JP4533485B2 - Shutter for digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shutter that is optimal for a digital camera that electronically shoots with an electronic image pickup device such as a CCD, and a position where the electronic image pickup device such as a CCD is opened for shooting, and the accumulated charge. A plurality of shutter blades that reciprocate between two positions: a position where an electronic image sensor such as a CCD is closed in order to prevent a malfunction from occurring due to incident light from the outside when the image is transferred to the recording unit The shutter blades are moved from a predetermined position due to vibrations or shocks to the camera during the movement between the photographing positions. However, for a digital camera configured to constantly monitor with a sensor and always return the shutter blade to a predetermined position so as to immediately enter a shooting state without missing a photo opportunity On Yatta.
[0002]
[Prior art]
Conventionally, in a digital camera equipped with an electronic image pickup device such as a CCD, the exposure opening is opened and closed by a reciprocating operation of an actuator engaged with a plurality of shutter blades. Although the exposure opening was closed and controlled to prevent the occurrence of malfunction due to the incidence of external light when transferring the charged charge to the recording unit, it was used for such a shutter for a digital camera. Many of the actuators that rotate are reciprocating by rotating when energized, and do not have a special locking / release mechanism or control mechanism because of the low cost requirements of the shutter device. Was almost.
[0003]
[Problems to be solved by the invention]
As described above, in the shutter for the digital camera, since the image is taken electronically at the time of shooting, it is only necessary to open the opening for exposure, and the charge accumulated in the electronic image sensor such as a CCD after shooting is not shown. In order to prevent malfunction caused by external light, it was necessary to shield the information from the camera body side.
That is, only one-way operation from opening to closing is required for the shutter operation during photographing.
However, in the above-described conventional examples, most of the shutters are for digital cameras using actuators that simply rotate and reciprocate, and do not have a special locking / release mechanism or control mechanism. Therefore, if you carry the digital camera while hanging it with a strap or the like between shots, the shutter blades move relatively easily from the open position, which is the predetermined position during shooting, due to vibration and shock. It was.
For this reason, it is necessary to always control the actuator to be in the open position, which is a predetermined position at the time of photographing, by energizing the actuator engaged with the plurality of shutter blades at the time of photographing. Due to the time delay that occurs as a preparation time for the image, a good photo opportunity is often missed, and there is a problem that no consideration is given to the responsiveness of shooting.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the shutter for a digital camera of the present invention is disposed in front of the image sensor, and has two positions: an open position where the exposure opening is fully opened and a closed position where the exposure opening is fully closed. A plurality of shutter blades that reciprocate between them, a sensor that detects whether the shutter blades are on the open position side or the closed position side, and the shutter blades that engage with the shutter blades to reciprocate between the two positions. An actuator for driving, and a control unit that controls energization of the actuator, wherein the control unit is configured so that the shutter blades are held in an open position and the sensor is in the shooting preparation state before shooting operation is possible. When the shutter blade open position is not detected When the shutter blade is opened and energized to open the shutter blade, the release operation is performed Shooting by the image sensor is started while the shutter blade is held in the open position, and after a predetermined time has passed, the actuator is closed and energized to cause the shutter blade to perform a closing operation to complete the shooting. To.
[0005]
In the shutter for a digital camera of the present invention , the actuator is
A moving magnet type actuator to have a magnetic material for the non-energized holding the two positions of the closed position and the open position.
[0006]
In the shutter for a digital camera of the present invention, the sensor is provided on the ground plane.
When the shutter blades are in the open position, the optical reflection type photocoupler is disposed and a reflective sheet affixed to the shutter upper lid for forming a space for arranging the shutter blades between the photoreflective photocoupler and the base plate. the output of the photocoupler said shutter blade covering the emission light of the photocoupler is set to a low level, by the shutter blade is retracted when the shutter blade is in the closed position, the outgoing light / incident of the photocoupler the reflection sheet is functioning facing the light unit, so that is configured to the output high.

[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention using two preferred shutter blades will be described with reference to FIGS.
