Browse Prior Art Database

Image Acquisition System

IP.com Disclosure Number: IPCOM000062040D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 3 page(s) / 35K

Publishing Venue

IBM

Related People

Davidson, WH: AUTHOR [+2]

Abstract

An optical spot scanner captures a pattern displayed on a color CRT screen. The colored spots captured are split into three primary colors to produce data for software analysis. By selectively sampling a raster scan, the pattern displayed may be tested. The system has applications in manufacturing line testing, e.g., CRT, other type of display or keyboards, or robotics control using the same hardware with only software changes. This disclosure is concerned with the remote acquisition of color image data from a range of products using a technique suitable for a manufacturing environment and is for use on automated lines capable of handling a variety of products. It is desirable that the full product range can be handled without any mechanical or optical changes to the system, i.e.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 51% of the total text.

Page 1 of 3

Image Acquisition System

An optical spot scanner captures a pattern displayed on a color CRT screen. The colored spots captured are split into three primary colors to produce data for software analysis. By selectively sampling a raster scan, the pattern displayed may be tested. The system has applications in manufacturing line testing, e.g., CRT, other type of display or keyboards, or robotics control using the same hardware with only software changes. This disclosure is concerned with the remote acquisition of color image data from a range of products using a technique suitable for a manufacturing environment and is for use on automated lines capable of handling a variety of products. It is desirable that the full product range can be handled without any mechanical or optical changes to the system,
i.e., the system is capable of handling multiple products with only software changes. The image acquisition system is illustrated in the diagram. A single spot scanner 1 uses orthogonally mounted mirrors each driven by a galvanometer-type motor. A beam splitter and three photomultipliers 2 produces signals for the three primary colors (blue, red and green) which are fed to software-controlled analyzer 3. CRT screen 4 displays a text pattern, each cross representing an area in which there should be a display. Spot scanner 1 scans screen 4 in a raster along lines 6. Software analysis samples the blue, red and green signals, selecting only those areas of the screen which should be displayed. By comparison of parameters derived from the displayed image with the desired engineering specification, the display is tested. Spot scanner 1 and beam splitter 2 are available commercially in which a simple optical system with one moving element (mounted on a linear translator) maintains constant magnification whilst correcting for the varying path length as the mirror angle(s) vary. Also geometric distortion may be handled by software acting on the mirror position control. An advantage of the system described is that the resolution is programmable. With high resolution, a single pel (picture element) on a CRT screen may be captured or coarse image sampling may be accomplished by increased mirror movement between samples. In addition, screen areas of no interest may be ignored. Modes of operation are listed below: 1. RASTER SCAN In this mode, one mirror moves continuously to sweep the sampling spot along one axis of the screen or target. The second mirror would then increment, and the first mirror would either sweep in the reverse direction or reset to its starting point and then sweep in the same direction as before. This sequence would repeat until the required raster has been generated. There are three main techniques for driving the mirrors: a. START - STOP This is the simplest to achieve, the mirror is deflected to the next point of interest and, once there, a sample is taken. In most cases this would be unacceptably slow. b. CONSTANT VELOCITY T...