JPH0930067A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use an inexpensive CPU by curtailing the duties of CPU by constituting a control circuit for processing printing data and a control circuit including CPU which moves a print head relatively to a printing medium independent of each other. SOLUTION: The first control circuit 30 is composed of a so-called microcomputer having CPU and controls the line scanning of a print head and the transfer of a printing medium. The second control circuit 40 is composed of a hardware logic circuit and equipped with a receiving circuit 41 for receiving data from a superior device, a judgment circuit 42 for judging data to be printing data or control data, a writing circuit 44 for writing the printing data into a pattern receiving means, and a reading circuit 46 for reading from the receiving means. Data from a superior device are written into an image buffer area irrespective of CPU, and by a printing command from a superior device, the scanning of a print head is started under the control by CPU for printing. A printing medium is inserted, carried, and discharged by printing medium control commands from a superior device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus which receives print data from a host apparatus and prints the print data with, for example, an ink jet head.

[0002]

2. Description of the Related Art Conventionally, a printing device receives a character code to be printed from a host device such as a personal computer, develops it into a print pattern, and further performs pattern conversion or the like instructed by the host device. , I was printing on the desired paper surface. In recent years, the performance of host devices has improved,
WYSWYG (What You Se that makes it possible to print on the paper as it is displayed on the display device connected to the upper device
e What You Get) system was proposed,
In a printing device, which is an output device, this is realized by printing the printing pattern of the higher-level device as it is, and the printing device often does not perform any conversion of the printing pattern.

As advantages of this system, (1) the user can obtain almost the same print result as that displayed on the screen, and (2) the printing apparatus has a CG (character generator) corresponding to the character code. There is no need to provide the device at low cost. (3) The powerful CPU and vast memory of the host device can be used for pattern editing and the like.

[0004]

On the other hand, a problem with this system is that the amount of data that must be transferred from the host device to the printing device increases, and the processing speed of the data transferred from the host device of the printing device improves. I have to do it. In response to this, the printing apparatus has to use a faster CPU (central processing unit) in order to improve the data processing capacity, which is contrary to the advantage (2). Further, in recent years, high resolution printing has been performed by an ink jet type printing apparatus, and it has become necessary to use an even faster CPU.

As a measure against this problem, Japanese Patent Laid-Open No. 2-293
As disclosed in Japanese Patent No. 75, there is also one in which a low-cost CPU can be used by implementing a certain processing part by a hardware logic circuit instead of the CPU. However, even with this method, control commands etc.
Must be processed, and in the end, the CPU was forced to use one having a relatively high processing capacity.

An object of the present invention is to reduce the work of one control circuit by independently configuring the control circuit for processing print data and the control circuit for moving the printing mechanism relative to the print medium. However, it is to provide a cheaper printing device by making it possible to use a cheaper circuit.

[0007]

In order to achieve this object, a printing apparatus according to a first aspect of the present invention comprises a receiving circuit for receiving data from a higher-level apparatus, a pattern storing means for storing a print pattern to be printed, A printing mechanism for performing a printing operation on a printing medium based on the printing pattern stored in the pattern storing means; a moving mechanism for relatively moving the printing mechanism and the printing medium; and a first control circuit for controlling the moving mechanism. , A second control circuit including the receiving circuit and a writing circuit for writing print data in the receiving data of the receiving circuit into the pattern storing means.

With the above structure, the receiving circuit of the second control circuit receives the data from the host device, and the print circuit of the data is written in the pattern storing means by the writing circuit.
In addition, the first control circuit controls the relative movement of the printing mechanism and the printing medium, and one control circuit performs all processing of the printing apparatus.
Eliminates the need to control the operation, and makes the control circuit simple or has a small processing capacity.

According to a second aspect of the present invention, in the first aspect, the second control circuit sequentially reads out the patterns stored in the pattern storage means and transfers them to the printing mechanism as drive data. Is further included. As a result, the second control circuit further sequentially reads the patterns from the pattern storage means and transfers the patterns to the printing mechanism,
The load on the first control circuit is further reduced.

According to a third aspect of the present invention, in the printing apparatus according to any one of the first to second aspects, the second control circuit controls the data received from the higher-level device as the print data or the movement mechanism control. It is configured to further include a determination circuit that determines whether the data is data, transfers the print data to the write circuit, and transfers the control data to the first control circuit. As a result, the second control circuit also determines the data, so that the load on the first control circuit is further reduced and the processing is simple or has a small processing capacity.

