Filter Converter

Abstract

A filter converter (1), the filter converter (1) comprising: a base portion (2); a support shaft portion (3) protruding from the base portion (2); a turntable (4) supported on the support shaft portion (3) so as to be rotatable about an axis; a plurality of optical filters (51-54) arranged in a circumferential direction on the turntable (4); and a turntable drive portion (6) fixed to the base portion (2) and causing the turntable (4) to rotate about the axis; the turntable drive portion (6) comprising: a first drive source portion (61) formed by bonding a first piezoelectric element (611) and a second piezoelectric element (612) that are elongated by energization in a direction orthogonal to the elongation direction; and a first abutting portion (62) that abuts against a part of the turntable (4) and moves in a manner of depicting an elliptical locus according to the deformation of the first drive source portion (61).

Description

Technical Field

[0001] The present invention relates to a filter converter used in a camera module mounted on an electronic device (information device) such as a smartphone, and capable of arranging each of a plurality of optical filters on the optical axis of a camera lens. Background Art

[0002] As an example of prior art, the imaging device described in Japanese Patent Application Laid-Open No. 2003-259167 is cited. The filter changer included in this imaging device includes a stepping motor, a rotating disk, multiple gears, and a worm gear. The stepping motor, which drives the filter changer, has a lead screw shaft that transmits driving force to the multiple gears via the worm gear, ultimately moving the rotating disk equipped with multiple optical filters. Summary of the Invention

[0003] Problem that the invention aims to solve

[0004] This prior art requires multiple gears, screw shafts, and worm gears, making the filter converter structure complex. Furthermore, due to the low torque, the required reduction ratio increases. Consequently, this leads to high costs and a large space requirement.

[0005] In view of the above, an object of the present invention is to provide a low-cost and compact filter converter.

[0006] Solutions for solving problems

[0007] The present invention is a filter converter, which includes: a base portion; a support shaft portion, which protrudes from the base portion; a turntable, which is supported on the support shaft portion in a manner that allows rotation around an axis; a plurality of optical filters, which are arranged on the turntable in a circumferential direction; and a turntable drive portion, which is fixed to the base portion and causes the turntable to rotate around the axis; the turntable drive portion includes: a first drive source portion, which is composed of a first piezoelectric element that is extended by energization and a second piezoelectric element that is bonded in a direction orthogonal to the extension direction; and a first abutment portion, which abuts against a portion of the turntable and moves in a manner that describes an elliptical trajectory according to the deformation of the first drive source portion.

[0008] In addition, a movable filter, which is a part of the multiple optical filters, is arranged in a manner that allows it to rotate relative to the turntable, and has a circular outer peripheral shape; the turntable includes a filter driving unit that rotates the movable filter; the filter driving unit may include: a second driving source unit, which is composed of a first piezoelectric element that is extended by energization and a second piezoelectric element that is bonded in a direction orthogonal to the extension direction; and a second abutting unit, which abuts against the outer peripheral edge of the movable filter and moves in a manner that describes an elliptical trajectory according to the deformation of the second driving source unit.

[0009] In addition, the movable filter can be a polarizing filter.

[0010] In addition, rotation detection of the turntable can be performed by using a Hall element provided on one of the base portion and the turntable and a permanent magnet provided on the other.

[0011] In addition, the support shaft portion is a portion that protrudes from the base portion along the optical axis of the camera lens, and electrical wiring for supplying power to the turntable drive portion passes through the inside thereof. Even if the turntable rotates, the electrical wiring can ensure conduction.

[0012] In addition, the turntable includes a flat filter support portion and a rotation shaft portion. The rotation shaft portion extends orthogonally from the rotation center of the filter support portion toward the base portion, and the rotation shaft portion can be mounted on the support shaft portion through a bearing.

[0013] In addition, the plurality of optical filters are arranged at regular angular intervals in the circumferential direction on the turntable.

[0014] In addition, the first contact portion is a protruding portion located at the end of the turntable drive portion and protruding in the longitudinal direction of the first drive source portion, and can be provided at the boundary position between the first piezoelectric unit and the second piezoelectric unit.

