JPH05143045A - Image processor - Google Patents

Abstract

PURPOSE:To shorten the processing time and to improve the use efficiency of a memory. CONSTITUTION:When permissible ranges of respective attributes are specified from a host device, etc., the permissible ranges of the respective attributes are set and updated into the specified permissible ranges. Unless the item of the effective attribute is specified from the host device, a font having the attribute within the specified permissible range is selected when present on a font cache memory at the time of the transmission of a font attribute specification command from the host device, but when the item of the effective attribute is specified, a font which has the attribute matching the attribute of the effective item among the attributes specified with the font attribute specification command sent from the host device and the attribute within the permissible range of the attribute except it is selected when present on the font cache memory at the time of the transmission of the font attribute specification command. Then the movement quantity of a print position is set corresponding to the specified attribute and the font on the font cache memory is used to generate and output image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing device such as a page printer such as a laser printer or an ink jet printer or a display device capable of displaying a bitmap, and more particularly to an image processing device equipped with an outline font.

[0002]

2. Description of the Related Art In recent years, in image processing apparatuses such as page printers, an increasing number of fonts are represented by outline information and held. A font represented by this outline information is called an outline font. By using outline fonts, large characters can be printed nicely and fonts with various attributes can be freely created, so that the created document can be made more beautiful and expressive.

However, in order to use the outline font, it is necessary to temporarily convert it into a bitmap, so that the processing time becomes longer than that in the case of printing using a conventional bitmap font, or the bitmap conversion is performed. Requires extra memory to do this. Furthermore, when a large number of fonts are used, there is a problem that the memory capacity becomes insufficient and printing or display becomes impossible.

Therefore, a font that has been bit-mapped once is stored in a font cache memory, which is a temporary storage means, and when printing is performed again using this font, the outline font is not bit-mapped and the font cache is used. An image processing apparatus has also been developed in which a processing time can be shortened by using a bitmapped font stored in a memory.

[0005]

However, since a bitmap font created from an outline font can be created in an infinite number by changing the attributes, even if the fonts are almost the same, if the attributes are different, a new bitmap is newly created. There is a problem that the processing is increased and extra memory is needed because the font is expanded.

The present invention has been made in view of the above points, and an object of the present invention is to realize a reduction in processing time and an improvement in memory usage efficiency in an image processing apparatus using an outline font.

[0007]

In order to achieve the above-mentioned object, the present invention achieves the above object by storing means for storing an outline font, means for converting the outline font stored in the means into a bitmap, and bitmap by the means. In an image processing apparatus equipped with a temporary storage means for temporarily storing the converted font, when a font attribute designation command is sent from a higher-level device, the attributes within the allowable range of each attribute designated by the command are sent. It is provided with a means for determining whether or not a font having "?" Is present in the temporary storage means and, if it is determined to be present, selecting the font and outputting the print data.

Further, among various attribute items such as height, width, inclination, weight, and symbol set, a means for designating a valid attribute item and a case where a valid attribute item is not designated by the means. When a font attribute designation command is sent from the host device, it judges whether a font having an attribute within the allowable range of each attribute designated by the command exists in the temporary storage means, and determines that it exists. If the font is selected, and the item of the valid attribute is designated, when the font attribute designation command is sent from the host device, one of the attributes designated by the command It is judged whether or not a font having an attribute that matches the attribute of a valid item and having an attribute within the allowable range of the attributes excluding the attribute exists in the temporary storage means, and if it exists. When disconnection is also provided that a means for outputting the print data to select the font.

It should be noted that each of the above image processing devices may be provided with means for arbitrarily designating the allowable range of each attribute designated by the font attribute designation command. Also, if the attribute specified by the font attribute specification command and the attribute of the selected font in the temporary storage means are different,
It is desirable to provide means for setting the movement amount of the print position according to the designated attribute.

[0010]

According to the image processing apparatus of the first aspect, when a font attribute designation command is sent from the host device, a font having an attribute within the allowable range of each attribute designated by the command is temporarily stored in the temporary storage means. If it exists, the font is selected and the print data is output, so that the probability of using the font in the temporary storage means increases, the processing time can be shortened, and the memory usage efficiency can be improved, and the user desires. You can get the output.

According to the image processing apparatus of the second aspect, since the item of the valid attribute can be designated in advance, when the item of the valid attribute is not designated, the font attribute designation command is issued from the host device. When a font with an attribute within the allowable range of each attribute specified by the command exists in the temporary storage means when it is sent, select that font, and if a valid attribute item is specified When a font attribute specification command is sent from the host device, it has an attribute that matches the attribute of the valid item among the attributes specified by the command, and is within the allowable range of attributes excluding the attribute. If a font with the attribute of exists in the temporary storage means, that font is selected and the print data is output, so the font with the attribute desired by the user can be selected. It can be and improve performance.

