Optical unit with shake correcting function
An optical unit may include a fixed body; a movable module which holds an optical element; a swing support point which swingably supports the movable module; a shake correction drive mechanism which swings the movable module with the swing support point as a swing center around two axial lines intersecting an optical axis direction of the optical element between an outer peripheral face of the movable module and the fixed body; a first photo reflector provided between a bottom part of the movable module and the fixed body at a position superposing on one of the two axial lines and that detects displacement of the movable module; and a second photo reflector provided between the bottom part of the movable module and the fixed body at a position superposing on the other of the two axial lines and that detects displacement of the movable module.
1. An optical unit with a shake correcting function comprising:
a fixed body;
a movable module which holds an optical element;
a swing support point which swingably supports the movable module between a bottom part of the movable module and the fixed body;
a shake correction drive mechanism which is structured to swing the movable module with the swing support point as a swing center around two axial lines intersecting an optical axis direction of the optical element between an outer peripheral face of the movable module and the fixed body;
a first photo reflector which is provided between a bottom part of the movable module and the fixed body at a position superposing on one of the two axial lines in the optical axis direction and is structured to detect displacement of the movable module; and
a second photo reflector which is provided between the bottom part of the movable module and the fixed body at a position superposing on the other of the two axial lines in the optical axis direction and is structured to detect displacement of the movable module;
wherein the bottom part of the movable module includes a circuit board on which the first photo reflector and the second photo reflector are mounted, and
a face of the circuit board on an opposite side to a face where the first photo reflector and the second photo reflector are mounted is mounted with an imaging element.
2. The optical unit with a shake correcting function according to claim 1 , further comprising a flexible circuit board which is extended in a direction intersecting the optical axis direction between the bottom part of the movable module and the fixed body so as to avoid positions superposing on the first photo reflector and the second photo reflector in the optical axis direction,
wherein each of the first photo reflector and the second photo reflector is provided with a rectangular planar shape, and extended directions of long sides of the first photo reflector and the second photo reflector are parallel to an extended direction of the flexible circuit board.
3. The optical unit with a shake correcting function according to claim 2 , wherein the light emitting part of the first photo reflector is disposed on a side where the second photo reflector is located and the light emitting part of the second photo reflector is disposed on a side where the first photo reflector is located, or the light receiving part of the first photo reflector is disposed on a side where the second photo reflector is located and the light receiving part of the second photo reflector is disposed on a side where the first photo reflector is located.
4. The optical unit with a shake correcting function according to claim 2 , further comprising
a light shielding layer which is provided on at least two side faces of four side face parts of the first photo reflector in which the four side face parts are set in directions intersecting the optical axis direction, at least the two side faces provided with the light shielding layer being disposed on a side where the second photo reflector is located, and
a light shielding layer which is provided on at least two side faces of four side face parts of the second photo reflector in which the four side face parts are set in directions intersecting the optical axis direction, at least the two side faces provided with the light shielding layer being disposed on a side where the first photo reflector is located.
5. The optical unit with a shake correcting function according to claim 2 , further comprising:
a first reflection part which is provided in the fixed body so as to superpose on the first photo reflector in the optical axis direction, and
a second reflection part which is provided in the fixed body so as to superpose on the second photo reflector in the optical axis direction,
wherein the first photo reflector and the second photo reflector are provided in the bottom part of the movable module, and
wherein the first reflection part and the second reflection part are recessed in a direction apart from the bottom part of the movable module with respect to a portion of the fixed body which is located around the first reflection part and a portion of the fixed body which is located around the second reflection part.
6. The optical unit with a shake correcting function according to claim 2 , further comprising:
a first reflection part which is provided in the fixed body so as to superpose on the first photo reflector in the optical axis direction, and
a second reflection part which is provided in the fixed body so as to superpose on the second photo reflector in the optical axis direction,
wherein the first photo reflector and the second photo reflector are provided in the bottom part of the movable module, and
wherein the first reflection part and the second reflection part are formed in a same plane with respect to a portion of the fixed body which is located around the first reflection part and a portion of the fixed body which is located around the second reflection part.
