Abstract: An optical position encoder employs spatial filtering of diffraction orders other than +/?1st diffraction orders for greater accuracy. The encoder includes a light source, a scale including a diffractive scale pattern, an optical detector adjacent to the scale, and first and second spaced-apart diffraction gratings between the light source and the scale. The gratings and scale are configured to spatially separate +/?1st diffraction orders from other diffraction orders and to direct the +/?1st diffraction orders along respective optical paths. The optical paths diverge from the first grating to respective locations on the second grating that are separated by more than the beam width of the source light beam. The optical paths further converge from the locations on the second grating to an area of the scale adjacent to the detector, and then extend from the area of the scale to the detector to create an interference pattern as a function of the relative position between the scale and the light source.

Abstract: Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Abstract: An array of sensitive pixel elements is configured to generate signals representative of sensed light that is associated with writing being done by a user, and an optical system concentrates light from a light source across a section of the array of sensitive pixel elements, the signals being useful to compute a subpixel measurement of a position of the light source.

Abstract: A method and system for protecting digital images copied from a video RAM, including the steps of transmitting stored pixel data from a computer memory to a video RAM, identifying protected pixel data within the stored pixel data, modifying the stored pixel data, thereby generating modified pixel data within which individual pixel datum is recognizable as being protected or unprotected, and, in response to pixel data being copied from the video RAM, replacing individual pixel datum copied from the video RAM, that is protected, with substitute pixel datum.

Abstract: A flexible optical marker is applied to an optical scale substrate to make an optical scale assembly for an optical position encoder. The marker may be a limit marker, index marker, or other type of marker. The marker substrate may be a plastic film such as polyester, singulated from a “recombine” roll created by a web process. The marker has a microstructured pattern on one surface that is covered with a reflective metal coating. The marker also has an adhesive layer and is affixed to the optical scale substrate by a process of aligning the marker to an edge of the scale and then applying pressure to the upper surface of the marker. The marker may be applied with a handle portion that is separated from the marker after the marker is affixed. The marker may be especially useful with a flexible scale substrate such as a metal tape substrate.

Abstract: Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: An encoder calculates position error values and applies compensation values to encoder position measurements in-situ. The encoder includes a scale and a multi-section detector for detecting a spatially periodic pattern, such as an optical interference pattern, produced by the scale. The detector includes spatially separated first and second sections. A signal processor estimates respective phase values from detector sections and calculates a phase difference reflecting a spatial position error in the scale. A compensation value is calculated from the phase difference and included in the estimate of the scale position to compensate for this spatial position error. The compensation values may be calculated and used on the fly, or calculated and saved during an in-situ calibration operation and then utilized during normal operation to compensate uncorrected measurements.

Abstract: Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Abstract: Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: An optical encoder includes an optical source, a scale, an optical detector and signal processing circuitry. The scale is operative with a light beam from the source to generate an optical pattern such as a line pattern extending in an X direction of relative movement between the scale and the source. The detector generates analog detector output signals indicative of the location of the optical pattern on the detector in an alignment direction orthogonal to the X direction. The detector may include two bi-cell elements spaced apart in the X direction, each element including two cells of complementary shape, such as a sharks-tooth. The signal processing circuitry operates in response to the detector output signals to generate an alignment value indicating a polarity and a magnitude of misalignment between the detector and the scale in the alignment direction.

Abstract: An encoder calculates position error values and applies compensation values to encoder position measurements in-situ. The encoder includes a scale and a multi-section detector for detecting a spatially periodic pattern, such as an optical interference pattern, produced by the scale. The detector includes spatially separated first and second sections. A signal processor estimates respective phase values from detector sections and calculates a phase difference reflecting a spatial position error in the scale. A compensation value is calculated from the phase difference and included in the estimate of the scale position to compensate for this spatial position error. The compensation values may be calculated and used on the fly, or calculated and saved during an in-situ calibration operation and then utilized during normal operation to compensate uncorrected measurements.

Abstract: Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.

Abstract: A method for protecting digital images distributed over a network, including the steps of receiving a request from a client computer running a network browser, for an original layout page containing references to digital images therein, parsing the original layout page for the references to digital images, generating a modified layout page from the original layout page by replacing at least one of the references to digital images in the original layout page with references to substitute data, and sending the modified layout page to the client computer. A system is also described and claimed.