Wireless video transmitter

• US 8,732,769 B2
• Filed: 05/20/2010
• Issued: 05/20/2014
• Est. Priority Date: 07/03/2009
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi Consumer Electronics Company Limited (Hitachi, Ltd.)
• Inventors: Ogi, Yuya, Kabuto, Nobuaki
• Primary Examiner(s): Alam, Mushfikh
• Assistant Examiner(s): PIERORAZIO, MICHAEL
• Application Number:
  US12/784,118
• Publication Number:
  US 20110004909A1
• Time in Patent Office: 1,461 Days
• Field of Search: 348/734, 725/81, 725133-153
• US Class Current: 725/81
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/41265 having a remote control device for bidirectional communication between the remote control device and client device unidirectional remote control device H04N21/42204
• CPC Class Codes: H04N 21/42204 User interfaces specially adapted for controlling a client device through a remote control device; Remote control devices therefor constructive details of casings for the remote control device H01H9/0235; user interfaces for controlling a tuning device of a television receiver through a remote control H03J9/00; remote control of peripheral devices connected to a television receiver through the remote control device of the television receiver H04B1/205
• CPC Class Codes: H04N 21/42208 Display device provided on the remote control
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 7/088 the inserted signal being digital
• CPC Class Codes: H04N 7/106 for domestic distribution
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

A technique is offered which is applied to a system for wirelessly sending and receiving control commands and which permits mutual communications owing to the control commands between a wireless video transmitter and wireless video receivers to be operated stably with low delay. The transmitter makes a decision as to whether commands received from the receivers are certain commands. If so, the transmitter assigns transmissible periods, in which the receivers can send commands, more preferentially to the wireless video receiver that has sent out the certain commands than the other wireless video receivers.

Claims

1. A video transmitter for wirelessly sending a video signal to a plurality of video receivers, the video transmitter comprising:

a receiver portion configured to receive a command from any one of the plurality of video receivers; and

a control portion configured to determine whether or not the command received by the receiver portion of the video transmitter is a given command, wherein;

a vertical retrace period of each frame of the video signal wirelessly sent by the video transmitter is assigned as a transmissible period for sending a command from each of the plurality of video receivers to the video transmitter;

when the control portion of the video transmitter determines the received command is the given command, during a command transmission period in which all of the plurality of video receivers can transmit commands, in response to the received given command, the control portion of the video transmitter assigns the transmissible periods for each of the video receivers per the vertical retrace period such that more transmissible periods are assigned to the video receiver that has sent out the received given command than to other video receivers;

each frame of the video signals includes a header;

the header of each frame of the video signals includes an identification (ID) number of one of the plurality of video receivers;

the vertical retrace period of each frame of the video signals is assigned as the transmissible period of the video receiver which corresponds to the ID number included in the header of each frame of the video signals; and

when the control portion of the video transmitter determines that the received command is a given command, the control portion of the video transmitter, during the command transmission period, changes the ID number of the header such that the number of headers having the ID number corresponding to the video receiver transmitting the given command is more than the number of headers having an ID number corresponding to the other video receiver.

2. The video transmitter as set forth in claim 1, wherein the command transmission period is a period of frame numbers equal to the number of the video receivers.

3. The video transmitter as set forth in claim 2, wherein when a command associated with transmission of a remote control signal is received, the control portion of the video transmitter assigns the transmissible periods preferentially to the video receiver that has sent out the command associated with the transmission of the remote control signal during a given period of time or until a remote control canceling command is received.

4. The video transmitter as set forth in claim 3, wherein the preferentially assigned transmissible periods are fewer in number than the number of the plurality of the video receivers.

5. The video transmitter as set forth in claim 1, wherein:

the transmissible periods are assigned preferentially and periodically at a first rate when a measured time since the reception of the command is between 0 ms and 350 ms;

the transmissible periods are assigned preferentially and periodically at a second rate when the measured time since the reception of the command is greater than 350 ms and less than or equal to 600 ms, and the measured time is within a given interval of time during the reception of the command, and

the second rate is higher than the first rate.

9. The video transmitter as set forth in claim 2, wherein the control portion of the video transmitter assigns one video receiver during one vertical retrace period when the frame frequency of the video signal is in excess of 30 Hz and assigns at least two video receivers during one vertical retrace period when the frame frequency is equal to or lower than 30 Hz.

10. The video transmitter as set forth in claim 2, wherein during the command transmission period in which all of the video receivers can transmit commands, the vertical retrace periods assigned to the video receiver that has sent out the given command are increased in number to thereby extend a total period of the transmissible periods for the video receiver that has sent out the given command.

6. A video transmitter for sending a video signal to at least one or more video receivers, the video transmitter comprising:

a transceiver portion configured to receive a command from the at least one or more video receivers and to send a command to the at least one or more video receivers; and

a control portion configured to assign a transmissible period to be used for transmitting the command, wherein;

when the command received from the at least one or more video receivers or the command transmitted to the transceiver portion is a given command during a command transmission period in which all of the video receivers can transmit commands, in response to the given command, the control portion of the video transmitter assigns a transmissible period of a video receiver per a vertical retrace period of a frame of the video signal in such a way that more transmissible periods are assigned to the video receiver that has sent out the given command than to any other video receivers;

the frame of the video signal includes a header;

the header of the frame of the video signal includes an identification (ID) number of one of the plurality of video receivers;

the vertical retrace period of the frame of the video signal is assigned as the transmissible period of the video receiver which corresponds to the ID number included in the header of the video signal; and

when the control portion of the video transmitter determines that the received command is a given command, the control portion of the video transmitter, during the command transmission period, changes the ID number of the header such that the number of headers having the ID number corresponding to the video receiver transmitting the given command is more than the number of headers having an ID number corresponding to the other video receiver.

7. The video transmitter as set forth in claim 6, wherein the command transmission period is a period of frame numbers equal to the number of the at least one or more video receivers.

8. The video transmitter as set forth in claim 7, wherein when a command asking for a reply is sent from the video transmitter, the command transmission periods are preferentially assigned to the video receiver receiving the command asking for a reply during a given interval of time or until the reply is received.

11. The video transmitter as set forth in claim 7, wherein the control portion of the video transmitter assigns one video receiver during one vertical retrace period when the frame frequency of the video signal is in excess of 30 Hz and assigns at least two video receivers during one vertical retrace period when the frame frequency is equal to or lower than 30 Hz.