Surface inspection system

• US 6,850,636 B1
• Filed: 05/25/2000
• Issued: 02/01/2005
• Est. Priority Date: 05/25/1999
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation, The Consumer Financial Network, Inc. (Scient, Inc.)
• Original Assignee: Nichia Corporation
• Inventors: Yabe, Tomoyoshi
• Primary Examiner(s): Dastouri, Mehrdad
• Assistant Examiner(s): KIBLER, VIRGINIA M
• Application Number:
  US09/578,038
• Time in Patent Office: 1,713 Days
• Field of Search: 382/107, 382/108, 382/141, 382/151, 382/152, 382142-145, 382/147, 348/87, 348/94, 348/95, 348/134
• US Class Current: 382/141
• CPC Class Codes: G01N 21/8901 Optical details; Scanning details per se G02B
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

An inspection system which enables even the production control section located at a remote place to trace and inspect the changing process of the external appearance, after undergoing through each manufacturing process, of a great number of work boards that have been placed on a continuous work line. According to this inspection system, the moving velocity of work board being transferred by means of a transfer roller is measured by a rotary pulse encoder, and the sampling rate of a CCD line sensor camera is controlled to obtain a surface image data of the moving work board.

Claims

1. A surface inspection system for work boards passing through a plurality of manufacturing processes being transferred by a transferring roller, comprising:

a detecting means for detecting entry and exit of each work board into and out of each manufacturing process;

a time-measuring means for measuring times when the entry and exit of each work board are detected by said detecting means;

a determining means for determining whether each work board exits out of each manufacturing process at a scheduled exit time calculated based on the entry time measured by said time-measuring means;

line sensors for one dimensionally acquiring image data related to colors of an elongated work board having exited out of each manufacturing process in lines perpendicular to the moving direction of the work board, each line sensor comprising two types of image data sampling means, one for an odd-number sampling line and the other for an even-number sampling line;

a velocity-measuring means for measuring in real time the rotational velocity of the transferring roller on each data sampling position of the line sensor;

a sampling control means for controlling timing of the image data sampling of said line sensor in the direction of board movement and on the basis of the moving velocity of the work board measured by said velocity-measuring means;

an image-composing memory for forming a two-dimensional image of the work board by sequentially combining odd line data and even-line data from the line sensor;

a controlling means to correct the image data based on degree of slant of the work board;

an identifying means for identifying the work board and the image data thereof based on a process number representing each manufacturing process, and on times of entry and exit of the work board into and out of the process measured by said time-measuring means; and

a transmitting means for assigning each work board its own transmission channel for sequentially transmitting images of the board on each manufacturing process, assembling said image data into a transmission packet and transmitting said transmission packet.

2. A surface inspection system as in claim 1, wherein slant correction is accomplished by an affine transformation based on the angle of slant as determined by the following equation:

θ

=cos−

1 (A₀/A′

)

wherein θ

equals the angle of slant, A₀ equals the number of pixels corresponding to the width of the work board and A′

equals the number of pixels forming the board on the data sampling line.