JP4401765B2 - Shutter for digital camera - Google Patents

Description

  The present invention relates to a shutter for a digital camera suitable for use in a digital still camera, a digital video camera capable of taking a still image, an information terminal device with a camera, and the like.

In the case of a camera equipped with a solid-state imaging device, a still image with good image quality can be obtained by providing a shutter device. Such a shutter device is of course only a shutter device, but may be configured as a unit together with the aperture device (see Patent Document 1). Further, in most cases, such shutter devices have opened and closed shutter blades by an electromagnetic actuator such as a motor in most cases. However, when the electromagnetic actuator has a unique configuration, the shutter blade closing operation start position (hereinafter referred to as the initial position) may not be determined. Therefore, in the case of such a shutter device, the position of the shutter blade is detected by a photo sensor every time shooting is performed, and after having been reliably returned to the initial position, the closing operation is started. It is described in Patent Document 2.
JP 2003-131285 A JP 2001-183718 A

  By the way, in a shutter for a digital camera, a shutter blade is in an initial position and an exposure opening is fully opened before photographing, so that a subject image can be observed with a liquid crystal monitor. In addition, shooting is started by releasing the charge accumulated so far in the solid-state imaging device with the shutter blades fully opened, and newly accumulating the charges, and the shutter blades close the exposure opening. It ends by finishing. When the imaging information is transferred to the storage device in the closed state, the shutter blade is returned to the initial position. For this reason, if the time from when the electromagnetic actuator is energized until the shutter blade starts closing the exposure opening deviates from the normal (reference) time, proper exposure cannot be obtained. Further, when the shutter blades once close the exposure opening and then bounce and temporarily open a part of the exposure opening, a smear phenomenon becomes remarkable as is well known, and a high-quality image cannot be obtained.

  For this reason, in the design stage, the best care is taken to prevent such a situation from occurring, but there are still various problems in production. That is, the speed at which the shutter blade closes the exposure opening is preferably constant and high, but the initial speed is inevitably slow due to factors such as the startability of the electromagnetic actuator and the friction of the blade. For this reason, the shutter blades are designed not to start closing the exposure opening immediately after starting from the initial position but to start closing after running (running) for a short distance. However, tolerances are set for the startability and driving force of the electromagnetic actuator. In addition, tolerances are also defined for the size and weight of the shutter blades, and there are tolerances in the assembling part of the base plate and the connecting part with the electromagnetic actuator.

  For this reason, the time from the start of energization to the electromagnetic actuator until the shutter blade starts closing the exposure opening differs for each manufactured shutter, and so-called individual differences occur. Therefore, in order to obtain an appropriate exposure amount, it is also important that the shutter blades always start the closing operation from the initial position as detected by the photosensor as described in Patent Document 2. However, apart from that, it is also important to be able to appropriately handle the individual differences as described above during production and repair.

  On the other hand, the faster the shutter blade closing operation is, the better, so that the unevenness of exposure does not become conspicuous, and in order not to give a sense of incongruity to the observation on the liquid crystal monitor. However, if the closing operation is speeded up, the bounce of the shutter blades at the time of stopping may increase accordingly. If a part of the exposure opening is temporarily opened due to bouncing and the solid-state imaging device is re-exposed, overexposure and uneven exposure occur, and a high-quality image cannot be obtained. For this reason, design is usually performed in advance so that such a situation does not occur. However, there are some designs that have a high probability of re-exposure due to restrictions on the size and arrangement conditions of the components. There are times when you have to do. Therefore, in the case of such a design, it is necessary to be able to appropriately cope with a product in which re-exposure occurs due to bounce at the time of manufacture or repair.

  The present invention has been made to solve such a problem, and an object of the present invention is to appropriately detect the time from when the electromagnetic actuator is energized until the shutter blade starts closing the exposure opening. Further, it is an object of the present invention to provide a shutter for a digital camera having a suitable configuration capable of appropriately detecting the bounce of the shutter blade at the end of the closing operation.

In order to achieve the above object, each of the shutters for a digital camera of the present invention has an opening for a photographing optical path, restricts the exposure opening at least one of the openings, and between them. Two ground plates constituting a blade chamber, at least one shutter blade disposed in the blade chamber for opening and closing the exposure opening, and attached to one of the ground plates, A shutter driving electromagnetic actuator for causing the shutter blade to open and close the exposure opening, and a first photo for detecting the first position of the shutter blade immediately before starting to close the exposure opening after starting the operation from the initial position. open and the sensor, a portion of the shutter blade stage a first signal generated by the bounce after closing the exposure opening temporarily said exposure opening for closing the exposure opening Step a second signal generated by the first signal is said second signal is ignored to as and a second photosensor which is a signal obtained by detecting a second position of the shutter blade. The first photo sensor and the second photo sensor may be a single photo sensor.

  In addition, when one photosensor is used in this way, it is further attached to at least one diaphragm blade disposed in the blade chamber and restricting a diaphragm opening smaller than the exposure opening, and one of the ground plates. An aperture driving electromagnetic actuator that moves the aperture blade back and forth from the initial position where the aperture blade is retracted from the exposure aperture, and the one photosensor is configured to move the first aperture of the shutter blade. You may make it detect at least one of a position and the said 2nd position, and the initial position of the said aperture blade.

