US5828424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for generating at least three laser beams of different wavelength for the display of color video pictures
Assignee: LDT Laser Display Technology GmbH
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Filing: 1995-09-06
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Granted: 1998-10-27
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Expires: 2015-09-06
Abstract
Abstract PCT No. PCT/EP95/03501 Sec. 371 Date Jul. 5, 1996 Sec. 102(e) Date Jul. 5, 1996 PCT Filed Sep. 6, 1995 PCT Pub. No. WO96/08116 PCT Pub. Date Mar. 14, 1996In a process for generating at least three laser beams of different wavelengths for displaying color video pictures, a pulsed laser is used to generate light. The light output of the pulsed laser is released in a pulse and is introduced into a medium with nonlinear optical characteristics for generating a laser beam. In addition to the laser beam generated by excitation, this medium releases an additional laser beam whose frequency is given by the sum or difference frequencies of the exciting laser beam and the excited laser beam due to the nonlinear optical characteristics of the medium. The laser beams generated by the medium in this way and the exciting laser beam are used directly, or after frequency conversion, to display monochromatic partial images of a color video picture. An apparatus according to the invention contains suitable devices for carrying out the process.
Inventors
- 👤 Richard Wallenstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:43
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3129; G; G02; G02F; G02F1/00; G02F1/35; G02F1/353; G02F1/3532
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
231 words
In a process for generating at least three laser beams of different wavelengths for displaying color video pictures in which every laser beam is controlled in intensity for generating a monochromatic partial image, and these monochromatic partial images are mixed additively for displaying the color video pictures, wherein at least one of the three laser beams is obtained in that a medium is excited by at least a partial beam of an exciting primary laser with a defined wavelength, which the medium, upon excitation, emits an excited laser beam with a different wavelength than the wavelength of the exciting primary laser, and wherein the exciting primary laser beam and the excited laser beam are used directly or after frequency conversion for the display of monochromatic partial images, the improvement comprising the steps of: using a pulsed laser as the exciting primary laser; using the material with nonlinear optical characteristics as a medium, wherein the material, in addition to the excited laser beam generated by excitation, releases an additional laser beam whose frequency is given by the sum or difference frequencies of the exciting primary laser beam and the excited laser beam; and using the laser beams emitted by the medium and the exciting primary laser beam directly as laser beams for the display of monochromatic partial images or converting them into the laser beams for the display of monochromatic partial images.
Claim 2
Dependent Claim
231 words
In a process for generating at least three laser beams of different wavelengths for displaying color video pictures in which every laser beam is controlled in intensity for generating a monochromatic partial image, and these monochromatic partial images are mixed additively for displaying the color video pictures, wherein at least one of the three laser beams is obtained in that a medium is excited by at least a partial beam of an exciting primary laser with a defined wavelength, which the medium, upon excitation, emits an excited laser beam with a different wavelength than the wavelength of the exciting primary laser, and wherein the exciting primary laser beam and the excited laser beam are used directly or after frequency conversion for the display of monochromatic partial images, the improvement comprising the steps of: using a pulsed laser as the exciting primary laser; using the material with nonlinear optical characteristics as a medium, wherein the material, in addition to the excited laser beam generated by excitation, releases an additional laser beam whose frequency is given by the sum or difference frequencies of the exciting primary laser beam and the excited laser beam; and using the laser beams emitted by the medium and the exciting primary laser beam directly as laser beams for the display of monochromatic partial images or converting them into the laser beams for the display of monochromatic partial images.
Claim 3
Dependent Claim
22 words
The process according to claim 1, wherein the exciting primary laser is pulsed at a pulse duration of less than 100 ps.
Claim 4
Dependent Claim
129 words
The process according to claim 1, including the step of selecting the exciting primary laser, with respect to its wavelength, and the medium so that when assigning the colors red, green and blue to the wavelengths of the three laser beams which are generated for displaying the monochromatic partial images, the wavelength of the generated blue laser beam is between 400 nm and 470 nm, the wavelength of the generated green laser beam lies in the range of 520 nm to 540 nm, and the wavelength of the generated red laser beam is less than 635 nm, wherein the outputs of the laser beams over the pulse duration with the colors red and blue do not deviate by more than 30% from the output of the green laser beam.
Claim 5
Dependent Claim
27 words
The process according to claim 1, wherein excitation is effected via the fundamental frequency or an upper harmonic of a mode-coupled Nd:YLF laser or Nd:YVO 4 laser.
