THREE-DIMENSIONAL IMAGE SENSING DEVICE AND METHOD OF SENSING THREE-DIMENSIONAL IMAGES

• US 20140192160A1
• Filed: 01/06/2014
• Published: 07/10/2014
• Est. Priority Date: 01/07/2013
• Status: Active Grant

• Current Assignee: Eminence Electronic Technology Pvt. Ltd.
• Original Assignee: Eminence Electronic Technology Pvt. Ltd.
• Inventors: CHANG, TOM, Wu, Kao-Pin, Hung, Shang-Ming, Chuang, Cheng-Ta, Fang, Chih-Jen, Tsai, Kun-Huang, Kuo-Tsai, Tseng
• Granted Patent: US 9,667,883 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 40/28 Recognition of hand or arm movements, e.g. recognition of deaf sign language static hand signs G06V40/113
• CPC Class Codes: H04N 23/745 Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination

Abstract

A three-dimensional image sensing device includes a light source, a sensing module, and a signal processing module. The sensing module includes a pixel array, a control unit, and a light source driver. The light source generates flashing light with a K multiple of a frequency of flicker noise or a predetermined frequency. The pixel array samples the flashing light to generate a sampling result. The control unit executes an image processing on the sampling result to generate a spectrum. The light source driver drives the light source according to the K multiple of the frequency or the predetermined frequency. The signal processing module generates the K multiple of the frequency according to the spectrum, or outputs the predetermined frequency to the light source driver, and generates depth information according to a plurality of first images/a plurality of second images during turning-on/turning-off of the light source included in the sampling result.

Claims

1. A three-dimensional image sensing device, comprising:

a light source for generating flashing light with a K multiple of a frequency of flicker noise or a predetermined frequency, wherein K is a positive real number, and the flicker noise is generated by an alternating current source;

a sensing module, comprising;

a pixel array for sampling the flashing light to generate a sampling result, wherein the sampling result comprises a plurality of first images during turning-on of the light source and a plurality of second images during turning-off of the light source;

a control unit for executing an image processing on the sampling result to generate a spectrum corresponding to the sampling result; and

a light source driver for driving the light source according to the K multiple of the frequency or the predetermined frequency; and

a signal processing module coupled to the sensing module for generating the K multiple of the frequency according to the spectrum, and generating depth information according to the plurality of first images and the plurality of second images, wherein when the K multiple of the frequency is within a predetermined frequency range, the signal processing module outputs the K multiple of the frequency to the light source driver, or when the K multiple of the frequency is outside the predetermined frequency range, the signal processing module outputs the predetermined frequency to the light source driver.

2. The three-dimensional image sensing device of claim 1, wherein the light source is an infrared ray light source or an infrared ray laser light source.

3. The three-dimensional image sensing device of claim 1, wherein the control unit comprises:

an analog-to-digital converter for generating a digital signal according to the sampling result; and

a discrete Fourier transform processor for generating the spectrum corresponding to the sampling result according to the digital signal.

4. The three-dimensional image sensing device of claim 1, wherein the signal processing module comprises:

a flicker noise identifier for determining the flicker noise corresponding to two multiple of an alternating current frequency according to the spectrum, and generating a control signal corresponding to the K multiple of the frequency according to the flicker noise; and

a frequency generator coupled to the flicker noise identifier for generating the K multiple of the frequency according to the control signal.

5. The three-dimensional image sensing device of claim 4, wherein the frequency generator is a delay time oscillator, a resistor-capacitor oscillator, a phase locked loop, a crystal oscillator, a resonator, or a frequency divider.

6. The three-dimensional image sensing device of claim 1, wherein exposure time of the pixel array during turning on of the light source is equal to exposure time of the pixel array during turning off of the light source.

7. The three-dimensional image sensing device of claim 1, wherein the signal processing module is further used for determining a gesture of a user according to a first image of the plurality of first images and a second image of the plurality of second images corresponding to the first image.

8. The three-dimensional image sensing device of claim 1, wherein the sensing module further comprises:

an infrared ray filter for attenuating light except infrared ray.

9. The three-dimensional image sensing device of claim 1, wherein the spectrum corresponds to the plurality of second images of the sampling result during turning-off of the light source.

10. The three-dimensional image sensing device of claim 1, wherein K is N or

11. A method of sensing three-dimensional images, wherein a three-dimensional image sensing device applied to the method comprises a light source, a sensing module, and a signal processing module, the method comprising:

the sensing module driving the light source to generate flashing light with a K multiple of a frequency of flicker noise or a predetermined frequency according to the K multiple of the frequency or the predetermined frequency, wherein K is a positive real number, and the flicker noise is generated by an alternating current source;

the sensing module sampling the flashing light to generate a sampling result, wherein the sampling result comprises a plurality of first images during turning-on of the light source and a plurality of second images during turning-off of the light source;

the sensing module executing an image processing on the sampling result to generate a spectrum corresponding to the sampling result;

the signal processing module directly outputting the predetermined frequency, or generating and outputting the K multiple of the frequency to the sensing module according to the spectrum; and

the signal processing module generating depth information according to the plurality of first images and the plurality of second images.

12. The method of claim 11, wherein the sensing module executing the image processing on the sampling result to generate the spectrum corresponding to the sampling result comprises:

generating a digital signal according to the sampling result; and

generating the spectrum corresponding to the sampling result according to the digital signal.

13. The method of claim 11, wherein the signal processing module generating and outputting the K multiple of the frequency to the sensing module according to the spectrum comprises:

determining the flicker noise corresponding to two multiple of an alternating current frequency according to the spectrum;

generating a control signal corresponding to the K multiple of the frequency according to the flicker noise; and

generating and outputting the K multiple of the frequency to the sensing module according to the control signal.

14. The method of claim 11, wherein exposure time of the pixel array during turning on of the light source is equal to exposure time of the pixel array during turning off of the light source.

15. The method of claim 11, wherein when the K multiple of the frequency is within a predetermined frequency range, the signal processing module outputs the K multiple of the frequency to the light source driver, or when the K multiple of the frequency is outside the predetermined frequency range, the signal processing module outputs the predetermined frequency to the light source driver.

16. The method of claim 11, wherein K is N or