JPH0531973A - Image recording device - Google Patents

Abstract

PURPOSE:To provide an image recording device wherein output processing of printing data of an external device can be performed smoothly by utilizing a memory in the device effectively. CONSTITUTION:A receive buffer F counter 23 and a receive buffer E counter 24 count continuation of a full-state of a receive buffer in a RAM 22c and continuation of a non-full-state. When the contents of the receive buffer F counter 23 reaches a predetermined value, the size of the receive buffer is enlarged so as to smooth printing output of a host computer 1. When the contents of the receive buffer E counter 24 reaches a predetermined value, the size of the receive buffer is contracted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus for receiving print data and recording an image corresponding to the print data on a predetermined recording medium.

[0002]

2. Description of the Related Art Usually, this type of device (simply called a printer) is provided with a reception buffer for temporarily storing received print data. The printer operates so as to sequentially store the received print data in the reception buffer, sequentially read the data from the beginning, and perform the printing process.

By the way, normally, the speed of processing the received data in the printer is much slower than the data transfer speed from the host computer. Therefore, although it is the reception buffer in the printer, the host computer can output the print data at a relatively high speed until the capacity becomes full. However, once the reception buffer becomes full, a signal (so-called busy signal) indicating that data cannot be received is frequently output to the host computer side. Therefore, the print data transfer speed seen from the host computer after that is the processing speed of the printer. Will depend on.

[0004]

As described above, once the reception buffer becomes full, print data can be sent only at a speed depending on the processing of the printing apparatus main body thereafter. From this point of view, if the capacity of the receiving buffer is small, there is a problem in that the host computer is not released from the print data output process.

On the other hand, if the capacity of the receiving buffer is made sufficiently large, the time required from the start of the print processing of the host computer to the release of the print processing is shortened, but not all of the buffer is always used, and most of the time. There is a problem of being wasted.

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide an image recording apparatus capable of smoothing print data output processing of an external device while effectively utilizing a memory inside the device. To do.

[0007]

In order to solve this problem, the image recording apparatus of the present invention has the following structure. That is, in an image recording device that receives print data from an external device and records an image corresponding to the print data on a recording medium, at least a part of the storage device temporarily stores the received data; Of the print data output state, and adjusting means for adjusting the area size of the storage means for storing the print data based on the detection result of the detecting means.

[0008]

In the structure of the present invention, the output status of the print data of the external device is detected, and the size of the print data storage area in the storage means is adjusted based on the detection result.

[0009]

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

FIG. 1 is a block diagram of the printing apparatus of this embodiment. Reference numeral 1 is a host computer for transmitting print data and the like, and 2 is a printing apparatus main body of the embodiment.

In the printing apparatus 2, 21 is an interface (I / F) for receiving data from the host computer, and 22 is a control unit for controlling the entire printing apparatus. The control unit 22 includes a CPU 22a, a ROM 22b that stores various processing programs, font outline data, and the like, and a reception buffer, a font cache buffer, and a RAM 22c that is used as a work area of the CPU 22.

Reference numeral 23 is a reception buffer F counter that counts how long the reception buffer in the RAM 22c is full, and reference numeral 24 is a reception buffer E counter that counts how long the reception buffer is not full.

Reference numeral 25 is a frame buffer capable of expanding one page of print bitmap data, and the pattern expanded here is output to the dot printer engine unit 26 for printing. Although the dot printer engine unit 26 in the embodiment is a laser beam printer, it may be a printer of another type as will be understood from the following description.

Reference numeral 27 is a timer for generating an interrupt signal to the CPU 22a at a predetermined cycle.

An outline of the operation of this embodiment having the above configuration will be described.

In the embodiment, the host computer 1
The data output from the RAM 22c is sequentially stored in the reception buffer in the RAM 22c. At the same time, the unprocessed data in the reception buffer is sequentially read, the corresponding font pattern is expanded in the frame memory 25, and the print processing is performed.
Since the generated font pattern is an outline, it takes some time to generate it. Therefore, in the embodiment, a part of the RAM 22c is used as a font cache. In other words, when the same font pattern as previously generated is generated, the data in the font cache is used.

The larger the area of the font cache and the receive buffer, the more effective it is, but on the other hand, they are not always maximized. In particular, the receive buffer depends on the amount of data sent from the host computer 1, and that amount varies. Therefore, in this embodiment, when it is determined that the print data output process of the host computer 1 is delayed, the operation is performed to secure a large size of the reception buffer (reduce the amount of font cache). This is shown in FIG. 2. By operating in this way, at least the host computer 1
It will be released from the print data output process of itself.

On the contrary, if the reception data is not full for a predetermined period even after the reception buffer size is secured large, the reception buffer size is reduced (the font cache is enlarged). Print processing is performed. In this way, the RAM 22c having a finite capacity is effectively used.

In order to realize the above processing, the control unit 22 (CPU 22a) of the embodiment executes the processing shown in FIGS.

First, the flow chart of FIG. 3 will be described.
This process shows the main routine of the printing process. still,
Although the description goes back and forth, when data is received from the host computer 1, an interrupt signal is supplied from the I / F 21 to the CPU 22a. This interrupt signal causes the CPU
22a fetches data from the I / F 21 and stores it in the RAM 22
Storage processing is performed in the reception buffer in c.

