JP2017015936A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device which allows an outer shape of a front cover to be miniaturized and is capable of acquiring position information of a plurality of members by using one position detection unit.SOLUTION: The optical device includes: a barrel member movable along an optical axis; a holding member which holds an optical member and is movable along the optical axis; driving means of which the subject side a lead screw parallel with the optical axis is attached to; a moving member which is engaged with the lead screw and is held by the holding member; a detection unit which detects an initial position of the holding member when the holding member is located in a first position, and detects an initial position of the barrel member when the holding member is located in a second position nearer to the image side than the first position; and an elastic member which is disposed between the moving member and the holding member and has an elastic force to increase a space between the moving member and the holding member. The holding member is moved to the first position in accordance with movement of the moving member and then compresses the elastic member to move to the second position together with the barrel member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical apparatus.

  In recent years, an imaging apparatus such as a digital camera has been required to be small and thin at the same time as the magnification is increased. In addition, the imaging apparatus is also required to include a small focus mechanism that can perform a high-speed and stable operation. Patent Document 1 discloses an imaging apparatus that can achieve small size and thinness and stable lens barrel driving while having a high magnification.

Japanese Patent No. 5361666

  In the imaging apparatus disclosed in Patent Document 1, a focus motor is disposed in the vicinity of the front portion of the imaging apparatus so that a lead screw provided in the focus motor extends toward the image forming side. The focus motor is disposed in the front cover portion 210 that protrudes from the front surface of the imaging device 200 shown in FIG. In recent years, it has been required to further reduce the outer shape of the front cover unit 210 without increasing the thickness of the imaging device 200 (the arrow portion in the figure). If the outer shape of the front cover part 210 is further reduced, the focus motor disclosed in Patent Document 1 cannot be disposed in the front cover part 210 and the design is impaired.

  Moreover, in the imaging device disclosed in Patent Literature 1, position information of a plurality of members is acquired using one position detection unit. If the focus motor is arranged on the imaging side so that the lead screw is arranged in the front cover 210, the position information of the zoom lens is updated after the position information of the focus lens is updated when the power is turned off. It cannot be updated. This is because after the position information of the focus lens is updated, the lens holding member provided with the light shielding portion is in close contact with the nut screwed with the lead screw, and therefore the lens holding member cannot be further lowered, and the output of the light shielding portion is This is because it cannot be changed.

  In view of such a problem, the present invention provides an optical device capable of reducing the outer shape of the front cover part and acquiring position information of a plurality of members using one position detection part. For the purpose.

  An optical device according to one aspect of the present invention includes a lens barrel member movable along an optical axis, a holding member that holds the optical member and is movable along the optical axis, and a lead parallel to the optical axis. A driving means having a screw attached to the object side, a moving member screwed to the lead screw and held by the holding member, and an initial position of the holding member when the holding member is located at the first position A detection unit that detects an initial position of the barrel member when the holding member is positioned at a second position closer to the imaging side than the first position, and the moving member and the holding member An elastic member having an elastic force that is disposed between the moving member and the holding member, and the holding member moves to the first position along with the movement of the moving member; By compressing the elastic member With serial barrel member thus being moved to the second position.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to make the external shape of a front cover part small, the optical apparatus which can acquire the positional information on a some member using one position detection part can be provided.

1 is an external perspective view of a camera as an optical device according to an embodiment of the present invention. It is a perspective view of a focus mechanism. It is a schematic diagram of a lens barrel. It is a figure which shows the state which acquires the positional information on a lens holding member. It is a figure which shows the state which acquires the positional information on a collapsible lens barrel member. It is a figure which shows the state inside the retractable lens barrel member in the state of FIG. It is a top view of the conventional imaging device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted. In this embodiment, a lens barrel is used as an example of the optical apparatus of the present invention. Note that an imaging apparatus including the lens barrel of this embodiment also corresponds to the optical apparatus of the present invention.

