摘要:
The present invention provides a spectroscopic system and a transmission based imaging system for a spectroscopic system as well as a probe head for a transmission based imaging system for a spectroscopic system and a corresponding transmission based imaging method. The spectroscopic system is preferably applicable to in vivo noninvasive blood analysis. Transmission based imaging makes use of a transmitted portion of an imaging or monitoring beam that has been transmitted through biological tissue. By means of transmission based imaging, a contrast decreasing impact of scattered radiation can be effectively reduced. Additionally, by arranging the imaging light source opposite to an objective lens of the spectroscopic system, unintended propagation of spectroscopic excitation radiation into free space can be effectively prevented.
摘要:
The invention relates to an information carrier (101) intended to be read and/or written by a periodic array of light spots, said information carrier (101) comprising a data area (105) defined by a set of elementary data areas, a first periodic structure (108) intended to interfere with said periodic array of light spots for generating a first moiré pattern, a second periodic structure (109) intended to interfere with said periodic array of light spots for generating a second moiré pattern, said second periodic structure (109) being arranged perpendicularly to said first periodic structure (108). The invention also relates to an apparatus for reading and/or writing said information carrier (101).
摘要:
The present invention relates to a system for copy protection of an information carrier, said system comprising a diffractive layer for delivering a speckle pattern when illuminated by a light source, a spatial filter, which is aligned with respect to the diffractive layer, for delivering a filtered optical signal from the speckle pattern and a detector array for delivering, when illuminated by said filtered optical signal, an electrical signal. Said system further comprises means for computing a cryptographic key from the electrical signal, and means for decrypting encrypted data contained in the information carrier from the cryptographic key. It finds its application in copy protection of content carriers such as optical discs or in smart cards.
摘要:
The optical analysis system (1) is arranged to determine an amplitude of a principal component of an optical signal. The optical analysis system (1) comprises a first detector (5) for detecting the optical signal weighted by a first spectral weighting function, and a second detector (6) for detecting the optical signal weighted by a second spectral weighting function. For an improved signal-to-noise ratio, the optical analysis system (1) further comprises a dispersive element (2) for spectrally dispersing the optical signal, and a distribution element (4) for receiving the spectrally dispersed optical signal and for distributing a first part of the optical signal weighted by the first spectral weighting function to the first detector (5) and a second part of the optical signal weighted by the second spectral weighting function to the second detector (6). The spectroscopic analysis system (30) and the blood analysis system (40) each comprise an optical analysis system (1) according to the invention.
摘要:
An LED light source for LCD backlighting is described that recalibrates itself over time so that color and brightness uniformity across the backlight is maintained over the life of the backlight. The backlight contains clusters of red, green, and blue LEDs, each cluster generating a white point. In one embodiment, each color in a cluster has its own controllable driver so that the brightness of each color is a cluster is separately controllable. One or more optical sensors are arranged in the backlight, and the sensor signals are detected by processing circuitry to sense the light output of any LEDs that are energized in a single cluster. The measured white point and flux are compared to a stored target white point value and flux for that cluster. The currents to the RGB LEDs are then automatically adjusted to achieve the target level for each cluster. This process is applied to each cluster in sequence until the recalibration is complete. The recalibration takes place at various times over the lifetime of the backlight to offset the effects of LED degradation over time. Variations of this technique are also described.
摘要:
In the described method of producing a plurality of bodies bearing equal imprints of a stamp as optical structures, a stamp (13) is initially produced, by attaching particles (14) to a surface (15) of an auxiliary body (16); than, the stamp (13) is used to produce an imprint (11) on a plurality of bodies (10). Optical structures can be irradiated, producing on a screen a speckle pattern indicative of a key. It is substantially impossible to clone a given optical structure with current technological means. Optical structures represent physical One-Way Functions, easy to compute in the forward sense but unfeasible to reverse. Thus, they can be used to build an access/copy protection system of user information contained in an information carrier associated with the body 10. The reproducibility of the optical structures makes this method suitable for optical disks.
摘要:
An analysis apparatus, in particular a spectroscopic analysis apparatus, comprises an excitation system for emitting an excitation beam to excite a target region. A a monitoring system images the target region. The monitoring system being arranged to produce a contrast image in a contrast wavelength range and produce a reference image in a reference wavelength range. the contrast image and the reference image are compared to accurately identify the target region, notably a capillary blood vessel in the patient's skin.
摘要:
An LED backlight structure and technique for setting the voltages and currents for the LEDs are described. In one embodiment, red LEDs are connected in series between a first voltage regulator and a first controllable current source, green LEDs are connected in series between a second voltage regulator and a second controllable current source, and blue LEDs are connected in series between a third voltage regulator and a third controllable current source. The current sources may linear current regulators. After all the LEDs are mounted on a printed circuit board, each voltage regulator is controlled so that there is a minimum voltage drop across the current source to minimize energy dissipation by the current source. Also, after all the LEDs are mounted on the printed circuit board, the current sources are controlled to balance the three colors to achieve a target light output of the board using a light detection chamber. In another embodiment, a constant current source is connected to the series string of LEDs. PWM controllers control transistor switches connected in parallel across groups of LEDs, where the duty cycles set the average current through each group of LEDs. The control values used to achieve the target light characteristics are then stored in a memory on the board. With such a technique, LEDs do not need to be binned to match their efficiencies, since the controllable voltage and current sources compensate for the variety of LED efficiencies. Accordingly, all boards will have the same target light output using the particular values stored on each board. In other embodiments, not all the LEDs of a particular color are connected in series. The brightness levels of the LEDs may be further controlled by a PWM controller. The backlight may be for an LCD television or other color display.
摘要:
A programmable optical component (10) for spatially controlling the intensity of a beam of radiation (b), which component comprises a programmable layer which is divided in programmable elements (4,6,8), characterized in that each programmable element comprises bendable nano-elements (8) which are switchable between a non-bend state (8) and a bend state (8′) by means of a driver field. In their bend state the nano-elements absorb radiation. The programmable element may be a switchable diffraction grating or a programmable mask.
摘要:
The optical analysis system (20) for determining an amplitude of a principal component of an optical signal comprises a multivariate optical element (10) for reflecting the optical signal and thereby weighing the optical signal by a spectral weighing function, and a detector (9, 9P, 9N) for detecting the weighed optical signal. The optical analysis system (20) may further comprise a dispersive element (2) for spectrally dispersing the optical signal, the multivariate optical element being arranged to receive the dispersed optical signal. The blood analysis system (40) comprises the optical analysis system (20) according to the invention.