A SYSTEM AND METHOD OF COMPUTING ROTATION ANGLE AND TILT ANGLE BY EMPLOYING AN OPTO-MECHANICAL TECHNIQUE

FIELD OF THE INVENTION

[0001] The present invention relates to the field of computing rotation angle and tilt angle in display devices.

BACKGROUND

[0002] Computing rotation angle and tilt angle is becoming increasingly necessary as display devices, for example but not limited to mobile phones, smart phones and personal digital assistants, support numerous applications that perform one or more actions based on orientation of the display devices. In one example, a gaming application installed on a mobile device employs the rotation angle and tilt angle for varying positions of various gaming elements, of the gaming application, that are displayed on the mobile device.

[0003] One of a conventional technique for calculating the rotation angle and the tilt angle includes employing a joint ball and a socket. Two permanent magnets are arranged in parallel to one another in the joint ball. A display device is arranged in the form of a magneto-optic plate in vicinity of the magnets. The magnets generate a magnetic field, so that the magnetic field intensity changes over the optical plate. When the optical plate is exposed to light, the electromagnetic waves are reflected as a function of the magnetic field, so that an image can be detected in reflected path of rays and the magnetic field in the area of the optical plate can be inferred from this image. As a result of detection of the image, relative position of the ball and socket joint is calculated for obtaining a tilting moment corresponding to the position of the ball and socket joint.

[0004] However, this technique employs various magneto-optic and image processing algorithms for determining the tilt angle. Also, additional devices such as image detection devices and magnets are required, thereby computation becomes expensive. Further the magnetic field may encounter interference thereby leading to erroneous computation of the rotation angle and the tilt angle.

[0005] In the light of the foregoing discussion there is a need for an efficient method and a system for computing the rotation angle and the tilt angle by employing an opto-mechanical technique.

SUMMARY

[0006] Embodiments of the present disclosure described herein provide a system and a method for computing rotation angle and tilt angle by employing an opto-mechanical technique.

[0007] An example of a method of computing a rotation angle, by employing an opto-mechanical technique, on a display device includes determining a state change for a pair of light sensors, of a plurality of light sensors. The state change occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by a metal ball. Further, the method includes determining the rotation angle and the tilt angle, of the metal ball with a base, based on the state change of the pair of light sensors. Moreover, the method includes controlling an entity, on the display device, based on the rotation angle and the tilt angle.

[0008] An example of a system for computing a rotation angle and a tilt angle, by employing an opto-mechanical technique, on a display device includes a communication interface for establishing communication. The system also includes a memory that stores instructions. The system further includes a processor responsive to the instructions to determine a state change for a pair of light sensors, of a plurality of light sensors. The state change occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by a metal ball, to determine the rotation angle and the tilt angle, of the metal ball with a base, based on the state change of the pair of light sensors and to control an entity, on the display device, based on the rotation angle and the tilt angle.

BRIEF DESCRIPTION OF FIGURES

[0009] The accompanying figure, similar reference numerals may refer to identical or functionally similar elements. These reference numerals are used in the detailed description to illustrate various embodiments and to explain various aspects and advantages of the present disclosure.

[0010] FIG. 1 is a flowchart illustrating a method of computing a rotation angle, by employing an opto-mechanical technique, on a display device in accordance with one embodiment;

[0011] FIG. 2 is a block diagram of a display device for computing a rotation angle and a tilt angle, by employing an opto-mechanical technique, on a display device in accordance with one embodiment;

[0012] FIG. 3A-3B is an exemplary illustration of computing a rotation angle and a tilt angle when a metal ball is positioned at centre of a base, in accordance with one embodiment; and

[0013] FIG. 4A-4B is an exemplary illustration of computing a rotation angle and a tilt angle when a metal ball is positioned at left corner of a base, in accordance with one embodiment.

DETAILED DESCRIPTION

[0014] It should be observed the method steps and system components have been represented by conventional symbols in the figure, showing only specific details which are relevant for an understanding of the present disclosure. Further, details may be readily apparent to person ordinarily skilled in the art may not have been disclosed. In the present disclosure, relational terms such as first and second, and the like, may be used to distinguish one entity from another entity, without necessarily implying any actual relationship or order between such entities.

[0015] Embodiments of the present disclosure described herein provide a method and system for computing a rotation angle and a tilt angle for positioning an image on a display device.

