Illumination device and display apparatus including same

Abstract

A display apparatus is constituted by a planar display device and a planar illumination device therefor. A lowering in light quantity at a periphery of the planar illumination device is prevented by inserting a reflection member, such as a reflection frame, having an inside reflection surface along the periphery of the illumination device, or a combination of a scattering means and a transparent sheet member between the display device and the illumination device. A plurality of the display apparatus may be combined to allow an associate movement thereof so as to constitute a composite display apparatus, such as a head-mount display.

What is claimed is:  
     
         1 . A display apparatus, comprising at least: a liquid crystal display device for image display, a backlight for illuminating the liquid crystal display device, and a reflection member having a size almost equal to an outer frame of the liquid crystal display device and disposed insertable between the liquid crystal display device and the backlight.  
     
     
         2 . A display device according to  claim 1 , further comprising a support and control mechanism for supporting the reflection member so as to allow a movement of the reflection member and controlling a position of the reflection member.  
     
     
         3 . A display device according to  claim 2 , further comprising a position sensor for detecting a position of a unit composed of the liquid crystal display device and the backlight, a control circuit for supplying a control signal to the support and control mechanism so as to control the position of the reflection member, and a backlight support member for supporting the backlight in proximity to the liquid crystal display device.  
     
     
         4 . A display device according to  claim 3 , wherein said position sensor, said control circuit and said reflection member support and control mechanism function to provide a first state wherein said reflection member is inserted between and parallel to the liquid crystal display device and the backlight and in alignment with the outer frame of the liquid crystal display device, and a second state wherein said reflection member retracts from between the liquid crystal display device and the backlight and the backlight is moved to a close proximity to the liquid crystal display device.  
     
     
         5 . A display apparatus, comprising at least two display apparatus each according to  claim 4 .  
     
     
         6 . A display apparatus according to  claim 5 , wherein, in each of said at least two display apparatus, the reflection member assumes said first state when the unit of the liquid crystal display device and the backlight is at a first position and said second state when the unit is at a second position different from the first position, and the units in the respective display apparatus are moved in association with each other.  
     
     
         7 . An illumination device, comprising: a light source, a scattering means disposed contiguous to the light source for scattering emitted light from the light source when the emitted light passes the scattering means, and a transparent sheet member disposed contiguous to the scattering means.  
     
     
         8 . An illumination device according to  claim 7 , wherein the sheet member has a refractive index n, and a medium having a refractive index n′ is disposed on a transmitted light side of the sheet member so as to satisfy n>n′.  
     
     
         9 . An illumination device according to  claim 7 , wherein a prism device is disposed on a surface of the sheet member of the sheet member so as to deflect the transmitted light through the sheet member toward a direction closer to a normal to the sheet member.  
     
     
         10 . A display apparatus, comprising: an illumination device according to  claim 7 , and a display device illuminated with the illumination device to display various data.  
     
     
         11 . A display apparatus according to  claim 10 , wherein the illumination device has a larger area than the display device including a marginal surface area outside the display device, said marginal surface area is covered with a light-shielding means so as to avoid unnecessary illumination light.  
     
     
         12 . An illumination device, comprising: a light source having a diffusion surface, and a reflection member disposed vertical to the diffusion surface along an edge of the diffusion surface and having at least one inside surface forming a reflecting surface.  
     
     
         13 . An illumination device, comprising: a light source having a diffusion surface, a triangular prism array disposed contiguous to the diffusion surface, and a reflection member disposed vertical to the diffusion surface along an edge of the diffusion surface and having at least one inside surface forming a reflecting surface.  
     
     
         14 . An illumination device according to  claim 12  or  13 , wherein said light source has a two-dimensional size larger than that of an illumination object, and a light-shielding plate is disposed in almost parallel with the diffusion surface, the light-shielding plate having an opening with a size almost equal to the two-dimensional size of the illumination object.  
     
     
         15 . A display apparatus, comprising: an illumination device according to  claim 12  or  13 , and a display device as an illumination object.