JP2007139862A - Lens driving mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens driving mechanism having compact and simple constitution. <P>SOLUTION: The lens driving mechanism 100 has a lens 120 moving along an optical axis A-A and a lens frame 130 holding the lens 120, a polymer actuator 150 moving the lens frame 130, and lens barrels 140 and 141 supporting the lens frame 130 and the polymer actuator 150. The polymer actuator 150 is composed of polymer material arranged perpendicularly to the optical axis A-A, and has hollow circular shape and further has a tongue-like piece 151 formed along its circumferential direction. By deforming the tongue-like piece 151 of the polymer actuator 150, the lens frame 130 is moved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens driving mechanism.

  An imaging module mounted on an imaging device typified by a mobile phone with an imaging function or a digital camera is required to be further reduced in size, function, and definition. For this reason, the lens drive mechanism associated with the focusing function and zoom function is also required to be further downsized and highly functional.

  Conventionally, an electromagnetic actuator such as a voice coil motor or an electrostrictive element such as a piezo element is used for a small lens driving mechanism. Further, in recent years, a lens driving mechanism adapted to a polymer actuator using a polymer material has been researched and developed. For example, Patent Document 1 discloses a lens driving mechanism that drives a lens using a polymer actuator formed in an annular shape.

JP 2005-168088 A

  However, in the configuration of the prior art, the width in the radial direction of the polymer actuator formed in an annular shape is narrowed by downsizing the imaging module. For this reason, since the amount of distortion is reduced, there arises a problem that a sufficient stroke for driving the lens cannot be obtained. In addition, as a solution, a configuration is also disclosed in which a stroke necessary for lens driving is obtained by stacking polymer actuators. However, this configuration complicates the lens driving mechanism. For this reason, manufacture of a lens drive mechanism may become more complicated.

  The present invention has been made in view of the above, and an object thereof is to provide a lens driving mechanism having a small and simple configuration.

  In order to solve the above-described problems and achieve the object, the present invention supports a lens that moves along an optical axis, a lens frame that holds the lens, an actuator that moves the lens frame, and the lens frame and the actuator. A lens driving mechanism, and the actuator is a polymer actuator made of a polymer material arranged perpendicular to the optical axis, and the polymer actuator has a hollow circular shape and has a high It is possible to provide a lens driving mechanism that further includes a tongue piece formed along the circumferential direction of the molecular actuator and moves the lens frame when the tongue piece of the polymer actuator is deformed.

  According to a preferred aspect of the present invention, it is desirable that a plurality of tongue pieces of the polymer actuator are formed for one polymer actuator.

  According to a preferred aspect of the present invention, it is desirable that the tongue pieces of the polymer actuator have the same shape and are formed at three or more positions in axial symmetry with respect to the optical axis.

  According to a preferred aspect of the present invention, the contact portion of the lens barrel with the polymer actuator is formed of a conductive material, and the lens barrel is used at a site different from the site where the tongue of the polymer actuator is formed. It is desirable to fix the polymer actuator and supply power to the polymer actuator via the lens barrel.

  According to a preferred aspect of the present invention, the contact portion of the lens frame with the polymer actuator is formed of a conductive material, a part of the lens barrel is formed of a non-conductive material, and the tongue of the polymer actuator is It is desirable to fix the polymer actuator using a lens barrel at a part different from the formed part and to supply power to the polymer actuator via the lens frame.

  According to a preferred aspect of the present invention, it is desirable to fix the tip of the tongue piece of the polymer actuator to the lens frame and move the lens frame by deformation of the tongue piece of the polymer actuator.

  Further, according to a preferred aspect of the present invention, the elastic member is provided on the side opposite to the side on which the polymer actuator is disposed with respect to the lens frame, and the force and deformation of the tongue of the polymer actuator are restored. It is desirable to move the lens frame in two directions by force.

