Abstract: The LED display system includes LED displays arranged in a matrix and a control device to control the LED displays. Each LED display includes a first display part including first LEDs provided on a display surface for displaying video, a second display part including at least one second LED provided on the other surface, a luminance measurement part to measure the luminance of the second LED, a first driving part to drive each first LED, and a second driving part to drive the second LED. The control device computes a luminance drop characteristic for each of the driving conditions on the basis of the luminance of the second LED, and corrects a luminance of the video on the basis of one luminance drop characteristic and the accumulative lighting-up time. The control device performs control to cause the LED displays to display the video after the correction of the luminance.

Abstract: A display device of the present invention includes a first display unit, a second display unit, a lighting time storage configured to store first cumulative lighting times of the of first light emitting elements of the first display unit, a light receiving unit configured to measure luminance of the second light emitting elements, a luminance transition storage configured to associate the luminance of the second light emitting elements with a second cumulative lighting time and store thereof, and a luminance corrector configured to correct luminance of the first light emitting elements based on the first cumulative lighting time, the luminance of the second light emitting elements, and the second cumulative lighting time.

Abstract: A projection type display includes an illumination optical system provided with a light source including, for respective predetermined colors, LED arrays each formed of six LEDs, a light source controller that controls the LED arrays to turn on, an integration device, and a DMD, wherein the light source controller controls the LED arrays to turn on such that the shapes of light source images, which are formed on an entrance surface of the integration device by five LEDs of the respective LED arrays, coincide with each other.

Abstract: A projection type display includes an illumination optical system provided with a light source including, for respective predetermined colors, LED arrays each formed of six LEDs, a light source controller that controls the LED arrays to turn on, an integration device, and a DMD, wherein the light source controller controls the LED arrays to turn on such that the shapes of light source images, which are formed on an entrance surface of the integration device by five LEDs of the respective LED arrays, coincide with each other.

Abstract: A package structure prevents an optical sheet from being brought into contact with a display panel and making scratches on the display panel due to motion caused during transport of a display device, thereby minimizing cost increase. A package structure for a thin display device is the structure for storing the thin display device in a package case. The thin display device includes at least one optical sheet situated in approximately parallel with its display surface, and the package case includes a storage member for holding a thin display device with the optical sheet having a surface inclined relative to a vertical direction.

Abstract: A light source device (100) includes a discharge lamp (1), a reflection mirror (2), a transparent plate (3) and a case (7). The reflection mirror (2) has inlet openings (4a, 4b) and outlet openings (5a, 5b) formed in the vicinity of the front end of the reflection mirror (2). The case (7) has outlet openings (7a, 7b) disposed on the front side of the reflection mirror (2), and an inlet opening (7c) disposed on the rear side of the reflection mirror (2). The inlet opening (7c) of the case (7) allows an air to flow into the case (7) and to flow along a back surface (2b) of the reflection mirror (2). The inlet openings (4a, 4b) of the reflection mirror (2) allow the air to flow into the interior of the reflection mirror (2). The outlet openings (5a, 5b) of the reflection mirror (2) and the outlet openings (7a, 7b) of the case (7) allow the air to be exhausted out of the case (7).

Abstract: A package structure prevents an optical sheet from being brought into contact with a display panel and making scratches on the display panel due to motion caused during transport of a display device, thereby minimizing cost increase. A package structure for a thin display device is the structure for storing the thin display device in a package case. The thin display device includes at least one optical sheet situated in approximately parallel with its display surface, and the package case includes a storage member for holding a thin display device with the optical sheet having a surface inclined relative to a vertical direction.

Abstract: A light source device (100) includes a discharge lamp (1), a reflection mirror (2), a transparent plate (3) and a case (7). The reflection mirror (2) has inlet openings (4a, 4b) and outlet openings (5a, 5b) formed in the vicinity of the front end of the reflection mirror (2). The case (7) has outlet openings (7a, 7b) disposed on the front side of the reflection mirror (2), and an inlet opening (7c) disposed on the rear side of the reflection mirror (2). The inlet opening (7c) of the case (7) allows an air to flow into the case (7) and to flow along a back surface (2b) of the reflection mirror (2). The inlet openings (4a, 4b) of the reflection mirror (2) allow the air to flow into the interior of the reflection mirror (2). The outlet openings (5a, 5b) of the reflection mirror (2) and the outlet openings (7a, 7b) of the case (7) allow the air to be exhausted out of the case (7).

Abstract: A retrofocus projection lens system comprising, in order from a large conjugate side a first lens group having a negative refracting power and including a plurality of lenses, a second lens group having a positive refracting power, and a third lens group having a positive refracting power and including a plurality of lenses. The lens of the first lens group which is nearest to the large conjugate side is an aspherical lens, and the lens of the third lens group which is nearest to a small conjugate side is an aspherical lens. The retrofocus projection lens system desirable satisfy the following conditional expressions (1) to (3):1.8<D.sub.1 /f<3.0 (1)1.1<f.sub.2 /f.sub.3 <1.6 (2)1.5<.vertline.f.sub.1 .vertline./f<2.3 (3)where a symbol f.sub.1 designates a focal length of the first lens group, a symbol f.sub.2 designates a focal length of the second lens group, a symbol f.sub.

Abstract: A light source device including a light emitting element emits a luminous flux, which is converged by a reflecting mirror. A conical light-refracting element receives the luminous flux converged by the reflecting mirror and changes the cone angle of the luminous flux. The luminous flux exiting the conical light-refracting element is diffused by a holographic diffuser and is then converged by at least one lens. The reflecting mirror may have an elliptic curvature or a parabolic curvature. The light source device is also used to form a projector for a projection type display apparatus. In the projector, the luminous flux emitted from the light source device may be separated by color separators into a plurality of colors of light. Then, each color of light is directed to the corresponding one of a plurality of light valves. Then, a color synthesizer synthesizes the colors of light emitted from the light valves into a composite image which in turn is projected onto a screen.