JPS59180787A - Printer - Google Patents

Abstract

PURPOSE:To increase the speed of data writing with one image buffer by reading out data already written in the image buffer by a prescribed unit and writing data of the prescribed unit in the memory of the read out address. CONSTITUTION:Printing data P1-Pn are constituted of a prescribed unit (for example, one line quantity) and already written in a memory 1. When a data request signal DR is generated from a printing section 2 and also a write instruction W is generated from a processor 3, a control section 4 generates control signals B and E. The control signals B and E slowly advances an address counter 9 by actuating a read control section 5, opening an AND gate 7, and passing through a clock CL1, designate an address A1, and send data P1 to the printing section 2. After delaying by T second by means of a delay circuit 10, another address counter 12 is slowly advanced by actuating a write control section 13, opening an AND gate 11, and passing through another clock CL2, data Q1 are written in the address A1.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a printer having a print buffer.

(b) Prior Art and Problems Laser beam printers have an image buffer that temporarily stores print data. One way to increase the speed of a printer is to provide two image buffers.This means that while the print data in one image buffer is being printed, the print data in the other image buffer is transferred to another device (such as a processing device). This is to reduce the transfer time by writing the print data from the printer. As is well known, the capacity of the image buffer is limited, so providing two image buffers increases the cost of the printer. On the other hand, if the data already written in the image buffer is read out in a predetermined unit, and then the predetermined unit of data is written immediately after being read, the number of image buffers is J? ! , moreover, the purpose of speeding up can be achieved.

(C) Object of the Invention The present invention has focused on the above points, and an object of the present invention is to provide a printer that improves printing speed.

(d) Structure of the Invention The present invention provides a printer having a buffer and a print section, including a first address selection means for selecting an address of the buffer, and an address selected by the first address selection means for a predetermined period of time. the first address selection means, comprising: second address selection means for selecting after the elapse of time; means for sequentially writing predetermined units of data into the buffer; and means for sequentially reading data in the buffer in predetermined units; After reading the data in the transfer buffer in predetermined units, the second address selection means is used to write data from another device in predetermined units to the address of the buffer from which the predetermined unit of data was read. This is a printer that is characterized by the ability to As described above, the present invention improves Q1 printing efficiency by reading data in one image buffer in predetermined units and writing new data to that address immediately after this reading. It was planned○(
e) Examples of the invention The present invention will be explained below with reference to the drawings. The drawing is a block diagram illustrating an embodiment of the present invention.

It is assumed that the print data P in the drawings is composed of a predetermined unit (for example, one line) of data P, -Pn, and similarly, the print data Q is also composed of data Q, -Qn. It is assumed that the print data P has already been written in the memory 1 in the drawing, and the print data in the memory 1 is read out (in the order of pt to Pn) and sent to the print section 2. and printing is performed. In the drawing, when the data request signal DR is issued from the print unit 2 and the write command W is also issued from the processor 3,
Upon receiving this, the control section 4 issues control signals B and E.

The control signal B activates the read control section 5, and the control signal E opens the AND gate 7, so that the clock pulse CL from the pulse generator 8, the address counter 9 is set to 1.
The address A of memory l is selected. Therefore, the data P1 at this address A is read out by the readout control section 5 and sent to the printing section 2. On the other hand, the control signal E passes through the delay circuit 10 (delay time: 1 second) and becomes the control signal E'3-! +, reaches AND gate 11. This opens the AND gate 11, but this time is T seconds later than the time when the AND gate 7 opens. Clock pulse CL from pulse generator 8! The address counter 12 increments, the address A of the memory 1 is selected, and the convolution control unit 13 activated by the control signal E' writes to this address A1 from the processor 3. Data Q
The first data Q, is newly written. This read/write control is similarly performed for addresses A2 to An of the memory 1. Therefore, writing of the predetermined unit data of data in one memory is smoothly performed with a one-step delay in reading the predetermined unit data.

(f) Effects of the Invention As described above, the present invention provides one image buffer memo V+.
By simply using the printer, data in the memory can be sent to the print section and new data can be written into the memory, thereby reducing the data transfer time. It has the advantage of improving efficiency 4-.

[Brief explanation of the drawing]

The drawing is a block diagram illustrating an embodiment of the present invention,
The symbols used in the figure are as follows: 01 is the memory, 2 is the print section, 3 is the processor, 4 is the control section, 5 is the readout control section, 6 is the print control section, 7 and 11 are AND gates, 8
9.12 is the address counter, 10
1 is a delay circuit, 13 is a readout control unit, and 14 is a print head. A2 is the address, B, E, E' are the control signals, CL,
. CL2. CL3 is a clock pulse, DR is a data request signal, P+ PIT P21 P”t Q+ Q+ is data, T is time, W is 0 indicating a write command

Claims (1)

[Claims] In a printer having a buffer and a print section,
a first address selection means for selecting an address of the buffer; a second address selection means for selecting the address selected by the first address selection means after a predetermined time has elapsed; writing means; and means for sequentially reading data in the buffer in predetermined units, and after the data in the buffer is read out in predetermined units by the first address selection means, the second address selection means A printer that writes data from another device in a predetermined unit to the address of the buffer from which the predetermined unit of data was read.