Blade driving device and optical apparatus

A blade driving device includes: a board including an opening; first and second blades opening and closing the opening; first and second actuators arranged adjacent to each other and respectively driving the first and second blades, and respectively including first and second stators, first and second rotors, and first and second coils; a printed circuit board; and solder portions electrically connecting the first and second coils with the printed circuit board; wherein the solder portions includes: first and second solder portions respectively connecting one end and another end of the first coil with the printed circuit board; and third and fourth solder portions respectively connecting one end and another end of the second coil with the printed circuit board; and the first, second, third, and fourth solder portions face one another.

BACKGROUND

(i) Technical Field

The present invention relates to blade driving devices and optical apparatuses.

(ii) Related Art

Japanese Unexamined Patent Application Publication No. 2009-175365 discloses a blade driving device driving different blades by respective two actuators.

The two actuators each have a coil. These two coils are soldered to a printed circuit board. In a case where points in which the two coils are soldered to the printed circuit board are arranged over a wide range, the soldering workability might deteriorate.

Further, in soldering work, flux might be scattered from the melted solder. Thus, in the case where points in which the two coils are soldered to the printed circuit board are arranged over a wide range, the flux might be scattered over a wide range.

SUMMARY

It is thus object of the present invention to provide a blade driving device suppressing broad scattering of flux and improving soldering workability, and an optical apparatus having the same.

According to an aspect of the present invention, there is provided a blade driving device including: a board including an opening; first and second blades opening and closing the opening; first and second actuators arranged adjacent to each other and respectively driving the first and second blades, and respectively including first and second stators, first and second rotors, and first and second coils; a printed circuit board; and solder portions electrically connecting the first and second coils with the printed circuit board; wherein the solder portions includes: first and second solder portions respectively connecting one end and another end of the first coil with the printed circuit board; and third and fourth solder portions respectively connecting one end and another end of the second coil with the printed circuit board; and the first, second, third, and fourth solder portions face one another.

DETAILED DESCRIPTION

FIGS. 1 and 2are exploded perspective views of a blade driving device1according to the present embodiment. The blade driving device1is also referred to as a focal plane shutter. The blade driving device1is employed in an optical apparatus such as a digital camera or a still camera. The blade driving device1includes boards10,10A, and10B, a leading blade20A, a trailing blade20B, arms31a,32a,31b, and32b, and actuators70aand70b. The boards10,10A, and10B respectively include openings11,11A, and11B. The leading blade20A and the trailing blade20B open and close these openings11,11A, and11B. The actuators70aand70bdrive the leading blade20A and the trailing blade20B, respectively.

The leading blade20A and the trailing blade20B each includes plural blades. Each of the leading blade20A and the trailing blade20B can shift between an overlapped state where the plural blades overlap one another and an expanded state where the plural blades are expanded. These plural blades in the overlapped state recede from the opening11to cause the opening11to be in a fully opened state. These plural blades in the expanded state close the opening11to cause the opening11to be in a fully closed state.FIGS. 1 and 2illustrate the blade driving device1in the fully opened state.

The leading blade20A is connected with the arms31aand32a. The trailing blade20B is connected with the arms31band32b. As illustrated inFIG. 2, the arms31a,32a,31b, and32bare rotatably supported by spindles14a,15a,14b, and15bprovided in the board10, respectively.

Drive members40aand40bdrive the arms31aand31b, respectively. Thus, the arms31aand31bcorrespond to driven members that are driven by the drive members40aand40band that drive the leading blade20A and the trailing blade20B, respectively. The drive members40aand40bare provided with drive pins43aand43bconnected with the arms31aand31b, respectively. The boards10,10A, and10B are respectively formed with escape slots13a,13aA, and13aB for permitting the movement of the drive pin43a. Likewise, they are respectively formed with escape slots13b,13bA, and13bB for permitting the movement of the drive pin43b. The drive members40aand40bwill be described later in detail.

The board10is assembled with holders80and90holding the actuators70aand70b. The holder80is formed with support walls81aand81bthat respectively support the actuators70aand70b. The holder80is secured on the board10. The holders80and90are secured to each other. The holders80and90are made of a synthetic resin.

