JP4464205B2 - Mirror drive device and photographing device - Google Patents

Description

  The present invention relates to a mirror driving device and a photographing device that drive a mirror that can move forward and backward with respect to a photographing optical path.

  By a motor, a mirror drive cam gear having a cam portion, a mirror drive lever for rotating the movable mirror by a cam portion lift of the mirror drive cam gear, a shutter drive cam gear having a cam portion, and a lift of the cam portion of the shutter drive cam gear There has been proposed a camera in which a drive mechanism having a shutter drive lever for charging the shutter is incorporated (see, for example, Patent Document 1). In this drive mechanism, the mirror drive cam gear and the shutter drive cam gear are directly engaged, and a transmission gear that transmits a rotational force around one direction of the motor is engaged with one of the cam gears. Yes.

  However, since the mirror drive cam gear, the shutter drive cam gear, and the transmission gear that engages with one of these cam gears are arranged so as to engage in series, when focusing on the other cam gear, In comparison, since the number of gear stages to which the motor driving force is transmitted is increased by one step, the driving efficiency is not good.

  Further, since the mirror drive cam gear and the shutter drive cam gear are directly engaged, these cam gears rotate in opposite directions. For this reason, the arrangement of the rotation shafts of the mirror drive lever and the shutter drive lever cannot be an ideal arrangement considering the drive efficiency.

  Furthermore, since the mirror drive cam gear and the shutter drive cam gear are directly engaged, and the cam gear occupies a space in a vertical shape when viewed in the rotational axis direction, the arrangement of the mirror drive lever and the shutter drive lever is respectively Therefore, it is not possible to make an ideal arrangement in consideration of the drive efficiency, which is disadvantageous in terms of drive efficiency, and may increase the size of the camera.

  On the other hand, a drive mechanism having a transmission gear shaft that is coaxially arranged with a mirror transmission gear that engages with a mirror drive cam gear and a shutter transmission gear that engages with a shutter drive cam gear and that is driven by a motor is disclosed. (For example, refer to Patent Document 2). According to the above configuration, since the driving force of the motor is directly transmitted from the transmission gear corresponding to each of the mirror driving cam gear and the shutter driving cam gear, the transmission gear is engaged with one cam gear, and the other cam gear is engaged with the other cam gear. Compared with the configuration in which the cam gear is engaged, the difference in drive efficiency due to the number of gear stages can be reduced. Further, by rotating the mirror drive cam gear and the shutter drive cam gear in the same direction, the arrangement of the rotation shafts of the mirror drive lever and the shutter drive lever can be made an ideal arrangement in consideration of drive efficiency.

  However, the above mechanism causes an increase in the number of parts, and there is a possibility that the phases of the mirror drive cam gear and the shutter drive cam gear shift in the assembly operation. Furthermore, since the mirror drive cam gear and the shutter drive cam gear are connected by the transmission gear, a phase shift occurs due to the backlash of the gear, and the rotation of either one of the cam gears is feedback controlled, so that the mirror drive In addition, the interlocking drive of the shutter drive cannot be performed with high accuracy.

  In the two driving mechanisms described above, when the mirror is retracted from the imaging optical path to the outside of the imaging optical path, or when entering the imaging optical path from the outside of the imaging optical path, the mirror is driven by a cam lift. Mirror drive time is delayed due to changes.

  Patent Document 3 discloses a mirror driving mechanism that drives a mirror at high speed. The mirror driving mechanism includes a first engaging portion that positions the mirror in the photographing optical path, a first spring that biases the mirror in a direction to retract the mirror out of the photographing optical path, and a first spring that positions the mirror out of the photographing optical path. Two engaging portions, a second spring that biases the mirror in the direction of entering the imaging optical path, an electromagnetic magnet that releases the engagement in the first and second engaging portions, and the first and second And a motor for charging the spring.

  However, although this mirror drive mechanism can drive the mirror at a high speed, it requires a plurality of drive sources and has a large number of components to be a very expensive mechanism. Further, there is a limit to the releasing force of the electromagnetic magnet that releases the engagement by the engaging portion, and the positioning force by the engaging portion cannot be increased.

