Nikon Corporation

Shigeyuki Uchiyama

Yosuke Kusaka

Shozo Yamano

Tadao Takagi

Ken Utagawa

Chiyuki Kuwata

Masamitsu Ozawa

Shigemasa Sato

Hiroyuki Iwasaki

Tadao Kai

Toshimi Watanabe

Tsutomu Narisawa

Hideki Kanbayashi

Syozo Yamano

Toshihiro Sato

Masaru Muramatsu

Toru Fukuhara

Toshio Sosa

Yuji Katano

Daisuke Saya

Kenji Ishizuki

Isao Uchida

Kazuto Ohtsuka

Yoichi Koizumi

An image sensor includes: three or more photoelectric conversion devices; and a storage control circuit that controls storage operations at the photoelectric conversion devices, and the storage control circuit commonly controls the storage operations at two or more photoelectric conversion devices that are not disposed directly next to one another among the photoelectric conversion devices.

Image sensor, focal point detection device and camera

A sub-mirror which deflects a focal point detection light flux passing through an area off the optical axis of a photographing optical system toward the optical axis and a second deflection member that deflects the focal point detection light flux deflected by the sub-mirror to allow it to advance roughly parallel to the photographic optical axis are provided. A pair of light fluxes achieved by deflecting the focal point detection light flux twice are guided to an image sensor to form a pair of subject images on the image sensor. The focal adjustment state is detected based upon the extent to which the pair of subject images are offset.

Focal point detection apparatus and focal point detection module

A focal point detection apparatus that includes a sub-mirror constituted of a concave mirror and performs focal point detection in the phase difference detection method is capable of implementing a focal point detection over a wide range. A light flux for focal point detection having passed through a semi-transmissive reflecting member and a reflecting member constituted of the concave mirror described above enters a focal point detection optical system. A correction optical system provided between the semi-transmissive reflecting member and the reflecting member constituted of the concave mirror corrects an offset of the direction along which the light flux for focal point detection advances caused by the reflecting member constituted of the concave mirror, in conformance to the image height at the focal point detection position. By utilizing this correction optical system, it becomes possible to reduce the size of the focal point detection apparatus while assuring a large focal point detection area.

Camera and focal point detection apparatus

The area in which focus detection is performed is selected from among a plurality of focus detection areas provided on a photography screen. In the pair of photoelectric converters corresponding to the selected focus detection area, charge accumulation is repeatedly performed based on at least one of the image signals from the pair of image signals output from this pair of photoelectric converters. The focus adjustment condition of the photograph optical system is computed based on this pair of image signals. In the pair of photoelectric converters corresponding to the non-selected focus detection areas, charge accumulation is repeatedly performed over a period longer than the period of charge accumulation in the pair of photoelectric converters corresponding to the selected focus detection area based on at least one of the image signals from the pair of image signals output from this pair of photoelectric converters. The structure and method improve the responsiveness of focus detection when the focus detection area is changed without causing the responsiveness of normal focus detection to decline.

Focus detection device and focus detection method

The invention eliminates field mask eclipse related to a focal detection apparatus that uses a phase variation detection method, and provides an adjustment device and method for the focal detection apparatus. The focal detection apparatus includes a field mask; a separator optical system that divides and forms a set of light images of a beam of light transmitted through the field mask; an image sensor that photoelectrically converts light images from the separator optical system; a light-receiving area memory device; a masking device that masks the photoelectric output of the image sensor according to the light-receiving areas written into the light-receiving area memory device; and a focal computation device that computes a defocusing amount from the photoelectric output masked by the masking device. The adjustment device and method writes into the light-receiving area memory device the light-receiving areas not incurring optical eclipse when uniform illumination is projected onto the image sensor via the field mask and the separator optical system.

Focal detection and adjutment device and method

A camera includes a photo-taking lens, an automatic focus adjusting device for effecting the automatic focus adjustment of the photo-taking lens, an eye-gaze detecting device for detecting the photographer's eye-gaze position in a finder field corresponding to a photographing picture plane, and producing an eye-gaze detection signal corresponding to the eye-gaze position, a focus adjustment signal producing device for outputting a plurality of focus adjustment signals corresponding to a plurality of detection areas in the photographing picture plane, and a control signal producing device for producing a control signal for controlling the automatic focus adjusting means, on the basis of the eye-gaze detection signal and the focus adjustment signals. The control signal producing device produces the control signal on the basis of the plurality of focus adjustment signals corresponding to the plurality of detection areas when the eye-gaze position indicated by the eye-gaze detection signal is at a position between the plurality of detection areas.

Camera capable of detecting eye-gaze

A focus detection device to improve the level of confidence of focus detection results of an object image by determining the defocus amount based on the filter processing data computed by a filter processing circuit for high frequencies of the subject image is disclosed. Computations may be repeated related to successively lower frequencies until a high level of confidence of the computed defocus amount is achieved.

