Abstract: A filtering unit for receiving an electronic device. The filtering unit includes a housing, a filter, a fan, a detector, and a controller. The housing includes an inlet. The filter is disposed at the inlet of the housing. The fan is disposed in the housing. The detector detects the number of particles in the filter. The controller is coupled to the fan and the detector. When the number of the particles in the filter exceeds a threshold value, the detector outputs a signal to the controller to change the rotating direction of the fan.

Abstract: A filtering unit for receiving an electronic device. The filtering unit includes a housing, a filter, a fan, a detector, and a controller. The housing includes an inlet. The filter is disposed at the inlet of the housing. The fan is disposed in the housing. The detector detects the number of particles in the filter. The controller is coupled to the fan and the detector. When the number of the particles in the filter exceeds a threshold value, the detector outputs a signal to the controller to change the rotating direction of the fan.

Abstract: A projector includes a housing, a first light source installed inside the housing for generating light beams, a second light source installed inside the housing for generating light beams, a first refractive element installed inside the housing for refracting the light beams generated by the first light source, a second refractive element installed inside the housing for refracting the light beams generated by the second light source to a direction parallel to a direction of the light beams refracted by the first refractive element substantially, a light pipe installed inside the housing for uniformizing light beams from the first refractive element and the second refractive element, and an image device installed inside the housing for processing the uniformized light from the light pipe and for projecting the processed light to form an image.

Abstract: A light source module, applicable in a projection display system, comprises a light source, a light-selection device and a reflective device. The light source provides an incident beam. The light-selection device is arranged on a light path of the incident beam, for passing one part of the incident beam through and reflecting the other parts to be a reflective beam. The reflective device is arranged between the light source and the light-selection device, for reflecting the reflective beam back to and passing through the light-selection device.

Abstract: A light source module, applicable in a projection display system, comprises a light source, a light-selection device and a reflective device. The light source provides an incident beam. The light-selection device is arranged on a light path of the incident beam, for passing one part of the incident beam through and reflecting the other parts to be a reflective beam. The reflective device is arranged between the light source and the light-selection device, for reflecting the reflective beam back to and passing through the light-selection device.

Abstract: The present invention discloses a projecting device without prisms. The projecting device comprises a light source for generating an incident light beam, a reflective image module comprising a plurality of reflective surfaces which can be separately controlled to generate the image-containing reflected light beam, a first lens set for concentrating the incident light beam, a reflective mirror for reflecting the incident light beam and concentrating the light beam through the first lens set onto the image module, and a second lens set installed between the light source and the reflective mirror for shortening an optical path from the light source to the reflective mirror. The optical path of the incident light beam reflected from the image module intersects a plane formed by the optical paths of the incident light beam from the light source to the reflective mirror and from the reflective mirror to the image module at one point, thus interference of the light beams is prevented.

Abstract: A traffic signal lamp includes a plurality of light emitting diodes and two lens sets. A first lens set has an entrance surface comprising a plurality of convex cylindrical surfaces running in a vertical direction and an exit surface comprising a plurality of slanted surface segments running in a horizontal direction. A second lens set has an entrance surface comprising a plurality of elongated concave cylindrical surfaces running in the vertical direction and an convex exit surface having a small curvature. The first lens set collimates light in the horizontal direction and limits light in a viewing angle in the vertical direction. The second lens set redistributes light uniformly in a viewing angle in the horizontal direction.

Abstract: A magnification-variation scanner modifies the resolution merely by changing the object distance and the image distance, with a constant focal distance. The scanner includes a light source, an object lens, an image detector, a holder for carrying the object lens, an optical path delay and a driver. The optical path delay can be located at the midway of the light path from the light source to the object lens, thereby modifying the optical path between the object surface and the object lens. In accompaniment with the movement of the object lens, the dimensions of the image projected over the image detector can be modified. The resolution can therefore be modified. The driver connects between the holder and the optical path delay.

Abstract: A liquid-crystal projection display system with higher efficiency is provided. The liquid-crystal projection display system comprises a double-layer square-pillar-like integrator, including an inner layer and an outer layer, having a polarization-separating thin film formed between the inner layer and the outer layer. The system also includes a converging light source for generating light converged at a point near one end surface of the double-layer square-pillar-like integrator, so that most light emitted from the light source enters the double-layer square-pillar-like integrator, and different polarized light is transmitted by being totally reflected off of surfaces of the inner layer and the outer layer respectively. A first lens is provided for forming real light spots on an image plane from virtual light spots formed by totally reflecting the different polarized light transmitted in the double-layer square-pillar-like integrator.