Back-lit liquid crystal display, in particular for use as a display module behind the operating panel of a large domestic appliance

• US 20050083449A1
• Filed: 11/29/2004
• Published: 04/21/2005
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: Diehl AKO Stiftung & Company KG
• Original Assignee: Diehl AKO Stiftung & Company KG
• Inventors: Morsch, Norbert
• Granted Patent: US 7,483,092 B2
• Time in Patent Office: Days
• US Class Current: 349/58
• CPC Class Codes: A47L 15/4293 Arrangements for programme selection, e.g. control panels; Indication of the selected programme, programme progress or other parameters of the programme, e.g. by using display panels
• CPC Class Codes: D06F 34/32 characterised by graphical features, e.g. touchscreens
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 2201/503 Arrangements improving the resistance to shock

Abstract

A display module has a back-lit liquid crystal cell and is used in particular in an operating panel of a large domestic appliance. A particularly inexpensive structure is afforded in which the height-wise dimension of the module is affected by bracing a frame that mounts the liquid crystal cell and a light-guide panel under it against a circuit carrier whose surface on which the light-guide panel rests is in the form of a reflector surface. The circuit carrier has integrated conductor tracks and a receiving device formed therein for the light-guide panel. The frame can be fitted over the sandwich structure of the light-guide panel and the liquid crystal cell. Fixing as between the frame and the circuit carrier is effected by resiliently latching barb hook members, and with through-engagement of positioning studs or pillars. The free ends of which are subjected to hot peening for fixing the position thereof.

Claims

1. A back-lit liquid crystal display, comprising:

a circuit carrier;

a liquid crystal cell electrically and mechanically connected to said circuit carrier;

a light-guide panel disposed under said liquid crystal cell and through which light passes therethrough transversely with respect to a viewing direction, said light-guide panel having a limb and a first reflector surface;

a frame accommodating said liquid crystal cell and said light-guide panel, said frame connected in a force-locking and/or a form-locking relationship to said circuit carrier;

said frame, said circuit carrier, said liquid crystal cell, and said light-guide panel defining a display module for use behind an operating panel of a large domestic appliance;

said circuit carrier having a first surface oriented towards said light-guide panel and thus opposite to a second surface for fitment with component elements, said first surface functioning as a second reflector surface; and

light sources radiating the light through said circuit carrier into said limb of said light-guide panel and towards said first reflector surface for light deflection and thereby for lateral light entry into said light-guide panel.

2. The liquid crystal display according to claim 1, further comprising a peripherally extending, compressible spacer inserted between said liquid crystal cell and said light-guide panel.

3. The liquid crystal display according to claim 1, wherein:

said circuit carrier has a flexuarlly elastic tongue region; and

said frame has barb hooks, engaging through said circuit carrier, to said flexurally elastic tongue region of said circuit carrier.

4. The liquid crystal display according to claim 1, further comprising:

studs for positioning said frame relative to said circuit carrier; and

a collar extending around said frame, for positioning said frame relative to said circuit carrier.

5. The liquid crystal display according to claim 4, wherein said studs are formed from a hot-peenable plastic material and are formed on said collar or on said circuit carrier.

6. The liquid crystal display according to claim 1, wherein said circuit carrier is injected molded using molded interconnecting device technology;

wherein said second reflector surface is disposed behind said light-guide panel; and

further comprising a receiving device on which said second reflector surface is formed.

7. The liquid crystal display according to claim 1, wherein said circuit carrier and said frame are formed as a single injection molded piece with a film hinge connecting said circuit carrier to said frame in a pivotal hinge-like manner.

8. The liquid crystal display according to claim 1, further comprising studs for positioning said frame relative to said circuit carrier.

9. The liquid crystal display according to claim 1, further comprising a collar extending around said frame, for positioning said frame relative to said circuit carrier.