Readable display stucture - Patent 0495616

(19)

(11)

EP 0 495 616 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	03.02.1993 Bulletin 1993/05

(43)	Date of publication A2:
	22.07.1992 Bulletin 1992/30

(21)	Application number: 92300290.1

(22)	Date of filing: 14.01.1992

(51)	International Patent Classification (IPC)⁵: G01D 11/28, B60Q 3/04, G09F 9/35, G09F 13/04

(84)	Designated Contracting States:
	CH DE ES FR GB IT LI

(30)

Priority:

15.01.1991 US 641184

(71)	Applicant: ILLINOIS TOOL WORKS INC.
	Glenview, Illinois 60025-5811 (US)

(72)	Inventor:
	Tannas, Lawrence E., Jr. Orange, California 92666 (US)

(74)	Representative: Rackham, Stephen Neil
	GILL JENNINGS & EVERY, Broadgate House, 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)

(56)

References cited: :

(54)	Readable display stucture

(57) A display structure which is readable even in direct sunlight includes a layered structure formed of a reflective element (42), an LED light source (18), a coloured filter (16), a legend plate (14), and a liquid crystal shutter (12). The reflective element (42) is positioned behind the LED light source (18). The light source is formed of an LED array (26) having a diffusion medium (28) disposed in front of the LED array (26) for scattering light when energized. The liquid crystal shutter (12) permits displayable information on the legend plate (14) to be viewed only when the LED array (26) and the liquid crystal shutter (12) are energized. The reflective element (42) and the diffusion medium (28) reflect and scatter incident sunlight which has passed through the liquid crystal shutter (12), legend plate (14) and coloured filter (16). This light is then reflected back through the coloured filter (16) and legend plate (14) and out the liquid crystal shutter (12). The coloured filter (16) is preferably selected to have certain spectral transmission characteristics. As a result, the contrast of the displayable information on the legend plate is enhanced and is unaffected by washout when viewed in an area of incident sunlight.

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