JP4034412B2 - Electronic imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic imaging apparatus that includes independent diaphragm blades and a shutter in an electronic imaging apparatus that records subject light that has passed through a lens barrel by converting it into an electrical signal using an imaging device.
[0002]
[Prior art]
In a conventional electronic imaging apparatus, the shutter and the diaphragm blades are kept in an operating state by continuously energizing a driving electromagnetic solenoid during operation. In that case, if energization is continued, the power consumption naturally increases. Further, if other operations are performed simultaneously during that period, the voltage peaks overlap, and particularly in the case of a portable power supply, there is a possibility that the system may stop due to a voltage drop.
[0003]
Therefore, the applicant of the present application previously disclosed in Japanese Patent Application No. 9-244377, a diaphragm that mechanically adjusts the amount of light beam applied to the image sensor, and a shutter that mechanically adjusts the time applied to the image sensor. Have proposed an electronic image pickup apparatus having an aperture shutter unit, each of which is composed of independent blades and each drive source is added thereto. In this imaging apparatus, by adjusting the control timing of the aperture drive source and the shutter drive source, the simultaneous energization state is eliminated, the burden on the battery is reduced, and the battery life is extended.
[0004]
[Problems to be solved by the invention]
The electronic imaging device disclosed in Japanese Patent Application No. 9-244377 is effective in increasing the battery life since the simultaneous driving state of each driving source is eliminated. However, it is insufficient in terms of downsizing and power saving of the apparatus main body, and further improvement is desired. For example, it is desired to develop a device capable of sufficient power saving by further considering the drive time and timing of each of the image sensor, the diaphragm, and the shutter.
[0005]
The present invention has been made to solve the above-described problems, and an object thereof is to provide an electronic image pickup apparatus capable of sufficiently saving power for an aperture during operation of the image sensor and / or a shutter drive source. To do.
[0006]
A first electronic imaging device of the present invention is an electronic imaging device that records subject light that has passed through a lens barrel by converting it into an electrical signal with an imaging device, and is disposed within the lens barrel and closes an opening. A shutter blade that is driven to a position where the aperture is opened and a position that opens the aperture; a diaphragm blade that is disposed in the lens barrel and moves forward and backward in the optical path to narrow the light beam; and for driving the shutter blade A voltage is applied to the diaphragm drive source prior to charge accumulation by the imaging device, a shutter drive source, a diaphragm drive source for driving the diaphragm blade, diaphragm blade holding means for holding the diaphragm blade in a predetermined position, and The diaphragm blade is driven to move to a position for converging the light flux, and voltage application to the diaphragm drive source is stopped prior to charge accumulation by the image sensor, and the diaphragm blade holding means is used to stop the diaphragm blade. And after the charge accumulation by the image sensor is completed, a first voltage is applied to the shutter driving source to drive the shutter blades to move to a position to close the opening. the low voltage is applied to the shutter driving source the shutter blades After holding the position for closing the opening, and a control means for controlling to start the signal charge transfer of the image pickup device, by comprising the Features.
[0007]
According to a second electronic imaging device of the present invention, in the first electronic imaging device, the shutter driving source is movable so that it can take a solenoid, a state protruding from the solenoid, and a state attracted by the solenoid. The shutter blade has an iron core and a return spring that urges the movable iron core in the protruding direction, and the first iron voltage is applied to attract the movable iron core against the urging force of the return spring. Is moved to a position to close the opening, and the second voltage is applied to hold the movable iron core in a suction state, thereby holding the shutter blade in a position to close the opening and applying a voltage. Is stopped, and the shutter blade is driven to move to a position where the opening is opened by the biasing force of the return spring.
