JPH0281658A - printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to printing devices such as liquid crystal printers, LED printers, and laser beam printers.

[Conventional technology]

In a printing device that prints on paper according to print data output from an external device such as a liquid crystal printer or an LED printer, an image is created on the paper in the following manner.

b) First, when print data is output from an external device such as a host computer, the printing device outputs this print data to -H
The print data is written into the receive buffer, and then the print data in the receive buffer is sequentially read out, converted into pattern data corresponding to the print data, and stored in the image memory.

(Example) When pattern data for 11 sheets of paper is stored in the image memory, an instruction is given to carry out the paper stored in the paper container, and the paper is carried into the printing device.

c) Thereafter, the paper carried into the printing device is temporarily stopped by a standby roll, and at the same time, pattern data is sent from the image memory to the print head and image formation on the photoreceptor drum is started.

2) The paper once stopped by the standby roll is fed again at the timing when the image (electrostatic latent image) on the photoreceptor drum is printed at a predetermined position on the paper, and an image is formed on the paper.

b) Furthermore, when printing the same image on multiple sheets of paper (hereinafter referred to as copy printing process), the next sheet is carried out from the paper center, and the pattern data stored in the image memory is stored in the same manner as above. Performs processing to print on the next paper.

[Problems with the prior art] However, in the above-mentioned printing device, the process shown in (a) is performed, that is, the print data is temporarily stored in the reception buffer, and then converted into pattern data and stored in the image memory.
After the process of writing pattern data for a page is completed, the process (b), that is, the process of instructing the paper cassette to output the paper once and carrying the paper into the printing device, is executed for the first time. Therefore, it takes time to insert the paper into the printing device, and printing processing on the first paper cannot be performed at high speed.

In addition, when performing copy printing processing, as explained in the process (e) above, after the printing process on the previous paper (preceding paper) is completed, the next paper (subsequent paper) is loaded into the printing device. Transport to. Therefore, the start of printing on the next paper is delayed,
As mentioned above, it takes a long time to print on subsequent sheets of paper.
Print processing cannot be performed at high speed.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide a printing device that can perform printing processing at high speed.

[Key points of the invention]

In order to achieve the above object, the present invention includes a storage means for storing print data input from an external device, and a printing device for printing on a sheet of paper carried out from a paper feed means based on the data stored in the storage means. wherein the determining means determines that the print data is input to the storing means; a detecting means detects the conveyance state of the preceding sheet discharged from the paper feeding means; and the determining means comprises the storing means. The paper feed control means causes the paper feed means to start a paper feed operation in response to the output of the detection means when it is determined that print data is present in the print data.

〔Example〕

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

FIG. 2 is a block diagram of a printing device according to an embodiment.

In the figure, the printing device is composed of an image forming section 1 that forms a toner image on a sheet of paper, and an F feeding mechanism 3 that carries out the sheet P from a paper cassette 2 and transports the sheet P through the printing device.

The image forming section 1 includes a photoreceptor drum 4, a charger 5, a printing gutter 6, a developer 7, and a transfer device 8, which are sequentially arranged near the circumferential surface of the photoreceptor drum 4.

The charger 5 applies an initial uJ]4iF electric voltage to the photosensitive surface of the photosensitive drum 4 rotating in the direction of the arrow, and the print head 6 is a device that exposes the photosensitive surface based on print data. The developing device 7 is a device that converts the electrostatic latent image formed on the photosensitive surface by the above-mentioned exposure into a toner image, and transfers the toner image from the transfer device 8 onto the paper P that is conveyed in the direction of arrow B.

The transport mechanism 3 includes a standby roll 10, a fixing roll 11, a transport roll (not shown), and a paper transport path 1 for transporting the paper carried out from the paper force center 2 by the rotation of the paper feed roller 9.
It is composed of a conveyance guide plate (not shown), etc., for forming the conveyance guide plate 2.

The standby roll 10 temporarily stops transporting the paper by bringing the leading edge of the paper into contact with it, rotates at a predetermined timing described later, and transfers the paper P between the photosensitive drum 4 and the transfer device 8.
This is a roll for general shipping. The fixing roll 11 is a roll that fixes the unfixed toner transferred onto the paper P by the transfer device 8 onto the paper P, and also conveys the paper P to the paper discharge section 13.

Further, a paper trailing edge detection sensor 14 is provided in the paper transport path 12 between the paper cassette 2 and the standby roll 10 to detect when the trailing edge of the paper passes. A standby switch 15 for detecting this is provided below the standby roll 10.

In the printing apparatus having the above mechanical structure, a control circuit having the block structure shown in FIG. 1 is provided on a substrate (not shown).

However, the host computer 17 shown in the figure is an external device that outputs print data to the printing device. The circuit within the printing device is composed of an interface control section 18 and a print section 19.