Moreover, according to the preferable aspect of this invention, it comprises two polymer actuators,
Each polymer actuator is disposed at a position facing each other across the lens frame, and the lens frame is formed by complementarily deforming the tongue piece of one polymer actuator and the tongue piece of the other polymer actuator, respectively. It is desirable to move in two directions.

  In addition, according to the present invention, there is provided a lens driving mechanism including a lens that moves along the optical axis, a lens frame that holds the lens, an actuator that moves the lens frame, and a lens frame and a lens barrel that supports the actuator. The actuator is a polymer actuator made of a polymer material arranged on the surface of the lens barrel perpendicular to the optical axis, and the plurality of polymer actuators are respectively formed along the openings. It is possible to provide a lens driving mechanism having a deforming portion and moving the lens frame when the deforming portion of the polymer actuator is deformed.

  According to the present invention, it is possible to provide a lens driving mechanism having a small and simple configuration.

  Hereinafter, embodiments of a lens driving mechanism according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  A configuration of the lens driving mechanism 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows a perspective cross-sectional configuration of a lens driving mechanism 100 according to the present embodiment. As shown in FIG. 1, the lens driving mechanism 100 includes a lens 120, a lens frame 130 that holds the lens 120, a first mirror that supports the lens frame 130 and is slidable in the direction of the optical axis AA. From the tube 140, the polymer actuator 150 made of a polymer material arranged perpendicular to the optical axis AA, and the second lens barrel 141 that fixes the polymer actuator 150 together with the first lens barrel 140. It is configured.

  Each component other than the lens 120 has a substantially hollow cylindrical shape. A light ray incident on the lens driving mechanism 100 from the outside travels along the optical axis AA, passes through the lens 120, and receives a necessary optical action.

  FIG. 2 shows the top structure of the polymer actuator 150. As shown in FIG. 2, the polymer actuator 150 is formed in a hollow circular shape. Then, along the circumferential direction, three tongue pieces 151 having the same shape are formed symmetrically with respect to the central axis. It is desirable that the central axis and the optical axis AA in FIG.

  Both surfaces of the outermost peripheral portion 152 of the polymer actuator 150 are fixed by the first lens barrel 140 and the second lens barrel 141. The tip of the tongue 151 of the polymer actuator 150 is fixed to the lower surface of the lens frame 130.

  Next, the operation of the polymer actuator 150 according to this embodiment will be described with reference to FIGS. 3 and 4 schematically show the side structure of the polymer actuator 150 and the connection of the drive power supply. In this embodiment, an explanation will be given using a polymer actuator containing an ionic fluid in an ion exchange resin and gold plating on the front and back surfaces as the polymer actuator.

  Next, the driving principle of the polymer actuator 150 will be described. In the polymer actuator 150, electrodes are formed on the front and back surfaces of the ion exchange resin by gold plating, respectively. A drive power supply 160 is connected between both electrodes to apply a voltage. Thereby, movement of a cation occurs in the ion exchange resin according to the applied voltage, and water molecules that are polar molecules move according to the movement of the cation. Cations and water molecules move to the negative electrode side. For this reason, a swelling difference arises on the front and back surfaces of the ion exchange resin. The negative electrode side is rich in cations and water molecules. On the other hand, cations and water molecules are depleted on the positive electrode side. Due to this difference in swelling, the ion exchange resin is deformed by extending to the negative electrode side and contracting to the positive electrode side.

  Therefore, as shown in FIG. 3, a positive voltage is applied to the upper surface side electrode in the drawing and a negative voltage is applied to the lower surface side electrode in the drawing with respect to the polymer actuator 150 by the driving power supply 160. At this time, the polymer actuator 150 is deformed so as to bend toward the electrode to which a positive voltage is applied. Although not shown, the outermost peripheral portion 152 of the polymer actuator 150 in FIG. 2 is fixed by the first lens frame 140 and the second lens frame 141. As a result, the tongue 151 of the polymer actuator 150 is deformed so as to rise upward in FIG.