In each of the above image processing apparatuses, if the allowable range of each attribute specified by the font attribute specifying command can be arbitrarily specified, the performance is improved within the allowable range desired by the user and the desired output is obtained. Can be obtained. Also, when the attribute designated by the font attribute designation command and the attribute of the selected font in the temporary storage means are different, the user desires by setting the movement amount of the print position according to the designated attribute. It is also possible to ensure compatibility at the line end.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 2 is a block diagram showing the configuration of a printer with a disk device according to an embodiment of the present invention, which includes a printer controller 1, a printer engine (hereinafter simply referred to as “engine”) 2, a panel device 3, and a disk device 4. Consists of. The host device (host computer) 5 is a host device of this printer.

The printer controller 1 includes a CPU 6, a program ROM 7, a font ROM 8, a RAM 9, and an NV.
It is composed of a RAM 10, an IC card 11, an engine interface 12, a panel interface 13, a disk interface 14, and a host interface 15 (I / F).

The CPU 6 is a central processing unit that controls the printer controller 1 as a whole according to a program in the program ROM 7, a mode instruction from the panel device 3, and a command from the host device 5. Program ROM7
Is a read-only memory that stores the control program of the printer controller 1, a font ROM 8
Is a read-only memory that stores font (outline font) data and the like.

The RAM 9 is a work memory for the CPU 6, an input buffer for temporarily storing input data, a page buffer for storing page data created based on the data temporarily stored in the input buffer, data on the page buffer and font data, etc. It is used for a bitmap buffer for temporarily storing the image image data created by, a font file for storing the fonts downloaded from the host device 5, a font cache memory for temporarily storing the bitmapped fonts, and the like. Random access memory.

The NVRAM 10 is a non-volatile memory for storing the contents of the mode instruction from the panel device 3, and the IC card 11 is a removable memory card used when externally supplying font data and programs. Is. The engine interface 12 is an interface for communicating commands, statuses, and print data with the engine 2 for actual printing, and the panel interface 13 is a panel for notifying the user of the current printer status and giving a mode instruction. Device 3;
It is an interface that communicates commands and status.

The disk interface 14 is an interface for communicating with the disk device 4. The host interface 15 is an interface for communicating with the host device 5, and is usually a Centro I / F or RS.
It is 232C. The disk device 4 is an external storage device that stores various data such as font data, programs, print data, and the like, and is a floppy disk device (FD).
D) and a hard disk device (HDD).

Usually, this kind of printer controller is
Image data (bitmap information) is created according to print data or a control command (control command) from the host device, and printing is performed by outputting this data to the engine. At this time, the print data sent from the host device is sent as a character code, which is interpreted by the controller and the bit-mapped information, that is, the image image data is sent to the engine. By using the font owned by the controller when creating the image data to be sent to this engine, the transmission time from the host device to the printer is shortened.

In the past, image image data was created using a font represented by bitmap information, that is, a bitmap font, but in recent years it has the advantage of improving image quality and saving the amount of data to be retained. A font represented by outline information, that is, an outline font is used.

Although this font has these advantages,
Since it needs to be converted into a bitmap once, it has a drawback that it takes a long processing time. Therefore, we tried to make up for this defect by creating a storage area called a font cache memory that temporarily stores bitmapped fonts. However, since bitmap fonts created from outline fonts can be created almost innumerably by changing the attributes, even if the fonts are almost the same, they will be expanded to bitmap fonts with different attributes, and the processing time will be reduced. It increases or consumes a large memory area.

Therefore, in this embodiment, the CP of FIG.
U6 executes the following processing. The outline of the processing is shown in the flowchart of FIG. In order to simplify the description, the attributes of the designated font are two attributes, height (size) and inclination (italic typeface). Also,
As an initial setting value in the printer controller 1, the allowable range of height is ± 1 point and the allowable range of inclination is ± 10.
Degree. Further, it is assumed that the printer controller 1 is in the print fast mode for printing using the font currently in the font cache memory.

When the character code for printing is received from the host interface 15 following the font attribute designation command (font selection command) that designates a height of 20 points and a tilt of 0 degrees, the font in the font ROM 8 is designated. Bitmaps are made to have attributes, and the bitmapped fonts are expanded in a bitmap buffer on the RAM 9 to create image image data. At that time, the bitmapped font is temporarily stored in the font cache memory.

