JP2002052763A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a printer which is adapted to shorten a time before images are outputted by increasing an image-processing speed through effective utilization of a memory when the memory of not smaller than a necessary minimum capacity for outputting images is loaded. SOLUTION: There are provided a memory capacity-detecting means 8 for detecting a storage capacity of a RAM 3 and a paper size-estimating means 9 for estimating a size of output papers to be printed by a printing mechanism. A control means allots the storage capacity of the RAM 3 as a page memory for storing image data compressed by a compressor 6 in accordance with the paper size estimated by the paper size-estimating means 9, and allots the remaining storage capacity for processing images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus capable of switching an image printing density, and more particularly to a printing apparatus in which a memory is effectively used to increase an image processing speed.

[0002]

2. Description of the Related Art Conventionally, image data divided for each predetermined line sent from a host device is compressed by a predetermined compression method and stored in a page memory in a printer controller.
In a laser printer controller that decompresses compressed data and sends it to a printer engine, the memory capacity mounted on the controller is smaller than that of a method that does not use compression, and the frame buffer area for storing print data is also smaller. . For this reason, even when compression is performed and stored in the frame buffer, an error may occur because the image cannot be stored in the frame buffer depending on the type of image. As a countermeasure against this, there is a device provided with a slot for increasing a memory mounted on the controller. Here, if the memory of the controller is added, the error that occurred until now will no longer be an error.However, if the memory is added more than necessary, the memory will be wasted. The advantage of is lost.

[0003]

As described above, in the conventional printing apparatus, it is possible to prevent the problem that the image data cannot be stored in the memory if the memory is added.
Normally, most of the added units are wasted and left unused without being used effectively. The present invention has been made in order to solve this problem, and a memory in a controller is added by a user and a memory having a memory capacity more than a minimum memory capacity necessary for image output is mounted. In such a case, it is an object to realize a printer device that aims to increase the image processing speed and shorten the time until image output by effectively using a memory.

[0004]

In order to achieve the above object, the present invention relates to a compression means for compressing image data divided by a predetermined number of lines sent from a host device such as a computer in accordance with a predetermined compression method. A storage unit having a part of its storage capacity allocated as a page memory for storing image data compressed by the compression unit and another part for image processing; and a compressed image stored in a page memory part of the storage unit. In a printing apparatus comprising: a decompression unit for reading and decompressing data; a data transfer unit for transmitting image data decompressed by the decompression unit to a printing mechanism; and a control unit for controlling each of these units. Storage capacity detection means for detecting storage capacity; and paper size prediction means for predicting the size of output paper printed by the printing mechanism. And Bei, and the control means to allocate allocated remaining storage capacity storage capacity in the page memory of the storage means in accordance with a paper size to be predicted the paper size predicting means for image processing. Accordingly, it is possible to realize a printing apparatus that can use a memory capacity of the storage unit that is equal to or more than the necessary minimum to increase the image processing speed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a CPU, which performs system control, image processing, and the like of the entire apparatus. Reference numeral 2 denotes a ROM in which programs executed by the CPU 1 and various parameters are stored. Symbol 3 is RA
M is used for work when processing control codes and images, and is used for temporarily storing image data and the like obtained by processing the print data by the CPU 1.

Reference numeral 4 denotes a host interface for exchanging print commands and commands with the host device. Reference numeral 5 denotes an engine interface, which is a connection portion for sending commands and print data to the printer engine. Reference numeral 6 denotes a compressor, which compresses image data sent from the host device and stores it in a page memory. Reference numeral 7 denotes a decompressor, which has a function of decompressing the compressed image data in the page memory and transmitting the decompressed image data to the printer engine. Reference numeral 8 denotes a memory capacity detecting means for detecting a memory capacity mounted on the controller. Reference numeral 9 denotes paper size prediction means for predicting the size of paper to be printed.

In the present invention, the total memory capacity obtained by using the memory capacity detecting means 8 is distributed so that the processing speed becomes the highest according to the paper size predicted by the paper size predicting means 9. Here, the memory area to be allocated includes a receiving buffer for storing a command sent from the host device via the host interface 4, and a work for analyzing the contents of the command in the receiving buffer to create print data. And a cache memory for character fonts, images, and graphics for creating print data at high speed, and a page memory for storing print data. According to the present invention, an area corresponding to the predicted paper size is secured in the page memory, and the remaining area is stored in the reception buffer, the work memory,
Operate to allocate to cache memory. This operation will be described below.

The operation of this embodiment will be described with reference to the flowchart of FIG. In this embodiment, first, in step 101, the total memory capacity is checked using the memory capacity detecting means 8. Then, in step 102, the paper size is predicted using the paper size prediction means 9, and in step 103, the memory area is allocated according to the paper size so that the processing speed is the fastest. For example, when the memory in the controller is not added, the capacity of the reception buffer is 64 kB, 10 MB is allocated to the page memory, 3 MB is allocated to the work memory, and 2 MB is allocated to the cache memory. When the memory is added, the memory allocation to all these areas is increased to improve the performance and improve the processing speed.

Next, the operation of another embodiment of the present invention will be described with reference to the flowchart of FIG. In this embodiment, the paper size data at the time of previous printing is stored in a nonvolatile memory in the controller. In step 201, the total memory capacity is checked using the memory capacity detecting means 8. Then, in step 202, the paper size estimating means 9 reads out the paper size data at the time of previous printing stored in the nonvolatile memory in the controller. In step 203, the paper size is used as the current paper size prediction data. In step 204, the memory area is allocated according to the paper size so that the processing speed is the highest. Actually, printing is often performed with the paper size printed last time, so that optimization according to the actual situation is performed by performing optimization according to the paper size last time.

