JP2657138B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer adopting a band map memory system.

[0002]

2. Description of the Related Art A typical method of managing a bit map memory of a printer includes a full bit map system and a band map memory (partial bit map) system.
The full bitmap system is a system in which print data is developed in a bitmap memory having a capacity necessary for developing a bitmap of print data for one page of printing paper. The band map memory system is one of the printing papers.
In this method, print data is developed by using a bitmap memory having a smaller capacity than that required for developing bitmap print data for a page.

In a printer adopting a band map memory system, a storage area of a bit map memory is divided into two areas having the same capacity, and print data for a required print range of recording paper to be developed this time is stored in one area. Is developed, bitmap data for the required printing range that has been previously developed is transferred from the other area to the printer engine. When the bitmap data for the required print range previously developed from one area is transferred to the printer engine, the print data for the next required print area is developed in that area, and the print data for this time is developed from the other area. The bit map data for the required print range is transferred to the printer engine.

[0004]

The time required to develop print data for the required print range in one of the two storage areas of the bitmap memory is usually from the other area for the required print range. It is shorter than the time required to transfer the bitmap data to the printer engine. Therefore, by the time the bit map data for the required print range is transferred from one of the two storage areas of the bit map memory to the printer engine, the development of the print data for the required print range to the other area is completed. .

[0005] However, when an image in a required printing range on a recording paper is very complicated, it takes a longer time to develop print data for the required printing range. Then, the time required to develop the print data for the required print range in which the image is complicated in one of the two storage areas of the bit map memory is changed from the other area to the bit map for the required print range previously developed from the other area. It can be longer than the time required to transfer data to the printer engine.

In such a case, while the print data for the required print range in which the image is complicated is being developed in one area, the print data for the last required print area developed to the printer engine from the other area is being developed. The transfer of the bitmap data ends, and the data transfer from the area where the print data is currently expanded to the printer engine starts. Such a state is called a band bitmap error.

When a band bitmap error occurs,
Bitmap data may be transferred from a storage location where print data for the required print range to be transferred this time has not been expanded yet. Then, the printing result of the recording paper in the corresponding required printing range becomes an incomplete image in which a part of the image is missing. When the print image becomes incomplete due to the occurrence of the band bitmap error, it is difficult for the user to grasp the cause, and there is a problem that an appropriate measure cannot be taken.

An object of the present invention is to provide a printer capable of detecting occurrence of a band bitmap error.

Another object of the present invention is to provide a printer capable of notifying the occurrence of a band bitmap error when it occurs.

It is still another object of the present invention to provide a printer which can automatically stop a printing operation when a band bitmap error occurs.

[0011]

A printer according to the present invention has two bitmap storage units of the same capacity, and print data is alternately bitmap-developed into these bitmap storage units by a required print range. In a printer adopting a band map memory system, in which bit map data is transferred from these bit map storage means to the printer engine, a time is counted each time bit map development of print data for a required print range starts. It starts and is reset when the bitmap development is completed, and the time counted by the timer reaches a predetermined reference time required to transfer the bitmap data for the required print range. To detect when a band bitmap error has occurred. The features.

It is preferable to provide a notifying means for notifying that a band bitmap error has occurred when it is detected that a band bitmap error has occurred. Further, it is preferable to provide a means for stopping the printing operation when it is detected that a band bitmap error has occurred.

[0013]

In the printer according to the present invention, each time the bit map development of the print data for the required print range is started, the timer means starts counting time. This timer is reset when the bitmap development is completed. Then, when the time counted by the timer reaches a predetermined reference time required to transfer the bitmap data for the required printing range, it is detected that a band bitmap error has occurred. .

When the occurrence of the band bitmap error is detected, for example, the occurrence of the band bitmap error is notified by the notifying means,
The printing operation is stopped.

[0015]

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

1 to 4 show a first embodiment of the present invention.

FIG. 1 shows the configuration of the printer.

The printer is controlled by the CPU 10. The CPU 10 includes a host interface 11 to which a host computer (not shown) is connected, a program ROM 12 for storing programs of the CPU 10, a font ROM 13 for storing font data, and a RAM 14 for storing various data.

The RAM 14 has a full bitmap development area E1 used as a bitmap memory when the full bitmap system is adopted, an area E2 used as a character descriptor table when the band bitmap system is adopted, and a band. There are provided first and second band bitmap development areas E11 and E12 used as a bitmap memory when the bitmap method is adopted, an area E3 used as a bitmap development flag F, and the like.

When the band bitmap method is adopted, the entire printing range of the size of the recording paper necessary for printing is divided into several bands (a plurality of required printing ranges), and each band is divided into several bands. A character descriptor including the type of data to be printed at the position of the band, the data source, the printing position, and the like is stored in the character descriptor table. In this embodiment, it is assumed that the entire printing range of the size of the recording paper required for printing is divided into 20 bands.

Each band bitmap development area E11,
The capacity of E12 is equal, and data of one band is bitmap-developed in each band bitmap development area E11, E12. The character descriptor includes, for example, font attributes, height, width, source, bit alignment, target, and link pointer data.

The printer further includes an operation panel 15 having various operation keys including a bitmap mode selection key for selecting one of a full bitmap system and a band bitmap system, a display, etc., and a printer engine for performing printing. 19, a DMA controller 16 for transferring the bitmap data developed in the full bitmap development area E1 or the band bitmap development areas E11 and E12 to the printer engine 19, and first and second registers 17 and 18. ing.

FIG. 2 shows the procedure of the character descriptor table creation processing by the CPU 10.

When image data is sent from the host computer via the host interface 11 (step 1), it is determined whether the sent data is print data or control data (step 2). If it is control data, a command process according to the control data is performed (step 3), and the process returns to step 1.

If the transmitted data is print data, it is determined whether the full bitmap mode or the band bitmap mode is selected (step 4), and the full bitmap mode is selected. If so, the print data is bitmap developed in the full bitmap development area E1 in the RAM 14 (step 5), and the process returns to step 1.

If the band bitmap mode is selected, it is calculated to which band the print position of the transmitted print data belongs (step 6). Also,
A character descriptor for the sent print data is created (step 7). Then, the character descriptor created in step 7 is stored in RAM1
4 is stored in the storage area of the character descriptor table corresponding to the band calculated in step 6 (step 8). Then, the process returns to step 1.

FIG. 3 shows the CPU 10 when the printing operation is started when the band bitmap mode is selected.
3 shows a bitmap expansion processing procedure performed by the above.

First, the bitmap developing flag F is reset (step 11). Then, based on the character descriptor corresponding to the first band in the character descriptor table, the bitmap corresponding to the first band is developed in the first band bitmap development area E11 (step 12). When the bitmap development corresponding to the first band is completed (step 1
3) Based on the character descriptor corresponding to the second band, the second band bitmap development area E
A bitmap corresponding to the second band is developed in 12 (step 14).

When the bitmap development corresponding to the second band is completed (step 15), the printer engine 1
9, a print start command is output (step 16). Further, a command to start transfer of bitmap data corresponding to the first band developed in the first band bitmap development area is output to the DMA controller 16 (step 17).

When a transfer start command for the bitmap data in the first band bitmap development area E11 is output to the DMA controller 16, the DMA controller 16 transfers data to the first and second registers 17 and 18. That is, first, the bitmap data developed in the first band bitmap development area E11 is 1 bit.
The words are read and written to the first register 17. After one word of bitmap data is written into the first register 17, the printer engine 1
At the same time as the bitmap data is transferred to the register 9, the bitmap data for the next one word in the first band bitmap development area E 11 is read and transferred to the second register 18.

From the first register 17, the printer engine 1
When the transfer of the bitmap data to the first register 17 is completed, the first band bitmap development area E1
Bitmap data for one word from 1 is transferred, and bitmap data from the second register 18 to the printer engine is transferred. Thus, the first
The transfer of the bitmap data from the band bitmap development area E11 to one register and the transfer of the bitmap data from the other register to the printer engine 19 are performed alternately. Then, all the bitmap data (bitmap data corresponding to the first band) developed in the first band bitmap development area E11 are transferred to the printer engine 1 via the registers 17 and 18.
9, the DMA controller 16 sends C
A transfer end signal is sent to PU10.

FIG. 4 shows an interrupt processing procedure performed by the CPU 10 when a transfer end signal is sent from the DMA controller 16 to the CPU 10 when the band bit map mode is selected.

First, the first interrupt processing after the start of the printing operation will be described.

When the bitmap developing flag F is set (F
= 1) or reset (F = 0)
Is determined (step 21). Since the bitmap developing flag F is reset in step 11 described above,
In the first interruption process based on the transfer end signal from the DMA controller 16 to the CPU 10 after the start of the printing operation, the bitmap developing flag F is reset. Therefore, the first DMA after the start of the printing operation
In the interrupt processing based on the transfer end signal from the controller 16 to the CPU 10, the process proceeds to step S22.

In step 22, a command to start transfer of bitmap data (bitmap data corresponding to the second band) in the second band bitmap development area E12 is output. When a transfer start command of the bitmap data in the second band bitmap development area E12 is output to the DMA controller 16, the DMA controller 1
6 to the first and second registers 17 and 18. This DMA data transfer is the same as the transfer processing of the bitmap data corresponding to the first band described above except that the data transfer source is the second band bitmap development area E12, and thus the description thereof is omitted.

Next, the first band bitmap development area E11 is cleared (step 23). Then, after the bitmap developing flag F is set (F = 1) (step 24), the bitmap corresponding to the third band in the first band bitmap developing area E11 is started (step 25). ).

First band bitmap development area E11
Is completed (step 26).
The bitmap developing flag F is reset (F = 0) (step 27), and the current interrupt processing ends.

When the DMA transfer is completed based on the transfer start command to the DMA controller 16 in step 25, a transfer end signal is sent from the DMA controller 16 to the CPU 10. DMA controller 16 to CPU 1
When the transfer end signal is sent to 0, interrupt processing is performed again.

The second and subsequent interrupt processes after the start of the printing operation will be described.

First, whether the bitmap developing flag F is set (F = 1) or reset (F
= 0) is determined (step 21). If the bitmap developing flag F is reset, the DM based on the transfer start command in the previous interrupt processing in the first and second band bitmap developing areas E11 and E12.
A command to start transferring bitmap data in a band bitmap development area different from the band bitmap development area for which the A transfer has been completed is output to the DMA controller 16 (step 22). When a transfer start command is output to the DMA controller 16, data transfer to the printer engine 19 via the first and second registers 17 and 18 by the DMA controller 16 is performed.

Next, of the first and second band bitmap development areas E11 and E12, a band bitmap development area different from the band bitmap development area for which DMA transfer has been started in step 22 is cleared (step S12). 23).

After the bitmap developing flag F is set (F = 1) (step 24), step 2 is executed.
Bitmap development corresponding to the next band in the band bitmap development area cleared in 3 is started (step 25). When the bitmap expansion started in step 24 is completed (step 26), the bitmap expansion flag F is reset (F = 0) (step 2).
7), the current interrupt processing ends.

If the bitmap developing flag F is set (F = 1) in step 21, the process proceeds to step 28. The case where the bitmap developing flag F is set (F = 1) in the above step 1 means that the DM based on the transfer start command in step 22 of the previous interrupt processing is performed.
At the time when the A transfer is completed, the bitmap expansion started in step 25 of the previous interrupt processing has not been completed, and a band bit error has occurred. That is, while the bitmap data is being developed in one of the first and second band bitmap development areas E11 and E12, the bitmap data from the other band bitmap development area is being developed. This is a case where the DMA transfer is completed and the current interrupt processing is started.

In such a case, a transfer stop command is output to the DMA controller 16 (step 2).
8) The fact that a band bitmap error has occurred is displayed on the display provided on the operation panel 15 (step 29), and the current interrupt processing ends.

