Process for the sampling of an electric signal varying over time and apparatus for the implementation and application of this process

• US 4,864,522 A
• Filed: 02/25/1988
• Issued: 09/05/1989
• Est. Priority Date: 02/25/1987
• Status: Expired due to Fees

• Current Assignee: Brown Boveri & CIE AG (ABB Limited)
• Original Assignee: Brown Boveri & CIE AG (ABB Limited)
• Inventors: Heimgartner, Dieter, Schad, Hanspeter, Kaufmann, Meinolph
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Teska, Kevin S.
• Application Number:
  US07/160,249
• Time in Patent Office: 558 Days
• Field of Search: 364/487, 364/550, 364/551.01, 364/557, 364/575, 364/556, 250/327.2 C, 250/327.22, 324/77 B, 324/77 R, 356/73.1, 315/8.51, 341/122, 341/137
• US Class Current: 702/199
• CPC Class Codes: G01M 11/3109 Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
• CPC Class Codes: G01R 13/347 using electro-optic elements

Abstract

In a process for the sampling of an electric signal changing over time, an electron beam (12) is deflected laterally and linearly over time and at the same time modulated in its intensity according to the instantaneous amplitude of the electric signal. The electron beam (12) generates on a fluorescent screen (14) a brightness-modulated bar of light, which is preferably sampled with a sensor (15) arranged ahead of the fluorescent screen (14) in the form of a CCD line camera having a linear array of sensor elements (15a, b, c).

The read-out analog sampled values of the sensor (15) are subsequently digitized and further processed.

The advantage of the process is its high broad-bandedness and resolution and the capability of being able to carry out an averaging without additional expenditure of time.

Claims

1. Process for sampling several electric signals varying over time, comprising the steps of:

generating an electron beam having a controllable intensity;

deflecting said electron beam laterally and linearly over time;

successively modulating the intensity of the electron beam during the deflection by an instanteous amplitude of the electric signals;

successively converting the intensity of the electron beam into samples values by a sensor consisting of a plurality of sensor elements arranged alongside one another;

analogly averaging the samples values directly in each of the sensor elements; and

successively reading out and digitizing the averaged, sample values.

2. Process for sampling several electric signals varying over time comprising the steps of:

generating an electron beam having a controllable intensity;

deflecting said electron beam laterally and linearly over time by a saw tooth voltage, thereby generating a bar of light on a fluorescent screen;

successively modulating the intensity of the electron beam during the deflection by an instanteous amplitude of the electric signals, thereby generating an intensity modulated bar of light;

converting the intensity modulated bar of light into sampled values by a light-sensitive sensor, said light-sensitive sensor comprising a plurality of sensor elements arranged alongside one another and a storage element for each of the sensor elements;

analogly averaging the sampled values in each of the storage elements; and

successively reading out and digitizing the averaged, sampled values.

3. Apparatus for sampling several electric signals varying over time, comprising:

an electron beam tube generating an electron beam having a controllable intensity;

a deflection device for laterally deflecting said electron beam;

a time base controlling the deflection device and generating a saw tooth-shaped voltage for successively deflecting said electron beam laterally and linearly over time;

means for successively modulating the intensity of the electron beam during the deflection by an instanteous amplitude of the electric signals;

a sensor for sampling the intensity of the electron beam, said sensor comprising a plurality of sensor elements arranged alongside one another and a storage element for each sensor element for analog averaging, said sensor being arranged on the electron beam tube such that the deflected electron beam successively sweeps over the sensor elements;

a data processor for processing sampled and averaged values.

4. Apparatus for sampling several electric signals varying over time, comprising:

an electron beam tube generating an electron beam having a controllable intensity;

a deflection device for laterally reflecting said electron beam on a fluorescent screen;

a time base controlling the deflection device and generating a saw tooth-shaped voltage for successively deflecting said electron beam laterally and linearly over time;

means for successively modulating the intensity of the electron beam during the deflection by an instanteous amplitude of the electric signals and for generating an intensity modulated light bar on the fluorescent screen;

a CCD line camera for converting and averaging the intensity modulated light bar into sampled values, said CCD line camera comprising a plurality of sensor elements arranged alongside one another and storage elements, which are assigned to the sensor elements and form a CCD shift register, said sensor being arranged on the electron beam tube such that the deflected electron beam successively sweeps over the sensor elements;

a sensor control acting on the CCD shift register by setting the storage elements to zero before a measurement and reading out the averaged sampled values;

an A/D converter for digitizing the averaged sampled values; and

a data processor for processing said digitized sampled values.

5. Apparatus for signal conditioning or periodically repeating backscattering signals occurring in optical time domain reflectometry measurements on glass fibers, comprising:

an electron beam tube generating a electron beam having a controllable intensity;

a deflection device for laterally deflecting said electron beam on a fluorescent screen;

a time base controlling the deflection device and generating a saw tooth-shaped voltage for successively deflecting said electron beam laterally and linearly over time;

means for successively modulating the intensity of the electron beam during the deflection by an instanteous amplitude of the backscattering signals and for generating an intensity modulated bar of light on the fluorescent screen;

a CCD screen for converting and averaging the intensity modulated bar of light into sampled values, said CCD line camera comprising a plurality of sensor elements arranged alongside one another and storage elements, which are assigned to the sensor elements and form a CCD shift register, said sensor being arranged on the electron beam tube such that the deflected electron beam successively sweeps over the sensor elements;

a sensor control acting on the CCD shift register by setting the storage elements to zero before a measurement and reading out the averaged sampled values;

an A/D converter for digitizing the sampled values; and

a data processor for processing said digitized sampled values.