Mitsubishi Denki Kabushiki Kaisha

Norio Ookawa

Susumu Takahashi

Masashi Ueno

Osamu Kaneta

An infrared camera includes a temperature sensor () and an element operating temperature setting circuit () for setting a temperature obtained by adding a desired offset to the temperature of the temperature sensor () immediately after the power-on as an operating temperature of an imaging device (), and images with the imaging device () settled to the temperature obtained by adding the desired offset to the temperature of the temperature sensor () immediately after the power-on.

Infrared camera

An infrared camera with lower dissipation power, a wide range of operating environment temperature, and a shorter warmup is provided. The infrared camera includes a plurality of device operating-temperature setting circuits setting respective device operating temperatures different from one another, a device operating-temperature setting switch for selecting one of the output of the device operating-temperature setting circuits, and a temperature sensor, and performs imaging by switching the connection target of the device operating-temperature setting switch according to a measurement by the temperature sensor, that is to say, according to the temperature inside an enclosure and selecting an operating temperature for an imaging device among a plurality of device operating-temperature settings.

Infrared camera and infrared camera system having temperature selecting switch

An infrared camera capable of automatically executing offset compensation so that fixed pattern noise is removed without the need of an operator comprises an offset compensation signal generation circuit and a shutter. The shutter is closed based on an offset compensation execution signal for carrying out offset compensation, the signal being automatically and periodically generated by the offset compensation signal generation circuit after execution of the first offset compensation.

Circuitry for a bolometer-type image pickup device improves the signal-to-noise ratio and reduces variations of an output offset level due to temperature variations of the device. A clamp voltage is applied to an amplifier 18 via a clamping diode 36 connected thereto. This reduces a difference between an input voltage during an off-state of one of horizontal FET switches 9, 10, and an input voltage during the off-state of both horizontal FET switches 9, 10, thereby improving a signal-to-noise ratio by narrowing a frequency band of an external circuit. Further, a variable load resistor 43 whose resistance varies with temperature similarly to those of bolometers 1-4, a resistance of a pseudo resistor 44 which is substantially equal to a sum of conductive resistances of vertical FET switches 1, 14 and horizontal FET switches 9, 10, and a compensating diode 45 whose forward bias voltage varies with temperature similarly to those of pixel separating diodes 39-42 are connected in series between the horizontal FET switches 9, 10 and a bias current output terminal 12, thereby offsetting variations of an output offset level due to temperature variations.

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Tokyo, Japan

Norio Ookawa