  On the other hand, as shown in FIG. 4, a negative voltage is applied to the upper surface side electrode in the drawing and a positive voltage is applied to the lower surface side electrode in the drawing with respect to the polymer actuator 150 by the driving power supply 160. As a result, the tongue piece 151 of the polymer actuator 150 is deformed so as to stand downward in FIG.

  Next, the operation of the lens driving mechanism 100 according to the present embodiment will be described with reference to FIGS. 5 and 6 schematically show the cross-sectional configuration of the lens driving mechanism 100 and the connection of the driving power source. In the lens driving mechanism 100 shown in FIG. 5, the first lens barrel 140 and the second lens barrel 141 are formed of conductive members.

  As shown in FIG. 5, a positive voltage is applied to the first lens barrel 140 by the driving power supply 160. Then, a positive voltage is applied to the upper surface side electrode in the drawing of the polymer actuator 150 through the first lens barrel 140.

  Further, a negative voltage is applied to the second lens barrel 141. Then, a negative voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141. As described above, by applying a drive voltage to the polymer actuator 150, the tongue 151 of the polymer actuator 150 is deformed upward in FIG. Thereby, the lens frame 130 can be moved upward in FIG.

  On the other hand, as shown in FIG. 6, a negative voltage is applied to the first lens barrel 140 by the driving power supply 160. Then, a negative voltage is applied to the upper surface side electrode in the drawing of the polymer actuator 150 through the first lens barrel 140. Further, a positive voltage is applied to the second lens barrel 141. Then, a positive voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141. By applying a driving voltage to the polymer actuator 150 as described above, the tongue 151 of the polymer actuator 150 is deformed downward in FIG. Thereby, the lens frame 130 can be moved downward in FIG.

  Here, when the lens frame 130 is moved downward in the figure, the same effect can be obtained by short-circuiting the first lens barrel 140 and the second lens barrel 141. However, the configuration in which the power supply 160 is connected as shown in FIG. 6 can move the lens frame 130 at a higher speed, can prevent the lens frame 130 from moving due to gravity, and has a neutral point for driving the polymer actuator 150. Advantages such as being able to hold can be obtained.

  7 and 8 show modifications of the polymer actuator 150 and the tongue piece 151, respectively. As described above, by controlling the voltage applied to the polymer actuator 150, the lens 120 can be moved along the optical axis AA. By moving the lens 120, optical effects such as focusing and zooming can be realized.

  Further, by adopting the configuration as shown in FIGS. 1 to 6 as the lens driving mechanism, the length that the polymer actuator 150 is deformed despite the lens driving mechanism having a small diameter by downsizing the imaging module. The length of the tongue piece 151 can be made relatively long. For this reason, it becomes possible to take a sufficiently large stroke of movement of the lens 120.

  Further, the tongue pieces 151 are formed in three places having the same shape and symmetrical with respect to the central axis. For this reason, it is possible to prevent the lens frame 130 from being inclined and caught on the lens frame. As a result, the lens 120 can be driven more stably. In addition, power can be supplied to the polymer actuator 150 with a very simple configuration.

  Next, the configuration of the lens driving mechanism 200 according to the second embodiment of the present invention will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. 9 and 10 show a cross-sectional configuration of the lens driving mechanism 200 according to the present embodiment. As shown in FIG. 9, the lens driving mechanism 200 supports the lens 120, the lens frame 130 that holds the lens 120, and the lens frame 130, and is slidable in the direction of the optical axis AA. , A polymer actuator 150 made of a polymer material arranged perpendicular to the optical axis A-A, a second barrel 141 that fixes the polymer actuator 150 together with the barrel 140, and a lens 140 It comprises a spring member 170 that pressurizes the frame 130 toward the polymer actuator 150 side.

  In the present embodiment, the tip of the tongue piece 151 of the polymer actuator 150 does not need to be fixed to the lens frame 130. Each component other than the lens 120 has a substantially hollow cylindrical shape, and light from the outside world passes through the lens 120 along the optical axis A-A and receives a necessary optical action.

