USRE42428E1 - Method of and device for generating an image having a desired brightness - Google Patents

Method of and device for generating an image having a desired brightness Download PDF

Info

Publication number
USRE42428E1
USRE42428E1 US11818539 US81853907A USRE42428E US RE42428 E1 USRE42428 E1 US RE42428E1 US 11818539 US11818539 US 11818539 US 81853907 A US81853907 A US 81853907A US RE42428 E USRE42428 E US RE42428E
Authority
US
Grant status
Grant
Patent type
Prior art keywords
image
desired
brightness
light
light source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US11818539
Inventor
Douglas A. Stanton
Martinus V. C. Stroomer
Adrianus J. S. M. De Vaan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00Details of colour television systems
    • H04N9/12Picture reproducers
    • H04N9/31Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3102Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
    • H04N9/3105Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00Details of colour television systems
    • H04N9/12Picture reproducers
    • H04N9/31Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3102Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
    • H04N9/3111Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00Details of colour television systems
    • H04N9/12Picture reproducers
    • H04N9/31Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3102Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
    • H04N9/312Driving therefor
    • H04N9/3126Driving therefor for spatial light modulators in series
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00Details of colour television systems
    • H04N9/12Picture reproducers
    • H04N9/31Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3141Constructional details thereof
    • H04N9/315Modulator illumination systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00Details of colour television systems
    • H04N9/12Picture reproducers
    • H04N9/31Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3141Constructional details thereof
    • H04N9/315Modulator illumination systems
    • H04N9/3155Modulator illumination systems for controlling the light source

Abstract

The present invention relates to a method of generating an image having a desired brightness, which image is generated by means of a device provided with at least one light source, at least one electro-optical light modulation panel and at least one light-control device. The light from the light source is converted into an image having a desired brightness via at least the electro-optical light modulation panel and the light-control device. The image to be projected is analyzed in a regulator, whereafter the electro-optical light modulation panel and the light-control device are driven, while a too bright image is generated by means of the electro-optical light modulation panel, which image is converted by means of the light-control device into an image having a desired brightness and a desired contrast.

Description

This is a continuation of Ser. No. 09/389,177 filed on Sep. 2, 1999, now U.S. Pat. No. 6,631,995.

The invention relates to a method of generating an image having a desired brightness, which image is generated by means of a device comprising at least one light source, at least one electro-optical light modulation panel and at least one light-control device, the light from the light source being converted into an image having a desired brightness via at least the electro-optical light modulation panel and the light-control device.

The invention also relates to a device which is suitable for generating an image having a desired brightness by means of such a method, which device comprises at least one light source, at least one electro-optical light modulation panel and at least one light-control device.

In such a method and device known from U.S. Pat. No. 5,597,223, the light-control device comprises a diaphragm having an adjustable aperture. The device is applicable in a light or a dark ambience, with the aperture size being adjusted in dependence upon a light or a dark ambience, such that bright images or images which are rich in contrast are accentuated.

However, the aperture size is not optimized for each image. When, for example, an LCD is used as an electro-optical light modulation panel, the contrast in an image is directly dependent on the desired brightness of this image. When an image to be projected has a relatively low brightness, the LCD is driven accordingly. At a desired, relatively low brightness, the realized contrast is relatively low due to physical properties of the LCD. Consequently, the contrast that can be maximally realized with the LCD cannot be achieved at a desired, relatively low brightness.

It is an object of the invention to provide a method and a device with which a desired brightness and a desired contrast can be realized for each image.

In the method according to the invention, this object is achieved in that the image to be projected is analyzed in a regulator, whereafter the electro-optical light modulation panel and the light-control device are driven, and a too bright image is generated by means of the electro-optical light modulation panel, which image is converted by means of the light-control device into an image having a desired brightness and a desired contrast.

By analyzing preferably each image prior to driving the electro-optical light modulation panel, the light modulation panel can be subsequently driven in such a way that a too bright image having a desired contrast is generated by means of this panel. Simultaneously, the light-control device, which comprises, for example, a diaphragm or a light modulation panel, is driven in such a way that the image generated by means of the light modulation panel and the light-control device has both the desired contrast and the desired brightness.

In the device according to the invention, the object is achieved in that the device comprises a regulator for analyzing the image to be projected, driving the electro-optical light modulation panel for generating a too bright image, and driving the light-control device for converting the too bright image into an image having a desired brightness and a desired contrast.