The actuator70aincludes: a rotor72arotatably supported by the holder80; a stator74aexcited to generate magnetic force between the stator and the rotor72a; and a coil76afor exciting the stator74a. The rotor72ais fitted with an output member50a. The output member50ais connected with the drive member40a. Therefore, the rotation of the rotor72adrives the output member50aand the drive member40ato drive the arm31aand the leading blade20A. The actuator70bhas the same arrangement. The rotation of a rotor72bof the actuator70brotates the drive member40bto drive the trailing blade20B.

The support walls81aand81bof the holder80are respectively formed with escape holes85aand85b. The escape hole85areceives a connection portion where the drive member40aand the output member50aare connected with each other. Likewise, the escape hole85breceives a connection portion where the drive member40band an output member50bare connected with each other. The holder80is formed with spindle portions87aand87bfor supporting the rotors72aand72bfor rotation, respectively. A printed circuit board100is secured to outer portions of the holders80and90. The printed circuit board100supplies the coils76aand76bwith power. The printed circuit board100is a flexible printed circuit board with flexibility.

FIG. 3is a partially enlarged view ofFIG. 1. The drive members40aand40bare respectively rotatably supported by spindle portions84aand84bprovided on the holder80. The drive members40aand40bare respectively provided with gear portions45aand45b. The output members50aand50bare respectively provided with gear portions55aand55b. The gear portions45aand55amesh with each other, and the gear portions45band55bmesh with each other. Thus, the rotation of the rotor72acauses the output member50ato drive, thereby driving the drive member40a. The same is true for the rotor72b, the output member50b, and the drive member40b.

The coil76aand76bare respectively wound around coil bobbins78aand78b. The coil bobbin78aand78bare respectively attached to the stators74aand74b. The coil bobbin78ais provided with terminal portions78a1and78a2around which one end and the other end of the coil76aare respectively wound. Similarly, the coil bobbin78bis provided with terminal portions78b1and78b2around which one end and the other end of the coil76bare respectively wound. The terminal portions78a1,78a2,78b1, and78b2face one another and extend to the holder80side that is, the board10side. The holder80is formed with a receiving hole89afor receiving the terminal portions78a1and78a2, and with a receiving hole89bfor receiving terminal portions78b1and78b2.

The printed circuit board100includes: a portion103provided at its one end with a connector portion101and attached to the holder90side; a portion105attached to the side surface of the holder80; and an inserted portion107inserted between the holder80and the board10. On the inserted portion107, the pattern to which the coils76aand76bare connected is provided. The portions103and105are an example of exposed portions exposed to the outside of the holder80and90. They will be described later in detail.

FIG. 4is a rear view of the blade driving device1after completion.FIG. 5is a side view of the blade driving device1after completion. The terminal portions78a1,78a2,78b1, and78b2are connected with the inserted portion107by soldering. Specifically, solder portions Sa1, Sa2, Sb1, and Sb2respectively connect the terminal portions78a1,78a2,78b1, and78b2with the inserted portion107. That is, the solder portions Sa1and Sa2electrically connect one end and the other end of the coil76awith the printed circuit board100. The Solder portions Sb1and Sb2electrically connect one end and the other end of the coil76bwith the printed circuit board100. The solder portions Sa1, Sa2, Sb1, and Sb2are an example of solder portions. The solder portions Sa1, Sa2, Sb1, and Sb2protrude to the board10side.

As illustrated inFIG. 5, a recess portion80R is formed on the surface of the holder80facing the board10. The terminal portions78a1and78a2protrude into the recess portion80R through the receiving hole89aas illustrated inFIG. 3. Likewise, the terminal portions78b1and78b2protrude into the recess portion80R through the receiving hole89b. The solder portions Sa1, Sa2, Sb1, and Sb2are located in the recess portion80R.

As illustrated inFIGS. 4 and 5, these solder portions Sa1, Sa2, Sb1, and Sb2closely face one another, and are arranged together at a place. Specifically, when viewed in the optical axis direction as illustrated inFIG. 4, the solder portions Sa1, Sa2, Sb1, and Sb2are positioned to be sandwiched between the coil bobbins78aand78b, and also between the drive members40aand40b.

