Ricoh Company, Ltd.

Daisuke Hata

Yoshimi Ohno

Takayuki Hatase

Kazumasa Aoki

Susumu Iguchi

Takao Yamaguchi

Kenji Koyama

Kousaku Sawabe

The autofocus apparatus determines a focus position according to a result of sampling an AF evaluated value and drives a lens system to the focus position. This autofocus apparatus further performs a flash in synchronism with a sampling timing of an AF evaluated value.

Autofocus apparatus having a flash synchronized to an autofocus sampling time

In the auto-focus apparatus, a CPU controls an amount of shift of a focus lens system for each sampling when an AF evaluated value is sampled so that the amount of shift is changed according to a number of recording pixels in a CCD. Therefore, even if a CCD having a large number of pixels is utilized the apparatus can perform auto-focusing within a short time.

Auto-focus apparatus based on pixel resolution and control method for the same

A CPU measures a cycle of a vertical synchronization signal inputted from an IPP based on an oscillation frequency of an internal ceramic oscillator. The CPU corrects the timing of starting the control of an object to be controlled based on the measured cycle of the vertical synchronization signal when the timing of starting the control of the object to be controlled is to be decided based on the vertical synchronization signal as a reference.

Digital camera and control method for the same

The autofocus apparatus determines a focus position according to a result of sampling an AF evaluated value and drives a lens system to the focus position. This autofocus apparatus further performs a flash in synchronism with a sampling timing of an AF evaluated value, and the light quantity of each flash is maintained substantially constant.

Autofocus apparatus

A method, system and computer readable medium for an automatic focusing device including an optical system including receiving a light flux from an object to be photographed, the received light flux being passed through an optical system having a focusing lens system to form an image of the object and converting the received light flux into an output image signal; converting the image signal to output digital image data; outputting luminance data according to the digital image data as an automatic exposure (AE) evaluation value; setting at least an area of an imaging screen of an imaging device as an automatic focusing (AF) area; determining if the AE evaluation value is smaller than a predetermined value and setting an enlarged AF area as the AF area when the AE evaluation value is smaller than the predetermined value; integrating high frequency components of luminance data of image data in the AF area and outputting resulting data as an AF evaluation value; sampling AF evaluation values while moving the focusing lens system; and determining if the device is in focus based upon a result of the sampled AF evaluation values and driving the focusing lens system to a focusing position when the device is not in focus.

Method, system, and computer readable medium for controlling automatic focusing of a digital camera

A method, system and computer readable medium for controlling a digital camera including setting a shutter speed; receiving a light flux from an object to be photographed to form an image thereof at the set shutter speed; converting the received light flux into an image signal; amplifying the image signal with a variable gain; judging whether or not the shutter speed is set slower than a predetermined blur avoiding speed; and increasing the variable gain to a predetermined value when the shutter speed is set slower than the predetermined blur avoiding speed. Another embodiment includes a method, system and computer readable medium for controlling a digital camera including setting a shutter speed; receiving a light flux from an object to be photographed to form an image thereof at the set shutter speed; converting the received light flux into an image signal; amplifying the image signal with a variable gain; judging whether or not the shutter speed is set slower than a predetermined blur avoiding speed; selectively setting a photographing mode to one of: a blur avoiding photographing mode in which the variable gain is increased to a predetermined value when the shutter speed is set slower than the predetermined blur avoiding speed, and a normal photographing mode in which the variable gain is not increased even when the shutter speed is set slower than the predetermined blur avoiding speed; and increasing the variable gain to a predetermined value when the blur avoiding photographing mode is set and when the shutter speed is set slower than the predetermined blur avoiding speed.

Method, system, and computer readable medium for controlling a digital camera to avoid blurring of a photograph

The autofocus apparatus has a first mode of shifting a focus lens at a fine step interval so as to sample an AF evaluation value, and for detecting an in-focus position on the basis of a sampling AF evaluation value; and a second mode of shifting the focus lens at a coarse step interval so as to sample an AF evaluation value, and detecting a rough in-focus position on the basis of the sampling AF evaluation value, and subsequently, shifting the focus lens at a fine step interval so as to sample an AF evaluation value in the vicinity of the rough in-focus position, and detecting an in-focus position on the basis of the sampling AF evaluation value, and further, can select the first mode and the second mode.

In a digital camera, a gain for a variable gain amplifier is controlled by a controller so that when a signal level of an image signal for a CCD is corrected by the variable gain amplifier, a quantization error or an exposure error generated when a shutter speed is set by a unit of CCD electric charge sweep-away pulse will be offset.

