Tokyo Shibaura Denki Kabushiki Kaisha

Nippon Kogaku K.k.

Nobuaki Yoshida

Kazushige Ooi

Yoshio Mori

Shigekazu Fujiwara

Tsuneo Sukegawa

Sumio Sakai

An image pickup apparatus such as a video camera including a pickup tube, a diaphragm mechanism and an electrochromic filter plate which are disposed along the optical path of incident image light on the pickup tube. When an illuminance of an object to be photographed is lower than a predetermined illuminance, only the diaphragm mechanism is used to suitably control an exposure of the pickup tube. However, when the illuminance of the object exceeds the predetermined illuminance level, the diaphragm mechanism is operated to keep its aperture size at a predetermined aperture size which is larger than an original minimum aperture size corresponding to a pinhole state. At the same time, the electrochromic filter plate continuously changes its light transmissivity in response to an aperture control signal, thereby controlling the exposure of the pickup tube.

Image pickup apparatus

The invention provides a color image pickup device in which image light from a white object to be photographed or image light integrated by a diffusion plate or the like is incident on a pickup tube through an electrochromic element. Two primary color signals are separated from a video signal from the pickup tube, a voltage corresponding to a difference between the two primary color signals is detected by a differential amplifier, and the voltage is then applied across an electrochromic element. A spectral transmittance of which is then controlled, thereby achieving an optimal white balance.

Color image pickup device

A television camera equipped with an active filter section capable of producing dynamic special effects in the picture. The filter section of the camera includes an electro-optic light control device which is arranged in the optical path of the imaging optical section of the television camera such that its light transmittance for the incident light to the image screen of the camera is varied in response to the application of an electric signal, and the variable transmittance area is divided into a plurality of sections adapted to be controlled and drived selectively. Also, the camera includes a drive unit for selectively controlling and driving the sections of the electro-optic light control device so as to vary with time the spread of the area of the sections having the transmittance varied in response to the application of the electric signal.

Growing community of inventors

Tokyo, Japan

Nobuaki Yoshida