Patent Publication Number: US-2013235170-A1

Title: Electronic Apparatus and Method Utilized in Stereo Glasses

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION 
     This patent application is based on Taiwan, R.O.C. patent application No. 101107839, filed Mar. 8, 2012. 
     FIELD OF THE INVENTION 
     The present invention relates to a synchronization mechanism for stereo glasses, and more particularly, to an electronic apparatus and method applied to a pair of stereo glasses for synchronizing corresponding frames with shutter glasses. 
     BACKGROUND OF THE INVENTION 
     A current mainstream three-dimension (3D) stereo display apparatus applies an interlacing display mode to separate a left-eye image and a right-eye image, i.e., the left-eye image and the right-eye image are displayed in an interfacing fashion, so that a user can observe a 3D film via a pair of shutter stereo glasses. The pair of shutter stereo glasses needs to continuously receive synchronization signals transmitted from a display apparatus or a transmission apparatus externally coupled to the display apparatus, so as to synchronize an open/closed status of a left-eye/right-eye shutter glass with timing of left-eye/right-eye frames to be displayed by the display apparatus via the synchronization signal. Once the stereo glasses cannot successfully receive the synchronization signal since the synchronization signal is stopped or interfered due to the transmission mechanism characteristics, the open/closed status of the left-eye/right-eye shutter glass of the pair of shutter glasses cannot be synchronized with timing of the left-eye/right-eye frames to be displayed by the display apparatus, and significant crosstalk is created in the frame which is observed by the user, deteriorating image quality or even causing a failure of displaying a stereo image. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an electronic apparatus and a method applied to stereo glasses to solve the foregoing problem. 
     According to an embodiment of the present invention, an electronic apparatus comprises a first receiver, a second receiver, and a synchronization controller. The first receiver receives a first synchronization signal, and the second receiver receives a second synchronization signal. A transmission mechanism of the second synchronization signal is different from that of the first synchronization signal. The synchronization controller coupled to the first receiver and the second receiver synchronizes a left-eye/right-eye shutter glass of a pair of stereo glasses with a corresponding left-eye/right-eye frame of a stereo image according to at least one of the first and second synchronization signals. 
     According to another embodiment of the present invention, a method comprises receiving a first synchronization signal; receiving a second synchronization signal having a transmission mechanism different from that of the first synchronization signal; and synchronizing a left-eye/right-eye shutter glass of a pair of stereo glasses with a corresponding left-eye/right-eye frame of a stereo image according to at least one of the first and second synchronization signals. 
     According to yet another embodiment, a method applied to a pair of stereo glasses comprising a first receiver and a second receiver is provided. The method comprises determining whether the first receiver receives a first synchronization signal; synchronizing a left-eye/right-eye shutter glass of the pair of stereo glasses with a corresponding left-eye/right-eye frame of a stereo image according to the first synchronization signal when the first receiver receives the first synchronization signal; and activating the second receiver to receive a second synchronization signal and synchronizing the left-eye/right-eye shutter glass of the stereo glasses with the corresponding left-eye/right-eye frame of the stereo image according to the second synchronization signal when the first receiver does not receive the first synchronization signal. 
     In addition, according to the present invention, different transmission mechanisms are applied to achieve a cooperative stereo glasses synchronization control mechanism. For example, the first receiver is an infrared receiver, and the second receiver is a frequency-modulation (FM) receiver. Except for the pair of stereo glasses, an FM transmitter is externally coupled to the display apparatus. Since the FM transmission mechanism can make up for disadvantages of infrared transmission mechanism due to the advantage that the FM transmission has a signal receiving range, a data transmission amount and transmission characteristics different from those of the infrared transmission mechanism, the pair of stereo glasses is capable of receiving a synchronization signal transmitted via the FM transmission mechanism while failing to receive the synchronization signal transmitted via the infrared transmission mechanism, so as to reduce power consumption as well as maintaining synchronization of the left-eye/right-eye shutter glass of the pair of stereo glasses and the corresponding left-eye/right-eye frame of the stereo image. Therefore, according to the present invention, not only the synchronization signal transmitted via the infrared transmission mechanism but also the synchronization signal transmitted via the FM transmission mechanism can be received at the end of the pair of stereo glasses, so that the disadvantage of single transmission mechanism is overcame through the cooperative stereo glasses synchronization control mechanism based on different transmission mechanisms. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and spirit related to the present invention can be further understood via the following detailed description and drawings. 
