Abstract: Integrated inspection and test systems for liquid crystal display (LCD) active plates. The integrated inspection and test systems may combine visual imaging inspection and an electronic sensing such as voltage imaging, electron beam sensing or charge sensing, in which the potential defect information obtained by the visual inspection system is combined with the potential defect information obtained by the electronic sensing system to produce a defect report. One or more high-resolution visual cameras are scanned over a stationary plate, and the image data from the camera(s) is processed to detect potential defects. A high-resolution electronic sensing system examines the stationary plate, and the image data from the sensor(s) is processed to detect potential defects. The potential defects from the visual image data and electronic sensing image data are processed to produce the final defect information.

Abstract: A method of detecting thin film transistor (TFT) defects in a TFT-liquid crystal display (LCD) panel, includes, in part, applying a stress bias to the TFTs disposed on the panel; and detecting a change in electrical characteristics of the TFTs. The change in the electrical characteristics of the TFTs may be detected using a voltage imaging optical system or an electron beam. The panel temperature may be varied while the bias stress is being applied. The change in the electrical characteristics is optionally detected across an array of the TFTs.

Abstract: A method of detecting thin film transistor (TFT) defects in a TFT-liquid crystal display (LCD) panel, includes, in part, applying a stress bias to the TFTs disposed on the panel; and detecting a change in electrical characteristics of the TFTs. The change in the electrical characteristics of the TFTs may be detected using a voltage imaging optical system or an electron beam. The panel temperature may be varied while the bias stress is being applied. The change in the electrical characteristics is optionally detected across an array of the TFTs.

Abstract: A method of manipulating a substrate comprising gripping a lower surface of the substrate with a master vacuum gripper mounted on a first motorized stage. The master vacuum gripper is adapted to rotate about a Z-axis. The method also includes gripping the lower surface of the substrate with a slave vacuum gripper mounted on a second motorized stage. The slave vacuum gripper is also adapted to rotate about the Z-axis. The method further includes actuating the second motorized stage in a first direction, thereby causing the slave vacuum gripper to move laterally in both the first direction and a second direction and the master vacuum gripper to rotate about the Z-axis.

Abstract: A method and apparatus for optically inspecting a display employs sub-pixel accuracy for each primary color to take into account angle of rotation. The method includes capturing images of a display with R×S sensors; determining sets of sensor coordinates mapping to a pixel, determining multiple misalignment angles between the pixel on the display and the R×S sensors, determining multiple x scaling ratios, determining multiple weighting factors associated with R×S sensors in response to the corresponding multiple misalignment angle and the corresponding multiple x and y scaling ratios, determining multiple luminance values for R×S sensors, determining multiple total luminance values in response to the weighting factors and the luminance values, forming scaled images including first and second luminance values, and inspecting the scaled image to identify potential defects of the pixel on the display.

Abstract: A tracking auto-focus system maintains a microscope pointed at a TFT array continuously in focus so as to eliminate the auto-focusing time that would otherwise be required. The tracking auto-focus system includes, in part, a microscope Z actuator, an auto-focus sensor, an analog-to-digital converter (ADC), a signal conditioner, a digital proportional integrating and differentiating (PID) controller, and a digital-to-analog converter. The actuator adjusts the distance between the microscope's objective lens and the target and includes, in part, an amplifier, a linear motor, and a linear encoder which provides positional feedback. The auto-focus sensor together with the ADC and signal conditioner continuously monitor and detect the distance between the microscope's objective lens and the target and supply the measured distance to the amplifier. The PID controller together with the DAC stabilizes the distance separating the microscope's objective lens and the target to maintain the best focus.

Abstract: A chuck adapted to support a substrate includes an array of glass bars spaced apart and each having a number of holes in its supporting surface. The holes in the supporting surfaces are connected to a common conduit that is supplied with air to provide an air cushion to support the substrate during loading and positioning operations. Scrubbers in contact with one or more edges of the substrate are used to locate the substrate precisely relative to a mechanical reference. After the substrate is positioned at the desired location, the common conduit is separately supplied with vacuum to provide a suction force to hold the substrate to the chuck. The array of glass bars are designed to operate in conjunction with a multi-light backlight system that provides uniform illumination for areas of the substrate that are supported above a glass bar as well as for areas of the substrate that are positioned between the glass bars.

