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US 6,714,283 B2Granted
Sensor and method for range measurements using a TDI device
AssigneeInstitut National D'Optique
InventorsJohn Laurent, Denis Boulanger
Life of this patent
Estimating the term…
Abstract
A sensor and method for taking range measurements of a target object using a TDI device as a detector are provided. The device is positioned to detect reflections of a structured light beam on the target object. To avoid losing the range information in the TDI process, the exposition of the device to the reflection of the light beam is restricted to the first integration period of the acquisition cycle of the TDI device, so that the output of the device provides line by line an image of the light beam on the target object during this first integration period.
Claims15
A sensor for measuring a range to a target object by triangulation using a TDI device, comprising:
- a light source generating a light beam for projection towards the target object and for reflection thereon positioned along a short axis of said TDI device;
- a plurality of photodetector arrays disposed contiguously in a linear sequence and defining the TDI device, said TDI device being positioned to detect the reflection of the light beam on the target object across a plurality of said photodetector arrays, said TDI device being operable over an acquisition cycle composed of a number of integration periods, each photodetector array accumulating electronic charges representative of light incident thereon during each integration period, each of said photodetector arrays transferring all electronic charges therein to a next photodetector array along said linear sequence after each integration period, said TDI device having an output for transmitting all electronic charges from a last photodetector array along said linear sequence after each integration period;
- restricting means for restricting an exposition of the TDI device to the reflection of the light beam on the target object to a single integration period of the acquisition cycle;
- and
- processing means for receiving the electronic charges from the output of the TDI device after each integration period of the acquisition cycle and processing the electronic charges of the acquisition cycle to obtain therefrom the range to the target object.
2 more elements
A sensing apparatus for measuring a range to a target object over a plurality of regions thereof by triangulation using a TDI device, comprising:
- a light source generating a light beam for projection towards an exposition area positioned along a short axis of said TDI;
- positioning means for successively positioning each of the regions of said target object within the exposition area;
- a plurality of photodetector arrays disposed contiguously in a linear sequence and defining the TDI device, said TDI device being positioned to detect the reflection of the light beam on a region of the target object extending in the exposition area across a plurality of said photodetector arrays, said TDI device being operable over a plurality of acquisition cycle each composed of a number of integration periods, each photodetector array accumulating electronic charges representative of light incident thereon during each integration period, each of said photodetector arrays transferring all electronic charges therein to a next photodetector array along said linear sequence after each integration period, said TDI device having an output for transmitting all electronic charges from a last photodetector array along said linear sequence after each integration period;
- restricting means for restricting an exposition of the TDI device to the reflection of the light beam on each region of the target object to a single integration period of each acquisition cycle;
- and
- processing means for receiving the electronic charges from the output of the TDI device after each integration period of each acquisition cycle and processing the electronic charges of each acquisition cycle to obtain therefrom the range to the region of the target object during the selected integration period of said acquisition cycle.
3 more elements
A method for measuring by triangulation a range to a target object extending in an exposition area using a TDI device, comprising the steps of:
- a) generating a light beam, and projecting said light beam towards the exposition area for reflection on the target object said light beam being positioned along a short axis of said TDI;
- b) disposing a plurality of detector arrays, defining said TDI device, contiguously in a linear sequence, said TDI device being positioned to detect the reflection of the light beam on the target object within the exposition area across a plurality of the photodetector arrays, said TDI device having, in operation, an acquisition cycle composed of a number of integration periods, each photodetector array accumulating electronic charges representative of light incident thereon during each integration period, each of said photodetector arrays transferring all electronic charges therein to a next photodetector array along said linear sequence after each integration period, said TDI device having an output for transmitting all electronic charges from a last photodetector array along said linear sequence after each integration period;
- c) restricting an exposition of the TDI device to the reflection of the light beam on the target object to a single integration period of the exposition cycle;
- and
- d) receiving the electronic charges from the output of the TDI device after each integration period of the acquisition cycle and processing the electronic charges of the acquisition cycle to obtain therefrom the range to the target object.
2 more elements
A method for measuring by triangulation a range to a target object over a plurality of regions thereof using a TDI device, comprising the steps of:
- a) generating a light beam and projecting the same towards an exposition area said light beam being positioned along a short axis of said TDI;
- b) successively positioning each of the regions of said target object within the exposition area;
- c) disposing a plurality of detector arrays, defining said TDI device, contiguously in a linear sequence, said TDI device being positioned to detect the reflection of the light beam on the region of the target object within the exposition area across a plurality of the photodetector arrays, said TDI device having, in operation, a plurality of acquisition cycles each composed of a number of integration periods, each photodetector array accumulating electronic charges representative of light incident thereon during each integration period, each of said photodetector arrays transferring all electronic charges therein to a next photodetector array along said linear sequence after each integration period, said TDI device having an output for transmitting all electronic charges from a last photodetector array along said linear sequence after each integration period of each acquisition cycle;
- d) restricting an exposition of the TDI device to the reflection of the light beam on each region of the target object to a single integration period of a corresponding acquisition cycle;
- and
- e) receiving the electronic charges from the output of the TDI device after each integration period of each acquisition cycle and processing the electronic charges each of the acquisition cycle to obtain therefrom the range to the corresponding region of the target object.
3 more elements
Dependencies are inferred from the claim text.