  Further, in that case, the shutter chamber is disposed between the two ground plates, the shutter chamber is formed between the two ground plates, the throttle chamber is formed between the other ground plates, and the two ground plates are provided. An intermediate plate having an opening that restricts the exposure opening by at least one of the openings, and the shutter blades are disposed in the shutter chamber, An aperture ring that is reciprocally rotated around the exposure aperture by the aperture driving electromagnetic actuator, and a plurality of aperture blades that are simultaneously reciprocated in the same direction by the rotation of the aperture ring, and One photosensor may indirectly detect the initial position of the aperture blade by detecting the position of the aperture ring.

  Since the shutter for the digital camera of the present invention can appropriately detect the time from when the electromagnetic actuator is energized until the shutter blade starts closing the exposure opening, the exposure control variation caused by the individual difference of the shutter device is At the time of manufacture or repair, it is possible to adjust by changing the relative timing of the start of charge re-accumulation for the solid-state imaging device and the start of energization of the electromagnetic actuator at the time of shooting. The ability to perform such adjustment is extremely effective particularly when the energization start timing for the electromagnetic actuator has a specification that precedes the charge accumulation start timing for the solid-state imaging device. Further, according to the present invention, there is an effect that it is possible to appropriately detect the bounce of the shutter blade at the end of the closing operation. Furthermore, when unitized with the diaphragm device, it is possible to regulate the initial position of the diaphragm blades.

  Embodiments of the present invention will be described with reference to three illustrated examples. In addition, those embodiments are all configured to be suitable for use in a digital still camera, and in the first and second embodiments, only the shutter device is configured as a unit. In the third embodiment, both the shutter device and the aperture device are configured as one unit. 1 to 5 are for explaining the first embodiment, FIGS. 6 to 8 are for explaining the second embodiment, and FIGS. 9 to 15 are for explaining the third embodiment. belongs to.

  First, the first embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a plan view showing a state in which the shutter blades are in the initial position, FIG. 2 is a cross-sectional view of the main part, and FIG. FIG. 4 is a plan view showing a state where the shutter blade closes the exposure opening and abuts against the stopper, and FIG. 4 is a plan view showing a state where the shutter blade bounces from the state of FIG. FIG. 5 is a timing chart for explaining the timing when the shutter blades start to close. In FIGS. 1, 3, and 4, only the rotor of the known actuator shown in FIG. 2 is shown by a two-dot chain line. Moreover, in FIG.1, FIG.3, FIG.4, it has shown in the state which cut | disconnected some main ground plates.

  First, the configuration of this embodiment will be described with reference to FIGS. The main base plate 1 and the auxiliary base plate 2 are made of synthetic resin, are attached to each other by means not shown, and constitute a blade chamber between them. The ground planes 1 and 2 have substantially the same planar shape, and circular openings 1a and 2a centering on the optical axis are formed in the center. Although it is not clear on the drawing, the opening 1a is slightly smaller in diameter than the opening 2a and regulates the exposure opening. However, it goes without saying that the diameter of the opening 2a may be reduced to restrict the exposure opening.

  Two shafts 1b and 1c and four stoppers 1d, 1e, 1f, and 1g are provided on the surface of the main base plate 1 on the blade chamber side, and the shutter blade 3 is rotatably attached to the shaft 1b. The shutter blade 4 is rotatably attached to the shaft 1c. Each of the shutter blades 3 and 4 is formed with a long hole, but since it is a well-known thing, it is not given a reference numeral so that the drawing can be easily seen. Further, the main base plate 1 is formed with a long hole 1h in an arc shape, and the auxiliary base plate 2 has a long groove 2b (FIG. 2) formed as a recess having the same shape on the surface of the blade chamber facing the long hole 1h. ) Is formed. Furthermore, two square holes are formed in the main base plate 1, and photosensors 5 and 6 are embedded therein, and the auxiliary base plate 2 has blades facing the photosensors 5 and 6. A depression is formed on the chamber side surface, and reflection sheets 7 and 8 (FIG. 2) are attached thereto.

  These photosensors 5 and 6 are reflection type photosensors, also called photoreflectors, and are of a type in which light received from the light emitting portion and reflected by the reflection sheets 7 and 8 is received by the light receiving portion. However, in the following description, a signal when the outgoing light is received by the light receiving unit is referred to as an H level signal, and a signal when the outgoing light is not received is referred to as an L level signal. As the photosensor, a direct-type photosensor as used in Example 3 to be described later is also known, but in this example, the photosensors 5 and 6 are used as such a direct-type photosensor. It can be replaced. Even in the case of such a direct-light photosensor, the signal when the outgoing light is received by the light receiving unit is an H level signal, and the signal when no light is received is an L level signal. .

