JPH03247083A - Electronic still camera - Google Patents

Abstract

PURPOSE:To utilize a power supply in a camera efficiently by inhibiting optical system movement by focal length adjustment means or drive of image pickup means when either one of them is executed. CONSTITUTION:When the focal length of a pickup optical system or a finder optical system is adjusted by a zoom button 40 and the drive of an image pickup element is started, the focal length adjustment is stopped. Moreover, when the zoom button 40 is depressed while the image pickup element 30 is driven, the drive of the image pickup element is stopped after the end of the recording and the movement of the optical system for the focal length adjustment is started if the picked-up video is being recorded, but, the drive of the image pickup element is immediately stopped and the movement of the optical system for the focal length adjustment is implemented if the picked-up video image is being not recorded. Thus it is not required to prepare an undesirably large capacity power supply.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic still camera, and more specifically to an electronic still camera that records captured images on a rotating recording medium.

[Prior Art] A still camera that records still images taken by a solid-state image sensor such as a CCD on a recording medium such as a magnetic disk;
A so-called electronic still camera has been proposed, and a configuration in which still images recorded on a magnetic disk are reproduced and displayed on a monitor device or printed on paper using a printer is also known.

Compared to conventional still cameras that use silver halide film, these electronic still cameras do not require chemical processing such as development, and images can be checked immediately on a monitor or hard copy. It also has the advantage of being able to be transmitted to remote locations.

[Problems to be Solved by the Invention] However, electronic still cameras consume a large amount of power to rotate a magnetic disk, which is a recording medium, and to drive an image sensor. Furthermore, if a focal length adjustment mechanism that electrically adjusts the focal length of the photographic optical system is incorporated, a large amount of power is consumed for the focal length adjustment.

In this way, when there are multiple circuits that consume a large amount of power during operation, it is theoretically possible to prepare a battery with a sufficiently large capacity, but in reality, there are limits to the battery capacity and the space in which the batteries can be accommodated.

Furthermore, if the driving of the image sensor and the above-mentioned focal length adjustment are performed at the same time, there is a problem in that the output video signal of the image sensor is disturbed due to a drop in the power supply voltage.

Therefore, an object of the present invention is to provide an electronic still camera that solves these problems.

[Means for Solving the Problems] An electronic still camera according to the present invention includes a photographing optical system with a variable focal length, an imaging means for converting an optical image by the photographing optical system into an electrical signal, and a photographic image to be taken. When one of the recording means for recording on a recording medium, the focal length adjustment means for adjusting the focal length of the photographing optical system, the driving of the imaging means, and the movement of the optical system for adjusting the focal length is performed, the other and control means for prohibiting. The second aspect of the present invention includes a control means for prohibiting the start of the focal length adjustment operation of the imaging means during the focal length adjustment for adjusting the focal point V giant tree.

[Function] The focal length adjustment operation of the photographing optical system that adjusts the focal length consumes a large amount of power at once, and temporarily lowers the power supply voltage. A drop in power supply voltage makes the operation of the imaging means unstable and causes disturbances in the output video signal. With the above means, the focal length adjustment operation and the driving of the imaging means are not performed simultaneously, and the imaging means always operates stably. Therefore,
A good video signal without any disturbance can be obtained from the imaging means. Furthermore, by not operating the imaging means and the focal length adjusting means at the same time, it is not necessary to prepare a power source with an unnecessarily large capacity.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram of an embodiment of the present invention. 10a is a focusing lens, 10b and 10C are focal length adjustment lenses, and 10d is a fixed lens, which constitute a photographing optical system. 12 is a focusing lens holding frame that holds the focusing lens 10a, and includes a gear portion 12a and a screw portion 1.
2b. 14.16 is focal length adjustment lens 1
0b.

This is a lens holding frame that holds 10c. A cam cylinder 18 is provided with a cam groove that determines the position of the lens holding frame 14, 16 in the optical axis direction, and is rotatably held in the fixed part 20 of the camera. 22.24 is the lens holding frame 14.16
It is a roller fixed to the cam tube 18, and passes through the cam groove of the cam tube 18.
The lens holding frame 14.16 is fitted into the long groove 20a in the optical axis direction of the camera fixing part to position the lens holding frame 14.16. Note that when the cam cylinder 18 rotates, the lens holding frame 1416 is held by the cam groove.
moves in the optical axis direction.