[0008]
According to a third electronic imaging device of the present invention, in the first electronic imaging device, the diaphragm driving source is a bidirectional electromagnetic actuator capable of selecting an operation direction according to the polarity of energization, The blade holding means is means for holding the diaphragm blade by a stationary holding torque generated between the rotor and the yoke when the yoke coil in the bidirectional electromagnetic actuator is in an unexcited state. The diaphragm blade is moved to a predetermined position by energization of the aperture, the diaphragm blade is held at a predetermined position by the diaphragm blade holding means, and the energization to the bidirectional electromagnetic actuator is terminated. Performs signal charge transfer operation and moves the diaphragm blades to the open position after the exposure and signal charge transfer operations of the image sensor Allowed, characterized in that it is controlled by the control means so as to retain the open position of the aperture blade by the diaphragm blade holding means.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of an electronic image pickup apparatus according to an embodiment of the present invention. The electronic imaging device of the present embodiment is mainly composed of a photographing lens system 1 built in a lens barrel 20, a diaphragm device 2 that is also built in the lens barrel 20, and narrows down the luminous flux of subject light, and a subject. A mechanical shutter device 3 that shields a light beam, a CCD (imager) 4 that converts an object image captured by the photographing lens system 1 into an electrical signal, and an output signal from the CCD 4 to capture an image signal such as a sample hold. Recording / reading is controlled by an imaging circuit 5 that performs processing, an A / D conversion circuit 6 that performs A / D conversion on a video signal output from the imaging circuit 5, and a system controller 12, and output from the A / D conversion circuit 6. A digital video signal stored in the memory 7, a D / A conversion circuit 8 for reading out the digital video signal stored in the memory 7 and performing D / A conversion, and D An LCD monitor 9 that monitors the video signal output from the A conversion circuit 8 and a compression that reads and compresses the digital video signal stored in the memory 7 and reads and decompresses the digital video signal recorded in the memory card 11 A decompression circuit 10, a removable memory card 11 on which a digital video signal is recorded, a system controller 12 which is a control means for controlling all the control elements of the apparatus, and an aperture drive source for driving the aperture apparatus 2. A certain diaphragm actuator 35, a shutter plunger 32 as a shutter drive source for driving the mechanical shutter device 3, a diaphragm control circuit 15 for controlling on / off of the diaphragm actuator 35, and a shutter control circuit 14 for controlling on / off of the shutter plunger 32 It consists of
[0011]
FIG. 2 is an exploded perspective view of a diaphragm / shutter unit in which the diaphragm device 2, the mechanical shutter device 3 and its drive source are incorporated. FIG. 3 is a front view of the diaphragm / shutter unit. The abbreviation is shown.
[0012]
The diaphragm / shutter portion constitutes a support plate 31 having a photographic lens opening 31a, a shutter plunger 32 and a diaphragm actuator 35 attached to the support plate 31, and a mechanical shutter device, and is rotatably supported by the support plate 31. Shutter lever 39 and shutter blades 37, 38, a shutter blade portion having a photographing lens aperture 40a and a separator 40 for separating the diaphragm portion, and a diaphragm blade having a sliding surface for the photographing lens aperture 42a and the diaphragm blade 41. It comprises a base 42 and a diaphragm blade 41 that constitutes a diaphragm device and is rotatably supported by the diaphragm blade base 42.
[0013]
The support plate 31 includes a support pin 31c that rotatably supports the shutter lever 39, support pins 31d and 31e that rotatably support the shutter blades 37 and 38 through shaft holes 37a and 38a, and a diaphragm. An opening 31b through which the drive pin 36b of the drive lever 36 fixed to the output shaft 35c of the actuator 35 is inserted is provided. The size of the photographic lens opening 31a provided in the support plate 31 is a diaphragm F4 as a lens diaphragm value.
[0014]
The shutter plunger 32 includes a solenoid 32a, a movable iron core 33 that can be protruded and sucked, and a return spring 34 that urges the movable iron core 33 in the protruding direction. The movable iron core 33 is provided with a groove 33c into which the drive protrusion 39c of the shutter lever 39 is fitted. When the first voltage V1 is applied to the solenoid 32a, the movable iron core 33 is attracted against the return spring 34. Thereafter, even if the voltage applied to the solenoid is lowered to a second voltage V2 lower than the first voltage V1, the suction state of the movable iron core 33 is maintained.