By driving the light modulation panel as maximally as possible, a maximal brightness and thus a maximal contrast is obtained. The brightness is reduced to the desired level by means of the light-control device.

For an image having large dark areas and large highlights areas, the dark areas can be made perceptually darker by generating a too dark image by the panel, and converting the image into one having the desired brightness and contrast by using the light control device to increase light from the light source.

An embodiment of the device according to the invention is characterized in that the device comprises at least two electro-optical light modulation panels and one light-control device, by means of which images generated on the light modulation panels are simultaneously convertible.

Each light modulation panel is applicable for a different color of the images to be projected. Since each light modulation panel is associated with a light-control device, the light modulation panel can be optimally driven separately for each color by means of the regulator.

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

In the drawings,

FIG. 1 shows a first embodiment of a device according to the invention,

FIG. 2 shows a second embodiment of a device according to the invention,

FIG. 3 shows a third embodiment of a device according to the invention, and

FIG. 4 shows a fourth embodiment of a device according to the invention comprising one color single light modulation panel of the reflective type.

Corresponding components in the Figures are denoted by the same reference numerals.

FIG. 1 shows a device 1 according to the invention, comprising a light source 2, three electro-optical light modulation panels 3, 4, 5 with which a green G, a red R and a blue B part, respectively, of an image to be projected is realized, and a light-control device 6 arranged between the light source 2 and the light modulation panels 3-5. A folding mirror 7 and a PBS 8 (Polarizing Beam Splitter) are arranged between the light source 2 and the light-control device 6. The light-control device 6 may be a diaphragm, but in the embodiment shown here, the light-control device is provided with a twisted nematic cell having a polarizer at an exit side. Lenses 9, (dichroic) folding mirrors 10 and polarization filters 11 are arranged between the light-control device 6 and the light modulation panels 3-5. The lenses 9, (dichroic) folding mirrors 10 and filters 11 are known per se and will therefore not be described in greater detail. The device 1 further comprises a projection lens 12. Filters 11 and (dichroic) folding mirrors 10 are also arranged between the light modulation panels 3-5 and the projection lens 12.

The device 1 further comprises a regulator 13. The regulator 13 has a video signal input 14 which is connected to a video signal analyzer 15 and to a video signal amplifier 16. The video signal analyzer 15 is also connected to the video signal amplifier 16. The video signal amplifier 16 has a video signal line 17 which is also connected to the light modulation panels 3-5. The regulator 13 further comprises a drive module 18 which is arranged between the video signal analyzer 15 and the light-control device 6.

The operation of the device 1 will now be briefly elucidated. The video signal input 14 supplies the information about the images to be projected to the regulator 13. This information is analyzed in the video signal analyzer 15, determining the desired brightness and the desired contrast of the complete image or of parts of the image. Subsequently, the video signal analyzer 15 drives the video signal amplifier 16 and the drive module 18 which in their turn drive the light modulation panels 3-5 and the light-control device 6, respectively.

The video signal amplifier 16 drives the light modulation panels 3-5 in such a way that, in the absence of the light-control device 6, an image would be obtained which would have a too high brightness. However, the contrast of such an image would have a desired value. The drive module 18 drives the light-control device 6 completely or for each part of the image to be projected, such that the brightness of the projected image corresponds to the desired brightness. The regulator 13 is preferably based on statistic information relating to the amplitude range of the video signal.

FIG. 2 shows a device 20 according to the invention, comprising a light source 2, light modulation panels 3-5 and a projection lens 12. The device 20 further comprises lenses 9, (dichroic) folding mirrors 10, a PCS 21 and an integrator 22, arranged between the light source 2 and the light modulation panels 3-5. The device 20 further comprises a dichroic prism 23 arranged between the light modulation panels 3-5 and the projection lens 12. Moreover, the device 20 comprises three light-control devices 24 arranged on a side of the light modulation panels 3-5 remote from the prism 23. The light-control devices 24 and the light modulation panels 3-5 can be driven by means of a regulator, such that, per color green G, red R and blue B, the associated light modulation panel 3-5 is driven in such a way that a too bright image having a desired contrast is obtained, which image is converted by means of the associated light-control devices 24 into an image having a desired brightness.

