JPH07210365A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device capable of performing change to an appropriate size by providing a means for detecting that a reception buffer is in a full state and enlarging the size of the reception buffer. CONSTITUTION:A timer 8 is set so as to investigate how long the full state of the reception buffer is continued. The set time of the timer can be set even by commands from an operation panel 11 and a host device 13. When the timer is set, timer interruption is generated after the lapse of the set time and whether or not the next data are taken out from the reception butter during the period is checked by the interruption routine. When it is ascertained that a printer controller takes time in a data processing or the like and a free area is not made in the reception buffer by the checking, a processing for increasing the size of the reception butter is performed. In the case of increasing the area of the reception buffer, whether or not a memory area to be added to the reception butter is a usable area is investigated.

Description

Detailed Description of the Invention

[0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to a digital multi-functional peripheral, a laser printer, a facsimile machine and the like.

[0004]

2. Description of the Related Art Conventionally, there has been known an image forming apparatus such as a laser printer which receives data from a host device and outputs it as image information on a recording sheet. There is also known an image forming apparatus capable of adjusting the image output of the image forming apparatus and the transfer speed of the host apparatus by temporarily storing the transmitted data in the receiving buffer.

[0005]

However, in the conventional apparatus, a memory area prepared as a reception buffer for temporarily storing the image data from the host and a font download are prepared. It was often difficult to use the memory area effectively because it was not coordinated with the memory area. Specifically, the following problems have occurred. A printer will be described as an example.

In the conventional printer, when the receive buffer becomes full, the printer busy (BUS) is used until the data in the receive buffer has been processed to some extent.
Y) was not released. Therefore, when a large amount of complicated data or data that requires a long time for internal processing of the printer is stored in the reception buffer, it takes a considerable time to release the printer-bus, and as a result, The processing of the host device was in a standby state. In such cases,
Depending on the host device, it is often inconvenient that the next work cannot be performed.

Further, the conventional printer does not have a function of adjusting the size of the receiving buffer, that is, the size of the storage area in accordance with the usage state of the receiving buffer, and when a large memory area is allocated to the receiving buffer. However, in the state where the data transmitted from the host device is processed almost without being accumulated in the reception buffer, most of the memory allocated to the reception buffer becomes unnecessary as a result, and the memory is Could not be used effectively.

Further, the conventional printer does not have a function of changing the size of the receiving buffer in accordance with the use status of the memory used for the purpose other than the receiving buffer. So, for example, if the font cannot be downloaded because the font download area is insufficient,
Despite the free area of the receive buffer, the memory area could not be automatically released for downloading. For this reason, the user using the printer fails to download the font, and then reduces the size of the reception buffer by scanning the operation panel in order to increase the download memory of the printer. It was necessary and complicated.

Therefore, an object of the present invention is to solve the drawbacks of the prior art and to obtain an image forming apparatus in which the size of the receiving buffer can be changed to an appropriate size in consideration of the communication with the host device. To do. Another object of the present invention is to provide an image forming apparatus that enables adjustment of a receiving buffer and a memory area used for purposes other than the receiving buffer, and can effectively utilize the memory area on the image forming apparatus. With the goal.

[0010]

The present invention has the following constitution in order to achieve the above object. That is, the image forming apparatus having the receiving buffer for storing the data sent from the host device is provided with means for detecting that the receiving buffer is in the full state and expanding the size of the receiving buffer.

Alternatively, it has means for calculating an unnecessary memory amount in communication with the host device among the memory amounts allocated to the receive buffer, and the size of the receive buffer is required for communication with the host device. If it is larger than the size, the reception buffer size is reduced.

Alternatively, there is provided a means for detecting the use status of a memory area used other than the reception buffer and changing the size of the reception buffer.

[0013]

EXAMPLE An example of the present invention will be described. Figure 1
FIG. 1 is a configuration block diagram of an image forming apparatus according to an embodiment of the present invention. RAM 1 in FIG. 1 is a work memory used by a program, and a data transmitted from the host device.
It is used as a receive buffer that temporarily stores data, a bitmap memory, and font download and font.
It is used for downloading the program.

The CPU 2 controls the operation panel 5 and the printer engine 12 via the engine interface 10 in accordance with the programs stored in the ROM 1.
It executes various controls such as interrupt processing from timer-8. The non-volatile memory 3 includes an EEPROM, a battery-backed-up RAM, and the like. The nonvolatile memory stores printer setting values and maintenance information.

The optional interface 4 is a printer such as an emulation card storing an emulation program corresponding to the command system of various printer models, an expansion memory, a font card storing an expansion font, or the like. It is an interface provided for mounting a controller option. The panel interface 5 is an interface for communicating information with the operation panel 11, and the operation panel is a user interface.
The printer has a display section for displaying the printer status and the like, and an operation section for the user to manually set various printers.

