JP2008026633A - Drive device, optical member drive device and photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device the scale increase of which is suppressed and complication of the structure of which is suppressed, which can securely avoid tooth slippage of an engaging part engaged with a screw shaft, and to provide an optical member drive device and a photographing device. <P>SOLUTION: The drive device includes a member to be guided, and a guide unit that moves the member to be guided in a predetermined guiding direction. The guide device has: the screw shaft that has a male screw formed on its periphery and extends in the predetermined guide direction; the engaging part engaged with the screw shaft; a guide member having a contact part that elastically comes into contact with the member to be guided in the guide direction; and a biasing member that biases the contact part of the guide member toward the member to be guided. When large impact is applied to the member to be guided, the impact is absorbed by the contact part and then, transmitted to the engaging part. This makes it possible to prevent tooth slippage, while restraining the drive unit from being increased in size and from being complicated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving device that moves a moving object in a predetermined direction, an optical member driving device that moves an optical member, and an imaging device that photographs a subject.

  Digital cameras and digital video cameras have been standardly equipped with an autofocus function that automatically focuses on the subject and a zoom function that realizes telephoto and wide-angle shooting. The autofocus function and zoom function are realized by moving the lens in the direction of the optical axis in the photographing device. As a driving device for moving the lens, a screw shaft with a male screw formed on the outer periphery is used as a motor. A drive device is widely used in which a moving body attached to a meshing portion that meshes with a male screw of a screw shaft is moved along the screw shaft by rotating with a screw shaft or the like. A lens holding frame or the like for holding the lens is attached to the meshing portion, and the driving device is arranged in the photographing device with the direction in which the screw shaft extends matches the optical axis direction of the lens. The holding frame moves in the optical axis direction along the screw axis.

  Here, Patent Document 1 describes a lens driving device in which a notch is provided in the meshing portion so that the meshing portion and the screw shaft are meshed with each other at half or less of the circumference of the screw shaft. In recent years, in addition to the rapid miniaturization of digital cameras and digital video cameras, small photographic devices have also been built into mobile phones and the like. Therefore, there is a problem that the lens holding frame is difficult to move smoothly. According to the lens driving device described in Patent Document 1, since the friction between the screw shaft and the meshing portion is reduced, the lens can be smoothly installed even when mounted on a small photographing device for a mobile phone. Can be driven.

  However, in a drive device that moves the lens holding frame by meshing the screw shaft and the meshing portion, if a large impact is applied to the lens holding frame when the photographing device is dropped, the load of the lens frame is applied to the meshing portion. As a result, there is a risk of tooth skipping in which the meshing portion moves from one screw shaft thread to another. If the lens is moved from the adjusted lens position, the shot image will be out of focus, or in a shooting device equipped with a sensor that detects the fall, the lens position is moved to the end of the screw shaft. Since a recovery operation such as re-controlling is performed, the subject cannot be photographed during that time, and there is a problem that a photo opportunity is missed.

In this regard, Patent Document 2 discloses a lens drive provided with a gripping force increasing mechanism that reinforces the force with which the meshing portion grips the screw shaft when a force in a direction along the screw shaft is applied to the lens holding frame. The device is described. According to the lens driving device described in Patent Document 2, when a large impact is applied to the lens holding frame, the engaging portion is tightly engaged with the screw shaft by the gripping force increasing mechanism, and tooth skipping of the engaging portion is prevented.
Japanese Patent Laid-Open No. 3-288108 JP 2004-70013 A

  However, in the drive device described in Patent Document 2, it is possible to prevent tooth skipping of the meshing portion, but it is necessary to provide a gripping force increasing mechanism in addition to the drive mechanism for driving the lens. There is a problem that it leads to an increase in size and complexity.

  The above-described problem is not limited to a driving device that moves a lens, and is generally applicable to a driving device that uses a screw shaft to move a driven body attached to a meshing portion that meshes with the screw shaft in a predetermined direction. Is.

  In view of the above circumstances, the present invention provides a driving device, an optical member driving device, and an imaging device that can suppress the increase in size and complexity of the device and prevent tooth skipping of a meshing portion that meshes with a screw shaft. Objective.