FIG. 3 shows a third embodiment of a device 30 according to the invention, comprising a light source 2, reflective light modulation panels 3-5 and a projection lens 12. The device further comprises lenses 9, (dichroic) folding mirrors 10, a PCS 21, an integrator 22 and polarizing beam splitters 31, arranged between the light source 2 and the light modulation panels 3-5. The polarizing beam splitters 31 and the dichroic prism 23 are arranged between the light modulation panels 3-5 and the projection lens 12. The device 30 further comprises a liquid-crystal shutter 32 which can be controlled separately for each of the three colors and is arranged on a side of the projection lens 12 remote from the light modulation panels 3-5. Also in the device 30 shown in this embodiment, the light modulation panels 3-5 are driven at a brightness which is relatively too high, whereafter the desired brightness of the image to be projected is generated per color by means of the shutter 32 operating as a light-control device.

Although not mentioned in the description of FIGS. 1 and 2, both embodiments may be provided with an integrator arranged between the light source 2 and the PBS 8.

It is alternatively possible to use the method and the device in systems which are not provided with a projection lens 12.

Dependent on the desired quality of the images to be projected, the light-control device can influence the brightness of the image in its totality, or it can influence the brightness of parts of the image to be projected. As smaller parts of the image can be influenced by the light-control device, a higher quality of the image to be projected can be realized.

It is alternatively possible to provide a light source drive unit as a light-control device, by means of which the brightness of the light source can be controlled per image. Light sources which do not require a constant power level are, for example, Xenon arc lamps and LEDs.

All embodiments described up to now show a device comprising three light valves 3-5. However, it is possible to have a device comprising only one light modulation panel, monochrome or color. A color single light modulation panel can for example by illuminated color sequentially by means of a color wheel, by scrolling bars or by means of three differently colored lamps. In case of a color wheel or three different light sources, the image can be influenced for each color independently. Namely, the segments in the color wheel or the time that each of the lamps is lit can be varied for each color. In case of scrolling bars, it is more difficult to influence the intensity of the colors in the image independently as the panel is illuminated by two bars simultaneously.

When the device comprises three light modulation panels and one light source, independent control of the intensity of the colors in the image is not possible. When the intensity of the light source is changed, the three colors will be influenced simultaneously.

Another embodiment in which independent control for each color is possible is shown in FIG. 4.

FIG. 4 shows an embodiment of a device 40 according to the invention comprising one single light modulation panel 42 of the reflective type. Said panel can be for example a reflective LCD-panel or a DMD-panel. Image information to be projected is provided from a video source 44 via projector electronics 46 to the panel 42, on the one hand, and to a light source controlling device 48, on the other hand, for synchronization. The light source comprises three different lamps 50, 52 and 54, one for each primary color. The light source controlling device 48 is connected to a programmable power supply 56, 58, 60 for the lamps 50, 52 and 54. Via lenses 62 and a prism illuminator 64, the light from the light source is incident on the light valve 42. The prism illumination 42 may be a PBS in case the light valve is an LCD panel and may be a prism based on TIR in case the light valve is a DMD. After modulation by the light valve 42, the light to be projected reaches the projection lens 68. By flashing each of the lamps in a time interval of, for example 16 ms, as is indicated in the inset, and by varying the time interval for the individual lamps, the colors can be varied independently in the image to be projected. The video data to be projected for each color are field sequentially provided to the light modulation panel.

Claims (18)

