System and method for developing three-dimensional surface information corresponding to a contoured glass sheet

A system for fabricating generally rectangular, curved glass sheets having a surface of interest with a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, the system including one or more processing stations and one or more conveyors for conveying a glass sheet from station to station during processing, one of the processing stations including an apparatus for acquiring surface data from one of the surfaces of a glass sheet and developing a surface definition of the glass sheet as the glass sheet is conveyed in a first direction generally parallel to the first dimension of the glass sheet, the apparatus comprising;

• at least two displays, each display projecting a preselected contrasting pattern,
• at least two cameras, each one of the cameras being uniquely paired with one of the displays, wherein each display and camera pair are mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet such that the camera detects the reflected image of the pattern projected on the surface of the glass sheet from its associated display, and wherein each of the display and camera pairs are spaced apart from each other at least in a second direction across the second dimension of the glass sheet such that each camera detects the reflected image of the pattern projected on the surface of the glass sheet from only its associated display, and wherein the patterns detected by the cameras together cover the entire surface in the direction of the second dimension of the glass sheet;
• and
• a programmable control including at least one processor programmed to execute logic for controlling each of the cameras to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction, and logic for analyzing and combining the data acquired by the cameras to construct surface data representative of the surface of the glass sheet.

A system for acquiring surface data from one of the surfaces of a generally rectangular, curved glass sheet having a surface of interest with a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, and developing a surface definition of the glass sheet, the system comprising:

• a conveyor for conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet;
• at least one display projecting a preselected multi-frequency, non-repeating contrasting pattern on the surface of the glass sheet,
• a camera associated with each of the at least one displays and mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet such that the camera detects the reflected image of the pattern projected on the surface of the glass sheet from the associated display;
• and
• a programmable control including at least one processor programmed to execute logic for controlling each of the cameras to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction, and logic for analyzing and combining the data acquired by the cameras to construct surface data representative of the surface of the glass sheet.

A system for acquiring surface data from one of the surfaces of a generally rectangular, curved glass sheet having a surface of interest with a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, and developing a surface definition of the glass sheet, the system comprising:

• a conveyor for conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet;
• at least one display projecting a preselected contrasting pattern on the surface of the glass sheet,
• a camera associated with each of the at least one displays and mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet such that the camera detects the reflected image of the pattern projected on the surface of the glass sheet from the associated display;
• and
• a programmable control including at least one processor programmed to execute logic for controlling each of the cameras to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction, and logic for analyzing and combining the data acquired by the cameras to construct surface data representative of the surface of the glass sheet,
• wherein the logic for analyzing and combining the data acquired by the cameras to construct surface data representative of the surface of the glass sheet includes at least:
• logic for developing, for each pixel in in the viewing area of the camera for each acquired image, a mapping vector that defines where the reflected ray projects from the camera origin to the associated display;
• and
• logic for developing, for each pixel in the viewing area of the camera for each acquired image, the elevation value, s, of the point, by simultaneously solving (1) the geometric optical equation and (2) the differential geometry equation, using the mapping vector.

A method for acquiring surface data from a curved glass sheet and developing a surface definition of the glass sheet, the glass sheet having a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, the method including at least the steps of:

• conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet;
• projecting a preselected contrasting pattern from each of at least two displays onto the surface of the glass sheet
• providing at least two cameras, each one of the cameras being uniquely paired with one of the displays, wherein each display and camera pair are mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet for detecting the reflected image of the pattern projected on the surface of the glass sheet from its associated display, and wherein each of the display and camera pairs are spaced apart from each other at least in a second direction across the second dimension of the glass sheet such that each camera detects the reflected image of the pattern projected on the surface of the glass sheet from only its associated display, and wherein the patterns detected by the cameras together cover the entire surface in the direction of the second dimension of the glass sheet;
• controlling each of the cameras to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction;
• and
• analyzing and combining the data acquired by the cameras to construct surface data representative of the surface of the glass sheet.

A method for acquiring surface data from one of the surfaces of a generally rectangular, curved glass sheet having a surface of interest with a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, and developing a surface definition of the glass sheet, the method including at least the steps of:

• conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet;
• projecting a preselected contrasting pattern from a display onto the surface of the glass sheet;
• providing a camera paired with the display, wherein the display and camera pair are mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet for detecting the reflected image of the pattern projected on the surface of the glass sheet from the display, and wherein the pattern detected by the camera covers the entire portion of interest on the surface in the direction of the second dimension of the glass sheet;
• controlling the camera to acquire at least one image of the reflected pattern on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction;
• and
• analyzing and combining the data acquired by the camera to construct surface data representative of the surface of the glass sheet, including at least the steps of
• developing, for each pixel in in the viewing area of the camera for each acquired image, a mapping vector that defines where the reflected ray projects from the camera origin to the associated display, and
• developing, for each pixel in the viewing area of the camera for each acquired image, the elevation value, s, of the point, by simultaneously solving (1) the geometric optical equation and (2) the differential geometry equation, using the mapping vector.