         FIG. 1  is a schematic diagram of an electronic apparatus applied to a pair of stereo glasses in accordance with an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of detailed circuits of a synchronization controller, a first receiver and a second receiver of the electronic apparatus disclosed in  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 3  is a schematic diagram of a first synchronization signal S 1  disclosed in  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 4  is a schematic diagram of switch statuses of receiving modes of the electronic apparatus disclosed in  FIG. 1  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Refer to  FIG. 1  showing an electronic apparatus  100  applied to a pair of stereo glasses  105  in accordance with an embodiment of the present invention. The electronic apparatus  100  comprises a first receiver  110 A, a second receiver  110 B, a synchronization controller  115 , and a power management unit  120 . The first receiver  110 A receives a first synchronization signal S 1 , and the second receiver  110 B receives a second synchronization signal S 2  having a transmission mechanism different from that of the first synchronization signal S 1 . The synchronization controller  115  coupled to the first receiver  110 A and the second receiver  110 B synchronizes a left-eye shutter glass  125 A or a right-eye shutter glass  125 B of the pair of stereo glasses  105  with a corresponding left-eye or right-eye frame of a stereo image according to at least one of the first synchronization signal and the second synchronization signal. The power management unit  120  coupled to the second receiver  110 B and the synchronization controller  115  controls a power supply status of the second receiver  110 B according to a switch control signal SC outputted by the synchronization controller  115 . According to the present invention, the first synchronization signal S 1  adopts a directional transmission mechanism, and the second synchronization signal S 2  adopts a non-directional transmission mechanism. For example, the first synchronization signal S 1  is an infrared signal, and the second synchronization signal S 2  is an FM signal or a Bluetooth signal. That is to say, the pair of stereo glasses  105  has a capability of receiving two paths of synchronization signals that are transmitted via two different transmission mechanisms. The two paths of synchronization signals are received and modulated to synchronize the left-eye shutter glass  125 A or the right-eye shutter glass  125 B of the pair of stereo glasses  105  with the corresponding left-eye or right-eye frame of the stereo image. Therefore, once a shutter glass is synchronized with a frame, the synchronization controller  115  performs synchronization according to only one of the first synchronization S 1  and the second synchronization S 2 . According to the present invention, in order to maintain high display quality of the stereo image, the first receiver  110 A and the second receiver  110 B of the electronic apparatus  100  receives different synchronization signals respectively, so that the electronic apparatus  100  is still capable of receiving another synchronization signal to perform synchronization of an open/closed status of the shutter glass and the corresponding frame when the electronic apparatus fails to receive a certain synchronization signal (e.g., possibly being stopped or interfered). Therefore, the synchronization controller  115  continues to output proper control signals to control the open/closed status of the left-eye shutter glass  125 A and the right-eye shutter glass  125 B by dynamically referring to the first synchronization signal S 1  or the second synchronization signal S 2 , so as to accurately synchronize timing of the left-eye/right-eye shutter glass  125 A/ 125 B and the left-eye/right-eye frame of the pair of stereo image. Accordingly, the left-eye/right-eye shutter glass  125 A/ 125 B is accurately opened or closed during each timing sequence due to the abovementioned synchronization, so that human eyes can see appropriate left-eye/right-eye frames to observe an appropriate stereo image during each timing sequence without getting any uncomfortable feelings. 
