Abstract:
A system and method for controlling an electrochromic device is provided. The system comprises a light source that produces an input light signal, and an electrochromic window configured to attenuate the input light signal by a certain amount and transmit a resulting attenuated light signal. An optical detector is configured to detect an optical property of the attenuated light signal, and a power module is connected to the electrochromic window and the detector. The power module generates a pulse-width modulated power signal and inputs the power signal to the electrochromic window. The power signal is modulated by an amount based on the detected optical property of the attenuated light signal. A control circuit for an electrochromic device is also disclosed.
Abstract:
The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having a cladding that includes an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The VOA also includes a layer that is parallel to the core of the waveguide and that optically couples to the core to receive light from the attenuated signal. A power meter receives light from the layer as an indication of the amount of light attenuated from the signal and for controlling the voltage to the electrodes.
Abstract:
Backlight assembly and the display device using the same are disclosed. Backlight assembly comprises a container and a detector. The container holds a light and electromagnetic field generating source and a sampling portion for passing the light and/or electromagnetic field. The detector is located on the outer space of the container and has an electromagnetic field reactive sensing unit and a body to support the sensing unit. Therefore, the backlight of the present invention can protect lamp from the successive malfunctioning and prevent fire.
Abstract:
A photodetector for use with relatively thin (i.e., sub-micron) silicon optical waveguides formed in a silicon-on-insulator (SOI) structure comprises a layer of poly-germanium disposed to couple at least a portion of the optical signal propagating along the silicon optical waveguide. Tight confinement of the optical signal within the waveguide structure allows for efficient evanescent coupling into the poly-germanium detector. The silicon optical waveguide may comprise any desired geometry, with the poly-germanium detector formed to either cover a portion of the waveguide, or be butt-coupled to an end portion of the waveguide. When covering a portion of the waveguide, poly-germanium detector may comprise a “wrap-around” geometry to cover the side and top surfaces of the optical waveguide, with electrical contacts formed at opposing ends of the detector.
Abstract:
An electronic display apparatus includes a substrate, pixels and light sensing parts. The substrate includes a display region and a peripheral region adjacent the display region, and the substrate includes a plurality of gate lines extended in a first direction and a plurality of data lines extended in a second direction that is substantially perpendicular to the first direction. The pixels defined by each of the data and gate lines are formed in the display region to display an image. The light sensing part is formed in the peripheral region, and the light sensing part senses an intensity of an ambient light. The light sensing part that senses an intensity of an ambient light is formed on the array substrate, so that a luminance of the display apparatus may be adjusted in accordance with the intensity of the ambient light.
Abstract:
A system and method for controlling an electrochromic device is provided. The system comprises a light source that produces an input light signal, and an electrochromic window configured to attenuate the input light signal by a certain amount and transmit a resulting attenuated light signal. An optical detector is configured to detect an optical property of the attenuated light signal, and a power module is connected to the electrochromic window and the detector. The power module generates a pulse-width modulated power signal and inputs the power signal to the electrochromic window. The power signal is modulated by an amount based on the detected optical property of the attenuated light signal. A control circuit for an electrochromic device is also disclosed.
Abstract:
Energy efficient transmissive and transreflective display devices are described. Ambient light from a natural or artificial source is used to replace and/or supplement light normally supplied by a backlight. This is done by directing ambient light to the rear of a transmissive display panel. A window, light tunnel, or a reflective surface located in the rear or top of a display device may be used to direct the ambient light to the back of the display panel. A translucent diffuser and/or diffuse reflector are used to diffuse the ambient light to reduce the chance of bright spots appearing on the display. Additional energy efficiency is achieved by using one or more photo-sensors to detect the amount of light, incident on the front and/or rear of a display panel and by automatically adjusting the backlight intensity as a function of photo-sensor output. In this manner, backlight intensity can be minimized while maintaining the viewability of images shown on the display. In such an embodiment, energy savings are achieved as compared to devices which use fixed backlight intensity settings in a variety of light conditions. Control of the power supplied to a display's backlight in accordance with the present invention can reduce electrical energy consumption and prolong the amount of time a portable device can be used before its batteries need to be recharged.
Abstract:
A photodetector for use with relatively thin (i.e., sub-micron) silicon optical waveguides formed in a silicon-on-insulator (SOI) structure comprises a layer of poly-germanium disposed to couple at least a portion of the optical signal propagating along the silicon optical waveguide. Tight confinement of the optical signal within the waveguide structure allows for efficient evanescent coupling into the poly-germanium detector. The silicon optical waveguide may comprise any desired geometry, with the poly-germanium detector formed to either cover a portion of the waveguide, or be butt-coupled to an end portion of the waveguide. When covering a portion of the waveguide, poly-germanium detector may comprise a nullwrap-aroundnull geometry to cover the side and top surfaces of the optical waveguide, with electrical contacts formed at opposing ends of the detector.
Abstract:
According to one embodiment of the present invention, an electrochromic rearview mirror assembly for a vehicle includes an electrochromic mirror having a variable reflectivity, a glare sensor for sensing levels of light directed towards the front element from the rear of the vehicle, an ambient sensor for sensing levels of ambient light, a display positioned behind the partially transmissive, partially reflective portion of the reflector for displaying information therethrough; and a control circuit coupled to the sensors and the display. The control circuit determines whether daytime or nighttime conditions are present as a function of the ambient light level sensed by the ambient sensor. During daytime conditions, the control circuit responds to light levels sensed by the glare sensor to control a contrast ratio of light originating from the display and light reflecting from the partially transmissive, partially reflective area of the reflector.
Abstract:
A light source of a liquid crystal panel employed in a head up display for a vehicle has an embedded filament for emitting a light with high luminance and another embedded filament for emitting a light with low luminance. The embedded filament for emitting a light with low luminance is used for a first luminance range. On the other hand, the embedded filament for emitting a light with high luminance is used for a second luminance range. In addition, both the elements may be used at the same time for emitting a light with maximum luminance of the first range and the second range.