26 is an aperture, and 27 is a shutter. A finder optical system 28 includes lenses 28a and 28c fixed to the fixed part 20 of the camera, and a lens 28b movably held along the optical axis of the lenses 28a and 28c. 30
is an image sensor that converts an optical image into an electrical signal.

32 is a focusing motor that rotates the focusing lens frame 12, and the number of rotations thereof is detected by an encoder 32a. A gear 32b of the motor 32 meshes with a gear portion 12a of the focusing lens frame 12. Since the threaded portion 12b of the focusing lens holding frame 12 is engaged with the threaded portion 20b of the fixing portion 20 of the camera, the focusing lens holding frame 12 is moved in the optical axis direction by rotation of the motor 32.

34 is a zoom motor, the rotation speed of which is detected by an encoder 34a. A gear 34b of the motor 34 meshes with a gear portion 18a of the cam cylinder 18. When the zoom motor 34 rotates, the cam barrel 18 rotates around the optical axis of the photographing optical system by the gears 34b and 18a, and the focal length adjustment lenses 10b and 10c are moved to the lens holding frame 14 and 16 by the lift of the cam groove. and move in the optical axis direction.

36 is a finder motor, the rotational speed of which is detected by an encoder 36a. A screw 36b rotated by the motor 36 is engaged with a threaded portion 38a of a lens holding frame 38 that holds a movable lens 28b.
Due to the rotation of the lens holding frame 38, the movable lens 28
b is adapted to move in the optical axis direction.

40 is a zoom button, 42 is a photometry circuit, 44 is a distance measurement circuit, 46 is a recording circuit that records the photographed image on a recording medium, 48 is a camera control circuit that controls the whole, and 50 is a power source consisting of a battery. 52 is a display device (for example, a liquid crystal display device) that displays the operating status. As shown in FIG. 2, the camera control circuit 48 includes a so-called Nyatta control circuit, a focus control circuit, an aperture control circuit, a zoom control circuit, and an image sensor control circuit. In FIG. 2, 54a is a release button that is turned on when the shutter release button (not shown) is pushed in half a stroke.
The switch 54b is a release switch that is turned on when it is pushed further. Further, 40a is a zoom switch that instructs zooming to the telephoto side, and 40b is a zoom switch that instructs zooming to the wide side.

Next, the operation will be explained with reference to FIG. When a power switch (not shown) is operated to turn on the power, the camera control circuit 48 first opens the aperture 26, closes the shutter 27, and focuses the focusing lens 10a at infinity. Move it to the position you want to focus on (Sl). In this state, the photographer decides on the composition. That is, while looking through the finder, one of the switches 40a and 40b of the zoom button 40 is pressed. If the switch 40a is pressed (S2), the motors 34, 3
6 rotates forward, the photographing optical system and the finder optical system are adjusted to the telephoto side (S3), and when the switch 40b is pressed (S4
), the motors 34 and 36 are reversed, and the photographing optical system and finder optical system are adjusted to the wide side (S5).

After the composition is determined in this way, the photographer presses a release button (not shown). When the release switch 54a is turned on by pressing the release button half a stroke (S6), the camera control circuit 48 controls the photometry circuit 42.
The brightness of the subject is measured by the distance measuring circuit 44, the distance to the subject is measured by the distance measuring circuit 44, and the white balance is adjusted (
S7). After that, driving of the image sensor 30 is started (S8
). The aperture value and shutter speed are determined based on the photometry information, the amount of movement of the focusing lens 10a is determined based on the distance measurement information (S9), and the focusing lens 10a is moved to the determined position by the motor 32 (SIO).

After SIO, while the release switch 54a is on, it waits for the release switch to be pushed further and the release switch 54b to be turned on (S11.12). When the release switch 54a is turned off (S12), it means that no photography is to be done, so the focusing lens 10a is moved to a predetermined standby position (infinity focusing position) and the driving of the image sensor 3o is stopped. (313), return to S2. When the release switch 54b is turned on, a photographing operation is started. That is, the aperture 26 is driven to the aperture value determined in S9 (514), and the shutter 27 is opened for the determined shutter time (S15). The charges accumulated in the image sensor 30 are read out by opening and closing the shutter 27 and transferred to the recording circuit 46 (516), and the captured image is recorded in an unrecorded area of the rotating recording medium (517).