Focus detection device

An optimum focus detection algorithm range is established in the focus detection area corresponding to the subject pattern. The method includes establishing a first region on the photoelectric conversion array; computing the contrast of the subject image in the first region based on the output signal strings of a plurality of photoelectric conversion elements contained in the first region; establishing a portion of the first region as a second region; and computing the contrast of the subject image in the second region based on the output signal strings of a plurality of photoelectric conversion elements contained in the second region. Subsequently, either the first region or the second region must be determined as the focus detection algorithm range based on the contrast of the first region and the contrast of second region. The focus adjustment condition of the shooting lens is computed based on the output signal strings of the first region or the second region, whichever is selected as the algorithm range.

Focus detection device and method

A focus detection device includes a pair of photoelectric converting element arrays that output a pair of signal strings and a focus detection optical system, including a photo lens, that conducts a pair of light rays from a subject to the pair of photoelectric converting element arrays. A filter extracts a pair of signal strings having a predetermined frequency component from the pair of signal strings outputted by the photoelectric converting element arrays. A calculation range setting device sets a calculation range of signals of the pair of extracted signal strings, and a focus detection calculating device calculates a focus adjustment condition for the photo lens based on the signals of the pair of extracted signal strings in the calculation range. A contrast calculation device calculates the contrasts in areas outside the calculation range based on the signals of the pair of extracted signal strings excluded from the calculation range, wherein the operation of the focus detection calculating device is dependent upon the calculated contrasts. When the calculated contrast exceeds a predetermined value, focus detection calculations based on a pair of signal strings with lower frequency components are not carried out, or else the shift range for correlation calculations is narrowed, or else the threshold values for reliability determination are changed and the reliability determination standard is made to be more restrictive, or else the focus detection calculation range is narrowed.

A focus state detection device accurately detects in a short period of time the defocus amount of an arbitrary subject even when a plurality of subjects having different photographic distances are intermixed within the focus state detection region. Normally, the defocus amount is calculated on the basis of electric signal strings from each of a plurality of blocks. However, if one of the blocks is a perspective conflict block in which are intermixed a plurality of subjects having different photographic distances, new blocks are established containing at least part of the perspective conflict block. The defocus amount is calculated on the basis of the electric signal strings corresponding to these new blocks.

Focus state detection device and method

A defocus amount is accurately determined within the photo field. As applied to a focus state detection device, DC reduction filter process data is computed without completely extracting the DC component of the signal string output from an image sensor. The DC reduction filter process data is divided into three regions, and a determination is made as to whether focus state detection is possible for each region. When the determination is negative, a determination is made as to whether focus state detection is possible for all regions of first filter process data that extracts high frequency components. When the determination is negative, a determination is made in a similar manner as to whether focus state detection is possible on the basis of second filter process data and third filter process data. When the determination has been made that focus state detection is possible for all regions with one of the filter process data, a standard block is set, a weighing coefficient is set for each block on the basis of this standard block, the defocus amount of each block is altered, the defocus amounts are combined, and a final defocus amount is determined.

A focus adjustment device that eliminates unnecessary driving of a shooting lens after the shooting lens has already been driven near to an in-focus position. In a focus adjustment device, information related to the defocus amount of the shooting lens is detected based on output signals corresponding to the light intensity distribution of a object image from a pair of photo-electric conversion arrays. The focus adjustment device includes a focus detection circuit to determine the confidence level of the detected information based on predetermined determination criteria and a lens driving device to drive the shooting lens based on the detected information when the information of the focus detection device is accepted as having a sufficient confidence level. However, to prevent erroneous driving of the lens, such as when the object moves out of a focusing field or when the object reverses direction, the probability of rejecting the information of the focus detection on the basis of an insufficient confidence level increases. This occurs when information indicating that the occurrence of a defocus amount exceeding a predetermined range is detected by the focus detection circuit after the shooting lens has previously been determined to have been driven within permissible parameters of an in-focus position.

Focus adjustment device and method

A focus detection device is disclosed that establishes a focus detection algorithm range on photoelectric conversion element arrays and detects the contrast distribution of the output signal strings of the arrays corresponding to this algorithm range. Moreover, the focus detection device determines transformation coefficients for the algorithm range based on a detected contrast distribution and coefficients predefined for some of a plurality of photo-electric conversion elements of the photo-electric conversion element arrays. The focus detection device computes the relative shift amount of the output signal strings corresponding to the algorithm range, and converts the shift amount into a defocus amount of a shooting lens based on the determined transfer coefficients. Moreover, while relatively shifting the pair of output signal strings of the pair of photo-electric conversion element arrays by a specific amount within the predetermined shift range, the invention computes a correlation-amount at each shift position and detects the focus adjustment condition of the shooting lens based on the shift position yielding the minimum correlation amount. The detected focus adjustment condition is determined to have a high level of confidence if the amount of change in the correlation amount in the vicinity of the shift position yielding the relatively minimum correlation amount satisifies specified conditions.

Growing community of inventors

Tokyo, Japan

Shigeyuki Uchiyama