  Next, the operation of the lens driving mechanism 200 according to the present embodiment will be described with reference to FIGS. 9 and 10 schematically show the cross-sectional configuration of the lens driving mechanism 200 and the connection of the driving power supply 160.

  In the lens driving mechanism 200 shown in FIGS. 9 and 10, the first lens barrel 140 and the second lens barrel 141 are formed of a conductive member. As shown in FIG. 9, a positive voltage is applied to the first lens barrel 140 by the driving power supply 160. Then, a positive voltage is applied to the upper surface side electrode in the drawing of the polymer actuator 150 through the first lens barrel 140.

  Further, a negative voltage is applied to the second lens barrel 141. Then, a negative voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141. As described above, by applying a driving voltage to the polymer actuator 150, the tongue 151 of the polymer actuator 150 is deformed upward in FIG. The spring constant of the spring member 170 is appropriately set so that the driving force due to the deformation of the tongue 151 of the polymer actuator 150 exceeds the restoring force of the spring member 170. As a result, the lens frame 130 moves upward in FIG. In the case of an elastic member, a rubber member or the like can be used instead of the spring member 170.

  On the other hand, as shown in FIG. 10, a negative voltage is applied to the first lens barrel 140 by the drive power supply 160. Then, a negative voltage is applied to the upper surface side electrode in the drawing of the polymer actuator 150 through the first lens barrel 140. Further, a positive voltage is applied to the second lens barrel 141. Then, a positive voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141.

  A drive voltage is applied to the polymer actuator 150 as described above. Thereby, the tongue piece 151 of the polymer actuator 150 is deformed downward in FIG. Then, the lens frame 130 moves downward in FIG. 10 by the restoring force of the spring member 170.

  Here, when the lens frame 130 is moved downward in FIG. 10, the same effect can be obtained by short-circuiting the first lens barrel 140 and the second lens barrel 141. However, the configuration in which the power supply 160 is connected as shown in FIG. 10 can provide advantages such as being able to move the lens frame 130 at high speed and maintaining a neutral point for driving the polymer actuator 150.

  As described above, by controlling the voltage applied to the polymer actuator 150, the lens 120 can be moved along the optical axis AA. As a result, optical effects such as focusing and zooming can be realized.

  Further, by adopting the configuration as shown in FIGS. 9 and 10 as the lens driving mechanism, the length by which the polymer actuator 150 is deformed despite the lens driving mechanism having a small diameter by downsizing the imaging module. The length of the tongue piece 151 can be made relatively long. For this reason, it becomes possible to take a sufficiently large stroke of movement of the lens 120.

  Further, the tongue pieces 151 are formed in three places having the same shape and symmetrical with respect to the central axis. For this reason, it is possible to prevent the lens frame 130 from being inclined and caught on the lens frame. As a result, the lens 120 can be driven more stably. In addition, power can be supplied to the polymer actuator 150 with a very simple configuration.

  Further, it is not necessary to bond the tongue 151 of the polymer actuator 150 and the lens frame 130. For this reason, slip occurs at both contact points. Therefore, the lens 120 can be driven more smoothly.

  Next, the configuration of the lens driving mechanism 300 according to the third embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part same as Example 1, and the overlapping description is abbreviate | omitted. 11 and 12 each show a cross-sectional configuration of the lens driving mechanism 300 according to the present embodiment.

  As shown in FIGS. 11 and 12, the lens driving mechanism 300 supports the lens 120, the lens frame 130 holding the lens 120, and the lens frame 130, and is slidable in the direction of the optical axis AA. One lens barrel 140, a polymer actuator 150 made of a polymer material arranged perpendicular to the optical axis AA, a second lens barrel 141 that fixes the polymer actuator 150 together with the lens barrel 140, The lens barrel 140 includes a third lens barrel 142 that holds the spring member 170 together with the lens barrel 140, and a spring member 170 that pressurizes the lens frame 130 toward the polymer actuator 150 side. In the present embodiment, the tip of the tongue piece 151 of the polymer actuator 150 does not need to be fixed to the lens frame 130.