The drive device of the present invention that achieves the above object is a drive device that includes a guided member and a guide unit that moves the guided member in a predetermined guiding direction.
The above guidance unit
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion that meshes with the screw shaft; a contact member that elastically contacts the guided member in the guide direction; and a biasing member that biases the contact portion of the guide member toward the guided member. It is characterized by that.

  Conventionally, in a driving device that moves a guided member by meshing a screw shaft and a meshing portion, the guided member is directly fixed to the meshing portion, or the guided member and the meshing portion are rigid bodies (for example, metal). Therefore, the impact applied to the guided member is transmitted to the meshing portion as it is, and tooth skipping has occurred.

  In the drive device of the present invention, the contact portion is in elastic contact with the guided member, and the guided member and the meshing portion are connected via the contact portion. When a large impact is applied to the guided member, the impact is absorbed by the contact portion and then transmitted to the meshing portion. Therefore, the device can be prevented from becoming large and complicated, and tooth skipping can be prevented.

Further, an optical member driving device of the present invention that achieves the above object is an optical member driving device including a holding member that holds the optical member, and a guide unit that moves the holding member in a predetermined guiding direction.
The above guidance unit
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion meshing with a screw shaft, a contact portion that elastically contacts the optical member in the guide direction, and a biasing member that biases the contact portion of the guide member toward the optical member. It is characterized by that.

  According to the optical member driving device of the present invention, it is possible to avoid a problem that the position of the optical member is shifted due to an impact such as dropping, and it is possible to improve the reliability of the processing for driving the optical member.

In addition, an imaging apparatus of the present invention that achieves the above object includes an imaging optical system, and captures subject light that has passed through the imaging optical system to generate image data.
The photographing optical system is
An optical member driven in the optical axis direction;
A holding member for holding the optical member;
A guide unit that guides the optical member in the optical axis direction by driving the holding member in the optical axis direction;
The above guidance unit
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion meshing with a screw shaft, a contact portion that elastically contacts the optical member in the guide direction, and a biasing member that biases the contact portion of the guide member toward the optical member. It is characterized by that.

  According to the photographing apparatus of the present invention, since the trouble that the optical member moves due to an impact or the like is reduced, even when the photographing apparatus is dropped, the restoration operation for readjusting the position of the optical member is performed. Shooting can be resumed immediately without missing a photo opportunity.

  According to the present invention, it is possible to provide a driving device, an optical member driving device, and an imaging device that can suppress the increase in size and complexity of the device and can avoid tooth skipping of a meshing portion that meshes with a screw shaft.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an external perspective view of a mobile phone to which an embodiment of the present invention is applied.

  The mobile phone 100 shown in FIG. 1 is mainly equipped with a data communication function for transmitting and receiving voices and e-mails with an external device, and a photographing function for photographing a subject.

  As shown in FIG. 1 (A), a liquid crystal panel 101 on which a menu screen or a photographed image is displayed is provided on the front surface of the mobile phone 100, and a speaker (see FIG. 2) is provided inside, and sound emitted from the speaker. A mouthpiece 102 for emitting light, a first antenna 103a for transmitting and receiving data such as voice and e-mail via a base station, a selection button used as a shutter button for selecting various functions and shooting 104, a push button 105 for inputting a telephone number, a microphone (see FIG. 2) provided therein, an earpiece 106 for transmitting a voice to the microphone, a confirmation button 107 for confirming a telephone number input by the user, A second button for transmitting and receiving images, address information, etc. by wireless communication for short distance without going through the power button 108 and the base station. Antenna 109a is provided.

  Further, as shown in FIG. 1B, a photographing lens 100a for imaging subject light is embedded in the back surface of the mobile phone 100.

  When transmitting voice or e-mail using the mobile phone 100, when the user inputs a telephone number or e-mail address using the push button 105 and presses the confirm button 107, data is designated by wireless communication. Is sent to the other communication partner. Data transmitted from the mobile phone 100 is once received by the base station, and is transmitted from the base station to a communication partner via a telephone line, a LAN line, another base station, or the like. Conversely, data transmitted from a communication partner is received by the base station and converted into wireless data, and then transmitted to the mobile phone 100.