     In addition, since the pair of stereo glasses  105  is a portable apparatus, a power supply unit is adopted to provide power supply to internal circuits. Therefore, in order to achieve an object of reducing power consumption in the condition that two receivers are applied to the pair of stereo glasses, the first receiver  110 A and the second receiver  110 B even adopts different transmission mechanisms having different power consumptions. For example, the first receiver  110 A consumes less power, and the second receiver  110 B consumes relatively more power. When the first synchronization signal S 1  and the second synchronization S 2  are received and detected, only the first receiver  110 A is activated to reduce power consumption, i.e., the power supply unit of the pair of stereo glass  105  only provides a power supply to the first receiver  110 A but not the second receiver  110 B. When the first receiver  110 A cannot receive the first synchronization signal S 1  that is stopped or interfered, the second receiver  110 B is activated, and the power supply unit starts to provide power supply to the second receiver  110 B, such that the second receiver  110 B receives the second synchronization signal S 2  while the power supply of the first receiver  110 A is cut off. As mentioned above, the first receiver  110 A is an infrared receiver and the second receiver  110 B is an FM receiver or a Bluetooth receiver, and infrared transmission mechanism is directional and the FM or Bluetooth transmission mechanism is non-directional. Therefore, when the first receiver  110 A cannot successfully receive the first synchronization signal S 1  for the reason that infrared lines is stopped or interfered (e.g., when a person passes by), the second receiver  110 B of the electronic apparatus  100  is activated or enabled in time to receive the second synchronization signal S 2 , such that the synchronization controller  115  is able to instantly synchronize timing of the open/closed status of the shutter glasses and frames thus guaranteeing accurate stereo image preservation of human eyes without getting any uncomfortable feelings. 
     The power management unit  120  is in charge of activating or deactivating the second receiver  110 B. When the first receiver  110 A cannot successfully receive or detect the first synchronization signal S 1  during a predetermined time period, meaning that the first synchronization signal S 1  is stopped or interfered, the first receiver  110 A informs the synchronization controller  115  after the predetermined time period. Upon being informed by the first receiver  110 A, the synchronization controller  115  outputs a switch control signal to the power management unit  120  so as to maintain synchronizing the open/closed statuses of the shutter glasses with the frames. When the switch controls signal is received, the power management unit  120  enables and activates the second receiver  110 B to receive the second synchronization signal S 2 . Since the transmission mechanism of the second synchronization signal S 2  is non-directional, the second synchronization signal S 2  is neither stopped nor interfered, such that the second receiver  110 B receives the second synchronization signal S 2  and the synchronization controller  115  can still synchronize the open/closed statues of the shutter glasses with the frames according to the second synchronization signal S 2  received by the second receiver  110 B even if the first receiver  110 A cannot successfully receive the first synchronization signal S 1 . In addition, when the first receiver  110 A successfully receives or detects the first synchronization signal S 1 , the first receiver  110 A informs the synchronization controller  115 , such that the synchronization controller  115  outputs the switch control signal to the power management unit  120  to cut off the power supply of the second receiver  110 B so as to achieve the object of reducing power consumption. When the switch control signal is received, the power management unit  120  cuts off the power supply of the second receiver  110 B to stop receiving the second synchronization signal S 2 , thus reducing power consumption. For example, the power management unit  120  cuts off the power supply of the entire second receiver  110 B based on the object of reducing power consumption; however, when other design objects are taken into consideration (e.g., an object of rapidly activating the second receiver  110 B for the next time), the power management unit  120  decreases the power supply of the second receiver  110 B instead of cutting off the power supply of the entire second receiver  110 B. For the power supply unit of the pair of stereo glasses  105 , the object of reducing power consumption is also achieved regardless of whether the power supply of the entire or a part of the second receiver  110 B is cut off. In another embodiment, the synchronization controller  115  detects whether the first receiver  110 A receives the first synchronization signal S 1 , i.e., the synchronization controller  115  continuously detects whether the first receiver  110 A receives the first synchronization signal S 1 . When the first receiver  110 A does not receive the first synchronization signal S 1  during a predetermined time period, the synchronization controller  115  transmits a switch control signal to the power management unit  120  to activate or enable the second receiver  110 B. When the first receiver  110 A again receives the first synchronization signal S 1 , the synchronization controller  115  transmits a switch control signal to the power management unit  120  to turn down the second receiver  110 B. In addition, the foregoing predetermined time period is determined according to an activating speed of the second receiver  110 B, and open/closed time interval of the pair of stereo glasses  105  or other experimental data. For example, when an experimental data indicates that no synchronization signal is detected during a time period T 1 , synchronization is failed, so that a predetermined time period T 2  is designed as being smaller than the time period T 1 , i.e., when the first synchronization signal S 1  is yet not received after the predetermined time period T 2 , it means that there is a high probability of synchronization failure. At this point, the second receiver  110 B is activated to receive the second synchronization signal S 2  and the synchronization controller  115  changes to perform synchronization according to the received second synchronization signal S 2 , i.e., synchronization is performed in advance according to the second synchronization signal S 2  when the synchronization failure is not yet confirmed. Accordingly, continuous synchronization of the open/closed status of the pair of stereo glasses  105  and the frames is maintained, and thus guaranteeing high quality of observation. 