  Each component other than the lens 120 has a substantially hollow cylindrical shape. As a result, light rays from the outside world pass through the lens 120 along the optical axis A-A and are subjected to the necessary optical action.

  Next, the operation of the lens driving mechanism 300 according to this embodiment will be described with reference to FIGS. 11 and 12 schematically show the cross-sectional configuration of the lens driving mechanism 300 and the connection of the driving power supply 160.

  In the lens driving mechanism 300 shown in FIGS. 11 and 12, the second lens barrel 141, the third lens barrel 142, the spring member 170, and the lens frame 130 are each formed of a conductive member. In contrast, the first lens barrel 140 is formed of a non-conductive member.

  As shown in FIG. 11, a positive voltage is applied to the third lens barrel 142 by the driving power supply 160. Then, a positive voltage is applied to the upper electrode in the drawing of the polymer actuator 150 through the third barrel 142, the spring member 170, and the lens frame 130.

  Further, a negative voltage is applied to the second lens barrel 141. Then, a negative voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141. By applying a driving voltage to the polymer actuator 150 as described above, the tongue 151 of the polymer actuator 150 is deformed upward in the drawing. The spring constant of the spring member 170 is appropriately set so that the driving force due to the deformation of the polymer actuator 150 exceeds the restoring force of the spring member 170. As a result, the lens frame 130 moves upward in FIG.

  On the other hand, as shown in FIG. 12, a negative voltage is applied to the third lens barrel 142 by the drive power supply 160. Then, a negative voltage is applied to the upper electrode in the drawing of the polymer actuator 150 through the third lens barrel 142, the spring member 170, and the lens frame 130. Further, a positive voltage is applied to the second lens barrel 141. Then, a positive voltage is applied to the lower surface side electrode in the drawing of the polymer actuator 150 via the second lens barrel 141.

  By applying a driving voltage to the polymer actuator 150 as described above, the tongue 151 of the polymer actuator 150 is deformed downward in FIG. For this reason, the lens frame 130 moves downward in FIG. 12 by the restoring force of the spring member 170.

  Here, when the lens frame 130 is moved downward in the figure, the same effect can be obtained by short-circuiting the second lens barrel 141 and the third lens barrel 142. However, the configuration in which the power supply 160 is connected as shown in FIG. 12 can often obtain advantages such as being able to move the lens frame 130 at a high speed and maintaining a neutral point for driving the polymer actuator 150.

  As described above, by controlling the voltage applied to the polymer actuator 150, the lens 120 can be moved along the optical axis AA. As a result, optical effects such as focusing and zooming can be realized.

  Further, by adopting the configuration as shown in FIGS. 11 and 12 as the lens driving mechanism, the length that the polymer actuator 150 is deformed despite the lens driving mechanism having a small diameter by downsizing the imaging module. The length of the tongue piece 151 can be made relatively long. For this reason, it becomes possible to take a sufficiently large stroke of movement of the lens 120.

  Further, the tongue pieces 151 are formed in three places having the same shape and symmetrical with respect to the central axis. For this reason, it is possible to prevent the lens frame 130 from being inclined and caught on the lens frame. As a result, the lens 120 can be driven more stably. In addition, it is possible to supply power to the polymer actuator with a very simple configuration.

  Further, it is not necessary to bond the tongue 151 of the polymer actuator 150 and the lens frame 130. For this reason, slip occurs at both contact points. Therefore, the lens 120 can be driven more smoothly.

  In the present embodiment, the first lens barrel 140 occupying most of the surface of the lens driving mechanism 300 is formed of a non-conductive member. For this reason, when installing the lens drive mechanism 300 in an imaging module, it can be electrically insulated from other components. As a result, the lens driving mechanism 300 can be easily installed.

