A highly integrated light valve is formed with a composite substrate formed of a quartz substrate and a monocrystalline silicon thin film layer bonded to the quartz substrate, in which an X driving circuit and a Y driving circuit are integrated utilizing very large scale integration processing. Driving electrodes are arranged in a matrix format on the composite substrate for providing signals output from the X driving circuit and the Y driving circuit to respective transistors and display pixel electrodes arranged at each intersection of the driving electrodes in the matrix. A control circuit for supplying timing signals to the X driving circuit and the Y driving circuit and a display data generating circuit for generating display data in order to display an image are also integrated on the composite substrate. A light source element driving circuit for driving a light source element is provided thereon for projecting a displayed image. A liquid crystal layer is sealed in a gap between the composite substrate and a second, opposed substrate with a sealing agent. The sealing agent is, for example, a resin which is stiffened by ultraviolet radiation and is supplied along a predetermined seal region. The present invention provides an improved structure for a light valve device having a high reliability, compact size, high pixel density and high resolution.