation of the zoom switch is not detected in step 53, the zoom lens position at that time is stored in the memory in step 55.
[0044]
Thereafter, in step 56, the acceleration sensor 10 detects the intensity of vibration (acceleration) acting on the camera. The acceleration sensor 10 may be anything that can measure the magnitude / intensity of vibration, for example, a vibration gyro. Further, it may also be used as a vibration sensor used in an image stabilization device mounted on the camera for preventing image blur. As a result, a reset function described later can be provided without increasing the number of parts of the camera.
[0045]
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 connected to each screw screw shaft by the above-described tooth skipping. As with the camera initialization, the zoom lens of the photographic optical system may be moved, and the engagement relationship between the finder cam plate and the finder drive motor in the zoom finder may be shifted. Drive the focus lens, zoom finder, and zoom strobe back to their reset positions.
[0046]
The zoom lens and focus lens of the photographic optical system are driven back to their respective reset positions, ensuring that the positional relationship between the zoom lens and focus lens, which may have been displaced due to impact, is in the proper initialization state. Can be returned.
[0047]
In addition, the zoom finder and zoom strobe are driven back to their respective reset positions, so that the relationship between the angle of view of the photographic optical system, which may have been displaced due to impact, the angle of view of the finder, and the illumination angle of the strobe in an appropriate state. A certain initialization state can be reliably restored.
[0048]
Thus, after returning to the reset positions in step 57, the zoom lens, focus lens, zoom finder, and zoom strobe are immediately driven from the reset positions to the positions stored in step 55 in step 58. . Thereby, the zoom lens, the focus lens, the zoom finder, and the zoom strobe can be automatically returned to the state before the impact is applied.
[0049]
Subsequently, in step 59, it is determined whether or not the release switch is turned on. When the release switch is turned on, the process proceeds to step 60 to perform a shooting preparation operation such as AE / AF, and then in step 61. Perform the action. If the release switch is not turned on, the process returns to step 53.
[0050]
In this embodiment, the case where the zoom finder and the zoom strobe are reset when not only the zoom lens and the focus lens of the photographing optical system when an impact is applied has been described. If the mechanism is strong against an impact, only the lens on the photographing 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.
[0051]
In this embodiment, a digital camera has been described. However, the present invention can also be applied to a silver salt camera and a video camera having an optical viewfinder. Further, the present invention can be applied to various optical devices provided with a movable optical element.
[0052]
【The invention's effect】
As described above, according to the present invention, when vibration exceeding the threshold (predetermined level) (impact vibration or the like) is applied to the apparatus body, the optical element (zoom) before the detected vibration exceeds the threshold (predetermined level). Lens, focus lens, optical viewfinder, zoom strobe) position, and after returning the optical element to its initial position, this optical element is driven to the stored position, preventing the effects of optical element displacement, In addition, it is possible to continue shooting in the same state as before the vibration was applied.
[Brief description of the drawings]
FIG. 1 is a cross-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 illustrating a relationship between a focus moving cylinder and a focus drive motor in the photographing lens.
FIG. 4 is an enlarged view showing the relationship between the rack of the focus moving cylinder and the screw screw shaft of the 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 illustrating 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]
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 Reflecting shade

Claims (6)

A zoom lens that can move in the optical axis direction with reference to the initial position during zooming, and a zoom lens that is driven during zooming. A photographing optical system including a focus lens movable in the optical axis direction as
Vibration detecting means for detecting vibration applied to the apparatus body;
Storing a position of the zoom lens and the focus lens, when the detected vibration exceeds the threshold value by the vibration detecting means, said zoom lens and said focus lens, in after returning to each of the initial position, the An optical apparatus comprising: control means for moving to a position of the zoom lens and the focus lens stored when the vibration exceeds the threshold value . An imaging optical system that can move in the optical axis direction with reference to the initial position,
An optical viewfinder that performs a zoom operation with a zoom operation of the photographing optical system with reference to an initial position;
Vibration detecting means for detecting vibration applied to the apparatus body;
Storing the position of the photographing optical system and the optical viewfinder, the when the detected vibration exceeds the threshold value by the vibration detecting means, said imaging optical system and the optical viewfinder, the after returning to each of the initial position An optical apparatus comprising: a control unit configured to move to the position of the photographing optical system and the optical finder stored when the vibration exceeds the threshold value . An imaging optical system that can move in the optical axis direction with reference to the initial position,
A zoom strobe that can change the illumination angle of illumination light with the zoom operation of the photographing optical system with reference to the initial position;
Vibration detecting means for detecting vibration applied to the apparatus body;
Storing the position of the photographing optical system and the zoom strobe, the when the detected vibration exceeds the threshold value by the vibration detecting means, said imaging optical system and the zoom strobe, after to return respectively to the initial position An optical apparatus comprising: the photographing optical system that is stored when the vibration exceeds the threshold value; and a control unit that moves to the position of the zoom strobe .   The photographing optical system and a driving member for driving the photographing optical system are coupled by a coupling means having a structure that allows movement with respect to the driving member when vibration corresponding to the threshold acts on the apparatus main body. The optical device according to claim 1, wherein the optical device is provided. The drive member is a screw screw shaft that is rotationally driven,
The optical apparatus according to claim 4, wherein the connecting unit is a rack attached in the photographing optical system. It is possible to perform image blur prevention control for displacing the shake correction device in the photographing optical system in order to detect the shake of the apparatus main body and prevent the image blur.
6. The optical apparatus according to claim 1, wherein the vibration detecting unit is also used as a unit for detecting a shake in order to perform the image blur prevention control.

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