Next, the operation of still another embodiment of the present invention will be described with reference to the flowchart of FIG. In this embodiment, storing the paper size data at the time of printing in the nonvolatile memory in the controller is repeated a plurality of times, and the paper size data for a plurality of times is stored in a fixed area of the nonvolatile memory. In step 301, the total memory capacity is checked using the memory capacity detecting means 8. Then, in step 302, the paper size prediction means 9 reads out the paper size data for a plurality of times of printing stored in the nonvolatile memory in the controller. Then step 303
Then, among the plurality of paper sizes, the paper size with the largest number of uses is used as the prediction data.
According to the paper size, the memory area is allocated so that the processing speed is the fastest.

According to the present invention, it is possible to prevent the overflow of the page memory at the time of memory expansion and the like and to effectively utilize the surplus memory capacity to improve the processing capability and the processing speed by the above-described measures. Become.

[0013]

As described above, according to the first aspect of the present invention, there is provided a compressing means for compressing image data transmitted from a host device such as a computer for each predetermined number of lines in accordance with a predetermined compression method. A storage unit having a part of its storage capacity allocated as a page memory for storing image data compressed by the compression unit and another part for image processing; and a compressed image stored in a page memory part of the storage unit. A printing apparatus comprising: a decompression unit for reading and decompressing data; a data transfer unit for transmitting image data decompressed by the decompression unit to a printing mechanism; and a control unit for controlling each of these units. A storage capacity detecting means for detecting a capacity; and a paper size estimating means for estimating a size of an output paper to be printed by the printing mechanism. Stage is characterized by allocating the allocated remaining storage capacity storage capacity in the page memory of the memory means in accordance with a paper size to be predicted paper size predicting means for image processing. This makes it possible to distribute the storage capacity so that the processing speed is the fastest with the paper size predicted by the paper size prediction means, thereby preventing overflow of the page memory and increasing the remaining memory capacity when, for example, adding a memory to the control unit. Can be effectively used, the effect of memory expansion can be enhanced, data processing can always be performed in accordance with the memory capacity, and a printing apparatus capable of shortening the time until printing is completed can be realized.

The invention according to a second aspect of the present invention is characterized in that the paper size predicting means sets the size of the output paper used in the previous printing as the predicted paper size. This makes it possible to distribute the storage capacity so that the processing speed is the fastest with the paper size predicted by the paper size prediction means, thereby preventing overflow of the page memory and increasing the remaining memory capacity when, for example, adding a memory to the control unit. Can be effectively used, the effect of memory expansion can be enhanced, data processing can always be performed in accordance with the memory capacity, and a printing apparatus capable of shortening the time until printing is completed can be realized. At this time, since the previous paper size data is stored and used as the paper size prediction means, the paper size can be predicted by a simple process of reading the paper size with a small hardware configuration. It is possible to realize a paper size estimating means capable of performing the above.

The invention according to a third aspect of the present invention is characterized in that the paper size estimating means sets the size of the output paper used most in several past printings as the estimated paper size. This makes it possible to distribute the storage capacity so that the processing speed is the fastest with the paper size predicted by the paper size prediction means, thereby preventing overflow of the page memory and increasing the remaining memory capacity when, for example, adding a memory to the control unit. Can be effectively used, the effect of memory expansion can be enhanced, data processing can always be performed in accordance with the memory capacity, and a printing apparatus capable of shortening the time until printing is completed can be realized. At this time, the paper size estimating means uses the size data of the most frequently used output paper in the past several times of printing, so that the paper size can be estimated with high accuracy by a relatively simple process with a small hardware configuration. Thus, the probability of printing at the predicted paper size increases, and high-speed printing according to the paper size can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a printing apparatus according to the present invention.

FIG. 2 is a flowchart illustrating an operation of the printing apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of another embodiment of the printing apparatus of the present invention.

FIG. 4 is a flowchart showing the operation of another embodiment of the printing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 ROM 3 RAM 4 Host interface 5 Engine interface 6 Compressor 7 Decompressor 8 Memory capacity detection means 9 Paper size prediction means

Claims (3)

[Claims] 1. A compression means for compressing image data divided by a predetermined number of lines sent from a host device such as a computer in accordance with a predetermined compression method, and a part of the storage capacity of the image data compressed by the compression means. Means for assigning another part for image processing as a page memory for storing the image data, decompression means for reading and expanding the compressed image data stored in the page memory part of the storage means, and decompression by the decompression means A printing device comprising: a data transfer unit that sends the image data to the printing mechanism; and a control unit that controls these units. A storage capacity detection unit that detects a storage capacity of the storage unit. Paper size estimating means for estimating the size of the output paper to be printed, wherein the control means A printing apparatus, wherein the storage capacity of said storage means is allocated to said page memory in accordance with the paper size to be measured, and the remaining storage capacity is allocated for image processing. 2. The printing apparatus according to claim 1, wherein the paper size prediction unit sets the size of the output paper used in the previous printing as the predicted paper size. 3. The printing apparatus according to claim 1, wherein the paper size estimating unit sets the estimated paper size to the size of the most frequently used output paper in past several times of printing.