There is also disclosed an imaging apparatus that has a mirror drive mechanism that allows a mirror to advance and retreat with respect to an imaging optical path by a biasing force of a charged drive spring, and that uses a single motor as a drive source (see Patent Document 4). .
Japanese Patent Publication No. 7-27156 (Fig. 3) Japanese Patent Laid-Open No. 2002-23221 (FIG. 2) Japanese Unexamined Patent Publication No. 1-134443 (FIGS. 2 to 5) JP 2002-174850 A (FIGS. 1 and 2)

  However, in the above mechanism, when the mirror is driven from outside the photographing optical path into the photographing optical path, it is necessary to disengage the ascending lever. However, when the motor is driven to release the engagement, the mirror is moved out of the photographing optical path. Since the charge driving of the spring biased toward the head is also performed at the same time, the load applied to the motor increases, and it takes time to release the engagement.

  Also, the rotation direction of the motor differs between when the mirror is retracted out of the shooting optical path and when the mirror is moved into the shooting optical path, and the cam gear is forcibly locked by mechanically locking to stop the rotation of the motor. Since it is stopped, the mechanical burden increases.

  In order to solve the above problems, the first configuration of the mirror driving device of the present invention is a mirror movable to a first position arranged in the photographing optical path and a second position retracted outside the photographing optical path. A first biasing member that generates a biasing force that drives the mirror from the second position to the first position, and an attachment that drives the mirror from the first position to the second position. A second urging member that generates urging force; a holding member that can hold the first urging member in a charged state; a charge unit that charges the second urging member; and the second urging member. A first cam having a release portion for releasing the charge of the biasing member; a second cam for releasing the holding by the holding member; and a motor for driving both the first and second cams. The motor drives the first and second cams in only one direction. Characterized in that it.

  According to the first configuration of the mirror driving device of the present invention, the mirror can be moved to the first and second positions by driving the first and second cams in only one direction by the motor. . Therefore, the driving force of the motor rotating in the other direction can be assigned to driving of other driving mechanisms (for example, strobe driving, film cartridge or recording medium insertion driving, film feeding driving, etc.). As a result, it is not necessary to use a separate motor to drive the other drive mechanism, so that an inexpensive mirror drive device with fewer components and easy assembly can be provided.

Here, in the first configuration of the mirror driving device, the shutter has a shutter, and when the second biasing member is charged to the first cam by the charging unit, the shutter is charged. Also good. Thereby, the mirror and the shutter can be moved by driving the motor so that the first and second cams rotate in one direction.

Embodiment 1 of the present invention will be described below with reference to the drawings.

  1 and 2 are perspective views showing the configuration of the mirror box and its surroundings in the camera of this embodiment, and FIG. 3 is an exploded perspective view showing the configuration of the mirror box and its surroundings.

  In these drawings, 1 is a mirror box, 2 is a movable mirror, 3 is a movable mirror drive spring (second biasing member), 4 is a mirror drive lever (mirror drive member), 5 is a mirror drive lever return spring, 6 Is a charge lever (driven member, shutter drive member), 7 is a holding lever, 8 is a holding lever return spring, 9 is a charge arm, 10 is a holding release arm, 11 is a holding release arm return spring, 12 is a cam gear, 13 is Phase detection contact, 14 is a phase detection substrate, 15 is a first movable mirror return spring (first biasing member), 16 is a second movable mirror return spring, 17 is a motor, 18 is a reduction planetary mechanism, and 19 is a strobe. A drive gear, 20 is a shutter set member, 22 is a fixed member to which a movable mirror drive spring is attached, and 23 is a holding lever shaft.

  Here, the arrangement and assembling method of each component will be described.

The movable mirror 2 is accommodated in the mirror box 1 so as to be rotatable in the vertical direction. Reference numeral 2 a denotes a mirror driving pin that is formed integrally with the movable mirror 2 and protrudes from the inner side to the outer side of the mirror box 1. Reference numeral 2b denotes a mirror return pin that is formed integrally with the movable mirror 2 and protrudes outward from the inner side surface of the mirror box 1.
1a is an opening formed on the side surface of the mirror box 1, and has an opening area larger than the operating range of the mirror drive pin 2a and the mirror return pin 2b in the axial direction of the shaft 1b. Reference numeral 1b denotes a shaft portion that holds the charge lever 6 rotatably. Reference numerals 1c and 1d denote attachment parts to which the first movable mirror return spring 15 and the second movable mirror return spring 16 are attached.

  Further, 1p is a mirror-up positioning unit that contacts and positions the mirror drive lever 4 that moves up, and 1q is a mirror-down positioning unit that contacts and positions the mirror drive lever 4 that moves down. The shaft portion 1b, the mounting portions 1c and 1d, and the positioning portions 1p and 1q protrude from the outer side surface of the mirror box and are integrally formed with the mirror box.