In step S1, one unit of data is read from the reception buffer, and in step S2 it is determined whether or not the font pattern corresponding to the data is in the font cache. When it is determined that the font pattern is not in the font cache, the process proceeds to step S3, the font pattern is generated and registered in the font cache, and the process proceeds to step S4.

When the process proceeds to step S4, in any case, since the corresponding font pattern is stored in the font cache, that pattern is expanded to the corresponding position in the frame memory 25.

Thereafter, in step S25, it is determined whether or not one page of data has been expanded in the frame memory 25, and the processes in and after step S1 are repeated until the expansion process is completed. When one page of data is expanded in the frame memory 25, the frame memory 25
Image data of the dot printer engine unit 26 sequentially
The image is recorded on a recording medium (recording paper) by a known electrophotographic method.

Next, the flowchart of FIG. 4 will be described.
The routine according to this flowchart is executed each time an interrupt signal from the timer 27 is generated, that is, at a predetermined cycle.

First, in step S11, it is determined whether the reception buffer is full of print data. To determine whether or not it is in the full state, the contents of the pointer (not shown) indicating the storage position of the print data and the pointer indicating the data read position in FIG. 3 above may be checked. That is,
When it is determined that the storage pointer of the received data has caught up with the read pointer, the reception buffer is full.

If the receive buffer is full, the process goes to step S12 to clear the receive buffer E counter 24. Then, in step S13, the reception buffer F counter 23 is incremented by "1".

That is, the reception buffer F counter 23 is incremented as long as the reception buffer remains in the full state. To explain in an easy-to-understand manner, how much the value of the reception buffer F counter 23 is the host computer 1
It can be considered as data indicating whether or not the print data output process is delayed.

Next, in step S14, it is determined whether or not the content of the reception buffer F counter 23 has reached a preset maximum value. That is, it is determined whether or not the print data output process of the host computer 1 has been delayed for a predetermined period.

If it is determined that the content of the reception buffer F counter 23 has not reached the maximum value, the interrupt routine process is terminated. If it is determined that the content of the reception buffer F counter 23 has reached the maximum value, the process proceeds to step S15, and the size of the reception buffer of the RAM 22c is increased by a predetermined size (the font cache is reduced by a predetermined size). Then, this means that an empty area has been created in the receive buffer.
In step S16, the reception buffer F counter 23 is cleared, and this interrupt processing ends.

On the other hand, if it is determined in step S11 that the receive buffer is not full, the receive buffer F counter 23 is cleared in step S17, and the receive buffer E counter 24 is incremented by "1" in step S18.

Then, in step S19, the reception buffer E
It is determined whether the value of the counter 24 has reached a preset value. If the reception buffer E counter 24 has not reached that value, this interrupt routine is ended. When the reception buffer E counter 24 reaches that value,
The process proceeds to step S20. Here, the amount of unprocessed data in the reception buffer is checked, and if it is determined that the predetermined size can be reduced, the reception buffer is reduced. Then, in step S21, the reception buffer E counter 24 is cleared.

As described above, according to the present embodiment, the capacity of the receiving buffer of the apparatus is adjusted according to the status of the print data output processing of the host computer 1 so that the memory can be effectively utilized and the host computer The print data output process can be smoothed.

According to the flow chart of FIG. 4 described above, when the receiving buffer is once enlarged and then becomes full again, the enlargement process is performed again. , There is a minimum memory size that must be secured. Therefore, the memory size expansion or contraction processing beyond that is not performed.

Further, in this embodiment, the maximum values of the reception buffer F counter and E counter are internal data, but if these can be specified from the outside such as the host computer, printing with the host within the wait time desired by the user. The communication of the device can be controlled.

Furthermore, in the embodiment, an example in which a part of the RAM 22c is used as a font cache has been described, but the present invention is not limited to this. For example,
In the case of a device that creates internal data in page units from received data and reproduces the internal data or bitmap data, it may be used as an area for creating the internal data. That is, in general, it may be used as a data storage area that must be utilized for print processing.

[0036]

As described above, according to the present invention, the print data output process of the external device can be made smooth while effectively utilizing the memory inside the device.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an image recording apparatus according to an embodiment.

FIG. 2 is a diagram for explaining an adjustment process of a memory 22c in the embodiment.

FIG. 3 is a flowchart for explaining a main routine of the image recording apparatus in the embodiment.

FIG. 4 is a flow chart for explaining an interrupt routine by a timer of the embodiment.

[Explanation of symbols]

1 Host computer 2 printing devices 21 Interface (I / F) 22 Control unit 22a CPU 22b ROM 22c RAM 23 Reception buffer F counter 24 Reception buffer E counter 25 frame buffer 26 Dot Printer Engine 27 timers

Claims (2)

[Claims] 1. An image recording apparatus for receiving print data from an external device and recording an image corresponding to the print data on a recording medium, at least a part of which temporarily stores the received data; An image comprising: a detection unit that detects a print data output status from an external device; and an adjustment unit that adjusts an area size of the storage unit that stores the print data based on a detection result of the detection unit. Recording device. 2. The image according to claim 1, wherein the detecting unit is a unit that clocks a period in a full state and a period in a non-full state of the print data storage area of the storage unit. Recording device.