JPH033488A - Electronic still camera - Google Patents

Abstract

PURPOSE:To adopt aperture device of a fixed aperture switching type and hardly cause durability and deterioration in the aperture accuracy by providing an exposure adjustment control means making the aperture due to aperture means constant, varying the shutter speed so as to adjust and control the exposure of the image pickup means. CONSTITUTION:When an electronic view finder 5 displays a video image with an image pickup means 4, an exposure adjustment control means E uses an aperture means D to make the aperture constant and implements an electronic shutter being a shutter function given to an image pickup means A and a signal processing means B consecutively and the shutter speed is varied to apply adjustment control of the exposure of the image pickup means A. Then when the video image formed by the image pickup element is displayed onto the electronic view finder with the image pickup optical system, it is not required to apply aperture drive thereby hardly causing the deterioration of aperture durability and aperture accuracy and the aperture device of fixed aperture changeover type is adopted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronic still camera, and particularly to an electronic still camera that records an image photographed by an imaging means such as a solid-state image sensor f on a recording medium.

(Prior Art) In recent years, a recording device using a solid-state image sensor such as a CCD and a rotating recording medium such as a magnetic disk has been combined to record still images on the rotating recording medium, and playback of the first-picture image can be performed on a monitor or printer. '7 A child still camera has already been developed.

Unlike cameras that use silver halide film (hereinafter referred to as silver halide cameras), this electronic still camera does not require chemical processing such as development, and images taken can be viewed immediately on a monitor or hard copy. It has many advantages, such as not requiring light shielding of the recording medium and the recording medium being reusable. Furthermore, since an electronic still camera manually captures images using an image sensor, the finder can be an electronic viewfinder. When this electronic viewfinder is used in an electronic still camera,
It is no longer necessary to provide a quick return mirror or the like between the photographic optical system and the image sensor, and in addition, parallax ( parallax)
This has the advantage that problems such as misalignment of the camera and the need for a complicated interlocking mechanism between the front optical system and the finder optical system when the photographing optical system is a zoom lens do not occur.

[Problem to be solved by the invention]

As described above, in the conventional example, when an electronic still camera employs a 'Y' viewfinder, the image formed on the image sensor by the photographing optical system is incident on the image sensor while being reflected on the electronic view finder. It is necessary to adjust the aperture so that the amount of light is constant. By the way, if you keep moving the aperture in this way, you will have to drive the aperture for a much longer period of time than if you only drive the aperture during shooting, which will wear out the aperture blades (described later) and cause dust to build up inside the S-shading optical system. Occurrence or comparison 1? This may lead to deterioration of the degree of damage.

This requires an aperture mechanism that is much more durable than an aperture that is driven only during photographing, which poses a problem that increases the cost of the device.

In addition, an inexpensive fixed aperture switching type aperture mechanism that moves a member with a very limited number of punched holes onto and out of the optical axis of the photographic optical system should be adopted in an electronic still camera that uses the finder as an electronic viewfinder. The problem was that it became impossible to do so.

This invention was made in order to solve the problems of the conventional example as described above, and eliminates the need to drive the aperture when the image formed on the image sensor by the photographing optical system is displayed on the electronic viewfinder. In addition, it is also possible to adopt a fixed aperture switching type aperture mechanism, thereby making it possible to create a highly reliable and low-cost electronic still camera. It is [1 purpose] to provide.

(Means for Solving the Problem) Therefore, in the present invention, a photographing optical system, a photographing means for electrically converting a subject image formed by the photographing optical system into a video signal, and a +ff video signal - ); recording means for recording the video signal; aperture means; and an electronic viewfinder.
When an image is projected by the image pickup means, the aperture value of the aperture means is kept constant, and (l) an electronic shutter with a shutter function provided in the image pickup means and the signal processing means is continuously operated, and the shutter speed is adjusted. The above object is achieved by comprising an exposure amount adjustment control means for adjusting and controlling the exposure amount of the image pickup means by changing the exposure amount.