  Actuators for the shutter blades 3 and 4 are attached to the surface of the main base plate 1 outside the blade chamber. The actuator of the present embodiment is a current control type motor generally called a moving magnet type motor or the like, and a rotor made of a permanent magnet corresponds to a direction of energization to the stator coil. It is a motor that reciprocates only within an angular range. Also in this type of motor, various types of motors are known depending on the configuration of the stator, but the motor used in this embodiment is also described in Patent Document 2. The one of the best known type. Therefore, although it is not necessary to explain again, it will be briefly described mainly with reference to FIG.

  The rotor 9 is supported by a first stator frame 10 that is shaped like a cup, and a second stator frame 11 that has a substantially flat plate shape. It winds so that the bearing part of the stator frames 10 and 11 may be enclosed, and the cylindrical yoke 13 is fitted by the outer side. Further, in the second stator frame 11, a long hole 11a having a shape similar to that of the long hole 1h is formed at a position facing the long hole 1h of the main ground plate 1. The second stator frame 11 is attached to the main base plate 1 with two screws 14 and 15. The rotor 9 is made of a permanent magnet, but the rotating shaft and the output pin 9a formed so as to be parallel to the rotating shaft are made of synthetic resin, and the output pin 9a is the second pin. Insert the long hole 11a of the stator frame 11 and the long hole 1h of the main base plate 1 into the long holes of the shutter blades 3 and 4 in the blade chamber, and insert the tip into the long groove 2b of the auxiliary base plate 2. Yes.

  In this type of motor, when the coil 12 is not energized, the stop position of the rotor 9 becomes extremely unstable unless some measure is taken. Therefore, in the case of the present embodiment, a magnetic rod (also referred to as an iron pin) is embedded at a predetermined position of the first stator 10 so as to face the outer peripheral surface of the rotor 9. The stationary state of the rotor 9 is stabilized by the suction force acting between the two and the like, but such a configuration is well known and is omitted in the drawing.

  Next, the operation of this embodiment will be described mainly with reference to FIGS. 1 and 3 to 5. FIG. 1 shows a state in which the camera is turned on before photographing and a subject image can be observed with a liquid crystal monitor. At this time, the rotor 9 is given a force that rotates clockwise by an attractive force acting between the rotor 9 and the magnetic rod (iron pin) (not shown). Since it is in contact with the stoppers 1d and 1e, it cannot rotate, and this state is maintained. At this time, the photosensors 5 and 6 do not block the optical path of the emitted light by the shutter blade 3, and both emit a signal of H level.

  When shooting, when a release button is pressed, exposure for shooting is started by discharging the charge accumulated in the solid-state imaging device by a signal from the exposure control circuit (A in the timing chart of FIG. 5). ), Electric charges are newly accumulated in the solid-state imaging device. Then, when a predetermined time determined by the measurement result of the photometry circuit elapses, energization in the positive direction is started to the motor coil 12 (time B in FIG. 5). Thereby, the rotor 9 is rotated counterclockwise, and from each initial position, the shutter blade 3 is rotated counterclockwise and the shutter blade 4 is rotated clockwise. Thus, when the shutter blades 3 and 4 are simultaneously rotated in opposite directions and immediately before the opening 1a starts to close, the tip of the shutter blade 3 blocks the optical path of the photosensor 5. Therefore, the photosensor 5 emits an L level signal from that moment (time point C in FIG. 5).

  By the way, as already described, the time required from the start of energization to the coil 12 until the shutter blades 3 and 4 start to close the opening 1a is not uniform in manufacturing, and individual differences occur. End up. If the time is longer than the design reference time (the time from B to C in FIG. 5) (the time from B to E in FIG. 5), the overexposure is made by the amount marked with x. If it is short (time from B to D in FIG. 5), the exposure will be underexposed by the amount of □. Therefore, in the case of the present embodiment, at the time of manufacture, the time from the start of energization to the coil 12 until the photosensor 5 emits an L level signal is measured, and in FIG. If it occurs, the time from the start of charge re-accumulation to the solid-state imaging device (time A) performed after the discharge of the charge as described above to the start of energization of the coil 12 is set between D and C. In contrast, when the L level signal is generated at the time point E, for example, by shortening the time between C and E, the above design reference time can be obtained. In addition, depending on the camera specifications, if the camera deviates from the above design reference time after using the camera, it will warn that proper exposure cannot be obtained. It is also possible.

  Thus, after the shutter blade 3 generates an L level signal to the photosensor 5, the shutter blades 3 and 4 close the opening 1a. The H level signal is generated from the photosensor 6 and the L level signal is generated from the photosensor 6. However, any of those signals is ignored. After that, when the opening 1a is closed, an H level signal is generated again from the photosensor 6, but this signal is also ignored. Then, after closing the opening 1a, the shutter blades 3 and 4 come into contact with the stoppers 1f and 1g and stop. This state is the state shown in FIG. In this state, the imaging information accumulated in the solid-state imaging device is immediately transferred to the storage device.

