METODO E APARELHO PARA A PRODUCAO DE UMA IMAGEM OPTICA SECUNDARIA

• Main Author: CHARLES N. HARWARD
• Format: Patent
• Language: Portuguese
• Published: 12.06.1990
• Edition: 5
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CALCULATING; COMPUTING; COUNTING; CRYPTOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DISPLAY; EDUCATION; FREQUENCY-CHANGING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SEALS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

Features of an input image (10) having a predetermined brightness level are optically enhanced in the output image (34 min ) relative to other parts of the input image having a brightness level greater or less than the predetermined level. The input image (10) is displayed on a liquid crystal display (20) by conventional means including a video camera (12) with associated exposure and brightness controls (36). Light from a light source (22), polarized by a first polarizer (24), illuminates the display (20). Light transmitted by the display is polarized by a second polarizer (28) and displayed as the output image (34 min ). By controlling the angle of the polarization axes (26,30) of the polarizers (24,28) and the brightness of the input image (10), selected features of the input image may be made brighter or darker than other features of the input image in the output image (34 min ). Such method and apparatus has particular application in inspection of printed goods where selected portions of a printed area may be made to stand out to allow inspection for accuracy and alignment of the printing.