JPS6249779A - Printer controller - Google Patents

Abstract

PURPOSE:To record a picture with optional density from a high density to a low one using one printer by so constituting the titled controller that a control code inputted from an external equipment is decoded, the scan speed of a scanning means and the carrier frequency of a picture information are varied, and the recording density is varied. CONSTITUTION:At the head of sentence information A consisting of character codes transmitted from the external equipment, a control code to designate the recording density of the printer is included as a control code from the host computer. Receiving the said code, a main control part 3 decodes the contents, and outputs a variation signal L to a register 12 to vary the main scanning speed. The said signal L is converted to an analog information by a D/A converter 13, and transmitted as a motor-speed signal M to the driver of a motor. Also, the part 3 sets a selection signal J in a selector 10 to select the carrier frequency of a dot pattern data D in response to the recording speed designation. Accordingly an appropriate clock from one of the clock generators 11a-11d is selected, and the clock signal K to carry the dot pattern data D is read out and transmitted to a control part 6 and a parallel-to-series converter 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer control device for an image recording device such as a laser beam printer that records or outputs image information.

[Conventional technology]

FIG. 3 is a perspective view of a laser beam printer showing an example of this type of device, in which 21 is a laser oscillator, 22 is a reflecting mirror, and guides the laser beam emitted from the laser oscillator 21 to a modulator 23.

A beam expander 24 expands the beam diameter of parallel light. 25 is a motor such as a synchronous motor,
The polyhedral rotating mirror 26 is rotated at a constant speed. Reference numeral 27 denotes an imaging lens having f/θ characteristics, which sweeps the laser beam LB scanned by the polyhedral rotating mirror 26 in parallel to uniformly form an image on the photosensitive drum 28 . 29 is a charger, and a photosensitive drum 28
is uniformly charged. A developing device 30 visualizes the latent image formed on the photosensitive drum 28 using a developing material such as toner. A transfer charger 31 transfers the visualized toner image onto the recording paper 32. 33 is a cleaner section that collects the remaining developer material. 34 is a beam detector, for example, a PIN
Consists of photoelectric conversion elements such as diodes with fast response times,
The position of the swept laser beam LB is detected and a detection signal E2 (described later) is output. Reference numeral 35 denotes a drum rotation position detector, which is composed of, for example, a Hall element that utilizes the known Hall effect. Accordingly, when passing through the drum rotational position detector 35, the rotational position of the photosensitive drum 28 is detected by the Hall effect. Based on this detection signal El (described later), the start timing of the drum rotation direction and the start timing of conveyance of the recording paper 32 are determined. 37 and 38 are paper feed rollers that feed the recording paper 32. Note that the modulator 23 uses an acousto-optic element that utilizes known acoustic effects.

Conventionally, this type of device has been configured as described above, in which image information, such as character codes and print control data, sent from an external device such as a host computer is once edited page by page for several pages. and stores it in page memory. Image information for one page stored in this page memory is sequentially read out and converted into dot data according to the character code. Next, in accordance with the converted dot data, for example, in a laser beam printer, the laser beam L
A latent image is formed on the photosensitive drum 28 by modulating and controlling B into an on/off signal according to the dot data. Subsequently, the formed latent image is developed with a developer such as toner, the transferred toner image is transferred to a recording medium being conveyed, for example 32, and the toner image transferred to the recording paper 32 is thermally fixed. By outputting the desired image, the desired image is obtained.

Such printers are available with various printing densities depending on the intended use.

The printing density of a printer is expressed in dots per inch (dots per inch), which is usually expressed in terms of the number of printed dots per inch. For example, the printing density is 240D
PI means printing at a density of 240 dots per inch.

[Problem that the invention seeks to solve]

However, the recording density of printers varies depending on the purpose of the user, such as those that require precision such as drawings and circuit diagrams, and those that require less recording density.
For example, there are those used for outputting general documents, and the former has a recording density of 400° and 480 DPI, while the latter has a recording density of 240 DPI.

Furthermore, in America and Europe, 300 DPI printers are used for outputting general documents, and 240 DPI printers are used for outputting Kanji characters.

However, the recording density of a printer is set at the time the printer is shipped, and each printer can only print at its own set recording density.
The printer cannot be used to output Kanji characters, and the user has to purchase a printer for outputting Kanji characters, which is extremely uneconomical.

This invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to obtain a printer control device that can vary the recording density so that a single printer can arbitrarily record from a high-density image to a low-density image. With the goal.

[Means for solving problems]

The printer control device according to the present invention includes a scanning device that scans a recording medium to form an image according to input image information, and a scanning device that interprets a control code input from an external device.
A recording density variable means is provided for varying the recording density by varying the conveyance frequency of image information and the scanning speed of the scanning means.

[Effect]

In this invention, when a control code for varying the recording R density is input from an external device, the recording density variable means varies the main scanning speed of the scanning means and the conveyance frequency of the constructed image information to achieve a predetermined recording. Set density.

〔Example〕

FIG. 1 is a block diagram showing the configuration of a printer control device showing an embodiment of the present invention. The structure will be explained with reference to FIG.

In this figure, reference numeral 1 denotes an input control unit that interfaces text information A consisting of character codes communicated from a host computer. Reference numeral 2 denotes a page memory in which text information A inputted to the input control section 1 sequentially erases previously stored text information A. 3 is a main control section which converts the character code read out from the page memory 2 into dot pattern information B for each character by referring to the character pattern generation section 4, and stores the dot pattern information B in the scan buffer 5. The scan buffer 5 is composed of a first scan buffer 5a, a second scan buffer 5b, etc., and can perform alternate reading and writing in parallel. Reference numeral 6 denotes a readout control unit which, in response to the readout signal C sent from the main control unit 3,
A parallel-to-serial converter 7 reads the dot pattern information B alternately from the first scan buffer 5a or the second scan buffer 5b, and converts it into dot pattern data D read out by the readout control section 6, and then sends the dot pattern information B to an image forming section (not shown). will be sent to. 8 is a flip-flop (hereinafter referred to as F
F) is set by the detection signal El output from the drum rotation position detector 35, and the pulse output F2 is sent to the main controller 3.
Send to. A counter 9 counts the pulse signal E2 output from the beam detector 34 and sends counter data CD to the main controller 3. A selector 10 selects one of the clock generators 1ia to 77d in accordance with a clock selection signal J sent from the main control section 3. The selector 10 outputs the selected carrier frequency signal K to the parallel-to-serial converter 7. Reference numeral 12 denotes a register that holds variable signals sent out by the main control section 3. A D/A converter 13 converts the variable signal held in the register 12 into a D/A converter and outputs a motor speed signal M to a driver (not shown) that drives the motor 25.

Note that the FF 8 is reset by a reset signal G sent by the main control section 3. H is a drum rotation signal, which the main control section 3 sends to a drive system (not shown) that drives the photosensitive drum 28. The main control unit 3 controls the paper feed roller 3 at the conveyance start signal.
7 and 38 to a drive system (not shown).

F2 is a pulse signal output in response to the detection signal El input to the FF8, and is output to the OR circuit OR and the main control section 3. Fl is a pulse signal output from the main control section 3, which is output to the OR circuit OR, and the counter 9 is set by the OR output F3.

Next, the operation will be explained.

Text information A consisting of character codes sent from a host computer or magnetic tape device, etc., which is an external device, is temporarily stored in the page memory 2 by the input control section 1, and then stored in the page memory 2 by the main control section 1. The written text information A is read out in order from the beginning. At the beginning of the text information A is a control code from the postcomputer that specifies the recording density of the printer.

When receiving the control code specifying the recording density, the main control unit 3 decodes the contents and controls the motor 25 according to the specified recording density.
A variable signal is sent to the register 12 to vary the rotational speed, that is, the main scanning speed. Next, the variable signal is D
The /A converter 13 converts the signal into analog information and sends it as a motor speed signal M to the driver of the motor 25 (not shown). The driver changes the rotation speed of the motor 25 according to the voltage of the motor speed signal M. For example, if the value set in the register 12 is increased, the motor speed signal M
Since the voltage increases, the rotation speed of the motor 25 increases, and conversely, if the value set in the register 12 is decreased, the rotation speed of the motor 25 decreases. In addition, the main control unit 3 sets a selection signal J for selecting the carrier frequency of the dot pattern data D in accordance with the recording density specification to the selector]0, and locks an appropriate one of the clock generators 1]a to 11d to the selector 1.
6.0, the clock signal K for conveying the dot pattern data D is selected by the control unit 6. Next, the main controller 3 sends the character code read from the page memory 2 to the character pattern generator 4.
Convert it to character dot pattern B by referring to , and convert this to 1
By repeating the process for each line, information for l scanning lines of the character dot pattern information B is stored in the scan buffer 5. When the dot pattern information is stored in the scan buffer 5, the main control section 3 outputs a drum rotation signal H to a printing section (not shown), so the photosensitive drum 28 starts rotating and is mounted on the disk 36. When the magnet 36a passes the drum rotation position detector 35, it outputs a detection signal El and sets the FF8, so the OR output F3 becomes HIGH. Since the pulse signal F1 is at a LOW level in the printing state, the clear state of the counter 9 is canceled at this point, and the counter 9 receives the detection signal E from the beam detector 34.
Start counting 2. Pulse signal F2 is OR circuit O
Since the readout signal C is sent to the main control unit 3 as well as to the main control unit 3, the readout signal C is outputted to the readout control unit 6, and the dot pattern information B of the scan buffer 5 is output in synchronization with the carrier frequency signal K. Start reading. The dot pattern information B read out in this way is
After being converted into serial data by the serial converter 7 in synchronization with the carrier frequency signal K, the data is sent to a printing section (not shown) and irradiated onto the photosensitive drum 28 as optical information. The main control unit 3 senses the value of the counter 9 and counts the value at which the photosensitive drum 28 rotates and reaches a position where the leading edge of the text information irradiated onto the photosensitive drum 28 and the leading edge of the recording paper 22 coincide. When the value is reached, a conveyance start signal H is output, and the paper feed rollers 27 and 28 rotate in synchronization with this conveyance start signal H, and stop after conveying 221 sheets of recording paper.

When the main control section 3 finishes writing one page's worth of dot pattern information B, it stops the write operation to the scan buffer 5, drops the read signal C, and outputs the reset signal G, so that the FF 8 The counter 9 is cleared accordingly. When the readout signal C falls, the readout control unit 6 stops the readout operation when it finishes reading out the dot pattern information B for one scanning line currently being read out, so the irradiation of the text information onto the photosensitive drum 28 ends. . The photosensitive drum 28 continues to rotate after this, and the magnet 36a on the disk 36 detects the drum rotation position detector 35.
When reaching the position, the detection signal El is output and FF8
The print operation for the next page is started in order to set the page.

FIGS. 2(a) to 2(C) are schematic diagrams showing examples of print output according to the present invention, and FIG. b) shows an enlarged printed character (for example, A) when the rotation speed of the motor 25 is increased without changing the rotation speed of the photosensitive drum 28, and FIG. It shows enlarged printed characters when the carrier frequency signal K of the dot pattern information B is increased.

As can be seen from this figure, if the number of rotations of the motor 25 is increased without changing the number of rotations of the photosensitive drum 28, the result shown in FIG.
As shown in , the recording density in the recording paper transport direction (arrow direction) increases and the printed characters become narrower in the vertical direction. Therefore, in this invention, the transport frequency K of the dot pattern information B is increased and , by increasing the rotation speed of the motor 25, characters with a higher density (see (C) in the same figure) are output compared to normal characters (output characters with a certain fixed recording density (shown in (a) in the same figure)). Note that the rotational speed of the photosensitive drum 28 is usually not changed due to the stability of the printing paper conveyance system and the delicate potential holding characteristics of the photosensitive drum 28.

Note that in the above embodiment, the clock generators 11a to 11b
Although the case has been described in which one type of carrier frequency is selected from among the above, for example, by increasing the number of bits of the selection signal J, the types of clock generators that can be selected can be increased.

Furthermore, it goes without saying that when a control command specifying recording density from a host computer serving as an external device is not applied to text information A, an image is output at a certain fixed recording density.

Further, in the above embodiment, the recording density variable operation in a laser beam printer has been described, but the present invention can also be applied to an inkjet printer or the like. In this case, the same effect can be obtained by varying the feed speed in the main scanning direction of the scanning drive system and the conveyance frequency of the constructed image information.

〔Effect of the invention〕

As explained above, the present invention includes a scanning means that scans a recording medium to form an image according to input image information, and a scanning means that interprets a control code input from the external device.
Since a recording density variable means is provided for varying the recording density by varying the image information conveyance frequency and the scanning speed of the scanning means, it is possible to arbitrarily record from a high density image to a low density image with one printer. Since the recording density can be varied, the versatility of the device is greatly improved, and it has the excellent advantage of being able to significantly improve economic efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a printer control device according to an embodiment of the invention, FIGS. 2(a) to (C) are schematic diagrams showing examples of print output according to the invention, and FIG. 1 is a perspective view of a laser beam printer showing an example of the apparatus. In the figure, ] is an input control section, 2 is a page memory, 3 is a main control section, 4 is a character pattern generation section, 5 is a scan buffer,
6 is a readout control unit, 7 is a parallel-to-serial converter, and 8 is an FF
, 9 is a counter, 10 is a selector, 11a to lid are clock generators, ]2 is a register, and 13 is a D/A converter. X o'clock - 111

Claims (1)

[Claims] A recording device that forms an image based on image information input from an external device, comprising a scanning means that scans a recording medium to form an image according to the input image information, and a control input from the external device. 1. A printer control device comprising a recording density variable means for interpreting a code and varying a conveyance frequency of image information and a scanning speed of the scanning means to vary the recording density.