1. A method of generating a desired image, comprising:
analyzing a first image to determine a desired brightness and a desired contrast for said first image;
providing an illumination beam from a constant intensity light source;
modulating said illumination beam to produce an image beam having said desired contrast; and
optically adjusting a one of said illumination beam and said image beam to form said desired image having said desired brightness.
2. The method as claimed in claim 1, wherein the analyzing is performed by a regulator.
3. The method as claimed in claim 1, wherein the step of modulating is performed by a light modulator panel.
4. The method as claimed in claim 1, wherein the step of optically adjusting is performed by a light control device.
5. The method as claimed in claim 1, wherein a brightness and a contrast of said desired image are adjusted substantially independently of each other.
6. The method as claimed in claim 1, wherein a contrast of said desired image is independent from a background illumination level.
7. The method of claim 1, wherein
the first image does not cover a complete range of gray levels producible by an image processing apparatus performing said step of modulating;
the image beam covers a larger range of gray levels than the first image, while being within said complete range; and
whereby, the desired image has the larger range of gray levels with the desired brightness.
8. The method of claim 7, wherein the image processing apparatus comprises at least one light modulation panel and wherein the image beam comprises image modulation information within the at least one modulation panel.
9. The method of claim 7, wherein the step of modulating results in a brightness level that causes the image beam to lie within parameters achieving a maximum dynamic range of at least a portion of the image processing apparatus.
10. The method of claim 9, wherein the step of optically adjusting relates to a second portion of the image proceasing apparatus.
11. A method for producing an output image in a device comprising a constant intensity light source and at least one light modulator, the output image resulting from passing light from the constant intensity light source through the light modulator, the method comprising:
analyzing an input image to derive a desired contrast and desired brightness;
adjusting the light modulator to a setting which would normally not result in the desired brightness, but would result in the desired contrast;
optically adjusting the brightness of the output image to retain the desired contrast achieved by the light modulator while attaining the desired brightness.
12. An image producing device for generating an output image, the image producing device comprising:
a video input;
at least one constant intensity light source, having a given normal brightness value;
at least one light modulator, responsive to the video input for adding image data from the video input to light from the light source; means for
a video signal analyzer performing video signal processing including:
analyzing the video input to derive a desired contrast and a desired brightness;
supplying at least one first control signal to cause the light modulator to be adjusted to achieve the desired contrast, but a brightness other than the desired brightness with the constant intensity light source at the given normal brightness value; and
supplying at least one second control signal to cause an optical a brightness adjustment optically or by varying a time interval of flashing of the at least one constant intensity light source in order to achieve the desired brightness in the output image in view of the adjustment of the light modulator; so such that the output image has both the desired contrast and the desired brightness.
13. The image producing device of claim 12, further comprising: a light source controlling device, the video signal analyzer supplying the at least one second control signal to cause the light source controlling device to vary a time interval of flashing of the at least one constant intensity light source.
14. The image producing device of claim 12, wherein the output image is an output color image, and the at least one constant intensity light source comprises:
a red constant intensity light source, having a normal red brightness value;
a green constant intensity light source having a normal green brightness value; and
a blue constant intensity light source having a normal blue brightness value, wherein the adjusting includes independently varying time intervals of flashing of the red, green, and blue constant intensity light sources to form said output color image such that that the output color image has both the desired contrast and the desired brightness for each of red, green, and blue components.
15. The image producing device of claim 12, wherein said desired contrast is maximal contrast.
16. The image producing device of claim 12, wherein the video signal analyzer supplies the at least one second control signal to one of a diaphragm and the light modulator to cause said brightness adjustment such that that the output image has both the desired contrast and the desired brightness.
17. The image producing device of claim 12, wherein the analyzing of the video input derives a desired contrast and a desired brightness for a part of the output image.
18. The image producing device of claim 12, further comprising:
A light control device receiving the at least one second control signal and adjusting brightness of a part of the output image.
US11818539 1999-09-02 2007-06-14 Method of and device for generating an image having a desired brightness Active USRE42428E1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US09389177 US6631995B2 (en) 1999-09-02 1999-09-02 Method of and device for generating an image having a desired brightness
US10643245 US6905216B2 (en) 1999-09-02 2003-08-18 Method of and device for generating an image having a desired brightness
US11818539 USRE42428E1 (en) 1999-09-02 2007-06-14 Method of and device for generating an image having a desired brightness

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11818539 USRE42428E1 (en) 1999-09-02 2007-06-14 Method of and device for generating an image having a desired brightness

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10643245 Reissue US6905216B2 (en) 1999-09-02 2003-08-18 Method of and device for generating an image having a desired brightness

Publications (1)

Publication Number Publication Date
USRE42428E1 true USRE42428E1 (en) 2011-06-07

Family

ID=23537172

Family Applications (3)

Application Number Title Priority Date Filing Date
US09389177 Active US6631995B2 (en) 1999-09-02 1999-09-02 Method of and device for generating an image having a desired brightness
US10643245 Active US6905216B2 (en) 1999-09-02 2003-08-18 Method of and device for generating an image having a desired brightness
US11818539 Active USRE42428E1 (en) 1999-09-02 2007-06-14 Method of and device for generating an image having a desired brightness

