OPTICAL SENSOR, RAIN SENSOR AND VEHICLE

• US 20190291697A1
• Filed: 07/13/2018
• Published: 09/26/2019
• Est. Priority Date: 03/23/2018
• Status: Active Grant

• Current Assignee: Accendo Motion Research Co., Ltd., Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: PARK, Jong Min, KONG, Nak Kyoung, CHANG, Seung Hyeok, LEE, Ki Hong, YOO, Nam Joon, HONG, Yong Pyo
• Granted Patent: US 10,800,383 B2
• Time in Patent Office: Days
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
• CPC Class Codes: B60S 1/0833 Optical rain sensor
• CPC Class Codes: B60S 1/0866 including a temperature sensor heating devices for windshield B60H
• CPC Class Codes: B60S 1/087 including an ambient light sensor control of vehicle lights B60Q
• CPC Class Codes: G01K 7/25 for modifying the output characteristic, e.g. linearising
• CPC Class Codes: H01L 31/101 Devices sensitive to infrared, visible or ultraviolet radiation
• CPC Class Codes: H04B 10/502 LED transmitters
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/18 using temperature feedback

Abstract

The present disclosure provides an optical sensor having constant sensitivity regardless of changes in temperature. The optical sensor may include a light emitting device configured to emit light; a light receiving device configured to receive the light emitted from the light emitting device, and to output current based on an intensity of the light; a temperature sensor coupled with the light emitting device, and having electrical resistance varying with temperature; and a microcontroller including a first channel for supplying first current directly to the light emitting device, a second channel for supplying second current to the light emitting device via the temperature sensor, and a third channel for receiving the current output from the light receiving device.

Claims

1. An optical sensor comprising:

a light emitting device configured to emit light;

a light receiving device configured to;

receive the light emitted from the light emitting device; and

output current based on an intensity of the light;

a temperature sensor coupled with the light emitting device, wherein the temperature sensor has electrical resistance varying with temperature; and

a microcontroller comprising;

a first channel configured to supply first current directly to the light emitting device;

a second channel configured to supply second current to the light emitting device via the temperature sensor; and

a third channel configured to receive the current outputted from the light receiving device.

2. The optical sensor of claim 1, wherein the microcontroller is configured to supply the first current and the second current to the light emitting device by alternating the first channel and the second channel.

3. The optical sensor of claim 1, wherein the microcontroller is configured to determine a setting value of the first current that is supplied to the light emitting device through the first channel based on the current outputted from the light receiving device when the microcontroller supplies the second current to the light emitting device through the second channel.

4. The optical sensor of claim 3, wherein the microcontroller is configured to:

supply the first current having the setting value to the light emitting device through the first channel; and

measure the current outputted from the light receiving device.

5. The optical sensor of claim 1, wherein the microcontroller is configured to decrease the setting value of the first current that is supplied directly to the light emitting device through the first channel when the current outputted from the light receiving device increases and the microcontroller supplies the second current to the light emitting device through the second channel.

6. The optical sensor of claim 1, wherein the microcontroller is configured to increase the setting value of the first current that is supplied directly to the light emitting device through the first channel when the current outputted from the light receiving device decreases and the microcontroller supplies the second current to the light emitting device through the second channel.

7. A rain sensor comprising:

first light emitting device configured to emit first light;

second light emitting device configured to emit second light;

a light receiving device configured to;

receive the first light or the second light emitted from at least one of the first lighting emitting device or the second light emitting device; and

output current based on an intensity of the first light or the second light;

a temperature sensor coupled with the second light emitting device, wherein the temperature sensor has electrical resistance varying with temperature; and

a microcontroller comprising;

a first channel configured to supply first current directly to the first light emitting device;

a second channel configured to supply second current to the second light emitting device via the temperature sensor; and

a third channel configured to receive the current outputted from the light receiving device.