[0015]
The shutter lever 39 has a drive protrusion 39c and a drive pin 39b, and the drive pin 39b is fitted in the long holes 37b and 38b of the shutter blades 37 and 38. In a state where the movable iron core 33 is sucked, the shutter blades 37 and 38 are rotationally driven through the shutter lever 39 to a position where the photographing lens opening 31a is closed. In the state where the movable iron core 33 protrudes, as shown in FIG. 3, the shutter blades 37 and 38 rotate to a position where the photographing lens opening 31a is opened.
[0016]
The diaphragm actuator 35 is a self-holding bidirectional electromagnetic actuator, and FIG. 4 is a schematic cross-sectional view showing an internal structure thereof. The aperture actuator 35 includes a rotor 35a made of a permanent magnet, a yoke 35b having four yoke coils, an output shaft 35c integrated with the rotor 35a, a projection 35d fixed to the output shaft, and a contact with the projection 35d. Possible stoppers 35e and 35f are provided. A drive lever 36 having a drive pin 36b is fixed to the output shaft 35c with a shaft hole 36a.
[0017]
The aperture actuator 35 is rotationally driven to a position P35A or P35B where the protrusion 35d abuts against the stoppers 35e and 35f by application of an A-phase or B-phase pulse voltage to the yoke coil. Thereafter, when the current to the yoke coil is cut off, the yoke 35 is held stationary at the position P35A or P35B with a predetermined self-holding torque by the magnetic attraction force of the rotor 35a.
[0018]
The aperture blade 41 has a predetermined aperture value, for example, an aperture aperture 41c of F8, and is rotatably supported by the support pin 42b of the aperture blade base 42 via the shaft hole 41a. The drive pin 36 b of the drive lever 36 of the diaphragm actuator 35 is fitted in the long hole 41 b of the diaphragm blade 41. Then, as shown in the state diagram of the diaphragm blade operation in FIG. 5, the diaphragm blade 41 is retracted from the rotation position P41A where the diaphragm F8 is in a state of covering the peripheral portion of the photographing lens opening 31a and the photographing lens opening 31a. The diaphragm actuator 35 is rotationally driven between the rotational positions P41B in the state of the diaphragm F4.
[0019]
The diaphragm blade 41 has a projection 42c provided on the diaphragm blade base 42 as a diaphragm blade holding mechanism and a click hole in which the projection 42c can be fitted when the diaphragm blade 41 is in the rotation positions P41A and P41B. 41d and 41e are provided. When the protrusion 42c is fitted into the click holes 41d and 41e, the diaphragm blade 41 is held at the rotational position with a predetermined stationary holding torque. This holding force acts so as to hold the diaphragm blade 41 in cooperation with the self-holding torque at the position P35A or P35B of the diaphragm actuator 35.
[0020]
As described above, when the diaphragm blade 41 is in the rotation positions P41A and P41B, even if an impact force acts on the diaphragm blade 41 in the non-excited state in which the voltage applied to the yoke coil of the diaphragm actuator 35 is cut off. The diaphragm blade 41 is securely held at the rotational position by the stationary holding torque.
[0021]
Here, a modified example of the diaphragm blade holding mechanism using the click ball for holding the diaphragm blade 41 at the rotation positions P41A and P41B will be described. FIG. 6 is an operation diagram of a diaphragm blade holding mechanism to which a toggle spring mechanism is applied as a modification thereof. In this modification, a pin 36 c is provided on the drive lever 36, and a tension spring 45 is suspended between the pin 36 c and the main body of the aperture actuator 35. The drive lever 36 is held at the rotation position P35A or P35B corresponding to the rotation position P41A or P41B of the diaphragm blade 41 by the toggle acting force of the tension spring 45.
According to this modification, it is not necessary to provide a projection for holding the aperture blade, a click hole, etc., the configuration is simplified, and the occupied space is reduced.