The ROM 7 stores a control program, constant data, font data, pattern data and the like. The timer-8 generates various timer-interrupts under the condition set by the CPU 2.
The host interface 9 is a Centronics interface.
Parallel interface represented by Face, RS
A serial interface represented by 232C or RS422, or a SCSI (Scaldy) interface.
Interface for communication between the host device and the printer controller.

The engine interface 10 obtains information on the status of the printer engine 12, sends a command such as paper feed start from the printer controller to the printer engine, and sends a video signal of the engine. This is an interface for transferring image data developed in a bit map memory in synchronization with.

The host device 13 includes various computers,
It is a word processor, a workstation, etc. and transmits data to be image-formed to the printer. Printer engine 12
Receives a command and image information from the printer controller and forms image information on paper, OHP sheet or the like. The above-mentioned CPU, ROM, RAM, interfaces, etc. are connected via a cat boar bus line.

FIG. 2 is a conceptual block diagram of the receive buffer. The reception buffer 14 is a buffer for temporarily storing the data sent from the host device 13 in the RAM inside the printer controller.

Reference numeral 21 in the drawing is a start address of the memory allocated to the reception buffer. (Hereinafter "HOST_ST
"ART". ) Reference numeral 22 is a pointer for the printer controller to take out the data sent from the host device and stored in the receiving buffer from the receiving buffer for data processing. (Hereinafter referred to as "HOST_GET".)

HOST_GET is incremented by 1 byte each time 1 byte of data is fetched from the reception buffer. Reference numeral 23 is a pointer for storing the data sent from the host in the reception buffer. (Hereinafter, referred to as "HOST_IN".) HOST_IN is incremented by one byte each time 1-byte data is received from the host device.

HOST_GET is a HO represented by reference numeral 24.
Return to HOST_START again at ST_END. However, in order to prevent the data other than the reception data from being erroneously taken out, the processing is performed in comparison with the value of HOST_IN. HOST_IN is a code 2
At HOST_END indicated by 4, again HOST_
Return to START. However, in order to prevent the data which the printer controller has not processed yet from being destroyed, the processing is performed in comparison with HOST_GET.
Here, HOST_END 24 is the last address assigned to the reception buffer.

Regarding the operation of one embodiment according to the present invention,
An explanation will be given based on the flowcharts of FIGS. 3, 4, and 5.

FIG. 3 is a flowchart showing the operation of increasing the size of the reception buffer when the printer controller takes time to process the data and the printer busy of the host interface is not released. It is When the printer controller takes a long time to process the data, the data sent from the host device is accumulated in the receiving buffer, and the receiving buffer is in a so-called full state, the processing time of the data is reduced. This shows an operation of increasing the size of the receiving buffer when the processing time of data is slow, which is estimated by using a timer.

In step 31 (# 31), the cause when the printer is in the busy state is investigated. If the printer is busy because the receive buffer is full,
The process branches to the control of step 32 (# 32). Step 3
2 (# 32), in order to investigate how long the reception buffer is in the full state, the timer-
Set 8. The set time of the timer is the operation panel 11
Alternatively, it can be set by a command from the host device 13. When the timer is set, a timer interrupt occurs after the set time, and the interrupt routine checks whether the next data is taken out from the receive buffer during this time (# 33). In order to check whether the next data has been processed, HOST_GET, HOS
This can be done by checking the value of T_IN or internally providing a flag indicating whether or not the data is taken out.

In step 34 (# 34), the printer controller is de-selected by the check in the previous step.
If it is found that there is no free area in the receive buffer due to time spent on data processing, increase the size of the receive buffer.

This processing is executed by HOST_GET, HOST
Check the _IN status and depending on the status, HOST_END
Is increased or the value of HOST_START is decreased. In some cases, this can be realized by moving effective data for performing these processes in the reception buffer to the increased memory area. Further, even if the addresses are not continuous, it is possible to secure a memory area for the reception buffer in another area. In this case,
It is necessary to add information for managing the receive buffer.

It will be extremely convenient if the user can set how much the receive buffer should be increased by a command from the operation panel or the host device.

When increasing the area of the reception buffer, it is investigated whether or not the memory area added to the reception buffer is an available area. Due to the above operation, it takes time for the internal processing of the printer controller, and the printer
In the case where the above continues, it is possible to receive the data from the host by automatically increasing the size of the receiving buffer.

Next, the printer controller data processing time is short, and the data sent from the host is processed immediately. Therefore, it is detected that most of the receiving buffer area is unnecessary. However, in this case, the operation of reducing the size of the reception buffer and making the surplus area available for other purposes will be described with reference to FIG.