Further, in the above invention, the above object is achieved by setting the aperture value by the aperture means in an open state.Furthermore, in the above invention, the exposure amount adjusting means is configured to set the aperture value by a plurality of specified aperture values by r/steps. The aperture value is set, and the electronic/shutter of the shutter function provided in the first stage of imaging and the signal processing means is performed continuously, and the exposure amount of the imaging means is determined by the combination of this shutter speed and the specified aperture value: JJ The aim is to achieve the above objective by

(Function) In the electronic still camera according to the present invention, when an image is projected by the electronic viewfinder or the image pickup means, the aperture value is kept constant by the aperture means by the exposure adjustment control means, and the aperture value is kept constant by the aperture means and the image pickup means and the signal processing 7'- An electronic shutter, which is a shutter function provided on a stage, is operated continuously, and the exposure amount of the imaging means is adjusted and controlled by changing the shutter speed.

Further, in the electronic still camera according to the present invention, the aperture value is set to an open state by the aperture means.

Further, the electronic still camera according to the present invention has an exposure amount
g! The control means sets the aperture value to a plurality of specific aperture values using the aperture means, continuously operates an electronic shutter, which is a shutter function provided to the imaging means and the signal processing means, and captures an image by combining the shutter speed and the specific aperture value. The exposure amount of the means is adjusted and controlled.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

Fig. 1 is a block diagram showing the concept of an electronic still camera that is an embodiment of the present invention, Fig. 2 is a block diagram showing the circuit configuration of this embodiment, and Fig. 3 is an aperture of the electronic still camera of this embodiment. No. 41 is an exploded perspective view of the turret diaphragm of this embodiment. FIG. 5 is a perspective view of the turret diaphragm of this embodiment. FIG. 5 is a flowchart for controlling operations.

In FIGS. 1 and 2 of the drawings, A is an imaging means, which is composed of an image sensor 1-4 and a CCD control circuit 33, and converts a subject image formed by an imaging optical system 1 into an electrical video signal. It is a means. Reference numeral B denotes a signal processing means composed of a camera control circuit 10, a signal processing system such as a release button 1.2, and the like. C is a recording stage, which is composed of a recording section 9 and a recording section control circuit 34, and is means for recording a video signal. D is an aperture means, which includes an aperture 2 and an aperture control circuit 3.
It consists of E is an exposure amount adjustment control means, which is composed of a camera control circuit 10 and an electronic viewfinder 5.
When the image capturing means A is projecting an image, the aperture value of the aperture means is kept constant, and an electronic shutter (not shown), which is a shutter function provided to the image capturing means A and the signal processing means B, is continuously operated; This is a means for adjusting and controlling the exposure amount of the imaging means A by changing the shutter speed.

Further, 6 is a lens of the finder section, and 7 is a switch that serves both as a camera power source and a mode changeover.

Further, in FIG. 3, reference numeral 11 denotes an aperture drive motor, which is controlled by the aperture control circuit 3. As shown in FIG. 12 is a pinion gear, and 13 is a diaphragm windmill, which are supported rotatably around the optical axis x-x. Also Binion l & Jt
A heavy portion 13a that engages with the wind turbine 112 is provided on the circumference.The rotational force of the motor 11 is transmitted to the throttle windmill 13 through this portion.

Reference numeral 14 denotes a plurality of aperture blades (only one of the five blades is shown on the Japanese side), each of which has two dowel blades 14a protruding from it. Reference numeral 15 denotes an aperture cam plate, and five cam grooves corresponding to the number of aperture blades are protruded equally in the circumferential direction centering on the optical axis x-x.

Here, each dowel bin 14a of each aperture blade 14 is fitted into a bin support hole of the aperture windmill 13 and a corresponding cam groove 15a of the aperture cam plate 15, and the rotation of the aperture windmill 13 causes the plurality of aperture blades 14 It is configured to change the aperture diameter (area) formed by the aperture.

Next, the operation of this embodiment will be explained using FIGS. 1 to 5.

First, when the camera switch 7 is operated and the power is turned on, an image formed on the image sensor 4 by the camera control circuit 10 is displayed on the electronic viewfinder 5. At this time,
The aperture 2 is in an open state. And the image sensor 4
Light incident on? By changing the shutter speed of the electronic shutter, the brightness of the image displayed on the electronic viewfinder 5 is adjusted to be constant. here,
Photography: When a person decides on the composition using the electric Y-viewfinder 5 and presses the release button (not shown) to take a photograph, switch 1 (second rA) is turned on after the release button has not been pressed half a stroke. A photometry unit (not shown) determines the brightness of the subject h< il! 1 is determined.