  FIG. 1 is an external perspective view of an image pickup apparatus 1 including an optical device according to an embodiment of the present invention. The imaging device 1 includes a camera housing 10, a lens barrel 20, a lens barrier unit 30, a light emitting unit 40, and a release button 50. The camera housing 10 houses components such as a shutter mechanism. The lens barrel 20 is disposed in front of the camera housing 10 and changes the focal length of the imaging lens. The lens barrier unit 30 is disposed in front of the lens barrel 20 and opens and closes the optical path of the photographing lens according to the power supply state (ON state or OFF state) of the imaging device 1. The light emitting unit 40 constitutes a part of a strobe device that irradiates a subject with illumination light, and is disposed so as to be housed in the camera housing 10. The release button 50 is disposed on the upper surface of the camera housing 10 and starts an imaging preparation operation (focus adjustment operation and photometry operation) and a photographing operation (exposure to an image sensor such as a film or a CCD). FIG. 2 is a perspective view of a focus mechanism as a lens driving mechanism as viewed from the subject side. FIG. 3 is a schematic diagram of the lens barrel when the lens holding member 101 is located on the subject side (arrow + side). The lens holding member 101 holds a photographing lens (optical member) 114. The sensor holding member 105 includes the steadying portion 113 of the lens holding member 101. The tension spring (biasing member) 106 is attached between the sensor holding member 105 and the attachment portion 107 of the lens holding member 101, and biases the lens holding member 101 to the image forming side (arrow-side).

  A feed screw mechanism is configured by the motor 100 and the lead screw 103 provided in the motor 100. The lead screw 103 is provided so as to be parallel to the optical axis and located on the subject side with respect to the motor 100. The nut (moving member) 104 is screwed with the male screw of the lead screw 103 and is held by the nut holding convex portion 115 of the lens holding member 101. Therefore, when the lead screw 103 rotates, the lens holding member 101 advances and retreats in the optical axis direction by the feed screw mechanism. Between the nut 104 and the lens holding member 101, an elastic member 112 having an elastic force that widens the gap between the nut 104 and the lens holding member 101 is disposed. Since the elastic force of the elastic member 112 is greater than the weight of the lens holding member 101 and the imaging lens 114, the lens holding member 101 is pushed up toward the subject side. The lower surface of the nut 104 is in contact with the position restricting portion 101a of the lens holding member 101, whereby the position of the lens holding member 101 in the optical axis direction is restricted.

  The lens barrel includes a photo interrupter (detection member) 108 capable of detecting position information (initial position) of the lens holding member 101 and the collapsible barrel member 109, and a collapsible barrel member movable along the optical axis. (Lens barrel member) 109 is provided. The lens holding member 101 is provided with a light shielding plate (light shielding portion) 110 that can shield the photo interrupter 108.

  Next, a method for updating the position information of each member when the power is turned on from the power on state will be described with reference to FIGS.

  First, when the power is turned off from the state shown in FIG. 3, the lens holding member 101, the elastic member 112, and the nut 104 are moved together to the image forming side by the feed screw mechanism. When the lens holding member 101 moves to the image forming side, the light shielding plate 110 shields the photo interrupter 108 from light. Therefore, the output of the photo interrupter 108 changes. By reading the change in the output, the position information of the lens holding member 101 (focus lens position information) is acquired, and the position information of the lens holding member 101 is updated. At this time, the retractable lens barrel member 109 is located on the subject side.

