Abstract:
A zoom lens including a first lens group with a negative refractive power and a second lens group with a positive refractive power is provided. The first lens group includes a first lens, a second lens, and a third lens arranged from an object side to an image side in sequence. The refractive powers of the first, second, and third lenses are negative, negative, and positive sequentially. The second lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged from the object side to the image side in sequence. The refractive powers of the fourth, fifth, sixth, and seventh lenses are positive, positive, negative, and positive sequentially. The first lens group and the second lens group are capable of moving between the object side and the image side.
Abstract:
A zoom lens suitable for imaging an object on a photosensitive element is provided. The zoom lens includes a first lens group, a second lens group disposed between the first lens group and the photosensitive element, a third lens group disposed between the second lens group and the photosensitive element, and a fourth lens group. The second lens group is suitable for moving between the first lens group and the third lens group. The third lens group includes two lenses having positive refractive power. The fourth lens group is disposed and suitable for moving between the third lens group and the photosensitive element. The refractive powers of the first lens group, the second lens group, the third lens group, and the fourth lens group are a positive value, a negative value, a positive value, and a positive value respectively.
Abstract:
A color wheel includes a fixing base, a ring filter, a washer, and a fixing ring. The fixing base has a protrusion portion and a supporting portion. The ring filter is fit on the protrusion portion. An inner margin of the ring filter leans on the supporting portion. The washer is connected to the protrusion portion. The ring filter is disposed between the washer and the supporting portion. The washer and the supporting portion clip the inner margin of the ring filter. The fixing ring has an annular supporting portion, a side wall surrounding the annular supporting portion, and fixing blocks connected to the side wall and dotted on an outer margin of the ring filter. The outer margin of the ring filter leans on the annular supporting portion. The fixing blocks, the side wall, and the annular supporting portion clip the outer margin of the ring filter.
Abstract:
A zoom lens for imaging an image onto a photosensitive element includes a first lens group, a second lens group, a third lens group and a fourth lens group. The second lens group is located and suitable for moving between the first lens group and the third lens group; the fourth lens group is located and suitable for moving between the third lens group and the photosensitive element. The first lens group, the second lens group, the third lens group, and the fourth lens group have a positive refractive power, a negative refractive power, a positive refractive power and a positive refractive power, respectively. Besides, the third lens group includes at least a hybrid lens and the second lens group includes at least an aspheric lens, the number of the aspheric lens is smaller than or equal to 2. Thus, manufacturing cost of the zoom lens mentioned above is lower.
Abstract:
A zoom lens suitable for imaging an object on a photosensitive element is provided. The zoom lens includes a first lens group, a second lens group disposed between the first lens group and the photosensitive element, a third lens group disposed between the second lens group and the photosensitive element, and a fourth lens group. The second lens group is suitable for moving between the first lens group and the third lens group. The third lens group includes two lenses having positive refractive power. The fourth lens group is disposed and suitable for moving between the third lens group and the photosensitive element. The refractive powers of the first lens group, the second lens group, the third lens group, and the fourth lens group are a positive value, a negative value, a positive value, and a positive value respectively.
Abstract:
In a projection display, input light is separated by a polarization beam splitter prism into first and second color components, and a third color component. The first and second color components, together with a light leakage component that is associated with the third color component, are directed by the polarization beam splitter prism to a color synthesizing prism or a color splitter prism set, which then separates the first and second color components and the light leakage component so as to travel in three different directions, respectively. The first and second color components from the color synthesizing prism or the color splitter prism set, and the third color component from the polarization beam splitter prism are processed by reflective first, second and third light modulators, respectively.
Abstract:
A triple-lens type projection display includes a source for generating a white primary beam output, a first beam splitter for splitting the white primary beam output into a first color component and a secondary beam output, a second beam splitter for splitting the secondary beam output into a second color component and a third color component, first, second and third light modulators for modulating the first, second and third color components, respectively, a first projection lens for receiving the first color component from the first light modulator, a second projection lens for receiving the second color component from the second light modulator, and a third projection lens for receiving the third color component from the third light modulator. Each of the first, second and third color components has a respective optical path length that is measured from the first beam splitter to a respective one of the first, second and third light modulators. The optical path lengths of the first, second and third color components are equal.
Abstract:
An illumination device and an image display apparatus using the same. The illumination device comprising a light source, an illumination uniformizing device, and a polarization converter. The image display apparatus comprises an illumination device provided in the invention, a synthesizing device, and a projection device.
Abstract:
An LCD projector of two-plate type is disclosed. The LCD projector comprises a light source, a color valve, a dichroic mirror, a polarization rotating device, a polarization beam splitter, a first reflective LCD panel, a second LCD panel and a projection lens. The first reflective LCD panel is used to modulate the green light with the green component of the image signal. The red light and the blue light are modulated in a time field sequential manner by the color valve and the second reflective LCD panel.
Abstract:
A projection display is used to process a light beam that includes first, second and third color components and that is to be provided to a projection lens. The projection display includes a dichroic beam splitter which separates the first color component from the second and third color components. A first polarization beam splitter prism cooperates with a first reflective light valve to process the first color component. A second polarization beam splitter prism cooperates with second and third reflective light valves to process the second and third color components. A third polarization beam splitter prism is disposed so as to direct the processed color components from the first and second polarization beam splitter prisms to the projection lens.