1. Technical Field
The present disclosure relates to an image display device.
2. Description of the Related Art
Humans are capable of recognizing images three dimensionally through, for example, (1) focusing of crystalline lenses, (2) parallax between both eyes, which is a difference in how things look between left and right eyes, and (3) convergence of both eyes, which is movement of the eyes to make the lines of sight of the eyes intersect. In general, displays of game devices, TV sets, etc., have a two-dimensional display surface. Although images displayed on the display surface are two-dimensional, it is possible to make users recognize the two-dimensional images as three-dimensional images by utilizing the effects of the above-mentioned items (1) to (3). Displays including lenticular lenses, which have been commercialized, are an example of displays using the effects of the above-mentioned items (2) and (3).
Referring to FIG. 22, Japanese Unexamined Patent Application Publication No. 8-194273 discloses an image display device including lenticular lenses. A two-dimensional light emitting unit 21, such as a liquid crystal display, includes many pixels 21P. Each pixel 21P is divided into two regions, which are a region 21R and a region 21L. Lenticular lenses 20 are arranged on a surface of the light emitting unit 21 in one-to-one correspondence with the pixels 21P.
Owing to the focusing effect of each lenticular lens 20, light emitted from the region 21R of the corresponding pixel 21P is focused at a focusing point 4R, and light emitted from the region 21L of the corresponding pixel 21P is focused at a focusing point 4L. When the right and left eyes of a viewer are placed at the focusing points 4R and 4L, and different images are displayed on the regions 21R and 21L in consideration of the parallax, the viewer recognizes a three-dimensional image owing to the effects of the above-mentioned items (2) and (3). In other words, the right eye receives only an image formed by light emitted from the regions 21R, and the left eye receives only an image formed by light emitted from the regions 21L.
These two images are based on parallax information that corresponds to the parallax between both eyes. When the left and right eyes both look at the surface of the light emitting unit 21, the lines of sight intersect, in other words, convergence of both eyes occurs.