JPS59200338A - Printer - Google Patents

Abstract

PURPOSE:To improve the operability of a printer by providing a means which discriminates a designated transmission format based on the transmission format designation data transferred from the side of a host system and a means which sets a transmission format in response to the result of said format discriminating means. CONSTITUTION:A host system A and a printer control circuit B which controls each part of a printer transfer data to each other via a printer interface circuit C. The circuit C is provided with a serial/parallel interface, i.e., a programmable communication interface which can set a transmission format, etc. from outside, etc. A designated transmission format discriminating means D discriminates the designated transmission format based on the transmission format designation data transferred from the system A. Based on the result of this discrimination, the transmission format is set to a designated one.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printer that transmits and receives data to and from a host system via a serial interface.

For example, R8232 is used in various printers such as inkjet printers, dot printers, and thermal printers that are connected to host systems such as personal computers, office computers, and word processors.
Some devices are designed to send and receive data to and from a host system via a serial interface that complies with the C standard.

By the way, for example, the transmission format of the word processor itself may differ depending on the individual word processor, and in order to provide versatility to the printer, it is necessary to be able to change the transmission format on the printer side depending on the word processor.

Therefore, conventionally, a switch for specifying the transmission format of the serial interface was provided on the printer side, and by operating this switch, the operator could set the transmission format on the printer side according to the transmission format 1 on the host system side. .

However, providing a switch for specifying the transmission format in this way increases the number of parts on the printer side, and requires operating the switch each time a different host system is used for the transmission format 1. , it has the disadvantage of poor operability.

Purpose This invention has been made in view of the above points, and an object thereof is to improve the operability of the printer as described above without increasing the number of parts.

1 Nico sentence Hereinafter, the configuration of the present invention will be explained based on one embodiment.

FIG. 1 is a block diagram showing a basic embodiment of the invention.

In the figure, a host system A and a printer control circuit B that controls each part of the printer exchange data via a printer interface circuit C.

The printer interface circuit C includes a serial/parallel interface, which is a programmable communication interface, which allows transmission formats and the like to be set from the outside.

The designated transmission format determination means is host system A.
The designated transmission format is determined based on the transmission format designation data transferred from the printer interface circuit C through the printer interface circuit C.

The transmission format setting means E sets the transmission format of the printer interface circuit C to the specified transmission format based on the determination result of the determination means.

In this way, the transmission format on the printer side can be set and changed from the host system side.

2 and 6 are a perspective view showing the appearance of a dot impact printer embodying the present invention, and an exploded perspective view of the outer casing thereof.

In both figures, the outer casing of this printer is composed of a main body case 1 that houses a printing mechanism section and a printing control section, a cover 2, and a bottom plate 6.

FIG. 4 is a plan view showing the printing mechanism section of this printer.

In the figure, a platen 11 for wrapping and feeding paper to be printed is rotatably attached to a frame 10.

This platen 11 is driven via a gear train 13 by a paper feed motor (line feed motor) 12 consisting of a stepping motor fixed to the frame 1o, and automatically feeds the paper.

Further, the platen 11 has knobs 14 and 15 fixed to both ends, and can be manually rotated by turning the knobs 14 and 15 when loading or removing paper.

Note that rotatable rollers 1G and 17 are brought into pressure contact with this platen 11 in order to press the paper against the surface.

A carriage 21 is mounted on a rond 18 and a stay 19 fixed to the frame 10 so as to be movable parallel to the platen 11 in its axial direction.

The carriage 21 includes a print head 23 on a carrier frame 22, a solenoid 24 for driving the print head 23, ribbon masks 25 and 26, and the like.

This carriage 21 is operated by a space motor 28 consisting of a four-phase stepping motor mounted on the frame 10, and a timing roller 29 fixed to its rotating shaft 28a and a roller (not shown) for rotating the reel of the ribbon case 30 mounted on the frame 10. and roller 31. :52 and is driven via a timing belt 6 fixed to the lower part of the carriage 21.

The ink ribbon 34 wound around the reels 30a and 30b of the ribbon case 30 is held between the ribbon mask 2 of the carriage 21 and the four hooks 35 to 68 attached to the frame 10.
5 and 26, and is positioned between the platen 11 and the print head 2B, and is configured to run when the space motor 28 moves the carriage 21 forward and backward by a running direction switching mechanism (not shown). ing.

FIG. 5 is a block diagram showing an example of a control section of this printer.

In the figure, a printer control circuit 41 is a circuit that controls the entire printer, serving as a determining means and a setting means, and includes a CPU (central processing unit), a program memory (ROM), a data memory (RAM), and an input memory. It is composed of a microcomputer including an output device (Ilo) and the like.

This printer control circuit 41 receives print data, space data, line feed data, and carriage data from a host system such as a computer or a word processor via a printer interface circuit 42 consisting of a serial/parallel interface that is a programmable communication interface. return data.

Various data such as transmission format designation data are transferred.

Then, based on the processing results of various input data, the printer controller 1 to the roll circuit 51 first output a drive pulse DS to the driver circuit 44 based on the detection result of the position sensor 43 in order to designate the printing position. Then, the space motor 28 is driven and controlled, and the carriage 21 is positioned at a predetermined position.

Further, for printing, the printer controller 1 to the roll circuit 41 output a drive pulse DH to the driver circuit 45 to drive and control the solenoid 24, and selectively drive each print side of the print head 26. Since the details are well known, their explanation will be omitted.

Further, the printer control circuit 41 outputs a drive pulse DL to the driver circuit 46 to drive and control the line feed motor 12 in order to feed the platen 1.
Rotate 1.

