Abstract: A projection-type display apparatus includes a liquid crystal panel including a panel pixel, an optical path shifting element that shifts a projected pixel projected from the panel pixel, and a display control circuit that controls the liquid crystal panel and the optical path shifting element. The display control circuit supplies, to the liquid crystal panel, the same data signal and controls the projected pixel to be at a same position in each of a unit period f1-1 and a unit period f2-1, and controls the optical path shifting element to cause a shift direction from the projected pixel before the shift toward the projected pixel after the shift from a unit period f1-2 to a unit period f1-4 to be opposite to the shift direction from the projected pixel before the shift toward the projected pixel after the shift from a unit period f2-2 to a unit period f2-4.

Abstract: A projection-type display apparatus includes a liquid crystal panel including a panel pixel, an optical path shifting element that shifts a projected pixel projected from the panel pixel, and a display control circuit that controls the liquid crystal panel and the optical path shifting element. The display control circuit supplies, to the liquid crystal panel, the same data signal and controls the projected pixel to be at a same position in a unit period f1-1 and a unit period f2-1 period, and controls the optical path shifting element to cause the position of the projected pixel in each of a unit period f1-2 to a unit period f1-4, to be different from the position of the projected pixel in a respective one of a unit period f2-2 to a unit period f2-4.

Abstract: The present optical position detection method and the apparatus therefor is adapted to compute an arithmetic mean of the adjusted light reception values received by adjacent photodetectors as the virtual light reception value at the virtual position, compare not only the adjusted light reception values of the respective photodetectors but also the virtual light reception values with the reference level and utilize the virtual position also as the light interruption position data when light interruption is determined, thus enhancing the accuracy of detecting the position of an object.

Abstract: An optical detector or an optically detecting apparatus comprises divider means for outputting not only a light source flash signal which divides an oscillation signal with frequency higher than that of an expected disturbance light but also an operating time signal divided into a divided ratio a plurality of times longer than the first mentioned divided ratio, shift means for successively shifting a light signal receptive to a light receptive element by a clock input synchronous with the oscillation signal during the time when the operating time signal is inputted, and means for outputting a light detection signal when the shift output corresponds to the set value as compared with one another and terminating the light detection signal when the operating time signal is terminated.