  Reference numeral 6a denotes a shaft portion provided on the charge lever 6, which rotatably holds the mirror drive lever 4 and is assembled with a coil portion of the mirror drive lever return spring 5. Reference numeral 5 a denotes a fixed end of the mirror drive lever return spring 5, which is hooked on a column 1 e provided in the mirror box 1. Reference numeral 5b denotes a movable end of the mirror drive lever return spring 5, which is hooked on a spring receiving portion 4a provided on the mirror drive lever 4. Thereby, the mirror drive lever 4 receives an elastic force from the mirror drive lever return spring 5 and is urged counterclockwise.

  A coil portion of the first movable mirror return spring 15 is attached to the attachment portion 1 c of the mirror box 1. Reference numerals 15 a and 15 b denote a fixed end and a movable end of the first movable mirror return spring 15, respectively, which are hooked on a column 1 f provided on the mirror box 1 and a mirror return pin 2 b provided on the movable mirror 2. Thereby, the movable mirror 2 receives the elastic force from the first movable mirror return spring 15 and is driven to the viewfinder observation position.

  When the attaching operation of the mirror driving lever 4 and the charge lever 6 to the mirror box is completed, the fixing member 22 is attached to the end surface of the shaft portion 1b. The movable mirror drive spring 3 is assembled to the fixed member 22.

  Reference numeral 3 a denotes a fixed end of the movable mirror drive spring 3, which is hooked on a column 1 g provided on the mirror box 1. Reference numeral 3 b denotes a movable end of the movable mirror drive spring 3, which is hooked on a spring receiving portion 6 b provided on the charge lever 6. As a result, the charge lever 6 receives an elastic force from the movable mirror drive spring 3 and is urged clockwise (upward).

  The movable mirror 2 is connected to a photographing optical path from a photographing lens attached to a mount (not shown) attached to the front surface of the mirror box 1 to an imaging device (for example, a CCD sensor or a CMOS sensor) disposed behind the mirror box 1. You can move forward and backward.

  That is, the movable mirror 2 is obliquely arranged in the photographing optical path, and finder observation position for reflecting the subject light to a finder optical system (not shown) disposed above the mirror box 1 and the object light retracted outside the photographing optical path. Can be moved to and from a photographing position where an image is formed on the image sensor.

  The drive pin contact portion 4 b provided on the mirror drive lever 4 is in contact with the mirror drive pin 2 a provided on the movable mirror 2. Reference numeral 4 c denotes a mirror driving lever engaging portion that engages with the first holding lever engaging portion 7 a of the holding lever 7. Reference numeral 4 d denotes an abutting portion that abuts against the abutting portion 1 q provided in the mirror box 1.

  A concave shutter charge portion 6c provided on the charge lever 6 sandwiches and supports a drive pin 20a provided integrally with a shutter set member 20 described later. Reference numeral 6d denotes a charge lever engaging portion that engages with a charge arm engaging portion 9a of the charge arm 9 described later.

  The holding lever 7 is rotatably supported by a holding lever mounting portion 6e provided on the charge lever 6 via the holding lever shaft 23 in a state where the holding lever return spring 8 is assembled. Reference numeral 8 a denotes a fixed end of the holding lever return spring, which is hooked on a spring receiving portion 6 f provided on the charge lever 6. Reference numeral 8 b denotes a movable end of the holding lever return spring, which is hooked on a spring receiving portion 7 b provided on the holding lever 7. As a result, the holding lever 7 is urged clockwise by receiving the elastic force from the holding lever return spring 8. Reference numeral 7c denotes a second holding lever engaging portion that engages with a holding release arm engaging portion 10a provided on the holding release arm 10 described later.

  The charge arm 9 is rotatably supported by a shaft portion 1 h provided in the mirror box 1. Reference numeral 9b denotes a shaft portion that rotatably holds a later-described holding release arm 10, and a coil portion of the holding release arm return spring 11 is assembled to the shaft portion 9b. Reference numeral 11 a denotes a fixed end of the holding release arm return spring 11, which is hooked on a column 1 i provided in the mirror box 1. Reference numeral 11 b denotes a movable end of the holding release arm return spring 11, which is hooked on a spring receiving portion 10 b provided on the holding release arm 10. As a result, the holding release arm 10 is urged counterclockwise as viewed from above the mirror box 1 by the elastic force received from the holding release arm return spring 11.

Reference numeral 9 c denotes a cam pin provided on the charge arm 9, which is in contact with a charge cam 12 a (first cam) provided on the cam gear 12. Reference numeral 10 c denotes a cam pin provided on the holding release arm 10, which abuts on a holding release cam 12 b (second cam) provided on the cam gear 12.

