Flex circuit board for liquid crystal display

• US 5,436,745 A
• Filed: 02/23/1994
• Issued: 07/25/1995
• Est. Priority Date: 02/23/1994
• Status: Expired due to Fees

• Current Assignee: First Chicago/NBD Bank N.A., InnoLux Corporation
• Original Assignee: OIS Optical Imaging Systems, Inc. (KOCH Industries Incorporated)
• Inventors: Voisin, Paul A., Bradford, Brian K. III
• Primary Examiner(s): Gross, Anita Pellman
• Assistant Examiner(s): MILLER, CHARLES LELAND
• Application Number:
  US08/200,670
• Time in Patent Office: 517 Days
• Field of Search: 359/88, 359/83, 359/87, 359/62, 257/666, 257/672
• US Class Current: 349/58
• CPC Class Codes: G02F 1/133382 Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/052 Branched
• CPC Class Codes: H05K 2201/053 Tails
• CPC Class Codes: H05K 2201/09027 Non-rectangular flat PCB, e.g. circular
• CPC Class Codes: H05K 2201/10136 Liquid Crystal display [LCD]
• CPC Class Codes: H05K 2201/10681 Tape Carrier Package [TCP]; Flexible sheet connector
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits

Abstract

An active matrix liquid crystal display assembly including a flex circuit for interfacing substantially all of the row and column address lines of the display panel with a display output controller. The flex circuit is preferably made of two planar sheets laminated to one another, the first flex circuit sheet interfacing the row address lines with the display output controller and the second sheet interfacing the column address lines of the active matrix with the controller. The flex circuit includes a plurality of extension members, each extension member being electrically adhered to a driver TAB mounted to a peripheral side of the display panel.

Claims

1. An active matrix liquid crystal display assembly comprising:

a planar active matrix display panel with four sides on the periphery thereof, said display panel including a plurality of row and column address lines for driving a matrix array of pixels, each pixel including a liquid crystal layer and means for applying a voltage thereto; and

a flex circuit for electrically interfacing substantially all of said row and column address lines with a display output controller, said flex circuit being ring-shaped and disposed adjacent each of said four peripheral sides of said planar display panel, and wherein said flex circuit includes a planar ring portion having a plurality of conductive traces disposed thereon, said ring portion defining a plane substantially parallel to the plane defined by said planar display panel.

2. The display assembly of claim 1, wherein said ring portion is mounted adjacent each of said four peripheral sides of said display panel, said flex circuit defining a viewing area of said panel through which light is selectively allowed to pass.

3. The display assembly of claim 2 wherein said flex circuit further includes a plurality of extension members connected to said ring portion, said extension members being electrically connected to a corresponding plurality of driver TABS mounted on two of said four peripheral sides of said display panel and, wherein said display panel defines a first plane and said extension members define a plurality of planes each substantially perpendicular to said first plane, and said driver TABS have driver chips affixed thereto and are attached to said planar display panel, said TABS also defining planes substantially perpendicular to said first plane.

4. The display assembly of claim 3, wherein at least one of said driver TABS comprises:

a base portion having first, second and third input contact row windows defined therein, said input contact row windows extending substantially parallel to the plane defined by said display panel;

a driver chip or die mounted thereon for controlling the output data of a plurality of conductive output leads, said driver chip and said output leads being disposed on said base portion;

a plurality of input leads defining first, second, and third input contact rows, each of said contact rows including a plurality of electrical contacts disposed on said base portion and crossing over said first, second and third contact row windows respectively, said first and second contact rows being substantially parallel to one another, said first contact row having a greater number of contacts than said second contact row; and

wherein at least some of said contacts of each of said first, second, and third input contact rows are adapted to interface said driver chip or die with a display output controller.

5. The display assembly of claim 4, wherein said first and third input contact rows are substantially parallel to one another, said second and third contact rows defining an elongated axis which is substantially parallel to said first contact row, said second and third contact rows being located on said base portion between said first contact row and said die or driver chip, wherein a plurality of said input leads on said base portion electrically connecting said die or driver chip and said first contact row are disposed and pass between said second and third contact rows, and

wherein said driver TAB further comprises a fourth contact row, said fourth contact row being an output contact row including a plurality of output contacts to be electrically connected to address lines of said display panel.

6. The display assembly of claim 3, wherein said planar ring portion is mounted on the rear planar surface of said display panel so as to define a plane substantially parallel to said first plane, and wherein said ring portion includes at least five trace layers disposed thereon.

7. The display assembly of claim 6, wherein at least one of said extension members includes a tail portion extending therefrom, said tail portion being affixed to a main connector which electrically interfaces said flex circuit with said display output controller.

8. The display assembly of claim 7, further including an extension receiver housing mounted to the rear of said display panel for slidably receiving substantially all of said extension members of said flex circuit.

9. The display assembly of claim 8, wherein said extension receiver housing is ring-shaped and includes a plurality of receiving portions, each receiving portion having two grooves defined therein for receiving opposing edges of one of said extension members.

10. The display assembly of claim 1, further comprising a plurality of driver TABS with driver chips mounted thereon, said driver TABS being affixed to said display panel adjacent at least two of said four peripheral sides, thereby enabling said driver TABS to be electrically connected to corresponding extension members of said flex circuit.

11. The display assembly of claim 10, wherein said driver TABS and said extension members define planes which are substantially perpendicular to the plane defined by said display panel.

12. The display assembly of claim 10, wherein said driver TABS are affixed to all four of said peripheral sides of said planar display panel and said extension members are substantially parallel to and electrically adhered to all of said driver TABS.

13. The display assembly of claim 1, wherein said flex circuit includes first and second flexible planar sheets laminated to one another, said first planar sheet interfacing substantially all of said row address lines with said display output controller, and said second planar sheet interfacing substantially all of said column address lines with said output controller.

14. An active matrix liquid crystal display assembly comprising:

a substantially flat display panel including a matrix array of pixels, a liquid crystal layer, and row and column addressing lines for driving said pixels;

a plurality of driver TABS, each driver TAB having a driver chip and corresponding input and output leads disposed thereon, said driver TABS being affixed to said flat display panel adjacent at least two peripheral sides thereof;

a flex circuit for electrically interfacing all of said driver chips with a display output controller for controlling the output of the display panel, wherein said flex circuit is ring-shaped and is directly connected to all of said driver TABS, said flex circuit electrically interfacing substantially all of said driver chips with said display output controller via at least one main connector.

15. The display assembly of claim 14, wherein said flex circuit includes a planar ring portion disposed on the rear planar surface of said flat display panel, said planar ring portion being substantially parallel to the plane defined by said flat panel, said flex circuit further including a plurality of extension portions defining planes substantially perpendicular to said plane of said flat panel, wherein each of said extension portions is connected to one of said driver TABS and interfaces said one of said driver TABS with said display output controller.