Next, the configuration of the lens driving mechanism 400 according to the fourth embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part same as Example 1, and the overlapping description is abbreviate | omitted.
13 and 14 show cross-sectional configurations of the lens driving mechanism 400 according to the present embodiment, respectively.

  As shown in FIGS. 13 and 14, the lens driving mechanism 400 supports the lens 120, the lens frame 130 holding the lens 120, the lens frame 130, and is slidable in the direction of the optical axis AA. A first barrel 140, a first polymer actuator 150 and a second polymer actuator 153 made of a polymer material arranged perpendicular to the optical axis AA, and a first height together with the barrel 140. It consists of a second lens barrel 141 for fixing the molecular actuator 150 and a third lens tube 142 for fixing the second polymer actuator 153 together with the lens barrel 140. In this embodiment, it is not necessary to fix the tips of the tongue piece 151 of the first polymer actuator 150 and the tongue piece 154 of the second polymer actuator 153 to the lens frame 130.

  Each component other than the lens 120 has a substantially hollow cylindrical shape. As a result, light rays from the outside world pass through the lens 120 along the optical axis A-A and are subjected to the necessary optical action.

  Next, the operation of the lens driving mechanism 400 according to the present embodiment will be described with reference to FIGS. 13 and 14 schematically show the cross-sectional configuration of the lens driving mechanism 400 and the connection of the driving power supply.

  In the lens driving mechanism 400 shown in FIGS. 13 and 14, the first lens barrel 140, the second lens barrel 141, and the third lens barrel 142 are formed of conductive members. As shown in FIG. 13, a positive voltage is applied to the first lens barrel 140 by the driving power supply 160. Then, a positive voltage is applied to the upper surface side electrode of the first polymer actuator 150 through the first lens barrel 140. Further, a negative voltage is applied to the second lens barrel 141. Then, a negative voltage is applied to the lower surface side electrode in the drawing of the first polymer actuator 150 via the second lens barrel 141.

  Further, a positive voltage is applied to the third lens barrel 142 by the driving power supply 161. Then, a positive voltage is applied to the upper surface side electrode in the drawing of the second polymer actuator 153 via the third lens barrel 142. Further, a negative voltage is applied to the first lens barrel 140. Then, a negative voltage is applied to the lower electrode in the drawing of the second polymer actuator 153 via the first lens barrel 140.

  As described above, by applying a driving voltage to the first polymer actuator 150 and the second polymer actuator 153, the tongue piece 151 of the first polymer actuator 150 and the tongue piece of the second polymer actuator 153 are applied. 154 is deformed upward in FIG. As a result, the lens frame 130 moves upward in FIG.

  On the other hand, as shown in FIG. 14, a negative voltage is applied to the first lens barrel 140 by the drive power supply 160. Then, a negative voltage is applied to the upper surface side electrode in the drawing of the first polymer actuator 150 via the first lens barrel 140. Further, a positive voltage is applied to the second lens barrel 141. Then, a positive voltage is applied to the lower surface side electrode in the drawing of the first polymer actuator 150 via the second lens barrel 141.

  Further, a negative voltage is applied to the third lens barrel 142 by the drive power supply 161. Then, a negative voltage is applied to the upper electrode in the drawing of the second polymer actuator 153 via the third lens barrel 142. A positive voltage is applied to the first lens barrel 140. Then, a positive voltage is applied to the lower surface side electrode in the drawing of the second polymer actuator 153 via the first lens barrel 140.

  As described above, the tongue piece 151 of the first polymer actuator 150 and the tongue piece of the second polymer actuator 153 are applied by applying a driving voltage to the first polymer actuator 150 and the second polymer actuator 152. 154 is deformed downward in FIG. Thereby, the lens frame 130 moves downward in FIG.