  The cam gear 12 is rotatably held by a shaft portion 1j provided in the mirror box 1. Therefore, the charge cam 12a and the holding release cam 12b rotate around the shaft portion 1j. A gear portion 12 c provided on the cam gear 12 engages with a power transmission gear 18 a of a reduction planetary mechanism 18 described later, and rotates counterclockwise as viewed from above the mirror box 1.

  When the cam gear 12 starts rotating, the cam pin 9c moves along the outer shape of the charge cam 12a provided on the cam gear 12, and accordingly, the charge arm 9 starts rotating reciprocating movement around the shaft portion 1h. .

  Similarly, since the cam pin 10c moves along the outer shape of the holding release cam 12b provided in the cam gear 12, the holding release arm 10 starts a rotational reciprocating motion around the shaft portion 9b accordingly.

  A phase detection contact piece 13 is fixed to the cam gear 12 while maintaining a predetermined phase relationship, and is in contact with a pattern of a phase detection substrate 14 described later.

  The phase detection board 14 is fixed to a gear pressing cover (not shown) that presses each component such as a gear and an arm attached to the mirror box 1 to prevent it from falling off the mirror box 1 while maintaining a predetermined phase relationship. .

  The reduction planetary mechanism 18 is rotatably attached to a shaft portion 1n provided in the mirror box 1, and transmits the driving force of the motor 17 by decelerating and transmitting the driving force according to the rotation direction of the motor 17. The cam gear 12 or the strobe drive gear 19 described later is switched. Reference numeral 18c denotes a power transmission gear that transmits this driving force to a strobe driving gear 19 to be described later when the motor 17 is driven in the opposite direction to that during mirror driving.

  The strobe drive gear 19 is rotatably inserted into a hole 1 o provided in the mirror box 1. The strobe drive gear 19 transmits power for opening / closing and zoom driving of a strobe unit (not shown). It is also possible to transmit driving force to mechanisms other than the strobe.

  The shutter set member 20 is rotatably assembled to the rear end flange portion of the mirror box 1 and rotates downward to move the front curtain unit and the rear curtain unit of a focal plane shutter (not shown) in the charge direction. Let Further, by rotating upward from this charge completion state to a charge release state in which the charge of the front curtain unit and the rear curtain unit can be released, the front curtain and the rear curtain are kept charged by an electromagnetic magnet (not shown) From the above, the output of the electromagnetic magnet is controlled so that a predetermined shutter speed can be obtained by a control circuit (not shown), and the front curtain and rear curtain travel is completed by releasing the charge of the front curtain and rear curtain drive springs. To do.

  Next, the operation and control method of the mirror drive mechanism will be described with reference to FIGS. Here, FIG. 4 is a pattern diagram of the phase detection board 14 for detecting the rotational position of the cam gear 12. FIG. 5 is a diagram showing the phase relationship between the charge cam 12a of the cam gear 12 and the holding release cam 12b. FIG. 6 is a view when the movable mirror 2 is at the viewfinder observation position and the shutter set member 20 is at the charge completion position, that is, in a shooting standby state. FIG. 7 is a diagram when the movable mirror 2 is in the photographing position and the shutter set member 20 is in the charge release position, that is, in the mirror up state. FIG. 8 is a diagram when the movable mirror 2 is in the viewfinder observation position and the shutter set member 20 is in the charge release position, that is, in the mirror down state.

  FIG. 9 is a view of the cam gear 12, the charge arm 9, and the holding release arm 10 as viewed from above the mirror box 1 in the state shown in FIG. FIG. 10 is a view of the cam gear 12, the charge arm 9, and the holding release arm 10 as viewed from above the mirror box 1 in the state shown in FIG. FIG. 11 is a view of the cam gear 12, the charge arm 9, and the holding release arm 10 as viewed from above the mirror box 1 in the state shown in FIG.

  First, the drive control method of the cam gear 12 will be described with reference to the pattern diagram of the phase detection board 14 in FIG. When the motor 17 is rotated in a predetermined direction (for example, forward rotation), the driving force is transmitted to the gear portion 12c of the cam gear 12 via the speed reduction planetary mechanism 18, and the cam gear 12 is unidirectional in accordance with the predetermined direction. Rotate to At this time, the phase detection contact piece 13 fixed to the cam gear 12 moves on the pattern of the phase detection substrate 14 in the counterclockwise direction in FIG.

