Abstract: A wavelength conversion element includes a substrate made of LiTaO.sub.3 of non-linear medium, a three-dimensional waveguide formed in the substrate and a second harmonic generation portion for defining a change in refractive index in the waveguide with a period .LAMBDA. and generating a second harmonic of a fundamental wave introduced into the wave guide, where .LAMBDA.=2 m.pi./{.beta.(2.omega.)-2.beta.(.omega.)}, m is a natural number, .omega. is a frequency of fundamental harmonic, .beta.(.omega.) is a propagation constant of the fundamental wave, and .beta.(2.omega.) is a propagation constant of second harmonic.

Abstract: A wavelength conversion element includes a substrate made of LiTaO.sub.3 of non-linear medium, a three-dimensional waveguide formed in the substrate and a second harmonic generation portion for defining a change in refractive index in the waveguide with a period .LAMBDA. and generating a second harmonic of a fundamental wave introduced into the wave guide, where .LAMBDA.=2m.pi./{.beta.(2.omega.)-2.beta.(.omega.)}, m is a natural number, .omega. is a frequency of fundamental harmonic, .beta.(.omega.) is a propagation constant of the fundamental wave, and .beta.(2.omega.) is a propagation constant of second harmonic.

Abstract: An arrangement for detecting sizes of original documents for use in a copying apparatus or the like, which is capable of effecting size detection at high reliability irrespective of thicknesses of original documents, and in which an adverse effect due to cross-talk light by neighboring light emitting elements employed in it is eliminated for detection of various sizes based on presence of correct original documents.

Abstract: A pressure responsive switch having an atmospheric pressure chamber including electrical contacts which are sealed hermetically by a flexible pleated cover whereby the flexible pleated cover deforms in accordance with the expansion and contraction of the atmosphere in the atmospheric pressure chamber. The alteration of the temperature surrounding the atmospheric chamber provides for the expansion and contraction of the atmosphere with the atmospheric pressure chamber and the pleated cover maintains the atmospheric pressure constant within the pressure chamber.

Abstract: A circuit for providing a constant coloring current to a plurality of segment electrodes of an electrochromic display comprises a plurality of switching elements, say, transistors respectively connected to the segment electrodes for enabling the application of the constant coloring current to the segment electrodes, and an element for changing switching timings of the switching elements. A desirable amount of charge derived from the constant coloring current is applied to the segment electrodes regardless of the presence of the variations in electrical properties of the respective switching elements. In another form of the present invention, the changing element comprises a generator for generating a constant voltage, and a modifier for modifying a value of the constant voltage.

Abstract: A charger, which is useful to power a variety of compact type electronic appliances such as an electronic wristwatch, includes one or more solar batteries as a primary battery, and a sealed type silver oxide battery as a secondary battery. Both the amount of charging current amplitude and of charging voltage are limited to protect the sealed silver oxide battery from its own expanse phenomenon.

Abstract: An electronic timepiece comprising an electrochromic display device for digital information display. A detection means is provided for developing a detection output when power supply from a power supply source is initiated. The detection output is applied to a driver circuit of the electrochromic display device in order to bleach the entire display segments, thereby ensureing accurate information display.

Abstract: An information reader for optically reading information recorded in the form of an array of aligned embossments on a card, comprising a slit plate positioned over a card transport table having two slits, one for directing incident light toward the embossed card and the other for leading to a light-sensitive element series light which has passed past the first named slit and then reflected from a planar surface or raised surface of the embossed card. While the information containing card causes reciprocating motion on the card transport table at a fixed rate, light passed past the last named slit is detected in a storage mode by sequentially scanning the multiple light-sensitive elements so that pattern recognition for the recorded information is carried out by measuring the detection light.