After that, when the character code is received following the font attribute designation command of height 10 points and inclination 10 degrees, the font cache memory is searched and the height 1
It is determined whether or not a font of a font having a gradient of 10 ± 10 degrees at 0 ± 1 point, that is, a bitmap font is stored. However, since the corresponding font is not yet stored, The font in the font ROM 8 is newly bit-mapped so as to have a specified attribute, the bit-mapped font is temporarily stored in the font cache memory, and image image data is created using the font. ..

After that, if a font having an attribute of ± 1 point specified by the font attribute specification command and an inclination of ± 10 degrees exists in the font cache memory, the font is used to create an image on the bitmap buffer. Create image data. As a result, the time required for bitmapping the outline font is significantly saved, and at the same time, the output desired by the user can be obtained even if the font cache memory capacity is reduced.

It should be noted that some users may definitely want a font having a certain attribute. For example, at least the height of the character may be 10 points. In such a case, the panel device 3 or the host device 5 specifies an item of a valid attribute (an attribute that should be surely acquired), or indicates that the valid attribute must match the designated attribute. To do. It is assumed that the font cache memory stores fonts having a height of 9 points and a tilt of 10 degrees.

Therefore, when the user specifies the height as a valid attribute and the font to be used has a height of 10 points and a tilt of 10 degrees, the CP
When printing, U6 checks whether or not there is a font with a height of 10 points and an inclination of 10 ± 10 degrees in the font cache memory. In this case, the font does not exist, so the font ROM 8 Bitmaps the font so that it has the specified attributes.

Further, the user may want to change the allowable range of each attribute. For example, there is a case where it is desired to print with the height of the character set to the initial value, that is, within ± 1 point as an allowable range and the inclination of the character within an allowable range of ± 10 degrees to ± 30 degrees. In such a case, the panel device 3 or the host device 5 indicates that the inclination of the character is valid if it is within an allowable range of ± 30 degrees. It is assumed that the font cache memory stores fonts having a height of 9 points and a tilt of 10 degrees.

Therefore, the inclination of the character is ± 30 depending on the user.
If it is within the allowable range of degrees, it is indicated that it is effective, and the font to be used has a height of 10 points and an inclination of 10
When the degree font is specified, the CPU 6 checks whether or not there is a font with a height of 10 ± 1 points and an inclination of 10 ± 30 degrees in the font cache memory when printing. In this case, Since the font exists, the image data is created on the bitmap buffer using the font.

By the way, as described above, when the attribute designated by the font attribute designation command and the attribute of the selected font in the font cache memory are slightly different, the last print position of each line is shifted line by line. The output may be difficult to see.

Therefore, the movement amount of the printing position may be set according to the designated attribute. Host device 5
Assuming that the font attribute designation from is a character height of 10 points and a 9-point font is stored in the font cache memory, the CPU 6 creates image image data using the 9-point font. At that time, the printing position is set so that the character spacing is the same as when using a 10-point font. This will give you output with the characters at the end of each line aligned.

FIG. 3 is a block diagram showing another example of the laser printer embodying the present invention. The laser printer 21 includes a printer controller 22, a printer engine 23, and an operation panel (panel device).
It is composed of 24.

Of these, the printer controller 22 converts the data from the host 34 into image image data (video data) and transfers it to the printer engine 23. Further, the data of the font downloaded from the host 34 is stored in the internal RAM, and the print position is controlled and the font is selected by the control command.

The printer controller 22 includes interface circuits of a host interface 25, a panel interface 26, a bus buffer 27, an engine interface 28, a microcomputer (hereinafter referred to as "CP").
U ”), a program ROM 30, a font ROM 31, a RAM 32, and an option RAM 33. The above-mentioned units are mutually connected by a bus line 34 including an address bus, a control bus, and a data bus.

The host interface 25 is a host 34.
It is an interface circuit for transmitting and receiving various control commands and data to and from, and selects various serial interfaces or parallel interfaces according to the host to be connected. The panel interface 26 transmits display control data with the operation panel 24 and receives each key information.

The bus buffer 7 includes a font card 35,
A hard disk device (HDD) 36 and a floppy disk device (FDD) 37 are connected to the bus line 14, respectively, and control various data transmission / reception with them. The engine interface 38 sends and receives data such as command commands and status information to and from the printer engine 23.

The CPU 29 is a general-purpose 16- or 32-bit central processing unit, and controls the overall control of this printer. The program ROM 30 stores a control program for operating the CPU 29, and the font ROM 31 stores resident font (outline font) data.