When the release button is further pressed, switch 2 (FIG. 2) is turned on. Then, when the ON state of the switch 2 is confirmed by the camera control circuit 10, the photographing operation is started. First, the motor 11 is rotated to move the aperture 2 so that the aperture value is determined depending on the brightness of the subject or the aperture value is set in advance by the JMJJ person. Exposure is then performed using an electronic shutter at a shutter speed determined by the brightness of the subject or a shutter speed set in advance by the photographer. Then, the video signal accumulated in the image sensor 4 at this time is transferred to the recording section by the camera control circuit 10, and recorded by the recording section control circuit 34 on the unrecorded part of the recording medium. Further, the aperture 2 is returned to the state before the release, and the photographing is completed.

Further, when a camera operating member such as a release button is not operated for a certain period of time, the power to the electronic viewfinder 5 is turned off to prevent the power from being consumed. however,
When the camera operation member is operated in this state, the electronic viewfinder is turned on again to return to the original state.

Next, the mechanism of the diaphragm 2 of this embodiment will be explained with reference to FIGS. 4 and 5 as examples. FIG. 4 shows a turret diaphragm described in the prior application GAF1466, which can be used in this embodiment. This aperture is open aperture, intermediate aperture,
The electromagnetic control means is de-energized and rotates normally for each of the three minimum aperture values.

It is configured to control X1lIJ corresponding to three states of inversion. Further, in order to increase the number of aperture stages, turret aperture control as shown in FIG. 5 is used.

The turret diaphragm mentioned above will be explained with reference to FIG. 4 of the drawing. Reference numeral 23b denotes a bottle that holds an aperture plate 24 installed in the camera fixing part so as to be rotatable perpendicular to the optical axis. 23c
is a bottle implanted in a fixed part that engages with the stopper part 24d of the aperture plate 24 and restricts rotation of the aperture plate. The aperture plate 24 is provided with an open aperture hole 24a, an intermediate aperture hole 24b, and a small aperture hole 24c as aperture openings.
In the aperture standby state, the center of the open aperture hole 24a is aligned with the optical axis. 24d is a part of the stopper. 24e
is a gear portion of the aperture plate 24, which is engaged with the gear 28a. 24f is a bottle installed in the aperture plate 24. 26
is a spring attached to the bottle 23b and biases the aperture plate 24 to the aperture standby position. Reference numeral 28 denotes an aperture drive motor, which engages with the aperture plate 24 via a gear 28a attached to a rotating shaft.

Next, the operation of this turret diaphragm will be explained using FIG. 4. In the aperture standby state, the motor 28 is not energized, and the center of the opening hole 24a of the aperture plate 24 is aligned with the optical axis by the spring 26.

When driving the aperture, when the motor 28 is energized and the rotating shaft of the motor rotates in the direction of arrow A, the aperture plate 24 rotates until the stopper portion 24d collides with the bottle 23c. At this time, the center of the intermediate aperture hole 24b is set to coincide with the center of the optical axis. And the spring 26 is a dowel 23c
When the photographing is finished and the power to the motor 28 is cut off, the aperture plate 24 is rotated by the force of the spring 26 and returned to the aperture standby position. The motor 28 is energized in the opposite direction, and the rotation axis of the motor 28 is rotated in the direction of arrow B.
When the aperture plate 24 rotates in the direction, the aperture plate 24 rotates until the stopper portion 24d and the bottle 23c collide, and at this time, the center of the small aperture hole 24c coincides with the optical axis. And motor 28
When the current is turned off, the force of the spring 26 causes the aperture plate 24 to return to the aperture standby position.

The use of such a turret diaphragm is a very effective means for reducing the cost of electric still cameras, which have severe aperture distortion.

In the embodiments so far, the aperture is open at the aperture standby position, but if the aperture value is advantageous due to the configuration of the aperture mechanism, a specific aperture value may be set as the aperture standby position.

In addition, if you do not want to use the shutter speed above a certain value with the configuration of the electronic shutter, you can set the aperture standby position not in one place but in multiple places, and set a small aperture in one of them, so that the shutter speed can be adjusted within a certain range. It can be stored inside. In this way, when the electronic viewfinder 5 is powered on, the aperture value may be changed depending on the brightness of the subject.