FIGS. 6A and 6Bare explanatory views of a blade driving device1xof a comparative example. Incidentally, similar components are designated with similar reference numerals and a description of those components will be omitted. Terminal portions78a1xand78a2xof a coil bobbin78axof an actuator70axare formed at a position to sandwich the coil bobbin78ax, when viewed in the optical axis direction. The same is true for terminal portions78b1xand78b2xof a coil bobbin78bxof an actuator70bx. The terminal portion78a1xof the coil bobbin78axand the terminal portion78b1xof the coil bobbin78bxare formed at a position to sandwich the two coil bobbins78axand78bx. Solder portions Sa1x, Sa2x, Sb1x, and Sb2x, electrically respectively connecting such terminal portions78a1x,78a2x,78b1x, and78b2xto a printed circuit board100x, are arranged over a wide range. Therefore, soldering workability might be deteriorated. Also, flux might be scattered over a wide range.

The scattering of the flux might degrade sliding property of a movable member located around the solder portion, which might cause a drive malfunction. In particular, the broad scattering of the flux might increase the possibility of the malfunction. Also, the removing of the flux requires cleaning over a wide range. In this way, the workability might deteriorate, so the production efficiency might decrease.

In the blade driving device1according to the present embodiment, the solder portions Sa1, Sa2, Sb1, and Sb2are not formed at a position to sandwich the coil bobbin78aand78b, and are not formed at a position to sandwich the opening11. The solder portions Sa1, Sa2, Sb1, and Sb2closely face one another, and are arranged together in one place. Therefore, the soldering workability improves, so this suppresses the scattering of the flux over a wide range.

Further, as illustrated inFIG. 6B, as for the blade driving device1x, the terminal portions78a1x,78a2x,78b1x, and78b2xextend to the upper surface side of the holder90and protrude outwardly, and the solder portions Sa1x, Sa2x, Sa1x, and Sb2xare also provided in the outer side of the holder90. For this reason, careful handling of the blade driving device1xis required. Also, when the blade driving device1xis mounted on a camera, care must be taken so that the solder portion Sa1xand the like do not touch other components within the camera. In addition, the size of the blade driving device1xis increased in the optical axis direction.

In the present embodiment, as illustrated inFIG. 5, the terminal portions78a1,78a2,78b1, and78b2extend to the board10side, and the solder portions Sa1, Sa2, Sb1, and Sb2face the board10, in other words, protrude to the board10side and are located within the recess portion80R. Although the solder portions Sa1, Sa2, Sb1, and Sb2protrude to the board10in this way, they are not exposed to the outside. It is therefore easy to handle the blade driving device1according to the present embodiment, and to mount it on the camera. Also, the blade driving device1is thinned in the optical axis direction.

Incidentally, before the holders80and90are assembled to the board10, the actuators70aand70band the printed circuit board100are assembled to the holders80and90. After that, and the holders80and90are assembled to the board10. Thus, it is possible to handle the holders80and90assembled with the actuators70aand70band the printed circuit board100as a actuator unit, before the holders80and90are assembled to the board10. At this time, as illustrated inFIG. 5, the terminal portions78a1,78a2,78b1, and78b2, and the solder portions Sa1, Sa2, Sb1, and Sb2are located within the recess portion80R, and do not protrude from a bottom surface of the holder80. It is also easy to handle the actuator unit.

As illustrated inFIGS. 4 and 5, the drive member40aand the output member50aare at least partially located between the board10, and the stator74aand the coil76a. Similarly, the drive member40band the output member50bare at least partially located between the board10, and the stator74band the coil76b. Therefore, as illustrated inFIG. 5, the space for arranging the drive members40aand40band the output members50aand50bis ensured between the board10and the actuators70aand70bin the optical axis direction. The recess portion80R is formed within this space, and the solder portions Sa1, Sa2, Sb1, and Sb2protruding to the board10side is also located within this space. Thus, the dead space is effectively used, thereby suppressing the increase in the thickness in the optical axis direction.