[0015] In addition, the present invention is a camera module using the filter converter.

[0016] In addition, the present invention is an electronic device using the filter converter. The filter converter of the present invention can be formed into a simple structure directly driven by a piezoelectric element. Therefore, low cost and miniaturization can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. schematically shows the structure of a filter converter according to an embodiment of the present invention, and is a front view with a part shown in perspective.

[0018] Figure 2 FIG. is a longitudinal sectional view schematically showing the structure of the filter converter.

[0019] Figure 3 FIG. schematically shows the structure and operation of a drive portion included in the filter converter. DETAILED DESCRIPTION

[0020] A filter converter 1 according to an embodiment of the present invention will be described with reference to the drawings. In addition, each drawing is a schematic view, and the relationship between the illustrated contents of each drawing may be inaccurate or mismatched.

[0021] The filter converter 1 of this embodiment is used in a camera module mounted on an electronic device (information device) such as a smartphone. As Figure 1 and Figure 2 shown, the filter converter 1 of this embodiment mainly includes a base portion 2, a support shaft portion 3, a turntable 4, a plurality of optical filters 51 to 54, and a turntable drive portion 6.

[0022] The base portion 2 is a part that supports each part constituting the filter converter 1. Although not clearly shown in the figure, a space is provided in a portion of the base portion 2 that coincides with the optical axis of the camera lens. This space is a structure for allowing the light passing through each of the optical filters 51 to 54 to reach the camera lens. The optical axis of the camera lens extends in the inside-outside direction of the Figure 1 paper surface and the Figure 2 up-down direction. In this embodiment, the electrical wiring 9 passes through the inside of the base portion 2 to supply power to the filter drive portion 44.

[0023] The support shaft portion 3 is a portion that protrudes from the base portion 2 with its axis along the optical axis of the camera lens. The Figure 2 lower end portion of the support shaft portion 3 of this embodiment is embedded in the base portion 2 and fixed. In addition, in this embodiment, the electrical wiring 9 passes through the inside of the support shaft portion 3 to supply power to the turntable drive portion 6 and the filter drive portion 44. Further, since the filter drive portion 44 rotates together with the turntable 4, the electrical wiring 9 is configured to conduct while allowing rotation.

[0024] The turntable 4 is supported on the support shaft portion 3 so as to be rotatable about its axis. The turntable 4 includes a filter support portion 41 and a rotation shaft portion 42. The filter support portion 41 is in the shape of a circular plate and a flat plate, and the rotation shaft portion 42 extends orthogonally from the rotation center of the filter support portion 41 toward the base portion 2. The outer peripheral surface shape of the rotation shaft portion 42 is circular in the cross-sectional shape with respect to the axis. The rotation shaft portion 42 is mounted on the support shaft portion 3. A ball bearing 7 is provided between the rotation shaft portion 42 and the support shaft portion 3, which rotates with low friction. The filter support portion 41 rotates integrally with the rotation shaft portion 42. In addition, the filter support portion 41 is not limited to the shape of a circular plate, and can also be various shapes such as a polygonal shape. Further, the filter support portion 41 and the rotation shaft portion 42 may be integrally formed or separately formed, and become integrated through assembly.

[0025] As Figure 1As shown, a plurality of optical filters 51 to 54 are arranged on the turntable 4 in the circumferential direction. In the present embodiment, the four types of filters are interchangeable. Specifically, a polarizing filter (CPL filter) 51, a neutral density filter (ND filter) 52, a diffusion filter (a filter for forming a blurred image) 53, and a hole portion 54 (without an optical filter). In addition, in the present embodiment, the hole portion 54 is also described as a type of filter. The four types of filters 51 to 54 are arranged at regular intervals (specifically 90°) in the circumferential direction. By rotating the turntable 4, each of the filters 51 to 54 is positioned on the optical axis of the camera lens every 90° of the rotation angle. Specifically, the state where the polarizing filter (CPL filter) 51 is located on the optical axis of the camera lens is taken as a reference. As Figure 1 shown, if the turntable 4 is rotated counterclockwise by 90°, the neutral density filter (ND filter) 52 is located on the optical axis of the camera lens. If the turntable 4 is rotated counterclockwise by 90° again, the diffusion filter 53 is located on the optical axis of the camera lens. If the turntable 4 is rotated counterclockwise by 90° again, the hole portion 54 is located on the optical axis of the camera lens (in a state without an optical filter).

