WIRELESS VIDEO TRANSMITTER

• US 20110004909A1
• Filed: 05/20/2010
• Published: 01/06/2011
• Est. Priority Date: 07/03/2009
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Inventors: OGI, Yuya, Kabuto, Nobuaki
• Granted Patent: US 8,732,769 B2
• Time in Patent Office: Days
• 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 plural video receivers, comprising:

a receiver portion which receives a command from any one of the video receivers; and

a control portion which makes a decision as to whether or not the command received by the receiver portion is a given command;

wherein when the received command is the given command, the control portion assigns more transmissible periods in which the video receiver can send out commands to the video receiver that has sent out the given command than other video transmitters.

2. The video transmitter as set forth in claim 1, wherein the transmissible periods are vertical retrace periods of a video signal in which the first-mentioned video transmitter transmits wirelessly, and wherein the control portion controls the assignment to the plural video receivers during each of the vertical retrace periods.

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 assigns the transmissible periods preferentially to the video transmitter that has sent out this command during a given period 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 video receivers.

5. The video transmitter as set forth in claim 1, wherein the transmissible periods assigned after a lapse of 350 ms to 600 ms since the reception of the command within a given interval of time during reception of the command are made greater in number than the transmissible periods assigned after a lapse of 0 ms to 350 ms.

9. The video transmitter as set forth in claim 2, wherein the control signal 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 wireless 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 a 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 the 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 video receiver, comprising:

a receiver portion which receives a command from the video receiver;

a control portion which controls the timing at which the command is sent by the video receiver; and

a sending portion which sends commands and a transmission timing control signal indicated by the control portion to the video receiver;

wherein in response to a given command sent by the sending portion, periods assigned to the video receiver receiving the command are increased in total length of time during a given interval of time.

7. The video transmitter as set forth in claim 6,

wherein the at least one video receiver is plural in number,

wherein command transmission periods for the video receivers are vertical retrace periods, and

wherein the control portion controls the assignment to the video receivers during each of the vertical retrace periods.

8. The video transmitter as set forth in claim 7, wherein when a command asking for a reply is sent, the command transmission periods are preferentially assigned to the video receiver receiving this command 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 signal 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 wireless video receivers during one vertical retrace period when the frame frequency is equal to or lower than 30 Hz.