Asahi Kogaku Kogyo Kabushiki Kaisha

Fuji Photo Film Company, Limited

Asahi Kogaku Kogyo K.k.

Fujifilm Corporation

Asahi Kogaku Kabushiki Kaisha

Shigeo Toji

Noboru Suzuki

Masahiro Kawasaki

Osamu Shindo

Yukio Uenaka

Atsushi Misawa

Hiroshi Endo

Saburo Sugawara

Kentaro Tokiwa

Ryota Ogawa

Akihiro Arai

Masaaki Takagi

Yasuyuki Tejima

Masanori Yoshida

Kazushi Yoshida

Koji Kobayashi

Zenichi Okura

Hiroshi Shimaya

Hideaki Yuda

Masaki Kohama

A digital still camera includes a lens system and an image sensor. The image sensor receives object light through the lens system to output an image signal of an object, wherein exposure control and autofocus control of the lens system are carried out according to the image signal. The image sensor photographs an image of the object after the exposure control and the autofocus control. Auxiliary light is applied to the object with an illumination light source for the autofocus control. A second exposure value is determined by use of a first exposure value determined according to object brightness measured while the illumination light source is inactive. Exposure is carried out to measure object brightness by use of the second exposure value while the auxiliary light is applied, for determining a third exposure value for use in the autofocus control with the auxiliary light.

Image pickup apparatus and exposure control method

A digital camera system is composed of a digital camera and a lens unit detachable to this digital camera. The digital camera includes a first taking lens and a first CCD image sensor to convert subject light into image data. The first taking lens is surrounded by a detachable decorative ring. When a hook release button is pressed to detach the decorative ring, a camera-side mount appears. The lens unit is attached to this camera-side mount, and photographing can be performed with a second taking lens and a second CCD image sensor in the lens unit.

Digital camera, digital camera system, and control program for digital camera system

A face detector detects a person's face from a through image. When the face is not found, and a shutter button is pressed fully, a correction lens is moved in the direction and at the speed to offset a camera shake detected by an angular velocity sensor and a still image is shot. When the face is found, and the shutter button is pressed halfway, a motion vector detector reads two through images from a SDRAM to detect a subject shake. During the shooting of the still image by full press of the shutter button, the correction lens moves in the direction and at the speed to offset the subject shake.

Imaging device and imaging method

A digital still camera includes an aperture stop opening, a taking lens system, and a CCD pickup element. In a manual focus device, an iris shifting mechanism sets the aperture stop opening in an aperture stop unit with reference to a first light amount gravity center by shifting the aperture stop opening to the right relative to a lens optical axis, and sets the aperture stop opening with reference to a second light amount gravity center by shifting the aperture stop opening to the left. First and second sample pickup data are obtained by the CCD pickup element in the setting of the aperture stop opening at the two light amount gravity centers. A display panel displays first and second sample images according to the sample pickup data, to indicate a present deviation of the taking lens system from an in-focus position in simulation. A focusing ring is externally operable, for moving the taking lens system on the optical axis, and for actuation while the two sample images are checked visually, to position the taking lens system when the two sample images inform a reach to the in-focus position.

Manual focus device and autofocus camera

For an image to be displayed on a liquid crystal display, a thinning process is executed to reduce a number of pixels constructing the image. An original image of an information image is produced in accordance with a pixel number of a taken subject image. A low-pass-filter process is executed for the original image. After the low-pass-filter process, the processed original image is written in a data ROM as the information image. When a digital camera is operated, the information image is displayed on a screen of the liquid crystal display by using the data of the information image stored in the data ROM.

Method for displaying an information image on a screen

An image magnification control device for a camera having a photographic lens. A distance 'X0' between a rear focal point of said photographic lens and an image taking plane of the camera is detected. Additionally, a defocusing amount 'dx' corresponding to a distance between the image taking plane and a surface on which an image is formed by the photographic lens is detected. A magnification ratio .gamma. of a control focal length 'f1' required to maintain an image magnification to a present focal length 'f0', that is based on the distance 'X0' and the defocus amount 'dx' is then calculated in accordance with a predetermined equation. Thereafter, an amount to drive the photographic lens to maintain the image magnification, based on the magnification ratio .gamma. is calculated, and the photographic lens is driven to change a focal length of the photographic lens.