  When the user uses the cellular phone 100 to photograph a subject, when the user presses the selection button 104 with the photographing lens 100a in FIG. 1B facing the subject, the shutter built in the cellular phone 100 is turned off. Then, shooting is performed.

  Next, the internal structure of the mobile phone 100 will be described.

  FIG. 2 is an internal block diagram of the mobile phone 100.

  Inside the mobile phone 100, there are a photographing lens 100a, an iris 111, a CCD 112, an A / D (Analog / Digital) conversion unit 113, a microphone 121, a speaker 122, an interface unit 120, a first transmission / reception unit 103, an input controller 130, an image. A signal processing unit 140, a video encoder 150, an image display device 160, a second transmission / reception unit 109, a memory 170, a CPU 180, a media controller 190, various switches 181 are provided, and a recording medium 191 is further connected.

  The various switches 181 include the selection button 104 and the push button 105 shown in FIG. When these various switches 181 are pressed, the CPU 180 is informed that the switches are turned on.

  The CPU 180 transmits processing instructions to the various elements of the mobile phone 100 shown in FIG. 2 and controls the various elements. For example, when the selection button 104 in FIG. 1 is pressed in a state where a shooting mode for shooting is set, the CPU 180 gives instructions to various elements shown in FIG. 2 and starts shooting.

  First, a photographing function installed in the mobile phone 100 will be described.

  Originally, a plurality of lenses are provided in a photographing apparatus that photographs a subject, and at least one of the plurality of lenses is largely involved in focus adjustment. In FIG. A lens involved in focus adjustment among a plurality of lenses is schematically shown as a focus lens 110. The focus lens 110 is held by a lens holding frame and is moved in a direction along the optical axis by the lens driving unit 200. The photographing lens 100a corresponds to an example of a photographing optical system according to the present invention, and the focus lens 110 corresponds to an example of an optical member according to the present invention. The lens driving unit 200 will be described in detail later.

  The subject light that has passed through the photographic lens 100 a is adjusted in light quantity by the iris 111 and then imaged on the CCD 112, and the CCD 112 generates an image signal representing the subject image. The generated image signal is roughly read out by the A / D conversion unit 113, the analog signal is converted into a digital signal, and low-resolution through image data is generated. Here, a timing signal is supplied from the CPU 180 to the CCD 112, and an image signal is generated at predetermined intervals in synchronization with the timing signal. The generated through image data is sent to the image signal processing unit 140 via the input controller 130.

  The image signal processing unit 140 performs image processing such as RGB level adjustment and gamma adjustment on the through image data. The through image data after the image processing is sent to the video encoder 150 and further transmitted to the image display device 160, and the through image represented by the through image data is displayed on the liquid crystal panel 101. Here, in the CCD 112, subject light is read at every predetermined timing and an image signal is generated, so that a through image in a direction in which the photographing lens 100 a is directed is always displayed on the liquid crystal panel 101.

  The through image data generated by the A / D conversion unit 113 is also supplied to the CPU 180. Based on the through image data, the CPU 180 detects the contrast of the subject image represented by the image signal repeatedly obtained by the CCD 112 while the focus lens 110 is moved along the optical axis, and the luminance of the subject. Further, the CPU 180 controls the lens driving unit 200 attached to the focus lens 110 to move the focus lens 110 to a lens position where a contrast peak can be obtained (AF processing), and the iris according to the detected luminance. The aperture value of 111 is adjusted (AE process).

  Here, when the photographer presses the selection button 104 shown in FIG. 1 while checking the through image displayed on the liquid crystal panel 101, the CPU 180 is notified that the selection button 104 has been pressed, and is generated by the CCD 112. The image signal is finely read out by the A / D converter 113, and high-resolution captured image data is generated. The generated captured image data is sent to the image signal processing unit 140 via the input controller 130, subjected to image processing such as RGB level adjustment and gamma adjustment, and then compressed and sent to the memory 170.

