WO2006054618A1

WO2006054618A1 - Method and device for transferring data to peripheral device

Info

Publication number: WO2006054618A1
Application number: PCT/JP2005/021086
Authority: WO
Inventors: Tomokazu Nagai
Original assignee: Naltec Inc.
Priority date: 2004-11-17
Filing date: 2005-11-17
Publication date: 2006-05-26
Also published as: JPWO2006054618A1

Abstract

A host device (2) has a transfer function (22) for dividing output data into a plurality of sets of transfer data and transferring them to a peripheral device (3). The transfer function (22) provides a device for successively compressing the plurality of sets of transfer data, storing them in a memory (14), selecting a compressed data set (82c) and a non-compressed data set (82n), and transferring them. The transfer function (22) makes judgments including the following judgments. When a current data set transfer can be started and if the current data set has been compressed, the compressed data set is transferred. If the current data set has not be compressed, the first end time when the compressed data set is transferred and the second end time when the non-compressed data set is transferred are predicted and the data set having the shorter end time predicted is transferred. If the next data set compression is not started when transfer is started, the compression of the data set is started.

Description

Specification

Method and apparatus for transferring data to a peripheral device

Technical field

[0001] The present invention relates to a control method and apparatus including a process of transferring data to a peripheral device.

Background art

[0002] Systems for compressing and transmitting (transmitting) image data are known. An example is a system that outputs compressed data from a host device to a printer and decompresses the data with the printer. Japanese Patent Laid-Open No. 2001-53619 discloses an image data communication apparatus that determines the type of data compression processing and data compression ratio parameters in a transmission-side apparatus based on the communication speed. In this image data communication device, the communication time between the transmission side device and the reception side device is measured using the test data, the communication speed is calculated from the communication time and the data size of the test data, and the compression is performed based on the communication speed. Determine the parameters.

[0003] In a system in which image data is compressed and transmitted by a sending device such as a host device, the entire image data is divided into unit data sets that are processed by peripheral devices such as printers and display devices, and transferred in order. To do. When transferring data with compression, if there are hardware and software resources that can process compression processing and transfer processing in parallel, compression of one divided transfer data is completed, and subsequent data sets For, it is possible to send a compressed data set while continuing the compression process. If the peripheral device generates output in units of 1 line, 1 page or 1 frame, for example, prints or displays images, the compressed data set in that unit is also used by the host device as a peripheral device. It is possible to transfer sequentially. Peripherals can generate the output intended by the host device by appropriately converting and reconfiguring the transferred data. Since the transfer time is reduced for compressed transfer data, generally the processing time of the entire job for transferring the data from the host to a peripheral device such as a printer can be reduced.

[0004] However, it takes time to compress the host device. Therefore, pressure If the reduction time becomes a critical path for the processing speed of the output job using the peripheral device, it is possible that the processing time of the entire job can be shortened by transferring the data without compression. On the other hand, if the transfer time becomes a critical path, it is desirable to send compressed transfer data. In Japanese Unexamined Patent Publication No. 2001-53619, the compression parameter is determined at the start of a job.

However, it is not determined whether it is preferable to transfer compressed data uniformly at the start of a job. For example, the time required for compression and the data transfer time do not depend only on the amount of data. The time required for compression also depends on the compression method, the type of data, and the host CPU occupancy rate. In addition, the amount of data after compression is not always constant, which affects the transfer time. In addition, the transfer time depends not only on the transfer speed (communication speed) but also on the time and timing for releasing the buffer in the peripheral device. In addition, during the job, the transfer data is sent in sequence, and the time required for compression and the transfer time can always vary during the job.

Disclosure of the invention

[0006] One aspect of the present invention is a peripheral device control method including a step of dividing output data from a host device into a plurality of sets of transfer data and transferring the data to the peripheral device. In this transfer step, a plurality of sets of transfer data are sequentially compressed and stored in a memory, and either a compressed data set or an uncompressed data set is selected and transferred. In addition, this transfer process is

If the current data set has already been compressed when the transfer of the current data set can be started, the compressed current data set is transferred,

If the current data set can be started and the current data set is not compressed, the first end time when the compressed current data set is transferred and the current uncompressed time Predict the second end time when the current data set is transferred, transfer the current data set with a shorter predicted end time,

When starting the transfer of the current data set, if the compression of the next data set has not been started, this includes starting the compression of the next data set. In addition, this specification The transfer data set is referred to as a set or a data set.

[0007] When transfer of the current data set (new data set) of transfer data can be started (when transfer can be started), the compression state of the current data set is determined. This makes it possible to control that the time required for compression continues to be a critical path of processing speed when some condition changes in the output job by the transferring process. In addition, the first and second end times are predicted when the transfer can be started. As a result, the data set that minimizes the total time required for the remaining compression and transfer can be selected each time.

[0008] Furthermore, when the transfer of the current data set is started (at the start of transfer), the compression of the next data set is forcibly started. As a result, the compression of the next data set is started immediately without waiting for the end of the compression of the current data set, and the time loss of the compression process can be suppressed. Furthermore, since the transfer of the first data set immediately after the output job is started is started without waiting for compression, there is a possibility that the time required for the first output of peripheral devices can be shortened.

[0009] The data transfer rate may vary during a job. Therefore, it is desirable that the transfer process includes predicting the first end time and the second end time based on the transfer rate of the previous data set. The transfer rate of the previous transfer data can be determined on the data processing device side based on a signal indicating that the reception from the peripheral device is completed, for example, a transfer permission signal. In order to reduce the possibility that the transfer time of the transfer permission signal is added as an error, it is desirable to measure the transfer speed by an appropriate method on the side of the peripheral device and send it to the data processing device together with the transfer permission signal. Preferably, the transferring step includes obtaining the transfer speed or information for determining the transfer speed together with the peripheral device power transfer permission signal.

[0010] In the transferring step, the first data set of the transfer data of the job is transferred in an uncompressed state. Therefore, since the transfer method of the next data set is selected depending on the transfer time of the first data set, it is possible to save time and processing time for transferring the test data.

[0011] At the start of transfer, the buffer capacity of the peripheral device allocated for data transfer is Greatly affects data transfer time. If the amount of data in the data set to be transferred is larger than the free capacity of the buffer and the buffer release speed is slower than the transfer speed, it is necessary to wait for the buffer to be released during the transfer. In general, since the buffer release rate is slower than the data transfer rate, the buffer release rate affects the data set transfer time.

[0012] For this reason, if the transfer process is larger than the free capacity of the buffer of the peripheral device assigned to the data transfer, the compressed data set is compressed. Hope to include transferring, and so on. In cases where the amount of data in the compressed data set exceeds the free space of the buffer, if the data set is uncompressed, the transfer speed may be determined depending on the release speed or waiting for the buffer free space multiple times. Is expensive. For this reason, the prediction accuracy of the second end time is greatly reduced. Therefore, it is desirable not to predict the end time and transfer the compressed data set.

[0013] In the transferring step, the predicted data amount of the compressed current data set is smaller than the free space of the peripheral device buffer and the data amount of the uncompressed current data set If it is greater than the free space, it should include predicting the second end time based on the previous data set transfer rate and buffer release rate. In this case, the accuracy of predicting the second end time can be improved by taking into account the release rate of the noffer. The release rate of the noffer is data that depends on the peripheral device, so it can be set in the host device in advance. Similarly to the transfer rate, the peripheral device can measure the release rate by an appropriate method and send it to the host device along with the transfer permission signal.

[0014] In this transfer step, a compressed data set or an uncompressed data set is selected according to the state that changes during the progress of the output job, not just the state when the output job is started. Can be transferred to. For this reason, the host device can also provide a method suitable for improving the processing speed of jobs that transfer and output data to peripheral devices (peripheral devices). The method of one embodiment of the present invention includes combinations with other optimization methods. For example, the transferring step may include setting an optimal compression method according to the initial conditions of the output job. In a host device that can operate in parallel the compression process or compression means by a plurality of different types of methods, Therefore, it is possible to further predict the end time of a data set compressed by different methods, select the current data set with the shortest end time, and select the optimal compression method from among these different methods at any time. It is also possible to include

[0015] Another aspect of the present invention is an apparatus having transfer means for dividing output data into a plurality of sets of transfer data and transferring the output data to a peripheral device so that the peripheral device can generate an output based on the output data. It is. This transfer means compresses a plurality of sets of transfer data in order and stores them in a memory, and selects and transfers either a compressed data set or an uncompressed data set.

[0016] The transfer means further includes:

If the current data set has already been compressed when it is possible to start transferring the current data set, transfer the compressed current data set.

If the current data set can be started and the current data set is not compressed, the first end time when the compressed current data set is transferred and the current uncompressed time Predicting the second end time when the data set is transferred, and transferring the current data set with a short predicted end time,

When the transfer of the current data set is started, if the next data set has not been compressed, a determination is made including starting the next data set.

[0017] It is desirable that the transfer means predicts the first end time and the second end time based on the transfer rate of the previous data set. For this reason, it is desirable that the judging means obtains the transfer speed or information for obtaining the transfer speed together with the peripheral device power transfer permission signal.

[0018] The transfer means transfers the compressed current data set when the predicted data amount of the compressed current data set is larger than the free space of the peripheral device buffer allocated for data transfer. It is desirable to make a judgment that includes

[0019] In addition, the transfer means is configured such that the compressed predicted data amount is smaller than the buffer capacity of the peripheral device and the uncompressed current data set data amount is smaller than the buffer free capacity. When it is large, it is desirable to predict the second end time based on the transfer rate of the previous data set and the buffer release rate. [0020] Another different aspect of the present invention is a system including a host device and a printer that performs printing based on the output data divided and transferred into a plurality of sets of transfer data of the host device. The host device has transfer means for compressing a plurality of sets of transfer data in order and storing them in a memory, and selecting and transferring either a compressed data set or an uncompressed data set. The transfer means is

[0021] The transfer means preferably predicts the first end time and the second end time based on the transfer rate of the previous data set. Alternatively, there is provided means for transmitting information for obtaining the transfer speed together with the transfer permission signal.

[0022] Another different aspect of the present invention is a device driver program for dividing output data from a computer into a plurality of sets of transfer data and transferring the data to a peripheral device, and generating an output based on the output data in the peripheral device. ! /, Is a device driver product. This device driver program includes a process of compressing a plurality of sets of transfer data in order and storing them in a computer memory, and selecting and transferring either a compressed data set or an uncompressed data set in the memory. .

[0023] This transfer process is:

If the current data set is not compressed, the first end time when the compressed current data set is transferred and the second end time when the uncompressed current data set is transferred. When the current data set with a short predicted end time is transferred and the transfer of the current data set is started, compression of the next data set is started. Initiating compression of the data set.

[0024] Preferably, the transferring process includes predicting the first end time and the second end time based on the transfer rate of the previous data set. In addition, it is preferable that the transfer process includes obtaining the transfer speed or information for obtaining the transfer speed from the peripheral device together with the transfer permission signal. In addition, the processing to be transferred is further predicted data capacity of the compressed current data set is larger than the free space of the peripheral buffer allocated for data transfer. It is desirable to include In addition, the process of transferring is further based on the fact that the predicted data volume of the compressed current data set is smaller than the free space of the peripheral buffer, and the data volume of the uncompressed current data set is smaller than the free space of the buffer. If large, it is desirable to include predicting the second end time based on the previous data set transfer rate and buffer release rate.

[0025] This device driver program or program product has instructions or codes that enable the above-described processing to be executed by a computer, and is recorded on a suitable recording medium such as a CD-ROM or the like. Can be provided via a network. By mounting or loading the device driver program on a computer, the method having the transferring step of the present invention can be executed by the computer. Also, by mounting or loading this device driver program on a computer, the computer can function as an apparatus having the transfer means of the present invention.

[0026] According to the present invention including these aspects, when data is transferred to a host-side peripheral device by dividing it into a plurality of sets of transfer data, the transfer time is minimized each time each data set is transferred. It is possible to select an expected data set. Therefore, it is possible to automatically reflect the situation that changes with the progress of the job in the transfer form, and it is possible to improve the processing speed of the job.

Brief Description of Drawings

[0027] [Fig. 1] Transferring computer power data as a host device using a printer as a peripheral device. The figure which shows the outline of the system which prints.

FIG. 2 is a diagram showing an outline of functions of a printer driver of a host device.

FIG. 3 is a flowchart showing an outline of processing by a printer driver.

FIG. 4 is a flowchart showing an outline of printer processing.

FIG. 5 is a timing chart showing the progress of a job for printing out an image.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows an outline of a system 1 in which a host computer and a printer are connected. The host computer 2 is installed with an operating system 11, application software 12 that operates on the operating system and performs image processing, and a printer driver 13. The host computer 2 transfers the image data 81 selected or generated by the application 12 to the printer 3 via the printer driver 13 and the communication path 4 formed by an interface cable or wirelessly. Based on the transferred image data 81, the printer 3 generates (prints) a printed material corresponding to the data 81.

The printer driver 13 divides the selected image data 81 into a plurality of sets of transfer data 82 in units of one or a plurality of lines, and transfers the transfer data sets 82 to the printer 3 in order. The printer 3 generates a printout corresponding to the image data 81 based on the transfer data set 82 transferred in order. Hereinafter, the transfer data set 82 is referred to as a set or a data set.

The printer driver 13 divides and acquires the image data 81 spooled in the RAM 14 of the host 2 or the memory 14 such as a hard disk into data sets 82 of appropriate units when a print event occurs, and the data This is a device driver program that transfers the set 82 to the printer 3 in order after being compressed or uncompressed. Accordingly, the printer driver 13 is installed in the computer 2 to realize a predetermined function using an appropriate resource of the computer 2. The printer driver 13 sequentially compresses the acquired data set 82, stores the compressed data set 82c (after compression) in the memory 14, and stores the compressed data set 82c, which is not compressed (before compression). ) Data set 82η is selected and transferred to printer 3.

[0031] The transfer function 22 is the data divided to transfer the image data 81 that is output data. One of the compression function 21 that compresses the set in order and stores it in the memory 14 and the compressed data set 82c and the uncompressed data set 82η stored in the memory 14 via the communication path 4 The selection function 24 for outputting to the printer 3 and the determination function 25 for determining the data set selected by the selection function 24 are provided. The judgment function 25 judges the condition or status at that time when the transfer of each data set 82 can be started (when the transfer can be started), and as the data set 82 to be transferred this time (current data set) 82, Select compressed data set 82c or uncompressed data set 82η.

[0032] The printer 3 includes a CPU 31, a RAM 32, a ROM 33, a decompression unit 34 for decompressing the compressed data set 82c, an interface 35 for exchanging data with the host device 2, and a printer engine 37. A mechanism control unit 36 for controlling and a bus 38 for connecting them are provided. The interface 35 acquires the compressed data set 82c or the uncompressed data set 82η transferred from the host device 2, and the data set is a buffer for data transfer secured in a partial area of the RAM 32. Store in 39. If the acquired data set 82 is compressed, it is decompressed by the decompression unit 34 and supplied to the mechanism control unit 36, and a printed matter is printed by the printing mechanism (engine) 37 based on the data set 82. If the acquired data set 82 is uncompressed, it is supplied to the mechanism control unit 36 without being expanded, and the printed matter 37 is printed by the printing mechanism 37 based on the data set 82. The printer 3 performs various controls based on a control program (firmware) 40 stored in advance in the CPU 31 power ROM 33. For example, the CPU 31 performs a process of controlling whether the data set 82 stored in the buffer 39 is compressed, whether the data set 82 is uncompressed data, and receiving data at the nother 39. Further, the CPU 31 can instruct to perform printing in units of the acquired data set 82, for example, in units of lines.

FIG. 2 shows a schematic configuration of the transfer function 22 included in the printer driver 13. The compression function 21 sequentially acquires uncompressed transfer data sets 82η from the image data 81, compresses them, and stores the compressed data sets 82c in the memory 14 in order. However, when the transfer start signal 88 is received from the judgment function 25, the compression of the next data set is started if the next data set scheduled to be transferred next to the current data set is not started. . That is, the compression function 21 transfers the data set 82η in the middle of compression. When the instruction 88 is received, the compression of the data set 82η is interrupted, and the compression of the next data set 82η is started. If the next data set compression is not started when the current data set transfer starts (at the start of the transfer), the decision to start the next data set compression may be included in the decision function 25. it can.

The determination function 25 includes a first determination function 41 and a second determination function 42. These determination functions 41 and 42 determine the state when the transfer can be started for each data set, and the type of the data set 82 output from the selection function 24 (whether it is compressed or uncompressed). Select. The first determination function 41 uses the selection function 24 to compress the memory 14 if the current data set 82 has already been compressed by the compression function 21 when the transfer of the current data set 82 to be newly started can be started. The current data set 82c already selected is selected, and an instruction is given to transfer the compressed current data set 82c to the printer 3.

[0035] If the data amount of the compressed data set 82c is compared with the data amount of the uncompressed data set 82η, the data amount of the compressed data set 82c is smaller. If the compressed data set 82c is already prepared when transfer can be started, the compressed data set is transferred because time is not required for compression. In this specification, “when transfer can be started” indicates the timing when the current data set 82 can be transferred. For example, if it is the first data set, it is the timing when a print event occurs in the host computer 2 and a print job is started. If it is in the middle of the job, it is the timing when the previously transferred data set 82 is stored in the buffer 39 of the printer 3 and the transfer permission signal 85 is notified from the printer 3 to the host computer 2. The reception completion notification notified from the printer 3 is the transfer permission signal 85.

The second determination function 42 determines when the current data set 82 has not been compressed by the compression function 21 when transfer can be started. That is, the second determination function 42 first determines that there is no compressed current data set 82c in the memory 14. Next, the second determination function 42 waits for the compression process of the current data set 82 to be completed, and then the first end time Tcp when the compressed data set 82c is transferred and the compression process. Without waiting for completion, predict the second end time Tnp when the uncompressed data set 82η is transferred. It then controls the selection function 24 to transfer the data set that is expected to end first. The In other words, the second decision function 42 selects and transfers the current data set 82c with the shortest predicted end time among the compressed current data set 82c and the uncompressed current data set 82η. Like that. If the data set is not compressed when transfer can be started, it is desirable that the total time of the remaining time required for compression and the time required for transfer is shorter. The second determination function 42 shortens the time required for the transfer process of the current data set 82 by predicting the first end time Tcp and the second end time Tnp.

[0037] The second determination function 42 further determines several cases based on the free capacity Nb of the data transfer buffer 39 secured in the printer 3 when the transfer can be started. It has a judgment function to transfer the optimal data set. Each parameter referenced below is the value obtained each time the data set is transferred unless otherwise indicated.

R: Transfer rate or transfer rate (actual data set transferred last time)

Nb: Free space in buffer 39 for data transfer of printer 3 when transfer can start

Nn: Data size or data of the current data set 82 (uncompressed data set 82c)

Ncf: Predicted data volume when the current data set 82 is compressed (predicted compressed data value) Tcf: Force at which transfer can be started Predicted remaining time until compression processing of the current data set 82 is completed (predicted remaining time of compression)

K: Release speed of printer 3 notifier 39 (constant or previous record)

Tcp: Predicted end time (first end time) when the compressed data set 82c is transferred

Tnp: Estimated end time (second end time) when uncompressed data set 82η is transferred

[0038] Case A (Nn <Nb)

In Case A, the free space Nb of the buffer 39 is larger than the data amount Nn of the current uncompressed data set. In this case, the first end time T cp and the second end time Tnp can be calculated by the following equations (1) and (2). Tcp = Tcf + Ncf / R (1)

Tnp = Nn / R (2)

In this case A, the current data set can be transferred to the buffer 39 on the printer side without any problem even if the compressed data set and the uncompressed data set are misaligned. Therefore, the data set with the shorter end times Tcp and Tnp is transferred.

[0040] Case Β (? ^^ <? ^) <? ^ 1, brackets, 1 ^ <1

The first condition in this case Β indicates that the free capacity of the buffer 39 Nb force is larger than the compressed data predicted value Ncf which is smaller than the data amount Nn of the current data set 82η uncompressed. Under this condition, if the release speed K of the notifier 39 is the same as or faster than the transfer speed R, the notifier will not become full. Therefore, the end time for compressed and uncompressed data sets can be calculated as in Case A.

[0041] The following condition for Case B indicates that the release speed K of the notifier 39 is slower than the transfer speed R. Therefore, when transferring an uncompressed data set, a notafull occurs.

[0042] First, in this case B, the first end time Tcp of the compressed data set 82c can be calculated by the equation (1) as in the case A. On the other hand, the second end time Τηρ of the uncompressed data set 82η can be calculated by the following equation (3) that takes into account the notafull. When the uncompressed data set 82η is transferred, it becomes noffer full, and after that it is transferred at the release rate 以降 and its end time Τηρ is predicted.

Tnp = Nb / R + (Nn-Nb) / K (3)

[0043] Case C (Nb <Ncf)

In case C, the free space Nb of the buffer 39 of the printer 3 when transfer can start is smaller than the predicted compressed data value Nc; f. Under this condition only, if the release speed K of the buffer 39 is equal to or faster than the transfer speed R, the buffer will not become full. Therefore, the end time for compressed and uncompressed datasets can be calculated as in case A

[0044] In case C, if the release rate K of the notifier 39 is slower than the transfer rate R (K <R), even if the compressed data set is transferred more than just the uncompressed data set, the buffer is transferred. A buffer full occurs. Therefore, in this case, considering buffer full, the first end time Tcp of the compressed data set 82c can be predicted by the following equation (4). The second end time Tnp of the uncompressed data set 82η can be obtained by the above equation (3) as in the case ケース.

Tcp = Tcf + Nb / R + (Ncf-Nb) / K (4)

[0045] In this case C, the compressed current data set 82c also becomes full during transfer in the same way as the uncompressed current data set 82η, and after that the first data set 82c is transferred at the release speed K. The end time of Tcp can be predicted. However, since the release speed K is slower than the transfer speed R, the ratio of the data transfer time to the estimated remaining compression time Tcf increases, and in most cases the first end time Tcp Is shorter. Further, since the accuracy of the release speed K that can be predicted on the host side is low, if the time determined by the release speed K increases, the prediction accuracy of the first end time Tcp and the second end time Tnp decreases. Therefore, in this example, if the second function 42 determines that it is case C, the second function 42 does not predict the end time, and the compression function 21 generates the compressed current data set 82c. Wait and control the selection function 24 to transfer the compressed data set 82c.

In this way, by calculating the first end time Tcp and the second end time T np by the second determination function 42 and selecting the transfer of the data set that ends first, Reduce the processing time required to transfer this dataset 82. The second determination function 42 determines the transfer rate R used for calculating the first end time Tcp and the second end time Tnp, the data size Nn of the previous data set 82 transferred immediately before, and the previous data. Calculated by dividing by the reception time Tt in printer 3 of set 82. The printer 3 transmits the reception time Tt as information for obtaining the transfer rate R together with the transfer permission signal 85 or the transfer rate R calculated based on the reception time Tt to the host 2. The printer driver 13 of the host 2 can acquire the latest transfer rate R each time the transfer of the current data set 82 can be started upon receiving the transfer permission signal 85. Therefore, when the end times Tcp and Tnp of the current data set 82 are predicted, the first end time Tcp and the second end time Tnp can be calculated based on the transfer rate R in the course of the job. Therefore, the data set is selected in consideration of the status change of the transfer path in the middle of the job and the transfer time is shortened. Can be planned.

The printer 3 transmits, together with the transfer permission signal 85, the free capacity Nb of the notifier 39 and the release rate K of the noffer when the previous data set is processed. By receiving these, the printer driver 13 on the host side can determine the above cases A to C when the transfer can be started, and more accurate first end time Tcp and second end time. Tnp can be calculated. This makes it possible to shorten the transfer time by selecting a data set in consideration of printer status changes during the job.

[0048] The transfer speed R, the free space Nb, and the release speed K are determined by the printer driver 13 based on the job progress status if information such as the printer model and the communication path with the printer is set in the printer driver 13 in advance. You can make your own predictions. By obtaining the actual values from the printer 3, the reliability of the prediction can be improved, and the calculation load of the printer driver 13 can be reduced.

[0049] As shown in FIG. 2, the control function realized by the firmware 40 in the printer 3 of this example is the time Tt required to receive each data set 82, the release speed K of the buffer 39, and the A function 46 for notifying the free side Nb to the host side together with the transfer permission signal 85 is provided. This control function 40 also has a function 45 for determining whether the data set 82 stored in the nother 39 is compressed or uncompressed. The control function 40 is supplied to the function 34 for expanding the data set 82 stored in the nother 39. Or supply the mechanism control 36 by bypassing the expanding function 34.

[0050] Generally, the release speed K of the noffer 39 changes in proportion to the compression rate of the data stored in the buffer 39. For this reason, when predicting the release speed K of the buffer 39 on the host side, the compression speed of the notch 39 when the uncompressed data is stored is predicted by the model of the printer 3, etc. The rate (uncompressed data size NnZ compressed data size Nc) can also calculate the release speed K of the compressed data buffer 39. If the release speed of the notch 39 corresponding to the uncompressed data is Kn, the release speed バッファ of the buffer 39 can be calculated by the following equation (5).

K = Kn X Nn / Nc (5)

[0051] Further, the estimated remaining compression time Tcf used to obtain the first end time Tcp is This value varies depending on the host CPU capacity and task status. Since the printer driver 13 can acquire the conditions of the host 2 by itself, it can reflect the state of the host 2 in the prediction of the transfer end time of each data set.

FIG. 3 is a flowchart showing a process in which output data is divided into a plurality of sets and transferred to the printer 3 by the computer (host device) 2 in which the printer driver 13 is installed. In step 51, an event (print instruction) for printing the image data 81 in the host apparatus 2 occurs. In step 52, the determination function 25 determines that there is no compressed data set in the memory 14 for the first data set. In step 65, the second decision function 42 transfers the first data set as an uncompressed data set 82η.

[0053] Therefore, when the output job is started, time for compressing the first data set is saved. Data capacity of the first data set If the printer 3 contains enough information to start output, the time from the start of the job to the start of output of the printer 3 can be shortened.

Further, the transfer permission signal 85 of the first data set is a reception completion notification, and at the same time, the transfer rate R of the first data set is obtained. This transfer rate R can be used to predict the end time of the next data set. In addition, the free capacity Nb and release speed Κ of the noffer can be acquired as the actual values transferred from the first data set. These parameters can also be used to predict the end time of the next data set. Therefore, the test data is transferred to obtain the transfer rate R, and the time spent for that is also unnecessary. Also in these respects, the printer driver 13 can start data transfer immediately and can start printing in the printer 3. For this reason, it is possible to shorten the time for which the user waits for the start of printing.

[0055] When transfer of the first data set 82 is started in step 65, in step 58, the compression function 21 starts compression processing of the next data set 82. As a result, in the host device 2, the next data set 82 is compressed in parallel with the transfer of the first data set 82.

[0056] When the transfer of the previous data set is completed, a transfer permission is received from the printer 3 as a reception completion notification. A good signal 85 is transmitted. In step 53, when receiving the transfer permission signal 85, the printer driver 13 determines that the transfer of the current data set 82 can be started. At the timing of step 53 when the transfer of the current data set can be started, the transfer function 22 sets the transfer permission signal to the reception time Tt of the previous data set 82, the free space Nb of the buffer 39, and the release speed K of the buffer 39. Alternatively, it is obtained together with the reception completion notification 85.

[0057] In step 54, the determination function 25 determines whether the compressed current data 82c is stored in the memory 14. If it is stored, the first determination function 41 controls the selection means 24, and in step 55, the transfer of the compressed current data set 82c from the memory 14 is started. If there is no compressed current data set 82c in the memory 14, the second determination function 42 determines which of the cases A to C is present. In step 59, if the free space Nb of the nofer is smaller than the compressed data predicted value Nc; f, it corresponds to the case C. Therefore, in step 60, the process waits for the compression processing of the current data set 82 to be completed, and in step 55, transfer of the compressed current data set 82c is started.

In step 59, if the buffer free space Nb is larger than the compressed data predicted value Ncf, in step 61, the buffer free space Nb is compared with the data amount Nn of the uncompressed data set. Since the buffer free space Nb is smaller than the data amount Nn of the uncompressed data set, it corresponds to case B. Therefore, in step 62, for the second end time Tnp, an expression that takes into account the release speed Κ (3 ). If the free space Nb is larger than the data volume Nn of the uncompressed data set, it corresponds to case A. Therefore, in step 63, the formula (2) that does not consider the release speed K for the second end time Tnp. ) To predict. Note that the first end time Tcp is estimated using Equation (1) in all cases.

[0059] In step 64, the calculated first end time Tcp and second end time Tnp are compared. If the first end time Tcp ends first, in step 60, it waits until the compression processing of the current data set 82 is completed, and in step 55, transfer of the compressed current data set is started. If the second end time Tnp is expected to end earlier than the first end time Tcp, then in step 65 the compression is performed. Without waiting for the completion of processing, transfer of the current data set 82 is started without being compressed. By making such a determination, the total processing time of compression processing and transfer processing is optimized for each data set, and the processing time of the entire job can be shortened.

[0060] In step 56, it is determined whether all data sets have been transferred. If there is an untransferred data set, step 57 checks whether the next untransferred data set has been compressed. If compression has not started, the compression function 21 starts compression of the next data set in step 58. If the compression function 21 is compressing the current data set, it is interrupted and compression of the next data set is started. As a result, useless compression work can be minimized, and compression processing of the next data set can be started early. This increases the likelihood that the compressed data set can be transferred in step 54, further improving the overall job processing time.

The printer driver program 13 for performing the processing shown in FIG. 3 is a program or program product having instructions that can execute each step. The program product can be provided by being recorded on a suitable recording medium such as a CD-ROM or via a computer network.