[0022]
Next, a photographing operation in the electronic image pickup apparatus of the present embodiment configured as described above, particularly an aperture / shutter opening / closing operation and an image pickup signal capturing operation timing will be described.
[0023]
The luminous flux of the subject that has passed through the photographic lens optical system 1, the diaphragm device 2, and the mechanical shutter device 3 forms an image on the CCD 4, where it is converted into an electrical signal, and then subjected to processing below A / D conversion to produce an image. The signal is output to the LCD monitor 9 as a signal, and an image of the subject is displayed. On the other hand, the video signal is recorded on the memory card 11 after compression processing. The video signal recorded in the memory card 11 is taken in after being decompressed and displayed on the LCD monitor 9.
[0024]
7 and 8 are time charts of the operation of the aperture device and the shutter device when the above-described CCD 4 reads out the electrical imaging signal (electrical signal of the subject image). FIG. 7 shows the case where the progressive type CCD is applied. FIG. 8 shows a case where an interlace type CCD is applied.
[0025]
When the progressive type CCD shown in FIG. 7 is applied, the driving lever 36 is set to the position P35B and the aperture blade 41 is set to the rotation position P41B when the diaphragm blade 41 is opened (F4). Hold on. At this time, since the projection 42c is fitted into the click hole 41d of the diaphragm blade 41, even if an external force or the like due to the operation of the lens barrel 20 is applied, the diaphragm blade 41 is not displaced from the rotation position.
[0026]
On the other hand, the solenoid voltage of the shutter plunger 32 is also OFF, the movable iron core 33 is in the protruding position, and the shutter blades 37 and 38 are held at the lens open positions P37B and P38B. In this state, the photographic lens aperture 31a is in a state of F4 with the aperture open, so that observation with the viewfinder is easy. In the case of this time chart, description will be made assuming that the aperture is set to the aperture F8 at the time of shooting.
[0027]
First, an A-phase voltage pulse is applied to the diaphragm actuator 35 to rotate the diaphragm blade 41 to the diaphragm (F8) position P41A. After the rotation, the voltage applied to the diaphragm actuator 35 is turned off. At this time, the diaphragm blade 41 is in the holding state with the projection 42c inserted into the click hole 41e, so that the diaphragm does not change during the photographing period. Thereafter, exposure of the CCD 4 is started by turning on the CCD shutter.
[0028]
After the elapse of a predetermined exposure time, the CCD shutter is turned off to complete the exposure. Accordingly, the first voltage V1 is applied to the solenoid 32a of the shutter plunger 32 for a predetermined pulse width, and the movable iron core 33 is attracted. Immediately thereafter, the voltage applied to the solenoid 32a is lowered to the second voltage V2 lower than the first voltage, and the suction state of the movable iron core 33 is maintained. By the suction of the movable iron core 33, the shutter blades 37 and 38 are driven from the open positions P37B and P38B to the fully closed position of the photographing lens opening 31a. Note that closing the shutter blades 37 and 38 before the CCD signal charge transfer is performed as a smear countermeasure during the signal charge transfer.
[0029]
After the photographing lens opening 31a is closed, transfer of signal charges for one frame accumulated in the CCD 4 is started. After a predetermined time, when the transfer of the signal charge is completed, the application of the second voltage V2 to the solenoid 32a of the shutter plunger 32 is stopped, the movable iron core 33 is opened, and the shutter blades 37 and 38 are moved to the original positions. Returning to the open positions P37B and P38B, a B-phase voltage pulse is applied to the aperture actuator 35 to return the aperture blade 41 to the initial aperture open (F4) position P41A, and the imaging is completed.
[0030]
Next, the case where the interlace type CCD shown in FIG. 8 is applied will be described. The change in state from the state of the aperture blade and shutter blade at the start of photographing to the start of exposure by the CCD shutter is the case of the progressive type shown in FIG. Is the same. In the case of this interlace type CCD, since signal charge transfer is performed separately for odd and even fields, it is necessary to close the shutter blades 37 and 38 and set the exposure time. The shutter blades 37 and 38 are closed. After the exposure is completed, signal charge transfer is performed in the odd and even fields.