[0016] FIG. 1 is a flowchart illustrating a method of computing a rotation angle and a tilt angle, by employing an opto-mechanical technique, on a display device, in accordance with one embodiment. The method starts at step 105.

[0017] At step 110, a state change for a pair of light sensors, of a plurality of light sensors, is determined. The state change occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by a metal ball.

[0018] The metal ball is mounted on a base. The base can include a shallow circular structure and is further composed of a material with high coefficient of friction. In one example, the base can be composed of a rubber material.

[0019] The metal ball along with the base is enclosed in a housing that is bounded to the display device. The metal ball is configured to move along the base corresponding to orientation of the display device. Hence, the metal ball alters its positions based on the orientation of the display device.

[0020] The housing further includes a plurality of light sources. In one example, the light sources can include infrared (IR) light sources. Further, the housing includes a plurality of light sensors. Functions of the light sources and the light sensors are explained in detail in the following paragraphs.

[0021] The obstruction of light, from a corresponding pair of light sources, occurs in response to the change of position of the metal ball. The metal ball changes its position in response to change of the orientation of the display device.

[0022] In one example, a user may run a gaming application using the display device. During course of the gaming application, a user may change the orientation of the display device in order to alter a position of a gaming element, of the gaming application, on the display device.

[0023] Similarly, the state change for another pair of light sensors occurs as the position of the metal ball further changes.

[0024] The light sources are positioned along X-axis and Y-axis. Further, the light sensors are also positioned along the X-axis and the Y-axis.

[0025] Each light source, positioned along the X-axis including +ve X-axis and -ve X-axis, is associated with a corresponding light sensor positioned along the X-axis+ve X-axis and -ve X-axis. Hence, if the position of the metal ball is such that the metal ball obstructs the light source positioned along the X-axis then the state change occurs for the corresponding light sensor positioned along the X-axis.

[0026] Further, each light source, positioned along the Y-axis including +ve Y-axis and -ve Y-axis, is associated with a corresponding light sensor positioned along the Y-axis including +ve Y-axis and -ve Yaxis. Hence, if the position of the metal ball is such that the metal ball obstructs the light source positioned along the Y-axis then the state change occurs for the corresponding light sensor positioned along the Y-axis.

[0027] At step 115, a rotation angle and a tilt angle of the display device based on the state change of the pair of light sensors, caused by motion of the metal ball, is determined. A tilt angle conversion unit may be used to determine the rotation angle and the tilt angle. A plurality of rotation angle and tilt angle values corresponding to the state change of various pairs of light sensors are stored.

[0028] It should be noted that, number of the light sources and corresponding light sensors positioned along the X-axis and the Y-axis can be further incremented to determine rotation angle and tilt angle with minute angular values.

[0029] At step 120, an entity is controlled, on the display device, based on the rotation angle and the tilt angle. In one example, the entity is positioned, on the display device, based on the rotation angle and the tilt angle. Hence, the rotation angle and the tilt angle, of the metal ball with the base, correspond to the position of the image on the display device.

[0030] Further, in another example the orientation of the display device can be determined based on the rotation angle and the tilt angle computed.

[0031] In one embodiment, the housing can include a curvature such that the metal ball remains inside the curvature when the display device is tilted upside down.

[0032] In one example, the gaming element is positioned, on the display device, based on the rotation angle and the tilt angle computed in step 125. In another example, a photo displayed on the display device is rotated based on the rotation angle and the tilt angle. In yet another example, a mobile phone can be tilted such that the rotation angle and the tilt angle that is calculated corresponding to the tilt enable the user to browse next file stored in the mobile phone. Further, in another example, the rotation angle and the tilt angle that is calculated upon inverting the phone can be used to mute the phone. Similarly, the rotation angle and the tilt angle can be used for various such applications.

[0033] The method stops at step 125.

[0034] FIG. 2 is a block diagram of a display device for computing a rotation angle and a tilt angle for positioning an image on a display device, in accordance with one embodiment.

[0035] The display device 200 includes a bus 205 or other communication mechanism for communicating information, and a processor 210 coupled with the bus 205 for processing information. The display device 105 also includes a memory 215, for example a random access memory (RAM) or other dynamic storage device, coupled to the bus 205 for storing information and instructions to be executed by the processor 210. The memory 215 can be used for storing temporary variables or other intermediate information during execution of instructions by the processor 210. The display device 105 further includes a read only memory (ROM) 220 or other static storage device coupled to the bus 205 for storing static information and instructions for the processor 210. A storage unit 225, for example a magnetic disk or optical disk, is provided and coupled to the bus 205 for storing information, for example information associated with a change of position of a metal ball and state change for one or more pairs of light sensors.

