Optics: image projectors – Reflector – Plural
Reexamination Certificate
2003-04-04
2004-08-24
Mahoney, Christopher (Department: 2851)
Optics: image projectors
Reflector
Plural
C353S122000, C359S223100
Reexamination Certificate
active
06779898
ABSTRACT:
FIELD OF INVENTION
The present invention generally relates to an image display apparatus and a method for enhancing image brightness, and more particularly, to an image display apparatus and a method for recapturing off-state light to enhance image brightness.
BACKGROUND OF THE INVENTION
In parallel with the progress of business activities and the development of interactive learning, projectors become indispensable image forming apparatuses in many kinds of business events. Therefore, the image displaying technology is advancing from the liquid crystal display to the digital light processing (DLP).
The digital light processing technology employs the reflected light, which is modulated by the spatial light modulator (SLM), such as commonly known digital micromirror device (DMD). The DMD has an array of micromirrors. By controlling the tilt angle of each micromirror individually, every micromirror can be selectively arranged in two states, such as “on” state and “off” state. Referring to
FIG. 1
, a block diagram of a conventional image display apparatus is illustrated. When the light beam provided by the light source
10
travels through integrator
20
and filter
30
and impinges on the DMD
40
, according to image signals, the controller
70
determines the corresponding state of each micromirror. When the image signal is on, the corresponding micromirror is in the on state and the light beam is reflected to form an image on screen
50
. When the image signal is off, the corresponding micromirror is in the off state and the light beam is reflected to other direction and absorbed by absorber
60
or converted to heat.
Brightness, resolution, weight, light source lifetime are indices for determining the quality of a projector. The brightness indicating the intensity of light projected on a screen determines whether a projector can have an effective image even in a bright environment. If the brightness achieves some level, the projector can have a projected image of good quality without the need of darkening the environment or turning off the facility light.
Light source is a component directly relating to the brightness of projectors. In general, the projector displays image of higher brightness as the light source has larger power (or wattage). However, purely increasing power of the light source to improve the brightness cannot improve the total quality of a projector because, for example, a light source of higher power generates more heat, which requires a better heat dissipation mechanism, such as a larger fan. When the fan becomes larger, the noise becomes louder and the size of the projector increases at the same time. Therefore, increasing the power of light source to improve the brightness must sacrifice other aspects of quality.
Therefore, there is a need to provide an image display apparatus and a method for improving the brightness of the apparatus without inducing more heat problems.
OBJECTS AND SUMMARY OF THE INVENTION
One aspect of the present invention is to provide an image display apparatus, which recaptures off-state light to enhance image brightness. When a spatial light modulator is in the off state, a reflector is implemented to reflect the off-state light, which is then collected and recycled. When the spatial light modulator is in the on state, the collected off-state light is modulated to enhance the brightness of image on a screen.
In a first exemplary embodiment of the present invention, the image display apparatus includes a spatial light modulator, a reflector, and an integrator element. The spatial light modulator, in response to a light beam, selectively modulates the light beam along a first path to form a first path light beam. The reflector reflects the first path light beam to form a reflected light beam. The integrator element collects and reflects the reflected light beam to form a recapture light beam. Further, the spatial light modulator modulates the recapture light beam along a second path to form an image on a screen.
In a second exemplary embodiment of the present invention, an image display apparatus including a light source, an integrator element, a spatial light modulator, and a reflector is provided. The light source provides a light beam, which enters the integrator element at a first end and exits from a second end. The spatial light modulator selectively modulates the light beam along a first path to form a first path light beam. The reflector reflects the first path light beam to form a reflected light beam. The reflected light beam modulated by the spatial light modulator enters the integrator element at the second end along a reverse path. The integrator element collects and reflects the reflected light beam to form a recapture light beam, so that the spatial light modulator modulates the recapture light beam along a second path to form an image on a screen.
The present invention also provides a method for recapturing off-state light. The method includes the step of providing a light beam, which is then selectively modulated along a first path by a spatial light modulator to form a first path light beam. The first path light beam is reflected to form a recapture light beam, which is then modulated along a second path by the spatial light modulator to form an image on a screen.
REFERENCES:
patent: 5633755 (1997-05-01), Manabe et al.
patent: 6309074 (2001-10-01), Inbar et al.
patent: 6454417 (2002-09-01), Takamoto et al.
patent: 6474818 (2002-11-01), Engle
patent: 6601959 (2003-08-01), Miyata et al.
patent: 6739723 (2004-05-01), Haven et al.
Benq Corporation
Mahoney Christopher
Snell & Wilmer L.L.P.
LandOfFree
Image display apparatus and method for recapturing off-state... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image display apparatus and method for recapturing off-state..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image display apparatus and method for recapturing off-state... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3345697