[0026] The rotation of the turntable 4 is detected by using a combination of a Hall element 81 provided on the base portion 2 (refer to Figure 2 , however, Figure 2 only one is shown in Figure 1 ) and a permanent magnet 82 provided on the turntable 4 (refer to Figure 1 ). Thus, the positional relationship of each of the filters 51 to 54 with respect to the camera lens can be detected. In the present embodiment, the rotation of the turntable 4 can be simply detected by using a combination of the Hall element 81 and the permanent magnet 82 of an existing unit. In addition, conversely to the present embodiment, a permanent magnet 82 can be provided on the base portion 2 and a Hall element 81 can be provided on the turntable 4. The Hall element 81 is supplied with power by a flexible circuit board (not shown). The Hall element 81 and the permanent magnet 82 are each composed of two separated by 90° with respect to the rotation center of the filter support portion 41 in the turntable 4 (refer to the Hall element 81 in Figure 1 ). As shown in Table 1, which of the two Hall elements 81 (A, B) reacts to the permanent magnet can detect which filter is located on the optical axis of the camera lens. In Table 1, the state where the Hall element 81 reacts is "ON", and the state where there is no reaction is "OFF". In addition, the content shown in Table 1 is an example and is not limited thereto.

[0027] Table 1

[0028]

[0029] The turntable drive unit 6 is fixed to the base portion 2 and rotates the turntable 4 (specifically, the rotating shaft portion 42) around the axis. In the present embodiment, asFigure 1 As shown, the two turntable driving parts 6 are arranged to be substantially V-shaped when viewed from the front. In addition, the number of the turntable driving parts 6 is not limited to two, and may also be one or more than three. The structure and outline of the operation of the turntable driving part 6 are as Figure 3 shown. The turntable driving part 6 includes a first driving source part 61 and a first abutting part 62. The three protrusions provided at the upper end edge shown in the figure of the turntable driving part 6 are electrodes 63 for energizing the piezoelectric elements 611 and 612. The piezoelectric elements are supplied with power by a flexible circuit board (not shown). At least one of the turntable driving parts 6 is provided with a support spring 64 at a radially outer position, and a force is applied in the radially inner direction by the support spring 64.

[0030] The first driving source part 61 is formed by bonding a first piezoelectric element 611 and a second piezoelectric element 612 that elongate when energized in a direction orthogonal to the elongation direction. The first piezoelectric element 611 and the second piezoelectric element 612 are also arranged in the diagonal direction, and the driving source part 61 is constituted by two first piezoelectric elements 611 and two second piezoelectric elements 612. In the present embodiment, since energizing the first piezoelectric element 611 and the second piezoelectric element 612 causes the driving source part 61 to bend and deform, only one of them is energized, and they are not energized simultaneously. However, it is also possible to set the magnitude of the voltage so as to energize both of them simultaneously.

[0031] The first abutting part 62 is a Figure 3 protrusion-shaped part located at the left end shown in the figure and protruding in the longitudinal direction of the first driving source part 61. The first abutting part 62 is provided at the boundary position between the first piezoelectric element 611 and the second piezoelectric element 612 on the left side shown in the figure. The first abutting part 62 is a part that outputs the deformation of the first driving source part 61 as a force. Therefore, the positional relationship of the first abutting part 62 with respect to the first driving source part 61 is not limited to the present embodiment, and it may also be provided on the side surface of the first driving source part 61, or offset with respect to the first piezoelectric element 611 and the second piezoelectric element 612. The first abutting part 62 abuts against the outer peripheral surface of the rotating shaft part 42 that is a part of the turntable 4, and moves in a manner of depicting Figure 3 the elliptical trajectories V1 and V2 shown by the dotted lines in