  The phase detection board 14 is formed with three conductive patterns of pattern 1 corresponding to signal 1, pattern 2 corresponding to signal 2, and GND, and the phase detection contact 13 connects the pattern 2 to the GND pattern, When it is in the range of θ1 that is not in contact with the pattern 1, the state shown in FIG. 6, that is, the movable mirror 2 is at the viewfinder observation position arranged in the photographing optical path, and the shutter set member 20 is set at the charge completion position. It will be in the state.

  Further, when the phase detection contact piece 13 connects the pattern 1 to the GND pattern and is in a range of θ2 that is not in contact with the pattern 2, the movable mirror 2 is driven from the viewfinder observation position toward the photographing position outside the photographing optical path. The shutter set member 20 is driven from the charge completion position toward the charge release position. As a result, the state shown in FIG. 7, that is, the movable mirror 2 and the shutter set member 20 are set at the photographing position and the charge release position, respectively.

  Further, when the phase detection contact piece 13 is in the range of θ3 in which both the pattern 1 and the pattern 2 are not in contact with the GND pattern, the movable mirror 2 is driven from the photographing position toward the viewfinder observation position. As a result, the state shown in FIG. 8, that is, the movable mirror 2 is set at the viewfinder observation position, and the shutter set member 20 remains at the charge release position. Further, the cam gear 12 continues to rotate, and the mirror drive mechanism returns from the state shown in FIG. 8 to the state shown in FIG.

  The output signal from the phase detection board 14 is input to a control circuit (not shown), and the control circuit rotates the motor 17 in response to the ON operation of a release switch (not shown) and the cam gear 12 corresponds to the range of θ1. The motor 17 is rotated from the position to the rotational position corresponding to the range of θ2, and the cam gear 12 is moved to the position corresponding to the range of θ2, and the rotation of the motor 17 is stopped simultaneously.

  Thereafter, the control circuit controls an electromagnetic magnet (not shown) to run a front curtain and a rear curtain (not shown) so as to obtain a predetermined shutter speed. After the shutter exposure sequence is completed, the motor 17 is rotated so that the cam gear 12 rotates from the rotational position corresponding to the range of θ2 to the rotational position corresponding to the range of θ3 and further to the rotational position corresponding to the range of θ1. Operates and prepares for the next shot.

  Next, the phase relationship between the charge cam 12a and the holding release cam 12b of the cam gear 12 will be described with reference to the cam lift arrangement diagram of the cam gear 12 shown in FIG.

  In the figure, the upper cam is the charge cam 12a, and the lower cam is the holding release cam 12b. The cam gear 12 rotates in one direction (counterclockwise direction) under the driving force of the motor 17.

  When the phase detection contact piece 13 is located in the range of θ1 on the pattern of the phase detection substrate 14, the contact point between the cam pin 9c of the charge arm 9 and the charge cam 12a, the cam pin 10c of the holding release arm 10 and the holding release cam The contact point with 12b is located in the range of θ4.

  The cam pin 9c of the charge arm 9 is in contact with the lift top surface 12a1 of the charge cam 12a, and the cam pin 10c of the holding release arm 10 is in contact with the lift bottom surface 12b2 of the holding release cam 12b. The arm 10 is in the state shown in FIG. 9, and the mirror driving mechanism is in the state shown in FIG.

  When the phase detection contact piece 13 is located in the range of θ2 on the pattern of the phase detection board 14, the contact point between the cam pin 9c of the charge arm 9 and the charge cam 12a, the cam pin 10c of the holding release arm 10 and the holding release cam The contact point with 12b is located in the range of θ5.

  The cam pin 9c of the charge arm 9 is in contact with the lift bottom surface 12a2 of the charge cam 12a, and the cam pin 10c of the holding release arm 10 is in contact with the lift bottom surface 12b2 of the holding release cam 12b. The arm 10 is in the state shown in FIG. 10, and the mirror driving mechanism is in the state shown in FIG.

  When the phase detection contact piece 13 is located in the range of θ3 on the pattern of the phase detection board 14, the contact point between the cam pin 9c of the charge arm 9 and the charge cam 12a, the cam pin 10c of the holding release arm 10 and the holding release cam The contact point with 12b is in the range of θ6.

  Even if the cam gear 12 rotates until the cam pin 10c of the holding release arm 10 moves from the lift bottom surface 12b2 of the holding release cam 12b of the cam gear 12 to contact the lift top surface 12b1, the cam pin 9c of the charge arm 9 remains The charge cam 12a remains in contact with the lift bottom surface 12a2, the charge arm 9 and the holding release arm 10 are in the state shown in FIG. 11, and the mirror drive mechanism is in the state shown in FIG.

