JPH01218272A - Electronic still camera apparatus - Google Patents

Abstract

PURPOSE:To clearly record from an object moving at high speed to a still object by obtaining optimum shutter speed conforming to the movement of an object. CONSTITUTION:In an electronic still camera apparatus 11, a video signal obtained form a solid-state image pickup element 3, which is operated after the depression of a shutter button 3a, is inputted to a motion detecting circuit 12, and the motion of the object is detected by a motion detecting circuit 12. Conforming to the detected motion of the object, a shutter speed control circuit 7 is driven, the shutter speed of the solid-state image pickup element 3 is changed, and the optimum shutter speed conforming to the motion of the object is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electronic still camera device that can obtain an appropriate shutter speed in accordance with the movement of a subject.

[Prior Art] The conventional electronic still camera device l shown in FIG. The image information for one screen accumulated in the form of electric charges in the solid-state image sensor 3 is
A configuration is adopted in which reading takes a fixed reading time. The image information read out from the solid-state image sensor 3 is converted into a signal form compatible with the recording format by the video processing circuit 4, and then recorded on a magnetic disk 6 that rotates at a constant speed via a magnetic head 5. be done. In addition, since a certain amount of start-up period is required to rotate the magnetic disk 6 at a constant speed, when the shutter button 3a starts to be pressed, the motor 6a for driving the magnetic disk is started immediately, and the motor 6
When the rotational speed force of a reaches a predetermined speed, the lock of the shutter button 3a is released.

[Problems to be Solved by the Invention] The above-mentioned conventional electronic still camera device l has a solid-state camera device 3.
By switching the readout time of the charges accumulated in
A shutter speed control circuit 7 is connected to the solid-state image sensor 3 so that the shutter speed can be varied. However, in this case, the shutter speed is selected by the photographer at his/her own discretion by operating the manual changeover switch 8. When performing the opposite camera operation, it is necessary to switch the changeover switch 8 one by one, making it difficult to concentrate on basic tasks such as setting the angle of view and composition, especially when you want to release the shutter continuously. was holding.

[Means for Solving the Problems] The present invention has solved the above problems, and is an electronic system that records on a rotating magnetic disk a screen worth of video signals obtained from an image sensor when the shutter button is fully pressed. The still camera device includes an imaging device with a variable shutter speed that operates from the start of pressing the shutter button or before that, and a time difference between a video signal obtained from the imaging device until or after the shutter button is pressed all the way down. A motion detection circuit that detects the movement of a subject, and a shutter speed control circuit that varies the shutter speed of the solid-state image sensor according to the movement of the subject detected by the motion detection circuit to obtain an optimal shutter speed. It is characterized by being configured with the following features.

[Operation] According to the present invention, a motion detection circuit detects the movement of a subject from a video signal obtained by an image sensor that operates at or before the start of pressing the shutter button, and adjusts the image sensor according to the detected movement of the subject. By varying the shutter speed, an optimum shutter speed can be obtained under any imaging conditions.

[Example] Hereinafter, an example of the present invention will be described with reference to FIG. 1. FIG. 1 is a circuit diagram showing an embodiment of an electronic still camera device of the present invention.

In FIG. 1, the electronic still camera device 11 has a shutter button 3.
A motion detection circuit 12 that detects the motion of the subject by taking the time difference of the video signal obtained from the solid-state image sensor 3 until or after pressing the button a.

The shutter speed of the solid-state image sensor 3 when the shutter button 3a is fully pressed is changed according to the movement of the subject detected by the motion detection circuit 12.

The motion detection circuit 12 includes a field memory 13 as a delay means, a difference circuit 14 that calculates the difference between the video signal of l fields before delayed by the field memory 13, and the current video signal, and the output of the difference circuit 14. A plurality of comparison circuits 15 that compare the field difference signal with a predetermined comparison standard set in advance and determine the shutter speed based on the magnitude of the field difference signal. ．． 15. ,,． Consists of 156. Since the comparison standards of the comparison circuits 15+, 15t, . . . , 15n are made to differ in stages, a positive comparison error output can be obtained in accordance with the degree of movement of the subject as a whole. Therefore, the shutter speed control circuit 7 determines the optimum shutter speed according to the number of positive comparison error outputs, and presses the shutter button 3a.
The charge readout time of the solid-state image sensor 3 is switched when or immediately after the charge is pushed out.