FIG. 4 is a flowchart showing a process for receiving data in the printer 3. In Step 71, the printer 3 starts receiving the current data set 82 that has been compressed or not compressed. In step 72, when all of the current data set 82 is stored in the buffer 39, in step 73, the notification function 46 causes the time Tt required to receive the current data set 82, the free space Nb of the nofer 39, and Information including the release rate K of the buffer 39 is returned to the host 2 together with the transfer permission signal 85. In the printer 3, in parallel with the reception process, if there is a data set in the nota 39, the compressed data is decompressed by the decompression unit 34, and the uncompressed data is not decompressed and sent to the printing mechanism 37. Print.

[0063] The control program (firmware) 40 for performing the processing shown in FIG. 4 is a program or program product having instructions capable of executing each step. This program product can be provided on a suitable recording medium such as a CD-ROM or provided on a computer network. Can be provided via a network.

FIG. 5 is a timing chart showing an example of a print job executed in the system 1 including the host 2 and the printer 3. When a print event occurs at the time tO in the host 2, the first data set 82 is transferred to the printer 3 without being compressed according to the determination by the second determination function 42. When the transfer of the first data set 82 is started, the compression function 21 starts the next compression process of the data set 82.

[0065] When all the uncompressed head data set 82η is stored in the buffer 39 at time tl, the printer 3 starts printing the data set 82η. The printer control function 40 returns a transfer permission signal 85 to the host 2. At the same time, it sends to the host 2 the transfer rate R, the free space Nb of the buffer, and the buffer release rate K.

In the printer driver 13, when the transfer permission signal 85 is received from the printer 3, the time t2 is the time when the next data set 82 can start to be transferred. In this example, the compression processing of the next data set (current data set based on time t2) 82 is not completed at time t2 when transfer can be started. Therefore, the second determination function 42 determines the conditions of cases A to C. In case B, the first end time Tcp is calculated using equation (1), and the second end time Tnp is calculated using equation (3) with the buffer release speed K taken into account. The second end time Tnp may be shorter than the first end time Tcp even if it is expected that the transfer will occur at the release rate Κ after the nofler becomes full. Therefore, at time t2, transfer is performed using the uncompressed data set 82η without waiting for the completion of the compression process of the current data set 82. At the same time, the compression process for the next data set 82 is started. In this case, the timing when the transfer can be started and the timing when the transfer starts are substantially equal.

When all uncompressed current data set 82η is received by printer 3 at time t4, similarly to the above, transfer permission signal 85 and other parameters are transmitted from host 3 to host 2. When host 2 receives transfer permission signal 85 and other information at time t5, transfer of the next data set 82 can be started. The current data set 82 has already been compressed and stored in the memory 14 at a time t3 before the transfer start time t5, and the compression function 21 further compresses the next data set 82. Yes. For this reason, at time t5, the first determination function 41 determines the transfer of the compressed current data set 82c. Transmission starts. When all the compressed data sets 82c are received at time t6, the transfer start signal 85 is notified again from the printer 3 to the host side.

When the host 2 receives the transfer start signal 85 at time t7, the current data set 82 has not been compressed at time t7 at which transfer can be started. In addition, the buffer 39 of the printer 3 is almost full and the free space Nb is small. Therefore, the second determination function 42 determines that it is case C because the free space Nb is smaller than the compressed data predicted value Nc; f. Therefore, the second determination function 42 determines to start transfer of the compressed data set after waiting until time t8 when the compression of the current data set ends. Time t8 is when the transfer starts.

[0069] When all the compressed data sets 82c are received by the printer 3 at time t9, a transfer start signal 85 is returned to the host 2. When host 2 receives transfer start signal 85 at time tlO, transfer can be started. At time tlO, the current data set 82 has not been compressed. Therefore, the second determination function 42 predicts the first end time Tcp and the second end time Tnp. In this case, the second end time Τηρ is shorter than the first end time Tcp. Therefore, the current data set 82 is output as an uncompressed data set 82η without waiting for completion of the compression process.

[0070] The printer driver 13 predicts the transfer end time (end time) of each data set 82 by the transfer rate R, the notch capacity Nb, and the release rate K at that time when transfer can be started. Individual data sets are transferred in a timely manner. For this reason, each time the data set is transferred, the data set is selected so that the transfer time is shortened, so that the processing time of the entire output job can be shortened.

In the above example, the printer 3 is a peripheral device, the image data 81 is output data, the data is transferred to the printer 3, and the printed matter is printed by the printer 3. Peripheral devices may be other printing devices such as fax machines, but in some cases the peripheral device and the host are integrated. Furthermore, the output data is not limited to image data, and may be text data. In addition, peripheral devices include various devices that receive output data from a host device, such as a display device such as an LCD that generates (displays) image data as an image.

Claims

The scope of the claims

[1] A method including a step of dividing output data from a host device into a plurality of sets of transfer data and transferring the data to a peripheral device, wherein the transfer step compresses the plurality of sets of transfer data in order. Store in memory, select and transfer either compressed or uncompressed data sets.

If the current data set is not compressed when the transfer of the current data set can be started, the first time when the compressed current data set is transferred.

Predict the end time of 1 and the second end time when the uncompressed current data set is transferred, transfer the current data set with a short predicted end time,

A method including starting compression of the next data set if compression of the next data set is not started when the transfer of the current data set is started.

