JP2617909B2 - Laser printer device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser printer, which is one of output devices and prints on paper based on image data in a semiconductor memory using a laser beam. .

2. Description of the Related Art In recent years, laser printers, which are one type of output devices, have been improved in speed and resolution, and data to be output is stored in a semiconductor memory or the like as image data including an upper margin and the like. There is a method to output,
Due to the high resolution, the capacity is large and the cost is high.

Hereinafter, a conventional laser printer will be described focusing on a margin setting circuit. FIG. 5 is a block diagram of an upper margin setting circuit in a conventional laser printer. Here, (11) is a latch for holding the state of the signal at the fall of the TOP / signal.
The print start signal generation circuit (12) is operated only at the time of, and is reset at the time of LOW. The print start signal generating circuit (12) generates a PRST / signal for giving a timing of starting a printing operation during the above operation. The TOP / signal is a signal that indicates that the head of the paper to be printed is at the output position, the PEND / signal is a signal that indicates the end of the current printing operation, and the LSYN / signal is a horizontal synchronization that indicates the start of each line. The signal and PRST / signal are signals for notifying the start of printing, and in synchronization with this, serial data to be printed out starts to be output. Here, "/" at the end of the signal name is a sign indicating that it is negative logic.

FIG. 6 shows an example of a timing chart of each signal in FIG. FIG. 7 shows the relationship between the entire image data area to be printed out, each margin area, and the area printed out as image data actually output.

The conventional upper margin setting circuit thus configured will be described below. In a certain printout operation,
At the end of the print operation immediately before the start of the
The PEND / signal becomes active as shown at point A1 in the figure,
In synchronization with this, the latch (11) in FIG. 5 is reset,
Also, the PRST / signal becomes non-active. Thereafter, the current printing operation starts. First, when the TOP / signal indicating the head of the paper to be printed becomes active as shown at point B1 in FIG. 6, the latch (11) is activated in synchronization with the falling edge thereof. (HIGH), the print start signal generation circuit (12) in FIG. 5 is set in an operable state (enable state), and immediately thereafter, as shown at point C1 in FIG.
The PRST / signal becomes active in synchronization with the falling edge of the LSYN / signal, output as serial data from the beginning of the image data area, starts printing, and is output until the PRST / signal is deactivated by the PEND / signal. Perform the operation.

Here, the relationship between the area that can be used as the image data to be actually output in the entire area of the image data and the area that is set as each margin, the output data is blank as the output state, and cannot be used as the data area to be printed out. This will be described with reference to FIG.

In FIG. 7, the D × E A area is the entire area of the image data. Here, as described above, since the image data is printed out from the beginning, the portion surrounded by D × C must be left blank, which is wasteful. When the left margin is set as shown in FIG. 7, the area to be printed out is a portion B surrounded by oblique lines.

Problems to be Solved by the Invention As described above, the conventional configuration has a disadvantage that an unusable area is formed in the entire area of the image data, and the use efficiency is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser printer capable of eliminating the above-mentioned conventional drawbacks and removing a blank portion as an upper margin setting area to reduce an image data area. .

Means for Solving the Problems The present invention, in order to solve the above problems, to output image data as storage data from the semiconductor memory,
In a laser printer device that prints on printing paper by the laser printer body based on the image data, a top signal detection circuit that detects the arrival of the upper end of the printing paper and outputs a signal, and a signal obtained from the laser printer body. An upper margin counter that counts a horizontal synchronization signal indicating the start of scanning of each line, and an upper margin setting register that stores the number of horizontal synchronization signals to be counted by the upper margin counter. The counter starts counting when receiving a signal from the top signal detection circuit, and starts outputting image data when the counted value matches the value stored in the upper margin setting register. Is output to the semiconductor memory to notify the start of printing.
The serial data to be printed out starts to be output by the PRST / signal, and the printing operation is performed.

Operation With this configuration, instead of having the conventional upper margin setting area, the top signal detection circuit starts printing by the set value of the upper margin counter from the time when the top signal detection circuit detects the arrival of the upper end of the printing paper and outputs a signal. The output of serial data is stopped by delaying the output of the
During this time, only the paper is sent and becomes blank, so that the upper margin can be set and the image data area can be reduced.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of an upper margin setting circuit in a laser printer according to an embodiment of the present invention. (21) TOP / informs you that the top of the paper to be printed has come
This is a top signal detection circuit that outputs a PRESET / signal in synchronization with the falling edge of the signal. (22) is reset by the PEND / signal which is a print operation end signal immediately before the PEND / signal notifying that the current print operation has been completed, and the top signal detection circuit (21) performs the next print operation. The upper margin counter is loaded with the upper margin value set in the upper margin setting register (23) in synchronization with the output PRESET / signal. After the upper margin value is loaded, start each line. LSYN of horizontal synchronizing signal to inform
Counts down at the falling edge of the / signal, and when the count reaches 0, outputs the PRST / signal, which is the print operation enable signal, and starts outputting the serial data to be printed out.
A printing operation is performed. The upper margin setting register (23) sets the upper margin value set in the upper margin counter (22) by a WT / (write) signal.

