Abstract: An infrared detecting arrangement includes an infrared detecting element having a heat insulating film and an infrared detector which are disposed between an interior space of a hermetically sealed casing for the element and a cavity formed within a substrate of the element and communicating through a ventilator with the interior space.

Abstract: A semiconductor device includes laminated photoelectric conversion elements each having a semiconductor thin film carrying out the photoelectric conversion, the respective semiconductor thin film having a relationship L.ltoreq.1/.alpha.(.lambda.) when incident light is of a wavelength .lambda., the semiconductor thin film is of an absorbtion coefficient .alpha.(.lambda.) with respect to the light of the wavelength .lambda. and the carrier collecting length is L, whereby the optimum combination of the incident light wavelength and the sensitivity of the device can be obtained to realize a high photoelectric conversion efficiency.

Abstract: An optical control circuit is formed by a first transistor, a first resistive element connected between control electrode and first output electrode of the first transistor. The first output electrode forms an emitter or source of the transistor, a second resistive element is connected between the control electrode and second output electrode of the first transistor. The second output electrode forms a collector or drain of the transistor and an array of photovoltaic elements is connected in parallel to the second resistive element. A second transistor has a control electrode connected to the second output electrode of the first transistor. High speed operation of the second transistor can be assured, any noise voltage applied to the control electrode of the second transistor can be effectively bypassed, and the first transistor can be simultaneously formed in a substrate of the second transistor to be integralized therewith.

Abstract: An optical control circuit is formed by connecting a photoconductive element and resistive element at their one end to the control electrode of a transistor, while connecting the other end of the photoconductive element to one of output electrodes of the transistor and the other end of the resistive element to a predetermined voltage supply point. With this simple circuit arrangement, an effective input control with respect to the control electrode of the transistor can be realized.