[0032] When power is supplied to the first piezoelectric element 611 in the upper left and lower right regions with shading in Figure 3 , this region extends in the horizontal direction. On the other hand, when not supplying power to Figure 3When power is supplied to the second piezoelectric element 612 located in the colorless lower left and upper right areas, the area maintains the shape of the rectangle shown in the figure. Therefore, the first piezoelectric element 611 is deformed in the direction described by the arrow in the figure, and the second piezoelectric element 612 is also deformed accordingly. Therefore, the left side portion shown in the figure of the assembly of piezoelectric elements in the driving source portion 61 (in this embodiment, an assembly of two first piezoelectric elements 611 and two second piezoelectric elements 612) is bent and deformed into an inverted U shape, and the right side portion shown in the figure is bent and deformed into a U shape, so that the whole is deformed into a "~" shape (or, an inverted and sideways S shape). Therefore, the first abutting portion 62 that abuts against the turntable 4 is bent and deformed to the left side of the figure. Figure 3 Since this movement is performed while the first piezoelectric element 611 is extending, it is achieved by Figure 3 The upper left half of the elliptical trajectory V1 shown by the dotted line on the lower left side is moved. And, due to the force involved in this movement, the turntable 4 pushed by the first contact portion 62 is moved to Figure 1 Thus, in this embodiment, the turntable driving unit 6 can directly drive the turntable 4.

[0033] Next, when power is not supplied to the first piezoelectric element 611 located in the upper left and lower right areas with shadows, the areas shrink in the horizontal direction. The aggregate of the piezoelectric elements in the first driving source portion 61 returns from the aforementioned "~" shape to the original rectangular shape shown in the figure. At this time, the first contact portion 62 moves toward Figure 3 Since this movement is performed while the first piezoelectric element 611 is shrinking, it is achieved by Figure 3 The movement of the lower right half of the elliptical trajectory V1 shown by the dotted line. As described above, by turning on and off the power supply to the first piezoelectric element 611, the first contact portion 62 depicts Figure 3 The elliptical trajectory shown in the lower left.

[0034] In contrast to the above, when power is supplied to the second piezoelectric element 612 located in the colorless lower left and upper right regions, the aggregate of the piezoelectric elements in the first driving source portion 61 is deformed into an inverted S-shape opposite to the above, so that the first contact portion 62 becomes a shape depicting Figure 3 The elliptical trajectory V2 shown in the upper left of FIG. The turntable 4 is subjected to the force involved in the movement. Figure 1 In this way, the turntable 4 can be rotated clockwise or counterclockwise depending on the energization status of each piezoelectric element 611, 612 included in the turntable drive unit 6. Furthermore, the center portion 613 of the assembly of the four piezoelectric elements 611, 612 does not move even when power is supplied to each piezoelectric element 611, 612. Therefore, when the first drive source unit 61 is fixed externally, the center portion 613, which serves as the fixed point, can be fixed.

[0035] The movable filter, which is part of the plurality of optical filters, is arranged so as to be rotatable relative to the turntable 4, and has a circular outer peripheral shape. In the present embodiment, the movable filter is a polarizing filter (CPL filter) 51. Since the polarizing filter (CPL filter) 51 can have different polarization effects according to its position in the circumferential direction relative to the optical axis of the camera lens, the image captured by the camera can be changed. Since the polarizing filter (CPL filter) 51 is rotated relative to the turntable 4, a rotation support portion 43 and a filter drive portion 44 are provided in the portion of the turntable 4 where the polarizing filter (CPL filter) 51 is disposed. A ring-shaped bracket 511 is provided at the outer edge of the polarizing filter (CPL filter) 51. The bracket 511 rotates around the filter main body portion so that the filter main body portion (the portion through which light passes) rotates relative to the turntable 4 by contacting the rotation support portion 43. In the present embodiment, the rotation support portion 43 is a plurality of spherical bodies, and supports the bracket 511 in a rotatable manner. The rotation support portion 43 of the present embodiment is composed of two spherical bodies. The filter drive portion 44 rotates the polarizing filter (CPL filter) 51.

