A nitride semiconductor device including a light emitting device comprises a n-type region of one or more nitride semiconductor layers having n-type conductivity, a p-type region of one or more nitride semiconductor layers having p-type conductivity and an active layer between the n-type region and the p-type region. In such devices, there is provided with a super lattice layer comprising first layers and second layers which are nitride semiconductors having a different composition respectively. The super lattice structure makes working current and voltage of the device lowered, resulting in realization of more efficient devices.

Nitride semiconductor device

The present invention provides a method and apparatus for the production and labeling of objects in a manner suitable for the prevention and detection of counterfeiting. Thus, the system incorporates a variety of features that make unauthorized reproduction difficult. In addition, the present invention provides an efficient means for the production of labels and verification of authenticity, whereby a recording apparatus which includes a recording medium, having anisotrophic optical domains, along with a means for transferring a portion of the recording medium to a carrier, wherein a bulk portion of the recording medium has macroscopically detectable anisotrophic optical properties and the detecting apparatus thereon.

Authentication method and system

A nitride semiconductor laser device has an improved stability of the lateral mode under high output power and a longer lifetime, so that the device can be applied to write and read light sources for recording media with high capacity. The nitride semiconductor laser device includes an active layer, a p-side cladding layer, and a p-side contact layer laminated in turn. The device further includes a waveguide region of a stripe structure formed by etching from the p-side contact layer. The stripe width provided by etching is within the stripe range of 1 to 3 μm and the etching depth is below the thickness of the p-side cladding layer of 0.1 μm and above the active layer. Particularly, when a p-side optical waveguide layer includes a projection part of the stripe structure and a p-type nitride semiconductor layer on the projection part and the projection part of the p-side optical waveguide layer has a thickness of not more than 1 μm, an aspect ratio is improved in far field image. Moreover, the thickness of the p-side optical waveguide layer is greater than that of an n-side optical waveguide layer.

Nitride semiconductor laser device

A system and method for combining a first digital generated image and one or more prestored digital images. The system include means for selecting one of the prestored digital images for and the steps of selecting an output format for printing the first digital generated image and the selected prestored image, providing the first digital generated image, combining the first digital generated image with the selected prestored digital image such that the generated image is placed in the predetermined location so as to form a merged image in accordance with the requirements of the selected output format, and for printing out the merged image in a desired format.

System for custom imprinting a variety of articles with images obtained from a variety of different sources

A method and system for tracking attitude of a device includes fixing a two-dimensional array of photosensors to the device and using the array to form a reference frame and a sample frame of images. The fields of view of the sample and reference frames largely overlap, so that there are common imaged features from frame to frame. Sample frames are correlated with the reference frame to detect differences in location of the common features. Based upon detection of correlations of features, an attitudinal signal indicative of pitch, yaw, and/or roll is generated. In the preferred embodiment, the attitudinal signal is used to manipulate a screen cursor of a display system, such as a remote interactive video system (RIVS). However, attitudinal tracking using the invention may be employed in other applications. Another aspect of the invention is that the two-dimensional array is configured to compensate for any curvilinear distortions introduced by a lens system for imaging the features within the field of view of the array.A movable device, such as an optical mouse, includes a housing, a lens system in the housing and an array of photosensors in the housing for acquiring images in light applied to the array by the lens system, the array disposed in a plurality of rows and columns defining an optical axis, adjacent columns being spaced apart by boundaries having curvatures increasing with departure from the optical axis sufficient to compensate for curvilinear distortion introduced in the images by characteristics of the lens system, the array comparing data from the images to indicate motion of features of the images relative to the housing.

Method and system for tracking attitude

Method and apparatus for determining the distance a sheet of paper, or other reflective or transmissive substrate material with a suitable, approximately planar surface, has moved in a given direction. The substrate is illuminated by reflection or transmission of light at non-normal incidence, and a linear array of N uniformly spaced light sensors is provide to receive and sense light issuing from the illuminated substrate. This produces a first or reference array of light signal strengths s1 (k) (k=1,2, . . . , N). The substrate is then moved in the given direction, and a second array of signal strengths s2 (k) (k=1, 2, . . . , N) is produced. A cross-correlation function C(K), formed from consecutive portions of the first and second light signal strength arrays, is then examined to determine the distance the substrate has moved in the given direction. A maximum in the cross-correlation function C(K) at K=K0 corresponds to displacement of the substrate in the given direction by a distance approximately equal to (MF)(K0 -i)d, where i is selected positive integer determined by the initial position of the substrate, the distance d is determined from the known spacing of the light sensors, and MF is the system optical magnification factor. The cross-correlation function can be computed with uniform or non-uniform weights in the sum. This one-dimensional approach is extended to determining the vector of two-dimensional movement of the substrate, including translation, rotation and scaling, in a two-dimensional plane.

Substrate advance measurement system using cross-correlation of light sensor array signals

A vertical-cavity surface-emitting laser that generates light having a fixed direction of polarization. The laser has a plane light-generating region sandwiched between a first conductive mirror region and a second conductive mirror region. The first conductive mirror region has an opposite conductivity mode from the second conductive mirror region. The first conductive mirror region has a remote surface substantially parallel to the light-generating region and an electrode formed on the remote surface. The electrode bounds a light emission port from which the light is emitted in a direction defining an axis. A reduced-conductivity region is formed in the first conductive mirror region surrounding the axis and extending from the remote surface towards the light-emitting region to define a core region in the first conductive mirror region. The light emission port and/or the core region has first and second dimensions in orthogonal directions in a plane parallel to the light-generating region. The first dimension is greater than the second dimension to set the direction of polarization of the light to the direction of the first dimension.

Vertical-cavity surface-emitting laser generating light with a defined direction of polarization

A sheet advancement control system for use in printers such as inkjet printers includes a light source for directing a beam of light onto a localized area of a sheet, a photosensitive detector for providing output signals that vary according to microscopic patterns that are illuminated within the sheet by the directed light, a correlator for determining cross-correlations between pairs of detected patterns as the sheet is advanced in a printer and for computing displacements between matching patterns to, thereby, detect the displacement of a sheet within the printer.

Sheet advancement control system detecting fiber pattern of sheet

A desktop printing system for use with microprocessor-based computers includes the modular combination of a color printer and a monochrome text printer. Preferably, the color printer is of the type which prints color graphics incrementally and the text printer is of the type which prints monochrome text continuously. In operation, printing information is segregated into color and text components, and the color printer is controlled to print only color components while the text printer is controlled to print only monochrome text components.

Text and color printing system

An integrated laser-based light source that generates an output light beam having a controlled intensity. The light source comprises a package, a laser, a light sensor, and a beam splitter. The beam splitter is mounted in the package, together with the laser and the light sensor. The laser has one and only one light-emitting face from which it radiates a light beam as a radiated light beam. The light sensor generates an electrical signal representing the intensity of light energy falling on it. The beam splitter divides the radiated light beam into a fraction and a remainder, the remainder being the output light beam. The beam splitter operates by diffraction, scattering, or transmission to direct the fraction of the radiated light beam towards the light sensor.

William D. Holland

Papers

Substrate advance measurement system using cross-correlation of light sensor array signals

Vertical-cavity surface-emitting laser generating light with a defined direction of polarization

Sheet advancement control system detecting fiber pattern of sheet

Text and color printing system

Integrated controlled intensity laser-based light source using diffraction, scattering and transmission