7. The optical unit with a shake correcting function according to claim 2 , wherein a portion of the fixed body which faces the bottom part of the movable module is structured of a metal member that is non-magnetized by heat treatment.
8. The optical unit with a shake correcting function according to claim 1 , further comprising
a light shielding layer which is provided on at least two side faces of four side face parts of the first photo reflector in which the four side face parts are set in directions intersecting the optical axis direction, at least the two side faces provided with the light shielding layer being disposed on a side where the second photo reflector is located, and
a light shielding layer which is provided on at least two side faces of four side face parts of the second photo reflector in which the four side face parts are set in directions intersecting the optical axis direction, at least the two side faces provided with the light shielding layer being disposed on a side where the first photo reflector is located.
9. The optical unit with a shake correcting function according to claim 8 , further comprising:
a first reflection part which is provided in the fixed body so as to superpose on the first photo reflector in the optical axis direction, and
a second reflection part which is provided in the fixed body so as to superpose on the second photo reflector in the optical axis direction,
wherein the first photo reflector and the second photo reflector are provided in the bottom part of the movable module, and
wherein the first reflection part and the second reflection part are recessed in a direction apart from the bottom part of the movable module with respect to a portion of the fixed body which is located around the first reflection part and a portion of the fixed body which is located around the second reflection part.
10. The optical unit with a shake correcting function according to claim 8 , further comprising:
a first reflection part which is provided in the fixed body so as to superpose on the first photo reflector in the optical axis direction, and
a second reflection part which is provided in the fixed body so as to superpose on the second photo reflector in the optical axis direction,
wherein the first photo reflector and the second photo reflector are provided in the bottom part of the movable module, and
wherein the first reflection part and the second reflection part are formed in a same plane with respect to a portion of the fixed body which is located around the first reflection part and a portion of the fixed body which is located around the second reflection part.
11. The optical unit with a shake correcting function according to claim 8 , wherein a portion of the fixed body which faces the bottom part of the movable module is structured of a metal member that is non-magnetized by heat treatment.
12. The optical unit with a shake correcting function according to claim 1 wherein a portion of the fixed body which faces the bottom part of the movable module is structured of a metal member that is non-magnetized by heat treatment.
13. The optical unit with a shake correcting function according to claim 1 , further comprising a flexible circuit board which is disposed between the bottom part of the movable module and the fixed body and is provided with a strip-shaped portion having a folded-back portion that is extended in a direction intersecting the optical axis direction and is folded back in a reverse direction and fixed to the movable module,
wherein the strip-shaped portion is disposed so as to avoid positions superposing on the first photo reflector and the second photo reflector in the optical axis direction.
14. The optical unit with a shake correcting function according to claim 13 , wherein
the strip-shaped portion of the flexible circuit board is formed with a slit which is extended along an extended direction of the strip-shaped portion in a midway portion in the extended direction, and
one of the first photo reflector and the second photo reflector is disposed at a position superposing on the slit of the flexible circuit board.
15. The optical unit with a shake correcting function according to claim 14 , wherein
the shake correction drive mechanism comprises four flat plate-shaped permanent magnets, which are fixed to four outer faces of a case having a rectangular tube-shaped body part structuring the movable module, and four coil parts which are disposed on four inner faces of a cover having a rectangular tube-shaped body part structuring the fixed body,
the movable module is swung around the two axial lines by the four permanent magnets and the four coil parts, and
the extended direction of the slit which is formed in the strip-shaped portion of the flexible circuit board is the same direction as one of the two axial lines.
16. The optical unit with a shake correcting function according to claim 14 , wherein
each of the first photo reflector and the second photo reflector is structured of a light emitting part, a light receiving part and a light intercepting part between the light emitting part and the light receiving part, and
the light emitting part and the light receiving part of each of the first photo reflector and the second photo reflector are disposed in the extended direction of the slit which is formed in the strip-shaped portion of the flexible circuit board.
17. The optical unit with a shake correcting function according to claim 16 , further comprising;
a light shielding layer provided on at least a side face of the first photo reflector which is located on a second photo reflector side, or
a light shielding layer provided on at least a side face of the second photo reflector which is located on a first photo reflector side.