[0036] The structure and operation principle of the filter drive portion 44 are the same as those of the turntable drive portion 6, and it includes: a second drive source portion 441, which is formed by bonding a first piezoelectric element and a second piezoelectric element (not shown, but the same as shown) that expand by energization in a direction orthogonal to the expansion direction; and a second contact portion 442, which contacts the outer peripheral edge of the bracket 511 and moves in a manner of depicting an elliptical locus according to the deformation of the second drive source portion 441. According to the energization state of the piezoelectric element provided in the filter drive portion 44, the polarizing filter (CPL filter) 51 can be rotated in the clockwise and counterclockwise directions. Thus, in the present embodiment, the filter drive portion 44 can directly drive the polarizing filter (CPL filter) 51. Figure 3 As described above, the present embodiment is a filter converter 1, and the filter converter 1 includes: a base portion 2; a support shaft portion 3 that protrudes from the base portion 2; a turntable 4 that is supported on the support shaft portion 3 so as to be rotatable around its axis; a plurality of optical filters 51 to 54 that are arranged in the circumferential direction on the turntable 4; and a turntable drive portion 6 that is fixed to the base portion 2 and rotates the turntable 4 around its axis. The turntable drive portion 6 includes: a first drive source portion 61, which is formed by bonding a first piezoelectric element 611 and a second piezoelectric element 612 that expand by energization in a direction orthogonal to the expansion direction; and a first contact portion 62, which contacts a part of the turntable 4 and moves in a manner of depicting elliptical loci V1 and V2 according to the deformation of the first drive source portion 61.

[0037] As described above,

[0038] According to this structure, the turntable driving unit 6 that generates a driving force using piezoelectric elements 611 and 612 can directly drive the turntable 4.

[0039] In addition, a movable filter 51, which is part of the plurality of optical filters 51 to 54, is provided so as to be rotatable relative to the turntable 4, and has a circular outer peripheral shape. The turntable 4 is provided with a filter driving unit 44 for rotating the movable filter 51. The filter driving unit 44 can include: a second driving source unit 441 formed by bonding a first piezoelectric element and a second piezoelectric element that elongate when energized in a direction orthogonal to the elongation direction; and a second abutting portion 442 that abuts against the outer peripheral edge of the movable filter 51 and moves in an elliptical locus according to the deformation of the second driving source unit 441.

[0040] According to this structure, the filter driving unit 44 that generates a driving force using piezoelectric elements can directly drive the movable filter 51.

[0041] In addition, the movable filter 51 can be a polarizing filter (CPL filter) 51.

[0042] According to this structure, the polarizing filter (CPL filter) 51 can be easily rotated using the filter driving unit, and the polarizing effect of the polarizing filter varies according to its position in the circumferential direction relative to the optical axis of the camera lens.

[0043] In addition, the rotation of the turntable 4 can be detected using a Hall element 81 provided on one of the base portion 2 and the turntable 4 and a permanent magnet 82 provided on the other.

[0044] According to this structure, the rotation of the turntable 4 can be simply detected by an existing method.

[0045] In addition, the support shaft portion 3 is a part that protrudes from the base portion along the optical axis of the camera lens, and the electrical wiring 9 that supplies power to the turntable driving unit 6 passes through its interior. Even when the turntable 4 rotates, the electrical wiring 9 can ensure electrical continuity.

[0046] In addition, the turntable 4 includes a flat filter support portion 41 and a rotating shaft portion 42. The rotating shaft portion 42 extends orthogonally from the center of rotation of the filter support portion 41 toward the base portion 2, and the rotating shaft portion 42 can be mounted on the support shaft portion 3 through a bearing 7.

[0047] In addition, the plurality of optical filters 51 to 54 can be arranged at regular angular intervals in the circumferential direction on the turntable 4.

[0048] In addition, the first abutting portion 62 is a protruding portion located at the end of the turntable driving portion 6 and protruding in the longitudinal direction of the first driving source portion 61, and can be provided at the boundary position between the first piezoelectric unit 611 and the second piezoelectric unit 612.

[0049] In addition, the present invention is a camera module using the filter converter 1.

[0050] In addition, the present invention is an electronic device using the filter converter 1.

