JP3847931B2 - Light control device and camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light amount adjusting device used for a video camera, a digital still camera, and the like.
[0002]
[Prior art]
A moving image light amount adjusting device that continuously changes the aperture from an open state to a fully closed state is used for a moving image capturing camera such as a video camera. On the other hand, a still image shooting camera such as a digital still camera uses a still image light amount adjustment device that can switch between two positions of an open state and a small aperture state (for example, F8) and can also perform a shutter operation. There is.
[0003]
[Problems to be solved by the invention]
However, since the function required with respect to the amount of light regulatory differs between a moving image and a still image, moving image and the camera capable of both still image photographing, a separate quantity regulatory device for still image and a moving image It was necessary to install.
[0004]
Accordingly, an object of the present invention is to provide a light amount adjustment device that can be used for both moving image and still image applications.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, in a camera capable of adjusting the size of the aperture opening by relatively moving a plurality of aperture blades, and capable of moving image shooting and still image shooting, the light amount The adjusting device includes: a first relative position where the continuously variable aperture portion of the aperture blades forms an open aperture; and a second relative position where the continuously variable aperture portion forms a fully closed aperture. By adjusting the size of the aperture opening by the continuously variable aperture, and driving the plurality of aperture blades to a third relative position, The aperture stop is made a small stop by different fixed stop portions . Then, the camera determines whether to shoot a moving image or a still image, and when it is determined to shoot a moving image, the diaphragm blades are moved between the first relative position and the second relative position to move the aperture. the size of the aperture is continuously varied to control so that the light amount adjusting device, when it is determined that the still image shooting relative positions of the plurality of diaphragm blades in said third relative position between the first relative position controlling the light amount adjusting device as switching Ru.
[0006]
According to the camera configured in this manner, the light amount adjusting device is controlled so that the aperture opening continuously changes between the open aperture and the fully closed state during movie shooting, and the open aperture and the small aperture are controlled during still image shooting. Since the light amount adjusting device is controlled so as to be switched to, it is possible to perform moving image shooting and still image shooting only by providing one light amount adjusting device.
[0007]
Note that during still image shooting, a plurality of aperture blades may be switched from the first or third relative positional relationship to the second relative positional relationship to perform a shutter operation.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows a light amount adjusting apparatus according to the first embodiment of the present invention. In this figure, 1 is a 1st aperture blade, 2 is a 2nd aperture blade. Each of the diaphragm blades 1 and 2 is formed with long holes 1-c and 2-c into which shaft portions 6a and 6b formed at the end portions of the drive arm 6 that swings about the swing axis O are fitted. Has been. The diaphragm blades 1 and 2 are respectively provided with guide grooves 1-d and 2-d into which guide pins 4 and 5 formed on a base plate (not shown) are fitted. Therefore, when the drive arm 6 is driven to swing around the swing axis O by an actuator such as a motor (not shown), the diaphragm blades 1 and 2 are guided in the vertical direction in the figure while being guided by the guide pins 4 and 5. Moving.
[0009]
Further, the diaphragm blades 1 and 2 each have a continuously variable diaphragm section 1-b, 2-b that enables continuous diaphragm opening adjustment between open and fully closed, and a small diaphragm (for example, F8). ) To form the fixed throttle portions 1-a and 2-a. Reference numeral 3 denotes a fixed open opening formed in the base plate.
[0010]
Next, the operation of the light quantity adjustment device configured as described above will be described. First, as shown in FIG. 1A, when the drive arm 6 is swung to the position of the angle A, the aperture blades 1 and 2 are formed with open apertures by the continuously variable aperture portions 1-b and 2-b. (A first relative positional relationship in the claims).
[0011]
As shown in FIG. 1B, when the drive arm 6 swings to the position of the angle B, the aperture blades 1 and 2 are fully opened by the continuously variable aperture portions 1-b and 2-b. (A second relative positional relationship in the claims).
[0012]
Further, as shown in FIG. 1C, when the drive arm 6 swings to the position of the angle C, the fixed diaphragm portions 1-a and 2-a overlap the two diaphragm blades 1 and 2 to form a small diaphragm. The positional relationship (the third relative positional relationship referred to in the claims) is established.
[0013]
Here, when the drive arm 6 is continuously driven between the angle A and the angle B, the size of the aperture opening is continuously adjusted by the continuously variable aperture portions 1-b and 2-b of the aperture blades 1 and 2. Can be changed.
[0014]
Further, when the drive arm 6 is driven in a two-position switching manner between the angle A and the angle C, the fully-open aperture formed by the continuously variable aperture portions 1-b, 2-b of the aperture blades 1, 2 and the fixed aperture portion 1 Stepwise switching with the small aperture formed by -a and 2-a can be performed.
[0015]
For this reason, when this light amount adjusting device is attached to a camera capable of both moving image shooting and still image shooting, control for moving the drive arm 6 continuously between the angle A and the angle B in the moving image shooting mode (moving image) If a control (still image aperture mode) is performed to switch and drive the driving arm 6 at two positions of the angle A and the angle C in the still image shooting mode, an appropriate image sensor or the like corresponding to the shooting mode is performed. The amount of incident light can be adjusted.