According to a fourth aspect of the present invention, in the printing apparatus according to any one of the first to third aspects, the second control circuit includes a hardware logic circuit. This allows
A circuit that processes jobs such as writing or reading of print data and determination is made to have a simple circuit configuration.

According to a fifth aspect of the present invention, in the printing apparatus according to any one of the first to fourth aspects, the first control circuit stores a read-only memory for storing a program for controlling the moving mechanism and control data. And a central processing unit for calculating control data. As a result, a so-called microcomputer is used in the first control circuit to control the relative movement of the printing mechanism and the printing medium in various ways, while the microcomputer is mainly used only for the control and the processing capacity is reduced.

According to a sixth aspect of the present invention, in the printing apparatus according to any one of the first to fifth aspects, the type of data received from the higher-level device is transferred in the same format as that stored in the pattern storage means. Data, print commands,
It is composed only of control commands for the moving mechanism. This simplifies the control from the host device.

According to a seventh aspect of the present invention, in the printing apparatus according to any one of the first to fifth aspects, the second control circuit monitors the amount of the print pattern stored in the pattern storage section by the writing circuit, The configuration further includes a monitoring circuit which notifies the first control circuit when a predetermined amount is reached. As a result, the printing operation is started by the notification from the monitoring circuit, and the control from the host device is further simplified.

Further, in a printing apparatus according to an eighth aspect of the present invention, in the printing apparatus according to any one of the first to seventh aspects, the printing mechanism includes an ink jet head that ejects ink droplets toward a printing medium. As a result, the control circuit is configured with a simple one as described above or an inexpensive one with a small processing capacity, and an ink jet type high resolution printing apparatus is realized at a low cost.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a schematic mechanical structure of the printing apparatus. The printing mechanism, that is, the print head 20, is mounted on a carriage 21, and is moved by a moving mechanism along a printing medium, for example, a printing paper 23 in a row direction X and a direction Y perpendicular thereto. The moving mechanism includes a scanning mechanism 22 that reciprocally scans the carriage 21 in the row direction X, and a conveyance mechanism 24 that conveys the print paper in the direction Y perpendicular to the row direction.

The scanning mechanism 22 includes guide rails 25, 25 for slidably supporting the carriage 21 in parallel with the printing paper.
And a drive source for reciprocally scanning the carriage 21 in the same direction via a belt 26, for example, a CR motor 27 (FIG. 1). The transport mechanism 24 includes a roller 28 that is rotated around an axis parallel to the printing paper, and a drive source that drives the roller 28, such as an LF motor 29 (FIG. 1). The scanning mechanism 22 and the transport mechanism 24 may scan or transport either the print head 20 or the print paper 23.

The print head 20 has a large number of print elements at equal intervals in a direction substantially perpendicular to the row direction X, that is, in the vertical direction. As the print head 20, for example, an inkjet head can be used. In that case, the printing element is a nozzle for ejecting ink towards the printing medium. other than this,
As the print head, a dot impact type head having a striking wire as a print element, a thermal type head having a heating element as a print element, or the like that prints in a dot matrix format can be used.

FIG. 1 is a block diagram showing an electrical configuration for printing control, which generally includes the CR motor and LF.
A first control circuit 30 for controlling the motor and a second control circuit 4 for receiving data from a host device such as a personal computer and processing print data of the data.
It consists of 0 and.

The first control circuit 30 comprises a so-called microcomputer, and is a read-only memory RO for storing a program for controlling the scanning mechanism and the transport mechanism.
M, a writable and readable memory RAM for storing control data, and a central processing unit CPU for calculating control data
With. The control circuit inputs a signal from a key switch or the like of the operation panel 31, and outputs a drive signal to the CR motor 27 and the LF motor 29 of the scanning mechanism and the transport mechanism through the drive circuits 32 and 33, respectively.

The second control circuit 40 comprises a so-called gate array composed of hardware logic circuits,
A receiving circuit 41 for receiving data from the host device through the interface circuit I / F, a data discriminating circuit 4
2. A discrimination table 43, a writing circuit 44, and a reading circuit 46 are provided. The determination circuit 42 determines whether the received data is print data or control data for the scanning mechanism and the transport mechanism by referring to the data in the table 43, and outputs the control data to the first control circuit 30 in the case of control data. To do. The first control circuit 30 drives the scanning mechanism and the transport mechanism based on this data. Write circuit 4 for print data
4 is output. The write circuit 44 includes an address counter, and prints data, that is, bit map data following a code indicating an image pattern, in a pattern storage means, that is, a writable / readable memory (RAM) based on a strobe signal from a higher-level device. Write to the image buffer area 50.

