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US 4,829,524 AGranted
Data communication apparatus
AssigneeCanon Kabushiki Kaisha
InventorTakehiro Yoshida
Life of this patent
Estimating the term…
Abstract
There is a data communication apparatus having a transmitting section to divide data into a plurality of units and transmit the data and a memory section to store the data. This apparatus reads out the data of the designated unit from the memory section in response to a retransmission request signal from the reception side and a signal indicative of the designated unit and then retransmits the readout data from the transmitting section. Thus, even if the transmission error occurs the data can be retransmitted from the corresponding line and the retransmission is efficiently executed.
Claims29
A data reception apparatus comprising:
- receiving means for receiving data divided into a plurality of units;
- discriminating means for discriminating a reception error in reception of data by said receiving means;
- transmitting means for sending a retransmission request signal to a transmission side in response to a discrimination output of said discriminating means;
- and
- setting means for variably setting a discrimination reference of said discriminating means.
2 more elements
A data communication system comprising:
- a data transmission apparatus having transmitting means for sending data and a training signal prior to transmission of said data;
- a data reception apparatus having receiving means for receiving said data and said training signal;
- detecting means for detecting that said training signal was not correctly received by said receiving means;
- and
- discriminating means for discriminating due to which cause on the transmission side or on the reception side the reception error of said training signal occurred in response to said detection output.
2 more elements
A data transmission apparatus comprising:
- transmitting means for transmitting a communication procedure signal and a data signal;
- retransmitting means for resending the data signal when a retransmission request signal is sent from a reception side;
- confirming means for checking the presence or absence of the retransmission request signal after completion of transmission of the data signal;
- and
- control means for allowing the communication procedure signal to be sent after absence of the retransmission request signal has been confirmed by said confirming means.
2 more elements
Data reception apparatus cpmprising:
- receiving means for receiving data divided into line units;
- detection means for detecting an error in the line data received by said receiving means;
- and
- instruction means responsive to detection output of said detection means for instructing a transmitting end to retransmit the line data,
- wherein said instruction means issues the retransmission instruction when said detection means detects error over successive plural lines.
2 more elements
A data communication system comprising:
- data transmission apparatus having transmitting means for sending image data divided into lines and memory means for storing the data transmitted by said transmitting means;
- and
- data reception apparatus having receiving means for receiving a line of image data, detection means for detecting an error in the received line data and instruction means responsive to output from said detection means for instructing said data transmission apparatus to restransmit the line data,
- wherein said data transmission apparatus further comprises retransmission means for retransmitting the line data stored in said memory means in response to a retransmission instruction from said data reception apparatus, and wherein said instruction means issues the retransmission instruction to said data transmission apparatus when said detection means detects error over a predetermined number of lines and wherein the data of a line where said error occurred is not retransmitted if the number of lines on which said error is detected by said detection means is less than said predetermined number.
1 more element
Data reception apparatus comprising:
- receiving means for receiving data divided into a plurality of units;
- detecting means for detecting an error in each unit of the data received by said receiving means;
- and
- instruction means responsive to a detection by said detecting means, for issuing a retransmission instruction for instructing a transmitting end to retransmit a unit of data in which an error is detected,
- wherein said instruction means issues the retransmission instruction when said detection means detects error over successive plural units.
2 more elements
Data transmission apparatus comprising:
- transmitting means for transmitting data;
- identifacation means for identifying the function of a receiving end in response to a signal from the receiving end;
- retransmitting means responsive to a retransmission request for retransmitting data which the receiving end has failed to receive;
- manual designation means for designating a retransmission mode in said retransmitting means;
- and
- selecting means responsive to designation by said manual designation means and a result of identification by said identification means for selecting whether said retransmitting means is made operative or inoperative.
3 more elements
Dependencies are inferred from the claim text.