Canon Kabushiki Kaisha

Minoru Takasaki

Yukihiro Matsumoto

Satoshi Suzuki

Akira Egawa

Takashi Ichimiya

Osamu Harada

Teruyuki Okado

Provided is a distance measurement and photometry apparatus used in a camera or the like, which sets a distance between distance measurement sensors and distance measurement light receiving lenses and a distance between a plurality of photometry sensors and photometry light receiving lenses such that a position of a region within the observation field in which information is obtained by the distance measurement sensors is equal to a position of a region within the observation field in which information is obtained by the photometry sensors irrespective of a distance to the measurement object. With this construction, it can be prevented that a distance measurement region in which the measurement object is captured and a photometry region provided corresponding to the distance measurement region are shifted with respect to each other even when the set measurement object is located at any distance.

Distance measurement and photometry apparatus

In a distance measuring apparatus which performs a distance measuring operation in an active mode and in a passive mode, time serially, on a basis of charging conditions determined for performing the distance measuring operation in one of the active mode or the passive mode, charging conditions to be used in the distance measuring operation in the other mode are determined.

Charging condition control in distance measuring mechanism

In a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light toward the object, in the case of an active distance measurement operation, the flickering frequency of a light beam projected from a light projection unit (B) toward the object (A) is prolonged within the range in which charges obtained by a signal charge supply unit (C) are not saturated in a circulating shift register (E). When the flickering period is longer than a predetermined period, a distance measurement operation inhibition unit (L) inhibits transition to a passive distance measurement operation.

Distance measuring apparatus

Disclosed is a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light onto an object, in which different reliability or contrast discrimination values are set in active and passive distance measurements. When the distance to the object is calculated by performing a correlation calculation on the basis of two received-light images obtained by an active or passive distance measurement, the reliability of the calculated distance and contrast values of the two received-light images are discriminated using the discrimination value.

When a voltage signal corresponding to charges circulating a circulating shift register including charge transfer channels, which are arranged in a ring pattern, are read out from the shift register as a signal value, since clocks for circulating the charges have a very high frequency, it is difficult to operate an A/D converter in synchronism with such clocks, and a very expensive A/D converter must be used. In view of this problem, when the signal is read out, the clock frequency is lowered, and the voltage signal corresponding to the charges is converted into a digital value using an A/D converter that operates at low speed. When a distance measuring device is configured using the circulating shift register, charges corresponding to an image are shifted by the circulating shift register. In this case, since the shift efficiency is less than 100%, the amount of charges immediately after a non-charge portion decreases as they are shifted, and such charges form a false image. In order to solve this problem, the distance is calculated without using any charges immediately after the non-charge portion.

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Yokohama, Japan

Minoru Takasaki