Browse Prior Art Database

APPLYING POLARIZERS TO LIQUID CRYSTAL DISPLAYS

IP.com Disclosure Number: IPCOM000025310D
Original Publication Date: 1984-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 112K

Publishing Venue

Xerox Disclosure Journal

Abstract

For increased contrast, ambiently lighted liquid crystal displays (LCDs) need to be viewed through polarizers which usually are attached to the front and rear surfaces of the display. The polarizers are formed from plastic sheet approximately 10 mil thick with a layer of contact adhesive on one side protectively covered by a strippable film.

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 56% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

APPLYING POLARIZERS TO LIQUID CRYSTAL DISPLAYS
Ivo P. Gates

Proposed Classification
U.S. C1. 350/158 Int. CI. G02b 1/24

FIG. I

/6

F/G. 2

f"

30

f

FIG. 3

Volume 9 Number 4 July/August 1984 759

[This page contains 1 picture or other non-text object]

Page 2 of 2

APPLYING POLARIZERS TO LIOUID CRYSTAL DISPLAYS (Cont'd)

For increased contrast, ambiently lighted liquid crystal displays (LCDs) need to be viewed through polarizers which usually are attached to the front and rear surfaces of the display. The polarizers are formed from plastic sheet approximately 10 mil thick with a layer of contact adhesive on one side protectively covered by a strippable film.

To attain a smooth, unbroken contact surface between the LCD and polarizers poses some problems, as standard methods often cause breakage of the LCDs or leave bubbles trapped under the polarizers. One solution is to apply the polarizers by utilizing a standard silk screen printer. Silk screen printers are normally found in facilities used for the manufacture of LCDs, so the machine can he used in a dual capacity of depositing perimeter seals, etc. and applying polarizers.

No modification of the silkscreen printer is needed to apply the polarizers, but for scaling up for quanity production,.an add-on auxilliary unit 30 could be attached to the printer which would not interfere with its prime function.

In Figure 1, a pre-cut strip of polarizer 12 with the contact adhesive side down and the strippable film removed, is attached to the underside of the printer's screen 14 using the pattern of the perimeter seal as an aid to positioning. The LCD 1 I) is now placed on the vacuum workplate 16 using the alignment pins (not shown) for positioning, so that it will be directly under the polarizer when the minter 20 is started.

The gap "h" between the screen and top of the LCD is adjusted to about 50 mils and the printer is operated in the off contact mode. Referring to Figure 7, the squeegee 18 comes dow...