Browse Prior Art Database

Pinned Optical Connector System

IP.com Disclosure Number: IPCOM000040421D
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Curtis, SA: AUTHOR

Abstract

The trend in personal computer systems toward smaller and lighter machines has led to units which are so small and light that they are considered truly portable. An example of such a machine is the IBM PC Convertible. Additional features, such as a printer or enhanced graphics card, are contained in modules that are added to the system by plugging onto the back of the system. Control of the added features is maintained through an extension of the system's data, address, and control bus that passes out through the back of the main system unit's housing. A 62-position edge card connector is used for this bus extension. This connector depends upon physical pressure between fingers on the card and the tabs in the connector housing to make electrical connection.

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Pinned Optical Connector System

The trend in personal computer systems toward smaller and lighter machines has led to units which are so small and light that they are considered truly portable. An example of such a machine is the IBM PC Convertible. Additional features, such as a printer or enhanced graphics card, are contained in modules that are added to the system by plugging onto the back of the system. Control of the added features is maintained through an extension of the system's data, address, and control bus that passes out through the back of the main system unit's housing. A 62-position edge card connector is used for this bus extension. This connector depends upon physical pressure between fingers on the card and the tabs in the connector housing to make electrical connection. Besides being used to transmit logical data between the host system and features, the connector also carries power supply voltages and ground to the features. With the system being portable, these feature modules are typically connected and disconnected frequently, attached as they are needed and then taken off to keep the system as portable as possible. A problem arises with the reliability of this type of connector system. Multiple insertions and extractions of fingers in and out of connector tabs causes wear of the plating metals (typically gold) on the contacts. Any foreign material which might appear on the contacts while the connector is unmated could prevent subsequent connection from being made. The problem should get worse as systems that use larger word sizes (such as 32 bits) are implemented. An additional problem relates to the human factors aspect of a user plugging and unplugging feature modules to and from the system unit. Connectors are specified as requiring a certain amount of force per contact to assure reliable connection. This is typically on the order of 2 ounces per contact. Therefore, a 62-pin connector need...