Faceplate bonding process for a visual display unit

• US 5,795,430 A
• Filed: 12/02/1996
• Issued: 08/18/1998
• Est. Priority Date: 12/18/1993
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lowe, Anthony C., Beeteson, John
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): YAO, SAMCHUAN CUA
• Application Number:
  US08/753,898
• Time in Patent Office: 624 Days
• Field of Search: 156/295, 156/151, 156/300, 156/297, 156/391, 156/350, 156/556, 348/824, 313/478, 313/479
• US Class Current: 156/350
• CPC Class Codes: B32B 17/10935 as a preformed layer, e.g. formed by extrusion
• CPC Class Codes: B32B 17/10954 by using an aligning laminating device
• CPC Class Codes: G06F 1/1601 Constructional details related to the housing of computer displays, e.g. of CRT monitors, of flat displays constructional details related to flat displays integrated in a portable computer, e.g. laptop, handheld computer G06F1/1637; constructional details related to television receivers H04N5/64
• CPC Class Codes: G06F 2200/1611 CRT monitor
• CPC Class Codes: H01J 29/86 Vessels; Containers; Vacuum locks
• CPC Class Codes: H01J 9/244 specially adapted for cathode ray tubes H01J9/241, H01J9/26 take precedence
• CPC Class Codes: Y10T 156/1744 Means bringing discrete articles into assembled relationship

Abstract

A method of bonding faceplates (20) to VDU screens is provided in which an adhesive material is dispensed (80) onto a surface of either the faceplate or the VDU (40), the faceplate and the VDU are brought together (90) to force the adhesive material outwards to fill the gap between the surfaces, and the adhesive material layer (41) which is formed is then cured. In a first curing step (100), curing is carried out around the edges of the faceplate to form a seal around the edges. This first step may be carried out in a dedicated positioning tool. A later curing step (120) ensures that all of the adhesive material layer is eventually cured. Positioning (90) in the dedicated tool may use specific reference points on the faceplate and the VDU rather than relying on physical spacers, and may be carried out under servo control of a system for detecting the onset of undesirable gas entrapment conditions within the adhesive layer. The invention is particularly useful for automated or semi-automated bonding of touch-plates to screens to form touch-input displays, with the avoidance of spacers and with the selective, two-stage curing enabling minimising of time in the positioning tool.

Claims

1. Apparatus for attaching a transparent faceplate (20) to a screen of a visual display unit (40), by adhesion of opposed surfaces thereof, comprising:

means for locating reference points on the faceplate (20) and on the visual display unit for precise relative positioning of said surfaces by a positioning tool without the need for the positioning of physical spacers between said surfaces;

means for dispensing (80) an adhesive material onto at least one of said surfaces;

a positioning tool for bringing said surfaces together (90) in a controlled manner using said reference points, such that the opposed surfaces displace the adhesive material outwards towards the edges of said surfaces to form an adhesive layer which fills the gap therebetween;

means for curing (100,

     120) the adhesive material to secure the faceplate to the screen; and

control apparatus for the positioning tool and a detection means for determining when the adhesive material has reached predefined points proximate the outer edges of the opposed surfaces, said control apparatus being connected to respond to signals from the detection means to fix the relative positions of the opposed surfaces.

2. Apparatus according to claim 1, including means for measuring faceplate dimensions for each faceplate and for calculating from said dimensions an optimum volume of adhesive material to be dispensed onto said at least one surface for forming said adhesive layer, wherein said means for dispensing has control means adapted to control dispensing of said calculated optimum volume of adhesive.

3. Apparatus according to claim 1, including means for measuring faceplate dimensions for each faceplate and for calculating from said dimensions an optimum volume of adhesive material to be dispensed onto said at least one surface for forming said adhesive layer, wherein said means for dispensing has control means adapted to control dispensing of said calculated optimum volume of adhesive.