Abstract: In accordance with the present invention, a first shorting bar drives the data lines of a TFT array having integrated gate driver circuitry. Another set of shorting bars drive the corresponding terminals of the gate driver circuitry. The pixel voltages are measured after all the pixels are charged by the driving signals applied to the shorting bars. Gate voltages are progressively applied to the gate lines by the gate driver integrated circuit (IC) via the set of shorting bars that, in turn, are driven by clock signals received from one or more pattern generators. Voltages are concurrently applied to the data lines which are connected together by the first shorting bar. The application of voltages generates a display pattern that is subsequently compared to an expected display pattern. By comparing the resulting display pattern and the expected display pattern, possible defects are detected.

Abstract: The position of a substrate's edge is detected using a substrate alignment system that includes, in part, a light source, an optical module adapted to receive a light emanating from the light source to form a multi-dimensional light beam; and an array sensor positioned at a focal plane of the optical module and oriented substantially perpendicular to the sample's edge. The substrate alignment system detects the substrate's edge position as soon as the substrate is loaded and placed within the capture range of the linear array sensor. As long as the substrate's edge position is within the capture range, the substrate does not have to be moved to determine its position relative to the tool's coordinate space. The capture range is substantially larger than the position accuracy required. The sensor array includes a multitude of sensors disposed along one or more rows.

Abstract: In an inspection system for planar objects having periodic structures, programmable optical Fourier filtering in the focal plane of a telecentric lens system is used to directly identify physical phenomena indicative of non-periodic defects. Lens assemblies and a coherent optical source are used to generate and observe a spatial Fourier transform of a periodic structure in the Fourier plane. Optical Fourier filtering (OFF) is performed in the focal plane using an electrically programmable and electrically alignable spatial light modulator. The spatial light modulator with high signal to noise ratio is electrically reconfigurable according to a feedback-driven, filter construction and alignment algorithm. The OFF enhances any non-periodic components present in the Fourier plane and final image plane of the object. A system having a plurality of inspection channels provides high-throughput inspection of objects with small non-periodic defects while maintaining high detection sensitivity.

Abstract: A modular split-axis stage is used to inspect and/or repair large flat glass media suitable for LCD/TFT applications. Low-precision air table sections are detachably mounted to a centrally located, high-precision granite inspection/repair section. Glass media held by a vacuum contact is transported on air cushions from the up-web air table to the central inspection/repair section. Vacuum nozzles integrated with porous medium pads precisely control the height of the flexible media above the central section during inspection or repair. Embodiments includes structures in which the media is either stationary or moving during inspection/repair. A first media can be loaded/unloaded while a second media is undergoing inspection or repair in a pipelined operational mode.

Abstract: Each sensor of a linear array of sensors includes, in part, a sensing electrode and an associated feedback circuit. The sensing electrodes are adapted to be brought in proximity to a flat panel having formed thereon a multitude of pixel electrodes in order to capacitively measure the voltage of the pixel electrodes. Each feedback circuit is adapted to actively drive its associated electrode via a feedback signal so as to maintain the voltage of its associated electrode at a substantially fixed bias. Each feedback circuit may include an amplifier having a first input terminal coupled to the sensing electrode and a second input terminal coupled to receive a biasing voltage. The output signal of the amplification circuit is used to generate the feedback signal that actively drives the sensing electrode. The biasing voltage may be the ground potential.

Abstract: A repair system for flat panel display (FPD) substrates performs a number of operations, such as automatic image capture and processing, automatic defect classification, automatic repair classification, and repair macro (instruction) generation software. Defect classification, repair classification, and repair macro generation are based on an open architecture and can address any number of use-cases through the use of multi-tiered classifiers, and thus a wide variety of panel designs may be repaired within a single repair tool. The multi-tiered set of classifiers, e.g., defect classifier, repair classifier, enables an efficient decision-making repair process with capability for customization. The multi-tiered classifiers are optionally extended to support statistical learning (both online & batch) and active learning, in the context of a supporting database of defects and associated tools.