  By the way, the shutter blades 3 and 4 finish the closing operation as described above. However, since the operation is performed at a high speed, when the shutter blades 3 and 4 come into contact with the stoppers 1f and 1g, the design is assumed in advance due to individual differences. You may bounce larger than you expected. FIG. 4 shows the state of bouncing larger than expected in such a way, exaggerated much more than actual. In such a state, a part of the opening 1a is temporarily opened, and the solid-state imaging device is re-exposed. Therefore, before the re-exposure is transferred to the storage device as described above. When it occurs, it may cause overexposure and uneven exposure, and a high-quality image cannot be obtained.

  However, in the case of the present embodiment, as can be seen from FIG. 4, if the second L signal of the photosensor 6 is generated before starting the energization in the reverse direction to the coil 12 to be described later, The situation can be detected, and measures can be taken by replacing one shutter blade 3 or the like. In this embodiment, the closing operation of the shutter blades 3 and 4 is stopped by contacting the stoppers 1f and 1g. However, the output pin 9a is not provided with the stoppers 1f and 1g. The same can be said for the case of stopping by contacting the edge of the hole 1h.

  In this way, when the shutter blades 3 and 4 are closed and the imaging information is transferred to the storage device, the coil 12 is energized in the direction opposite to the above in the state of FIG. . Thereby, the rotor 9 rotates clockwise and causes the shutter blades 3 and 4 to open. However, all signals from the photosensors 5 and 6 generated at this time are ignored. The shutter blades 3 and 4 are stopped at their initial positions after contacting the stoppers 1d and 1e after the opening 1a is fully opened. After that, when the coil 12 is de-energized, the state shown in FIG. It has returned.

  Next, Embodiment 2 will be described with reference to FIGS. 6 to 8. FIG. 6 is a plan view showing a state in which the shutter blades are in the initial position, and FIG. 7 shows the shutter blades closing the exposure opening. FIG. 8 is a plan view showing a state where the shutter blade is in contact with the stopper, and FIG. 8 is a plan view showing a state where the shutter blades bounce from the state shown in FIG. Moreover, these drawings are shown in a state in which a part of the main ground plate 1 is cut in the same manner as in FIGS. 1, 3, and 4. By the way, the configuration of the present embodiment can be understood by comparing FIGS. 6 to 8 with FIGS. 1, 3 and 4 described above. Whereas the sensors 5 and 6 are attached, the present embodiment is different in that only one reflection type photosensor 16 is attached and the outer shape of the shutter blades 3 and 4 is slightly different. Can be said to be exactly the same as in the first embodiment. Therefore, substantially the same members and parts as those in the first embodiment are denoted by the same reference numerals, and a detailed description of the configuration will be omitted.

  Therefore, the operation of the present embodiment will be described, but the description overlapping with the operation description of the first embodiment will be simplified. FIG. 6 shows a state in which a subject image can be observed with a liquid crystal monitor. The photosensor 16 emits an H level signal without blocking the optical path of the emitted light by the shutter blade 3. When shooting, when the release button is pressed, the exposure from the exposure control circuit releases the charge that has been stored in the solid-state image sensor until the exposure for shooting starts. Will accumulate. When a predetermined time elapses, energization in the positive direction is started with respect to the motor coil 12, and the rotor 9 is rotated counterclockwise.

  Thereby, the shutter blades 3 and 4 are rotated in opposite directions from the initial position, and the closing operation is started. Then, immediately before the shutter blades 3 and 4 start to close the opening 1a, the tip of the shutter blade 3 blocks the optical path of the photosensor 16, so that the photosensor 16 outputs an L level signal from that moment. Will be emitted. Accordingly, at the time of manufacturing, the time from the start of energization to the coil 12 until the photosensor 16 emits an L level signal is measured. By adjusting the time from the start of re-accumulation to the start of energization of the coil 12, the design reference time is obtained.

  In this way, after the shutter blade 3 generates an L level signal in the photosensor 16, the shutter blades 3 and 4 close the opening 1a. When the opening 1a is closed, an H level signal is generated again from the photosensor 16, but the signal is ignored. Then, after closing the opening 1a, the shutter blades 3 and 4 come into contact with the stoppers 1f and 1g and stop, but this state is the state shown in FIG. However, when the shutter blades 3 and 4 are in contact with the stoppers 1f and 1g in this manner, as shown in FIG. 8, the shutter blades 3 and 4 bounce larger than expected due to individual differences. It may end up. Therefore, in the case of the present embodiment, the occurrence of such a situation can be detected by the second generation of the L signal of the photosensor 16 before the coil 12 described later is energized in the reverse direction. It is possible to take measures such as replacing the shutter blade 3.

When the shutter blades 3 and 4 are closed, the imaging information is transferred to the storage device in the state shown in FIG. When the transfer ends, the coil 12 is energized in the opposite direction to the above, and the rotor 9 is rotated clockwise. As a result, the shutter blades 3 and 4 perform an opening operation to fully open the opening 1a, and then come into contact with the stoppers 1d and 1e to be stopped at the initial position. Thereafter, when the power supply to the coil 12 is cut off, the state shown in FIG. 6 is restored. As described above, the present embodiment is slightly larger in the shape of the shutter blades 3 and 4 than the first embodiment, but has an advantage that only one photosensor is required.