Here, when photographing a stationary subject, there is almost no difference between the video signal from l field before and the current video signal stored in the field memory 13 in the motion detection circuit 12 during the period when the shutter button 3a is pressed. Since there is no comparison circuit 15. −
15n error outputs are all negative. As a result, the shutter speed control circuit 7 determines from this error output that the subject is stationary, and sets the shutter speed to the slowest 1/60 second. On the other hand, when photographing a high-speed subject, the field memory 13 in the motion detection circuit 12 stores a difference between the video signal from one field before and the current video signal, depending on the speed of the subject's movement. occurs, some comparison circuits 15. -15K (however, k
≦i), the error output is positive. As a result, the shutter speed control circuit 7 determines the movement of the subject from such error output, and shortens the shutter speed to, for example, a maximum of 1/1000 seconds in accordance with the movement of the subject. Therefore, even if the object is moving at high speed, the image can be clearly photographed without blurring.

In this way, the electronic still camera device l! The motion detection circuit 12 detects the movement of the subject from the video signal obtained from the solid-state image sensor 3 which operates from the start of pressing the shutter button 3a, and adjusts the shutter speed of the solid-state image sensor 3 according to the detected movement of the subject. The shutter speed is automatically set for any subject, without the hassle of manually changing the shutter speed according to the subject's movement. Therefore, you can fully concentrate on tasks such as setting the angle of view and composition, and you can clearly record everything from high-speed subjects to stationary subjects.

In the above embodiment, the field memory 13 is used in the motion detection circuit 12, but a frame memory may be used instead of the field memory 13. Furthermore, it is also possible to adopt a configuration in which motion detection is not performed on the entire image, but only on the central part of the image. Furthermore, the video signal for one screen to be recorded on the magnetic disk 6 is not limited to one field, but can also be one frame.

Further, the magnetic disk 6 may be configured to be rotated at a constant speed before the shutter button 3a is pressed, in which case,
The motion detection circuit 12 detects the movement of the subject by pressing the shutter button 3a.
It can be detected even before you start pressing . Also,
If the solid-state image sensor 3 is being read out in the middle of a field when the shutter button 3a is pressed all the way, the motion detection circuit 12 will record on the magnetic disk 6 in time for the next field scan. , shutter button 3
It may operate even after pressing a completely.

[Effects of the Invention] As explained above, in the present invention, a motion detection circuit detects the motion of a subject from a video signal obtained from an image sensor that operates at or before the start of pressing the shutter button, and detects the motion of the detected subject. Since the shutter speed of the image sensor is varied according to the movement of the subject, and the optimal shutter speed is obtained according to the movement of the subject, there is no need to manually change the shutter speed according to the movement of the subject. Since the shutter speed can be switched between, you can fully concentrate on tasks such as setting the angle of view and composition, and it has excellent effects such as being able to clearly record both fast-moving and stationary subjects. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing an embodiment of an electronic still camera device according to the present invention, and FIG. 2 is a circuit diagram showing an example of a conventional electronic still camera device. 393. Solid-state image sensor, 3a, shutter button. 413. Video processing circuit, 6. ,,magnetic disk. 710. Shutter speed control circuit, 11. , ,Electronic still camera device, 12. ,,Motion detection circuit. 13., field memory, 14. , differential circuit, 15
．． ~15n,,, comparison circuit.

Claims (1)

[Claims] An electronic still camera device that records, on a rotating magnetic disk, a video signal for one screen obtained from an image sensor when a shutter button is fully pressed, the shutter speed being operated from the beginning of pressing the shutter button or before that. A variable image sensor, a motion detection circuit that detects movement of a subject by taking a time difference between video signals obtained from the image sensor until or after the shutter button is fully pressed, and a subject detected by the motion detection circuit. An electronic still camera device comprising: a shutter speed control circuit that varies the shutter speed of the solid-state image sensor according to the movement of the solid-state image sensor to obtain an optimum shutter speed.