     Referring to  FIG. 2 , a schematic diagram of detailed circuits of the synchronization controller  115 , the first receiver  110 A, and the second receiver  110 B of the electronic apparatus  100  disclosed in  FIG. 1  is shown in accordance with an embodiment of the present invention. For example, the first receiver  110 A (e.g., an infrared receiver) comprises a synchronization detecting unit  202  and a first timing signal generating unit  204 . The second receiver  110 B (e.g., an FM receiver) comprises a second timing signal generating unit  206 , and the synchronization controller  115  comprises a control unit  208  and a signal generating unit  210  that comprises a multiplexer MUX. With respect to the first synchronization signal S 1  (i.e., an infrared signal) reception, since a transmission amount of infrared modulation transmission is small, an infrared data from the display apparatus or an external transmitter cannot directly transmit an image (e.g., a frame) playing frequency of the display apparatus or corresponding open/closed adjustment of the pair of stereo glasses  105 . Therefore, the synchronization detecting unit  202  detects the first synchronization signal S 1  and generates a result representing the image playing frequency and the corresponding open/closed adjustment of the pair of stereo glasses  105 . Referring to  FIG. 3 , a schematic diagram of the first synchronization signal S 1  in  FIG. 1  in accordance with an embodiment of the present invention is shown. The first synchronization signal S 1  comprises commands L_ON, L_OFF, R_ON, and R_OFF respectively representing corresponding switch timing sequences of the open/closed statuses of the left-eye shutter glass  125 A and the right-eye shutter glass  125 B of the pair of stereo glasses  105 . For example, the command L_ON indicates that the left-eye shutter glass  125 A is opened at a time point t 1 , the command L_OFF indicates that the left-eye shutter glass  125 A is closed at a time point t 2 , the command R_ON indicates that the right-eye shutter glass  125 B is opened at a time point t 3 , and the command R_OFF indicates that the right-eye shutter glass  125 B is closed at a time point t 4 . The synchronization detecting unit  202  detects/counts the number of commands contained in the first synchronization signal S 1  during a predetermined time period to calculate respective average open time, average closed time, average cycle of the open command, and the average cycle of the closed command of the left-eye shutter glass  125 A and the right-eye shutter glass  125 B. The average open/closed time and the average cycle of the open/closed command represent result information of the image playing frequency and corresponding shutter open/closed adjustment of the pair of stereo glasses  105 . The result information is outputted from the synchronization detecting unit  202  to the first timing signal generating unit  204 . The first timing signal generating unit  204  generates a timing signal for practical synchronization according to the result information, and outputs the timing signal to the multiplexer MUX of the signal generating unit  210  of the synchronization controller  115 . Therefore, once the first receiver  110 A fails to receive the first synchronization signal S 1  that is stopped or interfered, the multiplexer MUX does not receive the foregoing timing signal. 