  When the cam gear 12 further rotates to the range of θ1, the charge arm 9 and the holding release arm 10 return to the state of FIG. 9, and the mirror drive mechanism returns to the state of FIG. 6 to prepare for the next shooting.

  Next, the operation of the drive mechanism when the drive mechanism shifts from the state shown in FIGS. 6 and 9 to the state shown in FIGS. 7 and 10 will be described.

  In the state shown in FIG. 6, the charge lever 6 that drives the shutter member 20 by the charge arm engagement portion 9 a of the charge arm 9 is driven in the counterclockwise direction, and therefore is movable by the spring receiving portion 6 b of the charge lever 6. The movable end 3b of the mirror drive spring 3 is pushed to the right side. Thereby, the movable mirror drive spring 3 is charged so that the charge lever 6 can be driven in the clockwise direction, and the shutter member 20 can be set at the charge completion position. At this time, the first movable mirror return spring 15 is not yet charged.

  In this state, when the cam gear 12 rotates counterclockwise in FIG. 9, the lift top surface 12a1 of the charge cam 12a contacting the cam pin 9c of the charge arm 9 is interrupted, and the charged movable mirror drive spring 3 is charged. The charge lever 6 is driven in the clockwise direction in FIG. At this time, since the charge lever engaging portion 6d of the charge lever 6 and the charge arm engaging portion 9a of the charge arm 9 are engaged, the charge arm 9 moves the shaft portion 1h of the mirror box 1 as shown in FIG. The cam pin 9c of the charge arm 9 contacts the lift bottom surface 12a2 of the charge cam 12a.

  When the charge lever 6 is driven from the state shown in FIG. 6 to the state shown in FIG. 7, the shutter charge portion 6 c of the charge lever 6 rotates the drive pin 20 a of the sandwiched shutter set member 20 upward, and the shutter set The member 20 is rotated from the charge completion position of FIG. 6 to the charge release position of FIG.

  Further, at the same time as the shutter set member 20 is rotated from the charge completion position to the charge release position, the first holding lever engaging portion 7 a formed on the holding lever 7 is engaged with the mirror driving lever provided on the mirror driving lever 4. By engaging with the joint portion 4 c, the mirror drive lever 4 is coupled to the charge lever 6 and is driven clockwise together with the charge lever 6 against the spring force of the mirror drive lever return spring 5.

  As the mirror drive lever 4 rotates in the clockwise direction, the drive pin contact portion 4b of the mirror drive lever 4 contacts the mirror drive pin 2a of the movable mirror 2. Thereby, the mirror drive lever 4 rotates the movable mirror 2 from the viewfinder observation position toward the photographing position shown in FIG. 7 via the mirror drive pin 2a. Then, when the abutting portion 6g of the charge lever 6 comes into contact with the mirror up positioning portion 1p of the mirror box 1, as shown in FIG. 7, the movable mirror 2 is at the photographing position, and the shutter set member 20 is released from the charge. Move to position. In the state shown in FIG. 6, since the mirror return pin 2b of the movable mirror 2 and the movable end 15b of the first movable mirror return spring 15 are in contact, the movable mirror 2 moves (moves upward) to the photographing position. The first movable mirror return spring 15 is charged. Here, in the state shown in FIG. 7, since the holding lever engaging portion 7a of the holding lever 7 is engaged with the mirror drive lever engaging portion 4c of the mirror driving lever 4, the mirror driving lever 4 is driven by the mirror. It is possible to prevent the lever return spring 5 from rotating counterclockwise by the biasing force of the lever return spring 5. As a result, the first movable mirror return spring 15 can be held in a charged state.

  Next, the operation of the mirror drive mechanism when shifting from the state shown in FIGS. 7 and 10 to the state shown in FIGS. 8 and 11 will be described.

  When the cam gear 12 rotates counterclockwise from the state shown in FIG. 10, the cam pin 10c of the holding release arm 10 in contact with the lift bottom surface 12b2 of the holding release cam 12b of the cam gear 12 in FIG. It rides on and contacts the lift top surface 12b1. When the cam pin 10c of the holding release arm 10 moves from the lift bottom surface 12b2 of the holding release cam 12b to the lift top surface 12b1, the holding release arm 10 rotates clockwise about the shaft 1h of the mirror box 1 as the rotation center. Then, it moves to the state shown in FIG. 11 against the urging force of the holding release arm return spring 11.

  When the holding release arm 10 rotates clockwise, the holding release arm engaging portion 10a of the holding releasing arm 10 moves the second holding lever engaging portion 7c of the holding lever 7 downward in FIG.