Also, as illustrated inFIG. 3, the gear portion45aof the drive member40aand the gear portion55aof the output member50aare positioned in the escape hole85aof the holder80. This reduces the thickness of the blade driving device1.

Also, the size of the escape hole85ais set so as to permit the connection between the gear portions45aand55a. Thus, the escape hole85ais comparatively large. This reduces the weight of the holder80.

Also, the gear portions45aand55aare connected with each other in the escape hole85a, thereby arranging the drive member40aand the output member50aclose to each other. This reduces the whole size of the drive member40aand the output member50a. Further, this reduces the total weight of the drive member40aand the output member50a. Thus, the blade driving device1is reduced in weight.

As illustrated inFIG. 4, the drive pin43aoverlaps the rotor72a. Specifically, a part of a trajectory of the drive pin43aoverlaps the rotor72a. The rotor72aand the drive member40aare arranged in such a manner, thereby reducing the size of the blade driving device1in the planar direction.

The rotors72aand72bare arranged to sandwich the coils76aand76b. In other words, the rotors72aand72bare respectively located at both ends of the holder80in the movable direction of the leading blade20A and the trailing blade20B. In such a way, although the actuators70aand70bare adjacent to each other, the rotors72aand72bare spaced apart from each other. This prevents the rotors72aand72bfrom magnetically influencing each other and from influencing the driving properties of the rotors72aand72b. It is therefore possible to ensure the desired driving properties of the leading blade20A and the trailing blade20B.

Herein, the leading blade20A and the trailing blade20B are an example of first and second blades. The actuators70aand70bare an example of first and second actuators. The rotors72aand72bare an example of first and second rotors. The coils76aand76bare an example of first and second coils. The stators74aand74bare an example of first and second stators. The solder portions Sa1, Sa2, Sb1, and Sb2are an example of first, second, third, and fourth solder portions, respectively.

Additionally, the actuators70aand70bare arranged such the longitudinal directions thereof are the same as the movable direction of the leading blade20A and the trailing blade20B. Further, the actuators70aand70bare arranged in the longitudinal direction. Furthermore, the rotors72aand72bare respectively arranged at both ends of the whole region of the actuators70aand70bin its longitudinal direction. It is therefore possible to ensure the further interval between the rotors72aand72b. This prevents the rotors72aand72bfrom magnetically influencing each other and from influencing the driving properties of the rotors72aand72b.

The drive member40ais arranged to overlap the stator74aand the coil76ain the optical axis direction. Likewise, the drive member40bis arranged to overlap the stator74band the coil76bin the optical axis direction. Therefore, the size of the blade driving device is reduced in the planar direction perpendicular to the optical axis.

The axis of the rotation of the drive member40aoverlaps the stator74aand the coil76a, and is positionally displaced from the axis of the rotor72a. Similarly, the axis of rotation of the drive member40boverlaps the stator74band the coil76b, and is positionally displaced from the axis of the rotor72b.

While the exemplary embodiments of the present invention have been illustrated in detail, the present invention is not limited to the above-mentioned embodiments, and other embodiments, variations and modifications may be made without departing from the scope of the present invention.

In the above embodiment, the solder portions Sa1, Sa2, Sb1, and Sb2that face the board10and that are located within the recess portion80R are described as an example, but they are not limited. The solder portions Sa1, Sa2, Sb1, and Sb2may extend to the upper surface side of the holder90, protrude to the outside thereof, and be provided outside the holder90. Also, they may protrude to a side surface side of the holder80and be provided outside the holder80. The solder portions Sa1, Sa2, Sb1, and Sb2face one another and are arranged together in one place, thereby improving the soldering workability and suppressing the broad scattering of the flux.

In the above embodiment, the blade driving device1is described as an example of the focal plane shutter in which the actuators70aand70brespectively drive the leading blade20A and the trailing blade20B, but they are not limited. As for a focal plane shutter in which biasing force of springs drives the leading blade and the trailing blade, solder portions, electrically connecting the printed circuit board with electromagnets for keeping the biasing force for the leading blade and the trailing blade, may face one another and be arranged together in one place.