  Here, the same thing can be achieved by short-circuiting between the first lens barrel 140 and the third lens barrel 142 in FIG. 13 or by short-circuiting the first lens barrel 140 and the second lens barrel 141 in FIG. An effect can be obtained. However, the configuration in which the power supplies 160 and 161 are connected as shown in FIGS. 13 and 14 can move the lens frame 130 at a higher speed, and can drive the first polymer actuator 150 and the second polymer actuator 153. Advantages such as being able to maintain a neutral point can be obtained.

  As described above, the lens 120 can be moved along the optical axis AA by controlling the voltage applied to the polymer actuator 150 and the second polymer actuator 153. As a result, optical effects such as focusing and zooming can be realized.

  Further, by adopting the lens drive mechanism as shown in FIGS. 13 and 14, the length of the deformation of the polymer actuator 150 can be reduced despite the small-diameter lens drive mechanism by downsizing the imaging module. The length of the tongue piece 151 can be made relatively long. For this reason, it becomes possible to take a sufficiently large stroke of movement of the lens 120.

  In addition, power can be supplied to the polymer actuator 150 with a very simple configuration. Further, it is not necessary to bond the tongue 151 of the polymer actuator 150 and the lens frame 130. For this reason, slip occurs at both contact points. Therefore, the lens 120 can be driven more smoothly. Furthermore, there is no need to use a spring member. For this reason, the length of the lens drive mechanism 400 in the optical axis AA direction can be shortened.

  The configuration of the lens driving mechanism 500 according to the fifth embodiment of the present invention will be described with reference to FIGS. Parts that are the same as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 15 shows the top structure of the polymer actuator 150. As shown in FIG. 15, the polymer actuator 150 is composed of a plurality of deforming portions 151a, 151b, and 151c arranged on the surface of the lens barrel 140 perpendicular to the optical axis AA. The deformed portions 151a, 151b, and 151c having the same shape are formed at three positions symmetrically about the central axis, that is, the optical axis AA, along the circular opening of the lens frame 130, respectively.

  Further, the outermost peripheral portions 152 a, 152 b, and 152 c of the polymer actuator 150 are fixed on both surfaces by the first lens barrel 140 and the second lens barrel 141. In addition, the tip portions of the deforming portions 151 a, 151 b, and 151 c are fixed to the lower surface of the lens frame 130.

  16 and 17 show a cross-sectional configuration of the lens driving mechanism 500 according to the present embodiment. Each of the deforming portions 151a, 151b, and 151c includes a polymer actuator that contains an ionic fluid in an ion exchange resin and is plated with gold on the front and back surfaces. Therefore, the lens 120 can be driven along the optical axis AA based on the same principle as that described in the first embodiment. In the present embodiment, in addition to the effects of the first embodiment, the degree of freedom of arrangement of the deforming portions 151a, 151b, and 151c can be increased.

  The present invention can take various modifications without departing from the spirit of the present invention.

  As described above, the lens driving mechanism according to the present invention is suitable for a small and simple lens driving mechanism.