  The memory 170 stores a program to be executed in the mobile phone 100, a high-speed SDRAM used as an intermediate buffer, data for various menu screens, data stored by a user, and the like. An SRAM that is a storage memory and a VRAM that stores compressed photographed image data are included. The VRAM is divided into a plurality of areas. The captured image data is stored in the plurality of areas in order, and the stored captured image data is sequentially read out to the video encoder 150 and the media controller 190.

  The video encoder 150 acquires the compressed captured image data from the memory 170 in accordance with an instruction from the CPU 180, and converts the compressed captured image data into a data format that can be displayed on the liquid crystal panel 101. The converted captured image data is sent to the image display device 130, and the captured image represented by the captured image data is displayed on the liquid crystal panel 101 by the image display device 130. In addition, when the user instructs to save the photographed image data, the media controller 190 records the compressed photographed image data stored in the memory 170 on the recording medium 191, and the user displays the photographed image data. When instructed, the media controller 190 reads out the compressed photographed image data recorded on the recording medium 191 and transmits it to the video encoder 150.

  Next, the data communication function installed in the mobile phone 100 will be described.

  When the telephone number is input using the push button 105 shown in FIG. 1 and the confirm button 107 is pressed, the telephone number is set and communication with the partner apparatus is started. At this time, communication information such as the telephone number of the mobile phone 100 and the input telephone number is transmitted from the CPU 180 to the first transmission / reception unit 103, the communication information is converted into radio waves and transmitted to the antenna 103a, and radio waves are transmitted from the antenna 103a. Be emitted. The radio wave emitted from the first antenna 103a is transmitted to the base station via a joint antenna (not shown) provided in various places such as a building and a utility pole, and the other party to which the designated telephone number is assigned by the base station. A connection with the device is established.

  When the connection with the counterpart device is established, the voice uttered by the user toward the mobile phone 100 is collected by the microphone 121, and the collected voice is converted into a radio wave representing voice data by the interface unit 120. The data is transmitted to the counterpart device by the first antenna 103 a of the transceiver 103. The radio wave received via the first antenna 103a is converted into audio data by the interface unit 120 and emitted from the speaker 122 as audio. The first transmission / reception unit 103 and the first antenna 103a transmit / receive not only voice data but also mail data representing mail using a mail address instead of a telephone number. The mail data received by the first antenna 103a and digitized by the first transmission / reception unit 103 is stored in the memory 170 by the input controller 130.

  In addition, the mobile phone 100 does not pass through the base station separately from the communication interface (the first transmitting / receiving unit 103 and the first antenna 103a) for communicating with the other device such as another mobile phone via the base station. In addition, a wireless communication interface (second transmission / reception unit 109, second antenna 109a) for performing communication by short-range wireless communication is also provided. As a communication interface for near field communication, infrared communication, Bluetooth, or the like can be applied. In the present embodiment, infrared communication is applied as a communication interface. When infrared light directly transmitted from another mobile phone or the like is received by the second antenna 109a, an electric signal based on the received infrared light is transmitted. 2 Picked up by the transmitting / receiving unit 109 and converted into digital data. Conversely, when data is transmitted to the external device, the data is transmitted to the second transmission / reception unit 109, and the data is converted into radio waves by the second transmission / reception unit 109 and emitted from the second antenna 109a.

  When infrared rays representing an image are received by the second antenna 109a, the second transmitting / receiving unit 109 converts an electrical signal based on the infrared rays into image data. The converted image data is sent to the image display device 160 and the image represented by the image data is displayed on the liquid crystal panel 101 or recorded on the recording medium 191 via the media controller 190 in the same manner as the captured image data. .

  The mobile phone 100 is basically configured as described above.

  Hereinafter, a lens driving unit 200 that is an embodiment of each of the driving device and the optical member driving device of the present invention and moves the focus lens 110 in the optical axis direction will be described.

  FIG. 3 is a schematic configuration diagram of the lens driving unit 200 shown in FIG.