  Next, Embodiment 3 will be described with reference to FIGS. 9 to 15. In this embodiment, the shutter device and the diaphragm device are configured as one unit. FIG. 9 is a plan view showing a state in which the shutter blades and the diaphragm blades are in the initial positions, and FIG. 10 is a cross-sectional view of the main part of FIG. Moreover, FIGS. 11-15 is for demonstrating the action | operation from the state of FIG. The configuration of the shutter device, which is a part of the configuration of this embodiment, is almost similar to the configuration of the above two embodiments. For this reason, constituent members of the shutter device are denoted by the same reference numerals for substantially the same members and parts as those of the above-described two embodiments, and only different points will be described.

  First, the configuration of this embodiment will be described mainly with reference to FIGS. The main ground plate 21 and the auxiliary ground plate 22 of the present embodiment are made of synthetic resin, and a thin intermediate plate 23 is disposed between them. These three members are attached by means (not shown), constitute a diaphragm chamber between the main base plate 21 and the intermediate plate 23, and constitute a shutter chamber between the intermediate plate 23 and the auxiliary base plate 22. . Further, circular openings 21a, 22a, 23a centering on the optical axis are formed at the center of these three parts, but the diameter of the opening 23a is the smallest, and the exposure opening (maximum aperture opening). ) Is regulated. However, it goes without saying that the opening 21a or the opening 22a may be made to restrict the exposure opening.

  Therefore, next, a configuration related to the shutter device will be described. Two shafts 21b and 21c are provided on the surface of the main base plate 21 on the blade chamber side and pass through the intermediate plate 23. In the shutter chamber, the shutter blade 3 is rotatably attached to the shaft 21b. The shutter blade 4 is rotatably attached to the shaft 21c. The shutter blades 3 and 4 of the present embodiment have shapes different from those of the first and second embodiments, but are substantially the same, and the output pins 9a of the rotor 9 are respectively fitted. It has a long hole. In FIG. 10, illustration of the shutter blade 3 is omitted. The main base plate 21 is formed with an arc-shaped long hole 21d (FIG. 10) having the same shape as the long hole 1h in the first and second embodiments, and the intermediate plate 23 is opposed to the long hole 21d. A long hole 23b (FIG. 10) having the same shape is formed in the region, and a long groove 22b (FIG. 10) is formed in the auxiliary ground plate 22 as a recess having the same shape on the surface facing the long hole 23b. .

  In the case of the present embodiment, the main base plate 21 is not provided with a stopper for contacting the shutter blades 3 and 4, and the rotation of the shutter blades 3 and 4 causes the output pin 9a of the rotor 9 to move into the long hole 21d. It is made to stop by abutting on both ends. One photosensor 24 is attached between the main ground plate 21 and the auxiliary ground plate 23. The photosensor 24 is a direct-type photosensor also called a photo interrupter, and the tip of the shutter blade 4 passes between the light emitting portion and the light receiving portion. Therefore, in the case of a present Example, the reflection sheets 7 and 8 in Example 1, 2 are not provided. The actuator for driving the shutter is attached to the surface of the main base plate 21 outside the blade chamber, and the configuration thereof is substantially the same as that described in the first embodiment. Therefore, although description of the configuration is omitted, the mounting screws 14 and 15 are not shown in FIGS. 9 and 11 to 15.

  Next, a configuration related to the diaphragm device will be described. In the aperture chamber, an aperture ring 25 and seven aperture blades 26 (only one is indicated except for FIG. 10) are arranged. Among them, the diaphragm ring 25 is formed with seven cam grooves 25a (only one is labeled) at substantially equal angular intervals, and a tooth portion 25b is formed in a predetermined angular range on the outer periphery. A light shielding portion 25c is formed at a predetermined position. The light shielding part 25c enters and exits between the light emitting part and the light receiving part of the photosensor 24. The diaphragm blades 26 all have the same shape, and have a shaft pin 26 a and an engagement pin 26 b on the main ground plate 21 side, and the shaft pin 26 a is rotated into a hole formed in the ground plate 21. The engagement pin 26 b is inserted into the cam groove 25 a of the aperture ring 25.

  The diaphragm driving actuator in this embodiment is a step motor known in Japanese Patent Laid-Open No. 2002-131802, etc., and its configuration will be briefly described. The rotor 27 includes a shaft portion 27a made of synthetic resin, a cylindrical permanent magnet 27b attached to the shaft portion 27a, and an output gear 27c formed integrally with the shaft portion 27a. It is rotatably attached to a shaft 21e that is erected on the main plate 21. The permanent magnet 27b is magnetized with four poles in the radial direction. The stator is composed of two yokes 28 and 29 attached to the main base plate 21 by means not shown, and coils 30 and 31 wound around one leg of each. In the yokes 28 and 29, the tip ends of the two leg portions are used as magnetic pole portions, which are inserted into holes formed in the main base plate 21, and are opposed to the circumferential surface of the permanent magnet 27b. Further, the reduction gear 32 is a two-stage gear composed of a parent gear and a child gear, and is rotatably attached to a shaft 21 f provided on the main base plate 21, and the parent gear is used as an output gear 27 c of the rotor 27. And the child gear is engaged with the tooth portion 25b of the aperture ring 25.