8. The rain sensor of claim 7, wherein the microcontroller is configured to determine a setting value of the first current that is supplied to the first light emitting device based on the current outputted from the light receiving device when the microcontroller supplies the second current to the second light emitting device.

9. The rain sensor of claim 8, wherein the microcontroller is configured to:

supply the first current having the setting value to the first light emitting device; and

determine whether it rains based on the current outputted from the light receiving device.

10. The rain sensor of claim 7, wherein the microcontroller is configured to:

supply the first current to the first light emitting device through the first channel; and

when the current outputted from the light receiving device is greater than a predetermined upper limit value, decease a setting value of the first current that is supplied to the first light emitting device through the first channel.

11. The rain sensor of claim 7, wherein the microcontroller is configured to:

supply the first current to the first light emitting device through the first channel; and

when the current outputted from the light receiving device is less than a predetermined lower limit value, increase the setting value of the first current that is supplied to the first light emitting device through the first channel.

12. The rain sensor of claim 7, wherein the microcontroller is configured to:

supply the second current to the second light emitting device through the second channel; and

when the current outputted from the light receiving device increases and the microcontroller supplies the second current to the second light emitting device through the second channel, decrease the setting value of the first current that is supplied to the first light emitting device through the first channel.

13. The rain sensor of claim 7, wherein the microcontroller is configured to:

supply the second current to the second light emitting device through the second channel; and

when the current outputted from the light receiving device increases and the microcontroller supplies the second current to the second light emitting device through the second channel, decrease the setting value of the first current that is supplied to the first light emitting device through the first channel.

14. A vehicle comprising:

a front window;

a rain sensor configured to detect raindrops on the front window;

a wiper configured to remove the raindrops on the front window; and

a controller configured to operate the wiper based on a signal from the rain sensor,

wherein the rain sensor comprises;

first light emitting device configured to emit first light;

second light emitting device configured to emit second light;

a light receiving device configured to;

receive the first light or the second light emitted from at least one of the first light emitting device or the second light emitting device; and

output current based on an intensity of the first light or the second light;

a temperature sensor coupled with the second light emitting device, wherein the temperature sensor has electrical resistance varying with temperature; and

a microcontroller comprising;

a first channel configured to supply first current directly o the first light emitting device;

a second channel configured to supply second current to the second light emitting device via the temperature sensor; and

a third channel configured to receive the current outputted from the light receiving device.

15. The vehicle of claim 14, wherein the microcontroller is configured to determine a setting value of the first current that is supplied to the first light emitting device through the first channel based on the current outputted from the light receiving device when the controller supplies the second current to the second light emitting device.

16. The vehicle of claim 15, wherein the microcontroller configured to:

supply the first current having a setting value to the first light emitting device; and

determine whether it rains based on the current outputted from the light receiving device.

17. The vehicle of claim 14, wherein the microcontroller configured to:

supply the first current to the first light emitting device through the first channel; and

when the current outputted from the light receiving device is greater than a predetermined upper limit value, decrease the setting value of the first current that is supplied to the first light emitting device through the first channel.

18. The vehicle of claim 14, wherein the microcontroller is configured to:

supply the first current to the first light emitting device through the first channel; and

when the current outputted from the light receiving device is less than a predetermined lower limit value, increase the setting value of the first current that is supplied to the first light emitting device through the first channel.

19. The vehicle of claim 14, wherein the microcontroller is configured to:

supply the second current to the second light emitting device through the second channel; and

when the current outputted from the light receiving device increases and the microcontroller supplies the second current to the second light emitting device through the second channel, decrease the setting value of the first current that is supplied to the first light emitting device through the first channel.

20. The vehicle of claim 14, wherein the microcontroller is configured to:

supply the second current to the second light emitting device through the second channel; and

when the current outputted from the light receiving device increases and the microcontroller supplies the first current to the first light emitting device through the first channel, decrease the setting value of the first current that is supplied to the first light emitting device through the first channel.