JPH07237319A - Nonimpact printer - Google Patents

Abstract

PURPOSE:To reduce a processing time in printing a character having a highlighted outline part, a character having a highlighted outline part and a modified inner part, or the like. CONSTITUTION:A title printer comprises a data conversion circuit 20 provided with a boundary detection circuit part 21 detecting a boundary data signal of a bit map signal (a) in the scanning direction and supplying the boundary data signal to a light emitting element as a real printing data signal (f), a pattern generation circuit part 22 generating a specific pattern signal, and a gate circuit part 23 supplying the specific pattern signal to the light emitting element as a real printing data signal (g) only in the presence of the bit map data signal (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-impact printer.

[0002]

2. Description of the Related Art Conventionally, in a non-impact printer such as an electrophotographic printer, a charged photosensitive drum is irradiated with a light source to form an electrostatic latent image on its surface, and toner is attached to the electrostatic latent image. Then, development is performed to form a toner image, and the toner image formed there is transferred and fixed on a sheet.

FIG. 9 is a block diagram of a printer section control circuit in a conventional non-impact printer. In FIG. 9, reference numeral 1 denotes a print control unit including a microprocessor, a ROM, an input / output port, a timer, etc. This is provided inside the printer printing unit and controlled by a host device (for example, a personal computer) not shown. The entire printer unit is sequence-controlled by a signal, a video signal, etc., and a printing operation is executed. When the print instruction is received by the above-mentioned control signal, the print control unit 1 first detects, via the fixing device temperature sensor 4, whether or not the fixing device 3 having the heater 2 is within a usable temperature range. Heater 2 if not in temperature range
Is turned on, and the fixing device 3 is heated to a usable temperature. Next, the developing / transferring process motor (PM) 5 is rotated via the driver 6, and at the same time, the charging high voltage power supply 7 is turned on to charge the developing device 8.

Subsequently, the type of the set sheet is detected by the sheet remaining amount sensor 9 and the sheet size sensor 10, and the sheet feeding corresponding to the sheet is started. Here, the paper feed motor (PM) 11 can rotate in both directions via the driver 12, and is first rotated in the reverse direction to preset the set paper until the paper inlet sensor 13 detects it. Feed only a certain amount, then rotate forward,
The paper is conveyed into the printing mechanism inside the printer.

The print control unit 1 sends a timing signal to the host device and receives a video signal when the paper reaches the printable position. The video signal edited by the host device for each page and received by the print control unit 1 is used as a bitmap data signal by the LED head 1
4 is transmitted. At this time, the print control unit 1 also transmits a clock signal for transmitting the bitmap data signal to the LED head 14. Then, when the print control unit 1 receives the video signal for one line, the print control unit 1 transmits a latch signal to the LED head 14 and sends a bit map data signal to the LED head 1.
Hold in 4 Further, the print control unit 1 transmits a print drive signal to the LED head 14 to execute the print processing corresponding to the bitmap data signal before receiving the next data from the higher-level device.

Here, the transmission and reception of the above-mentioned video signal is
It is performed for each print line. Further, the information printed by the LED head 14 is made into a latent image as a dot having an increased potential on the photosensitive drum charged with a negative potential. Then, the image forming toner charged to a negative potential is attracted to each dot by an electric attraction force, and thereby a toner image is formed on the photosensitive drum. After that, the toner image is sent to the transfer portion, and at the same time, the high voltage power supply 15 for transfer having a positive potential is turned on by the transfer signal, and the transfer device 16 transfers the toner image onto the sheet passing through the gap between the photosensitive drum. . The sheet on which the toner image is transferred in this manner is conveyed while being in contact with the fixing device 3. As a result, the toner image is fixed on the sheet by the heating action of the fixing device 3. Further, the paper on which the toner image is fixed passes through the paper discharge port sensor 17 from the printing mechanism of the printer and is discharged to the outside of the printer.

[0007]

However, in the above-mentioned conventional non-impact printer, when printing characters and the like, the font built in the ROM or the like of the host device is expanded and modified inside the host device, Since the print control unit 1 creates a bitmap data signal to be printed on the basis of this, for example, when emphasizing a contour portion such as a character for printing, the print data received from the higher-level device is used as a basis. Draw outlines (outer frame) of characters etc. on the print control unit 1,
It is necessary to perform processing such as filling the inside, and when emphasizing the outline of characters etc. and modifying the inside, it is necessary to distinguish between the filled area and the non-filled area when filling. As a result, it takes a long processing time until the printed paper is ejected.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and expands print data received from a higher-level device into a bit map data signal, and charges latent data corresponding to the bit map data signal. In a non-impact printer that forms an image on a photosensitive drum by irradiating light from a light emitting element, a boundary data signal in the scanning direction of a bitmap data signal is detected and this boundary data signal is supplied to the light emitting element as an actual print data signal. Configuration comprising a data conversion circuit having boundary detection means, pattern generation means for generating a specific pattern signal, and gate means for supplying the specific pattern signal to the light emitting element as an actual print data signal only when there is a bitmap data signal Has become.

[0009]

In the non-impact printer of the present invention,
The boundary data signal in the scanning direction of the bit map data signal is detected by the boundary detecting means, and the detected boundary data signal is supplied to the light emitting element as an actual print data signal. The specific pattern signal generated by the pattern generating means is supplied to the light emitting element as the actual print data signal by the gate means only when there is the bitmap data signal.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the present embodiment, the same components as those in the above-mentioned conventional example are designated by the same reference numerals, and duplicated description will be omitted. FIG. 1 is a block diagram showing an example of the configuration of a data conversion circuit according to the present invention, and FIG. 2 is a block diagram of a printer control circuit according to the present invention. First,
In FIG. 2, each component indicated by reference numerals 1 to 17 is as described in the conventional example. In this embodiment,
A data conversion circuit 20 is provided between the print control unit 1 and the LED head (light emitting element) 14, and the data conversion circuit 20 is developed based on print data received from a host device (not shown). Bitmap data signal (a),
Clock (CK) that gives a time reference for data transmission and reception
The signal (b) and the timing signal (c) generated each time print data for one line is received from the host device are input from the print control unit 1.