Next, regarding one control of the operation of this embodiment described above, focusing on the exposure amount adjustment control means E, using the flowchart of FIG. 6 and referring to FIGS. 1 and 2, tfllQ
I will explain to you.

In FIG. 6 of the drawing, first, the power is turned on and this flow starts. In step 61, the image sensor and electronic viewfinder are turned on, and in step 62, the switch l is turned on.
Determine whether the button is pressed, and if it is pressed, proceed to step 6.
If the button has not been pressed, the process returns to step 62. In step 63, photometry, distance measurement, voltage power supply, and auto white balance are confirmed, and the process proceeds to step 64. In step 64, the aperture value is set to be constant or a plurality of specific aperture values, the shutter speed determined by the brightness of the subject or the shutter speed set in advance by the photographer is performed, and the amount of movement of the optical system is also calculated. Then, the process proceeds to step 65 and it is determined whether switch 2 is ON. If switch 2 is ON, the process proceeds to step 67. Switch 2 in step 65
If it is not ON, the process proceeds to step 66, in which it is determined whether switch 1 is ON, and if it is ON, the process proceeds to step 66.
Return to step 5, and if it is not ON, return to step 62. In writing step 67, the charge of the image sensor is discharged, the aperture is moved,
Move the optical system and take a picture in step 68 (charge storage 8i)
do. Then, the charge is transferred in step 69, recorded in step 7o, the aperture is opened in step 71, and step 6
Return to 2.

As explained above, in this embodiment, when the electronic viewfinder projects an image formed on the image sensor by the photographing optical system, the aperture value is set to a certain value, and the exposure amount at this time, that is, the image Adjustment of the charge accumulated in the element is achieved by continuously performing a shutter function provided in the signal processing of the image pickup element and camera, a so-called electronic shutter.

〔Effect of the invention〕

As explained above, according to the present invention, there is no need to drive the aperture when the image formed on the image sensor t by the photographing optical system is displayed on the electronic viewfinder, resulting in deterioration of aperture durability and aperture accuracy. In addition, it is also possible to adopt a fixed aperture switching type aperture mechanism. Therefore, it is possible to provide a highly reliable and low-cost electronic still camera.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the concept of an electronic still camera which is an embodiment of the present invention, Fig. 2 is a block diagram showing the circuit structure of this embodiment, and Fig. 3 is an exploded perspective view of the aperture section of this embodiment. 4 is a perspective view 1 illustrating the turret diaphragm of this embodiment, FIG. 5 is a perspective view 2 illustrating the turret diaphragm of this embodiment, and FIG. 6 is a flowchart for controlling the operation of this embodiment. be. A: Imaging means B: Signal processing means C: Recording means D: Aperture means E: Exposure adjustment control means 1 ...1M shadow-end optical system...Aperture 3...Aperture control circuit 4...Image sensor f5...Electronic viewfinder 7. ...Power and mode selector switch 10--
...Camera control circuit 32...Electronic viewfinder *iag circuit 3
3...CCD i control circuit In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) a photographing optical system; a photographing means for electrically converting a subject image formed by the photographing optical system into a video signal; a signal processing means for processing the video signal; and a recording means for recording the video signal. and an aperture means; and an electronic viewfinder; when the electronic viewfinder projects an image taken by the image pickup means, the aperture value of the aperture means is kept constant; An electronic still comprising an exposure amount adjustment control means for continuously operating an electronic shutter having a shutter function provided in a signal processing means and adjusting and controlling the exposure amount of the imaging means by changing the shutter speed. camera. (2) The electronic still camera according to claim 1, wherein the aperture value of the aperture means is set to an open state. (3) The exposure amount adjustment means sets the aperture value by the aperture means to a plurality of specific aperture values, continuously performs an electronic shutter with a shutter function provided in the imaging means and the signal processing means, and sets the aperture value by the aperture means to a plurality of specific aperture values, and continuously performs an electronic shutter with a shutter function provided in the imaging means and the signal processing means, and 2. The electronic still camera according to claim 1, wherein the exposure amount of said image pickup means is adjusted in combination with a value.