A total reflecting prism portion is formed on an image generation source side of a Fresnel lens sheet which constitutes a rear projection type screen. The total reflecting prism portion is formed in an area in which the angle of incidence of a projection image projected from an optical part on the Fresnel lens sheet is at least about 40. The total reflecting prism portion causes incident light to be outputted as output light at a predetermined output angle by a total reflection phenomenon after a first refraction phenomenon. A refracting prism portion is formed on an image monitoring side of the Fresnel lens sheet. The refracting prism portion is formed in an area opposed to the portion where the total reflecting prism portion is not formed. The refracting prism portion causes incident light to be outputted as output light at a predetermined output angle by a second refraction phenomenon.

 
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< Wide-angle projection lens for front projection display systems

> Drive controller for lens apparatus

> Variable optical delay circuit

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