Optical distance detection system
View Patent ↗There is provided an optical distance detection system which includes a light source and a detection device. The light source is configured to illuminate a surface of an object. The detection device is configured to receive a reflected light from the surface of the object and to output a distance of the object according to the reflected light. The detection device includes a sensing module and a calculation module. The sensing module is configured to receive the reflected light to accordingly generate an image. The calculation module is for outputting the distance according to a light spot position and a light spot size of the reflected light forming on the image.
1. An optical distance detection system, comprising:
a light source configured to illuminate a surface of an object; and
a detection device configured to receive reflected light from the surface of the object and output a distance of the object according to the reflected light, the detection device further comprising:
a sensing module configured to receive the reflected light to accordingly generate an image; and
a calculation module configured to
compensate a light spot position according to a light spot size of a light spot formed by the reflected light on the image,
determine a compensation direction according to symmetry of a one-dimensional energy curve of the light spot formed by the reflected light, and
calculate and output the distance of the object according to the compensated light spot position.
2. The optical distance detection system as claimed in claim 1 , wherein the sensing module further comprises:
a light sensing unit configured to receive the reflected light and generate an electric signal; and
an image processing unit configured to receive the electric signal and generate the image.
3. The optical distance detection system as claimed in claim 1 , wherein the calculation module further comprises:
a calculation unit configured to receive the image, compensate the light spot position according to the light spot size of the light spot, and calculate the distance according to the compensated light spot position; and
an output unit configured to receive the distance obtained by the calculation unit and output the distance.
4. The optical distance detection system as claimed in claim 3 , wherein
the calculation module further comprises a memory unit configured to store a predetermined light spot size; and
the calculating unit is configured to compare the light spot size and the predetermined light spot size after receiving the image, and compensate the light spot position according to a comparison result of the light spot size and the predetermined light spot size.
5. The optical distance detection system as claimed in claim 4 , wherein
the calculation unit is configured to calculate the distance according to the light spot position, which is uncompensated, when the light spot size is equal to the predetermined light spot size; and
the calculation unit is configured to
compensate the light spot position according to a size difference between the light spot size and the predetermined light spot size when the light spot size is smaller than the predetermined light spot size, and
calculate the distance according to the compensated light spot position.
6. The optical distance detection system as claimed in claim 5 , wherein
the light spot position is a gravity center of the light spot; and
the calculation unit is configured to compensate the gravity center when compensating the light spot position, and calculate the distance according to the compensated gravity center.
7. The optical distance detection system as claimed in claim 6 , wherein the gravity center is an energy center within a full width at half maximum of the one-dimensional energy curve or a maximum position of the one-dimensional energy curve.
8. The optical distance detection system as claimed in claim 7 , wherein the calculation unit is further configured to determine the compensation direction of the gravity center according to the symmetry of the one-dimensional energy curve.
9. The optical distance detection system as claimed in claim 8 , wherein
the light spot is divided into a left part and a right part by the gravity center of the one-dimensional energy curve,
one of the left part and the right part is smaller than the other, and
the compensation direction is oriented toward the smaller one of the left part and the right part.
10. The optical distance detection system as claimed in claim 5 , wherein
the size difference is a light spot ratio obtained by dividing the light spot size to the predetermined light spot size; and
the memory unit is configured to store a lookup table of the light spot ratio and a compensation amount of light spot position.
11. An optical distance detection system, comprising:
a light source configured to illuminate a surface of an object;
a detection lens; and
a detection device configured to
detect a light spot formed by reflected light on the detection device, the reflected light reflected from the surface of the object, penetrating the detection lens and incident on the detection device,
compensate a light spot position according to a light spot size of the light spot, and
determine a compensation direction of the light spot position according to symmetry of a one-dimensional energy curve of the light spot.
12. The optical distance detection system as claimed in claim 11 , wherein
the light spot is divided into a left part and a right part by a gravity center of the one-dimensional energy curve,
one of the left part and the right part is smaller than the other, and
the compensation direction is oriented toward the smaller one of the left part and the right part.
13. The optical distance detection system as claimed in claim 11 , wherein the detection device further comprises a memory unit configured to store a predetermined light spot size and a lookup table of a light spot ratio and a compensation amount of light spot position, wherein the light spot ratio is obtained by dividing the light spot size to the predetermined light spot size.
14. The optical distance detection system as claimed in claim 13 , wherein the detection device is configured to compensate the light spot position according to the light spot size and the lookup table.
15. The optical distance detection system as claimed in claim 14 , wherein the detection device is configured to
calculate a distance according to the light spot position, which is uncompensated, when the light spot ratio is equal to 1; and
calculate the distance according to the compensated light spot position when the light spot ratio is less than 1.
16. The optical distance detection system as claimed in claim 15 , wherein the detection device is further configured to output the distance to a host.
17. The optical distance detection system as claimed in claim 11 , wherein the light spot position is an energy center within a full width at half maximum of the one-dimensional energy curve or a maximum position of the one-dimensional energy curve.
18. The optical distance detection system as claimed in claim 11 , wherein
the detection device further comprises a sensing module and a calculation module;
the sensing module is configured to acquire an image containing the light spot;
the calculation module is configured to calculate the light spot size and the one-dimensional energy curve of the light spot according to the image, to compensate the light spot position according to the light spot size, and to determine the compensation direction according to the symmetry of the one-dimensional energy curve.
19. The optical distance detection system as claimed in claim 18 , wherein
the sensing module further comprises a light sensing unit and an image processing unit;
the light sensing unit is configured to detect the reflected light to generate an electric signal, and
the image processing unit is configured to generate the image containing the light spot according to the electric signal.
20. An optical distance detection system, comprising:
a light source configured to illuminate a surface of an object;
a detection lens; and
a detection device configured to
detect a light spot formed by reflected light on the detection device, the reflected light reflected from the surface of the object, penetrating the detection lens and incident on the detection device, and
determine a compensation direction of a light spot position of the light spot according to symmetry of a one-dimensional energy curve of the light spot.