Scanned display with pinch, timing, and distortion correction

#The present invention relates to scanned light devices and, more particularly, to scanned light beam displays and imaging devices that produce images for viewing or collecting images.

#A variety of techniques are available for providing visual displays of graphical or video images to a user. For example, cathode ray tube type displays (CRTs), such as televisions and computer monitors are very common. Such devices suffer from several limitations. For example, CRTs are bulky and consume substantial amounts of power, making them undesirable for portable or head-mounted applications.

#Flat panel displays, such as liquid crystal displays and field emission displays, may be less bulky and consume less power. However, typical flat panel displays utilize screens that are several inches across. Such screens have limited use in head mounted applications or in applications where the display is intended to occupy only a small portion of a user's field of view.

#FIG. 1 is a diagrammatic representation of a display aligned to a viewer's eye.

#FIG. 2A is a combined image perceived by a user resulting from the combination of light from an image source and light from a background.

#FIG. 2B is an image perceived by a user from the display of FIG. 1 where the background light is occluded.

#As shown in FIG. 6, a scanned beam display 70 according to one embodiment of the invention is positioned for viewing by a viewer's eye 72. The display 70 includes four principal portions, each of which will be described in greater detail below. First, control electronics 74 provide electrical signals that control operation of the display 70 in response to an image signal VIM from an image source 76, such as a computer, television receiver, videocassette player, or similar device.

#The second portion of the display 70 is a light source 78 that outputs a modulated light beam 80 having a modulation corresponding to information in the image signal VIM. The light source 78 may utilize coherent light emitters, such as laser diodes or microlasers, or may use non-coherent sources such as light emitting diodes. The light source 78 may be a directly modulated light emitter such as a light emitting diode (LED) or may be include a continuous light emitter indirectly modulated by an external modulator, such as an acousto-optic modulator.

#The third portion of the display 70 is a scanning assembly 82 that scans the modulated beam 80 of the light source 78 through a two-dimensional scanning pattern, such as a raster pattern. The scanning assembly will be described in greater detail below with reference to FIGS. 8–12.