Family Applications Before (2)

Application Number Title Priority Date Filing Date
US09389177 Active US6631995B2 (en) 1999-09-02 1999-09-02 Method of and device for generating an image having a desired brightness
US10643245 Active US6905216B2 (en) 1999-09-02 2003-08-18 Method of and device for generating an image having a desired brightness

Country Status (4)

Country Link
US (3) US6631995B2 (en)
EP (1) EP1127468A1 (en)
JP (1) JP2003509713A (en)
WO (1) WO2001019092A1 (en)

Families Citing this family (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001100699A (en) * 1999-09-29 2001-04-13 Canon Inc Projection display device and its application system
US20050105061A1 (en) * 2001-03-15 2005-05-19 Delong James A. Projection system with folded optical path
US6859239B2 (en) * 2001-02-26 2005-02-22 Infocus Corporation Projection system with folded optical path
EP2312380A1 (en) * 2001-02-27 2011-04-20 Dolby Laboratories Licensing Corporation A method and device for displaying an image
WO2002089106A1 (en) * 2001-04-25 2002-11-07 Matsushita Electric Industrial Co., Ltd. Video display apparatus and video display method
US20020171611A1 (en) * 2001-05-15 2002-11-21 Eastman Kodak Company Active matrix organic light emitting diode flat-panel display
JP2003114480A (en) * 2001-10-04 2003-04-18 Seiko Epson Corp Image processing meeting change of optical system of projector
ES2675880T3 (en) * 2002-03-13 2018-07-13 Dolby Laboratories Licensing Corporation Compensation fault light emitting element on a monitor
US8687271B2 (en) 2002-03-13 2014-04-01 Dolby Laboratories Licensing Corporation N-modulation displays and related methods
EP1491040B1 (en) * 2002-03-14 2006-12-13 Philips Electronics N.V. Projection device having a mode selection unit
JP2004157348A (en) * 2002-11-07 2004-06-03 Chinontec Kk Projection lens apparatus and projector apparatus
GB0228089D0 (en) * 2002-12-02 2003-01-08 Seos Ltd Dynamic range enhancement of image display apparatus
WO2005015894A3 (en) * 2003-08-08 2005-10-20 Eclipse Video Technology Llc Method and apparatus for increasing effective contrast ratio and brightness yields for digital light valve image projectors
WO2005022925A1 (en) * 2003-08-28 2005-03-10 Koninklijke Philips Electronics N.V. Method and system for controlling dynamic contrast for in a display system
US7303949B2 (en) * 2003-10-20 2007-12-04 International Business Machines Corporation High performance stress-enhanced MOSFETs using Si:C and SiGe epitaxial source/drain and method of manufacture
JP4158757B2 (en) * 2003-12-24 2008-10-01 セイコーエプソン株式会社 Optical display device and projection display device
CN1670791B (en) * 2004-02-12 2010-11-10 精工爱普生株式会社 Optical display device and image display method
EP1733372A1 (en) 2004-03-26 2006-12-20 Philips Electronics N.V. Display device comprising an adjustable light source
JP4123193B2 (en) * 2004-06-04 2008-07-23 セイコーエプソン株式会社 An image display device, a projector, polarization compensation optical system
JP4415377B2 (en) * 2004-06-24 2010-02-17 セイコーエプソン株式会社 Light source driving method and projector
US7614753B2 (en) * 2005-10-31 2009-11-10 Hewlett-Packard Development Company, L.P. Determining an adjustment
CN101460987A (en) * 2006-06-06 2009-06-17 Nxp股份有限公司 Display device and method of providing illumination thereto
US8981663B2 (en) * 2006-10-16 2015-03-17 Luxim Corporation Discharge lamp using spread spectrum
WO2008048600A9 (en) * 2006-10-16 2008-07-31 Luxim Corp Modulated light source systems and methods
US7934837B2 (en) * 2007-09-28 2011-05-03 Sanyo Electric Co., Ltd. Projection display device
US20090322800A1 (en) 2008-06-25 2009-12-31 Dolby Laboratories Licensing Corporation Method and apparatus in various embodiments for hdr implementation in display devices
JP2010039329A (en) * 2008-08-07 2010-02-18 Sony Corp Projector display device and image display control method
US20100214282A1 (en) 2009-02-24 2010-08-26 Dolby Laboratories Licensing Corporation Apparatus for providing light source modulation in dual modulator displays
WO2018141625A1 (en) 2017-02-03 2018-08-09 Philips Lighting Holding B.V. Light concentrator module
WO2018177760A1 (en) 2017-03-28 2018-10-04 Philips Lighting Holding B.V. Light concentrator module with high refractive index interconnect

