At&t Bell Laboratories

Lucent Technologies Inc.

At+t Corp.

At&t Technologies, Inc.

Rajarshi Ray

Chinmoy B Bose

Suresh Goyal

Robert B Levy

David R Riese

A portable wireless communication terminal includes electronics for receiving and transmitting both video and audio signals. The electronics are housed in rugged, drop-tolerant consoles, which are interconnected so that they may be extended and reconfigured relative to each other for convenient use and easy, compact storage. A camera lens is included in a camera console, a video display is included in a video display console, and alphanumerical keys are included in a base console. The camera console can be rotated relative to the video display console so that the user can transmit a video signal of the surroundings while watching the video display. Further, the video display console can be extended and tilted relative to the base console.

Wireless communication terminal having a video image capability

A wireless communication terminal is configured for enabling a user to receive and transmit video images as well as receive and transmit audio or speech signals associated with the user of the terminal and another user at, for example, a remote location. The received video image is obtained from a video image signal received over a radio frequency communications link established between the wireless communication terminal and a cellular base station. This received video image is displayed in a video image display conveniently associated with the wireless communication terminal. The transmitted video image signal may be that of the user of the terminal, of a scene within the field of view of the video camera or of text either coupled to the terminal through one of many well known data interfaces, or an image of text as captured by the camera. This transmitted video image signal is obtained from a video camera associated with the wireless communication terminal and then transmitted over the radio frequency communications link established between the wireless communication terminal and the cellular base station for displaying in a remotely located video image display.

Wireless communication terminal having video image capability

Compression of a plurality of signal samples y(t.sub.0),y(t.sub.1),y(t.sub.2) . . . y(t.sub.z) may be accomplished by performing a first linear regression to obtain a curve fitted thereto which is represented by a polynomial having a first set of coefficients (a.sub.0,a.sub.1,a.sub.2,a.sub.3 . . . a.sub.n) which is stored in memory (18) or transmitted by a transmitter (20). The error between each of the actual signal samples (y(t.sub.0),y(t.sub.1),y(t.sub.2) . . . y(t.sub.z) and the value approximated by the curve fitted to the values is computed and then thresholded. A second regression analysis is then performed to fit a curve, having a second set of coefficients (b.sub.0,b.sub.1,b.sub.2,b.sub.3 . . . b.sub.q) to the thresholded error values. The second set of coefficients is also stored or transmitted and used, in conjunction with the first set of coefficients, to closely approximate the original set of signal samples.

Method for data compression

In-situ removal of material, such as solder paste (12), from openings (26--26) in a stencil (22) is accomplished by imparting a vibrational motion to the stencil. In practice, the stencil (22) may be vibrated by one or more DC solenoids (28--28), each having its plunger (28) in contact with the periphery of the stencil and each excited with AC so that the solenoid plunger undergoes a linear oscillation to vibrate the stencil.

Method and apparatus for in-situ removal of material from openings in a

Detection of a defect (18) on the surface (15) of an article (10), such as a semiconductor chip, is accomplished by illuminating the chip in a bright field and then capturing the image thereof with a television camera (30) coupled to a machine vision processor (32). To detect the defect (18), the vision processor first adaptively thresholds the captured image to effectively eliminate areas in the image brighter than those associated with the defect (18) which are usually dark. Thereafter, the vision processor (32) erodes and then dilates the dark areas within the image remaining after binarization to isolate those dark areas associated with the defect. The existence of a defect can then be established by the existence of a now-isolated dark area.

Method and apparatus for surface inspection

The contrast of an LCD cell (12) is enhanced by the use of a gradient index plate mirror (16',16') positioned behind the cell to reflect light from a light source (14',14') through the cell in a well-collimated beam. The mirror (16',16') is formed of an optical plate (34',34') having first and second major surfaces (36',36') and (38',38'), the latter having a reflective coating (40',40') thereon. The optical plate (34',34') has a gradient index of refraction which increases from its first to its second major surface. As a consequence, the light entering the plate and reflected back therethrough is refracted so as to be bent closer to the plate normal (42',42'), causing the light leaving the mirror and entering the LCD cell to be well collimated, which is desirable for improving the display contrast.

