JPH02151179A - Electronic still camera - Google Patents

Abstract

PURPOSE:To improve the stop accuracy and to decrease the stop time at the still mode by setting a minimum stop diameter at the movie mode less than the minimum stop diameter at the still mode. CONSTITUTION:With a mode changeover switch 20 set to the movie mode, a mirror 8 is jumped up and a shutter 6 is opened. Then a luminous quantity incident on an image pickup element 4 is discriminated as a charge stored into the image pickup element 4 within a unit time and if there is any change in the incident luminous quantity, a motor 11 is driven to switch the diaphragm 2 in a way that the quantity of charge stored in the image pickup element 4 is constant value. Then the movie video image obtained by the image pickup element 4 is outputted from the output terminal. Thus, the camera copes properly with both the still mode and the movie mode and the stop accuracy and the control performance are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to aperture control of an electronic still camera, particularly an electronic f-still camera that records images captured by a solid-state image sensor or the like on a recording medium. This relates to method 1.

[Conventional technology]

1, CCD (Hf coupling device), etc.
A still image is recorded on the rotating recording medium by combining a single image sensor γ and a recording device using a rotating recording medium such as a magnetic tape. An electronic still camera is being developed.

In the electric still camera, the characteristics of the image sensor r are used to continuously read out the electrons of the image sensor r-, with the shutter open, to capture not only still images but also moving images. It also has the feature of being able to take pictures.

[Invention or problem to be solved]

Furthermore, in an electric still camera equipped with a still mode and a movie mode, in the movie mode, changes in the amount of light incident on the image sensor are determined by changes in the charge accumulated on the image sensor within a unit time. Then, the aperture is opened and closed so that the electrons::i accumulated within this unit time become constant.

In addition, in the still mode, the aperture is open at all times other than the darkest mode, but in the darkest mode, the aperture is narrowed down to a predetermined aperture value and a known shutter drive is performed. The aperture was configured to return to the 11th open state after the end of photography.

However, in the movie mode, the charge accumulated on the image sensor t is read out within a fixed time, which is the same as the shutter speed being constant. 5. The amount of electric charge discharged needs to be controlled by the aperture diameter, so it was necessary to always narrow down the aperture to a small diameter in the J1.

In addition, in still mode (star shadow), the shutter speed is adjusted to (II) H, so there is no need to adjust the extremely small aperture diameter as in movie mode. In addition, in general, the latitude of the i+'+I body image sensor f- is extremely narrow, so it was necessary to perform high-precision aperture control. In particular, it generally becomes more difficult to maintain a predetermined aperture accuracy as the aperture diameter becomes smaller.

The present invention has been made in view of the above-mentioned problems, and is suitable for both still mode and movie mode. The aim is to provide a still camera for the 't' period.

[-stage to solve the problem]

Therefore, in the present invention, a photographing optical system, an aperture mechanism, and an imaging stage F for converting the image of the Buddha image formed by the photographing optical system into an electric image fTH; 1. In an electric still camera that has a recording F stage for recording movie images, a throughput, and a mode switching means for switching between movie modes, the minimum aperture diameter in movie mode is set to the still mode. By configuring the aperture diameter to be set to be larger than the minimum aperture diameter for the first time, it is intended to achieve the eleventh objective of 111f.

(A'1 River) With the configuration as described in 1-1 below, in the electric still camera according to the present invention, in the movie mode, changes in the light I11 are stored in the image element 411 in about 1 time. The diaphragm is opened and closed so that the load accumulated within this unit time remains constant due to the change in rfi 4::l. The aperture is controlled from an open state to a constantly small aperture diameter or a fully closed state.

Also, the small aperture diameter required for Still Movie 1 Ji Samurai is compared to movie mode; 1. It is convenient to maintain it in the control box 11!1.

With the above, it is possible to appropriately correspond to both still mode and movie mode, and the aperture is 111 degrees and controllability is f.
An electric still camera equipped with a disappointing aperture mechanism can be obtained.

〔Example〕

Hereinafter, the present invention will be explained based on Examples J and L.

1 to 4 are explanatory diagrams of an embodiment according to the present invention.

Fig. 1 is a schematic diagram of the configuration of an embodiment of the f-still camera according to the present invention, Fig. 2 is a block diagram of the camera of Fig. 1, and Fig. 3 is an exploded view of the aperture section of the camera of this embodiment. FIG. 4, which is a perspective view, is a comparison diagram of the range of use of the aperture in the mustard of the camera of this embodiment.

(414 composition) In FIG. 1, 11 is a photographing optical system such as a lens, and 2 is an aperture, which is controlled by a comparison circuit 3. 4 is an image sensor r such as a CCD, and the camera 1LII (
S is a camera; 1i (I is connected to the wholesale circuit 5 by a line -); 6 is a shutter, which is controlled by a shutter control circuit 7 shown in Fig. 2; Reference numeral 8 designates a mirror, which is controlled by the control circuit 9 to move to the position indicated by the broken line; 1O controls the finder.