[0036] The display device 200 can be coupled via the bus 205 to a display 230, for example a cathode ray tube (CRT), for displaying one or more images. The input device 235, including alphanumeric and other keys, is coupled to the bus 205 for communicating information and command selections to the processor 210. Another type of user input device is the cursor control 240, for example a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to the processor 210 and for controlling cursor movement on the display 230.

[0037] Various embodiments are related to the use of the display device 105 for implementing the techniques described herein. In some embodiments, the techniques are performed by the display device 200 in response to the processor 210 executing instructions included in the memory 215. Such instructions can be read into the memory 215 from another machine-readable medium, for example the storage unit 225. Execution of the instructions included in the memory 215 causes the processor 210 to perform the process steps described herein.

[0038] In some embodiments, the processor 210 can include one or more processing units for performing one or more functions of the processor 210. The processing units are hardware circuitry used in place of or in combination with software instructions to perform specified functions.

[0039] The term "machine-readable medium" as used herein refers to any medium that participates in providing data that causes a machine to perform a specific function. In an embodiment implemented using the display device 200, various machine-readable media are involved, for example, in providing instructions to the processor 210 for execution. The machine-readable medium can be a storage medium, either volatile or non-volatile. A volatile medium includes, for example, dynamic memory, such as the memory 215. A non-volatile medium includes, for example, optical or magnetic disks, for example the storage unit 225. All such media must be tangible to enable the instructions carried by the media to be detected by a physical mechanism that reads the instructions into a machine.

[0040] Common forms of machine-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic media, a CD-ROM, any other optical media, punchcards, papertape, any other physical media with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge.

[0041] In another embodiment, the machine-readable media can be transmission media including coaxial cables, copper wire and fiber optics, including the wires that include the bus 205. Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications. Examples of machine-readable media may include, but are not limited to, a carrier wave as described hereinafter or any other media from which the display device 200 can read. For example, the instructions can initially be carried on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to the display device 105 can receive the data on the telephone line and use an infrared transmitter to convert the data to an infra-red signal. An infra-red detector can receive the data carried in the infra-red signal and appropriate circuitry can place the data on the bus 205. The bus 205 carries the data to the memory 215, from which the processor 210 retrieves and executes the instructions. The instructions received by the memory 215 can optionally be stored on the storage unit 225 either before or after execution by the processor 210. All such media must be tangible to enable the instructions carried by the media to be detected by a physical mechanism that reads the instructions into a machine.

[0042] The display device 200 also includes a communication interface 245 coupled to the bus 205. The communication interface 245 provides a two-way data communication coupling to the processor 210. For example, the communication interface 245 can be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, the communication interface 245 can be a local area network (LAN) card to provide a data communication connection to a compatible LAN. In any such implementation, the communication interface 245 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

[0043] The processor 210 in the display device 200 is configured to determine a state change for a pair of light sensors, of a plurality of light sensors. The state change for the pair of light sensors occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by the metal ball. The obstruction of the light occurs in response to the change of position of the metal ball. Similarly, the state change for another pair of light sensors occurs as the position of the metal ball further changes since the light from another pair of light sources is obstructed by the metal ball.

[0044] The processor 210 is further operable to determine the rotation angle and the tilt angle, of the metal ball with a base, based on the state change of the pair of light sensors. The processor 210 further includes a tilt angle conversion unit 250 for determining the rotation angle and the tilt angle of the metal ball based on the state change of the pair of light sensors.

[0045] The processor 210 is also configured to store a plurality of rotation angle and tilt angles values based on the state change of the plurality of light sensors. The rotation angle and tilt angles values are used by the tilt angle conversion unit 250 for determining the rotation angle and the tilt angle of the metal ball.

[0046] Further the processor 210 is operable to control an entity, on the display device, based on the rotation angle and the tilt angle. In one example, a data processing unit 255 included in the processor 210 enables positioning of an image on the display device. Similarly, the data processing unit controls various entities, based on the rotation angle and the tilt angle of the metal ball, on the display device 105. The data processing unit 255 is coupled to the display 230 via the bus 205 for displaying the entities or images corresponding to the rotation angle and the tilt angle computed.

