摘要:
A super-resolving imaging apparatus employs diffractive optical elements placed on the imaging lens. This element, and the use of a modified Scheimpflug arrangement allow the conversion of degrees of freedom in one axis of a field of view to a larger degree of freedom in another axis in order to obtain a high resolution image with a wide depth of focus and large field of view. Replicas created by the diffractive elements are mutually shifted by subpixel amounts, and are combined using a Gabor transform, which is facilitated by a spatial mask placed over the detector array. The apparatus is suitable for performing distance estimation on an object within the field of view.
摘要:
A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.
摘要:
In order to improve security for holographic labels which are positioned on a substrate base, a bar code symbol is holographically recorded on the base such as a credit card, a label, or a container for a product. A reading apparatus (e.g., a bar code reader) directs light at the holographic bar code symbol and detects the reflected optical information with a detector such as a CCD array. The reading apparatus can be a stand-alone device or, in the case of a credit card, can be incorporated into a conventional swiper for reading magnetic information on a strip on the card. A non-holographic bar code symbol can also be provided on or near a holographic display element, e.g., a rainbow hologram. The bar code can be positioned adjacent the display, or placed in a window within the display, or etched or embossed on the display. A system is also provided for authenticating a holographic display on an information card such as a credit card. A display is illuminated and a reflected beam directed at a holographic record which was previously produced from a signal, known to be authentic, and a reference. The reflected beam is used to reconstruct a reference beam. A sensor receives the reconstructed reference and it is then determined if the display is authentic.
摘要:
A bar code detector or acquisition arrangement for detecting the presence and location of a bar code pattern in a field of view. The bar code pattern detector is not designed to decode a bar code pattern, but merely to be sensitive to and detect the presence of a bar code pattern or patterns so that a conventional bar code scanner can then be activated to perform a decoding operation thereon. The present invention is based upon the generation of Moire patterns, and includes an electro-optic system for detecting and locating a bar code pattern in which an image of a field of view is projected onto a reference bar code pattern or an image thereof while producing relative rotation between the image of the field of view and the reference bar code pattern or image thereof. An optical detector detects the optical interaction of the image of the field of view with the reference bar code pattern or image thereof, including any Moire patterns generated thereby. A processor is coupled to the output of the optical detector for detecting the generation of any such Moire patterns, which are indicative of the presence and location of a bar code pattern or patterns in the field of view.
摘要:
A bar code scanner is disclosed employing a laser source and scan mirror for generating a light beam for scanning a bar code symbol or the like. The working range for distance between the scanner and the symbol is extended by placing an optical element in the path between the laser source and the scan mirror. This optical element may be a figure of rotation such as an axicon. A slit may be positioned downstream of the axicon to block the characteristic concentric rings produced in the beam in areas perpendicular to the scan line.
摘要:
A high frequency spectral analysis system and method operates by modulating an optical beam with a high frequency signal to be analyzed, and sampling the beam simultaneously at periodically spaced locations along its length. The sampled portions are then focused to a spectral mapping. In the preferred embodiment a beam is directed in a zigzag pattern through a plate, one surface of which is totally reflective and the opposite surface of which is partially reflective. Periodic parallel samples are obtained from the minor portions of the beam which are transmitted out of the plate through the partially reflective surface. The totally reflective surface is preferably formed as a series of cylindrical surfaces which focus the beam to small spots at the partially reflective surface, thereby permitting a higher spatial density of samples without overlapping. The plate thickness is selected so that the beam is sampled at the Nyquist rate for the highest frequency contained in the signal of interest.
摘要:
Associative holography memory apparatus is disclosed which employs a hologram and two phase conjugate mirrors. The mirrors are arranged to form a conjugate resonator whereby the output image from the apparatus tends to converge to that stored image most closely associated with an input image. Alternate embodiments are described which employ a multiple storage and erasure hologram, and which employ only a single phase conjugate mirror.
摘要:
A method of optical element manufacturing, the method may include selecting a range of a misfocus parameter ψ; and designing the optical element to comprise multiple regions, wherein the optical transfer function (OTF) of the optical element allows, for the range of the misfocus parameter ψ, transmission of images with a contrast of at least 10% for all normalized spatial frequencies up to 50% of a theoretical maximum that is attainable with a full aperture in an in-focus condition.
摘要:
A method of optical data processing, comprising: providing a first data set to be optically transformed using a transform; combining a reference data set with said first data set to generate coherent light, encoding a combined data set; optically and coherently transforming said light that encodes the combined data set, into coherent light that encodes a transformed combined data set; obtaining a transformed reference data set by determining the effect said optical transform has on light encoding said reference data set; and extracting a second data set that represents a transform of said first data set, from an intensity portion of light encoding said transformed combined data set, using said transformed reference data set to extract a phase of at least one element of said second data set.
摘要:
An improved optical system for scanning optical codes is disclosed. A laser beam produced thereby is a diverging, nearly diffraction free beam and may be used to produce an elongated scanning spot. A laser assembly which may be used to produce such beams and spots, combines various optical functions in structures which are relatively insensitive to temperature change.