Data communication apparatus
AssigneeCanon Kabushiki Kaisha
InventorsTakehiro Yoshida, Susumu Matsuzaki
Life of this patent
Estimating the term…
Abstract
A data communication apparatus having an error retransmission mode allows the operator to ascertain an amount of error data when an error is contained in data and when the error is not corrected despite retransmission of the error a predetermined number of times, or makes it possible to reproduce data with respect to correctly received data by discriminating correct data contained in error data, thereby preventing error data from becoming wasted as practically as possible. In addition, at the time of error retransmission, a transmission mode for retransmitting the error data is changed so as to minimize the number of incidents of error retransmission, thereby to enable efficient data transmission.
Claims26
A data communication apparatus comprising:
- receiving means for receiving data;
- recording means for recording data received by said receiving means;
- and
- control means for detecting error data in data received by said receiving means and, responsive to detection of the presence of error data, for controlling recording of information indicating that the received data contains error data.
A data communication apparatus comprising:
- data communication means for effecting data communication;
- detecting means for determining the presence of any error in data and detecting an amount of error data;
- and
- display means for displaying information which indicates an amount of error data detected by said detecting means, wherein said display means displays a specific pattern corresponding to said information.
A data communication apparatus comprising:
- transmitting means for transmitting data;
- receiving means for receiving a signal representing a request for retransmission of data;
- and
- control means connected to said transmitting and receiving means for determining an amount of error data among data transmitted by said transmitting means on the basis of said retransmission request signal and for causing transmission of information indicating said amount of error data.
A data communication apparatus comprising:
- receiving means for receiving data;
- means for determining an error in received data and for transmitting a signal representing a request for retransmitting a signal representing a request for retransmission of data which is determined to be in error to a data transmission side;
- and
- reproducing means connected to said receiving means for reproducing normal data contained in error data received by said receiving means when there is error data in said received data.
A data communication apparatus connectable to a modem for transmitting data through the modem which transmits data after transmitting a signal for adjusting the modem, comprising:
- receiving means for receiving a retransmission request signal;
- and
- control means for changing a time duration of transmission of said signal for adjusting the modem according to said retransmission request signal during retransmission.
A data communication apparatus comprising:
- transmission means for transmitting block data consisting of a plurality of frames;
- receiving means for receiving a retransmission request signal containing information indicating a frame to be transmitted in the transmitted block data;
- and
- control means for retransmitting frame data by said transmitting means according to said retransmission request signal, for analyzing information of said retransmission request signal and for changing a mode for transmission of data in accordance with the results of analysis.
A data communication apparatus comprising:
- data transmitting means for transmitting data by dividing the same into a plurality of blocks and effecting retransmission of block data in response to a retransmission request from a reception side;
- control means for shifting from transmission of a current block to transmission of an ensuing block when an error in said current block is not corrected even after retransmission is effected a predetermined number of times;
- and
- instructing means for prohibiting a shift by said control means to transmission of said ensuing block.
A data communication apparatus comprising:
- receiving means for receiving data in units of a page;
- detecting means for detecting an error in received data;
- reproducing means for reproducing said received data in units of a page;
- inhibiting means for inhibiting reproduction of page data when error data is contained in the data of a received page;
- and
- means for making a request for retransmission of error data in accordance with detection by said detecting means, wherein, when an error is detected by said detecting means despite retransmission of error data by a predetermined number of times in response to said retransmission request, said inhibiting means inhibits reproduction of page data contained in said error data.
A data communication apparatus which transmits data at a first transmission speed and transmits a signal for procedure of transmission at a second speed lower than said first transmission speed, comprising:
- first transmitting means for transmitting data at said first transmission speed;
- receiving means for receiving a retransmission request signal of data transmitted by said first transmitting means;
- retransmitting means for retransmitting data by said first transmitting means according to said retransmission request signal;
- counting means for counting a frequency of retransmission by said retransmitting means;
- second transmitting means for transmitting a signal indicating whether to repeat retransmission or to transmit next data when a retransmission request signal is received after retransmission a predetermined number of times;
- and
- transmitting means for transmitting a timing information for transmitting signal by said second transmitting means beforehand.
Dependencies are inferred from the claim text.