Apparatus for generating high contrast optical signals, and exemplary applications
First Claim
1. An optical signaling apparatus, comprising:
- a controllable first source of illumination capable of providing ON and OFF illumination states; and
an optical medium arranged to receive illumination from said controllable first source and capable of receiving illumination from a second source, wherein a region of said medium is arranged in such a way that a detectable optical signal is visible therefrom during an illumination ON state of said controllable first source, and wherein said region of said medium is essentially indistinguishable from other parts of the medium during an OFF illumination state of said controllable first source, notwithstanding the arrangement of said region,wherein said region of said optical medium comprises microscopic features formed in said medium, said microscopic features having a size in the range from about 0.5 μ
m to about 100 μ
m, said microscopic features being substantially absent of any melted or oxidized region therealong, to increase the visibility of the optical signal in said ON-state, and wherein said microscopic features are formed with ultrashort laser pulses.
1 Assignment
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Accused Products
Abstract
A display apparatus generates a high visibility optical signal, such as an ICON, the ICON comprising a symbol, shape, or other image-like representation. The ICON becomes visible at an observation point during an illumination ON-state. The ICON may be formed as a portion of display medium, for example as a machined portion of a mirror capable of forming images of a scene by reflection in normal operation. The visibility of the ICON in the illumination OFF-state from an observation point is sufficiently low such that the normal operation of the display medium is maintained. The display apparatus may be used in a blind spot warning system for a vehicle. Visible wavelength LEDs, RGB LEDs and/or diode lasers may be utilized as an illumination source. Ultrashort laser processing or other methods for material modification may be utilized to form microscopic features which distribute incident light, increasing the visibility of the optical signal at an observation point in an ON-state, with very low visibility in the OFF-state and minimal effect on the image in the display medium in the OFF state.
41 Citations
32 Claims
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1. An optical signaling apparatus, comprising:
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a controllable first source of illumination capable of providing ON and OFF illumination states; and an optical medium arranged to receive illumination from said controllable first source and capable of receiving illumination from a second source, wherein a region of said medium is arranged in such a way that a detectable optical signal is visible therefrom during an illumination ON state of said controllable first source, and wherein said region of said medium is essentially indistinguishable from other parts of the medium during an OFF illumination state of said controllable first source, notwithstanding the arrangement of said region, wherein said region of said optical medium comprises microscopic features formed in said medium, said microscopic features having a size in the range from about 0.5 μ
m to about 100 μ
m, said microscopic features being substantially absent of any melted or oxidized region therealong, to increase the visibility of the optical signal in said ON-state, and wherein said microscopic features are formed with ultrashort laser pulses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 16, 17, 18, 19, 20, 24, 27, 30)
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11. An optical signaling method, comprising:
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controlling a first source of illumination capable of providing ON and OFF illumination states; and utilizing an optical medium arranged with microscopic features formed therein to receive illumination from said first source and to receive illumination from a second source, said microscopic features having a size in the range from about 0.5 μ
m to about 100 μ
m,wherein a region of said medium is arranged in such a way that a detectable optical signal is visible therefrom during an illumination ON state of said first source, and wherein said region of said medium is essentially indistinguishable from other parts of the medium during an OFF illumination state of said first source, notwithstanding the arrangement of said region, said microscopic features being substantially absent of any melted or oxidized region therealong, to increase the visibility of the optical signal in said ON-state, and wherein said microscopic features are formed with ultrashort laser pulses. - View Dependent Claims (12, 26, 29, 32)
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13. A visual warning system, comprising:
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a controllable first source of illumination capable of providing ON and OFF illumination states; and an optical medium arranged to receive illumination from said controllable first source and capable of receiving illumination from a second source different than the first source, wherein a region of said optical medium comprises microscopic features that distribute energy from said controllable first source over a viewing angle so as to form an optical signal visible therefrom during an illumination ON state of said controllable first source, wherein said visible optical signal is in the form of an ICON comprising a symbol, shape, or other image-like representation, and wherein said region of said optical medium is essentially indistinguishable from other parts of the optical medium during an OFF illumination state of said controllable first source, notwithstanding the arrangement of said region of microscopic features, wherein said region of said optical medium forms a portion of a visible image obtainable with said illumination from said second source, wherein said optical medium comprises a transparent or translucent substrate and a reflective coating disposed thereon, wherein said region of said optical medium comprises said microscopic features formed in said medium by selective removal of a depth-wise portion of the reflective coating, said microscopic features having a size in the range from about 0.5 μ
m to about 100 μ
m, said microscopic features being substantially absent of any melted or oxidized region therealong, and having a small laser induced heat-affected zone, to increase the visibility of the optical signal in said ON-state, and wherein said microscopic features are formed with ultrashort laser pulses. - View Dependent Claims (14, 21, 22, 23, 25, 28, 31)
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Specification