[0016]
Further, when the two-position switching control (still image shutter mode) is performed so as to drive the driving arm 6 from the angle A or the angle C to the angle B, an operation of switching from the fully open aperture or the small aperture state to the fully closed state at once. Shutter operation can be performed, and it can be used as a shutter for still image shooting.
[0017]
Next, the operation of the moving image / still image camera equipped with the light amount adjusting device of the present embodiment will be described with reference to the flowchart of FIG. This flowchart explains the operation of a camera using an all-pixel readout type CCD. That is, the operation of the moving image aperture mode and the still image aperture mode (two-position switching) will be described.
[0018]
First, at {circle around (1)}, information on whether the future shooting is moving image shooting or still image shooting is fetched. Next, in (2), a moving image / still image is determined. Here, in the moving image aperture mode, moving image shooting is performed in (4) while continuously adjusting the amount of light to the aperture based on the luminance information of the CCD in (3).
[0019]
On the other hand, in the still image aperture mode, when the shutter button is half-pressed in (5), the CCD accumulation time and aperture value are determined based on the CCD brightness information in (6) and the aperture is automatically adjusted. . Further, when full-pressing of the shutter button is detected at {circle around (7)}, CCD pixel information is read after the predetermined CCD accumulation time has passed at {circle around (8)}, and still image shooting is finished at {circle around (9)}.
[0020]
Next, the operation of the camera using the sequential readout type CCD will be described with reference to the flowchart of FIG. That is, the moving image aperture mode and the still image shutter aperture mode (shutter operation) will be described.
[0021]
First, at {circle around (1)}, information on whether the future shooting is moving image shooting or still image shooting is fetched. Next, in (2), a moving image / still image is determined. Here, in the moving image aperture mode, moving image shooting is performed in (4) while continuously adjusting the amount of light to the aperture based on the luminance information of the CCD in (3).
[0022]
On the other hand, in the shutter mode for still images, when the shutter button is half-pressed in (5), the CCD accumulation time and aperture value are determined based on the CCD brightness information in (6), and the aperture is automatically adjusted. Do. Further, when the shutter button is fully pressed in (7), the aperture is closed and the CCD pixel information is read out after the predetermined CCD accumulation time is exceeded in (8), and still image shooting is finished in (9). .
[0023]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a camera capable of performing both a light amount adjusting operation suitable for moving image shooting and a light amount adjusting operation suitable for still image shooting with a single light amount adjusting device . In particular, in the light amount adjusting device provided in the camera of the present invention, the configuration of the diaphragm blade function is devised by combining the aperture blade shape for moving image shooting and the diaphragm function for still image shooting. ) And there is no increase. Accordingly, it is possible to configure a camera that performs moving image shooting / still image shooting in a compact and inexpensive manner, and to perform light amount adjustment suitable for moving image shooting / still image shooting with simple control.
[Brief description of the drawings]
FIG. 1 is an operation explanatory diagram of a light amount adjusting apparatus according to a first embodiment of the present invention.
FIG. 2 is an operation flowchart of a camera equipped with the light amount adjusting device (when the CCD is of an all-pixel readout method).
FIG. 3 is an operation flowchart of a camera equipped with the light amount adjusting device (when a CCD is of a sequential readout method).
[Explanation of symbols]
1, 2 Aperture blades 1-a, 2-a Fixed aperture portions 1-b, 2-b Continuously variable aperture portions 6 Drive arm

Claims (2)

A camera that has a light amount adjusting device that adjusts the size of the aperture opening by relatively moving a plurality of aperture blades, and is capable of shooting a moving image and a still image,
The light quantity adjusting device includes: a first relative position where the continuously variable aperture portion of the aperture blades forms an open aperture; and a second relative position where the continuously variable aperture portion forms a fully closed aperture. By adjusting the size of the aperture opening by the continuously variable aperture section, and driving the plurality of aperture blades to a third relative position, thereby continuously variable apertures of the plurality of aperture blades. The diaphragm aperture is a small diaphragm by a fixed diaphragm section different from the section ,
The camera determines whether moving image photographing or still image photographing, when it is determined that moving image shooting of the aperture stop is moved between said second relative position of said plurality of diaphragm blades and the first relative position the size of controls so that the light amount adjusting device is continuously changed, when it is determined that the still image shooting to switch the relative positions of the plurality of diaphragm blades in said third relative position between the first relative position A camera that controls the light amount adjusting device. When the camera performs a shutter operation when it is determined that still image shooting is performed, the plurality of aperture blades move from the first relative position to the second relative position , or from the third relative position to the second relative position. The camera according to claim 1, wherein the light amount adjusting device is controlled to be switched to

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