After this, if the release switch 54b remains on, photographing and recording (815-17) are repeated (S1
8). Even if the switch 54b is turned off, the switch 54b
If a remains on (S19), the focusing lens 10
A is stopped at that position, and the image sensor 30 is kept in a driven state, and waits for the switch 54b to be turned on (
S19). When the switch 54a is turned off, the aperture 26 is opened (520), the focusing lens 10a is moved to a predetermined standby position (infinity focusing position), the driving of the image sensor 30 is stopped (S13), and photography is started. end.

In this embodiment, the zoom button 40 (switch 40a,
If the driving of the image sensor 30 is started while the focal lengths of the photographing optical system and the finder optical system are being adjusted by step 40b), this focus adjustment operation is stopped. In addition, if the zoom button 40 is pressed while the image sensor 30 is being driven, and if the captured image is being recorded, after the recording is complete, the image sensor is stopped driving and the optical system for focal length adjustment is pressed. Movement starts, and if the photographed image is not being recorded, the driving of the image sensor is immediately stopped and the optical system is moved to adjust the focal length. Of course, during the shooting and recording operation, the image sensor 30
is driven.

It goes without saying that the recording medium for photographed images may be a solid-state memory such as a semiconductor memory.

In the above embodiments, a zoom lens whose focal length can be changed continuously is used, or even a lens that can select bifocal or multifocal, for example, is the same. Needless to say, the lens (group) that moves for focusing is not limited to the illustrated example. When a lens (group) for focal length adjustment (hereinafter referred to as a variable magnification lens group) is also used as a focusing lens, each group of this variable magnification lens group must be moved independently in the optical axis direction. It is necessary to be able to individually control the movement of Mechanisms for this are described, for example, in U.S. Pat.
8.951 etc.

[Effects of the Invention] As can be easily understood from the above explanation, according to the present invention, since the driving of the image sensor and the focal length adjustment of the photographing optical system are not performed at the same time, the power supply voltage fluctuation due to the focal length adjustment is reduced. There is no longer any negative effect on the operation of the image sensor,
Good video signals can be obtained. In addition, the power supply inside the camera can be used efficiently.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, FIG. 2 is a block diagram of the camera control circuit 48 of FIG. 1 and its peripheral circuit configuration, and FIG. 3 is a flowchart of the operation of FIG. 1. 10a: Focusing lens 10b, 10c: Focal length adjustment lens 10d: Fixed lens 12: Focusing lens holding frame 12a: Gear portion 12b = Threaded portion 14.16: Lens holding frame 18: Cam barrel 18a: Gear portion 20 : Camera fixing part 2Oa long groove part 20b: Threaded part 22,2
4: Roller 26: Aperture 27: Shutter 28: Finder optical system 28a, 28c: Lens 28b: Movable lens 30: Image sensor 32: Focus motor 32
a, 34a, 36a co-encoder 32b, 34b: Gear 34: Zoom motor 36; Finder motor 36b: Screw 38 Lens holding frame 38a: Screw part
40: Zoom button 40a, 40b: Zoom switch 54a, 54b Nirley's switch

Claims (3)

[Claims] (1) A photographing optical system with a variable focal length, an imaging means for converting an optical image taken by the photographing optical system into an electrical signal, a recording means for recording an image photographed by the imaging means on a recording medium, and a focal point of the photographing optical system. a focal length adjustment means for adjusting the distance;
An electronic still camera characterized by comprising: a control means for prohibiting the driving of the imaging means and the movement of the optical system by the focal length adjusting means when the other is being performed. (2) A photographing optical system with a variable focal length, an imaging means for converting an optical image by the photographing optical system into an electrical signal, a recording means for recording an image photographed by the imaging means on a recording medium, and a focal point of the photographing optical system. a focal length adjustment means for adjusting the distance;
An electronic still camera comprising: a control means for prohibiting the start of driving of the image pickup means while the focal length adjustment means is adjusting the focal length. (3) A photographing optical system with a variable focal length, an imaging means for converting an optical image by the photographing optical system into an electrical signal, a recording means for recording an image photographed by the imaging means on a recording medium, and a focal point of the photographing optical system. a focal length adjustment means for adjusting the distance;
An electronic still camera comprising: a control means for prohibiting the focal length adjustment means from starting a focal length adjustment operation while the imaging means is being driven.