1 is a plan view showing a shutter blade closed state, FIG. 2 is a plan view showing a shutter blade open state, FIG. 3 is a plan view of the actuator, FIG. 4 is a cross-sectional view taken along line AA of the actuator, and FIG. FIG. 6 is a cross-sectional view of the photocoupler in the shutter blade closed state, FIG. 6 is a cross-sectional view of the photocoupler in the shutter blade open state, FIG. 7 is an operation timing chart, and FIG.
Throughout the drawings, the same reference numerals indicate the same symmetry.
[0008]
First, in FIG. 1, which is a plan view showing a shutter blade closed state, a circular exposure opening 2 is opened at the center of the shutter base plate 1, and the exposure opening 2 is composed of two shutter blades. The shutter blade 3 and the shutter blade 3a are closed and are in a fully closed state.
A moving magnet type actuator 5 is attached to the shutter base plate 1, and an operating pin 6 formed integrally with a rotor magnet 9 which is a component of the actuator 5 extends to perforate two shutter blades. The two shutter blades 3, 3 a are also interlocked with the rotor magnet 9 and the operating pin 6 that rotate by a predetermined angle by applying a DC voltage to the actuator 5. It moves by a predetermined angle and shifts from the shutter blade closed state of FIG. 1 to the state of FIG. 2 which is a plan view showing the shutter blade open state.
[0009]
Subsequently, by applying a reverse polarity DC voltage, the two shutter blades move by a predetermined angle from the shutter blade open state of FIG. 2 to the shutter blade closed state of FIG. Will return.
In this way, two sheets that reciprocate at a predetermined angle between the two states of the shutter closed state in which the exposure opening is fully closed and the shutter open state in which the exposure opening is fully opened. A shutter for a digital camera using shutter blades is configured.
[0010]
Next, the configuration and operation of the actuator 5 will be described with reference to FIG. 3, which is a plan view of the actuator, and FIG. 4, which is a sectional view taken along the line AA of the actuator.
As shown in FIG. 3, the rotor magnet 9 installed at the center of the moving magnet type actuator 5 has its outer periphery equally divided into two poles, N pole and S pole, and is shown in FIG. Are formed integrally with the extended operating pin 6 and the central axis of the rotor magnet 9.
The coil upper frame 10 shown in FIG. 4 is a molded product made of an electrically insulating material such as plastic resin, and functions as an outer cylinder of the actuator 5, a function of the coil frame, a function of a bearing of the central shaft of the rotor magnet 9, and a diaphragm. cut iron pin 1 2,12 and stop outright iron pin 1 2 a, and has a function of 12a positioning fixing hole of the fixing function of the yoke 7.
The coil lower frame 11 shown in FIG. 4 is also a molded product made of an electrically insulating material such as plastic resin, and functions of the coil frame, the bearing of the central axis of the rotor magnet 9, and the sealing lid of the actuator 5. It has the function of
[0011]
That is, one end of the central axis of the rotor magnet 9 corresponding to the operating pin 6 side in FIG. 4 is inserted into the bearing hole 13 of the coil lower frame 11, and the other end on the opposite side is the coil upper frame 10. After being inserted into the bearing hole 13, the coil lower frame 11 and the coil upper frame 10 are fixed together.
The fixing method may be based on adhesion or a method such as press fitting, but the bearing holes 13 of the coil upper frame 10 and the coil lower frame 11 are provided so that the rotor magnet 9 can freely rotate. Must be fixed after being adjusted concentrically.
Further, from above the integrated coil upper frame 10 and coil lower frame 11, an insulating film copper wire such as a polyurethane film is wound around a rectangular groove for winding formed on the coil and the lower frame. The coil 8 is formed by fixing the winding start and the winding end to the two terminals by soldering.
After that, after a pair of drawn iron pins 12 and 12 and another pair of drawn iron pins 12a and 12a are inserted and fixed in the long holes provided in four places in the coil upper frame 10 shown in FIG. A cylindrical yoke 7 is inserted and fixed from the outside to the position shown in FIGS. 3 and 4 so as to wrap the lower frame on the coil, and the actuator 5 is completed.
