Silicone rubber surfaces for biometric print TIR prisms

• US 7,319,565 B2
• Filed: 02/17/2006
• Issued: 01/15/2008
• Est. Priority Date: 04/26/2001
• Status: Expired due to Term

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: Bardons, Charles P., Arnold, Joe F.
• Primary Examiner(s): Shafer; Ricky D.
• Application Number:
  US11/356,036
• Publication Number:
  US 20060139778A1
• Time in Patent Office: 697 Days
• Field of Search: 359/831, 359/833, 359/837, 356/71, 356/446, 382/115, 382/124, 382/125, 382/127, 428/425.5, 428/447
• US Class Current: 359/831
• CPC Class Codes: B29C 37/006 Degassing moulding material or draining off gas during moulding venting means in moulds B29C33/10
• CPC Class Codes: B29C 37/0078 Measures or configurations for obtaining anchoring effects in the contact areas between layers surface shaping B29C59/00; B29C66/02 takes precedence
• CPC Class Codes: B29C 39/02 for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29C 39/10 incorporating preformed parts or layers, e.g. casting around inserts or for coating articles coating a surface by casting in general B05D1/30, B29C39/126 takes precedence
• CPC Class Codes: B29K 2083/005 LSR, i.e. liquid silicone rubbers, or derivatives thereof
• CPC Class Codes: B32B 17/063 of rubber
• CPC Class Codes: B32B 17/10 of synthetic resin
• CPC Class Codes: B32B 2038/0076 Curing, vulcanising, cross-linking
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2319/00 Synthetic rubber natural rubber B32B2317/22
• CPC Class Codes: B32B 2323/04 Polyethylene
• CPC Class Codes: B32B 2327/18 PTFE, i.e. polytetrafluoroethylene
• CPC Class Codes: B32B 2369/00 Polycarbonates
• CPC Class Codes: B32B 25/04 comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/043; next to a bituminous or tarry layer B32B11/044; next to a water setting substance layer B32B13/042; next to a metal layer B32B15/06; next to a glass layer B32B17/063; next to a layer formed of natural mineral fibres or particles B32B19/043; next to a wood layer B32B21/045; next to a cellulosic plastic layer B32B23/046
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 25/20 comprising silicone rubber
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/322 comprising halogenated polyolefins, e.g. PTFE
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: G02B 1/10 : Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 5/04 : Prisms
• CPC Class Codes: G02B 7/18 : for prisms; for mirrors
• CPC Class Codes: G06V 40/1324 : by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: Y10T 428/31598 : Next to silicon-containing [silicone, cement, etc.] layer

Abstract

Molded silicone rubber sheets with optical quality surfaces and methods for making the same. The silicone rubber sheets are made by molding liquid silicone rubber in a mold. In embodiments, the mold forms parallel optical quality flat surfaces. In one embodiment, a stiffening plastic is molded in the middle of the silicone rubber sheet between the parallel optical quality flat surfaces. In another embodiment, the mold forms one optical quality flat surface while the surface parallel to the optical quality flat surface is bonded to a prism.

Claims

1. A total internal reflective (TIR) platen for a biometric imaging device, comprising:

a first layer of silicone rubber compound having an optical quality surface;

a second layer of silicone rubber compound having an optical quality surface;

a layer of stiff plastic embedded between the first layer of silicone rubber and the second layer of silicone rubber,

wherein the optical quality surface of the first layer of silicone rubber compound provides for a total internal reflective platen surface and the optical quality surface of the second layer of silicone rubber compound provides for making optical contact with a prism.

2. The TIR platen of claim 1, wherein the optical quality surface of the second layer of silicone rubber compound is attached to the prism.

3. The TIR platen of claim 1, wherein the optical quality surface of the second layer of silicone rubber compound is integrally molded to the prism.

4. The TIR platen of claim 1, further comprising:

a first binder layer positioned between the first layer of silicone rubber and the layer of stiff plastic, wherein the first layer of silicone rubber is bound to the layer of stiff plastic; and

a second binder layer positioned between the second layer of silicone rubber and the layer of stiff plastic, wherein the second layer of silicone rubber is bound to the layer of stiff plastic.

5. The TIR platen of claim 1, wherein the layer of stiff plastic comprises at least one of:

polycarbonate, acrylic, CR39, or styrene.