  The lens driving unit 200 includes a motor 210 that rotates the screw shaft 220, a screw shaft 220 having a male screw 220a formed on the outer periphery, a lens holding frame 240 that holds the focus lens 110 shown in FIG. The guide shafts 231, 232, and 233 that guide the movement of the lens holding frame 240 in the optical axis direction, and a spring 260 that biases the carrier 250 toward the lens holding frame 240. Is provided. The lens holding frame 240 corresponds to an example of the guided member and the holding member according to the present invention, and the combination of the motor 210, the screw shaft 220, the guide shafts 231, 232, 233, the carrier 250, and the spring 260 is as follows. It corresponds to an example of a guide unit according to the present invention. The screw shaft 220 corresponds to an example of a screw shaft according to the present invention, the carrier 250 corresponds to an example of a guide member according to the present invention, and the spring 260 corresponds to an example of an urging member according to the present invention.

  Next, the configurations of the carrier 250 and the lens holding frame 240 will be described.

  FIG. 4 is a perspective view of the carrier 250.

  The carrier 250 includes a mesh portion 251 provided with a screw thread 251 a that meshes with the male screw 220 a of the screw shaft 220, a guide shaft penetration portion 254 through which the guide shaft 233 passes, and a mesh portion 251 that extends from the guide shaft penetration portion 254. The upper arm 252 and the lower arm 253 urge the screw shaft 220 toward the meshing portion 251 with the screw shaft 220 interposed therebetween. The upper arm 252 has a tip 252a in contact with the lens holding frame 240, and the lower arm 253 has one end of a spring 260 attached to the tip 252a. The upper arm portion 252 and the lower arm portion 253 have elasticity by extending in an elongated shape, and are deformed when a force is applied, and then return to the original shape. The meshing part 251 corresponds to an example of the meshing part according to the present invention, and the upper arm part 252 corresponds to an example of the contact part according to the present invention.

  5 is a perspective view of the lens driving unit 200 shown in FIG. 3 when viewed from the side where the spring 260 is attached. FIG. 6 is a perspective view of the lens driving unit 200 when viewed from the side where the spring 260 is attached. FIG.

  The lens holding frame 240 includes a holding portion 242 that holds the focus lens 110 and a support portion 241 that is guided by the guide shaft 231 and supported by the carrier 250. The support portion 241 is provided with a protrusion 240a to which the spring 260 is connected.

  As shown in FIG. 5, the carrier 250 is moved along the guide shaft 233 when the screw shaft 220 is rotated by the motor 210 because the screw thread 251a of the meshing portion 251 meshes with the male screw 220a of the screw shaft 220. The

  Further, as shown in FIG. 6, one end of the spring 260 is attached to the lower arm 253 of the carrier 250 and the other end is attached to the protrusion 240a of the lens holding frame 240, whereby the carrier 250 and the lens holding frame 240 are connected. The carrier 250 is biased toward the lens holding frame 240 by a spring 260.

  FIG. 7 is a schematic enlarged view of the vicinity of the carrier 250 and the lens holding frame 240.

  In FIG. 7, for convenience of explanation, unnecessary elements are not shown, and the arrangement and configuration features of each element are emphasized considerably more than actual.

  As shown in FIG. 7A, in the carrier 250, the engaging portion 251 is engaged with the screw shaft 220, and the tip 252a of the upper arm portion 252 is pressed against the support portion 241 of the lens holding frame 240 by the spring 260. . For example, when the screw shaft 220 rotates and the carrier 250 moves upward in the drawing along the guide shaft 233, the tip 252 a of the upper arm 252 pushes up the support portion 241, and the lens holding frame 240 moves along the guide shaft 231. Moved upwards.

  Here, the cellular phone 100 on which the lens driving unit 200 is mounted is inferior in gripping property due to its small size, and is easily dropped. When the mobile phone 100 falls, a large impact is applied to the lens holding frame 240 and the load of the lens holding frame 240 is applied to the carrier 250.