     With respect to FM signal reception, since a data transmission amount of FM modulation transmission is relatively large, an FM data from the display apparatus or an external transmitter can directly transmit an image (e.g., a frame) playing frequency of the display apparatus and corresponding shutter open/closed adjustment of the pair of stereo glasses  105 . Therefore, a synchronization detecting unit is no longer needed for detecting the second synchronization signal S 2  to generate result information representing the image playing frequency and the corresponding shutter open/closed adjustment of the pair of stereo glasses  105 . The second timing signal generating unit  206  directly generates the timing signal for practical synchronization according to the image playing frequency and the corresponding shutter open/closed adjustment of the pair of stereo glasses  105  contained in the second synchronization signal S 2 , and outputs the timing signal to the multiplexer MUX of the signal generating unit  210  of the synchronization controller  115 . 
     The control unit  208  of the synchronization controller  115  detects operation status of the first receiver  110 A (or a signal from any circuit component of the first receiver  110 A) to determine whether the first synchronization signal S 1  is stopped or interfered, and appropriately controls switch of the multiplexer MUX. For example, the multiplexer MUX selects a timing signal generated from the first timing signal generating unit  204  as an output to generate open/closed adjustment signals S_L and S_R of the left-eye/right-eye shutter glass  125 A/ 125 B of the pair of stereo glasses  105 . In other embodiment, the control unit  208  counts a time length of the interval which the timing signal generated by the first timing signal generating unit  204  does not be received, and determines that the first synchronization signal S 1  cannot be currently successfully received once the time length beyond the predetermined time period T 2 . At this point, in order to maintain continuous synchronization, the control unit  208  transmits a switch control signal SC to the power management unit  120  to activate power supply of the second receiver  110 B. Therefore, the second timing signal generating unit  206  is activated and generates the timing signal for synchronization according to the foregoing result information contained in the second synchronization signal S 2 . At this point, the control unit  208  transmits a control signal to the multiplexer MUX, which performs switching to select the timing signal generated by the second timing signal generating unit  206  as an output, so as to generate subsequent open/closed adjustment signals S_L and S_R for controlling the left-eye shutter glass  125 A and the right-eye shutter glass  125 B of the pair of stereo glasses  105 . In other words, the control unit  208  determines whether to change from an infrared receiving mode of the first receiver  110 A to an FM receiving mode of the second receiver  110 B. In addition, the control unit  208  also determines whether to switch from the FM receiving mode of the second receiver  110 B to the infrared receiving mode of the first receiver  110 A. For example, when the timing signal generated by the first timing signal generating unit  204  is detected again, the control unit  208  determines that the first synchronization signal S 1  is currently successfully received, and transmits the switch control signal SC to the power management unit  120  to cut off the power supply of the second receiver  110 B so as to achieve the object of reducing power consumption. Therefore, the second timing signal generating unit  206  is closed, and the control unit  208  also transmits a control signal to the multiplexer MUX to switch and select the timing signal generated by the first timing signal generating unit  204  as an output, so as to generate the subsequent open/closed adjustment signal S_L and S_R of the left-eye shutter glass  125 A and the right-eye shutter glass  125 B of the pair of stereo glasses  105 . It is to be noted that, since power consumption of the second timing signal generating unit  206  is limited, when the power management unit  120  selects to reduce the power supply of the second receiver  110 B, only power supplies of other circuit components of the second receiver  110 B are cut off while the power supply of the second timing signal generating unit  206  is still remained. In other words, the power management unit  120  cuts off power supply to a part of circuit components of the second receiver  110 B to achieve the object of reducing power consumption. 
     In other embodiment, in order to achieve the object of simplifying operation design as well as reducing power consumption, the power management unit  120  provides the power supply of the second receiver  110 B according to the switch control signal SC outputted from the synchronization controller  115 , so as to periodically or intermittently activate the second receiver  110 B, i.e., activation or deactivation operations of the second receiver  110 B has no relation with the result of whether the first synchronization signal S 1  is successfully received. The second receiver  110 B is designed as being periodically activated to receive and modulate the second synchronization signal S 2 . Accordingly, since the synchronization controller  115  periodically receives the second synchronization signal S 2  that is received and outputted by the second receiver  110 B, the synchronization controller  115  selects to perform synchronization of the open/closed status of the shutter glasses and frames according to the second synchronization signal S 2  once the first synchronization signal S 1  is stopped or interfered when the second receiver  110 B is activated. Therefore, a possibility of continuous synchronization of the open/closed status of the shutter glasses and the frames is increased. In addition, in an embodiment, the power supply of the second receiver  110 B is periodically turned on or cut off, and the power supply of the first receiver  110 A remains being turned on. However, in another embodiment, in order to reduce power consumption, when the power supply of the second receiver  110 B is turned on, the power supply of the first receiver  110 A is cut off; and when the power supply of the second receiver  110 B is cut off, the power supply of the first receiver  110 A is turned on. 
