Abstract: A reception quality measurement device includes a rate changing unit configured to downsample at least either a first sample sequence of a received signal with a first sampling rate or a second sample sequence of the received signal having a second sampling rate to adjust the sampling rates of the first sample sequence and the second sample sequence to a common sampling rate, and a power calculation unit configured to calculate a power intensity according to a cumulative total power of a predetermined number of samples included in either the first sample sequence or the second sample sequence with the common sampling rate.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group and a positive third lens group, in this order from the object. The second lens group includes a cemented lens having a positive first lens element and a negative second lens element, and a meniscus lens element having the concave surface facing toward the image. The zoom lens system satisfies the following conditions: ?0.4<f23/f24<0.4??(1) 0.7<f3/ft<1.3??(2) wherein f23: the combined focal length of the cemented lens; f24: the focal length of the meniscus lens element; f3: the focal length of the third lens group; and ft: the focal length of the zoom lens system at the long focal length extremity.

Abstract: A rear-projection type projecting device enlarging and projecting an image displayed by a display device onto a screen, including a projecting optical system including a first optical system having a positive power and a second optical system having a reflection surface with a positive power, and a plane mirror attached to the projecting device to form a substantially right angle with respect to the screen and to reflect light emerging from the projecting optical system to the screen, wherein an effective reflection area of the reflection surface with the positive power is located at a position farther from an optical axis of the first optical system when viewed from the plane mirror.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group and a positive third lens group, in this order from the object. Upon zooming, the first lens group, the second lens group and the third lens group are moved along the optical axis. The first lens group includes a negative first lens element, a negative second lens element, and a positive third lens element. The second lens group includes a cemented lens having a positive first lens element and a negative second lens element, and a meniscus lens element having the concave surface facing toward the image. The zoom lens system satisfies the following conditions: ?0.4<f23/f24<0.4??(1) 0.7<f3/ft<1.3??(2) wherein f23: the combined focal length of the cemented lens; f24: the focal length of the meniscus lens element; f3: the focal length of the third lens group; and ft: the focal length of the zoom lens system at the long focal length extremity.

Abstract: There is provided an optical projection system which includes a display device, a first optical system that has a positive power in total and has a first lens group and a second lens group, a second optical system having a reflective surface having a negative power, and a first deflecting system that directs a light beam emerging from the first optical system to the second optical system. The first lens group and the second lens group have a positive power and a negative power, respectively. The first deflecting system is located over the first optical system in a cross sectional plane. The first deflecting system deflects the light beam in a direction moving away from the screen to direct the light beam to the second optical system. The optical projection system satisfies conditions: 6.0>D/f1>2.6 ?1>EXP1/f1>?2.

Abstract: A projection device includes an image source unit, a first projecting optical system, an intermediate optical system, and a second projecting optical system. The image displaying area of the image source unit is tilted with respect to a first virtual plane, and an intermediate image is tilted with respect at least the first virtual plane. A following relationship is satisfied: - 1 > tan ? ? ?2 tan ? ? ?1 > f ? ? 1 H 2 ? sin ? ? ?1 where, f1 denotes a focal length of the first projecting optical system, ?1 denotes a tilt angle of the image display surface of the image source unit with respect to the first virtual plane, H represents a length of the image source unit which corresponds to the image projected on the screen in the vertical direction, and ?2 denotes a tilt angle of the intermediate image with respect to the first imaginary surface.

Abstract: A projection device is provided with an image source unit, the image source, a first projecting optical system, an intermediate optical system and a second projecting optical system. Optical axes of the first and second projecting optical systems as developed are on a same plane. The image source is tilted, and then the center of the image source is translated in a direction spaced from the first projecting optical system within a plane including the image displaying area of the image source ;unit. In the above configuration, a relationship below may be satisfied: 0<S1?(H/2)×?tan?, where, ? denotes an absolute value of tilt angle, S1 denotes a shift amount of the image source, H denotes a width of the image source within the same plane.

Abstract: A projection device includes an image source unit, a first projecting optical system, an intermediate optical system, and a second projecting optical system. The image displaying area of the image source unit is tilted with respect to a first virtual plane, and an intermediate image is tilted with respect at least the first virtual plane. A following relationship is satisfied: - 1 > tan ? ? ? ?2 tan ? ? ? ?1 > f ? ? ? 1 H 2 ? sin ? ? ? ?1 where, f1 denotes a focal length of the first projecting optical system, ?1 denotes a tilt angle of the image display surface of the image source unit with respect to the first virtual plane, H represents a length of the image source unit which corresponds to the image projected on the screen in the vertical direction, and ?2 denotes a tilt angle of the intermediate image with respect to the first imaginary surface.

Abstract: A projecting device includes a first projective optical system forming an intermediate image having trapezoidal distortion from light emitted by a display unit displaying a rectangular image, a second projective optical system projecting the light from the intermediate image obliquely onto a screen so that an enlarged image in which the trapezoidal distortion has been corrected will be projected on the screen, and an intermediate optical system leading the light to combine the two projective optical systems. The second projective optical system includes at least one lens having a surface on which first and second ray bundles emitted from both ends of the image displayed by the display unit in regard to a short side direction of the image are totally separate from each other. A prescribed lens included in the at least one lens is configured so that gradients and curvatures at particular positions will satisfy prescribed conditions.

Abstract: A projection device is provided with an image source configured to emit light carrying an image having a rectangular shape, a first projecting optical system configured to form an intermediate image carried by the light emitted by the image source, the intermediate image having a trapezoidal shape due to trapezoidal distortion, an intermediate optical system configured to deflect light forming the intermediate image, a second projecting optical system configured to obliquely project light deflected by the intermediate optical system to a screen of the projection device, the image projected on the screen having a shape similar to the image provided by the image source. Each of the first projecting optical system and the second projecting optical system may be configured to be substantially telecentric toward the intermediate image.