Detection system using photo-sensors

1. Processing unit for drowsiness detection with a processor, a data interface and memory, the memory storing one or more routines executable by the processor,

wherein the processing unit is able to receive light intensity information from a plurality of photo-sensors via the data interface, the light intensity information comprising each photo-sensor's light intensity and the light intensity having more than two levels, and

wherein the one or more routines being adapted to:

determine the change in the light intensity information of the plurality of photo-sensors by directly comparing the light intensity information;

determine movements of the plurality of photo-sensors relative to at least one light source based on the change of light intensity information received from the plurality of photo-sensors with respect to time, comprising:

determine a position of the plurality of photo-sensors relative to the at least one light source based on light intensity information; and

determine the movements based on the change in position.

2. Drowsiness detection system comprising determining a movement of a control device, the system comprising:

a plurality of photo-sensors,

a light source for providing light to the plurality of photo-sensors

a processing unit, and

an interface,

wherein the plurality of photo-sensors is configured to move with the control device and is able to transmit light intensity information to the processing unit and the processing unit is able to receive the light intensity information from the photo-sensors, the light intensity information comprising each photo-sensor's light intensity and the light intensity having more than two levels,

wherein the processing unit is able to provide information to a user via the interface, and

wherein the processing unit is designed to determine the movement of the control device based on the change in the light intensity information submitted by the photo-sensors, comprising:

determine a position of the plurality of photo-sensors relative to the light source based on light intensity information; and

determine the movement based on the change in position.

3. System of claim 2 , wherein the plurality of photo-sensors and the processing unit are combined in a sensor element comprising attaching means for attaching the sensor element on the control device.

4. System of claim 3 , wherein the light source provides patterned light.

5. System of claim 4 , wherein the light source provides infra-red light.

6. System of claim 2 , wherein the system comprises 4-12, preferably 6-10 and more preferably 8 photo-sensors.

7. Method for detecting drowsiness of a driver of a vehicle, with the following steps:

receiving light intensity information from a plurality of photo-sensors, the light intensity information comprising each photo-sensor's light intensity and the light intensity having more than two levels,

determining movements based on the change of the light intensity information, comprising determining a position of the plurality of photo-sensors relative to a light source based on the light intensity information, wherein the movements are determined based on the change in position, and

analyzing the movements for drowsiness indicating patterns.

8. Method of claim 7 , further comprising the step of:

determine the change in the light intensity information of the plurality of photo-sensors by directly comparing the light intensity information,

wherein the movements are determined based on this comparison of light intensity information.

9. Computer program comprising program code means for causing a computer to carry out the steps of the method as claimed in claim 7 when said computer program is carried out on a computer.