After the transfer of the print data for a predetermined amount, for example, one line, the host device transfers the print command, that is, the control data indicating the size of the print area. As a result, the first control circuit 30 starts driving the CR motor 27 of the scanning mechanism based on the size of the printing area and transfers the timing signal to the reading circuit 46. The read circuit 46 reads a print pattern string corresponding to the print element array of the print head from the image buffer area 50 based on the timing signal, and drives the print head 20 through the drive circuit 34. When the printing of one line is completed, the host device transfers the control data for carrying the printing paper.

It is well known to those skilled in the art that each circuit in the second control circuit 40 can be composed of a counter circuit, a flip-flop circuit, a logic circuit and the like. It is advantageous to use the CPU of the first control circuit for the control of the LF motor, which has various conveyance amounts of the printing paper.

The table is a list of data from the host device in this printing apparatus.

[0026]

[Table 1]

In the table, control codes Z and G indicate print data, P indicates a print command, and F, L and X indicate paper control commands.
The printing apparatus can perform a printing operation with such data.

The operation of the printing apparatus will be described below with reference to the printing operation of one printing sheet.

1. When the user instructs “print” in the host device, the host device creates pattern data of a print image for one page.

2. The upper device transfers the printing paper insertion command (L) to the printing device. The printing device discriminates the printing paper insertion command by the discrimination circuit 42, and under the control of the first control circuit 30, the printing paper insertion operation, that is, the new printing paper is conveyed by the conveying mechanism 24 to a position facing the printing head.

3. The host device transfers as many raster images as the number of printing elements of the printing device. At that time, when the determination unit 42 receives the raster image control code (G) command, the writing circuit 44 secures a data area for one raster in the image buffer area 50,
Ready to receive. After that, the images for one raster are collectively transferred. This is repeated until the transfer of the raster image for one line is completed. The control code (Z) indicates that the data of one raster is all zero.

4. When the transfer of the raster image for one line is completed, the upper device transfers the print command, that is, the data (P) of the print area. The first control circuit of the printing apparatus drives the CR motor to scan the print head by the width corresponding to the received print area, outputs the print timing signal to the read circuit 46 in the print area, and outputs the print timing signal from the image buffer. The print pattern is sequentially read and the print head is driven to perform printing. When the printing of one line is completed, the second control circuit causes the reception circuit 41 to notify the upper device of the completion of printing.

5. The upper-level device transfers a control command (F) that conveys the printing paper by the amount corresponding to the printed area. When the printing apparatus receives the transportation command, the first control circuit drives the LF motor by the instructed transportation amount to transport the printing paper.

6. Repeat steps 3 to 5 until the printing of one page is completed.

7. Upon completion of printing one page, the upper-level device transfers the print paper discharge command (X). When the printing apparatus receives the discharge command, the first control circuit outputs L
The F motor is driven to eject the printing paper.

In this operation, the CP of the first control circuit
U controls only the motor, and data processing for printing is performed by the second control circuit, that is, the hardware logic circuit. As a result, the work load of the CPU can be reduced and an inexpensive CPU can be used. Also, the second control circuit only needs to support the three functions of receiving data from the interface, writing to the image buffer, and reading, and there is no one that performs complicated processing, and the control on the printer side is simplified. Since the simple structure can be adopted, the printing apparatus can be provided at low cost.

FIG. 3 shows another embodiment of the present invention. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the second control circuit 40 includes a monitor circuit 45 for counting the number of data written by the write circuit 44 in the image buffer area 50, and a CR.
A CR motor control circuit 47 for controlling acceleration, constant speed, and deceleration of the motor 27 is further provided. The monitoring circuit 45 notifies the first control circuit 30 when the number of counted data reaches a predetermined number, for example, for one row, and the first control circuit 30 sends a timing signal to start the printing operation based on the notification. To do. In accordance with the timing signal, the CR motor control circuit 47 starts driving the CR motor 27 and
When the R motor 27 reaches the constant speed range, the reading circuit 46
Reads data from the image buffer area, transfers the data to the print head 20, and starts printing.

When the length of the print area, that is, the scan range of the print head is always constant, as in this embodiment, C
The R motor control circuit 47 can be easily configured by a hardware logic circuit in the second control circuit 40. Also in the above-described embodiment, it is easy to provide the CR motor control circuit 47 in the second control circuit. It is also possible to start printing when the print data for one page is completed instead of when the print data for one line is completed as in the above-described embodiments.

In both embodiments, not only the host-based printing device that receives only image data as print data from the host device, but also the intelligent printing device uses the second control circuit in the simple part of the control code. By directly changing the flag area or the like of the CPU, it is possible to shorten the processing time of received data.

