Abstract: A host computer logs in an image providing device such as a scanner connected by a serial bus, and reverses flow control of data transfer by issuing a Reverse command. The image providing device opens a transfer channel by an OpenChannel command, transfers image data in form of blocks. When the transfer of the image data has been completed, the image providing device closes the transfer channel by a CloseChannel command, and reverses the flow control of the data transfer again by the Reverse command. This changes the data transfer direction of a device having a bi-directional data transfer function, i.e., a device having a data reception function and a data providing function.

Abstract: A data transmission system where an image providing device and a printer are directly connected by a 1394 serial bus, a command is sent from the image providing device to the printer, then a response to the command is returned from the printer to the image providing device. Image data is sent from the image providing device to the printer based on information included in the response. The printer converts the image data outputted from the image providing device into print data. Thus, printing can be performed without a host computer by directly connecting the image providing device and the printer by the 1394 serial bus or the like.

Abstract: For providing a communication system capable of easily and efficiently confirming information present in another device and easily and efficiently selecting desired information from such information, a digital camera informs a printer of format information of an image file (including a photographed image, a thumbnail image formed by reducing the photographed image) held in an internal memory of the digital camera, so that the printer can directly fetch the thumbnail image only from the image file held in the internal memory of the digital camera, for example by the pull-type data transfer method.

Abstract: Disclosed is an information processing apparatus connected to a printer through an interface such as IEEE1394 capable of changing a transmission bandwidth. In order to perform a transmission at an optimum transmission speed when image data is transmitted by an isochronous transmission, the apparatus comprises means for recognizing a printer performance and bandwidth setting means for setting the transmission bandwidth in accordance with the recognized performance, wherein the transmission bandwidth is set so that it may be suitable for the printer performance, whereby the data can be transmitted.

Abstract: An information processing apparatus comprises: a memory to store emulation information which is designated from a host computer that is connected to a printer via a general parallel interface; a judging circuit to judge a delimiter of print data; and a control unit to switch the emulation on the basis of the emulation information stored in the memory and the result of the judgment by the judging circuit. When each section of the apparatus is in the inoperative state, they are set into the power saving mode and are sequentially controlled. Thus, the power saving of the whole apparatus can be realized.

Abstract: A system comprising devices connected via a 1394 serial bus solves a problem that if omission of data packet occurs in isochronous transfer capable of high-speed data transfer, only data without the omitted data packet is sent to a transfer destination. A recording/reproduction device 101 repeatedly sends image data stored in a storage medium by the isochronous transfer, and a printer 102 receives the image data repeatedly sent by the isochronous transfer. If a data packet has been omitted in the received data, the omitted data packet is obtained from the data repeatedly sent by the isochronous transfer, thus the printer 102 can print an image based on the complete image data.

Abstract: A recording apparatus capable of automatically re-writing recording data includes a recording head for recording images on a recording medium in accordance with recording data; a memory for storing recording data to be supplied to the recording head; an address generating device which generates, with respect to the memory, addresses synchronized with recording performed by the recording head and which reads out the recording data stored in the memory; and a data writing device for writing predetermined data in the memory on the basis of the addresses which have been generated by the address generating device and from which the recording data has been read.

Abstract: In an information processing apparatus with a main control unit and a printer, a transfer unit transfers commands and data between the main control unit and the printer, a memory temporarily stores the data transferred to the printer, and a detector detects the remaining capacity of the memory. The information on remaining capacity of the memory is supplied to the main control unit to improve the execution efficiency of the main control unit.

Abstract: An information processing apparatus includes an information processing unit power saving controller for controlling a power saving function of an information control unit for controlling various devices, and a printer unit power saving controller for controlling a power saving function of a printer unit for performing a print operation. The printer unit power saving controller controls the power saving function of the printer unit on the basis of a predetermined command from the information processing unit power saving controller.

Abstract: A printing method and apparatus according to the present invention is capable of instructing whether or not a printing portion is used in a case where data is received from a host so as to be printed, and the initializing control required to perform printing can be skipped at the time of power supply if the printing portion is not used, or arranged to store a fact whether or not initialization has been performed so that whether or not the initialization is performed is controlled at the time of the power supply or when a printing opportunity has been issued.

Abstract: In a data transfer method, virtual handshake busy data is transferred to an I/O register when data is transferred through a parallel interface between data processing and printer units connected to the I/O register through a bus and a transfer storage area in the printer unit has an empty area having a predetermined amount or more.

Abstract: A method and apparatus for processing data, with the data processing side performing main control and the print control side including control for saving power. The print control side performs transition of a plurality of power saving states to obtain an optimal power saving state on the basis of transfer of data from the main control side, and the data processing side performs various control operations independently of the transition of the plurality of power saving states.

Abstract: A control apparatus of a printer causes a recording head to form an image by a dot matrix while scanning the recording head in a predetermined direction relative to a recording medium. The control apparatus includes a transfer unit for transferring recording data stored in a memory to the recording head, a drive control unit for driving and controlling scanning of the recording head, and a synchronizing unit for synchronously driving the transfer unit and the drive control unit.

Abstract: A printer controller is for controlling a serial dot printer. The printer prints a dot picture on a paper by reciprocally scanning a recording head in horizontal forward and backward directions. The printer controller includes a buffer memory for storing print data in a dot pattern, a print starting address register for transferring the print data from the buffer memory to the recording head, a print end address register, an address counter, a print timing register for drive controlling the recording head, and a print timing pulse generator. The printer controller corrects vertical misregistration of print in the forward and backward printing by adjusting a set value of the print starting address of the print starting address register or a set value of the print timing register.

Abstract: There is provided an apparatus for driving an electroluminescence (EL) panel which is arranged on the back side of the display surface of an LCD and used as a back light thereof.