摘要:
A frequency control system and method for minimizing frequency drifts in subscriber terminals in a point-to-multipoint system is described enabling the use of low cost oscillators in the Subscriber terminals by measuring the frequency offset of the subscriber terminal's receiver to estimate its oscillator frequency drift which is then used to correct the subscriber terminal's transmitter frequency and also by feedback of a frequency correction from the base station to the subscriber.
摘要:
A point-to-multipoint star configured terrestrial radio communication system having at least one base station transmitting to and receiving RF communication signals from a plurality of associated subscriber stations in the 0.3-300 GigaHertz (GHz) range. The system includes means for reducing frequency uncertainty, drift or error of the RF transmissions from each of the subscriber stations to the base station. Each subscriber station has a low cost local reference oscillator, and the system incorporates a reference broadcast signal of high frequency precision from the base station and at each subscriber station there is means for measuring frequency error and compensating for frequency drift/error in the low-cost oscillator at the subscriber station. Moreover, the system can provide an estimate obtained from measuring each subscriber frequency drift or error in the base station and relaying the measured error to the corresponding subscriber station to compensate for that subscriber's transmitter's local oscillator be out of frequency.
摘要:
A display device is provided that comprises a liquid crystal display panel for displaying an image by spatial light modulation, and circuitry for switching liquid crystal in the panel between having a first configuration in a first mode to cause an image displayed using the panel to be discernible from a wide range of viewing angles, and having a second configuration in a second mode to cause an image displayed using the panel to be discernible substantially only from within a narrow range of viewing angles. Several types of display panel to achieve such in-panel switching between public and private viewing modes are disclosed.
摘要:
A display device having a display panel for displaying an image by spatial light modulation includes a plurality of pixel groups, each pixel group including a first pixel having a first type of luminance against viewing angle response, and a second pixel having a second type of luminance against viewing angle response, wherein the first and second luminance against viewing angle responses are different from one another. The display device further includes a controller operatively coupled to each of the plurality of pixel groups, wherein the controller is configured to drive each of the plurality of pixel groups such that on average the plurality of pixel groups simultaneously provide a predetermined on-axis luminance and an predetermined off-axis luminance for a region of the image corresponding to each pixel group.
摘要:
A liquid delivery apparatus for the intrathecal delivery of one or more medications to a patient is disclosed. The liquid delivery apparatus generally includes a liquid reservoir, a liquid metering unit fluidly connected to the liquid reservoir, and a catheter delivery tube fluidly connected to the liquid metering unit. Preferably, the liquid delivery apparatus includes two or more liquid reservoirs. In various embodiments, the liquid reservoir includes a deformable balloon and a compressive sleeve spring as a pressure source, the liquid metering unit is a piezoelectrically actuated microvalve, and/or diagnostic sensors are included in the apparatus. The disclosed apparatus are compact, volume-efficient, energy-efficient, capable of delivering accurate fluid volumes, and address problems associated with multi-medication therapies. Methods of operating the liquid delivery apparatus are also disclosed.
摘要:
A display device includes a first layer having an optically active display portion, a second layer including a photovoltaic element, and a third layer including electronics operatively coupled to the first layer, wherein the electronics are configured to drive the optically active display portion. Further, the second layer is arranged between the first and third layers.
摘要:
A display comprises a backlight (30, 45-48) and a spatial light modulator (1) such as a liquid crystal device for modulating light from the backlight (30, 45-48). The backlight has a light-output surface (45) with a first set of regions in the form of parallel evenly spaced strips (48). In a multiple-view mode of the display, these strips (48) emit light whereas the remainder of the output surface (45) is dark. In a single-view mode of operation of the display, the whole of the output surface (45) emits light substantially evenly across the display area of the modulator (1).
摘要:
A light source system comprises a light source disposed within a non-imaging optical element. The non-imaging optical element does not produce a direct image of the light source, and the output light field at the output surface of the non-imaging optical element has an intensity that is substantially uniform over the area of the output surface. A light source system of the invention is therefore smaller and lighter than a prior art system of the same output power, since there is no need to provide further components, such as an integrator, to homogenise the output light field.
摘要:
A light emitting device may include a light emitting layer including an organic semiconductor material with a liquid crystalline structure, one or more feedback structures, and a coupling structure. The one or more feedback structures may cause light emitted by the light emitting layer to be fed back through it along an axis in the plane of the device, thereby promoting the stimulated emission of light in the light emitting layer. The coupling structure couples some fraction of the feedback light out of the device. The coupled light may be emitted along an axis substantially normal to the plane of the device or at predetermined angles. The coupling and feedback structures may have a corrugated structure, a continuous variation of refractive index along an axis in the device plane, a period refractive index, or any combination thereof. The coupling and feedback structures may be separate, share common portion or combined together.
摘要:
A display is provided having first and second direct view modes of operation. The display comprises a liquid crystal display panel and a backlight which is illuminated during the first mode so that the displayed image is visible throughout an extended viewing region in front of the device. The display also comprises a holographic element and a front light source, which is switched on for the second direct view mode. The holographic element redirects light from the front light source into part of the extended viewing region so that an image displayed by the device is visible in only a restricted portion of the viewing region.