Abstract: A lenticular lens provided on the viewer side of a transmission type screen is composed of at least two layers, that is, a surface layer and a base layer at least one of which contains a light dispersing material, and a visible light absorbing material is mingled in at least one of these two layers, or in the light dispersing material, thereby enhancing the image contrast of the transmission type screen.

Abstract: A lenticular lens provided on the viewer side of a transmission type screen is composed of at least two layers, that is, a surface layer and a base layer at least one of which contains a light dispersing material, and a visible light absorbing material is mingled in at least one of these two layers, or in the light dispersing material, thereby enhancing the image contrast of the transmission type screen.

Abstract: A projection television has a rear projection screen including a Fresnel lens and a lenticular lens, and a smoke sheet. The screen is characterized in that a dye or a pigment is mixed into the lenticular lens sheet or the smoke sheet which thereby has a waveform selection transmittance having the following transmittance values:.gtoreq.65% when incident light wavelength is <490 nm..ltoreq.60% when incident light wavelength is 490 nm-660 nm.wherein the transmittance, for incident light wavelength 490 nm-580 nm., is substantially different from the transmittance when the wavelength is 580 nm.-660 nm.

Abstract: A transmission-type video projection television system employs a transmission-type screen for displaying an image projected from a rear projector for visual observation by an observer in front of the screen. The transmission-type screen has Fresnel and lenticular lenses, one of which has an electrically conductive layer or a metal member on its surface to prevent the lens from being electrostatically charged, so that dust or dirt particles will not be attracted to the screen.

Abstract: A constant voltage converter for use with a cathode ray tube in which a voltage regulator is controlled by both the output of the regulator and beam current from the cathode ray tube by way of beam detecting means. The output of the regulator is applied separately to a stabilizing circuit including another feedback circuit for CRT, and also to deflection circuits so as to better prevent fluctuation of picture on the CRT.