The printer control circuit 41 also receives the rotation of the space motor 28, detection pulses from a home position detection sensor, and detection pulses from a cover open switch and a paper detection switch (not shown).

Further, this printer control circuit 41 sets the transmission format of the printer interface circuit 42 according to the designated data for the transmission format 1 transferred from the host system side or the designated result of the transmission format designation switch 47.

The details will be described later.

Next, details of the printer interface circuit 42 will be explained with reference to FIGS. 6 to 9.

FIG. 6 is a block diagram showing an example of a serial/parallel interface that constitutes the main part of this printer interface circuit 42.

In the figure, first of all, the basic configuration of this serial/parallel interface will be described. Data bus buffer 421 is a bidirectional 8-bit buffer, and parallel data D, -D? send and receive.

The read/write control logic section 422 has a control word register and a command word register, including a reset RESET, a clock CLK, a write data or control WR, a read data RD, and a control/data C/D.

Each signal of chip enable O8 is inputted to generate an internal control signal.

The modem control unit 423 inputs data set ready DSR and clear to send CTS signals from the modem, and outputs data terminal ready DTR and request 1 to send RTS signals to the modem; and controls the modem.

The transmission buffer 424 converts parallel data input from the data bus buffer 421 into serial data (P
-+S conversion) transmission data TxD is output.

The transmission control unit 425 inputs the transmitter clock TxC, controls the transmission buffer 424 based on the command from the read/write control logic unit 422, and outputs each signal of transmitter empty TxE and l to transmitter ready TxRDY. .

The reception buffer 426 converts the received data RxD from serial data to parallel data (s-+P conversion), checks the pin 1~ and characters according to the specified transmission format 1~, and transfers the assembled characters to the data bus buffer 421. Transfer to.

The reception control section 427 inputs the receiver clock RxC, controls the reception buffer 426 based on the command from the read/write control logic section 422, and outputs the receiver ready RxRDY.

This serial/parallel interface has a transmission format, or word length (character length).

The program can specify the number of steps, the presence or absence of a parity check, the polarity of parity, and the baud rate.

The asynchronous mode command format 1- of this interface is shown in FIG. 7, and the command command formats 1- are shown in FIG. 8, respectively. Further, the initial setting flow is shown in FIG. 9.

Next, the operation of the embodiment configured as described above will be explained in the 10th section.
The explanation will be made with reference to the figures and FIG. 11 as well.

First, with reference to FIG. 10, the relationship between transmission format designation data from the host system and transmission formats 1 to 1 will be described.

In this embodiment, the transmission format 1-specified data transferred from the host system side is expressed in hex as ``rl l x+'' and ``rl 2n'', as shown in FIG.

Three types of r24HJ are set. Note that FIG. 10 shows the received data Rx of the printer interface circuit 42.
It shows D.

The relationship between these transmission format 1-specified data and transmission format 1- is set as shown in the following table (but is not limited to this).

FIG. 11 is a flowchart showing an example of the transmission format 1 to setting operations executed by the printer control circuit 41.

In the figure, the printer control circuit 41 first sets the transmission format of the printer interface circuit 42 to a predetermined initial transmission format 1 according to the initial settings shown in FIG.

This initial transmission format must be set the same as on the host system side for Pauley 1-, but
Other settings can be set arbitrarily.

After completing this initial setting, when data is transferred from the host system side, it is determined whether the input data is "11■I" of the transmission format specification data, and if it is "rllH", the transmission format is mode ■. Set "11H
”, it is determined whether it is r1211J or not, and “12■I
”, set the transmission format of mote H, and set r1
If it is not 2IN, r 24 Determine whether it is HJ or not, r
24- If it is H or l, set the transmission format of mode (2), and if it is neither, wait for data input from the host system side again.

In this case, even if the initial transmission format does not match the host system's transmission format and errors such as parity errors and framing errors occur, these errors will be ignored and the above operation will be executed. .

In this way, by transferring the transmission format specification data from the host 1 system side to the printer side,
The transmission format on the printer side is set to be the same as the transmission format 1 on the host 1 to system side.

Therefore, it is not necessary to operate the transmission format designation switch 47 provided on the printer side every time the transmission format 1 to 1 on the host system side changes, and operability is improved.

In the above embodiment, a transmission format designation switch is provided on the printer side, but this switch may not be provided, and the number of parts on the printer side can be reduced by eliminating this switch.

Effects As explained above, according to the present invention, the operability for adjusting printer transmission formats 1 to 1 on the host system side is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a basic embodiment of the invention, FIGS. 2 and 3 are an external view of a printer embodying the invention, and a perspective view of its outer casing, and FIG. FIG. 5 is a block diagram showing an example of the control section; FIG. 6 is an example of the serial/parallel interface that constitutes the printer interface circuit of FIG. 5. FIG. 7 is an explanatory diagram showing an example of the mode command format; FIG. 8 is an explanatory diagram showing an example of command command formats 1 to 1; FIG. FIG. 10 is a flowchart for explaining the transmission format designation data, and FIG. 11 is a flowchart showing an example of the setting operation for the transmission format 1 executed by the printer controller 1 to roll circuit of FIG. 5. be. 21 Carriage 23° Print head 41... Printer control circuit 42... Printer interface circuit Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. In a printer that transmits and receives data to and from a host system via a serial interface, a designated transmission format determining means for determining a designated transmission format based on transmission format designation data transferred from the host system; 1. A printer comprising: transmission format setting means for setting a transmission format of the serial interface according to a determination result of the means.