US5440352A — Laser-driven television projection system with at…

Claim 1

Independent Claim 262 words

In a process for generating color picture points of a television picture which are illuminated with light signals (R L ', G L ', B L ') of different wavelengths and whose hues are fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined by way of wavelengths of screen phosphors, in which process a second base system is derived in which the wavelengths of the light signals (RL', GL', BL') differ from those of the first base system and which shares a common range of hues with the first base system, and in which process light signals are generated from at least three signals (K, L, M) which are the color value signals (R, G, B) or contain said color value signals by way of a transformation from said first base system into said second base system using a matrix, the improvement comprising the steps of: determining the wavelengths of the light signals (RL', GL', BL') so that the shortest is 470 nm or less and so that the common range of hues contains at least those corner points of the range of hues of the first base system whose wavelength is greater than the shortest wavelength determined by screen phosphors; and assuring that every hue produced by the matrix transformation within the common range of hues in the second base system is identical to the hue determined by the color value signals in the first base system.

Claim 2

Dependent Claim 262 words

In a process for generating color picture points of a television picture which are illuminated with light signals (R L ', G L ', B L ') of different wavelengths and whose hues are fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined by way of wavelengths of screen phosphors, in which process a second base system is derived in which the wavelengths of the light signals (RL', GL', BL') differ from those of the first base system and which shares a common range of hues with the first base system, and in which process light signals are generated from at least three signals (K, L, M) which are the color value signals (R, G, B) or contain said color value signals by way of a transformation from said first base system into said second base system using a matrix, the improvement comprising the steps of: determining the wavelengths of the light signals (RL', GL', BL') so that the shortest is 470 nm or less and so that the common range of hues contains at least those corner points of the range of hues of the first base system whose wavelength is greater than the shortest wavelength determined by screen phosphors; and assuring that every hue produced by the matrix transformation within the common range of hues in the second base system is identical to the hue determined by the color value signals in the first base system.

Claim 3

Dependent Claim 51 words

The process according to claim 1, wherein, for negative intensities resulting from the matrix transformation for color signals of hues outside the common range of hues, the process includes the step of producing light signals with an intensity achieved from the respective negative intensity via a logarithmic asymptotic function approaching zero.

Claim 4

Dependent Claim 296 words

In a television projection system for generating color picture points of a television picture using at least three light sources which may be controlled in intensity for developing light signals (R L ', G L ', B L ') of different wavelengths, wherein the hue of each picture point is fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined via wavelengths of screen phosphors, and wherein the wavelengths of the light signals (R L ', G L ', B L ') determine a second base system which differs from the first base system and which shares a common range of hues with the first base system, having an input circuit for generating at least three electric signals (K, L, M) which are proportional to the color value signals or contain a mixture thereof, having a control device for controlling said light sources, said control device capable of being triggered by the signals (K, L, M) of the input circuit and having a transformation circuit for transforming every hue from the first base system into the second base system via a matrix, the improvement comprising: that the shortest wavelength of said light sources is 470 nm or less, the other wavelengths of said light sources being such that the common range of hues contains at least those corner points of the range of hues of the first base system whose wavelength is greater than the shortest wavelength determined by screen phosphors, and said transformation circuit includes means for assuring that the hue of a picture point within the common range of hues is identical to the hue determined by the color value signals.

Claim 5

Dependent Claim 296 words

In a television projection system for generating color picture points of a television picture using at least three light sources which may be controlled in intensity for developing light signals (R L ', G L ', B L ') of different wavelengths, wherein the hue of each picture point is fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined via wavelengths of screen phosphors, and wherein the wavelengths of the light signals (R L ', G L ', B L ') determine a second base system which differs from the first base system and which shares a common range of hues with the first base system, having an input circuit for generating at least three electric signals (K, L, M) which are proportional to the color value signals or contain a mixture thereof, having a control device for controlling said light sources, said control device capable of being triggered by the signals (K, L, M) of the input circuit and having a transformation circuit for transforming every hue from the first base system into the second base system via a matrix, the improvement comprising: that the shortest wavelength of said light sources is 470 nm or less, the other wavelengths of said light sources being such that the common range of hues contains at least those corner points of the range of hues of the first base system whose wavelength is greater than the shortest wavelength determined by screen phosphors, and said transformation circuit includes means for assuring that the hue of a picture point within the common range of hues is identical to the hue determined by the color value signals.

Claim 6

Dependent Claim 42 words

The television projection system according to claim 3, wherein the electric signals of the input circuit include a luminance signal which is proportional to the sum of the three color value signals and two different signals proportional to the color difference signals.

Claim 7

Dependent Claim 22 words

The television projection system according to claim 3, wherein said transformation circuit includes a network of resistors for determining the matrix transformation.

Claim 8

Dependent Claim 49 words

The television projection system according to claim 5, wherein said transformation circuit includes an operational amplifier for each of its output signals, said operational amplifier forming the sum of the current generated by electric signals (K, L, M) and passing through said network of resistors determining the matrix transformation.

Claim 9

Dependent Claim 25 words

The television projection system according to claim 6, wherein said network of input resistors is arranged so as to be exchangeable in said transformation circuit.

Claim 10

Dependent Claim 36 words

The television projection system according to claim 3, wherein said light sources are lasers having light modulators, and wherein the light intensity of the light sources can be varied by electrical control of the light modulators.

Claim 11

Dependent Claim 15 words

The television projection system according to claim 3, wherein said light sources are semiconductor lasers.

Claim 12

Dependent Claim 14 words

The television projection system according to claim 3, wherein said light sources are LEDs.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-08-07	1999-02-06	1999-08-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-08-07	2003-02-06	2003-08-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-08-07	2007-02-06	2007-08-08	$7700.00	Window Closed / Lapsed

Laser-driven television projection system with attendant color correction

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag