Abstract:
Disclosed is a method and apparatus for adjusting an optimum printing speed. The method includes the steps of converting a print data into a data having a predetermined size unit; calculating the time required for transmitting the converted data to a printer according to a predetermined rule; and performing a preprocessing print for printing the received data by doing the printing environment recognition operation earlier as much as a transmission time during the converted data is received, thereby enhancing the printing speed so that the printer engine can start the print environment recognition operation earlier as much as the time for transmitting the data from a host computer to the printer.

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for A Method For Adjusting an Optimum Printing Speed earlier filed in the Korean Industrial Property Office on Dec. 27, 1996 and there duly assigned Ser. No. 74197/1996. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method and apparatus for adjusting a printing speed, and particularly, to an improved method for achieving an optimum printing speed capable of realizing a quick printing by performing a print environment recognition operation in advance through driving a printer as fast as a data transmission time. 
     DESCRIPTION OF THE RELATED ART 
     Conventionally, the printing speed of a printer system is limited because of the time needed to perform a print environment recognition operation. 
     One type of print environment recognition operation is a printer warm-up occurring before the actual printing. A second type of a print environment recognition operation is a printer initialization occurring before the actual printing. For example, U.S. Pat. No. 5,216,754 for Determining the Complexity of a Page Prior to a Print Attempt to Sathi et al analyzes the quantity, size, geometry, and location of objects on a page prior to the printing of a page. U.S. Pat. No. 5,687,302 for a Method of Transferring Recording Data to Recording Device to Kawase determines beforehand the available memory capacity of an input device before printing. I have not seen a method or apparatus that performs a print environment recognition operation in an efficient manner so that the printing operation is not slowed down. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide an improved printing operation. 
     It is also an object to perform a printing operation enhancing the speed of a printer engine, by reducing a time required for recognizing a print environment of the printer engine. 
     It is yet another object to provide an improved method and apparatus for adjusting the printing speed. 
     It is also another object to provide a more efficient printing operation that efficiently determines the print environment recognition operation in printing a page of text. 
     To achieve these and other objects, a method for adjusting an optimum printing speed according to the present invention includes converting print data into data having a predetermined size unit; calculating the time required for transmitting the converted data to a printer according to a predetermined formula; and performing a preprocessing print for printing the received data by doing the printing environment recognition operation earlier by as much as a transmission time during the converted data is received. 
     Preferably, the step of performing the preprocessing print includes the steps of determining a printing amount of time; rendering the transmitted data continuously; and printing the rendered data by driving the printer engine after the printing amount of time elapses. Preferably, the predetermined formula is a time which is obtained by dividing the size value of the converted data by a transmission speed at between a host computer and the printer. Preferably, the printing amount of time is the transmission time. Preferably, the predetermined size unit is one page. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of this invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein: 
     FIG. 1 is a block diagram illustrating a print environment; 
     FIG. 2 is a block diagram illustrating a laser printer; 
     FIG. 3 is an instruction format illustrating an instruction informing a printer of a data size corresponding to one page; 
     FIG. 4 is a flowchart illustrating a method for processing the print data in a printer driver of a host computer according to the present invention; 
     FIG. 5 is a flowchart illustrating a method of performing a preprocessing print according to the present invention; and 
     FIG. 6 is a flowchart illustrating a process for controlling an engine signal transmittal according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First, a print environment shall be discussed. FIG. 1 is a block diagram illustrating a print environment. As shown in the drawing, the print environment includes an application program  11 ; a printer driver  12  for converting the image data generated by the application program  11  into print data which the printer can recognize; an input/data (I/O) device  13  for transmitting the print data; and a printer  14  which is connected to the I/O device and prints data corresponding to one (1) page by interpreting print data transmitted. The printer driver  12  can be a computer program residing in host computer  10 . 
     FIG. 2 is a block diagram illustrating a laser printer. As shown in the drawing, the laser printer includes a controller unit  20  for decoding the print data transmitted from a host computer  10  and for controlling the printing operation; and a printer engine  25  forming an image on a recordable medium according to the control of the controller unit  20 . The controller unit  20  is composed of a central processing unit (CPU)  21 ; a RAM  22 , a ROM  23 ; and an input/output (I/O) driving device  24 . 
     The printing operation of the laser printer of FIG. 2 having the above-described structure will be explained as follows. First, the document created by the application program  11  is converted from image data into the print data which the printer  14  can recognize. This conversion is performed by the printer  12  provided in the host computer  10 . After that, the print data is transmitted to a serial port or a parallel port of the printer  14  through the I/O device  13  of the host computer  10 . The printer  14  receives the transmitted instruction, i.e., print data, and converts the portion of the print data corresponding to one page into a bitmap format which the printer engine  25  can recognize. A print signal is then transmitted to the printer engine  25 . The printer engine  25  recognizes the present print environment for printing in an optimum condition and determines a fixing temperature of a developing machine according to the print environmental condition (such as a temperature, a humidity, etc.). After that, the printer engine  25  fixes a toner of the developing machine on a recordable medium by the electric pressure using a driving circuit. At this time, after the printer enables the printer engine  25  to recognize the print environment, the actual printing operation is commenced. In other words, it is necessary to warm up the printer engine  25 . The phrase “printing environment” is used interchangeably with the phrases “engine environment” and “print environment.” 
     Accordingly, because the printer needs to enable the printer engine  25  to recognize the print environment before starting the printing operation, the actual time for printing becomes delayed depending upon the time for performing the print environment recognition operation by the printer engine  25 , thereby decreasing the printing speed. Moreover, in the case where multiple pages need to be printed one at a time, because the print environment needs to be recognized whenever printing is performed, the print speed appears to be very slow to users. 
     In the case of continuous printing of the multiple pages, as the print environment which has previously been recognized is continuously used, the decrease of the printing speed is less pronounced. However, when the documents to be printed become more complicated then the amount of the data to be transmitted for each page becomes large. Accordingly, the printer engine  25  can be suspended for each page to be printed. Or, it can be suspended due to the amount of the data for each page, if the input buffer of the printer is small. As it is necessary to have time for performing the print environment recognition operation, the printing speed can decrease. 
     The time for transmitting data can be calculated using a characteristic of the printing operation as follows. In the case that a user wants to print the image data in an application program  11 , a printer driver  12  of a host computer  10  converts the image data to be printed into print data which a printer  14  can recognize and transmits the print data to the printer  14 . At this time, the printer driver  12  can recognize an overall size of the instruction of a page which is to be printed. Moreover, by selecting an input/output (I/O) device  13  of the host computer  10 , the print data is transmitted to the printer  14 . In this case, as the transmission speed is already known, it is possible for the printer driver  12  or the printer  14  to look for the amount of print data corresponding to one page. In other words, it is possible to know the time required for transmitting the print data corresponding to one page from the host computer  10  to the printer  14 , when the amount of print data corresponding to one page is divided by the transmission speed. The transmission time can be calculated using the following equation: 
     amount of print data corresponding to one page 
     
       
         Transmission time=. . .  
       
     
     transmission speed 
     A simple example of the use of the above equation can be shown. If the “amount of print data corresponding to one page” equals 100,000 bytes, and the “transmission speed” equals 28,000 bytes per second, then the “transmission time” shall equal 3.47 seconds. 
     In the present invention adopting the above-identified equation, in the case that the printing operation is performed starting from the host computer  10 , the printer driver  12  calculates the amount of print data corresponding to one page and informs the printer  14  of the calculated amount. The conventional technologies use a printer that performs the print environment recognition operation of the printer engine  25  upon receiving actual print data. However, the printer  14  of the present invention calculates the transmission time using the above-identified equation after receiving from the printer driver  12  the calculated amount of print data corresponding to one page. The printer  14  uses the amount of print data corresponding to one page along with the established value of the transmission speed, thereby performing the print recognition operation earlier by as much as the calculated transmission time. For this purpose, a new instruction  32  for informing the printer  14  of the amount of print data corresponding to one page shown in FIG. 3 is added to the printing instruction  30  used in the conventional technologies. 
     In other words, in the conventional technologies the instruction  32  was not used. The conventional technologies only used instruction  30 . 
     FIG. 4 is a flowchart illustrating a method for processing the print data in the printer driver  12  of the host computer  10  according to the present invention, and FIG. 5 is a flowchart illustrating a method of performing a preprocessing print according to the present invention. In addition, FIG. 6 is a flowchart illustrating a process for controlling an engine signal transmittal according to the present invention. 
     The printing order will be explained, with reference to the drawings. First, a document is created by an operator using application program  11  in host computer  10 . When the document is to be transmitted to the printer  14  attached to the host computer  10 , the printer driver  12  receives the image data to be printed from the application program  11  and processes the image data, as shown in the flowchart of FIG.  4 . In other words, at step  41  the printer driver  12  designates a format of the data to be printed. Then a step  42 , the printer driver  12  converts the image data into print data. The printer  14  can recognize and print the print data. The conversion of the image data into the print data is repeatedly performed until there is one page of print data. At step  43 , the data corresponding to one page are all converted. Then at step  44 , amount of print data corresponding to one page is determined. Then at step  45 , the printer driver  12  processes the print data corresponding to one page to form the instructions  30  and  32  shown in FIG. 3, and transmits instructions  30  and  32  to the printer  14  through the I/O device  13 . At step  46 , the printer  12  transmits the print data to be printed to the printer  14  through the I/O device  13 . 