     It is to be noted that, the first receiver  110 A is an infrared receiver, and the second receiver  110 B is an FM receiver or a Bluetooth receiver in the foregoing embodiments for illustration purposes. Under the premise of not departing from the spirit of the present invention, operations of the first receiver  110 A (e.g., demodulation of the first synchronization signal S 1 ) only need to be different from those of the second receiver  110 B (e.g., demodulation of the second synchronization signal S 2 ), so that the synchronization controller  115  can still perform synchronization of the open/closed status of the shutter glasses and the frames according to another synchronization signal (e.g., the synchronization signal S 2 ) when the synchronization controller  115  cannot refer to one synchronization signal (e.g., the synchronization signal S 1 ). Therefore, the first receiver  110 A and the second receiver  110 B are not limited to the infrared receiver, the FM receiver or the Bluetooth receiver, and other types of wireless receiver are also applied to the present invention. In addition, the foregoing first synchronization signal S 1  and the second synchronization signal S 2  are transmitted from a display apparatus having a stereo image display function or a wireless signal transmitter that is externally coupled to the display apparatus; however, it shall be construed as limiting the present invention. 
     For reader convenience, referring to  FIG. 4 , a schematic diagram of switch statuses of receiving modes of the electronic apparatus  100  disclosed in  FIG. 1  in accordance with an embodiment of the present invention is shown. A status  402  represents that the first receiver  110 A and the second receiver  110 B of the electronic apparatus  100  cannot receive the first synchronization signal S 1  and the second synchronization signal S 2 , or the display apparatus or a transmitter externally coupled to the display apparatus does not transmit any synchronization signal (i.e., an image displayed by the display apparatus is not a stereo image). A status  404  represents that the electronic apparatus  100  in an infrared signal receiving mode of the first receiver  110 A can successfully receive the first synchronization signal S 1  and cuts off the power supply of the second receiver  110 B. A status  406  represents that the electronic apparatus  100  in an FM signal receiving mode of the second receiver  110 B cannot receive the first synchronization signal S 1 , but the electronic apparatus  100  can successfully receive the second synchronization signal S 2 . Therefore, the electronic apparatus  100  is designed as being in the infrared signal receiving mode of the first receiver  110 A (i.e., status  404 ) in advance. Once the pair of stereo glasses  105  is activated, when the first synchronization signal S 1  and the second synchronization signal S 2  cannot be successfully received or no synchronization signal is detected (‘IR=0 and FM=0’), the electronic apparatus  100  changes from the status  404  to the status  402 . When the first synchronization signal is not received and the second synchronization signal S 2  is successfully received (‘IR=0 and FM=1’), the electronic apparatus  100  changes from the status  404  to the status  406 . When the electronic apparatus  100  is in the status  402 , in the event that the first synchronization signal S 1  is successfully received (‘IR=1’), the electronic apparatus  100  changes from the status  402  to the status  404 ; and in the event that the first synchronization signal S 1  is not received and the second synchronization signal S 2  is successfully received (‘IR=0 and FM=1’), the electronic apparatus  100  changes from the status  402  to the status  406 . In addition, when the electronic apparatus  100  is in the status  406 , in the event that the first synchronization signal S 1  and the second synchronization signal S 2  cannot be successfully received or no synchronization signal is detected (‘IR=0 and FM=0’), the electronic apparatus  100  changes from the status  406  to the status  402 ; and in the event that the first synchronization signal S 1  is successfully received (‘IR=1’), the electronic apparatus  100  changes from the status  406  to the status  404 . 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not to be limited to the above embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.