Apparatus and Method for Interpolating the Intensities of Scanned Pixels from Source Pixels

Abstract

A scan assembly of an image generator sweeps an image beam in a first dimension at a first rate and bi-directionally in a second dimension at a slower rate. Sweeping the beam bi-directionally in the vertical dimension (generally the dimension of the lower sweep rate) can reduce the scanning power by eliminating the flyback period, and, where the scan assembly includes a mechanical reflector, can reduce the error in the beam position without a feedback loop by reducing the number of harmonics in the vertical sweep function. Furthermore, because the image beam is “on” longer due to the elimination of the flyback period, the scanned image is often brighter for a given beam intensity. The scan assembly may also sweep the image beam non-linearly in the vertical dimension, and this sweep may be bi-directional or uni-directional. Sweeping the beam non-linearly can also reduce the error in the beam position by reducing the number of harmonics in the vertical sweep function.

Description

CLAIM OF PRIORITY[0001]This application claims priority to U.S. Provisional Application Ser. No. 60 / 381,569, filed on May 17, 2002, which is incorporated by reference.BACKGROUND[0002]An electronic image generator, such as television set, scans a viewable image, or a sequence of viewable video images, onto a display screen by electronically sweeping an electromagnetic image beam across the screen. For example, in a television set, the image beam is a beam of electrons, and a coil generates a linearly increasing magnetic field or electric field to sweep the beam.[0003]An optical image generator is similar except that it scans a viewable image onto a display screen by mechanically sweeping an electromagnetic image beam across the screen. Or, in the case of a Virtual Retinal Display (VRD), the optical image generator scans a viewable directly onto a viewer's retina(s).[0004]FIG. 1 is a view of a conventional optical image-display system 10, which includes an optical image generator 12 a...

AI Technical Summary

Benefits of technology

[0015]For example, sweeping the beam bi-directionally in the vertical dimension can reduce the scanning power by eliminating the flyback period, and can reduce error in the beam position without a feedback loop by reducing the number of harmonics in the vertical sweep function. Furthermore, because the image beam is “on” longer due to the elimination of the flyback period, the scanned image is often brighter for a given beam intensity, thus allowing one to proportionally reduce the intensity, and thus the power, of the image beam for a given image brightness.

[0017]For example, sweeping the beam non-linearly in the vertical dimension can also reduce the error in the beam position by reducing the number of harmonics in the vertical sweep function.

Problems solved by technology

Unfortunately, uni-directionally sweeping the beam 18 in the vertical (Y) dimension may increase the cost, complexity, size, and power consumption of the system 10.

Unfortunately, such a feedback loop often includes complex circuitry that can occupy significant layout area, and, thus, may increase the complexity, size, and cost of the image generator 12.

Unfortunately, this may increase the power consumed by the image generator 12 and the size of the scan assembly's current-driver circuit (not shown), and thus may further increase the cost of the image generator.

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