  In the present embodiment, for example, when a large impact force is applied to the lens holding frame 240 in the downward direction in the figure, a load is transmitted from the lens holding frame 240 to the upper arm portion 252 of the carrier 250 as shown in FIG. The Since the upper arm portion 252 has elasticity, the upper arm portion 252 is deformed when receiving an impact force from the lens holding frame 240 and is transmitted to the meshing portion 251 after the impact force is relaxed. For this reason, the malfunction that a big force is added to the meshing part 251 and a tooth skip arises can be avoided.

  When the screw shaft 220 is rotated and the carrier 250 is moved upward from the state shown in FIG. 7B, the deformed upper arm 252 pushes up the lens holding frame 240 and returns to its original shape. The lens is driven.

  As described above, according to the lens driving unit 200 of the present embodiment, tooth skipping of the carrier 250 due to a drop impact or the like can be prevented, and reliability in lens driving can be improved.

  Here, in the above description, the example in which the carrier moving in the optical axis direction along the screw shaft is applied as the meshing portion that meshes with the male screw of the screw shaft, but the meshing portion referred to in the present invention is a nut or the like. Also good.

  In the above description, the drive device that moves the lens in the optical axis direction has been described. However, the drive device of the present invention may move an object other than the lens.

  In the above description, an example in which the imaging device of the present invention is applied to a mobile phone has been described.

  In the above description, a CCD is shown as an example of the image sensor, but the image sensor used in the photographing apparatus of the present invention may be a CMOS sensor or the like.

1 is an external perspective view of a mobile phone to which an embodiment of the present invention is applied. It is an internal block diagram of a mobile phone. It is a schematic block diagram of the lens drive unit shown in FIG. It is a perspective view of a carrier. It is a perspective view when the lens drive unit shown in FIG. 3 is seen from the side where the spring is attached. It is a front view when a lens drive unit is seen from the side where the spring was attached. FIG. 4 is a schematic enlarged view of the vicinity of a carrier and a lens holding frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Mobile phone 100a Shooting lens 101 Liquid crystal panel 102 Mouthpiece 103 1st transmission / reception part 103a 1st antenna 104 Selection button 105 Push button 106 Earpiece 107 Confirmation button 108 Power button 109 2nd transmission / reception part 109a 2nd antenna 110 Focus lens 111 Iris 112 CCD
113 A / D conversion unit 120 Interface unit 121 Microphone 122 Speaker 130 Input controller 140 Image signal processing unit 150 Video encoder 160 Image display device 170 Memory 180 CPU
181 Various switches 190 Media controller 190a Recording medium 200 Lens drive unit 210 Motor 220 Screw shaft 220a Male screw 231, 232, 233 Guide shaft 240 Lens holding frame 250 Carrier 251 Engagement portion 252 Upper arm portion 253 Lower arm portion 254 Guide shaft penetration portion 251a Screw Mountain 260 spring

Claims (3)

In a drive device comprising a guided member and a guide unit for moving the guided member in a predetermined guiding direction,
The guide unit is
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion meshing with the screw shaft, a contact portion elastically contacting the guided member in the guiding direction, and urging the contact portion of the guiding member toward the guided member A drive device comprising an urging member. In an optical member driving device comprising a holding member that holds an optical member, and a guide unit that moves the holding member in a predetermined guide direction,
The guide unit is
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion that meshes with the screw shaft, a contact portion that elastically contacts the optical member in the guide direction, and a bias that biases the contact portion of the guide member toward the optical member An optical member driving device comprising a member. In an imaging device that includes an imaging optical system and generates image data by capturing subject light that has passed through the imaging optical system,
The photographing optical system is
An optical member driven in the optical axis direction;
A holding member for holding the optical member;
A guide unit that guides the optical member in the optical axis direction by driving the holding member in the optical axis direction;
The guide unit is
A rotatable screw shaft having a male screw formed on the outer periphery and extending in a predetermined guide direction,
A guide member having a meshing portion that meshes with the screw shaft, a contact portion that elastically contacts the optical member in the guide direction, and a bias that biases the contact portion of the guide member toward the optical member An imaging apparatus comprising a member.

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