  Next, the operation of this embodiment will be described with reference to FIGS. 9 and 11 to 15. FIG. 9 shows a state in which the camera is turned on and the shutter blades 3 and 4 and the seven diaphragm blades 26 are in the initial positions and can be photographed. The reason why the state is surely obtained will be explained. First, in the case of the shutter blades 3 and 4, as already described, even when the coil 12 is in a non-energized state, the magnetic force of the rotor 9 is between the magnetic rods (iron pins) (not shown). Therefore, the initial position can be reliably maintained by bringing the output pin 9a of the rotor 9 into contact with one end face of the long hole 21d of the main base plate 21 regardless of whether the power of the camera is on or off. Is possible. In addition, even if a strong impact is applied and the motor rotates slightly from the initial position, it immediately returns to the initial position due to the attractive force acting between the rotor 9 and the magnetic rod (iron pin). Be restored.

  On the other hand, in the case of the diaphragm blade 26, when a strong impact is applied to the camera, the diaphragm ring 25 may stop at a slightly rotated position, and the diaphragm blade 26 may not return to the initial position. In addition, even when the battery runs out during the previous shooting, it may not be possible to return to the initial position, and may remain stopped at a position shifted together with the aperture ring 25. Therefore, in the past, assuming such a case, when the power was turned on, the diaphragm device was first operated to automatically return the diaphragm blades to the initial position. This is also possible in some cases. That is, in the case of the present embodiment, when the power of the camera is turned on, the step motor is started, the output gear 27c of the rotor 27 rotates the aperture ring 25 via the reduction gear 32, and the aperture ring 25 When the photosensor 24 emits an L level signal, the rotor 27 is stopped and the initial position of the diaphragm blade 26 as shown in FIG. 9 is obtained. Accordingly, in FIG. 9, the light shielding portion 25 c of the aperture ring 25 blocks the optical path of the photosensor 24.

  In this way, after the state of FIG. 9 is obtained, when the release button is pressed during shooting, the exposure time and aperture value are determined based on the measurement result of the photometry circuit. However, in the case of the present embodiment, the aperture device is always operated first regardless of the determined aperture value. That is, first, when a pulse signal is given to the coils 30 and 31, the rotor 27 is rotated in the clockwise direction, and the rotation is transmitted from the output gear 27c via the reduction gear 32, so that the aperture ring 25 is rotated. It can be rotated clockwise. However, in the rotation of the aperture ring 25 in this initial stage, the cam groove 25a is partially formed in an arc shape centered on the optical axis, so that the engagement pin 26b of the aperture blade 26 can be pushed. Absent. Therefore, the seven diaphragm blades 26 remain stopped at the initial position. Then, if it is determined by the above measurement result that the image is taken with the maximum aperture, the rotor 27 is stopped before the cam groove 26a starts to push the engagement pin 26b. The state at that time is shown in FIG. 11. In this state, the photosensor 24 is in the H level signal generation state.

  When shooting with the maximum aperture opening, the shutter device is operated as described later in the state shown in FIG. 11, but in other cases, the rotor 27 is not stopped in the state shown in FIG. The clockwise rotation can be continued. Therefore, the cam groove 25a of the aperture ring 25 starts to push the engagement pin 26b of the aperture blade 26, and simultaneously rotates the 7 aperture blades 26 counterclockwise to enter the opening 23a. When the diaphragm blades 26 reach a predetermined diaphragm opening control position, the pulse signals for the coils 30 and 31 are cut off, and the rotation of the rotor 27 is stopped. FIG. 12 shows a state in which the seven diaphragm blades 26 are stopped at a predetermined diaphragm opening control position.

  In this manner, when the operation of the aperture device stops, immediately after that, the charge accumulated in the solid-state imaging device is released by a signal from the exposure control circuit. For this reason, exposure for photographing is started, and charges are accumulated in the solid-state imaging device. Then, when a predetermined time determined by the measurement result has elapsed, the coil 12 starts to be energized in the positive direction, and the rotor 9 is rotated clockwise. Therefore, the shutter blades 3 and 4 are simultaneously rotated in opposite directions from the initial position. However, as shown in FIG. 13, immediately before the opening 23a starts to close, the tip of the shutter blade 4 is moved to the photosensor 24. Block the light path. Therefore, the photosensor 24 emits an L level signal from that moment.

  Therefore, also in the case of this embodiment, as in the case of Embodiments 1 and 2, the time from the start of energization to the coil 12 until the photosensor 24 generates an L level signal is measured at the time of manufacture. When the time is different from the design reference time, by adjusting the time from the start of charge re-accumulation to the solid-state imaging device performed after the discharge of charge as described above to the start of energization to the coil 12, A design reference time can be obtained. In addition, depending on the specifications of the camera, it is possible to warn that proper exposure cannot be obtained when the design reference time is deviated for some reason after marketing.