[2] The method of claim 1, wherein the transferring step includes predicting the first end time and the second end time based on a transfer rate of a previous data set.

[3] The transferring step includes the transfer rate or information for obtaining the transfer rate.

3. The method of claim 2, comprising obtaining along with a transfer permission signal from the peripheral device.

[4] The transferring step further includes the predicted data amount of the compressed current data set when the data size is larger than the free space of the buffer of the peripheral device allocated for data transfer. 2. The method of claim 1, comprising transferring the data set.

[5] In the transferring step, the predicted data amount of the compressed current data set is smaller than a free capacity of the buffer of the peripheral device, and the data amount of the uncompressed current data set is further reduced. 2. The method of claim 1, comprising: predicting the second end time based on a transfer rate of a previous data set and a release rate of the buffer when larger than a free capacity of the buffer.

[6] An apparatus having transfer means that divides output data into a plurality of sets of transfer data and transfers the data to a peripheral device, and enables the peripheral device to generate an output based on the output data, The transfer means compresses the plurality of sets of transfer data in order and stores them in a memory, selects and transfers either a compressed data set or an uncompressed data set, and the transfer means further includes:

If the current data set is already compressed when the transfer of the current data set can be started, the compressed current data set can be transferred,

Predicting the end time of 1 and the second end time when the uncompressed current data set is transferred, and transferring the current data set with a short predicted end time,

A device that makes a determination including starting compression of the next data set if compression of the next data set has not started when the transfer of the current data set is started.

7. The apparatus according to claim 6, wherein the transfer means predicts the first end time and the second end time based on a transfer rate of a previous data set.

8. The apparatus according to claim 7, wherein the transfer means acquires the transfer rate or information for obtaining the transfer rate together with a transfer permission signal from the peripheral device.

[9] The transfer means further includes:

The predicted data capacity of the compressed current data set is larger than the free space of the peripheral device's buffer allocated for data transfer, and when the compressed data set is transferred, 7. The apparatus of claim 6, wherein

[10] The transfer means may be configured such that the compressed current predicted data amount is smaller than the free space of the buffer of the peripheral device, and the data amount of the uncompressed current data set is stored in the buffer. 7. The apparatus according to claim 6, wherein when it is larger than the free capacity, the second end time is predicted based on a transfer rate of a previous data set and a release rate of the buffer.

[11] A system having a host device and a printer that prints based on output data divided and transferred from the host device into a plurality of sets of transfer data,

The host device compresses the plurality of sets of transfer data in order and stores them in a memory, and selects and transfers either a compressed data set or an uncompressed data set. The transfer means further comprising:

If the current data set has already been compressed when transfer of the current data set can be started, the compressed current data set is transferred.

Predict the end time of 1 and the second end time when the uncompressed current data set is transferred, and transfer the current data set with a short predicted end time,

When starting the transfer of the current data set, if the compression of the next data set has not started, the system performs a determination including starting the compression of the next data set.

[12] The transfer means predicts the first end time and the second end time based on the transfer rate of the previous data set,

12. The system according to claim 11, wherein the printer includes means for transmitting the transfer speed or information for determining the transfer speed together with a transfer permission signal.

[13] The transfer means further includes:

A predicted data capacity of the compressed current data set is determined to include a transfer of the compressed current data set when it is larger than a free space in the printer buffer allocated for data transfer; The system of claim 11.

[14] The transfer means may be configured such that the compressed predicted data amount is smaller than the free space of the printer buffer and the data amount of the uncompressed current data set is empty in the buffer. 12. The system of claim 11, wherein if greater than the capacity, the second end time is predicted based on a transfer rate of a previous data set and a release rate of the notifier.

[15] A device driver program for dividing output data from a computer into a plurality of sets of transfer data and transferring the data to a peripheral device, and generating an output based on the output data in the peripheral device,

The plurality of sets of transfer data are sequentially compressed and stored in the memory of the computer, and either the compressed data set or the uncompressed data set in the memory is selected. Transfer process, and this transfer process includes

If the current data set is not compressed, the first end time when the compressed current data set is transferred and the second end time when the uncompressed current data set is transferred And transfer this dataset with a short predicted end time,

The program includes starting compression of the next data set if compression of the next data set is not started when the transfer of the current data set is started.

16. The program according to claim 15, wherein the transferring process includes predicting the first end time and the second end time based on a transfer rate of a previous data set.

17. The program according to claim 16, wherein the process of transferring includes acquiring the transfer speed or information for obtaining the transfer speed and the peripheral device power together with a transfer permission signal.

[18] The process to be transferred is further performed when the compressed current data set has a predicted data capacity greater than the free space of the peripheral device allocated for data transfer. 16. The program of claim 15, comprising transferring a data set.

[19] In the transfer process, the predicted data amount of the compressed current data set is smaller than an available buffer capacity of the peripheral device and the data amount of the uncompressed current data set is further reduced. 16. The program according to claim 15, further comprising: predicting the second end time based on a transfer rate of a previous data set and a release rate of the buffer when the capacity is larger than an empty capacity of the buffer.