Projection device and associated electro-optic monochrome display device with phosphor layer and interference filters
First Claim
Patent Images
1. A projection device comprising:
- a projection screen, at least one radiation source;
at least one monochrome display device for operation in the transmission mode, the display device comprising an electro-optical means, two parallel substrates flanking the electro-optical means and provided with drive means to cause the electro-optical means to change its transmission state at least locally and to define a pattern in the electro-optical means; and
projection means for projecting the pattern onto the projection screen;
characterized in that;
the display device is provided with a layer of material luminescing in one colour, which material can be excited by radiation from the radiation source,a first interference filter is arranged between the radiation source and the layer of luminescent material, which filter substantially completely passes radiation suitable for excitation and substantially completely reflects radiation generated in the luminescent material; and
a second interference filter is arranged on the other, viewing side of the layer of luminescent material, which second filter has a high transmission for light of the desired spectral characteristic which is emitted by the luminescent layer at small angles to the normal on the second filter, and in which the reflection considerably increases for light rays of said spectral characteristic which extend at an angle of more than 20°
to 35°
to the normal on the second filter.
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Abstract
A projection device features at least one monochrome display device including electro-optic means defining a pattern for display, a monochrome luminescent layer, a first interference filter for reflecting the luminescent emission forward toward a display screen, and a second interference filter for obtaining a limited transmission angle for the desired spectral output.
102 Citations
38 Claims
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1. A projection device comprising:
- a projection screen, at least one radiation source;
at least one monochrome display device for operation in the transmission mode, the display device comprising an electro-optical means, two parallel substrates flanking the electro-optical means and provided with drive means to cause the electro-optical means to change its transmission state at least locally and to define a pattern in the electro-optical means; and
projection means for projecting the pattern onto the projection screen;characterized in that; the display device is provided with a layer of material luminescing in one colour, which material can be excited by radiation from the radiation source, a first interference filter is arranged between the radiation source and the layer of luminescent material, which filter substantially completely passes radiation suitable for excitation and substantially completely reflects radiation generated in the luminescent material; and a second interference filter is arranged on the other, viewing side of the layer of luminescent material, which second filter has a high transmission for light of the desired spectral characteristic which is emitted by the luminescent layer at small angles to the normal on the second filter, and in which the reflection considerably increases for light rays of said spectral characteristic which extend at an angle of more than 20°
to 35°
to the normal on the second filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- a projection screen, at least one radiation source;
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19. A monochrome display device for use in a projection device, comprising electro-optical means, two parallel substrates flanking the electro-optical means and provided with drive means to cause the electro-optical means to change its state at least locally, characterized in that:
- a layer of monochrome luminescent material is provided on one of the substrates;
a first interference filter is provided adjacent one side of the luminescent layer, which filter substantially completely passes radiation suitable for excitation of the luminescent material and substantially completely reflects radiation generated in the luminescent material; and
a second interference filter is provided adjacent the other side of the luminescent layer, the second filter having a high transmission for light of the desired spectral characteristic which is emitted by the luminescent layer at small angles to the normal on the second filter, and in which the reflection considerably increases for light rays of said spectral characteristic which extend at an angle of more than 20°
to 35°
to the normal on the second filter. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
- a layer of monochrome luminescent material is provided on one of the substrates;
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27. An illumination source comprising a space accommodating a radiation source and bounded by a first flat wall, and a second reflective wall,
characterized in that the first wall is provided with at least one layer of a material luminescing in one colour, which layer can be excited by the radiation source, and in that a first interference filter is arranged between the radiation source and the layer of luminescent material, which filter substantially completely passes radiation suitable for excitation and substantially completely reflects radiation generated in the luminescent material, and in that a second interference filter is arranged on the other side of the layer of luminescent material, which second filter has a high transmission for light of the desired spectral characteristic which is emitted by the luminescent layer at small angles to the normal of the second filter, and in which the reflection considerably increases for light rays of the said spectral characteristic which extend at an angle of more than 20° - to 35°
to the normal on the second filter. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
- to 35°
Specification