U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

John A Clarke

Hugo Johan Cornelissen

Dirk Jan Broer

Neil C Bird

Johannes H Spruit

Leendert Vriens

Cornelis Van Berkel

Horst Greiner

Martinus V Stroomer

David J McCulloch

Harry Howden

Allan Carmichael

Arthur J Jenkins

A back lighting system for illuminating a display device comprises a light-emitting panel () and a light source () for coupling light into the light-emitting panel. The light source comprises a low-pressure discharge lamp (). The light source additionally comprises a plurality of LEDs (', . . . ) for selectively setting the color temperature of the light emitted by the light source. Preferably, the LEDs increase the color temperature of the light emitted by the light source. Preferably, the light emitted by the back lighting system ranges from 6,000 to 10,500 K. Preferably, the LEDs are blue light emitting LEDs, each preferably having a luminous flux of at least 5 lm. The color point of an image to be displayed on a display screen of the display device is set by the back lighting system, thus enabling an optimum contrast to be achieved for the image to be displayed by the display device.

Illumination system and display device

In a laser system for laser crystallization of semiconductor films, a laser source produces a laser beam that is transmitted to a lens system having a plurality of lens elements adapted to divide the beam into a plurality of beamlets. At least one of the beamlets is inverted relative to the others, such that a desired intensity profile is generated at the output of the laser system.

Laser system with mixed polarity beamlets

A display system comprises a substantially flat matrix display panel ( ), for example an LCD, a viewing screen ( ) spaced from the panel and curved in one or more directions, for example to conform with the contour of a support structure ( ), and an image transfer arrangement ( ) comprising at least one microlens array curved in a similar sense to the screen and disposed between the panel and the screen whose individual lens elements transmit respective portions of the image on the panel onto corresponding positions on the screen. The arrangement may comprise imaging, field and re-imaging arrays ( ) in series with corresponding lens elements in the arrays having a common optical axis.

Display system having curved microlens array between flat matrix display panel and similarly curved viewing screen

An image relay arrangement (20) for use with a curved CRT faceplate (11) to relay a picture to a position in front of the faceplate comprises a first, imaging, microlens array (22), a second, field, microlens array (23) and a third, re-imaging, microlens array (24) which are spaced from one another and have corresponding microlens elements (25, 26, 27). At least one of the first and third arrays is curved with its spacing from the adjacent array varying over its area related to the faceplate curvature. Through this arrangement, the picture at the curved faceplate can be imaged onto a plane where, for example, a lenticular screen is located enabling autostereoscopic displays to be produced.

CRT having microlenses with a predetermined relationship with the

An autostereoscopic display apparatus comprises means (10) for producing a display consisting of display pixels (12) in rows and columns, for example, an LC matrix display panel having a row and column array of display elements, and an array (15) of parallel lenticular elements (16) overlying the display, in which the lenticular elements are slanted with respect to the display pixel columns. The reduction in display resolution experienced in such apparatus, particularly in the case of a multi-view type display, is then shared between both horizontal and vertical resolution. Examples of full colour display apparatus using advantageous colour display pixel lay-out schemes are also described.

Autostereoscopic display apparatus

An image sensor 10 includes an array of light responsive pixels 22 and an array 30 of focusing lens elements 32. Each lens element 32 is associated with a plurality of pixels 22, so that the lens elements may be fabricated simply. The array 30 is preferably part of a non-inverting focusing arrangement, and the lens elements 32 are preferably refractive microlens elements.

Image sensor in which each lens element is associated with a plurality

An electrical device comprising an array of pixels has a plurality of panels 10, 20, 30, each having a respective sub-array of pixels 11. Each panel 10, 20, 30 is associated with an array 40 of lens elements 42, which may be associated with a group of one or more pixels of the sub-array. The lens elements 42 are arranged with a pitch which is greater than the pitch of the associated group of pixels, so that a diverging image is produced, enabling tiling of panels of an image sensor or of a display device.

Electrical device comprising an array of pixels

An image sensor comprises an image capturing device 10 and a lens arrangement 20, 30, 40, positioned between an area to be imaged and the image capturing device 10. The lens arrangement includes at least one array 40 of spaced lens elements 42 for transmitting light from a portion of the area to be imaged to a portion of the device 10. Light emitting apparatus 46, for example electroluminescent strips, are disposed in or over the spacing between the lens elements 42. This provides a compact optical focusing and illumination system. A color imaging system may be provided using discrete colored light sources.