It is a figure which shows the perspective cross-section structure of the lens drive mechanism which concerns on Example 1 of this invention. FIG. 3 is a diagram illustrating a top surface of the polymer actuator according to the first embodiment. It is a figure which shows typically the side structure of the polymer actuator in Example 1, and the connection of a drive power supply. It is another figure which shows typically the side structure of the polymer actuator in Example 1, and the connection of a drive power supply. 3 is a diagram illustrating a cross-sectional configuration of a lens driving mechanism according to Embodiment 1. FIG. FIG. 6 is another diagram illustrating a cross-sectional configuration of the lens driving mechanism according to the first embodiment. It is a figure which shows the modification of the polymer actuator 150 and the tongue piece 151. FIG. It is a figure which shows the other modification of the polymer actuator 150 and the tongue piece 151. FIG. 6 is a diagram illustrating a cross-sectional configuration of a lens driving mechanism according to Embodiment 2. FIG. FIG. 9 is another diagram illustrating a cross-sectional configuration of the lens driving mechanism according to the second embodiment. 6 is a diagram illustrating a cross-sectional configuration of a lens driving mechanism according to Embodiment 3. FIG. FIG. 10 is another diagram illustrating a cross-sectional configuration of the lens driving mechanism according to the third embodiment. FIG. 10 is a diagram illustrating a cross-sectional configuration of a lens driving mechanism according to a fourth embodiment. FIG. 10 is another diagram showing a cross-sectional configuration of a lens driving mechanism according to Embodiment 4. FIG. 10 is a diagram showing the top surface of a polymer actuator according to Example 5. FIG. 10 is a diagram illustrating a cross-sectional configuration of a lens driving mechanism according to a fifth embodiment. FIG. 10 is another diagram showing a cross-sectional configuration of a lens driving mechanism according to Embodiment 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Lens drive mechanism 120 Lens 130 Lens frame 140 1st lens barrel 141 2nd lens barrel 142 3rd lens barrel 150 Polymer actuator 151 Tongue piece 152 Outermost periphery 153 2nd polymer actuator 160 Drive power supply 161 Drive Power supply 200 Lens drive mechanism 170 Spring member 154 Tongue piece 151a, 151b, 151c Deformation part 152a, 152b, 152c Outermost peripheral part 300, 400, 500 Lens drive mechanism

Claims (9)

A lens that moves along the optical axis and a lens frame that holds the lens;
An actuator for moving the lens frame;
A lens driving mechanism having the lens frame and a lens barrel supporting the actuator,
The actuator is a polymer actuator made of a polymer material arranged perpendicular to the optical axis,
The polymer actuator has a hollow circular shape,
Further comprising a tongue formed along the circumferential direction of the polymer actuator;
A lens driving mechanism, wherein the lens frame is moved by the tongue of the polymer actuator being deformed.   The lens driving mechanism according to claim 1, wherein a plurality of the tongue pieces of the polymer actuator are formed for one polymer actuator.   3. The lens driving mechanism according to claim 1, wherein the tongue pieces of the polymer actuator have the same shape and are formed at three or more positions in axial symmetry with respect to the optical axis. . The contact portion of the lens barrel with the polymer actuator is formed of a conductive material,
While fixing the polymer actuator using the lens barrel at a portion different from the portion where the tongue piece of the polymer actuator is formed,
The lens driving mechanism according to claim 1, wherein electric power is supplied to the polymer actuator through the lens barrel. The contact portion of the lens frame with the polymer actuator is formed of a conductive material,
A part of the lens barrel is formed of a non-conductive material,
While fixing the polymer actuator using the lens barrel at a portion different from the portion where the tongue piece of the polymer actuator is formed,
The lens driving mechanism according to claim 1, wherein electric power is supplied to the polymer actuator via the lens frame. Fixing the tip of the tongue of the polymer actuator to the lens frame;
The lens driving mechanism according to claim 1, wherein the lens frame is moved by deformation of the tongue piece of the polymer actuator. An elastic member is provided on the side opposite to the side on which the polymer actuator is disposed with respect to the lens frame,
The lens according to claim 1, wherein the lens frame is moved in two directions by a force generated by deformation of the tongue of the polymer actuator and a restoring force of the elastic member. Drive mechanism. Two polymer actuators,
Each of the polymer actuators is disposed at a position facing each other across the lens frame,
The lens frame is moved in two directions by complementarily deforming the tongue piece of one of the polymer actuators and the tongue piece of the other polymer actuator, respectively. The lens driving mechanism according to claim 5. A lens that moves along the optical axis and a lens frame that holds the lens;
An actuator for moving the lens frame;
A lens driving mechanism including a lens barrel supporting the lens frame and the actuator and having an opening;
The actuator is a polymer actuator comprising a plurality of polymer materials arranged on the surface of the lens barrel perpendicular to the optical axis,
The plurality of polymer actuators each have a deformed portion formed along the opening,
A lens driving mechanism that moves the lens frame when the deforming portion of the polymer actuator is deformed.

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