Three dimensional image projector stabilization circuit

• US 9,004,700 B2
• Filed: 01/25/2012
• Issued: 04/14/2015
• Est. Priority Date: 01/25/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DeCusatis, Casimer M.
• Primary Examiner(s): CHOWDHURY, SULTAN U.
• Application Number:
  US13/357,725
• Publication Number:
  US 20130188148A1
• Time in Patent Office: 1,175 Days
• Field of Search: 353/7, 353/8, 353/20, 353/30, 353/31, 353/122, 353/85, 353/94, 353/9, 372/29.011, 372/29.015, 372/30, 315/368.15, 315/368.18, 315/370, 315/371, 348744-747, 348/769, 348/E9.026
• US Class Current: 353/99
• CPC Class Codes: G03B 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197
• CPC Class Codes: G03B 35/16 by sequential viewing
• CPC Class Codes: G03B 35/26 using polarised or coloured light separating different viewpoint images
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

A projector system that includes a first input device, a second input device, a control device, a sensor and a phase locked loop (PLL). A phase reference signal is created based on a signal rate of the first input device. A phase feedback signal is created based on the rotational speed of the second input device as it is measured by the sensor. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

Claims

1. A projector system for a portable electronic device, the projector system comprising:

a first input device;

a second input device;

a control device;

a sensor; and

a phase locked loop (PLL), the projector system configured for;

creating a phase reference signal based on a signal rate of the first input device;

creating a phase feedback signal based on the rotational speed of the second input device as measured by the sensor;

comparing, by the PLL, the phase reference signal and the phase feedback signal to determine whether the light device and the second input device are synchronized;

sending, by the PLL, a signal to the control device, the sending responsive to determining that the first input device and the second input device are not synchronized; and

changing, by the control device, the rotational speed of the second input device resposive to the signal.

2. The projector system of claim 1, wherein the projector system is further configured for applying a programmable delay to the phase feedback signal prior to the comparing by the PLL.

3. The projector system of claim 1, wherein the projector system is further configured applying at least one of a signal conditioner and a signal amplifier the phase feedback signal prior to the comparing by the PLL.

4. The projector system of claim 1, wherein the projector system is further configured for modifying the phase reference signal prior to the comparing by the PLL.

5. The projector system of claim 1, wherein the first input device is an imaging device.

6. The projector system of claim 1, wherein the first input device is a light source.

7. The projector system of claim 1, wherein the second input device is a rotating polarizing beam splitter (PBS).

8. The projector system of claim 1, wherein the second input device is a digital mirror device (DMD) comprising rotating mirrors.

9. The projector system of claim 1, wherein the sensor is a tachometer.

10. A system comprising:

a first input device;

a second input device;

a control device in communication with a digital mirror device (DMD) device, the control device configured for controlling a rotational speed of the DMD device;

a sensor in communication with the DMD device, the sensor configured for determining the rotational speed of mirrors within the DMD device and for outputting a phase feedback signal based on the rotational speed of the mirrors;

a quiescence delay device electrically coupled to receive the phase feedback signal; and

a phase locked loop configured for receiving a phase reference signal from a light source, for receiving the phase feedback signal from the quiescence delay device, for comparing the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized, and for sending a first signal to the control device to change the rotational speed of the mirrors responsive to determining that the light source and the DMD device are not synchronized.

11. The system of claim 10, wherein the light source and the DMD device are located on a three dimensional (3D) projector system for a portable electronic device.

12. The system of claim 10, wherein the phase lock loop is configured for sending a second signal to the quiescence delay device in response to determining that the light source and the DMD device are not synchronized.

13. The system of claim 10, wherein the light source includes a first light source and a second light source, the first light source, the second light source and the DMD device being located on a 3D projector system for a portable electronic device.

14. A projector system for a portable electronic device, the projector system comprising:

a first input device;

a second input device;

a polarizing beam splitter (PBS), the PBS configured to rotate about a first axis;

a tachometer operably coupled to measure a rotational speed of the PBS;

a control device configured for controlling the rotational speed of the PBS;

a phase locked loop (PLL) electrically coupled to the tachometer; and

a quiescence delay device electrically coupled between the tachometer and the PLL, the quiescence delay device configured to delay the transmission of a phase feedback signal;

wherein the phase locked loop is configured for receiving a phase reference signal from the first input device, for receiving the phase feedback signal from the quiescence delay device, for comparing the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized, and for sending a first signal to the control device to change the rotational speed of the PBS in response to determining that the first input device and second input device are not synchronized.

15. The projector system of claim 14 wherein the PLL is further configured to generate a second signal in response to determining that the first input device and the PBS are not synchronized, and the quiescence delay device changes a delay period of the phase feedback signal in response to receiving the second signal.

16. The projector system of claim 15 wherein the light source comprises:

a first light source emitting a first light along an optical axis, the optical axis being substantially perpendicular to the first axis;

a second light source emitting a second light along the optical axis in a direction substantially opposite the first light source; and

the PBS being disposed between the first light source and the second light source.

17. The projector system of claim 16 wherein the image generator is arranged to receive the first light and the second light reflected with the PBS and configured to reflect the first light and the second light therefrom.