Variable reflectivity notch filter and optical devices using same
First Claim
1. An image projection system having a display that is at least partially transmissive and partially reflective, the image projection system comprising:
- a laser projection source having a controller configured to direct laser light to form an image on a display surface; and
a reflective layer integrated with the display surface, wherein the reflective layer comprises a variable reflectivity notch filter defining a transmission curve comprising a plurality of reflective peaks centered about predetermined wavelengths of light, each reflective peak having an associated reflectivity, wherein a reflectivity of at least one peak is different from a reflectivity of at least another peak, wherein the laser projection source comprises a plurality of laser sources each configured to emit light centered at a predetermined wavelength, wherein the predetermined wavelength changes as a function of temperature across a predefined range from a minimum wavelength to a maximum wavelength, wherein the plurality of reflective peaks are configured to at least partially reflect the minimum wavelength and the maximum wavelength.
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Accused Products
Abstract
A variable reflectivity notch filter (100), suitable for use with a laser image projection source (1001) is provided. The variable reflectivity notch filter (100) defines a transmission curve (101) having a plurality of reflective peaks (102,103,104) each centered about a predetermined wavelength (105,106,107), which can correspond to output wavelengths from laser sources. Reflective peaks (204) corresponding to wavelengths that change with temperature are configured with wider widths (223) and lesser reflectivities (210) than are other reflective peaks (202,203). To provide enhanced color balance, lasers (821) corresponding to these reflective peaks (204) can be driven at higher output power. Variable reflectivity notch filters (100) are suitable for use in head-up displays as well as other applications.
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Citations
6 Claims
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1. An image projection system having a display that is at least partially transmissive and partially reflective, the image projection system comprising:
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a laser projection source having a controller configured to direct laser light to form an image on a display surface; and a reflective layer integrated with the display surface, wherein the reflective layer comprises a variable reflectivity notch filter defining a transmission curve comprising a plurality of reflective peaks centered about predetermined wavelengths of light, each reflective peak having an associated reflectivity, wherein a reflectivity of at least one peak is different from a reflectivity of at least another peak, wherein the laser projection source comprises a plurality of laser sources each configured to emit light centered at a predetermined wavelength, wherein the predetermined wavelength changes as a function of temperature across a predefined range from a minimum wavelength to a maximum wavelength, wherein the plurality of reflective peaks are configured to at least partially reflect the minimum wavelength and the maximum wavelength. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification