JP4753532B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a printer or a facsimile apparatus that receives image data transmitted from a host device such as a host computer.
[0002]
[Prior art]
Some conventional image forming apparatuses such as printers and facsimile machines are provided with a reception buffer in order to shorten the data transmission release time of a host computer which is a host device. Most image forming apparatuses having the reception buffer use a reception interrupt function, and take in data received from the host computer into the reception buffer. Then, as background processing, development processing is performed in which 1 byte of data stored in the reception buffer is read out, edited into a format that can be actually printed, and stored in the image buffer. Such control for storing the data received from the host computer in the reception buffer and then reading the data from the reception buffer and editing it into a printable format is performed without distinction between character data and image data.
[0003]
In the reception buffer control, it is necessary to perform RAM access processing such as update of the reception position of the reception buffer and update of the reading position. In the reception interrupt process, it is necessary to save and restore the register every time the operation starts and ends.
[0004]
[Patent Document 1]
JP-A-5-56106
[0005]
[Problems to be solved by the invention]
In the conventional image forming apparatus described above, a series of control (development processing) relating to data reception is performed without distinction between character data and image data. However, the image formation apparatus is composed of image data that is already developed bit images. Since the print pattern does not require character image generation and various modification processes like character data, the data read from the reception buffer is directly stored in the image buffer. Store Just do it. Therefore, there is no point in temporarily storing the data received from the host computer in the reception buffer, and conversely, the extra processing at the time of fetching into and reading out from the reception buffer increases the reception processing time. The burden has increased.
[0006]
Some host computers perform data transmission at intervals of several tens of milliseconds (millisecond). Such host computers have a period during which data transmission is not performed. Storage processing Since this is continued, the reception buffer immediately becomes empty during this period. Even in such a state, it is necessary to perform reception interrupt processing, fetching into the reception buffer, and reading processing, which is very inefficient control.
[0007]
In particular, in an image forming apparatus having a low-speed processing capacity microprocessor, when printing a print pattern composed of image data, the amount of data is enormous compared to character data. When the reception processing time for one line exceeds the mechanical printing operation time for one line due to an increase in the load of the reception process, a time for waiting for the completion of the reception process occurs between the lines, and the total throughput is lowered.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the solution means provided in the present invention is to receive received data consisting of character data or image data which is a bit image transmitted from a host device. At first In an image forming apparatus that stores data in a reception buffer, reads out reception data in the reception buffer, stores the data in the image buffer, and performs print processing, a reception circuit unit that receives the reception data from the host device, and the reception circuit unit When the received data is received, an interrupt process is generated, and the received interrupt control unit that stores the received data read from the receiving circuit unit by the interrupt process in the reception buffer, and the detection of the received data performed at a predetermined interval, Received image data And a background control unit that stores the image in the image buffer, and the background control unit is notified from the host device. amount of data If reception of image data is not completed and the image data is stored in the reception buffer, the image data is read from the reception buffer and stored in the image buffer, and the image is stored in the reception buffer. When no data is stored, the reception interrupt control unit is prohibited from generating an interrupt process, Until reception of the image data of the amount of data notified from the host device is completed From the receiver circuit section Remaining Read image data Without going through the receive buffer Stored in the image buffer and notified from the host device amount of data When the reception of the image data ends, the reception interrupt control unit restarts the generation of the interrupt process.
[0009]
In order to solve the above problem, another solution provided in the present invention is to receive received data consisting of character data or image data that is a bit image transmitted from a host device. At first In an image forming apparatus that stores data in a reception buffer, reads out reception data in the reception buffer, stores the data in the image buffer, and performs print processing, a reception circuit unit that receives the reception data from the host device, and the reception circuit unit When the received data is received, an interrupt process is generated, and the received interrupt control unit that stores the received data read from the receiving circuit unit by the interrupt process in the reception buffer, and the detection of the received data performed at a predetermined interval, Received image data And a background control unit that stores the image in the image buffer. The background control unit is notified from the host device. amount of data When the reception of the image data is not completed, the data amount of the image data stored in the reception buffer and the host device Informed The amount of image data stored in the reception buffer is compared with the amount of image data. Informed If the amount of image data is less than the amount of image data, the reception interrupt control unit is prohibited from generating an interrupt process, and the image data stored in the reception buffer is read and stored in the image buffer. Until reception of the image data of the amount of data notified from the host device is completed From the receiver circuit section Remaining Read image data Without going through the receive buffer Store in the image buffer and from the host device The amount of data notified When the reception of the image data ends, the reception interrupt control unit restarts the generation of the interrupt processing, and the amount of image data stored in the reception buffer is Informed If the amount of image data is greater than or equal to the image data, the image data is read from the reception buffer and stored in the image buffer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element common to each drawing.
[0011]
(First embodiment)
A configuration of an image forming apparatus such as a printer or a facsimile apparatus will be described. Figure 1 is the first
2 is a block diagram illustrating a control system of the image forming apparatus according to the first embodiment. FIG.
[0012]
In FIG. 1, an image forming apparatus (not shown) is provided with a reception circuit unit 11, a reception interrupt control unit 13, a background control unit 14, and a RAM 12. The reception circuit unit 11 latches data transmitted from the host computer 23 which is a host device, and generates a reception interrupt function at the reception timing. Note that this reception interrupt function has a circuit configuration capable of prohibiting and canceling the interrupt function according to an instruction from the background control unit 14.
[0013]
The RAM 12 includes a reception buffer 15 that temporarily stores data received by the reception circuit unit 11 and an image buffer 16 that stores reception data edited in a format that can be actually printed.
[0014]
The reception interrupt control unit 13 includes a reception buffer generation unit 17 and stores data received from the host computer in the reception buffer 15 of the RAM 12.
[0015]
The background control unit 14 includes an image buffer generation unit 22, a reception buffer reading unit 18, a print data analysis unit 19, a reception buffer storage number analysis unit 20, and a reception interrupt selection unit 21.
[0016]
The reception buffer reading unit 18 reads data in the reception buffer 15 of the RAM 12 and determines whether the print data received by the print data analysis unit 19 is character data or image data. The reception buffer storage number analysis unit 20 manages the number of data stored in the reception buffer 15. The reception interrupt selection unit 21 selects prohibition and cancellation of the reception interrupt function, and instructs the reception circuit unit 11. The image buffer generating unit 22 converts the image data received from the host computer 23 via the receiving circuit unit 11 or the image data received from the receiving buffer 15 into a format that can be actually printed. Without editing And stored in the image buffer 16.
[0017]
Such a background control unit 14 reads one byte of data in the reception buffer 15 of the RAM 12 in the reception buffer reading unit 18 and whether the data read in the print data analysis unit 19 is character data or image data. If it is determined that the data is character data, it is edited into an actually printable format and stored in the image buffer 16, and if it is determined that the data is image data, it is stored in the image buffer as it is. Perform image data expansion processing.
[0018]
The reception interrupt control unit 13 and the background control unit 14 constitute a microprocessor.
[0019]
Next, the operation at the time of data reception of the image forming apparatus having the above configuration will be described with reference to FIG. 1 and the flowcharts shown in FIGS. FIG. 2 is a flowchart showing the operation of the reception interrupt control unit of the first embodiment, and FIG. 3 is a flowchart showing image data expansion processing of the background control unit of the first embodiment.
[0020]
In FIG. 1, when receiving circuit unit 11 receives data from host computer 23, it latches the data and generates a reception interrupt at the received timing. Then, the reception buffer generation unit 17 of the reception interrupt control unit 13 starts its operation when this reception interrupt occurs. Hereinafter, the operation of the reception buffer generation unit 17 will be described with reference to the flowchart shown in FIG.
[0021]
In response to the occurrence of the reception interrupt described above, the reception buffer generation unit 17 saves the registers in step S1 and prepares to start reception interrupt processing. In step S <b> 2, the reception buffer generation unit 17 updates the reception buffer capture position in order to capture the received data into the reception buffer 15.
[0022]
In step S <b> 3, the reception buffer generation unit 17 stores the received data in the reception buffer 15. When data is stored in the reception buffer 15, a counter that manages the number of data stored in the reception buffer 15 is incremented. On the other hand, when reading data from the reception buffer 15, the counter is decremented.
[0023]
In step S3, the reception buffer generation unit 17 ends the reception interrupt processing when the received data is stored in the reception buffer 15, and restores the registers saved in step S4 in order to return to the control of the background control unit 14.
[0024]
Next, the operation of the background control unit 14 will be described. When the image forming apparatus receives data from the host computer 23 and the data is stored in the reception buffer 15, the background control unit 14 reads out one byte of data in the reception buffer 15 of the RAM 12 in the reception buffer reading unit 18. It is determined whether the data read by the print data analysis unit 19 is character data or image data. If it is determined that the data is character data, the image buffer generation unit 22 converts the data into a format that can be actually printed. When image development processing is performed for editing and it is determined that the data is image data, the data is stored in the image buffer as it is.
[0025]
Hereinafter, the image data development process of the background control unit 14 will be described with reference to FIG. 1 and the flowchart shown in FIG.
[0026]
In step S11, the background control unit 14 determines whether or not the number of image data stored in the reception buffer 15 of the RAM 12 is zero in the reception buffer storage number analysis unit 20, and the data is stored in the reception buffer 15. If it is determined that the stored number is zero, the process proceeds to step S16 if it is determined that the stored number is zero. At this time, since the image data is stored in the reception buffer 15 by the operation of the flowchart shown in FIG. 2, the process always proceeds from step S11 to step S12 when the flowchart shown in FIG. 3 is started.
[0027]
In step S12, the background control unit 14 updates the reading position in order to read out the image data in the reception buffer 15. In step S13, the background control unit 14 in the reception buffer reading unit 18 in the reception buffer 15 of the RAM 12 Read 1 byte of image data. At this time, the counter for managing the number of data stored in the reception buffer 15 is decremented.
[0028]
In step S14, the background control unit 14 converts the image data read from the reception buffer 15 into a format that can be actually printed by the image buffer generation unit 22. Without editing The image data is stored in the image buffer 16 of the RAM 12, and in step S15, the background control unit 14 determines whether or not all the image data for one data length has been stored in the image buffer 16. If it is determined that the storage has been completed, the process ends. If “NO”, the process from step S11 to step S15 is repeated.
[0029]
The host computer 23 declares the number of bytes, which is the amount of image data, and starts transmission to the receiving circuit unit 11. The data length in step S15 is defined at the beginning of the command (from the host computer 23). The total number of bytes of image data (all sequences of image data), and even if the processing from step S11 to step S15 is performed once, it is still transmitted from the host computer 23 in one transmission operation. There is still image data to come, Storage processing to image buffer 16 Is not finished (yet Storage processing to image buffer 16 If there is image data that has not been Storage processing to image buffer 16 Therefore, the process returns to step S11 again.
[0030]
Further, during the processing from step S11 to step S15, the next image data may be transmitted from the host computer 23 to the receiving circuit unit 11. In this case, when the process returns from step S15 to step S11, the number of image data stored in the reception buffer 15 is 1 or more, so the processing from step S12 to step S15 is performed again.
[0031]
When the host computer 23 performs data transmission at intervals of several tens of milliseconds (millisecond), the data in the reception buffer 15 is transmitted during a period in which no image data is transmitted from the host computer 23. Storage processing to image buffer 16 (Processing from step S11 to step S15) ends, and image data may be lost in the reception buffer 15. As described above, when the data length still remains but the image data in the reception buffer 15 is lost while the steps from S11 to S15 are repeated (the process returns from step S15 to step S11, and the image of the reception buffer 15 at this time). (When the number of stored data is zero).
[0032]
In this case, since the reception buffer storage number analysis unit 20 determines in step S11 that the image data in the reception buffer 15 is zero, the process proceeds to step S16. In step S <b> 16, the background control unit 14 sets reception interrupt prohibition in order to stop the reception interrupt function, that is, the operation of the reception interrupt control unit 13. Explaining this processing, when the reception buffer storage number analysis unit 20 determines that the number of data stored in the reception buffer 15 is zero, the reception interrupt selection unit 21 prohibits the reception circuit unit 11 from receiving interrupts. It is an instruction. Then, the reception circuit unit 11 operates so as to only latch received data without generating a subsequent reception interrupt in response to this instruction. In other words, received data is not received by a reception interrupt, but is received by detection of received data performed at a predetermined interval. The Note that when the reception interrupt selection unit 21 instructs the reception circuit unit 11 to cancel the reception interrupt prohibition, the reception circuit unit 11 receives data and the generation of the reception interrupt is resumed.
[0033]
When the above processing is performed and the process proceeds to step S17, the background control unit 14 determines whether there is reception data latched in the reception circuit unit 11, and if the image data is not yet latched, the reception circuit The unit 11 receives the image data and waits for the received data to be latched. On the other hand, when the image data is latched in the receiving circuit unit 11 or when the receiving data is latched in the receiving circuit unit 11, the process proceeds to step S <b> 18 and the background control unit 14 is latched from the receiving circuit unit 11. Read data. In step S19, the background control unit 14 converts the image data read from the reception circuit unit 11 into a format that can be actually printed by the image buffer generation unit 22. Without editing The image data is stored in the image buffer 16 of the RAM 12, and in step S20, the background control unit 14 determines whether or not all the data length of the image data can be stored in the image buffer 16. This data length is the data length described in step S15. If it is determined that the storage has been completed, the process proceeds to step S21. On the other hand, if “NO”, the processes from step S17 to step S20 are repeated.
[0034]
When the process proceeds from step S20 to step S21, the reception interrupt selection unit 21 instructs the reception circuit unit 11 to cancel the reception interrupt prohibition in order to restart the reception interrupt function, that is, the reception interrupt control unit 13. Thereby, when the reception circuit unit 11 receives data, a reception interrupt occurs.
[0035]
As described above, in the first embodiment, when the host computer 23 performs data transmission at intervals of several tens of milliseconds (millisecond), during a period in which data is not transmitted from the host computer 23, Of the image data in the reception buffer 15 Store to image buffer 16 May end, and there may be no data in the reception buffer 15. In such a case, in the present embodiment, the reception interrupt control unit 13 does not operate after that, and neither the process of fetching data into the reception buffer 15 nor the process of reading data from the reception buffer 15 is performed. The burden on the microprocessor when receiving image data can be reduced, and the reduction in throughput can be prevented. As a result, it is possible to improve the efficiency of subsequent image data reception and to obtain the maximum throughput.
[0036]
For character data, the reception interrupt function is used to collectively store the received character data in a reception buffer, which is then printed while performing character image generation and various modification processes, whereby data transmission of the host computer 23 is performed. The opening time can be shortened, and the transmission load on the image forming apparatus can be reduced.
[0037]
(Second Embodiment)
Next, a second embodiment will be described. In the image forming apparatus according to the second embodiment, the background control unit 14 performs image data Store to image buffer 16 Before starting, it is determined whether the image data for one data length scheduled to be transmitted from the host computer 23 is already stored in the reception buffer 15, and all the image data for one data length are still received in the reception buffer. If it is determined that the received interrupt function is not stored, the reception interrupt function thereafter, that is, the control for setting the reception interrupt inhibition to stop the operation of the reception interrupt control unit 13 is performed.
[0038]
That is, in the second embodiment, the image data Storage processing to image buffer 16 Before the image data Storage processing to image buffer 16 The purpose is to speed up the reception process when it is predicted in advance that there will be no stored data in the reception buffer 15.
[0039]
Since the configuration is the same as that of the first embodiment, description thereof is omitted.
[0040]
Next, an operation at the time of data reception of the image forming apparatus having the above configuration will be described. In the second embodiment, the operation of the reception interrupt control unit 13 is the same as that in the first embodiment, and thus the description thereof is omitted. Only the operation of the background control unit 14 will be described.
[0041]
When the image forming apparatus receives data from the host computer 23 and the received data is stored in the reception buffer 15, the background control unit 14 reads out 1 byte of data in the reception buffer 15 of the RAM 12 in the reception buffer reading unit 18. The print data analysis unit 19 determines whether the data read out is character data or image data. If it is determined that the data is image data, the image buffer generation unit 22 To store image data in the image buffer 16 I do.
[0042]
Hereinafter, the background control unit 14 Processing for storing image data in the image buffer 16 1 will be described with reference to the flowchart shown in FIG. FIG. 4 shows the background control unit of the second embodiment. Processing for storing image data in the image buffer 16 It is a flowchart which shows.
[0043]
In step S31, the background control unit 14 Processing for storing image data in the image buffer 16 Prior to this, the amount of image data (bytes) already stored in the reception buffer 15 and the data length (bytes) of the image data declared by the host computer 23 before the image data is transmitted from the host computer 23. Number). Here, if the number of bytes of image data already stored in the reception buffer 15 is equal to or greater than the total number of bytes of image data declared by the host computer 23 (the image data for one data length has already been received. If the number of bytes of image data currently stored in the reception buffer 15 is less than the total number of bytes of one data length, the process proceeds to step S32. ) Proceed to step S36.
[0044]
In the determination of step S31, Processing for storing image data in the image buffer 16 If it is determined that the image data for one data length has already been stored in the reception buffer 15 before starting the operation, and the process proceeds to step S32, the background control unit 14 reads out one byte of the image data in the reception buffer 15. In step S33, the reception buffer reading unit 18 reads out one byte of image data in the reception buffer 15 of the RAM 12. At this time, the counter for managing the number of data stored in the reception buffer 15 is decremented.
[0045]
In step S34, the background control unit 14 converts the image data read from the reception buffer 15 into a format that can be actually printed by the image buffer generation unit 22. Without editing The image data is stored in the image buffer 16 of the RAM 12, and in step S35, the background control unit 14 determines whether or not all the image data for one data length has been stored in the image buffer 16. If it is determined that the storage has been completed, the process ends. If “NO”, the process from step S32 to step S35 is repeated.
[0046]
When the process proceeds from step S31 to step S32 as described above, Storage processing to image buffer 16 Since all the image data for one data length has already been stored in the reception buffer 15 before the start of the process, one byte of image data is read from the reception buffer 15, Storage processing to image buffer 16 Is repeated for one data length.
[0047]
Next, a case where the process proceeds from step S31 to step S36 will be described. In step S <b> 36, the background control unit 14 sets reception interrupt prohibition in order to stop the reception interrupt function, that is, the operation of the reception interrupt control unit 13. Explaining this processing, the reception interrupt selection unit 21 of the background control unit 14 instructs the reception circuit unit 11 to prohibit reception interrupts. Then, the reception circuit unit 11 operates so as to only latch received data without generating a subsequent reception interrupt in response to this instruction. Note that when the reception interrupt selection unit 21 instructs the reception circuit unit 11 to cancel the reception interrupt prohibition, the reception circuit unit 11 receives data and the generation of the reception interrupt is resumed.
[0048]
Next, in step S37, the background control unit 14 determines whether or not the number of image data in the reception buffer 15 of the RAM 12 is zero in the reception buffer storage number analysis unit 20, and the image data is stored in the reception buffer 15. If it is determined that the number of stored images is zero, the process proceeds to step S43. Since the image data is stored in the reception buffer 15 by the operation of the flowchart shown in FIG. 2, the image data is always stored in the reception buffer 15 at the time of step S37. Accordingly, the process proceeds from step S37 to step S38.
[0049]
In step S38, the background control unit 14 updates the reading position in order to read data in the reception buffer 15. In step S39, the background control unit 14 in the reception buffer reading unit 19 images in the reception buffer 15 of the RAM 12. Read 1 byte of data. At this time, the counter for managing the number of data stored in the reception buffer 15 is decremented.
[0050]
In step S40, the background control unit 14 converts the image data read from the reception buffer 15 into a format that can be actually printed by the image buffer generation unit 22. Without editing The image data is stored in the image buffer 16 of the RAM 12, and in step S41, the background control unit 14 determines whether or not all the image data for one data length has been stored in the image buffer 16. If it is determined that the storage has been completed, the process proceeds to step S42. If “NO”, the process returns to step S37. And all the data in the receive buffer 15 Processing for storing image data in the image buffer 16 Steps S37 to S41 are repeated until is completed.
[0051]
When the process proceeds from step S41 to step S42, the reception interrupt selection unit 21 instructs the reception circuit unit 11 to cancel the reception interrupt prohibition in order to restart the reception interrupt function, that is, the reception interrupt control unit 13. Thereby, when the reception circuit unit 11 receives data, a reception interrupt occurs.
[0052]
In steps S38 to S41, the reception interrupt function is prohibited and the operation of the reception interrupt control unit 13 is stopped. Then, all the image data stored in the reception buffer 15 is read out and stored in the image buffer 16. The operation of storing is performed.
[0053]
It should be noted that image data may be transmitted from the host computer 23 while the processing from step S37 to step S41 is repeated. In this case, the background control unit 14 receives the image data from the host computer 23. Control not to receive. By doing this Processing for storing image data in the image buffer 16 By giving priority to the processing, the processing speed of the microprocessor can be increased.
[0054]
Next, still all of the image data Storage processing to the image buffer 16 for the data length A case will be described in which it is determined that the data in the reception buffer 15 has run out before the process ends. This is a case where the process proceeds from step S37 to step S43. When the process proceeds to step S43, the background control unit 14 determines whether there is reception data latched in the reception circuit unit 11, and the reception data is latched. If not, the receiving circuit unit 11 receives the data and waits for the received data to be latched. On the other hand, when the reception data is latched in the reception circuit unit 11, the process proceeds to step S44, and the background control unit 14 reads the latched data from the reception circuit unit 11.
[0055]
In step S45, the background control unit 14 converts the image data read from the reception circuit unit 11 into a format that can be actually printed by the image buffer generation unit 22. Without editing The image data is stored in the image buffer 16 of the RAM 12, and in step S41, the background control unit 14 determines whether or not all the data length of the image data can be stored in the image buffer 16. If it is determined that the storage has been completed, the process proceeds to step S42. On the other hand, if “NO”, the processes of step S37, step S43, step S44, step S45, and step S41 are repeated.
[0056]
When the process proceeds from step S41 to step S42, the reception interrupt selection unit 21 instructs the reception circuit unit 11 to cancel the reception interrupt prohibition in order to restart the reception interrupt function, that is, the reception interrupt control unit 13. Thereby, when the reception circuit unit 11 receives data, a reception interrupt occurs.
[0057]
As described above, in the second embodiment, Store image data in image buffer 16 Before starting, the amount of image data already stored in the reception buffer 15 (the number of stored image data) and all of the image data declared by the host computer 23 before the image data is transmitted from the host computer 23. The data amount (image data data length) is compared, and if the data amount of the image data already stored in the reception buffer 15 is less than the total data amount of one data length, the reception interrupt control unit 13 is not operated. In addition, since the process of fetching data into the reception buffer 15 and the process of reading data from the reception buffer 15 are not performed, the burden on the microprocessor when receiving image data is reduced, and a decrease in throughput can be prevented. it can. As a result, it is possible to improve the efficiency of image data reception and obtain the maximum throughput.
[0058]
In the first embodiment, image data reception and Storage processing to image buffer 16 In the second embodiment, while switching to high-speed reception processing while performing Store image data in image buffer 16 Prior to Processing for storing image data in the image buffer 16 When it is expected that there will be no image data stored in the reception buffer 15, it is possible to switch to high-speed reception processing.
[0059]
Further, in the second embodiment, it is possible to improve the efficiency of image data reception when the host computer 23 continuously transmits data or when the print pattern has a large data length.
[0060]
For character data, the reception interrupt function is used to collectively store the received character data in a reception buffer, which is then printed while performing character image generation and various modification processes, whereby data transmission of the host computer 23 is performed. The opening time can be shortened, and the transmission load on the image forming apparatus can be reduced.
[0061]
【The invention's effect】
As described above in detail, according to the present invention, print data Storage processing to image buffer 16 When storing image data in the reception buffer, all print data in the reception buffer Storage processing to image buffer 16 If print data is not stored in the reception buffer, the image data transmitted from the host device is not stored in the reception buffer. Storage processing to image buffer 16 It is possible to obtain the maximum throughput by directly storing in the image buffer.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a control system of an image forming apparatus according to a first embodiment.
FIG. 2 is a flowchart illustrating an operation of a reception interrupt control unit according to the first embodiment.
FIG. 3 shows a background control unit according to the first embodiment. Processing for storing image data in the image buffer 16 It is a flowchart which shows.
FIG. 4 shows a background control unit according to the second embodiment. Processing for storing image data in the image buffer 16 It is a flowchart which shows.
[Explanation of symbols]
14 Background control unit
15 Receive buffer
16 Image buffer
23 Host computer

Claims (2)

First it received data consisting of image data is a character data or bit image transmitted from the host apparatus is stored in the reception buffer, reads out the received data in the receive buffer and the print processing is stored in the image buffer In the image forming apparatus,
A receiving circuit unit that receives received data from the host device;
When receiving data is received by the receiving circuit unit, an interrupt process is generated, and a receiving interrupt control unit that stores the received data read from the receiving circuit unit by the interrupt process in the receiving buffer;
A background control unit that reads out received image data and stores the received image data in the image buffer by detection of received data performed at a predetermined interval;
When the image data is stored in the reception buffer when the reception of the image data of the data amount notified from the host device is not completed, the background control unit receives the image data from the reception buffer. Is stored in the image buffer,
When image data is not stored in the reception buffer, the reception interrupt control unit is prohibited from generating an interrupt process, and the reception of the image data of the amount of data notified from the host device is completed. The remaining image data is read from the receiving circuit unit, stored in the image buffer without passing through the receiving buffer, and when reception of the image data of the amount of data notified from the host device is completed, the reception interrupt control unit An image forming apparatus that restarts generation of interrupt processing. First it received data consisting of image data is a character data or bit image transmitted from the host apparatus is stored in the reception buffer, reads out the received data in the receive buffer and the print processing is stored in the image buffer In the image forming apparatus,
A receiving circuit unit that receives received data from the host device;
When receiving data is received by the receiving circuit unit, an interrupt process is generated, and a receiving interrupt control unit that stores the received data read from the receiving circuit unit by the interrupt process in the receiving buffer;
A background control unit that reads out received image data and stores the received image data in the image buffer by detection of received data performed at a predetermined interval;
The background control unit is notified of the data amount of the image data stored in the reception buffer and the host device when reception of the image data of the data amount notified from the host device is not completed. If the amount of image data stored in the reception buffer is less than the amount of image data notified from the host device, the reception interrupt control unit The generation of interrupt processing is prohibited, the image data stored in the reception buffer is read out and stored in the image buffer, and then the reception of the image data of the data amount notified from the host device is completed. above without going through the reception buffer read the rest of the image data from the receiving circuit section Imejiba Storing the file, when the reception of the image data of notified data amount from the host device is completed, to resume the generation of the interrupt process on the receive interrupt control unit,
If the amount of image data stored in the reception buffer is greater than or equal to the amount of image data notified from the host device, the image data is read from the reception buffer and stored in the image buffer. An image forming apparatus.

Images