JPH0511115U - Movable optical system moving device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] In a still camera, a video camera, etc., to move the movable optical system of the lens barrel accurately in order to improve the accuracy of focusing and zooming. A movable optical system moving device that moves a movable optical system holding member 4 in parallel with an optical axis by advancing and retracting the nut portion 2 in parallel with the screw shaft 1 as the screw shaft 1 rotates is provided. An elastic portion 3 for pressing the screw shaft 1 side is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention is a lens mirror used in optical equipment such as still cameras and video cameras. The movable optical system moving device that moves the movable optical system along the optical axis in the barrel To do.

[0002]

[Prior art]

  In the lens barrel, the movable optical system is used for focusing and zooming. As a mechanism to move the optical axis back and forth, a screw and nut combination has been used in the past. Is known, which is advantageous for converting the rotational displacement of a motor into a linear displacement. Therefore, it is widely adopted. Especially in combination with a stepping motor Therefore, this advantage is more exerted. That is, if the thread is single, the screen Set the amount of advance / retreat of the nut as the nut will advance / retreat by one pitch for one rotation. It will be easy.

[0003]   On the other hand, when applying such a movable optical system moving device to various cameras, , Move the movable optical system quickly and accurately to stop it at the proper position. Since it is necessary to have a device that can The screwing is required to be proper. However, the thread of the screw and the nut There are two contradictory problems in screwing with the threaded portion. That is, screw If the clearance, which is a clearance, is larger than the appropriate amount, play between the two is called To stop the movable optical system as the feed error increases. Is not accurate, and if the clearance is smaller than the proper amount, it will And the load due to screwing becomes large, which is disadvantageous when moving the movable optical system quickly. That is the point. Therefore, proper screwing can be obtained in consideration of this point. It is required to process the parts as follows.

[0004]

[Problems to be solved by the device]   However, processing the threaded portion in response to such demands increases the processing time. This will increase the cost of longevity. In addition, as in recent years, when materials such as resin are used, In this case, even if it is properly processed during manufacturing, depending on the ambient temperature during use, Initial screwability changes.

[0005]   The present invention has been made in view of such problems, and its purpose is to The roller is suitable for materials such as resin without increasing the processing cost. It is possible to move the movable optical system quickly and accurately to stop it at an appropriate position. It is an object of the present invention to provide a movable optical system moving device.

[0006]

[Means for Solving the Problems]

  In order to achieve the above object, the movable optical system moving device of the present invention comprises a rotary drive device. Transmission of rotation to the rotation of the screw shaft, which is linked to this device and has a threaded portion. Then, as the screw shaft rotates, the nut part that screws with the screw part of the screw shaft By converting and transmitting linear motion that moves forward or backward parallel to the screw axis, A movable optical system with a nut, or a movable optical system holding the movable optical system In the movable optical system moving device that moves the member parallel to the optical axis, An elastic portion that presses toward the axle side is provided.

[0007]   As a further means, a movable optical system or a movable optical system holding member, and The elastic portion and the elastic portion are integrally formed of a resin material. A hollow part is formed so that it is in the same direction as the axial direction, and the thin part enables elastic displacement. To do. In addition, if necessary, the nut part may be a half-circle screw or a nut. The guide part or the movable optical system is slidably supported by the guide member indicating the reference position. It is a scam.

[0008]

[Action]

  With the above configuration, the nut part is always pressed against the screw shaft by the action of the elastic part. Therefore, due to changes in the environment during design, manufacturing, or use. Play (play) that occurs slightly in the hem is absorbed. Also, the following displacement characteristics of the elastic part Depending on the quality, the nut part moves smoothly following the rotation of the screw shaft. As a result, the load on the screw shaft is small and the driving force of the motor is small. further The vibration of the motor etc. that has propagated to the screw shaft is absorbed by the elastic part Vibration is not transmitted to the optical system.

[0009]

【Example】

  Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. Fig. 1 is an actual example of the present invention It is a perspective view of the movable optical system moving device concerning an example. The screw shaft 1 has a thread Has been formed. The nut portion 2 has a threaded portion that engages with the threaded portion of the screw shaft 1. Movable for holding the elastic part 3 and a movable optical system (not shown) The optical system holding member 4 is integrally formed of a resin material. Also movable optics The movable optical system holding member 4 for holding the system or the movable optical system is guided by the guide pole 5. You are guided in the direction of movement. FIG. 2 shows a movable optical system moving device according to an embodiment of the present invention. FIG. The screw shaft 1 is connected to a stepping motor 6, The rotation drive of the stepping motor 6 is transmitted to the screw shaft 1. It The screw shaft 1 and the guide pole 5 are arranged on a fixing member 7 such as a lens barrel. ing.