[0041]

As is apparent from the above description, the printing apparatus according to the first aspect of the invention receives the data from the host apparatus in the receiving circuit of the second control circuit, and writes the print data among the data. By writing the pattern in the pattern storage means by the circuit and controlling the relative movement of the printing mechanism and the printing medium by the first control circuit, it is not necessary to control all the processes and operations of the printing apparatus by one control circuit. The circuit can be simple or have a small processing capacity, and the printer can be manufactured at low cost.

According to the printing apparatus of the second aspect, in addition to the effects of the first aspect, the second control circuit further sequentially reads the patterns from the pattern storage means and transfers the patterns to the printing mechanism, whereby the first control circuit is obtained. The load on the printer can be further reduced and the printer can be manufactured at low cost.

According to the printing apparatus of the third aspect, in addition to the effects of the first aspect, the second control circuit determines whether the print data or the control data for the moving mechanism. The load on the first control circuit is further reduced, and the first control circuit is made simple or has a small processing capacity.

According to a fourth aspect of the present invention, in addition to the effects of any one of the first to third aspects, the second control circuit is configured by a hardware logic circuit.
A circuit for processing work such as writing or reading of print data, discrimination, and the like can have a simple circuit configuration, and a printing device can be manufactured at low cost.

According to the printing apparatus of the fifth aspect, in addition to the effect of any of the first to fourth aspects, the first control circuit is a so-called microcomputer, so that the relative movement of the printing mechanism and the printing medium can be varied. By controlling the print data by the second control circuit as described above, the microcomputer can be mainly used only for the control, and the processing power of the microcomputer can be reduced. be able to. That is, the printing apparatus can be manufactured at an extremely low cost.

According to the printing apparatus of the sixth aspect, in addition to the effects of any of the first to fifth aspects, the types of data received from the position apparatus are only image data, a print command, and a control command of the moving mechanism. Therefore, the control from the host device can be greatly simplified.

In addition to the effect of any one of claims 1 to 5, the printing apparatus according to claim 7 starts printing by the notification from the monitoring circuit of the second control circuit, thereby controlling from the host device. Can be further simplified.

Further, according to the printing apparatus of the eighth aspect, in addition to the effect of any one of the first to seventh aspects, the control circuit is simple or inexpensive and has a small processing capacity as described above. It is possible to provide an inkjet high-resolution printing apparatus at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration for controlling a printing apparatus.

FIG. 2 is a perspective view showing a schematic mechanical configuration of the printing apparatus.

FIG. 3 is a block diagram showing an electrical configuration of another embodiment.

[Description of Reference Signs] 20 print head 30 first control circuit 40 second control circuit 41 reception circuit 42 determination circuit 44 writing circuit 46 reading circuit 50 pattern storage means

Claims (8)

[Claims] 1. A receiving circuit for receiving data from a host device, a pattern storing means for storing a print pattern to be printed, and a printing operation for printing on a print medium based on the print pattern stored in the pattern storing means. Mechanism, a moving mechanism that relatively moves the printing mechanism and the printing medium, a first control circuit that controls the moving mechanism, print data of the receiving circuit and the received data of the receiving circuit in the pattern storage unit. And a second control circuit including a writing circuit for writing. 2. The second control circuit according to claim 1, further comprising a read circuit that sequentially reads the patterns stored in the pattern storage unit and transfers the patterns to the printing mechanism as drive data. Printing device. 3. The printing apparatus according to claim 1, wherein the second control circuit determines whether the received data from the host device is the print data or the control data of the moving mechanism, and prints the print data. The printing apparatus further includes a determination circuit that transfers data to the writing circuit and transfers the control data to the first control circuit. 4. The printing apparatus according to claim 1, wherein the second control circuit is composed of a hardware logic circuit. 5. The read control memory according to claim 1, wherein the first control circuit stores a program that controls the moving mechanism, and a writable and readable memory that stores control data. A printing apparatus comprising a central processing unit for calculating control data. 6. The image data according to claim 1, wherein the type of data received from the host device is stored in the pattern storage means and transferred in the same format, a print command, and the movement. A printing apparatus comprising only control commands for the mechanism. 7. The second control circuit according to claim 1, wherein the second control circuit monitors the amount of the print pattern stored in the pattern storage unit by the writing circuit, and when the predetermined amount is reached, the second control circuit is activated. The printing apparatus further includes a monitoring circuit for notifying the first control circuit. 8. The printing apparatus according to claim 1, wherein the printing mechanism is an inkjet head that ejects ink droplets toward a printing medium.