Abstract: The setting distance between a DMD element and a projection lens is maintained accurately to display a high-quality image on a screen or the like. A projection lens unit is one in which light from a light source lamp side is reflected on the DMD element as image light and is subsequently projected at a projection lens. The projection lens unit includes a coupling tool that fixes the DMD element and the projection lens integrally in a state where the distance therebetween is accurately supported to a set value. The coupling tool has a color wheel fitting portion positioning and supporting a color wheel, a relay lens fitting portion positioning and supporting a relay lens, a reflection mirror fitting portion positioning and supporting a reflection mirror, a DMD element mounting portion in which the DMD element is mounted and supported, and a projection lens portion in which the projection lens is mounted and supported.

Abstract: A projection lens unit includes a main body; a lens fixed to the main body; and a hood disposed to one end of the main body close to a screen. The hood defines the outermost boundary of a view angle stretching with respect to the center of the lens and includes a light-shielding plate and a light-shielding barrel. When the shielding height of the light-shielding plate and the length of the light-shielding barrel are respectively represented by H and L, the shielding height H and the length L are set so as to satisfy the equation tan(?/2)=H/L, in relation to the view angle ?. More particularly, these dimensions are set so as to satisfy the condition that the ratio H/L lies in a range from 0.74 to 0.94. The inner surface of the light-shielding barrel is subjected to surface treatment so as to absorb unnecessary light thereby, reflect it thereat, or scatter it thereat. To be more specific, the light-shielding barrel has scattering grooves disposed on the inner surface thereof.

Abstract: A projection lens unit compensates for thermal expansion and contraction. The unit comprises a coupler at the front surface of a CRT, a lens unit body for projecting an image onto a screen by controlling and magnifying the light from the CRT, a plurality of legs secured to the coupler for supporting the lens unit body at more than three points, a slide mechanism (latch arms and latch engaging slots provided between the legs and the lens unit body for slidably supporting the legs for movement along the optical axis relative to the lens unit body, and expansion/contraction bars provided between the legs and the lens unit body for compensating for the thermally induced expansion/contraction, with one end engaged with a leg and the other end engaged with the base of the lens unit body.

Abstract: A projection lens, for enlarging and projecting a picture formed on a flat fluorescent plate of a CRT projection tube, includes: a first lens unit of a plus lens, having aspheric surfaces on both surfaces, being convex to the screen side at a central portion including an optical axis, a second lens unit of a minus lens, having aspheric surfaces on both surfaces, being concave to the screen side at a central portion including an optical axis; a third lens unit of a plus lens, having spherical surfaces on both surfaces, being convex on both sides; a fourth lens unit of a plus lens, having aspheric surfaces on both surfaces thereof, being curved in concave-like to the screen side, on a peripheral portion far from the optical axis into a radial direction; and a fifth lens unit of a minus lens, being made up with a transparent liquid, commonly serving a faceplate of the CRT projection tube and a cooling, and a meniscus lens, having a thickness being nearly equal to and at least an aspheric surface directing a conc

Abstract: An object of the present invention is to suppress an influence due to temperature change and various aberrations. It is a projection lens which projects an image on a surface of a screen (magnified side). A first group I having a negative refractive power and a second group II having a positive refractive power are arranged in order from a magnified side toward a reduced side. The first group I is configured to arrange a first lens and a second lens in order from the magnified side, and the second group II is configured to arrange a third lens to a seventh lens. The first and second lenses are a negative meniscus lens whose both surfaces are formed by the aspherical surface in which an area near an optical axis of the surface on the magnified side is a concave surface. The third lens is a cemented lens in which a bi-concave lens is cemented to the surface on the reduced side of a bi-convex lens.

Abstract: A color image projecting device includes an illuminating optical system and a projection optical system. The illuminating optical system includes a light source emitting white light including red, green, and blue colors, a dividing-spectra block having reflecting surfaces reflecting the red and blue colors of the light received from the light source toward left and right while transmitting the green color, a red block having a dichroic mirror provided in contact with the dividing-spectra block and reflecting the red color, reflected off the reflecting surface of the dividing spectra block, toward the projection optical system, a blue color block having a dichroic mirror like that of the red block, and a green block having a dichroic mirror reflecting the transmitted green color of light toward the projection optical system.

