Sony Corporation

Joichi Sato

Toshiaki Isogawa

Mitsuru Sato

Ryuji Shiono

Tsutomu Niimura

Shuji Shimizu

Tsutomu Nimura

A video camera includes a solid state image pickup element for converting a light image radiated thereon from an object to be photographed into an electric signal. The element is also operated as a shutter for controlling an amount of light radiated thereon by being controlled in its storage time. The video camera further includes a unit for inputting data for setting a storage time of the image pickup element, and a unit connected to the data inputting unit for controlling the storage time of the element in response to the inputted set data gradually to the set data by changing the storage time by a predetermined storage time for the lapse of every predetermined time period.

Video camera

A video signal inverting circuit, wherein a pedestal level of an output signal is selectively changed between a posi-mode and a nega-mode. The pedestal level of the output video signal is set equal to the pedestal level of the posi-mode output video signal in the nega-mode in accordance with a nega-mode/posi-mode control signal. In spite of the nega-mode/posi-mode control signal, a level setting circuit for the posi-mode is used during horizontal blanking period in the nega-mode.

Video signal inverting circuit

A circuit for controlling the gain of an amplifier typically used in a video camera has a automatic gain control circuit to provide the camera output signal within predetermined limits and a switch to permit exclusion of the automatic gain control feature and the use of a manually variable gain control having a greater range and overlapping that of the automatic gain control to provide further flexibility to the user of the camera so that objects normally too bright or too dark to be accommodated within the range of the automatic gain control circuit can be recorded. Differential amplifiers operating in conjunction with current mirror circuits are provided in both the variable gain amplifier circuit and in the circuit that provides the gain control signal thereto to provide a gain control circuit that lends itself to integrated circuit fabrication.

Video camera gain control circuit

A circuit having a nonlinear response characteristic provides gamma compensation to a video luminance signal and matches any desired output response curve by selecting the number of diodes connected as series-connected circuits in the compensation circuit. The relationship among the various numbers of series-connected diodes is dependent upon having a current flowing into an output circuit which is the same as a current flowing out of a collector circuit of a differential amplifier, to which the input video luminance signal is applied, and through series-connected diode circuit. These currents are maintained equal by use of a current-mirror circuit, which provides an input current to an output transistor that has in its emitter circuit one of the series-connected diode circuits, and the compensated luminance signal flows in the collector circuit thereof. The differential amplifier is stabilized and balanced by a difference amplifier connected in feedback across the collector leads of the differential amplifier in conjunction with a pedestal clamping synchronization signal and a capacitor to provide a balancing signal at the base lead of the second transistor of the differential transistor amplifier.

Growing community of inventors

Atsugi, Japan

Joichi Sato