[0031]
That is, during the on-period of the CCD shutter, the first voltage V1 is applied to the solenoid 32a of the shutter plunger 32 for a predetermined pulse width, and the movable iron core 33 is attracted. Immediately thereafter, the voltage applied to the solenoid 32a is held at the second voltage V2 lower than the first voltage, and the suction state of the movable iron core 33 is held. By the suction of the movable iron core 33, the shutter blades 37 and 38 are driven and held in the fully closed position of the photographing lens opening 31a.
[0032]
Thereafter, signal charge transfer is performed in the odd field of the CCD and subsequently in the even field. After completion of the transfer, the application of the second voltage V2 to the solenoid 32a of the shutter plunger 32 is stopped, the movable iron core 33 is opened, and the shutter blades 37 and 38 are moved back to the original open position P37B as in the case of FIG. , P38B, and further, a B-phase voltage pulse is applied to the aperture actuator 35 to return the aperture blade 41 to the initial aperture open (F4) position P41B, thereby completing the photographing.
[0033]
As described above, according to the electronic image pickup apparatus of the present embodiment, during the signal charge transfer of the CCD 4 that consumes a relatively large amount of power, the solenoid applied voltage of the shutter plunger 32 is determined from the first voltage V1 during suction. Since the control is performed so that the second voltage V2 is kept low, the power required for photographing can be saved, and at the same time, the driving power of the solenoid consumed in a state overlapping with the power consumption required for signal charge transfer is reduced, thereby reducing the battery life. Can be extended.
[0034]
Further, since the diaphragm blade 41 is held at the diaphragm opening position and the diaphragm position by the projection 42c of the diaphragm blade base 42, there is no power consumption in the diaphragm actuator 35 during the holding period, and the exposure of the CCD 4 During the charge transfer operation period, the aperture actuator 35 is in an off state, so that power supply destinations do not overlap and power consumption is suppressed.
[0035]
Further, a bi-directional electromagnetic actuator that can be self-held in two rotating states is adopted as the diaphragm actuator 35. Further, in addition to the self-holding function of the actuator itself, the diaphragm by the base protrusion 42c and the blade click holes 41d and 41e. Since the blade mechanism is provided, the position control of the diaphragm blade can be performed reliably and easily, and the size of the diaphragm device can be reduced.
[0036]
【The invention's effect】
As described above, according to the electronic imaging device of the first aspect of the present invention, the signal charge transfer operation of the imaging device is performed in a state where the applied voltage of the shutter driving source is lowered and the shutter blade shielding state is maintained. Therefore, it is possible to save power, and further, since the applied voltages do not overlap, the battery life can be extended.
[0037]
According to the electronic image pickup apparatus of the second aspect of the present invention, in addition to the effect of the electronic image pickup apparatus of the first aspect, the diaphragm blade holding means is provided, thereby providing an aperture drive source during operation of the image sensor. Therefore, it is possible to avoid duplication of applied voltages.
[0038]
According to the electronic imaging device of the third aspect of the present invention, in addition to the effect of the electronic imaging device of the second aspect, the bidirectional electromagnetic actuator is applied as the diaphragm driving source. Directional movement and holding can be easily performed, and furthermore, since the bidirectional electromagnetic actuator is turned off at the time of exposure of the image sensor and at the time of signal charge transfer, power consumption can be suppressed.
[0039]
According to the electronic imaging device of the present invention, in addition to the effect of the electronic imaging device of the third aspect, the self-holding function of the bidirectional electromagnetic actuator for holding the diaphragm blades at the diaphragm position. In addition, since the mechanical and simple diaphragm blade holding mechanism is applied, the diaphragm blade can be stably held without impairing the size reduction of the diaphragm device.
[Brief description of the drawings]
FIG. 1 is a main block configuration diagram of an electronic imaging apparatus showing an embodiment of the present invention.
