Shielded cable

• US 20040040736A1
• Filed: 08/25/2003
• Published: 03/04/2004
• Est. Priority Date: 08/27/2002
• Status: Abandoned Application

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Nishimura, Shinichi
• Application Number:
  US10/646,887
• Publication Number:
  US 20040040736A1
• Time in Patent Office: Days
• US Class Current: 174/113R
• CPC Class Codes: H01B 11/02 Cables with twisted pairs or quads
• CPC Class Codes: H01B 11/10 Screens specially adapted for reducing interference from external sources

Abstract

In placement of a plurality of signal wires in a shielded cable, a plurality of signal wires for transmitting digital signals of a relatively high frequency are placed adjacent to an outer shield with which the shielded cable is covered, and also adjacent one to another. The degree of capacitive coupling maximized with respect to high-frequency signal wires is thereby maintained with stability, thus enabling impedance control. Also, a skew at the connection between the shielded cable and a connector can be reduced. Thus, a shielded cable is provided in which impedance control and skew control are easily and stably performed without using cost-increasing means such as addition of ground and power supply wires to improve signal quality.

Claims

1. A shielded cable comprising:

first signal wires for transmitting digital signals of a relatively high frequency;

second signal wires for transmitting digital signals of a relatively low frequency; and

a conductor with which said first and second signal wires bundled in a state of being electrically insulated from each other are collectively covered,

wherein said first signal wires are placed adjacent to said conductor and adjacent one to another.

2. The shielded cable according to claim 1, wherein said first signal wires are twisted pairs.

3. The shielded cable according to claim 1, wherein a clock signal of 10 MHz or higher and a plurality of data signals synchronized with the clock signals are transmitted through said first signal wires.

4. The shielded cable according to claim 1, further comprising connectors for connection at its opposite ends, each of said connectors having connector pins being connected to said first and second signal wires, said first signal wires being connected to particular ones of the connector pins which are adjacent one to another.