The RAM 32 is a random access memory and is based on a working memory of the CPU 29, an input buffer for temporarily storing control commands and character data received from the host 34, and control commands and character data temporarily stored in the input buffer. A page buffer for storing page data to be created, a bitmap buffer for temporarily storing image image data created in page units by data on the page buffer and font data, a font for storing download font data received from the host 34 Used for files, font cache memory, etc.

The option RAM 33 is, for example, a non-volatile memory and has set mode information (print format, font selection, emulation selection, resolution selection, host interface selection, etc.).
It also stores service information (error information, operation information, etc.).

The host 34 is a host machine such as an office computer, a personal computer, a word processor, a data processing device, etc., and in order to print the document information and the like created here, control commands and character data etc. corresponding to the printer 1 are printed. To send.

The operation panel 24 has various operation keys for inputting / outputting various information and a display unit. The font card 35 has a built-in RAM or ROM storing optional font data. By inserting into a slot provided on the outer surface of the printer (not shown), the font data can be used for printing.

The printer engine 23 is a laser writing unit that optically scans an internal photoconductor (not shown) with laser light modulated according to image data.
An image forming unit including a photoconductor and each process device around the photoconductor, a mechanism unit including a sheet conveying unit including rollers such as a pair of registration rollers, and an engine driver that is a control unit for the printer controller. The engine driver controls the sequence operation of the image forming unit and the sheet conveying unit and the video modulation signal to the laser writing unit in accordance with a command and image image data from 22 to execute printing.

CPU 2 of this printer controller 22
When the data 9 is received from the host interface 25, the data 9 is first stored in the input buffer provided on the RAM 32. Then, data is sequentially read from the input buffer, command interpretation and character processing are performed, image image data is created in the bitmap buffer on the RAM 32, and the image image data is output from the engine interface 38.

When the outline font is converted into a bit image (bitmap), the coordinate data of the currently selected font is converted into, for example, a font ROM.
By performing coordinate conversion according to the size and direction of the character generated by reading from 31 and generating an outline from the coordinates and performing a filling process inside thereof,
The outline font can be converted into a bit image.

Here, the processing speed of this laser printer will be described. For example, considering the case of 16 PPM (16 pages per minute), it is simply 3.75 per page.
It must be processed in seconds (60/16 = 3.75). And if you have to process 3000 characters per page, 1.2 per character
If the above process is not performed in 5 msec (3.75 / 3000 = 1.25), the speed of the printer cannot be met.

Therefore, conventionally, the outline font is converted into a bit image in advance and stored in the RAM 32 in a font cache memory which is secured separately from the bit map buffer, and all the necessary characters are stored in the bit image as a bit image ( In other words, image data can be created with the same processing as conventional bitmap fonts), and the print speed is supported.

By the way, bit images of selected fonts are sequentially stored in a font cache memory secured in advance in the RAM. At that time, RAM
When a storage medium other than the above is provided, when the memory capacity of the RAM becomes full, the fonts selected next are sequentially stored in that storage medium. However, in such a method, since the access speed is slow depending on the storage medium, even if the font is converted into a bit image and held (hereinafter, also referred to as “cashing”), the effect may not be sufficiently exerted.

Therefore, in the laser printer of FIG.
As shown in the flowchart of FIG. 5, the usage frequency of the selected font is managed, and the storage medium to be cached is selected according to the usage frequency. That is, when the memory capacity of a certain storage medium becomes full, the bit images of frequently used fonts are stored in the storage medium with high access speed, and the bit images of rarely used fonts are stored in the storage medium with low access speed. By storing the data, the printing speed of the memory can be improved.

Here, a concrete example will be described. As for the outline font, 35 fonts from font 1 to font 35 are stored in the font ROM 31, and 15 fonts from font 36 to font 50 are stored in the hard disk in the hard disk device 36, and there are a total of 50 fonts. To do. The access speed of each storage medium is assumed to be in the following order. Further, it is assumed that the RAM 32 has a free capacity for caching for 4 fonts. RAM32> Hard disk> Floppy disk

CPU 29 in printer controller 22
Creates a usage management table shown in FIG. 5 when a font select command is sent from the host 34 and an outline font is developed into a bit image. The storage area of this table is secured in the RAM 32 in advance.

In the usage management table of FIG. 5, the first ROM or HD is the font ROM.
Fonts stored in 31 or hard disk device 3
It is for identifying whether it is a font stored in the hard disk in 6. This is because basically the frequently used fonts are stored in the ROM, and the other fonts are optionally stored in the hard disk. Here, the font ROM 31 is defined as "0", and the hard disk is defined as "1".