2 is a developed perspective view of a diaphragm / shutter unit applied to the electronic imaging apparatus of FIG. 1;
3 is a front view of the aperture / shutter portion of FIG. 2;
4 is a schematic cross-sectional view showing an internal structure of a diaphragm actuator applied to the electronic imaging apparatus of FIG. 1;
FIG. 5 is a diagram showing an operating state of the diaphragm device of the diaphragm / shutter section of FIG. 2;
6 is an operation state diagram of a modified example of the diaphragm device of FIG. 5;
7 is a time chart of a CCD electrical imaging signal reading operation when the CCD is a progressive type in the electronic imaging apparatus of FIG.
8 is a time chart of a CCD electrical imaging signal reading operation when the CCD is an interlace type in the electronic imaging apparatus of FIG.
[Explanation of symbols]
4 …… CCD (imaging device)
12 …… System controller (control means)
32 …… Shutter plunger (shutter drive source)
35 ...... Aperture actuator (aperture drive source, aperture blade holding means,
Aperture device)
35a …… Rotor 35b …… Yokes 37, 38
... Shutter blade (shutter device)
39 ...... Shutter lever (shutter device)
41 ...... Aperture blade (aperture device)
42c ...... Protrusions (aperture blade holding mechanism,
Aperture device)
V1 …… First voltage V2 …… Second voltage

Claims (3)

In an electronic imaging device that records subject light that has passed through a lens barrel by converting it into an electrical signal with an imaging device,
A shutter blade disposed in the lens barrel and driven to a position for closing the opening and a position for opening the opening;
A diaphragm blade that is arranged in the lens barrel and moves forward and backward in the optical path to narrow the light beam,
A shutter drive source for driving the shutter blades;
An aperture drive source for driving the aperture blades;
A diaphragm blade holding means for holding the diaphragm blade in a predetermined position;
Prior to charge accumulation by the image sensor, a voltage is applied to the diaphragm drive source to drive the diaphragm blades to a position where the light flux is narrowed, and voltage to the diaphragm drive source prior to charge accumulation by the image sensor The application is stopped, the diaphragm blade is held by the diaphragm blade holding means, and after the charge accumulation by the image sensor is completed, a first voltage is applied to the shutter drive source to bring the shutter blade into a position to close the opening. After driving to move and applying a voltage lower than the first voltage to the shutter drive source to hold the shutter blade in a position to close the opening, signal charge transfer of the image sensor is started. Control means for controlling
An electronic imaging apparatus comprising: The shutter drive source includes a solenoid, a movable iron core that can take a state of protruding from the solenoid, and a state of being sucked by the solenoid, and a return spring that urges the movable iron core in a protruding direction. When the voltage of 1 is applied and the movable iron core is attracted against the urging force of the return spring, the shutter blade is driven to move to a position to close the opening, and the second voltage is applied. By holding the movable iron core in the suction state, the shutter blade is held at a position where the opening is closed, and when the voltage application is stopped, the shutter blade is opened by the urging force of the return spring. The electronic imaging apparatus according to claim 1, wherein the electronic imaging apparatus is driven to move to a position . The diaphragm drive source is a bidirectional electromagnetic actuator capable of selecting an operation direction according to the polarity of energization,
The diaphragm blade holding means is means for holding the diaphragm blade by a stationary holding torque generated between the rotor and the yoke when the yoke coil in the bidirectional electromagnetic actuator is in an unexcited state.
Furthermore, the diaphragm blade is moved to a predetermined position by energizing the bidirectional electromagnetic actuator during photographing, and the diaphragm blade is held at a predetermined position by the diaphragm blade holding means, and the energization to the bidirectional electromagnetic actuator is terminated. Thereafter, the exposure operation and the signal charge transfer operation of the image sensor are performed, and after the exposure operation and the signal charge transfer operation of the image sensor are completed, the aperture blade is moved to an open position, and the aperture blade is held by the aperture blade holding means. 2. The electronic image pickup apparatus according to claim 1 , wherein the electronic image pickup apparatus is controlled by the control means so as to be held in an open position.

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