  Next, the retractable barrel member 109 located on the subject side from the state of FIG. 4 moves to the image forming side. When the retractable lens barrel member 109 moves to the position of the lens holding member 101 in FIG. 3, the arm portion (contact portion) 109 a of the retractable lens barrel member 109 shown in FIG. Thereafter, the retractable lens barrel member 109 pushes the lens holding member 101 through the arm portion 109a, so that the lens holding member 101 and the retractable lens barrel member 109 are integrated and guided straight until the state shown in FIG. It moves along the axis 102 to the imaging side. At this time, the lens holding member 101 compresses the elastic member 112. When the elastic member 112 is not provided, the lens holding member 101 is in close contact with the nut 104, and therefore cannot move to the imaging side together with the retractable lens barrel member 109 after updating the position information of the lens holding member 101. On the other hand, in this embodiment, by providing the elastic member 112, after updating the position information of the lens holding member 101, the lens holding member 101 is moved to the imaging side together with the retractable lens barrel member 109 by the thickness of the elastic member 112. Can be moved. Further, since the lens holding member 101 is moved to the image forming side, the biasing force of the tension spring 106 is weakened, and the elastic force of the elastic member 112 is relatively strong. Therefore, the width of the elastic member 112 is sufficiently large. More preferably, the elastic member 112 is set so that the elastic force of the elastic member 112 when the lens holding member 101 is positioned on the image forming side is larger than the urging force of the tension spring 106. By doing so, the width | variety of the elastic member 112 can be fully enlarged more reliably. When the lens holding member 101 moves further from the state of FIG. 3 to the image forming side, the light shielding plate 110 does not shield the photo interrupter 108. Therefore, the output of the photo interrupter 108 is changed. By reading the change in the output (from the state where the photo interrupter 108 is shielded from being shielded), the position information of the retractable barrel member 109 (position information of the zoom lens (not shown)) is acquired. The position information of the retractable lens barrel member 109 is updated. That is, it is detected that the retractable barrel member 109 is in the retracted state.

  Therefore, with the above-described configuration, it is possible to acquire position information of the lens holding member and the retractable barrel member by using one position detection unit.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  The elastic member 112 is configured by an elastic member, springs such as a disc spring, a gel-like member having a spring property, or the like. However, the elastic member 112 is not limited to such a configuration, and any member that performs an equivalent function may be used. Further, the operation of acquiring the position information is an example, and is not limited to this configuration, and may be an operation that can acquire equivalent information.

1 Imaging device (optical equipment)
100 motor (drive means)
101 Lens holding member (holding member)
103 Lead screw 104 Nut (moving member)
108 Photointerrupter (detection unit)
109 Retractable barrel member (lens barrel member)
112 Elastic member (elastic member)
114 Photography lens (optical member)

Claims (6)

A lens barrel member movable along the optical axis;
A holding member that holds the optical member and is movable along the optical axis;
Driving means in which a lead screw parallel to the optical axis is attached to the subject side;
A moving member screwed into the lead screw and held by the holding member;
An initial position of the holding member is detected when the holding member is positioned at the first position, and the lens barrel member is detected when the holding member is positioned at a second position closer to the imaging side than the first position. A detection unit for detecting the initial position of
An elastic member that is disposed between the moving member and the holding member, and has an elastic force that widens a gap between the moving member and the holding member;
The holding device moves to the first position along with the movement of the moving member, and then moves to the second position together with the barrel member by compressing the elastic member. The holding member includes a light shielding part capable of shielding the detection part,
The detection unit detects the initial position of the holding member by the light shielding unit shielding the detection unit, and changes from a state where the light shielding unit is shielded from light to a state where the light shielding unit is not shielded from light. The optical apparatus according to claim 1, wherein an initial position of the barrel member is detected. A biasing member that biases the holding member toward the subject;
3. The optical apparatus according to claim 1, wherein an elastic force of the elastic member is larger than an urging force of the urging member when the holding member is located at the first position.   4. The optical apparatus according to claim 1, wherein an elastic force of the elastic member is greater than a weight of the optical member and the holding member.   The said holding member is provided with the position control part which controls the position in the said optical axis direction of the said holding member by contact | abutting with the said movement member, The any one of Claim 1 to 4 characterized by the above-mentioned. Lens drive mechanism. The said lens barrel member is provided with the contact part which contact | abuts to the said holding member, when the said holding member moves to the said 2nd position from the said 1st position. The optical apparatus of Claim 1.