  When the second holding lever engaging portion 7 c of the holding lever 7 moves downward in FIG. 11, the holding lever 7 resists the urging force of the holding lever return spring 8 and the holding lever mounting portion of the charge lever 6. 6e is rotated counterclockwise about the rotation axis. When the cam gear 12 rotates to the state shown in FIG. 11, the holding lever 7 rotates to the state shown in FIG.

When the holding lever 7 rotates to the state shown in FIG. 8 in this way, the engagement of the holding lever 7 with the mirror drive lever 4 is discontinued, and the mirror drive lever 4 is moved by the urging force of the mirror drive lever return spring 5. It rotates counterclockwise around the shaft 1b of the box 1. Mirror driving lever 4 that initiated this rotation is stopped by the abutting portion 4d abuts against the mirror-down positioning portion 1q of the mirror box 1, rotated to the state of FIG.

  Further, when the mirror drive lever 4 rotates counterclockwise, the mirror drive pin contact portion 4b that is in contact with the mirror drive pin 2a is detached therefrom, so that the charged first movable mirror return spring 15 and Due to the biasing force of the second movable mirror return spring 16, the movable mirror 2 rotates in the clockwise direction and moves from the photographing position in FIG. 7 to the viewfinder observation position in FIG.

  Next, the operation of the mirror drive mechanism when shifting from the state shown in FIGS. 8 and 11 to the state shown in FIGS. 6 and 9 will be described.

  When the cam gear 12 rotates counterclockwise from the state shown in FIG. 11, the lift top surface 12 b 1 of the holding release cam 12 b of the cam gear 12 is interrupted and is biased by the holding release arm return spring 11. The ten cam pins 10c abut against the lift bottom surface 12b2 of the holding release cam 12b. When the cam pin 10c of the holding release arm 10 contacts the lift bottom surface 12b2 of the holding release cam 12b, the holding release arm 10 moves to the position shown in FIG.

  When the cam gear 12 rotates counterclockwise from the state shown in FIG. 11, the cam pin 9c of the charge arm 9 that is in contact with the lift bottom surface 12a2 of the charge cam 12a of the cam gear 12 is lifted from the lift top surface of the charge cam 12a. 12a1 contacts. When the cam pin 9c of the charge arm 9 enters the lift top surface 12a1 of the charge cam 12a, the charge arm 9 rotates and moves to the position shown in FIG.

  When the charge arm 9 rotates counterclockwise, the charge arm engaging portion 9a of the charge arm 9 engages with the charge lever engaging portion 6d of the charge lever 6 and rotates the charge lever 6 counterclockwise. . As the charge lever 6 rotates counterclockwise, the movable mirror driving spring 3 in which the movable end 3b and the fixed end 3a are hung on the spring receiving portion 6b of the charge lever 6 and the column 1g of the mirror box 1 is charged. Is done.

  At the same time, since the shutter charge portion 6c of the charge lever 6 pushes down the drive pin 20a of the shutter set member 20, the shutter set member 20 rotates toward the charge completion state shown in FIG. When the cam pin 9c of the charge arm 9 contacts the lift top surface 12a1 of the charge cam 12a of the cam gear 12, the shutter set member 20 reaches the charge completion position, and the front curtain unit and the rear curtain unit (not shown) are not shown. The electromagnetic magnet is held in the charge complete state by the attractive force.

  Further, the first holding lever engaging portion 7a of the holding lever 7 is in sliding contact with the mirror driving lever engaging portion 4c of the mirror driving lever 4, and the first holding lever engaging portion 7a of the mirror driving lever engaging portion 4c. At the moment when it comes out to the right, the holding lever 7 rotates in the clockwise direction by the urging force of the holding lever return spring 8. Thereby, the first holding lever engaging portion 7a is pushed down, and the first holding lever engaging portion 7a of the holding lever 7 pushes the mirror driving lever engaging portion 4c of the mirror driving lever 4 as shown in FIG. Move to a lockable position.

  Thus, the state shown in FIG. 6 is shifted to the state shown in FIG. 7, and then the state shown in FIG. 8 is changed to return to the state shown in FIG. 6. In other words, the cam gear 12 is rotated once, thereby taking one image. The operation ends.

  In addition, since the movable mirror 2 and the shutter member 20 can be driven by rotating the cam gear 12 in one direction, the drive control of the motor 17 can be simplified, and a mirror drive mechanism that takes load distribution into consideration can be provided. realizable.

Furthermore, since load distribution is taken into consideration, it is possible to provide a mirror driving device that consumes less power even when the mirror and the shutter are driven with the same driving force.

