JP2645170B2 - Line printer printing method - Google Patents

Description

The present invention relates to a printing method for a line printer.

2. Description of the Related Art There is known a line printer that uses a thermal line head as a dot type line head and prints characters, bar codes, figures, and the like on labels and tags.

In conventional line printers of this type, even when printing is performed with a width shorter than the width of the line head, the drawing memory draws print data corresponding to the length of the line head and draws the line head based on the print data. To print.

[Problems to be Solved by the Invention] However, even when printing is performed with a width shorter than the width of the line head as described above, if the print data corresponding to the length of the line head width is always drawn in the drawing memory, the line printing is performed. The required capacity of the drawing memory is no different from the case where printing is performed with the width of the line head, and there is a problem that the drawing memory cannot be used efficiently.

Therefore, the present invention stores only the data actually used for printing in the drawing memory, and outputs the stored data together with the separately generated printing dummy data to the line head. It is an object of the present invention to provide a line printer printing method which can reduce the capacity of a drawing memory required for line printing, and thus can use the memory efficiently.

[Means and Actions for Solving the Problems] The present invention relates to a line printer that draws print data in a drawing memory and then drives a dot line head based on the print data to perform printing. When printing with a short width, only the data to be actually printed is drawn in the drawing memory, and when the data to be printed is output to the line head, the non-printing data other than the data actually printed on the line head is used. It is to output dummy data continuously from data to be printed from dummy data generating means for generating dummy data.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a CPU (central processing unit) constituting a control unit main body, 2 denotes a ROM (read only memory) in which program data for the CPU 1 to control each unit is stored, 3 denotes a character ROM, 4 is a RAM (random access memory), 5 is a data buffer RAM constituting a drawing memory, and 6 is an asynchronous receiver / transmitter (hereinafter, UART) for controlling communication with a host device as a host device.
, 7 is a head driver for driving a thermal line head 8 as a dot-type line head, 9 is a motor driver for driving a paper feed motor 10 for controlling the feeding of a print medium, and 11 is a dot driver for printing the thermal line head 8. This is a timer circuit that creates the timing when the operation is performed.

CPU1 and each ROM2,3, each RAM4,5, UART6, each driver
7, 9 and the timer circuit 11 are connected via a bus line 12.

When the CPU 1 receives data from the host device via the UART 6, the CPU 1 analyzes the data to generate print data, expands the print data based on the character pattern of the character ROM 3, and draws the print data on the data buffer RAM 5. I have. The head driver 7 is controlled based on the data drawn in the data buffer RAM 5 to operate the thermal line head 8.

The head driver 7 is provided with a dummy data generating means shown in FIG. That is, the dummy data generating means includes a 1/16 divider 13, an A counter 14, a B counter 1
5, a C counter 16, an inverter 17, and two two-input AND gates 18 and 19. One word shown in FIG. 3A corresponds to 16-bit data, and FIG. The data transfer clock generated as shown in FIG.
At 13, the clock is converted into a 1/16 transfer clock as shown in FIG. The 1/16 transfer clock is supplied to the counters 14, 15, and 16 of A, B, and C, respectively.

Wherein the thermal line head 8 are input in two input mode is divided into data, for example, left and right 1 ₀ corresponding to the head width as shown in Figure 4. Then the A counter 14 left and right data length, ie l _0/2 transfer word number n ₁ the corresponding is set to, for the B counter 15 transfers a word number n ₂ corresponding to the white data l ₂ of the right The number of transfer words n ₃ corresponding to the actual data length to be actually printed on the left is set in the C counter 16.

Wherein A counter 14 is adapted to numeric n ₁ that is set down count advance in response to the falling of 1/16 transfer clock and outputs a transfer end signal becomes "0". High level when the B counter 15 1/16 in response to the falling edge of the transfer clock numeric n ₂ that is set in advance down counting is until "0" outputs a low level signal "0" It is designed to output a signal. The C counter
16 1/16 fall in response to become to a value n ₃ which is preset down counter becomes "0" outputs a low level signal "0" when the output a high-level signal of the transfer clock It is supposed to.

The output signal of the B counter 15 is
18 to one input terminal and the C counter
The 16 output signals are supplied to one input terminal of the AND gate 19 via the inverter 17. Right data is supplied to the other input terminal of the AND gate 18, and left data is supplied to the other input terminal of the AND gate 19.

In this embodiment having such a configuration, the portion of the actual printing data to the effective printing width l ₀ as shown in FIG. 4 in the case of performing printing width smaller than the effective printing width of the thermal line head 8 Since the width is narrow as shown by oblique lines in the figure, non-printing parts l ₂ and l ₃ are generated on the left and right sides, a low level signal is output for the right side data until the B counter 15 counts n _2. Therefore, a low level, that is, non-printing data “0” is output from the AND gate 18 to the thermal line head 8. This corresponds to the length of the portion l ₂ of the non-printed in the right data.

Then, the B counter 15 counts n ₂ and the numerical value is “0”
, A high-level signal is output. As a result, the actual printing data actually printed from the AND gate 18 is output to the thermal line head 8.

In addition, since a low-level signal is output for the left data until the C counter 15 counts n ₃ , a high-level signal is input to the AND gate 19 via the inverter 17. Therefore, the actual print data to be actually printed is output from the AND gate 19 to the thermal line head 8.

Then, the C counter 16 counts n ₃ and the numerical value is “0”
, A high-level signal is output. As a result, a low-level signal is input to the AND gate 19 via the inverter 17, so that the AND gate 19 outputs low-level, that is, non-printing data “0” to the thermal line head 8. And this state is performed many words corresponding to the length of the portion l ₁ of the non-printing in the left data.

As described above, the dummy data is output from the dummy data generating means for the non-printing portion of the thermal line head 8, and only the data to be actually printed is drawn in the data buffer RAM5. Data buffer RA when printing characters, barcodes, numbers, graphics, etc. on narrow labels.
The width of the data drawn on M5 may be the width printed on the label. That is, the data buffer required for line-direction printing
The amount of RAM5 can be reduced accordingly. Therefore, when label print data is stored in the data buffer RAM 5 having a fixed capacity, the capacity necessary for printing in the line direction can be reduced, and the label length that can be stored can be increased accordingly. That is, the memory can be used efficiently.

In the above-described embodiment, the data corresponding to the head width is divided into two on the left and right. However, the present invention is not limited to this, and the data may be divided into three or more. In this case, a counter may be provided for each divided data.

[Effects of the Invention] As described in detail above, according to the present invention, only data actually used for printing is stored in the drawing memory,
By outputting the stored data and the dummy data for non-printing separately generated to the line head, the capacity of the drawing memory required for line printing can be reduced, so that the memory can be used efficiently. A printing method of a line printer can be provided.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a block diagram, FIG. 2 is a circuit configuration diagram of a dummy data generating means, FIG.
FIG. 4 is a waveform diagram showing the timing of data and signals for explaining the operation of FIG. 2, and FIG. 4 is a diagram showing the relationship between the effective print width of the thermal line head and the actual print width. 1 ... CPU (central processing unit), 5 ... data buffer RAM, 7 ... head driver, 8 ... thermal line head, 11 ... timer circuit.

Claims (1)

(57) [Claims] In a line printer which draws print data in a drawing memory and drives a dot type line head based on the print data to perform printing, when printing is performed with a width shorter than the width of the line head, A dummy that generates only non-printing dummy data other than data actually printed on the line head when drawing only data to be actually printed on the drawing memory and outputting data to be printed to the line head. A printing method for a line printer, wherein the dummy data is output continuously from the data to be printed from a data generating means.