[0012]
The action of the pair of squeezed iron pins 12 and 12 and the other pair of squeezed iron pins 12a and 12a is for positioning the rotor magnet 9 which is magnetized equally to the two poles of the N pole and the S pole. Since the strongest locking force is obtained at the position shown in FIG. 3 where the position of the pin and the position of the center of the N pole or the S pole coincide with each other, four non-energized holdings can be obtained in one rotation. It is supposed to be.
In the present embodiment, the positional relationship between each pair of aperture iron pins 12 and 12a and the rotor magnet 9 is set so as to match the shutter blade open position and the shutter blade close position so that the strongest locking force can be obtained. Therefore, even if the digital camera is carried while being suspended by a strap or the like during shooting, the shutter blades are unlikely to move from a predetermined position due to vibrations or shocks. Due to the interaction between the cutting iron pins 12 and 12a and the rotor magnet 9, it is surely drawn out to either the shutter blade open position or the shutter blade closed position where the strongest locking force is generated, and is kept unenergized. It will be.
[0013]
Next, regarding the function and action of the photocoupler as a sensor, FIG. 1 is a plan view showing the shutter blade closed state, FIG. 2 is a plan view showing the shutter blade open state, and a cross-sectional view of the photocoupler in the shutter blade closed state 5 and FIG. 6 which is a cross-sectional view of the photocoupler in the shutter blade open state will be described.
First, the optical reflective photocoupler 4 is positioned so that the shutter blade 3 covers the outgoing light portion of the photocoupler 4 in the shutter open state in which the exposure opening is fully opened as shown in FIG. Since it is installed on the shutter base plate 1, the light emitted from the photocoupler 4 is blocked by the shutter blade 3 as shown in FIG. 6, so that the output of the photocoupler is low, contrary to that shown in FIG. When the shutter is closed, as shown in FIG. 5, the photocoupler 4 functions by the action of reflection of the reflection sheet 15 affixed to the surface of the shutter upper cover 14 facing the outgoing light / incident light portion of the photocoupler 4, and its output is It is configured to be a high level.
[0014]
Functions relating to the opening / closing of the shutter blades and the CCD operation as the electronic image sensor will be described with reference to FIG.
The CCD is located on the camera body side (not shown) at a position where a subject forms an image.
First, the consistency between the output signal of the photocoupler 4 constantly monitored with the camera power ON and the information of the information processing unit mounted on the digital camera body is checked.
If the camera is set in the shooting ready state, the alignment (YES) indicates that the shutter blades 3, 3a, which are predetermined positions at the time of shooting, indicate the open position, and the camera is ready for shooting. At the same time, photographing and exposure are started and accumulation in the CCD is performed.
[0015]
However, when the shutter blades 3 and 3a are moved from a predetermined position at the time of shooting due to vibration or shock, a judgment of mismatch is made and the moving magnet type actuator 5 is controlled to be energized. Therefore, the shutter blades 3 and 3a return to the open position, which is a predetermined position at the time of shooting.
In the present embodiment, a rectangular control voltage having an energization time of 15 msec is applied to the actuator 5 by the control unit.
In this case, the consistency check is repeated again.
In this way, the digital camera always maintains an optimal shooting preparation state, and immediately starts shooting as soon as the release switch is turned on, and CCD exposure and charge accumulation are performed. Therefore, it is possible to provide a shutter for a digital camera that is well-considered.
Similarly, when the shutter blades 3 and 3a that perform accumulation and charge transfer in the CCD are set at a closed position that is a predetermined position during standby, the shutter blades 3 and 3a are always in the standby state. It is maintained at the predetermined position.
[0016]
According to FIG. 7 which is an operation timing chart, in the shutter fully opened state, which is a predetermined position at the time of photographing, photographing is started immediately upon turning on the release switch, and exposure of the CCD and charge accumulation are performed. The control voltage applied to the actuator 5 that drives the 3 and 3a in the closing direction is configured to rise slightly later than that.