  After the shutter blade 4 generates an L level signal in the photosensor 24, the shutter blades 3 and 4 close the opening 23a. When the opening 23a is closed, an H level signal is generated again from the photosensor 24, but the signal is ignored. Thereafter, when the output pin 9a of the rotor 9 comes into contact with the end face of the long hole 21d of the main base plate 21, the rotation of the shutter blades 3 and 4 together with the rotor 9 is stopped. This state is the state shown in FIG. However, due to individual differences, some of the shutter pins 3 and 4 bounce to the state shown in FIG. 15 due to the reaction when the output pin 9a comes into contact with the end face of the long hole 21d. However, in this embodiment, such a phenomenon occurs in the second time that occurs after the shutter blades 3 and 4 start operating until the coil 12 (described later) starts energizing in the reverse direction. Therefore, it is possible to take measures such as immediately replacing the shutter blades 3 and 4.

In this manner, when the shutter blades 3 and 4 are closed, the imaging information is transferred to the storage device in the state shown in FIG. When the transfer ends, the coil 12 is energized in the opposite direction to the above, and the rotor 9 is rotated counterclockwise. As a result, the shutter blades 3 and 4 perform an opening operation, generate an L level signal from the photosensor 24, and generate an H level signal after the opening 23a is fully opened, but these signals are ignored. Is done. Thereafter, when the output pin 9a of the rotor 9 comes into contact with the end face of the long hole 21d of the main base plate 21, the shutter blades 3 and 4 are also stopped and the energization to the coil 12 is cut off.

  On the other hand, since the reverse pulse signal is also applied to the coils 30 and 31 of the step motor, the rotor 27 is rotated counterclockwise, and the aperture ring 25 is rotated counterclockwise. For this reason, the engagement pin 26b is pushed by the cam groove 25a, and the seven diaphragm blades 26 are simultaneously rotated clockwise to retreat from the opening 23a. Thereafter, when the opening 23a is fully opened behind the shutter blades 3 and 4, immediately after that, the rotation of the aperture blade 26 stops due to the shape of the cam groove 25a, but the aperture ring 25 still rotates. to continue. Then, after the shutter blades 3 and 4 return to the initial positions, when the light shielding portion 25c blocks the optical path of the photosensor 24, the pulse signal to the coils 30 and 31 is cut off by the L level signal at that time. Return to state 9. Therefore, the present embodiment has an advantage that the aperture blade can be positioned at the initial position in addition to the case of the second embodiment even though the number of photosensors is one.

  In the description of the shutter device in each of the above embodiments, at the time of manufacture, the photosensors 5, 16, and 24 are initially set to L level signals after energization for the closing operation is started for the coil 12. Is measured, and when the time is different from the design reference time, the time from the start of charge re-accumulation to the solid-state imaging device after the release of the released charge to the start of energization of the coil 12 is measured. It has been explained that the design reference time can be obtained by adjusting the time. However, the present invention is not limited to such a case. This is because, depending on the specifications of the shutter device, the timing for starting charge re-accumulation for the solid-state imaging device may be later than the timing for starting energization for the coil 12. In such a case, the charge accumulation to the solid-state imaging device is started before the shutter blade starts to close the exposure opening, and after the shutter blade starts to close the exposure opening. In some cases, charge accumulation in the solid-state image sensor is started (so-called triangular exposure characteristics are obtained). Therefore, the adjustment in accordance with the design reference time is a relative timing adjustment between the charge re-accumulation start timing for the solid-state imaging device and the energization start timing for the coil 12.

  Therefore, among the above, an adjustment method in the case where charge accumulation for the solid-state imaging device is started after the shutter blades have started to close the exposure opening will be described. The control of the maximum exposure amount in that case is a case where charge re-accumulation for the solid-state imaging device is started at time C in FIG. When reducing the exposure amount so that an appropriate exposure amount can be obtained at the time of shooting, the timing for starting the re-accumulation of charges on the solid-state imaging device is delayed or the timing for starting energization of the coil 12 is increased. become. Therefore, in the case of the shutter device having such a configuration, the shutter device is operated under the photographing conditions that achieve the appropriate exposure with the maximum exposure amount, and the photosensors 5, 16, and 24 first issue the L level signal. It is only necessary to determine a timing for starting energization of the coil 12 so that the re-accumulation of the charge on the solid-state imaging device can be started at the time (time C in FIG. 5). In any case, in the case of a shutter device that performs such exposure control, if the time from the initial position of the shutter blade to the start of closing the exposure opening deviates from the design reference time, the exposure amount due to the deviation time This kind of adjustment is indispensable because the difference in the above will affect the normal exposure amount as a large error (ratio).

  Further, the shutter device of each of the above embodiments includes two shutter blades rotating in opposite directions, but the present invention may be a shutter device including only one of the blades, The actuator for driving the shutter is not limited to the moving magnet type motor, and may be another electromagnetic actuator such as a step motor or a plunger. In each of the above embodiments, the motor directly drives the shutter blade. However, the present invention includes one in which the electromagnetic actuator drives the shutter blade via another member.