Image sensor

A color image projection apparatus comprising a plurality of (LC) image display panels (33), each operating with light of a different color (R,G,B), whose outputs are combined by combining means (24, 25) and projected via a lens (28) onto a screen (32) and electro-optical deflection means, comprising a birefringent element (40) following the combining means and preceded by polarization switch means (42) operable to displace slightly the outputs from rows of pixels in each of the panels in either the odd or even fields so as to produce an interlaced image on the screen. Considerably improved performance is achieved by providing a respective, separate, polarization switch element between each display panel (33) and the combining means (24, 25), and preferably closely adjacent to the output side of the display panel.

Color interlaced image projection apparatus

An image projection apparatus comprises an illumination unit (10), an image display unit (20), comprising a matrix display panel (22) having a row and column array of pixels (25), a projection lens (40) for projecting range produced by the display panel on to a screen (50) and an optical deflection unit (30) arranged between the display unit and the projection lens which is operable selectively to shift the light rays from a row of pixels passing therethrough whereby the pixel row images on the screen in one field are displaced and interlaced with the pixel row images of a preceding field. The image display unit (20) includes an array of lens elements (60) overlying the array of pixels whose effect is to reduce the height of the image of each pixel row in the projected display so the pixel row images of one field can fill the gaps between adjacent pixel row images of a preceding field without any substantial overlap and display panels having high aperture ratio can be utilised.

Interlaced image projection apparatus

In a color liquid crystal projection display in which three differently-colored illuminating beams (R,G,B) are incident from mutually different directions on an LC panel (20) having an array of display elements (40) with a microlens array (21) at the input side of the panel end of whose elements (42) overlies a respective group of three adjacent display elements in row or delta configuration and through each of which light of the three colours (R,G,B) is directed at different angles respectively and converged towards respective ones of the display elements in its associated group, a deflecting element array (25), comprising, for example, microlens element (44) or microprisms (46) formed in a glass substrate of the panel, is positioned close to the plane of the display elements to deflect the directions of light of at least two of the three colours from each microlens element (42) to bring the directions of light of the three colours at the output side of the panel towards a common direction, and preferably substantially parallel to one another. A significant reduction in the amount of spread of light if the output side is thereby achieved, such that, inter alia, a comparatively small aperture projection lens (30) can be used.

Color liquid crystal projection display systems

An image projection apparatus which comprises an illumination unit, an image display unit, a projection lens and an electro-optical deflection unit arranged between the display unit and the projection lens and being switchable between a first mode and a second mode and comprising a polarization switch and a birefringent element, whereby the light rays from the display unit passing through the deflection unit if the deflection unit is in the first mode are shifted relative to said light rays passing through the deflection unit if this unit is in the second mode. The birefringent element comprises at least one birefringent oriented polymer layer.

In a color liquid crystal projection display in which three differently-colored illuminating beams (R,G,B) are incident from mutually different directions on an LC panel (20) having an array of display elements (40) with a microlens array (21) at the input side of the panel comprising microlens elements (42) overlying groups of display elements that direct light from the beams through respective sets of display elements, and a projection lens (30) projects the output beams from the panel onto a screen (31), the beam geometries are selected such that at a position spaced from the output side of the panel the three output beams pass respectively through substantially separate areas and filter means (50) are disposed at that position to remove unwanted color stray light at each area thus improving color purity. Each microlens element of the array directs light from one color beam onto one display element and light from the other two beams onto respective display elements which are not immediately adjacent that one display element.

Liquid crystal projection system having three different color beams pass

A liquid crystal projection display system includes a liquid crystal display panel (7) which is illuminated by light directed at a small angle (A) to its normal for display contrast enhancement. To reduce defocussing and distortion effects, the panel is tilted with the normal to its plane at an angle (B) to the axis of the projection lens smaller than the illumination angle (A) and a deflector element is disposed between the panel and the projection lens for deflecting the panel output beam so that it is directed generally parallel to the projection lens axis. The panel may be operated in a reflective mode or a transmissive mode. In the latter case, a further deflector element may be disposed adjacent the input side of the panel allowing the axis of illuminating light beam to be arranged parallel with the projection lens axis.

Liquid crystal projection display systems

An illumination system is provided for a liquid crystal display panel. The panel 1 is placed to transmit light 2 from a light source 3 to a viewing location, the light source being an extended area source of omnidirectional light of high efficiency, such as a fluorescent tube. A light guide 6 is placed between the source and the panel, the light guide comprising a transparent input face 7 adjacent the source, a transparent output face 10 adjacent the panel, and reflective side walls 11 transverse to the input and output faces. The light guide is tapered, the input face being smaller in area than the output face. The divergence of light from the source is thereby reduced as it passes through the panel. The LCD panel then functions with an improved contrast range.

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Carshalton, United Kingdom

John A Clarke