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01239589A (en) 1988-03-22 1989-09-25 Toshiba Corp Image display device
US5597223A (en) 1993-12-27 1997-01-28 Kabushiki Kaisha Toshiba Display apparatus
US5622418A (en) 1994-03-29 1997-04-22 Mitsubishi Denki Kabuskiki Kaisha Projection display device
US5675391A (en) 1994-03-23 1997-10-07 Kabushiki Kaisha Toshiba Contrast/brightness control circuit for television receiver
US5717422A (en) 1994-01-25 1998-02-10 Fergason; James L. Variable intensity high contrast passive display
US5806950A (en) 1994-06-03 1998-09-15 Kopin Corporation Compact high resolution light valve projector

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2953084B2 (en) * 1991-03-20 1999-09-27 セイコーエプソン株式会社 Projection-type display device
JP3019574B2 (en) * 1992-01-17 2000-03-13 三菱電機株式会社 Projection display device
US5379083A (en) * 1994-02-15 1995-01-03 Raychem Corporation Projector
US5924783A (en) * 1997-07-24 1999-07-20 Raychem Corporation System for controlling contrast in projection displays

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01239589A (en) 1988-03-22 1989-09-25 Toshiba Corp Image display device
US5597223A (en) 1993-12-27 1997-01-28 Kabushiki Kaisha Toshiba Display apparatus
US5717422A (en) 1994-01-25 1998-02-10 Fergason; James L. Variable intensity high contrast passive display
US5675391A (en) 1994-03-23 1997-10-07 Kabushiki Kaisha Toshiba Contrast/brightness control circuit for television receiver
US5622418A (en) 1994-03-29 1997-04-22 Mitsubishi Denki Kabuskiki Kaisha Projection display device
US5806950A (en) 1994-06-03 1998-09-15 Kopin Corporation Compact high resolution light valve projector

Also Published As

Publication number Publication date Type
JP2003509713A (en) 2003-03-11 application
US20030063263A1 (en) 2003-04-03 application
EP1127468A1 (en) 2001-08-29 application
US6631995B2 (en) 2003-10-14 grant
US6905216B2 (en) 2005-06-14 grant
US20040051851A1 (en) 2004-03-18 application
WO2001019092A1 (en) 2001-03-15 application

Similar Documents

Publication Publication Date Title
US6863401B2 (en) Illumination system
US6683657B1 (en) Projection display device and application system of same
US5428408A (en) Color correction system for projection video system utilizing multiple light sources
US7270425B2 (en) Projection type video display
US7159987B2 (en) Display device, lighting device and projector
US6388718B1 (en) LCD projector of two-plate type
US6252636B1 (en) Pulsed two lamp single light valve display system
US7175281B1 (en) Method and apparatus to increase the contrast ratio of the image produced by a LCoS based light engine
US5517263A (en) Image projection system and method of using same
US6330039B2 (en) Picture display apparatus for displaying a colored picture
US6309071B1 (en) Liquid crystal projection display system
US6561654B2 (en) Image display device
US6520648B2 (en) Lamp power pulse modulation in color sequential projection displays
US20030142275A1 (en) Projection type display, a display and a drive method thereof
US20060274286A1 (en) Image presentation device with light source controller
US7147331B2 (en) Method of driving a spatial light modulator and projector
US7391475B2 (en) Display image generation with differential illumination
US7283181B2 (en) Selectable color adjustment for image display
US6843566B2 (en) Lighting device and projection type display apparatus using the same
US20020050987A1 (en) Display device
JPH10326080A (en) Video display device and method
JP2001188196A (en) Projection type display device
US7460179B2 (en) Adaptive image display
US20060001838A1 (en) Illuminating device and projection type video display
US20060132403A1 (en) Display systems with and methods for multiple source colour illumination

Legal Events

Date Code Title Description
FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12