  In the diaphragm device of the third embodiment, the step motor drives a plurality of diaphragm blades via the diaphragm ring. In the present invention, the diaphragm device unitized with the shutter device is like that. However, the step motor may be replaced with another electromagnetic actuator, or one or two diaphragm blades may be directly driven without using the diaphragm ring. Needless to say, the single blade is a diaphragm blade having a diaphragm aperture having a smaller diameter than the exposure aperture. Further, in the third embodiment, the shutter chamber and the diaphragm chamber are configured by the intermediate plate. However, as described in Patent Document 1, the intermediate plate is not necessarily required.

It is the top view of Example 1 which showed the state which has a shutter blade | wing in an initial position. 1 is a cross-sectional view of a main part of Example 1. It is the top view of Example 1 which showed the state which the shutter blade | wing closed the exposure opening and contact | abutted to the stopper. It is the top view which showed the state which the shutter blade | bound bound from the state of FIG. 6 is a timing chart for explaining timing when shutter blades start closing operation. It is the top view of Example 2 which showed the state which has a shutter blade | wing in an initial position. It is the top view of Example 2 which showed the state which closed the exposure opening and the shutter blade | wing contact | abutted to the stopper. It is the top view which showed the state which the shutter blade | bound bound from the state of FIG. FIG. 10 is a plan view of Example 3 showing a state in which the shutter blades and the diaphragm blades are in the initial positions. FIG. 10 is an essential part cross-sectional view of FIG. FIG. 10 is a plan view showing a state in which the aperture ring has started rotating from the state of FIG. 9 but the aperture blades are still in the initial position. FIG. 12 is a plan view showing a state in which the aperture ring is further rotated from the state of FIG. 11 and the aperture blades are stopped at a predetermined aperture opening control position. FIG. 13 is a plan view showing a state immediately before the shutter blade starts to close and starts to close the exposure opening from the state of FIG. 12. FIG. 14 is a plan view showing a state in which the shutter blade closes the exposure opening from the state of FIG. 13 and contacts the stopper. It is the top view which showed the state which the shutter blade | bound bound from the state of FIG.

Explanation of symbols

1,21 Main ground plate 1a, 2a, 21a, 22a, 23a Opening 1b, 1c, 21b, 21c, 21e, 21f Shaft 1d, 1e, 1f, 1g Stopper 1h, 11a, 21d, 23b Long hole 2,22 Auxiliary ground plate 2b, 22b Long groove 3, 4 Shutter blade 5, 6, 16, 24 Photo sensor 7, 8 Reflective sheet 9 Rotor 9a Output pin 10 First stator frame 11 Second stator frame 12, 30, 31 Coils 13, 28 , 29 Yoke 14, 15 Screw 23 Intermediate plate 25 Diaphragm ring 25a Cam groove 25b Teeth part 25c Light-shielding part 26 Diaphragm blade 26a Shaft pin 26b Engaging pin 27 Rotor 27a Shaft part 27b Permanent magnet 27b Output gear 32 Reduction gear

Claims (4)

Each has an opening for a photographing optical path, restricts the exposure opening at least one of the openings, and is disposed in the blade chamber, and constitutes a blade chamber therebetween. And at least one shutter blade that opens and closes the exposure opening, and a shutter drive electromagnetic actuator that is attached to one of the base plates and causes the shutter blade to open and close the exposure opening. A first photosensor for detecting a first position of the shutter blade just before starting to close the exposure opening after starting the operation from an initial position, and a first signal at the stage where the shutter blade closes the exposure opening second signal said first signal and the second signal generated is ignored at the stage of opening the part of the temporarily said exposure aperture to bounce after closing the exposure opening to generate the said sheet Digital camera shutter, characterized in that it comprises a second photo sensor that is jitter detection signal of the second position of the blade, the.   The shutter for a digital camera according to claim 1, wherein the first photosensor and the second photosensor are one photosensor.   At least one diaphragm blade that is disposed in the blade chamber and restricts a diaphragm aperture that is smaller than the exposure opening, and an initial position that is attached to one of the base plates and retracts the diaphragm blade from the exposure opening An aperture-driving electromagnetic actuator for advancing and retreating from the exposure aperture to the exposure aperture, wherein the one photosensor includes at least one of the first position and the second position of the shutter blade, and an initial position of the diaphragm blade. The shutter for a digital camera according to claim 2, wherein the position is detected. The opening disposed in the two ground planes and disposed between the two ground planes, forming a shutter chamber between one ground plane and a diaphragm chamber between the other ground planes An intermediate plate having an opening for restricting the exposure opening by at least one of the shutter blades, the shutter blades being disposed in the shutter chamber, An aperture ring that is reciprocally rotated around the exposure aperture by an electromagnetic actuator, and a plurality of aperture blades that are simultaneously reciprocated in the same direction by rotation of the aperture ring are arranged, and the one photosensor is 4. The shutter for a digital camera according to claim 3, wherein the initial position of the aperture blade is indirectly detected by detecting the position of the aperture ring.