[0010]   To move the movable optical system inside the lens barrel, rotate the stepping motor 6. It is driven and transmitted to the screw shaft 1 to rotationally displace the screw shaft 1 and The nut part 2 is screwed into place by screwing the screw part of the screw shaft 1 and the screw part of the nut part 2 together. And to convert it into a linear displacement of the movable optical system holding member 4 formed integrally with resin. Therefore, it is done.

[0011]   Here, when the screw shaft 1 and the nut portion 2 are screwed together, play ( Even if there is backlash, the nut portion is acted by the elastic property of the thin portion 3a of the elastic portion 3. No. 2 is always pressed against the screw shaft 1 side, so play (play) is absorbed. Therefore, the continuous rotational displacement of the screw shaft 1 is accurately transmitted to the nut portion 2.   Also, due to the action of the follow-up displacement property of the thin portion 3a of the elastic portion 3, the nut portion 2 has a Since the pressure contact force to the clew shaft 1 does not become larger than necessary and is kept in an appropriate state, Since the nut part smoothly follows the rotation of the screw shaft, it moves due to screwing. Since the load on the clew shaft is small and the motor drive force is small, quick drive is possible. It will be possible.

[0012]

[Effect of device]

  As described above, the movable optical system moving device according to the present invention rotates the rotation drive device Converts and transmits the rotation of the screw shaft that is linked to this device and has a threaded portion. , Screw the nut that engages with the screw of the screw shaft as the screw shaft rotates. By converting and transmitting linear motion that moves forward or backward in the axial direction of the Liu shaft , A movable optical system having a nut portion or a movable optical system holding portion for holding the movable optical system In the movable optical system moving device that moves the material along the optical axis, the nut part Since the elastic part that presses the screw shaft side is provided, the nut part Since it is always pressed against the screw shaft by the action of the Even if there is (play), this play (play) is absorbed, and the elastic part follows the displacement characteristic. Not only does the nut move smoothly following the rotation of the screw shaft, The load on the motor is also reduced and quick drive is possible. It also propagates to the screw shaft The vibration of the motor, etc. is absorbed by the elastic part and is transmitted to the movable optical system. Absent. Furthermore, the movable optical system or the movable optical system holding member, the nut portion, and the elastic portion Is integrally formed of a resin material, heat generated by the ambient temperature during use after manufacturing The effect that the contraction is also absorbed by the action of the elastic portion is obtained. Moreover, resin material Since it is formed integrally with the material, it has excellent workability.

[Brief description of drawings]

FIG. 1 is a perspective view of a movable optical system moving device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a movable optical system moving device according to an embodiment of the present invention.

[Explanation of symbols]

1 screw shaft 2 Nut part 3 elastic part 4 Movable optical system holding member 5 Guide pole 6 stepping motor 7 fixing member

Claims (4)

[Scope of utility model registration request] 1. A nut portion that transmits the rotation of a rotary drive force source to the rotation of a screw shaft that is linked to the rotary drive force source and that has a screw portion, and that is screwed with the screw portion of the screw shaft. A movable optical system for moving a movable optical system having the nut portion or a movable optical system holding member for holding the movable optical system in parallel with the optical axis by converting and transmitting the linear movement to advance and retreat in parallel with the screw axis. In the moving device, a movable optical system moving device is provided with an elastic portion that presses the nut portion toward the screw shaft side. 2. The movable optical system or the movable optical system holding member, the nut portion, and the elastic portion are integrally formed of a resin material, and the elastic portion has a center line in the same direction as the screw axial direction. 2. The movable optical system moving device according to claim 1, wherein a hollow portion is formed in the hollow portion, and the thin portion allows elastic displacement. 3. The movable optical system moving device according to claim 1, wherein the nut portion is a half-circle screw. 4. The movable optical system moving device according to claim 1, wherein the nut portion or the movable optical system is slidably supported by a guide member indicating a reference position.