The next number of times of use is "1" when the font is developed into a bit image and is incremented (+1) each time it is used for printing. The larger the number, the number of times of use. Indicates that there are many. The next use number is to put the numbers in the order used for printing. In short, it is known that the one with the highest number is the font used now, the smaller the number, the earlier. It turns out that it was used.

Each item of this usage management table is RAM3.
It is assumed that the priority order is given to the order of storing in 2. That is, the item of ROM or HD has the first priority. Here, RAM 32 (font cache memory)
Assume that 4 fonts have already been cached. Each of the stored fonts is font 1, font 2, font 40, font 50.
In addition, the usage management table is created as shown in FIG.

If font 3 is selected in this state, first, a font for which the item of ROM or HD in the use management table is "1" is found. Therefore, it can be seen that there are two targets, font 40 and font 50, which move in the cache area. Next, when the number of times of use is judged, since both are "1", the numbers used are compared. Therefore, since the font 40 has a smaller value, it can be seen that it has been used before.

Therefore, the bit image of the font 40 is taken out from the RAM 32 and stored again in the hard disk in the hard disk device 36 with a slow access time.
The bit image of font 3 is stored in the RAM 32.
This operation is first performed between the RAM 32 and the hard disk, and then, when the free space of the hard disk is exhausted, the floppy disk inserted in the floppy disk device 37 is also taken into consideration, and caching is performed by the same judgment.

As described above, in this laser printer, the higher the frequency of use, the more frequently the data is stored in the storage medium having the faster access time based on the information in the use management table, so that the caching efficiency can be maximized. ,
Throughput of the entire apparatus is improved, and the storage medium can be effectively used. This laser printer also performs the same processing as that of the above-described embodiment described with reference to FIGS. 1 and 2, but the description thereof is omitted.

The embodiments in which the present invention is applied to a laser printer have been described above. However, the present invention is not limited to this, and it is not limited to page printers such as LED printers, liquid crystal shutter printers and ink jet printers, as well as digital copying machines and facsimiles. The present invention can be applied to various types of image processing devices such as a device and further a display device capable of displaying a bitmap.

[0058]

As described above, according to the present invention, it is possible to shorten the processing time and improve the memory usage efficiency in the image processing apparatus using the outline font.

[Brief description of drawings]

FIG. 1 is a flow chart showing a process according to the present invention by a CPU 6 of FIG.

FIG. 2 is a block diagram of a laser printer showing an embodiment of the present invention.

FIG. 3 is a block diagram of a laser printer showing another embodiment of the present invention.

FIG. 4 is a flowchart showing font caching processing by a CPU 29 of FIG.

5 is a memory map diagram showing an example of a usage management table in the laser printer of FIG.

FIG. 6 is a memory map diagram showing an actual usage example of the usage management table.

[Explanation of symbols]

 1 Printer Controller 2 Printer Engine 3 Panel Device 5 Host Device 6 Central Processing Unit 7 Program ROM 8 Font ROM 9 RAM 10 NVRAM 11 Host Device

Claims (4)

[Claims] 1. A storage unit for storing an outline font, a unit for converting the outline font stored in the unit into a bitmap, and a temporary storage unit for temporarily storing the font converted into a bitmap by the unit. In a provided image processing apparatus, when a font attribute designation command is sent from a higher-level device, it is determined whether a font having an attribute within an allowable range of each attribute designated by the command exists in the temporary storage means. An image processing apparatus comprising means for selecting the font and outputting print data when it is judged that the font exists. 2. A storage means for storing the outline font, a means for converting the outline font stored in the means into a bitmap, and a temporary storage means for temporarily storing the font converted into the bitmap by the means. In the provided image processing apparatus, a means for designating a valid attribute item among various attribute items such as height, width, inclination, weight, and symbol set, and a valid attribute item is not designated by the means. In this case, when a font attribute designation command is sent from the host device, it is determined whether or not a font having an attribute within the allowable range of each attribute designated by the command exists in the temporary storage means, If it is determined that the font exists, the font is selected, and if the item with the valid attribute is designated, the font attribute is designated from the host device. When a command is sent, a font having an attribute that matches the attribute of the valid item among the attributes specified by the command and that has an attribute within the allowable range of attributes excluding the attribute is temporarily stored. Judge whether it exists in the means,
An image processing apparatus comprising means for selecting the font and outputting print data when it is determined that the font exists. 3. The image processing apparatus according to claim 1, further comprising means for arbitrarily designating an allowable range of each attribute designated by the font attribute designation command. 4. The image processing apparatus according to claim 1, wherein the attribute designated by the font attribute designation command and the attribute of the selected font in the temporary storage means are different. An image processing apparatus comprising means for setting a movement amount of a print position according to the designated attribute.