[0051] As described above, the filter converter 1 of the present embodiment can be formed into a simple structure directly driven by the piezoelectric elements 611 and 612. Therefore, low cost and miniaturization can be achieved. In addition, by using high-output piezoelectric elements, intermediate transmission units and reduction units such as gears are not required, and high-speed rotation can be performed by direct drive. Therefore, the desired optical filters 51 to 54 can be quickly positioned on the optical axis of the camera lens, and thus a high-performance filter converter 1 can be provided.

[0052] Description of Reference Numerals

[0053] 1: Filter Converter

[0054] 2: Base Portion

[0055] 3: Support Shaft Portion

[0056] 4: Turntable

[0057] 41: Filter Support Portion

[0058] 42: Rotation Shaft Portion

[0059] 44: Filter Driving Portion

[0060] 441: Second Driving Source Portion (Filter Driving Portion)

[0061] 442: Second Abutting Portion (Filter Driving Portion)

[0062] 51: Optical Filter, Movable Filter, Polarizing Filter (CPL Filter)

[0063] 52: Optical Filter, Neutral Density Filter (ND Filter)

[0064] 53: Optical Filter, Diffusion Filter

[0065] 54: Optical Filter, Hole Portion

[0066] 6: Turntable Driving Portion

[0067] 61: First Driving Source Portion (Turntable Driving Portion)

[0068] 611: First piezoelectric element

[0069] 612: Second piezoelectric element

[0070] 62: First abutting portion (turntable driving portion)

[0071] 7: Bearing

[0072] 81: Hall element

[0073] 82: Permanent magnet

[0074] 9: Electrical wiring

[0075] V1, V2: Elliptical trajectory

Claims

1. A filter converter, characterized in that, have: base portion; a support shaft portion protruding from the base portion; a turntable supported on the support shaft portion in a manner rotatable around an axis; a plurality of optical filters arranged on the rotating disk along a circumferential direction; and a turntable driving portion, which is fixed to the base portion and causes the turntable to rotate around an axis; The turntable drive unit includes: a first drive source unit, which is composed of a first piezoelectric element that expands when energized and a second piezoelectric element bonded together in a direction perpendicular to the expansion direction; and a first abutment unit that abuts against a portion of the turntable and moves in a manner describing an elliptical trajectory according to the deformation of the first drive source unit. The support shaft portion is a portion whose axis protrudes from the base portion along the optical axis of the camera lens, and through which an electrical wiring for supplying power to the turntable drive portion passes. Even when the turntable rotates, the electrical wiring maintains electrical continuity.

2. The filter converter according to claim 1, wherein: A movable filter as part of the plurality of optical filters is provided in a manner rotatable relative to the turntable and has a circular outer peripheral shape; The turntable includes a filter driving unit for rotating the movable filter; The filter driving unit includes: a second driving source unit, which is composed of a first piezoelectric element that stretches when energized and a second piezoelectric element bonded together in a direction perpendicular to the stretching direction; and a second abutting unit that abuts against the outer peripheral edge of the movable filter and moves in a manner describing an elliptical trajectory according to the deformation of the second driving source unit.

3. The filter converter according to claim 2, wherein: The movable filter is a polarizing filter.

4. The filter converter according to any one of claims 1 to 3, characterized in that The rotation of the turntable is detected by using a permanent magnet provided on one of the base and the turntable and a Hall element provided on the other.

5. The filter converter according to any one of claims 1 to 3, characterized in that: The turntable includes a flat plate-shaped filter support portion and a rotation shaft portion, wherein the rotation shaft portion extends orthogonally from the rotation center of the filter support portion toward the base portion. The rotating shaft portion is mounted on the supporting shaft portion via a bearing.

6. The optical filter converter according to any one of claims 1 to 3, characterized in that: The plurality of optical filters are arranged on the turntable at intervals of a certain angle along the circumferential direction.

7. The optical filter converter according to claim 2, wherein: The first contact portion is a protruding portion located at an end of the turntable drive portion and protruding in the longitudinal direction of the first drive source portion, and is provided at a boundary between the first piezoelectric element and the second piezoelectric element.

8. A camera module, characterized in that: Use the filter converter according to any one of claims 1 to 7.

9. An electronic device, characterized in that: Use the filter converter according to any one of claims 1 to 7.

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