Here, the closing operation of the shutter blades 3 and 3a starts further later than the rise of the control voltage because of the electrical time constant of the actuator 5 and the mechanical time constant of the shutter blade.
[0017]
The hatched portion shown in FIG. 7 is the total exposure amount of the CCD, and the time until the approximate middle point of the shutter blade closing time indicates the effective exposure time.
The open position of the shutter blades fully open and the closed position of the shutter blades fully closed are both set to positions having an operation amount slightly larger than the opening diameter position and the pinhole position. The timing chart shown in FIG. 7 shows that the position where the shutter blades 3 and 3a are stopped in an incompletely opened state and incompletely closed is not generated. It is shown.
Here, it is clear that the two positions are set as the non-energized holding positions of the shutter blades 3 and 3a.
Thus, after shooting, the shutter blades 3 and 3a are closed to prevent a malfunction from being caused by the incidence of light from the outside when the charge accumulated in the CCD is transferred to the recording unit.
【The invention's effect】
As mentioned above, also be mobile while hanging digital camera strap or the like, it is also rarely shutter blade 3,3a by vibration or impact because of the self-holding mechanism of the actuator 5 will move from the predetermined position, moving if that Do with what shutter blade 3,3a is engaged always either unpowered holding position of the actuator 5 even. In the photographing preparation state, energizing and information output of the photo coupler 4 in the normal time monitoring state, the information processing unit to determine the function of the digital camera, but the actuator 5 by the control unit only when the inconsistency control to, since it is configured so as to return the shutter blade 3,3a to the open position, it is maintained at all times optimum shooting preparation state, provide a well-friendly digital camera shutter for readiness to filming can Ru.
[Brief description of the drawings]
FIG. 1 is a plan view showing a shutter blade in a closed state. FIG. 2 is a plan view showing a shutter blade in an opened state. FIG. 3 is a plan view of an actuator. Cross-sectional view of the photocoupler in the state [FIG. 6] Cross-sectional view of the photocoupler in the shutter blade open state [FIG. 7] Operation timing chart diagram [FIG. 8] Operation flowchart diagram [Explanation of symbols]
1 shutter base plate 2 opening for exposure 3 shutter blade 1
3a Shutter blade 2
4 Photocoupler 5 Actuator 6 Actuation pin 7 Yoke 8 Coil 9 Rotor magnet 10 Coil upper frame 11 Coil lower frame 12 Drawing iron pin 1
12a Drawing iron pin 2
13 Bearing hole 14 Shutter top cover 15 Reflective sheet

Claims (3)

A plurality of shutter blades disposed in front of the image sensor and reciprocating between two positions, an open position where the exposure opening is fully opened and a closed position where it is fully closed, and the shutter blade is in the open position A sensor for detecting whether it is on the side or the closed position side, an actuator that engages with the shutter blades and reciprocates between the two positions, and a controller that controls energization of the actuator,
The control unit causes the shutter blade to perform an opening operation when the sensor does not detect the open position of the shutter blade in a photographing ready state before the release operation in which the shutter blade should be held in the open position. Therefore, when the shutter is opened and energized, and the shutter blade is held in the open position when the release operation is performed, photographing with the imaging element is started, and after a predetermined time has elapsed, the shutter blade is used to complete the photographing. To close and energize the actuator to perform the closing operation.
The shutter for digital cameras characterized by the above-mentioned. 2. The shutter for a digital camera according to claim 1, wherein the actuator is a moving magnet type actuator, and has a magnetic material for holding a non-energized state at two positions of the open position and the closed position. The sensor includes an optical reflective photocoupler provided on a ground plate, and a reflective sheet affixed to a shutter upper cover for forming a space for arranging the shutter blade between the ground plate and the shutter blade. When the shutter blade is in the open position, the shutter blade covers the outgoing light portion of the photocoupler, the output of the photocoupler is set to a low level, and when the shutter blade is in the closed position, the shutter blade is retracted, thereby 3. The shutter for a digital camera according to claim 1, wherein the reflection sheet facing the outgoing light / incident light part of the coupler functions to make its output high level.

Images