Automatic position control system for x-ray machines

• US 5,483,072 A
• Filed: 08/04/1994
• Issued: 01/09/1996
• Est. Priority Date: 08/04/1994
• Status: Expired due to Fees

• Current Assignee: Hologic Incorporated, Bennett X-Ray Corp. (Thermo Fisher Scientific Incorporated)
• Original Assignee: Bennett X-Ray Technologies
• Inventors: Coe, Robert P.
• Primary Examiner(s): Willis, Davis L.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US08/286,484
• Time in Patent Office: 523 Days
• Field of Search: 250/370.1, 250/374, 250/385.1, 250/390.12
• US Class Current: 250/385.1
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: G21K 5/10 with provision for relative movement of beam source and object to be irradiated

Abstract

An x-ray machine, such as a mammography machine, comprises a source of a narrow beam of radiation which scans across an object, e.g., a breast, to be imaged. A sensor for the narrow beam moves in the same direction as the narrow beam. The sensor generates an output signal which indicates the position of the beam relative to a specific location on the sensor. A control circuit receives the signal from the sensor and outputs a control signal to regulate the position of the beam relative to the sensor.

Claims

1. An x-ray sensor comprising

an ionization chamber

a first element separated by a gas from a second element mounted inside said ionization chamber,

said first element comprising

a plurality of sensing strips separated by resistors, and

a first and a second terminal each terminated by a

terminating resistor, wherein an output voltage obtained between said first and second terminals represents the position of an incident narrow x-ray beam.

2. The x-ray sensor of claim 1, wherein said plurality of sensing strips are arranged in a row.

3. An x-ray sensor comprising

a plurality of photodiodes connected in series separated by resistors, and

a first and a second terminal each terminated by a

terminating resistor, wherein an output voltage obtained between said first and second terminals represent the position of an incident narrow x-ray beam.

4. The x-ray sensor of claim 3, wherein said plurality of photodiodes are arranged in a row.