Gradient index mirror for providing a collimated beam for liquid crystal

Inspection of a metallized pattern (14) on a substrate (12) to monitor both the lateral dimensions and the intensity variation beyond tolerance limits is carried out by first capturing the image of the pattern with a television camera (20). The captured image is then compared to each of two models (40 and 42) comprising comparison patterns whose features have their lateral dimensions eroded and dilated, respectively, and the other aspect dilated and eroded, respectively, by a factor corresponding to the dimensional and intensity tolerances. The results of such comparison are logically combined to yield an image containing only defects (if any).

Method for monitoring the dimensions and other aspects linewidth

Distortion of the image displayed by a cathode ray tube display (10,10') can be compensated by placing a flat-plate optical device, fabricated from two plates (14,14') of optical material joined at their edges an an angle, in the field of view of the display. Each of the plates (14,14') is advantageously constructed so as to have a gradient index of refraction such that the index of the plate changes across its length from its free edge to the vertex (16) formed with the other plate. By fabricating each of the plates (14 and 14') such that the index of refraction of each decreases or increases from the free edge of each plate to the vertex formed with the other plate, the device formed by the plates will compensate for either barrel or pincushion distortion, respectively.

Flat-plate optical device having a gradient index of refraction for

Defective or missing solder bumps (18) on a surface (13) of an article (10) such as a chip carrier are detected by first illuminating the surface with dark field illumination. Next, the image of the surface of the article is captured, typically by a television camera (30). The captured image is processed to detect defects by first creating a window (57) in the image about each group of solder bumps and then creating a bounding box (58) about each bump in each window. Each of a set of attributes, including: the number, size and location of the windows, the size location and number of boxes in each window, and the dimensions, shape and brightness of the image in each box, is measured. The value of each attribute is compared to a reference value, representing the value of the attribute when no defects are present. If the attribute differs by more than a predetermined tolerance for its reference value, than a particular defect is prevent. Verification of certain defects may be accomplished by repeating the above-described process using bright field illumination.

Method and apparatus for inspection of specular, three-dimensional

Accurate inspection of a pattern (14) of metallized areas (12) printed on a substrate (10) is accomplished by compensating the pattern for any deformation prior to comparing the image thereof to that of a perfect (master) pattern (14'). The amount of compensation is determined by first capturing the image of selected elements in the pattern with the aid of a television camera (32). A machine vision processor (36) processes the output of the camera (32) to determine the offset of each of the selected elements in the pattern from the corresponding elements within a master pattern (14') which represents a perfectly formed version of the actual pattern (14). From the amount of offset between the selected elements in the pattern (14) and the corresponding elements in the master pattern (14'), the amount of pattern deformation at the preselected elements, as well as at all intermediate sites, is determined and the pattern is compensated accordingly.

Method and apparatus for pattern inspection

Detection of a defect (18) on the surface (15) of an article (10), such as a semiconductor chip, is accomplished by illuminating the chip in a bright field and then capturing the image thereof with a television camera (30) coupled to a machine vision processor (32). To detect the defect 18, the vision processor first adaptively thresholds the captured image to effectively eliminate areas in the image brighter than those associated with the defect (18) which are usually dark. Thereafter, the vision processor (32) erodes and then dilates the dark areas within the image remaining after binarization to isolate those dark areas associated with the defect. The existence of a defect can then be established by the existence of a now-isolated dark area.

Automated inspection of solder bumps (18--18) on a major surface (14) of a chip carrier (10) is accomplished by placing the chip carrier on a platform (22) beneath a ring light (28) which is in registration with a television camera (30). Light from the ring light, which is directed at an angle towards all sides (12--12) of the chip carrier, is only reflected upwardly into the television camera by the solder bumps. The output signal of the television camera, which varies with the intensity of the light reflected from the solder bumps, is processed by a vision system (32) to obtain a one-dimensional plot of the light intensity. The one-dimensional intensity plot is analyzed automatically by the vision system to detect for missing, bridged or excessive solder bumps on the chip carrier.

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Princeton, NJ, United States of America

Rajarshi Ray