     Refer now to FIG. 5, which illustrates a method of performing a preprocessing print according to the present invention. As shown in FIG. 5, the printer  14  performs the preprocessing printing. At step  51 , the printer  14  determines whether it has received data from the host computer  10 . If printer  14  has received data, then step  52  is performed. At step  52 , the printer  14  determines whether the data received is the instruction  32  or is the print data. If printer  14  receives instruction  32  then step  53  is performed at step  53 , the data transmission time is calculated by the printer driver  12  using the above-identified equation with the value of the amount of print data corresponding to one page included in the page size instruction  32  and the established transmission speed of signals converted between the host computer  10  and the printer  14 . Also at step  53 , the calculated transmission time is stored in a timer (not illustrated in the drawing) provided in the printer  14 . The calculated transmission time is used in conjunction with an engine signal transmittal routine shown in FIG.  6 . At this time, the transmission time is calculated by the printer driver  12  of the host computer  10  and then the transmission time is conveyed to the printer  14 . 
     Before the transmission time elapses, the step  54  is performed. At step  54 , the engine signal transmittal routine of FIG. 6 is called so that the printer engine  25  can perform the print environment recognition operation before the transmission time elapses. In other words, the printer engine  25  is instructed, that the print environment recognition operation should be performed earlier by as much as the transmission time. Thus, the print environment recognition operation (which can include a printer warm-up, a printer initialization, a sensing of temperature, a sensing of humidity, etc.) is performed before the transmission time elapses. Suppose the transmission time is 3.47 seconds and a printer warm-up time is 5.0 seconds. Then, using conventional technology, the print data would begin to be recorded onto a recordable medium after 8.47 seconds elapse. Thus, a printer preparation time using conventional technology can be said to be 8.47 seconds. However, using the present invention, the print data would begin to be recorded onto the recordable medium after 5.0 seconds. Thus the printer preparation time for the present invention can be said to be 5.0 seconds. One way in which the present invention accomplishes the savings in time is by simultaneously performing the printer warm-up and performing the transmission of print data to the printer. Conversely, the conventional technologies do not simultaneously perform the printer warm-up and the transmission of print data to the printer. 
     Referring to FIG. 6, the operation of the engine signal transmittal routine is explained. A counting operation is performed during the time corresponding to the transmission time stored in the timer. When the value of the counter corresponds to the transmission time, the printing signal is transmitted to the printer engine  25 . At step  60 , the counter value is determined. Next, at step  62 , the counter value is compared to the value zero. If the counter value at step  62  does not equal zero, the step  64  is performed. At step  64 , the value of the counter is decreased by one. Then step  60  is performed again, to determined the current value of the counter. If the counter value at step  62  does equal zero, then this means that the value of the counter corresponds to the transmission time. Thus, step  66  is performed. At step  66 , the printing signal is transmitted to the printer engine  25 , after which the printer engine  25  can print the print data on a recordable medium. If the result of the determination, of step  52  is that the instruction  32  is not received, then step  55  is performed. At step  55 , print data which is transmitted is continuously received until the transmitted print data correspond to one page. 
     At step  56 , an amount of print data has been received which correspond to one page. At this time, as shown in FIG. 6, at step  66  when the value of the counter corresponds to the transmission time (that is, when the value of the counter becomes zero), the printing signal is transmitted to the printer engine  25  and the print data which has received and rendered until then is printed. In other words, while the timer performs the counting operation to instruct the warming up of the printer engine  25 , the printer  14  receives the print data to be printed and performs rendering. The printer  14  warms up the printer engine  25 , and the print data is transmitted to the printer engine  25  to perform the printing operation. 
     A method is described above to overcome the problem of a printing time being delayed due to the time required to perform the environment recognition operation of the printer engine  25 . When the printing signal is received to the printer engine  25  when performing the printing operation, the host computer  10  transmits the data transmission time and enables the printer engine  25  to perform the print environment recognition operation. Thus, the print environment recognition operation is performed before all print data is transmitted from host computer  10 , thereby saving time. As the delayed time is removed, users can perform the printing operation more quickly. 
     While there have been illustrated and described what are considered to be preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the present invention. In addition, many modifications may be made to adapt a particular situation to the teaching of the present invention without departing from the central scope thereof. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the present invention, but that the present invention includes all embodiments falling within the scope of the appended claims.