Abstract: A tracking auto-focus system maintains a microscope pointed at a TFT array continuously in focus so as to eliminate the auto-focusing time that would otherwise be required. The tracking auto-focus system includes, in part, a microscope Z actuator, an auto-focus sensor, an analog-to-digital converter (ADC), a signal conditioner, a digital proportional integrating and differentiating (PID) controller, and a digital-to-analog converter. The actuator adjusts the distance between the microscope's objective lens and the target and includes, in part, an amplifier, a linear motor, and a linear encoder which provides positional feedback. The auto-focus sensor together with the ADC and signal conditioner continuously monitor and detect the distance between the microscope's objective lens and the target and supply the measured distance to the amplifier. The PID controller together with the DAC stabilizes the distance separating the microscope's objective lens and the target to maintain the best focus.

Abstract: A PDLC modulator is fabricated using at least one a selection of specially-formulated UV curable organic hard coatings as a protective layer on the exposed side of polyester (Mylar) film. The hard coatings of various related types show good adhesion on a polyester film substrate, superior hardness and toughness, and have a slippery top surface, which minimizes unnecessary wear. The coating as applied on the modulator surface significantly reduces scratch damage on modulators caused by unexpected particles on the panels under test. In addition, the slip surface will reduce stickiness to particles and therefore also reduce the possibility of panel damage.

Abstract: In an inspection system for planar objects having periodic structures, programmable optical Fourier filtering in the focal plane of a telecentric lens system is used to directly identify physical phenomena indicative of non-periodic defects. Lens assemblies and a coherent optical source are used to generate and observe a spatial Fourier transform of a periodic structure in the Fourier plane. Optical Fourier filtering (OFF) is performed in the focal plane using an electrically programmable and electrically alignable spatial light modulator. The spatial light modulator with high signal to noise ratio is electrically reconfigurable according to a feedback-driven, filter construction and alignment algorithm. The OFF enhances any non-periodic components present in the Fourier plane and final image plane of the object. A system having a plurality of inspection channels provides high-throughput inspection of objects with small non-periodic defects while maintaining high detection sensitivity.

Abstract: A method for inspecting a display panel includes capturing images of a portion of a plurality of display panels having display elements with an image acquisition device having sensor elements, each image comprising an image of approximately a first number of display elements captured with approximately a second number of sensor elements, the first number different from the second number, each image including a Moiré artifact pattern, combining the images of the portion of the plurality of display panels to form a reference image including a Moiré artifact pattern reference, capturing a sample image of a portion of a sample display panel having display elements with the image acquisition device, the sample image comprising an image of approximately the first number of display elements on the sample display captured with approximately the second number of sensor elements, the sample image including a sample Moiré artifact pattern, combining the sample image with the reference image to inhibit the sample Moiré a

Abstract: In an inspection system for electrical and electro-optical inspection of TFT-LCD panels, a fine resolution area imaging camera with a pulse illumination source disposed to scan the region and operative capture images of the region illuminated with pulses of short illumination and automatically maintained in focus while continuously scanning in order to resolve points of defects.

Abstract: A modular split-axis stage is used to inspect and/or repair large flat glass media suitable for LCD/TFT applications. Low-precision air table sections are detachably mounted to a centrally located, high-precision granite inspection/repair section. Glass media held by a vacuum contact is transported on air cushions from the up-web air table to the central inspection/repair section. Vacuum nozzles integrated with porous medium pads precisely control the height of the flexible media above the central section during inspection or repair. Embodiments includes structures in which the media is either stationary or moving during inspection/repair. A first media can be loaded/unloaded while a second media is undergoing inspection or repair in a pipelined operational mode.

Abstract: A PDLC modulator is fabricated using at least one of a selection of specially-formulated UV curable organic hard coatings as a protective layer on the exposed side of polyester (Mylar) film. The hard coatings of various related types show good adhesion on a polyester film substrate, superior hardness and toughness, and have a slippery top surface, which minimizes unnecessary wear. The coating as applied on the modulator surface significantly reduces scratch damage on modulators caused by unexpected particles on the panels under test. In addition, the slip surface will reduce stickiness to particles and therefore also reduce the possibility of panel damage.