The interface control unit 18 converts the character code output from the host computer 17 into pattern data (
This is a circuit that performs conversion control to image data), and is controlled by the CPU (
The host interface (hereinafter referred to as host I/F) 21, ROM 22, RAM 23, reception buffer 24, image data generation section 25, and image memory 26 are configured.

In addition, the print unit 1-9 is a circuit that controls the output of pattern data when actually printing on paper, transports the paper P, and controls the operation of each part constituting the above-mentioned image forming unit 1.
It is composed of the above-described print head 6 and printer controller 27. Further, this print section 19 and the above-mentioned interface control section 18 are connected through a PR interface 28. The host computer 17 is a circuit that outputs character codes and print control data to the host I/F 21.

The CPU 20 controls each part according to a program stored in the ROM 22.

The image data generation unit 25 records character pattern data corresponding to the character code.1. α, and receive buffer 2
This circuit outputs the pattern data of the corresponding character to the image memory 26 when the character code once stored in the memory 4 is read out to the image data generating section 25 under the control of the CPU 20. The image memory 26 is a memory that stores bone pattern data for one page or multiple pages of paper. The printing driver drives a printing element such as a liquid crystal shutter (not shown) or an LED according to pattern data to expose the bright light surface as described above.

Further, the printer controller 27 exchanges control data with the CPU 20 described above, and controls the rotation of the paper feed roller 9 and the standby roll 10, and the drive control of the charger 5, the developer 7, the transfer device 8, the fixing roll 11, etc. This is the circuit that does this.

In the printing apparatus having the above configuration, the printing processing operation on paper will be explained according to the flowcharts shown in FIGS. 3(a) and 3(b).

The flowchart in FIG. 3(a) shows the processing on the interface control section 18 side, and the flowchart in FIG. 3(9) shows the processing on the printing section 19 side.

First, the CPU in the interface control section 18
20 monitors whether data such as character codes have been manually entered into the reception buffer 24, and when no data has been input into the reception buffer 24, a paper feed start (PFS) is performed.
) The output is set to a reset state (step (hereinafter referred to as S) l is N152). In this state, wait for data such as character codes to be output from the host computer 17,
When data such as character codes are output from the host computer 17, this data is input to the reception buffer 24 via the host I/F 21.

The CPU 20 immediately creates the above-mentioned PFS signal as soon as data such as character codes begins to be input into the reception buffer 24, and sends the R
This PFS signal is sent to the printer controller 27 of the printer unit 19 via the R interface 28 (
31 is Y, 53).

Thereafter, the CPU 20 determines whether there is an empty area in the image memory 26 for filling in the pattern data (S4).
'), if there is a write area, sequentially outputs the character codes in the reception buffer 24 to the image data generation section 27,
Image memory 2 after conversion to corresponding pattern data
6 <(S4 is Y, S5).

On the other hand, the printer controller 27 executes the paper feeding operation based on the above-mentioned PFS signal output from the CPtJ20 while the above-mentioned pattern data creation work is being performed on the interface control section 1st side (STI is Y, ST
2 (here, ST means step, and the letters ST are used to distinguish it from the above-mentioned process 5s on the interface control section 18 side)). printer controller 2
7 sends a rotation instruction signal to the paper feed roller 9 when the PFS signal is input, rotates the paper feed roller 9, and carries out the paper P from the paper cassette 2. When the paper l) carried into the printing device passes through the paper transport path 12 and reaches the standby roll 10, the standby sensor 15 is turned on. After determining that the paper refeed flag (to be described later) is not "P1", the printer controller 27 confirms that the standby sensor 15 is turned on, and then the paper feed roll 9 is turned on.
The rotation of is stopped (ST3 to 5T5). In this way, on the print section 19 side, the interface control section 1
While the pattern data is being written in the image memory 26 on the 8 side as described above, the paper P is carried out from the paper cassette 2, fed to the position of the standby roll 10, and temporarily stopped. The first half of FIGS. 4(a) to 4(C) are time charts showing the feeding timing of the paper P described above.

Thereafter, when the writing of the above-described pattern data into the image memory 26 is completed on the interface control unit 1st side (S6 is Y), the CPU 20 transmits a writing completion signal (IDR signal) to the printer controller 27 (S7). When the printer controller 27 receives the IDR signal (rise), if the paper feeding process for the paper P described above has been completed, the printer controller 27 sends a data sending permission signal (■5) as confirmation.
YN) to CPU 2' O (Sr6 is Y,
5T7). When the CPU 20 receives the VSYN signal, it transmits the pattern data written in the image memory 26 together with a valid signal (VAL) to the print section 19 (38 to 510), and the print head 6 performs exposure according to the pattern data. (Sr8 is Y, 5T9). The time chart showing the output timing of each of the above signals is shown in the fourth section.
Figures (d) to (first half of □□□).

Thereafter, when the transmission of the pattern data is completed on the interface control unit 18 side, the CPU 20 stops outputting the valid signal and transmitting the pattern data, and decrement the sheet number counter by 1. 0” (311
~514).

