Abstract: System and methods for measuring operating parameters of a fuel cell system are presented. In certain embodiments, the systems and methods may be configured to measure a high frequency resistance of a fuel cell system. A method for measuring a high frequency resistance of a fuel cell system may include inducing a current signal and a voltage signal through the FC system at a center frequency using a switched load. The current signal and the voltage signal may then be measured and filtered to isolate the current signal and the voltage signal from noise signals occurring in the FC system. A high frequency resistance of the FC may then be calculated based on the filtered current and voltage signals.

Abstract: System and methods for measuring operating parameters of a fuel cell system are presented. In certain embodiments, the systems and methods may be configured to measure a high frequency resistance of a fuel cell system. A method for measuring a high frequency resistance of a fuel cell system may include inducing a current signal and a voltage signal through the FC system at a center frequency using a switched load. The current signal and the voltage signal may then be measured and filtered to isolate the current signal and the voltage signal from noise signals occurring in the FC system. A high frequency resistance of the FC may then be calculated based on the filtered current and voltage signals.

Abstract: A color projection display in which at least one color channel includes: a light source assembly including a multiplicity of pulse modulated light sources providing an aggregate light beam; a light modulation control subsystem; illumination optics to direct the aggregate light beam to an image modulation plane; and a spatial light modulator in the image modulation plane. The light modulation control subsystem senses an aggregate light intensity signal for the aggregate light beam and controls the pulse modulation parameters for the multiplicity of pulse-modulated light sources responsive to the sensed aggregate light intensity signal to reduce light intensity fluctuations in the aggregate light beam within the imaging time interval.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: Etendue maintaining polarization switching occurs, according to various embodiments, with a mirror that quickly transitions between two positions. Light having uniform polarization is transmitted to the mirror. Light reflected off of the mirror in one of the two positions has its polarization changed, whereas light reflected off of the mirror in the other of the two positions has its polarization maintained. Thereafter, the polarization-changed light and the polarization-maintained light easily may be recombined in an entendue-maintaining manner. Because the recombined light includes two different polarization states, stereoscopic images may be generated.

Abstract: A color projection display in which at least one color channel includes: a light source assembly including a multiplicity of pulse modulated light sources providing an aggregate light beam; a light modulation control subsystem; illumination optics to direct the aggregate light beam to an image modulation plane; and a spatial light modulator in the image modulation plane. The light modulation control subsystem senses an aggregate light intensity signal for the aggregate light beam and controls the pulse modulation parameters for the multiplicity of pulse-modulated light sources responsive to the sensed aggregate light intensity signal to reduce light intensity fluctuations in the aggregate light beam within the imaging time interval.

Abstract: Etendue maintaining polarization switching occurs, according to various embodiments, with a mirror that quickly transitions between two positions. Light having uniform polarization is transmitted to the mirror. Light reflected off of the mirror in one of the two positions has its polarization changed, whereas light reflected off of the mirror in the other of the two positions has its polarization maintained. Thereafter, the polarization-changed light and the polarization-maintained light easily may be recombined in an entendue-maintaining manner. Because the recombined light includes two different polarization states, stereoscopic images may be generated.

Abstract: Etendue maintaining polarization switching occurs, according to various embodiments, with a mirror that quickly transitions between two positions. Light having uniform polarization is transmitted to the mirror. Light reflected off of the mirror in one of the two positions has its polarization changed, whereas light reflected off of the mirror in the other of the two positions has its polarization maintained. Thereafter, the polarization-changed light and the polarization-maintained light easily may be recombined in an entendue-maintaining manner. Because the recombined light includes two different polarization states, stereoscopic images may be generated.

Abstract: A digital image projector includes a first polarized light source; a second polarized light source that is orthogonal in polarization state to the first polarized light source; a polarization beamsplitter disposed to direct light of either the first or second polarization along a common illumination axis; a MEMS spatial light modulator; and projection optics for delivering imaging light from the MEMS spatial light modulator.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: In a light projection system, potentially hierarchical levels of light intensity control ensure proper laser-light output intensity, color channel intensity, white point, left/right image intensity balancing, or combinations thereof. The light projection system can include a light intensity sensor in an image path, in a light-source subsystem light-dump path, in a light-modulation subsystem light-dump path, in a position to measure light leaked from optical components, or combinations thereof.

Abstract: Etendue maintaining polarization switching occurs, according to various embodiments, with a mirror that quickly transitions between two positions. Light having uniform polarization is transmitted to the mirror. Light reflected off of the mirror in one of the two positions has its polarization changed, whereas light reflected off of the mirror in the other of the two positions has its polarization maintained. Thereafter, the polarization-changed light and the polarization-maintained light easily may be recombined in an entendue-maintaining manner. Because the recombined light includes two different polarization states, stereoscopic images may be generated.

Abstract: A digital image projector includes a first polarized light source; a second polarized light source that is orthogonal in polarization state to the first polarized light source; a polarization beamsplitter disposed to direct light of either the first or second polarization along a common illumination axis; a MEMS spatial light modulator; and projection optics for delivering imaging light from the MEMS spatial light modulator.