Digital camera with variable gain to offset exposure error

A pulse-controlled camera has a single motor capable of conducting a drive of a photo-taking lens and a drive of opening and closing of shutter blades at a high speed with a high reliability and a high precision in a compact structure, in which mechanical errors in machining and assembling may be electrically adjusted and which can facilitate automatic assembling. The pulse-controlled camera comprises a basic reciprocating member which is rotated in a forward direction or in a backward direction with respect to a home position by a pulse motor. The forward rotation of the basic, reciprocating member from the home position also rotates a lens feeding member through a ratchet base plate in the forward direction, so that a cam action of the lens feeding member feeds a lens holding frame up o a position corresponding to a measured distance value. Then the basic reciprocating member rotates in the backward direction while leaving the ratchet plate at the position, passes the home position, and rotates a shutter blade opening and closing lever by an engaging pin thereof to open the shutter blades. The home position of the basic reciprocating member is set based on a timing when a home position signal generating portion interrupts a beam for detection of a photo interrupter.

Pulse-controlled camera, method for setting control reference position

A control system for vari-focal lens can keep a vari-focal lens in focus during magnification change, and can conduct quick focusing even if a distance measurement is not possible in a phase difference detection method. A focusing correction calculation circuit calculates two data, one of which is a focusing lens position datum obtained by a focusing lens position detection device and the other of which is a magnification changing lens group position datum obtained by a magnification changing lens position detection device, to obtain a correction amount datum and a correction focusing direction datum. Another calculation circuit obtains a phase difference datum based on a phase difference detection datum detected by a phase difference detector. If a judgement circuit judges either that the distance measurement is not possible, that the phase difference is under calculation, or that the phase difference is under detection, a focusing correction is effected based on the correction amount datum and the correction focusing direction datum. If the judgement circuit judges otherwise, the focusing is effected based on the datum obtained from the phase difference detection datum.

Vari-focal lens control system with lens driving and magnification lens

A lens controller comprises a focusing device for driving a focusing lens group; a zooming device for driving a zoom lens group; a focusing position detector for detecting the position of the focusing lens group on an optical axis; a zoom position detector for detecting the position of the zoom lens group on the optical axis corresponding to a focal distance thereof; a calculating device for respectively receiving outputs of the zoom and focusing position detectors and calculating a correction amount with respect to a shift in position of a formed image after the zoom lens group is driven by the zooming device; a control device for receiving the correction amount and controlling the operation of the focusing device such that the focusing lens group is moved to a focusing position with respect to the focal distance thereof; a device for judging whether or not the focusing lens group is located in inhibit regions on infinite and proximate sides respectively formed within a predetermined distance in a direction from an infinite position to a proximate position and in a direction from the proximate position to the infinite position; and a device for receiving an output of the judging device and inhibiting the focusing lens group from being moved in the directions toward the infinite and proximate positions when the focusing lens group is respectively located in the inhibit regions on the infinite and proximate sides.

Focusing device for driving focusing lens group according to a position

Lens controller

A lens controller comprises a varifocal lens changed by a focusing position with respect to a shifting amount of an image forming position; a focusing drive unit for driving a focusing lens group constituting a zooming optical system; a zooming drive unit for driving a zooming lens group constituting the zooming optical system; a detector for detecting the position of the focusing lens group between proximate and infinite positions; a detector for detecting the position of the zooming lens group on the optical axis thereof corresponding to the focal distance of the entire zooming optical system; a focusing correction control device for calculating a correcting amount of the shift of the image forming position with respect to the focal distance when the zooming operation is performed to change the focal distance of the entire zooming optical system by the zooming drive unit, the focusing correction control device controlling the focusing drive unit so as to move the focusing lens group to the focusing position in accordance with the correcting amount; and a zooming speed control device for receiving an output of the focusing lens group position detector and changing the zooming speed in a predetermined relation based on the change in output of the focusing lens group position detector. The other constructional devices may be used to automatically correct the shift of the image forming position.

Lens controller includes a zooming optical system and a zooming speed

A position detecting apparatus electrically detects the present position of a moving body reciprocated within a movable region. The apparatus comprises a resistance section continuously disposed by a predetermined length along the reciprocating direction within a detecting region corresponding to the movable region on a substrate composed of an insulator. A plurality of region discriminating patterns are formed by combining a conductive section discontinuously disposed by a predetermined length along the reciprocating direction within the detecting region on the substrate, and an insulating section having no conductor. An electric brush is provided which is connected to the moving body and reciprocated within the detecting region in a state in which the brush slidably contacts the resistance section and the plurality of region discriminating pattern section. A first position detector detects the position of the moving body based on a resistance value corresponding to the position of the brush when the brush is located on the resistance section. A second position detector detects the position of the moving body by detecting a predetermined kind of combination of the conductive section and the insulating section when the brush is located on the region discriminating pattern sections; both the resistance section and the region discriminating pattern sections are disposed on the substrate. Another position detecting apparatus may be used by electrically detecting the present position of the moving body reciprocated within the movable region.

Position detecting potentiometer for a moving body

A zooming optical system control device for controlling the setting of a zooming optical system to one of a plurality of regions such as a zooming region wherein the optical system ensures zooming photographing, a macro region wherein the optical system ensures macro photographing and a containment region wherein the optical system is contained into a predetermined position, the optical system having a zooming lens group, a macro lens group and a focusing lens group each disposed on one identical optical axis.

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Saitama, Japan

Daisuke Hata