  In addition, the charge cam 12a and the holding release cam 12b are configured as a single member and driven in one direction around the same axis so that the mirror and the shutter driving mechanism can be driven, so that the driving efficiency is high, Further, it is possible to prevent a phase shift between the two cams due to an assembly error. As a result, it is possible to provide a mirror driving device with low power consumption and high accuracy.

The perspective view of the mirror box periphery in the camera which is an Example of this invention 1 is a perspective view around a mirror box in a camera that is an embodiment of the present invention. The exploded perspective view around a mirror box. The pattern diagram of the phase detection base | substrate for detecting the rotation phase of the cam gear in an Example. The figure which showed the mirror drive cam and holding | maintenance release cam of the cam gear in an Example. The movable mirror in the example is in the viewfinder observation position, The side view when a movable mirror in an example is in a photographing position and a shutter set member is in a jersey release position. The side view when the movable mirror in an Example exists in a finder observation position, and a shutter set member exists in a charge release position. The figure which showed the position of the cam gear in the state of FIG. 6, a charge arm, and a holding release arm from the mirror box upper part. The figure which showed the position of the cam gear in the state of FIG. 7, a charge arm, and a holding release arm from the mirror box upper part. The figure which showed the position of the cam gear in the state of FIG. 8, a charge arm, and a holding release arm from the mirror box upper part.

Explanation of symbols

1: mirror box 2: movable mirror 3: movable mirror drive spring 4: mirror drive lever 5: mirror drive lever return spring 6: charge lever 7: holding lever 8: holding lever return spring 9: charge arm 10: holding release arm 11 : Holding release arm return spring 12: Cam gear 13: Phase detection contact piece 14: Phase detection board 15: First movable mirror return spring 16: Second movable mirror return spring 17: Motor 18: Deceleration planetary mechanism 19: Strobe drive gear 20 : Shutter set member 22: Fixed member 23: Holding lever shaft

Claims (10)

A mirror movable to a first position arranged in the imaging optical path and a second position retracted outside the imaging optical path;
A first biasing member that generates a biasing force that drives the mirror from the second position to the first position;
A second biasing member that generates a biasing force that drives the mirror from the first position to the second position;
A holding member capable of holding the first biasing member in a charged state;
A first cam having a charge portion for charging the second biasing member and a release portion for releasing the charge of the second biasing member;
A second cam for releasing the holding by the holding member;
A motor that drives both the first and second cams;
The mirror driving apparatus characterized in that the motor drives the first and second cams in only one direction.   The said 2nd biasing member charges the said 1st biasing member, when driving the said mirror to the said 2nd position from the said 1st position, The said 1st biasing member is characterized by the above-mentioned. Mirror drive device. Having a shutter,
3. The mirror driving device according to claim 1, wherein the first cam charges the shutter when the second urging member is charged by the charging unit. 4. Having a shutter,
The second urging member drives the shutter from a charged state to a state allowing charge release when driving the mirror from the first position to the second position. Item 4. The mirror driving device according to any one of Items 1 to 3.   5. The apparatus according to claim 1, further comprising a driven member that includes the holding member and is driven by the second urging member in a state of being connected to the mirror by the holding member. Mirror drive device. Having a shutter,
The mirror driving apparatus according to claim 5, wherein the driven member drives the shutter.   The mirror driving device according to any one of claims 1 to 6, wherein the first and second cams are driven in the same direction.   The mirror driving device according to any one of claims 1 to 6, wherein the first and second cams are driven to rotate about the same axis. A mirror movable with respect to the photographing optical path;
A mirror driving member movable to a first position where the mirror is disposed in the photographing optical path and a second position where the mirror is retracted out of the photographing optical path;
A first biasing member that generates a biasing force that drives the mirror driving member from the second position to the first position;
A shutter;
A shutter driving member for driving the shutter;
A connecting member provided in the shutter driving member and connecting the mirror driving member to the shutter driving member;
A second urging member that generates an urging force for driving the shutter driving member and drives the mirror driving member from the first position to the second position via the shutter driving member and the connecting member; ,
A first cam having a charging portion that drives the shutter driving member in a direction in which the second urging member is charged and a release portion that allows driving of the shutter driving member by the second urging member;
A second cam for releasing the connection of the mirror driving member by the connecting member at the second position;
A motor that drives both the first and second cams;
The mirror driving apparatus characterized in that the motor drives the first and second cams in only one direction.   An imaging apparatus comprising the mirror driving device according to claim 1.

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