[0047] FIG. 3A-3B is an exemplary illustration of computing a rotation angle and a tilt angle when a metal ball 305 is positioned at centre of a base 310, in accordance with one embodiment.

[0048] FIG. 3A illustrates a side view of a housing 315 when the metal ball is positioned at the centre of the base 310. The metal ball 305 along with the base 310 is enclosed in the housing 315 that is bounded to the display device, for example the display device 200.

[0049] FIG. 3A also includes a plurality of light sources 320 positioned along X-axis and Y-axis of the housing 315. Further, the FIG. 3A includes a plurality of light sensors 325 positioned along the X-axis and the Y-axis of the housing 315. Each light source positioned along the X-axis including both +ve X-axis and -ve X-axis is associated to a corresponding light sensor positioned along the X-axis including both +ve X-axis and -ve X-axis. Further, each light source positioned along the Y-axis including both +ve Y-axis and -ve Y-axis is associated to a corresponding light sensor positioned along the Y-axis including both +ve Y-axis and -ve Y-axis.

[0050] FIG. 3B illustrates a top view of the housing 315 when the metal ball is positioned at the centre of the base 310. When the metal ball 305 is positioned at the centre of the base 310, then light emitted from a light source 330 along the -ve X-axis and the light emitted from a light source 335 along the +ve Y-axis is blocked by the metal ball 305.

[0051] As a result, a light sensor 345 corresponding to the light source 330 changes its state from state-1 to state-0 due to the blockage of the light, emitted from the light source 330, by the metal ball 305. Further, a light sensor 340 corresponding to the light source 335 also changes its state from the state-1 to the state-0 due to the blockage of the light, emitted from the light source 335, by the metal ball 305.

[0052] Hence, a tilt angle conversion unit determines the rotation angle and the tilt angle as 0° along the X-axis and 0° along the Y-axis since the light sensor 345 and the light sensor 340 have encountered the state change from the state-1 to the state-0. As a result an entity will be displayed at centre of a display of the display device.

[0053] Further, the tilt angle conversion unit determines the rotation angle and the tilt angle of the display device based on a scale 350. The scale 350 can be varied depending on application for which the rotation angle and the tilt angle are computed.

[0054] In one example, when it is determined that the metal ball is in the centre due to the rotation angle and the tilt angle as 0° along the X-axis and 0° along the Y-axis then it can be considered that the display device lies horizontally on a flat surface with the display of the display device facing upwards.

[0055] In yet another example, if none of the light sensors experience a state change then it can be considered that the display device is tilted upside-down.

[0056] In one embodiment, the housing can include a curvature such that the metal ball remains inside the curvature when the display device is tilted upside-down. The display device being tilted upside-down can be used to implement features for example, turn-on mute, turn-off display, or rejecting phone calls. Similarly, orientation of the display device can be used to obtain various features.

[0057] FIG. 4A-4B is an exemplary illustration for computing a rotation angle and a tilt angle when a metal ball is positioned at left corner of the base in accordance with one embodiment.

[0058] FIG. 4A illustrates a side view of the housing 315 when the metal ball 305 is positioned at the left corner of the base 310. The metal ball 305 along with the base 310 is enclosed in the housing 315 that is bounded to the display device, for example the display device 200.

[0059] FIG. 4A also includes the plurality of light sources 320 positioned along the X-axis and the Y-axis of the housing 315. Further, the FIG. 4A includes the plurality of light sensors 325 positioned along the X-axis and the Y-axis of the housing 315. Each light source positioned along the X-axis including both +ve X-axis and -ve X-axis is associated to a corresponding light sensor positioned along the X-axis that includes both +ve X-axis and -ve X-axis. Further, each light source positioned along the Y-axis including both +ve Y-axis and -ve Y-axis is associated to a corresponding light sensor positioned along the Y-axis that includes both +ve Y-axis and -ve Y-axis.

[0060] FIG. 4B illustrates a top view of the housing 315 when the metal ball 305 is positioned at the left corner of the base 310. When the metal ball 305 is positioned at the left corner of the base 310, then light emitted from a light source 355 along the -ve X-axis and the light emitted from a light source 360 along the +ve Y-axis is blocked by the metal ball 305.

[0061] As a result, a light sensor 370 corresponding to the light source 355 changes its state from state-1 to state-0 due to the blockage of the light, emitted from the light source 355, by the metal ball 305. Further, a light sensor 365 corresponding to the light source 360 also changes its state from the state-1 to the state-0 due to the blockage of the light, emitted from the light source 360, by the metal ball 305.