In addition, in FIG. 3, 11 is an aperture drive phase motor,
The aperture control circuit 3 controls 1tlJ. 12 is a pinion gear, and 13 is an aperture shaft, which is supported rotatably around the optical axis x-x. Also pinion tooth width 1
A south +1ε part 13a that meets +ka 2 is provided on the circumference l, and the rotational force of the motor 11 is throttled through this part to reduce the wind Ilt l 3
Communicate to. Reference numeral 14 has a plurality of aperture blades (the government only made one of the five blades small), each of which has two twelve blades 14a protruding from it. 15 is the aperture cam plate,
Fully 5 cams corresponding to the number of aperture blades, optical/Itx-x
They protrude equally in the circumferential direction around the center.

Here, each toll pin 14a of the valley aperture blade 14 is connected to a pin support hole of the aperture windmill 13 and an aperture cam plate 15, respectively.
It is fitted into the corresponding cam 1M portion 15a, and is configured to change the diameter (area) of the aperture formed by the plurality of aperture blades 14 as the aperture windmill 13 rotates.

(motion) Next, the operation in the above configuration will be explained.

When the mode selector switch 20 in FIG. 2 is set to ``movie mode'', the mirror 8 is
It is in a repelled state (shown by broken lines in FIG. 1), and the shutter 6 is also in an open state. At this time, the light 1t incident on the image sensor f4 is transmitted to the image sensor f within a unit time.
The charge stored in the image sensor F4 when there is a change in the incident light 1d is determined as the charge that is transferred to the image sensor F4! The diaphragm 2 is opened and closed by the motor 11 so that the value becomes +1 or a certain constant value. Then, 1! due to image sensor r4! The converted movie image is outputted from an output terminal r- (not shown). .

When the mode selector switch 20 is set to the "still mode", the mirror 8 is in the lowered state (solid line in Figure 1), the shutter 6b is closed, and the diaphragm 2 is also closed. At this point, when the photographer decides on the composition and presses the release button (not shown) to take a photo, the release button is released.
- At the stage when the stroke is pressed, the release switch 116 shown in FIG. 2 is turned on, and the brightness of the subject is measured by the photometry circuit 17. When the release button is further pressed, the release switch 217 is turned on, and when the camera control circuit 5 confirms that the release switch 217 is on, a photographing operation is started. In addition, the second
2 in the diagram! shows various large and small circuits.

First, the motor 11 in FIG. 3 rotates simultaneously until the aperture value is determined depending on the brightness of the subject, or the aperture value is set by the photographer, and the aperture is stopped down. At the same time as this narrowing down, the mirror 8 in FIG. 1 is repelled, and when both operations are completed, the shutter 6 is opened and closed, and the image 113 is stored as a charge in the image sensor (-4). , this video signal is transferred from the camera control circuit 5 to an unspecified recording section;
recorded by. Further, the aperture 2 and the mirror 8 are restored to the state before the release, and the end of the first shadow γ is reached.

FIG. 4 contrasts and outlines the aperture use range in the valley mode.

(Other Examples) When shooting in still mode, more accurate exposure may be achieved by performing 111 metering after stopping the aperture and finely adjusting the shutter speed. Of course, the motor used may be a stepping motor or the like. Also,
Instead of the fine lens 10 and mirror 8 shown in Fig. 1, it is possible to use a TV fine lens, and furthermore, by providing the image sensor (4 and f7; 4 processing system with a shutter function) , the shutter 6 as shown in FIG.
, it doesn't support Z.

By the way, to give a supplementary explanation about the aperture in movie mode and the aperture time in still mode, in movie mode, the aperture opens and closes depending on the change in the incident light to the image sensor. In order to supplement it and keep it at a constant value, the aperture granularity required for the aperture range during still mode photography is not required during movie mode. Furthermore, in the still mode, the smaller the diameter of the aperture, the greater the movement of the aperture blades at the time of stopping down, so it takes time to stop down.

(Efficacy of the Invention) As explained above, according to the present invention, the 7tt IF
The JIjtMe still camera is configured to set the minimum aperture diameter in movie mode to less than the minimum aperture diameter in still mode, so whether it is necessary in movie mode or still mode 1! There is no need for transgression t1, ν, and in a still camera with low latitude,
To provide a 7u, f still camera which does not need to use a small aperture range in which it is difficult to maintain aperture precision in still mode, has good aperture granularity, and has short aperture time in still mode. was completed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the electronic f-still camera according to the present invention, Fig. 2 is a block diagram of the camera of Fig. 1, and Fig. 3 is an exploded perspective view of the aperture section of the camera of this embodiment. FIG. 4 shows a comparison of the aperture usage range in each mode of the present example camera. 1... Shooting optical system 2... Aperture 3... Aperture control circuit 4... Imaging device 5... Camera control circuit 6. ...Shutter 8 ... Mirror 10 ... Footprinter 11 ... Motor 14 ... Aperture blade 20 ... Motor 1' IRJ 11
Ganjin Canon Co., Ltd. C) C Tsuya

Claims (1)

[Claims] a photographing optical system, an aperture mechanism, an imaging means for converting a subject image formed by the photographing optical system into an electrical video signal, a recording means for recording the video signal, a still mode and a movie mode. 1. An electric still camera having a mode switching means for switching between modes, wherein the minimum aperture diameter in the movie mode is set to be equal to or less than the minimum aperture diameter in the still mode.