In step 41 (# 41), the number of loops of the processing to be checked is set in the counter in order to detect the state in which the data sent from the host device is hardly accumulated in the reception buffer. . The value of this counter can be set by the device user (user) on the operation panel 11 in FIG. 1 or by a command from the host device.

Step 42 (# 42) is a process for detecting a state where the data sent from the host device is hardly accumulated in the reception buffer. This check is executed the number of times set in the counter at the time interval set in the timer.

In step 43 (# 43), not only is it determined whether or not the receive buffer is full, but it is checked to what extent the receive buffer has a free area. By grasping the free space at each check,
It becomes possible to determine whether the reception buffer can be made smaller.

In step 46 (# 46), the size of the receiving buffer is reduced.
_IN, HOST_GET status, HOST_S
This is possible by changing the values of TART and HOST_END. Further, it is possible to reduce the size of the reception buffer by the amount used by another job, as compared with the memory size required by another job of the printer controller and the memory size that can be reduced from the reception buffer.

As described above, the size of the reception buffer can be reduced by detecting the case where the data sent from the host device is hardly accumulated in the reception buffer.

The operation of the means for reducing the size of the reception buffer, which is judged according to the memory usage, will be described with reference to FIG. FIG. 5 shows that if the memory usage is judged and a memory shortage occurs, it is checked whether the receiving buffer can be made smaller. If the receiving buffer can be made smaller, the receiving buffer is made smaller and the receiving buffer is made smaller. , Operation of allocating a free memory to a place where a memory shortage occurs.

In step 51 (# 51), it is checked whether the memory area of the download font or the download macro or the memory area of the intermediate code used by the printer controller for internal processing is insufficient. ing. Here, the place where the memory shortage occurs is stored in the RAM. If necessary, the insufficient memory is also stored in the RAM. Step 52
In (# 52), the state of the receiving buffer is checked. The state of the reception buffer is known by checking the values of HOST_IN and HOST_GET.

In step 53 (# 53), it is determined whether the size of the reception buffer can be reduced. If it can be reduced, the process proceeds to step 54.

In step 54 (# 54), the free memory due to the reduction of the size of the receiving buffer is allocated to the memory shortage occurrence location detected in step 51.

In the above example, the size of the receiving buffer is reduced. However, the size of the receiving buffer can be increased in accordance with the usage status of the memory.

A timer may not be used to measure the time, and the time may be replaced by a software measurement.

Further, although the present application has been described by using a specific example in which the receiving buffer is set in the RAM, the present invention is not limited to this. For example, when the receiving buffer is provided in the nonvolatile RAM of FIG. It can be applied.

[0043]

As described above, claim 1 of the present invention
According to the above-mentioned invention, when the receiving buffer is full and the processing time of the image forming apparatus is long, the communication with the host apparatus can be restarted by increasing the size of the receiving buffer and the data of the host apparatus can be restarted. Since the time required to complete the data transfer is shortened, the host device can be used for the next work.

According to the second aspect of the present invention, it is possible to calculate an unnecessary memory amount for the receiving buffer and use it for the memory area other than the receiving buffer.
The memory mounted on the image forming apparatus can be efficiently used. On the other hand, according to the invention of claim 3,
Since it is possible to change the size of the receiving buffer by judging the usage status of the memory area other than the receiving buffer, it is possible to avoid the error caused by the memory shortage in advance.

[0045]

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an image forming apparatus of the present invention. FIG. 2 is a conceptual diagram of the reception buffer in the present invention. FIG. 3 is a flowchart showing the operation of the invention described in claim 1. FIG. 4 is a flowchart showing the operation of the invention according to claim 2. FIG. 5 is a flowchart showing the operation of the invention according to claim 3.

[0046]

[Explanation of symbols]

 1 RAM 2 CPU 3 Non-volatile memory 4 Optional interface 5 Panel interface 6 Bus line 7 ROM 8 Timer-9 Host interface 10 Engine interface 11 Operation panel 12 Engine 13 Host device 14 Receive buffer 15 Printer controller

Claims (3)

[Claims] 1. An image forming apparatus having a receive buffer for storing data sent from a host device, comprising means for detecting that the receive buffer is full and expanding the size of the receive buffer. An image forming apparatus characterized by the above. 2. An image forming apparatus having a reception buffer for storing data sent from a host device, wherein a memory unnecessary for communication with the host device out of the memory amount allocated to the reception buffer. An image forming apparatus having a means for calculating the amount, wherein the reception buffer size is reduced when the size of the reception buffer is larger than the size required for communication with the host device. [0001] 3. An image forming apparatus having a reception buffer for storing data sent from a host device, detects the usage status of a memory area other than the reception buffer, and changes the size of the reception buffer. An image forming apparatus comprising: [0002]