[0062] Hence, a tilt angle conversion unit determines the rotation angle and the tilt angle of the display device as -80° along the X-axis and -20° along the Y-axis since the light sensor 365 and the light sensor 370 have encountered the state change from the state-1 to the state-0. As a result an entity will be displayed at a position -80° along the X-axis and -20° along the Y-axis on the display device.

[0063] In one example, when it is determined that the metal ball 305 is positioned at the left corner of the base 310 then it can be considered that the display device lies horizontally but tilted towards the left.

[0064] Similarly, various entities are positioned on the display of the display device based on the rotation angle and the tilt angle of the metal ball 305 with the base 310.

[0065] Advantageously, the embodiments specified in the present disclosure provide an efficient method of computing the rotation angle and the tilt angle of a metal ball for controlling entities on a display device. As the entities are positioned based on rotation angle and the tilt angle of the metal ball, by using the light sources and the light sensors, the need for accelerometer and gyroscope for computing the rotation angle and the tilt angle is eliminated, thereby making it cost effective. Further, the present disclosure enables a method to compute the rotation angle and the tilt angle with minute values by increasing the number of the light sources and the corresponding light sensors.

[0066] In the preceding specification, the present disclosure and its advantages have been described with reference to specific embodiments. However, it will be apparent to a person of ordinary skill in the art that various modifications and changes can be made, without departing from the scope of the present disclosure, as set forth in the claims below. Accordingly, the specification and figures are to be regarded as illustrative examples of the present disclosure, rather than in restrictive sense. All such possible modifications are intended to be included within the scope of present disclosure.

I/We claim:

1. A method of computing a rotation angle and a tilt angle, by employing an opto-mechanical technique, on a display device the method comprising:

determining a state change for a pair of light sensors, of a plurality of light sensors, wherein the state change occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by the metal ball;

determining the rotation angle and the tilt angle, of the metal ball with a base, based on the state change of the pair of light sensors; and

controlling an entity, on the display device, based on the rotation angle and the tilt angle.

2. The method as claimed in claim 1, wherein the metal ball mounted on the base.

3. The method as claimed in claim 1, wherein the metal ball and the base is enclosed in a housing that is bounded to the display device.

4. The method as claimed in claim 1, wherein the base comprises a shallow circular structure composed using a material of high coefficient of friction.

5. The method as claimed in claim 1, wherein the change of position of the metal ball occurs due to change of orientation of the display device.

6. The method as claimed in claim 1, wherein the plurality of light sources is positioned along X-axis and Y-axis.

7. The method as claimed in claim 1, wherein the plurality of light sensors is positioned along X-axis and Y-axis.

8. The method as claimed in claim 1, wherein each light source of the plurality of light sources, along X-axis, is associated with a corresponding light sensor of the plurality of light sensors along the X-axis.

9. The method as claimed in claim 1, wherein each light source of the plurality of light sources, along Y-axis, is associated with a corresponding light sensor of the plurality of light sensors along the Y-axis.

10. The method as claimed in claim 1, wherein the change of position of the metal ball leads to the obstruction of light emitted from the corresponding pair of light sources included in the plurality of light sources.

11. The method as claimed in claim 1 and further comprising:
storing a plurality of rotation angle and tilt angles values based on the state change of the plurality of light sensors.

12. A system for computing a rotation angle and a tilt angle, by employing an opto¬
mechanical technique, on a display device, the system comprising:

a communication interface for establishing communication;
a memory that stores instructions; and
a processor responsive to the instructions to determine a state change for a pair of light sensors, of a plurality of light sensors, wherein the state change occurs due to obstruction of light, from a corresponding pair of light sources, of a plurality of light sources, by a metal ball;
determine the rotation angle and the tilt angle, of the metal ball with a base, based on the state change of the pair of light sensors; and
control an entity, on the display device, based on the rotation angle and the tilt angle.

13. The system as claimed in claim 1, wherein the processor further comprises a tilt angle conversion unit for determining the rotation angle and the tilt angle of the metal ball based on the state change of the pair of light sensors.

14. The system as claimed in claim 1, wherein the processor further comprises a data processing unit to control the entity, on the display device, based on the rotation angle and the tilt angle.

15. The system as claimed in claim 1, wherein the processor is further configured to store a plurality of rotation angle and tilt angles values based on the state change of the plurality of light sensors.