In step 28, the DMA controller 1
When the transfer stop command is output to 6, the DMA transfer is stopped, so that subsequent printing is not performed. The transfer stop command to the DMA controller 16 may be released when data of the page next to the page currently being printed is sent from the host computer. By doing so, printing from the next page becomes possible.

In step 28, the DMA controller 1
Alternatively, a print stop command may be output to the printer engine 19 instead of, or in addition to, outputting the transfer stop command to the printer engine 6.

FIGS. 5, 6, 7 and 8 show a second embodiment of the present invention. In the second embodiment, the bitmap developing flag F is unnecessary. The ROM 12 has 1
A reference value TRo corresponding to the time (DMA transfer time TR) required for DMA transfer of bitmap data from all storage locations of the one band bitmap development area E11, E12 is stored in advance. RAM14
Includes the band bitmap development areas E11 and E12
There is provided a counting area (not shown) which is used as a counter for measuring a time (bitmap development time TW) for developing the bitmap after the start of the bitmap development.

Each time the bitmap development is started, it is monitored whether or not the bitmap development time TW reaches the DMA transfer time TR.
When the A transfer time TR has been reached, it is detected that a band bitmap error has occurred. That is, when the bitmap development time TW reaches the DMA transfer time TR, the first
And second band bitmap development areas E11 and E1
2 while bitmap data is being developed in one band bitmap development area, D of bitmap data from the other band bitmap development area.
It is detected that the MA transfer has been completed.

FIG. 5 shows the procedure of the character descriptor table creation processing by the CPU 10. Since this processing procedure is the same as the processing procedure shown in FIG. 2 of the first embodiment, the same steps are denoted by the same step numbers and description thereof is omitted.

FIG. 6 shows the CPU 10 when the printing operation starts when the band bitmap mode is selected.
3 shows a bitmap expansion processing procedure performed by the above. This processing procedure is the same as the processing procedure shown in FIG. 3 of the first embodiment except that the process of resetting the bitmap developing flag F in step 11 in the processing procedure shown in FIG. 3 of the first embodiment is not performed. Therefore, the same steps are denoted by the same step numbers and description thereof is omitted.

FIG. 7 shows an interrupt processing procedure performed by the CPU 10 when a transfer end signal is sent from the DMA controller 16 to the CPU 10 when the band bit map mode is selected.

In this process, first, of the first and second band bitmap development areas E11 and E12, transfer of bitmap data in a band bitmap development area different from the band bitmap development area for which DMA transfer has been completed last time. Start command is DMA controller 16
(Step 31). DMA controller 1
When the transfer start command is output to the CPU 6, the DMA controller 16 transfers data to the printer engine 19 via the first and second registers.

Next, of the first and second band bitmap development areas E11 and E12, a band bitmap development area different from the band bitmap development area in which DMA transfer has been started based on the transfer start command in step 31 described above. Is cleared (step 32).

Next, bitmap development to the band bitmap development area cleared in step 32 is started (step 33). Then, when the bitmap development is completed (step 34), the current interrupt ends.

FIG. 8 shows parallel processing performed by the CPU 10 every time bitmap development is started when the band bitmap mode is selected. This process is performed every time bitmap development is started in steps 12 and 14 of FIG. 6 and step 33 of FIG.

First, it is determined whether or not a predetermined time has elapsed (step 41).
Of the counting area used as the counter of No. 4
Wx is incremented (+1) (Step 4)
2). The count value TWx of the counter is equal to the reference value T.
It is determined whether or not Ro has been reached, that is, whether or not the bitmap development time TW has reached the DMA transfer time TR (step 43).

The count value TWx of the counter is equal to the reference value TR.
o, that is, when the bitmap development time TW has not reached the DMA transfer time TR,
It is determined whether or not the bitmap development to the band bitmap development area currently being performed has been completed (step 44). If not completed, the process returns to step 41.