Image magnification control device for a camera

An image magnification control device for a camera. Control focal length required to maintain an image magnification constant is computed based upon defocus information detected by analyzing a light that passes through a photographic lens. In case a focal length of the photographic lens moves out of a range wherein the set image magnification can be obtained, various options, such as a shutter-release lock operation, can be executed depending upon the chosen design of the camera.

An image magnification control device for a camera having a photographic lens. The image magnification control device includes a first detector that functions to detect a focal length 'f0' of the photographic lens. A distance 'X0' between a rear focal point of the photographic lens and an image taking plane of the camera is then determined based on a delivery-amount of a focusing lens of the photographic lens and the detected focal length 'f0'. A second detector detects a defocusing amount 'dx' by analyzing a light passed through the photographic lens, in which the defocusing amount 'dx' represents a displacement of an image formed by the photographic lens from the image taking plane. An image magnification 'm0' is determined based on a formula 'm0=X0/f0', while a control focal length 'f1' is calculated based on a formula 'f1=(f).sup.2 .multidot.m0)/(X0+dx)'. The focal length of the photographic lens is thus controlled so as to meet the control focal length 'f1'.

A zoom optical system (25) is associated with an image sensor (46), which is disposed behind the zoom optical system for picking up an object (6). The zoom optical system is focussed by use of a photoelectric signal from the image sensor. In a setup mode, the zoom optical system is zoomed from a first magnification to a preset magnification. The zoom optical system has been set at the first magnification. The preset magnification is adapted to focussing. The zoom optical system is focussed in accordance with the photoelectric signal generated while the zoom optical system has the preset magnification. The zoom optical system is zoomed back from the preset magnification to the first magnification, while keeping the zoom optical system in-focus. The zoom optical system becomes in-focus at the first magnification in a manner in which the zoom optical system is in-focus at the preset magnification.

Auto focussing method and device

An image magnification control device for a camera having a photographic lens. A defocus amount 'dx' of an object is detected by analyzing a light that passed through the photographic lens. A control focal length 'f1' required to maintain an image magnification is calculated that is based upon the detected defocus amount 'dx'. Thereafter, it is determined whether the control focal length 'f1' falls within a range between a tele terminus focal length 'ft' of the photographic lens and a wide terminus focal length 'fw' of the photographic lens. A first controller controls a focal length of the photographic lens so as to meet the control focal length 'f1' when it is determined that the control focal length falls within the range, while a second controller controls the focal length of the photographic lens so as to meet one of the tele terminus focal length 'ft' and the wide terminus focal length 'fw' when it is determined that the control focal length 'f1' goes beyond the range.

A lens focusing system for a camera. The camera includes a focusing lens that is movable between a first terminus point and a second terminus point. An amount required to move the focusing lens to obtain an in-focus condition is determined, which is used to drive the focusing lens to position the focusing lens at the in-focus condition. A plurality of drive signals are generated in response to the driving of the focusing lens, which are monitored. A monitored position value is established that is based upon the plurality of drive signals monitored by the monitoring means, and the monitored position value is compared with a predetermined position value corresponding to one of the first terminus point and the second terminus point after the lens has been moved by the amount determined to be required to move the focusing lens to obtain the in-focus condition. The focusing lens is then driven in a direction until the focusing lens is prevented from moving when the monitored position value corresponds to a position which is out of a range between the first terminus point and the second terminus point. When the focusing lens has been moved to one of the first terminus point and the second terminus point, the monitored position value is replaced with the predetermined position value.

A zone for measuring distance is enlarged by adding an area where a contrast ratio is relatively high in the case of the photographing against the light. Thus, the sensitivity for judging a contrast ratio is increased and improper focusing is prevented. The brightness when an evaluative value is a maximum and the brightness at a moment when the evaluative value is not at maximum, for example when it is at a minimum, are compared. If the difference of brightness becomes too large, the maximum evaluative value is ignored and the detection is repeated. The determination of when the difference in brightness is too large is made to be dependent on parameters such as gain of the AGC circuit, gain of the amplifier and iris opening which affect the noise in the evaluative value so as to more accurately judge when the when the maximum evaluative value should be ignored.

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Tokyo, Japan

Shigeo Toji