Abstract: A projection lens unit includes a main body; a lens fixed to the main body; and a hood disposed to one end of the main body close to a screen. The hood defines the outermost boundary of a view angle stretching with respect to the center of the lens and includes a light-shielding plate and a light-shielding barrel. When the shielding height of the light-shielding plate and the length of the light-shielding barrel are respectively represented by H and L, the shielding height H and the length L are set so as to satisfy the equation tan(&agr;/2)=H/L, in relation to the view angle &agr;. More particularly, these dimensions are set so as to satisfy the condition that the ratio H/L lies in a range from 0.74 to 0.94. The inner surface of the light-shielding barrel is subjected to surface treatment so as to absorb unnecessary light thereby, reflect it thereat, or scatter it thereat. To be more specific, the light-shielding barrel has scattering grooves disposed on the inner surface thereof.

Abstract: A projection lens unit, which is small, compatible and highly capable of compensating for the changes in temperature, is provided. The unit comprises a coupler 5 provided at the front surface of a CRT 1, a lens unit body 6 for projecting an image onto a screen by controlling and magnifying the light from the CRT 1, a plurality of leg portions 7 secured to the coupler 5 for supporting the lens unit body 6 at more than three points, a slide mechanism (latches 58 and latch engaging slots 42) provided between the leg portions 7 and the lens unit body 6 for slidably supporting the leg portions 7 in the direction of optical axis in relation to the lens unit body 6, and an expansion/contraction bars 8 provided between the leg portions 7 and the lens unit body 6 for compensating for the effect of heat with one end engaged with the tip end side of the leg portions 7 and the other end with the base end side of the lens unit body 6.

Abstract: A lens apparatus for projection includes a plurality of lenses on an optical axis. A shading plate 11 for covering the peripheral portion of the lens to block off light entering the peripheral portion is provided as a single member on the optical axis with the lenses to omit an inking process. In addition, the shading plate 11 is integrally provided with a contrast compensating plate 13 for compensating a projected image, so that it is not required to provide any portions for supporting the contrast compensating plate 13. Moreover, a shading wall 23 for blocking off light leaking out of the peripheral portion of the lens is provided on the peripheral portion of the shading plate 11. Thus, it is possible to provide a lens apparatus for projection, which has a simple structure and which can be easily assembled to reduce the producing costs.

Abstract: A lens apparatus for projection includes a plurality of lenses on an optical axis. A shading plate 11 for covering the peripheral portion of the lens to block off light entering the peripheral portion is provided as a single member on the optical axis with the lenses to omit an inking process. In addition, the shading plate 11 is integrally provided with a contrast compensating plate 13 for compensating a projected image, so that it is not required to provide any portions for supporting the contrast compensating plate 13. Moreover, a shading wall 23 for blocking off light leaking out of the peripheral portion of the lens is provided on the peripheral portion of the shading plate 11. Thus, it is possible to provide a lens apparatus for projection, which has a simple structure and which can be easily assembled to reduce the producing costs.

Abstract: The prism assembly of the present invention includes: a prism made of plastics having light transmittivity; and a glass plate which is joined to a plane of the prism obliquely intersecting a light incidence plane of the prism and whose one surface carries a dichroic layer formed thereon.

Abstract: The present invention relates to a projection lens including: a power lens unit; one or more image-side lens units, provided on the image side with respect to the power lens, for correcting an aberration; and one or more opposite-image-side lens units, provided on the side opposite to the image side with respect to the power lens, for correcting an aberration, which projection lens has the following features.

Abstract: The laser pointer of this invention includes: a laser pointer main body for emitting a visible laser beam; and a deflection optical element disposed on the central axis of the laser beam and adapted to deflect the direction along which the emitted laser beam passes.

Abstract: This projection lens for a projection television includes coaxially in order towards the face plate of the CRT: a first lens of negative power, both of whose surfaces are aspherical; a second lens of positive power, at least one of whose surfaces is aspherical, formed of a plastic material; a third lens of positive power; a fourth lens of positive power, at least one of whose surfaces is aspherical, formed of a plastic material; and a back lens of negative power, which presents in the direction away from the face plate of the CRT a face of strongly concave curvature. The third lens is the strongest of the lenses in absolute power, and the second lens and the fourth lens have substantially the same optical characteristics, and are disposed in reverse orientation on opposite sides of the third lens. Certain conditions relating to lens parameters should be satisfied for acceptable optical performance.