Therefore, when the bitmap development is started, the processing of steps 41, 42, 43 and 44 is repeated. If it is determined in step 44 that the bitmap development has been completed, it is determined that the time TW required for bitmap development in the band bitmap development area is shorter than the DMA transfer time TR, and the counter is reset. (TWx = 0) (step 45), and the current parallel processing ends.

At step 43, the count value T of the counter
When Wx reaches the reference value TRo, that is, when the bitmap development time TW reaches the DMA transfer time TR, it is determined that a band bitmap error has occurred, and a print stop command is output to the printer engine 19 and (Step 46) The fact that a band bitmap error has occurred is displayed on the display provided on the operation panel 15 (Step 47), and the current parallel processing ends.

At step 46, the printer engine 19
When a print stop command is output to the printer engine 19, printing is not performed until a print start command is output to the printer engine 19 based on the print data of the next page (see step 16).

The processing of FIG. 8 may be performed by hardware using a preset counter or the like.

When the full bitmap mode is selected, one page of bitmap data developed in the full bitmap development area E1 in step 5 is transferred to the printer engine 19 via the registers 17 and 18 by the DMA. Will be transferred.

[0063]

According to the present invention, occurrence of a bitmap error can be detected. Therefore, when a bitmap error occurs, it is possible to notify the fact or stop the printing operation.

[Brief description of the drawings]

FIG. 1 is an electric block diagram illustrating a configuration of a printer.

FIG. 2 is a flowchart showing a character descriptor table creation processing procedure by a CPU 10 according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a first example of the present invention, which is performed at the start of a printing operation when a band bitmap mode is selected.
9 is a flowchart illustrating a bitmap expansion processing procedure by the CPU 10 according to the embodiment.

FIG. 4 is a flowchart showing an interrupt processing procedure of the CPU according to the first embodiment of the present invention, which is performed when a transfer end signal is transmitted from the DMA controller 16 to the CPU 10 when the band bitmap mode is selected; It is.

FIG. 5 is a flowchart showing a character descriptor table creation processing procedure by a CPU 10 according to a second embodiment of the present invention.

FIG. 6 shows a second embodiment of the present invention which is performed at the start of a printing operation when the band bitmap mode is selected.
9 is a flowchart illustrating a bitmap expansion processing procedure by the CPU 10 according to the embodiment.

FIG. 7 is a flowchart showing an interrupt processing procedure of the CPU according to the second embodiment of the present invention, which is performed when a transfer end signal is sent from the DMA controller to the CPU when the band bitmap mode is selected; It is.

FIG. 8 is a flowchart showing parallel processing by the CPU 10 according to the second embodiment of the present invention, which is performed every time bitmap development is started when the band bitmap mode is selected.

[Explanation of symbols]

 10 CPU 12 Program ROM 13 Font ROM 14 RAM 16 DMA Controller 19 Printer Engine

 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-2-20358 (JP, A) JP-A-2-50852 (JP, A) JP-A-2-43066 (JP, A) JP-A-2- 157926 (JP, A) JP-A-2-112968 (JP, A) JP-A-1-141763 (JP, A) JP-A-1-139267 (JP, A)

Claims (4)

(57) [Claims] 1. A printing apparatus comprising: two bitmap storage units having the same capacity; and the bitmap storage unit alternately develops a bitmap for a required printing range into these bitmap storage units. In a printer that adopts a band map memory system that transfers bit map data to the engine, timing starts each time bit map development of print data for the required print range starts, and when the bit map development ends. A band bitmap error has occurred when the timer means to be reset and the time counted by the timer means have reached a predetermined reference time required to transfer bitmap data for the required print range. A printer comprising means for detecting 2. The printer according to claim 1, further comprising: a notifying unit for notifying that a band bitmap error has occurred when it is detected that a band bitmap error has occurred. 3. The printer according to claim 1, further comprising means for stopping a printing operation when it is detected that a band bitmap error has occurred. 4. A notifying means for notifying that a band bitmap error has occurred when it is detected that a band bitmap error has occurred, and performing a printing operation when it is detected that a band bitmap error has occurred. 2. The printer according to claim 1, further comprising means for canceling.