Abstract: The disclosure provides a flow self-compensating load sensing pump/valve coordinated electro-hydraulic system, including a prime mover, an electronically controlled variable pump, a flow control valve, a hydraulic actuator, a shuttle valve, an electronic control joystick, a bypass control valve, two pressure sensors, a bypass throttle valve, and a control system, where an oil outlet of the shuttle valve is connected to a right spring chamber of the bypass control valve, a left chamber and an oil inlet of the bypass control valve are connected to an oil outlet of the electronically controlled variable pump, an oil inlet and an oil outlet of the bypass throttle valve are connected to an oil outlet of the bypass control valve and an oil tank, two ends of the oil inlet and the oil outlet of the bypass throttle valve are provided with the first pressure sensor and the second pressure sensor, respectively.

Abstract: A front projection screen includes a plane base layer forming a plurality of parallel outwardly-protruding annular bars on the light-reflecting side surface thereof. Each bar contains an outside surface facing the projection light source and being a light-reflecting portion, and an outside surface not facing the projection light source and being a stray-light absorbing portion. The two surfaces intersect each other. All bottom interfaces between the bars and the base layer are in a common plane. All outside surfaces of these bars have a common focus point. The outside surface is arranged in such a manner that the outside surface of each bar does not block the projection light incident on the whole outside surface of its adjacent bar.

Abstract: A rear projection screen does not block the image light and provides a perfect complete image. The screen includes a Fresnel lens, and a cylindrical lens array consisting of a plurality of cylindrical lens elements. These elements are independent from each other and in parallel, and arranged closely between adjacent cylindrical lens element, so that there are no luminous flux loss therebetween. A strengthening area, which is provided with a rigid reinforced member connecting with cylindrical lens elements on two sides thereof, is formed on the are a being from their contact portion to the image-light exist-side surface between adjacent cylindrical lens elements. An ambient light absorbing portion is formed at the image-light exit side in the strengthening area.