Claim 6
Dependent Claim
61 words
The process according to claim 1, further comprising the steps of selecting the material for the medium, positioning the medium and mirrors, and phase-matched coupling in of the exciting primary laser beam and the excited laser beam, the steps of selecting the material, positioning and phase-matched coupling being effected so as to result in the design of an optical parametric oscillator.
Claim 7
Dependent Claim
14 words
The process according to claim 1, wherein the temperature of the medium is regulated.
Claim 8
Dependent Claim
22 words
The process according to claim 6, wherein the wavelength of the excited laser beam is adjusted via the temperature of the medium.
Claim 9
Dependent Claim
34 words
The process according to claim 1, wherein the exciting laser beam and/or the laser beams generated in the medium by the exciting laser beam are frequency-multiplied or frequency-summed with another laser beam for conversion.
Claim 10
Dependent Claim
39 words
The process according to claim 1, wherein the pulse duration of the exciting primary laser beam is so adjusted that the generated wavelength spectrum in the excited laser beam cancels out interference of the excited laser beam with itself.
Claim 11
Dependent Claim
53 words
The process according to claim 9, wherein the monochromatic partial images are generated by sequential rastering of the image as image points at a predetermined image point frequency and the pulses of the exciting primary laser beam are repeated at a repetition frequency which is an integral multiple of the image point frequency.
Claim 12
Independent Claim
162 words
An apparatus for generating at least three laser beams of different wavelengths for the display of color video pictures, comprising: a control device for controlling three laser beams for generating monochromatic partial images which are mixed additively for displaying a color video picture; a primary laser for producing an exciting laser beam; and a medium excitable by the primary laser to produce an excited laser beam, wherein the exciting laser beam and the excited laser beam are used directly or after frequency conversion for displaying monochromatic partial images; said primary laser being operated in a pulsed manner so that its light output is released in a pulse; and said medium being a material with nonlinear optical characteristics which, in addition to the laser beam excited by the exciting laser beam, also releases another laser beam whose frequency is given by the nonlinear optical characteristics of the material as a sum or difference frequency of the exciting laser beam and excited laser beam.
Claim 13
Independent Claim
162 words
An apparatus for generating at least three laser beams of different wavelengths for the display of color video pictures, comprising: a control device for controlling three laser beams for generating monochromatic partial images which are mixed additively for displaying a color video picture; a primary laser for producing an exciting laser beam; and a medium excitable by the primary laser to produce an excited laser beam, wherein the exciting laser beam and the excited laser beam are used directly or after frequency conversion for displaying monochromatic partial images; said primary laser being operated in a pulsed manner so that its light output is released in a pulse; and said medium being a material with nonlinear optical characteristics which, in addition to the laser beam excited by the exciting laser beam, also releases another laser beam whose frequency is given by the nonlinear optical characteristics of the material as a sum or difference frequency of the exciting laser beam and excited laser beam.
Claim 14
Dependent Claim
57 words
The apparatus according to claim 11, wherein mirrors are provided for the phase-matched coupling in of the exciting laser beam and the excited laser beam relative to the medium, the medium is a nonlinear optical crystal, and the crystal and mirrors are arranged, with reference to the primary laser, in the manner of an optical parametric oscillator.
Claim 15
Dependent Claim
19 words
The apparatus according to claim 11, wherein a regulating device is provided for regulating the temperature of the medium.
Claim 16
Dependent Claim
38 words
The apparatus according to claim 13, wherein the regulating device is adjustable with respect to the temperature to be regulated and the wavelength of the laser beam which is excited by the medium is not dependent upon temperature.
Claim 17
Dependent Claim
25 words
The apparatus according to claim 11, wherein frequency multipliers or sum frequency mixers are provided for converting the exciting laser beam and excited laser beam.
Claim 18
Dependent Claim
56 words
The apparatus according to claim 11, wherein a deflection device is provided for generating the monochromatic partial images in an image point raster with an image point frequency and a pulse device is provided for the primary laser which pulses the laser at a repetition frequency which is an integral multiple of the image point frequency.
Claim 19
Dependent Claim
28 words
The apparatus according to claim 11, wherein a self-modulating optical medium is provided in at least one of the light paths of one of the three laser beams.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-10-26 | 2002-04-27 | 2002-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-26 | 2006-04-27 | 2006-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-26 | 2010-04-27 | 2010-10-27 | $7700.00 | Window Closed / Lapsed |