FIG. 2 shows an example of a timing chart for explaining the operation of the circuit shown in FIG. Here, all signals are of negative logic. FIG. 3 shows the relationship between the entire image data area to be printed out, each margin area, and the area to be printed out as actually output image data.

The operation of the upper margin setting circuit in the laser printer according to the present embodiment thus configured will be described below.

In Fig. 2, when the print operation immediately before the printer is completed at point A3 and the PEND / signal becomes active, the PRST / signal becomes inactive in synchronization with it and the transmission of serial data to be printed out ends. I do. Then, the operation proceeds to the next printing operation. When the TOP / signal becomes active at the point B3, the PRESET / signal becomes active in synchronization with it, and the upper margin counter (22) in FIG. Is loaded, and the upper margin counter (22) starts subtracting from the LSYN / signal at the point C3 immediately after that, and the LSYN / signal at the point D3 becomes 0.
When the count is completed, the PRST / signal becomes active in synchronization with the count, starts the print operation, and prints out the output image data as serial data. In this way, at the beginning of the print paper during the current print operation, the LSYN / signal at point D3 becomes active and the PRST / signal becomes active immediately after the TOP / signal becomes active at point B3 of the position detection point. Until a certain point, only the paper is sent and no image data is output, so that the upper margin is between them. Also, the range can be arbitrarily set with the accuracy of the highest resolution in the vertical direction (upper and lower dot intervals) by changing the contents of the upper margin setting register (23), and the upper margin area is used as a memory as in the conventional example. There is no need to reduce the image data area.

FIG. 3 illustrates this situation. In FIG. 3 to which the explanation is added, the area A of D × C is the entire image data area, and the area D × C of FIG. The area B in the shaded area of E × D excluding the area becomes the effective use area of the output image data.

FIG. 4 shows the position of the upper margin setting circuit in the laser printer apparatus in the laser printer controller. Here, (1) is a laser printer main body that prints based on image data output from a semiconductor memory (not shown in FIG. 4);
(2) a laser printer interface section (3), an upper margin setting circuit (4), a single board computer section (abbreviated as SBC section in FIG. 4, hereinafter abbreviated as SBC section) (5), A laser printer controller comprising a bus arbitration circuit (6) and controlling printing by the laser printer body (1) through an interface line.

Then, the laser printer interface section (3) connects the internal bus from the SBC section (5) to the laser printer main body (1) through an interface line. The upper margin setting circuit (4) is the first
It operates as described with reference to FIG. 2 and FIG. SBC
The section (5) is connected to the laser printer interface section (3) through an internal bus, and transfers the WT / signal and setting data shown in FIG. 1 to the upper margin setting circuit (4). Send out through the bus. The bus adjustment circuit (6) adjusts the connection timing of the internal bus between the laser printer interface (3) and the SBC (5).

As described above, according to the present invention, instead of having the upper margin area as a blank in the image data area, the top signal detection circuit detects the arrival of the upper end of the printing paper and outputs the signal to set the upper margin. The output of the PRST / signal is delayed by the number of LSYN / signals of the set value loaded from the register for the upper margin counter into the upper margin counter. It is possible to realize an excellent upper margin setting circuit which can reduce the number of the upper margins.

[Brief description of the drawings]

FIG. 1 is a block diagram of an upper margin setting circuit in a laser printer device showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of a timing chart at the time of operation of the upper margin setting circuit of FIG. FIG. 3 is a diagram showing the relationship between the entire area of the image data when the circuit of FIG. 1 is used, the upper margin, the left margin, and the image data area to be actually output, and FIG. FIG. 5 is a diagram showing the positioning of a margin setting circuit in a laser printer controller, FIG. 5 is a block diagram of an upper margin setting circuit in a conventional laser printer device, and FIG.
FIG. 7 is a diagram showing an example of a timing chart at the time of operation in the circuit of FIG. 5, and FIG. 7 is a diagram showing the entire image data area, the upper margin, the left margin, and the image actually output when the circuit of FIG. FIG. 4 is a diagram illustrating a relationship with a data area. (21) Top signal detection circuit, (22) Top margin counter, (23) Top margin setting register, (TO
P /): A signal that indicates that the beginning of the paper to be printed has reached the print start position, (PEND /): A signal that indicates the end of the printing operation, (LSYN /): Horizontal synchronization that indicates the beginning of each line Signal, (PRST /) ... Signal to notify start of print operation, (PRESET /) ... Load pulse to upper margin counter

Claims (1)

(57) [Claims] 1. A laser printer which outputs image data as storage data from a semiconductor memory and prints on printing paper by a laser printer main body based on the image data detects the arrival of the upper end of the printing paper. A top signal detection circuit for outputting a signal, an upper margin counter for counting a horizontal synchronization signal indicating the start of scanning of each line obtained from the laser printer main body, and a horizontal synchronization to be counted by the upper margin counter. An upper margin setting register for storing the number of signals, wherein the upper margin counter starts the counting when receiving a signal from the top signal detection circuit, and the counted value is used for the upper margin setting. A signal for starting output of image data when the value matches the value stored in the register; Laser printer apparatus and outputs for.