The present invention relates to a printer of the type in which printing is carried out in accordance with data fed from a host computer. More particularly, the invention relates to such a printer in which operation for halting the printing can easily be performed.
A conventional printer is provided with an input buffer of a relatively large capacity into which printing data fed from the host computer is temporarily stored. This makes it possible for the host computer to consecutively transmit a predetermined amount of data regardless of the printing operation. In addition, transmission latency can be reduced. With respect to the printer provided with the input buffer of a large capacity, the host computer is capable of executing another job after the input buffer has become full with the data being transmitted from the host computer. The host computer does need to wait until the printing operation is terminated. The host computer may again consecutively transmit another predetermined amount of data to the printer after the input buffer is exhausted. In this fashion, the operational efficiency of the host computer is enhanced with the use of the large capacity input buffer.
However, while it is advantageous in that the operational efficiency on part of the host computer is enhanced, an inconvenience is caused in the case where the printing operation is to be halted due to unsatisfactory printing format or an error or confusion of the documents to be printed. In such a case, an operator has to carry out two operations, one for halting the transmission of data from the host computer and another for clearing the input buffer of the printer. Moreover, it is necessary that the operation for halting the data transmission precede the operation for clearing the input buffer. If only the data transmission from the host computer is halted and the input buffer is not cleared, the data remained in the input buffer is subjected to printing in the subsequent printing. On the other hand, in the case where only the input buffer is cleared and the data transmission from the host computer is not halted, the residual data which remained untransmitted is transmitted from the host computer to the printer when the printing operation is restarted after the input buffer is cleared. Such residual data is transmitted until the input buffer is filled with the data and is subject to printing in the subsequent printing operation.
The input buffer is normally cleared by once switching off a power source and again switching on the power source. When this has done, the printing format is set to an intial condition, so that it is necessary for the host computer to once again set the printing format.
USPTO Backgrounds
USPTO Backgrounds