摘要:
A Fresnel lens sheet used for an image display device is disclosed. The Fresnel lens sheet is provided with a first prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is equal to or more than a predetermined incident angle and a second prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is less than the predetermined value.
摘要:
To eliminate or otherwise reduce non-uniform brightness of an image of a display apparatus, an image is projected through a projection optical system having a projection lens (2), curved surface reflection mirrors (4 and 5), and a reflection mirror (6) onto a rear surface of the rear-surface projection type screen (3). The rear-surface projection type screen includes a Fresnel lens sheet (8), wherein the prism surfaces of the Fresnel lens are formed in an aspheric configuration, thereby letting the light beams from the screen to exit at an exit angle of about zero (0) degree relative to a line perpendicular to the screen surface, over most of the entire surface thereof. It is possible to obtain a projection image that having uniform brightness in an image display apparatus while maintaining a thin cabinet (7) profile.
摘要:
A Fresnel lens sheet used for an image display device is disclosed. The Fresnel lens sheet is provided with a first prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is equal to or more than a predetermined incident angle and a second prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is less than the predetermined value.
摘要:
For dissolving ununiformity in the brightness of a projection image within a display image apparatus, obtaining an enlarged projection image through an oblique projection of image lights onto a rear-surface projection type screen, wherein an image from an image generating source 1 is projected through a projection optical system, having a projection lens 2, curved surface reflection mirrors 4 and 5, a reflection mirror 6, from a rear surface of the rear-surface projection type screen 3, within a housing 7 being narrow in depth thereof; the rear-surface projection type screen includes a Fresnel lens sheet 8, wherein the prism surfaces of the Fresnel lens making up the Fresnel lens sheet are formed in an aspheric configuration, thereby letting the light beams from the screen to exit at an exit angle of about zero (0) degree, almost all over the entire surface thereof. With this, it is possible to obtain a projection image, being uniform in the brightness thereof as a whole, and thin-sizing of the image display apparatus, as well.
摘要:
Both ends of a transparent cover which is formed of a curved member are fitted to a lens guard and a mirror guard, and a free-shaped surface mirror and a free-shaped surface lens are housed in a sealed space defined within a projection type image display device.
摘要:
Both ends of a transparent cover which is formed of a curved member are fitted to a lens guard and a mirror guard, and a free-shaped surface mirror and a free-shaped surface lens are housed in a sealed space defined within a projection type image display device.
摘要:
A fresnel lens sheet has a fresnel center in the vicinity of a lower end, and includes first and second fresnel lens portions respectively formed into concentrically circular shapes. The first fresnel lens portion exists inside a reference circumference, and the second fresnel lens portion exists outside the reference circumference. A conjugate point distance of the second fresnel lens portion is shorter than a conjugate point distance of the first fresnel lens portion. The reference circumference passes through vicinities of cross points between a horizontal centerline, which halves the fresnel lens sheet into upper and lower portions, and left and right ends of the fresnel lens sheet.
摘要:
An image that has been displayed on the display screen of an image generator 1 is first passed through a projection lens section 2 consisting of a front group and a rear group. Next after being reflected on the reflecting surface of a free-form surface mirror 5, the image is further reflected by a planar reflecting mirror 4 and then obliquely projected from the lower section of a projection screen 3 onto the screen 3. The front group of the projection lens section 2 is provided for enlarging the image. In order to correct aberration due to oblique projection onto the projection screen, the rear group uses a free-form surface lens that forms a concave shape with respect to the exit side of light from the lens. The free-form surface mirror 5 corrects trapezoidal distortion due to oblique projection onto the projection screen. The free-form surface lens in the rear group of the projection lens section 2 can accommodate changes in environmental conditions by using one edge as a reference edge and rendering the other edge expandable. The free-form surface mirror can likewise use one edge as a reference edge and render the other edge expandable. For adjustment, the free-form surface mirror can also be pivoted about the reference edge.
摘要:
A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.
摘要:
A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.