This judgment of the count value of the sheet number counter is performed during the copy printing process for two or more sheets, and as mentioned above (even if the printing process on the first sheet is completed, it does not become "°0" ( "1" or more, (k) in Figure 4, CPU20
returns to the above-mentioned process (S7).

On the other hand, on the printing section 19 side, after the printing section 6 starts the exposure operation as described above, a timer provided in, for example, the printer controller 27 is started (ST10). This timer is used to align the image formed on the photosensitive surface with the leading edge of the paper P, and while the timer times up (ST
11 is N), the image forming process of the print head 6, developer 7, etc. described above is executed, and image formation on the photosensitive surface, image development processing, etc. are performed (ST12). After that, when the timer times out, reset the timer and wait roll 1.
0 and sets the paper refeed flag (STII is Y, 5T13, 5T14, 5T15). Through this process, the paper P is conveyed to the transfer device 8 side, the toner image is transferred onto the paper P, and the toner image is further fixed on the paper P by the fixing device 11. After that, printer controller 2
7 continues conveying the paper and continues executing the above-described image forming process (ST12). During that time, it is determined whether the trailing edge of the paper P is detected by the trailing edge detection sensor 14 (ST16). Before the trailing edge of the paper P is detected by the trailing edge detection sensor 14 (ST16 is N), the process (Sr1) is executed to determine whether the paper refeed flag is set to 1° and the standby switch is turned off. Y, 5T17 is N)
, the above-mentioned process (Sr6→ST7→...) is repeated.

After that, when the trailing edge of the paper P is detected by the trailing edge detection sensor 14 (ST16 is Y), the process returns to the process (STI), and if the input of the PFS signal is determined and input (STI is Y), The paper feed roller 9 is driven to rotate and the next paper P' is carried out (Sr2). That is, while the preceding paper P is still being transported to the transfer device 8 side by the standby roll 10 and image formation processing is being performed on the paper P (ST3→5T17→
At ST6→ST7→・r・), the next paper P' is carried into the printing device. A diagram showing the above processing timing is shown in Figure 4 (
a), the latter half of (b), and (h) to (j).

After that, when all the paper P is sent from the standby roll 10 to the transfer device 8 side, the standby switch 15 is turned off (ST17 is Y), the printer controller 27 stops the rotation of the standby roll 10, and sets the paper refeed flag. II Set OII (ST18, 5T19).

During this time, the next sheet P' is being conveyed on the sheet conveyance path 12, and immediately after the standby roll 10 stops rotating, the next sheet P' comes into contact with the standby roll lO, turning on the standby switch 15. That is, when the paper refeed flag is set to "0", the judgment (ST3) becomes N, and the standby switch 15 is set to ON again by the paper P' being conveyed with an interval of, for example, about 10 mm from the paper P. Therefore, the feeding of paper P' is temporarily stopped by this process (ST3→5T5).

At this time, as described above, the IDR signal is sent from the CPU 20 to the printer controller 27, and the image memory 26
Printing is performed in the same manner as described above according to the pattern data written therein (ST6→ST7→...). That is,
When the printing process on the previous paper P is completed, the next paper P' has already been sent to the standby roll 10, and the printing process on the next paper P' can be executed immediately. When printing on the last sheet is completed, the sheet number counter becomes "0", so the CPU 20 stops outputting the TDR signal and ends the printing process (315).

In this embodiment, the timing for feeding the next paper P' is determined by the paper trailing edge detection sensor 14, but the timing for feeding the next paper P' is not limited to a configuration that detects the trailing edge of the paper. It may also be controlled by a timer that measures the conveyance time depending on the paper.

〔Effect of the invention〕

As explained in detail above, according to the present invention, while image data is being created, the first sheet of paper is carried to a predetermined position in the printing device, and the printing process can be performed at the same time as the image data creation is completed. During the printing process of the previous paper, the paper can be carried into a predetermined position in the printing device and processed immediately, so that printing can be performed at high speed.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of a printing device according to one embodiment, FIG. 2 is a configuration diagram of a printing device according to one embodiment, FIG. 3 is a flowchart explaining the operation of the printing device according to one embodiment, and FIG. 3 is a time chart illustrating the operation of a printing device according to an embodiment. 9... Paper feed roller, 10... Standby roll, 14... Paper trailing edge detection sensor, 15... Standby switch, 20... CPU. 27...Printer controller. Patent applicant Casio Electronics Industries Co., Ltd. Same as above
Casio Computer Co., Ltd. Figure 1

Claims (1)

[Scope of Claims] A storage means for storing print data input from an external device, and a printing device for outputting a print on a sheet of paper carried out from a paper feed means based on the data stored in the storage means, the storage means a determining means for determining whether the print data has been input into the means; a detecting means for detecting the conveyance state of the preceding paper carried out from the paper feeding means; A printing apparatus comprising: a paper feed control means for causing the paper feed means to start a paper feeding operation according to the output of the detection means when it is determined that the paper exists.