As shown in FIG. 1, the data conversion circuit 20 generally includes a boundary detection circuit section 21, a pattern generation circuit section 22 and a gate circuit section 23. First, the structure of the boundary detection circuit unit 21 will be described.
The bitmap data signal (a) supplied from the D-type flip-flop (hereinafter, simply referred to as a flip-flop)
24 D (data) inputs. Flip flop 24
Becomes the D (data) input of the flip-flop 25, and the Q output of the flip-flop 25 becomes the D (data) input of the flip-flop 26. Further, the clock signal (b) output from the print control unit 1 is input to each of the flip-flops 24, 25, and 26.

On the other hand, the Q output of the flip-flop 25 is input to one input terminal of the AND circuit 27, and the Q _N output (inverted signal of the Q output) of the flip-flop 24 is input to the other input terminal. Further, the Q _N output of the flip-flop 26 is input to one input end of the AND circuit 28, and the Q output of the flip-flop 25 is input to the other input end. Further, the output of the AND circuit 27 is input to one input end of the OR circuit 29, and the output of the AND circuit 28 is input to the other input end.

Next, the pattern generating circuit section 22 will be described. This is the first counter 30 which is the first measuring section.
And a second counter 31, which is a second measuring unit, and a pattern generating unit 32, which generates a specific pattern signal. First, the clock signal (b) is input to the first counter 30, and the timing signal (c) is input to the second counter 31. As a result, the first counter 30 measures the clock signal (b) and supplies the measured value to the pattern generation unit 32, and the second counter 31 measures the timing signal (c) and outputs the measured value to the pattern generation unit. Give to 32. The pattern generation unit 32 is composed of, for example, a logic circuit, specifies the print position based on the measurement values given from the first counter 30 and the second counter 31, and a specific pattern signal corresponding to the specified print position. To generate.

The gate circuit section 23 includes, for example, an AND circuit 3
The AND circuit 33 has one input terminal to which the Q output of the flip-flop 25 is input and the other input terminal to which the output of the pattern generating circuit section 22 (pattern generating section 31) is input. It

Further, the output of the boundary detection circuit section 21 (OR circuit 29) is at one input terminal of the OR circuit 34, and the gate circuit section 23 (AND circuit 33) is at the other input terminal.
The outputs of the OR circuits 34 are transferred to the LED head 14 which is a light emitting element.

The operation of the non-impact printer of this embodiment will be described next. First, when the control signal (d) and the video signal (e) are received from a host device such as a personal computer, the print control unit 1 develops the print data received from the host device into a bitmap data signal (a) based on the control signal (d) and the video signal (e). Then, this is supplied to the data conversion circuit 20. FIG. 3 shows an example of a character pattern developed in the bitmap data signal (a) by the print control unit 1. In the example shown in the figure, the bit data in which the character “A” is indicated by a “●” mark is shown. Are displayed in a matrix.

FIG. 4 is a time chart showing the operation of the data conversion circuit 20 when converting the data of the uppermost pattern of the character pattern shown in FIG. First, when the bitmap data signal (a) is received from the print control unit 1, the Q outputs of the flip-flops 24, 25 and 26 sequentially rise to the Hi level in synchronization with the clock signal (b). At this time, the Q of the flip-flop 24
_{When both the N} output and the Q output of the flip-flop 25 become the Hi level, the output signal of the AND circuit 27 rises to the Hi level, and the Q output of the flip-flop 25 and the Q _N output of the flip-flop 26 both become the Hi level. Then, the output signal of the AND circuit 28 rises to the Hi level. The output signal of the OR circuit 29 is the AND circuit 2
When the output signal of 7 becomes Hi level or the output signal of the AND circuit 28 becomes Hi level, it rises to Hi level.

Here, the output signal of the OR circuit 29 is a boundary data signal in the scanning direction (arrow direction in FIG. 3) of the original character pattern, and this boundary data signal is the boundary as the actual print data signal (f). It is supplied from the detection circuit unit 21 to the LED head 14 via the OR circuit 34. FIG. 5 shows an output pattern in the case where the printing process is performed based on the actual print data signal (f) transmitted from the boundary detection circuit unit 21, and at this time, only the outline portion of the original character pattern is marked with “●”. It is displayed with a bit pattern indicated by, whereby only the outline of the character "A" is emphasized.

On the other hand, in the pattern generation circuit section 22, the first counter 30 measures the clock signal (b) for detecting the boundary data signal, and the second counter 31 measures the timing signal (c) for line feed. Measures. Then, in the pattern generation unit 32, the first counter 30 and the second counter 30
The print position is specified based on the measurement value of the counter 31, and a specific pattern signal corresponding to the print position is generated and output to the gate circuit unit 23.

In response to this, in the gate circuit section 23, when both the Q output of the flip-flop 25 and the output of the pattern generating circuit section 22 are at the Hi level, the output signal of the AND circuit 33 rises to the Hi level and this is output. The LED head 1 as an actual print data signal (g) via the OR circuit 34.
Supply to 4. That is, the gate circuit unit 23 supplies the specific pattern signal given from the pattern generation circuit unit 22 to the LED head 14 as the actual print data signal (g) only when the bitmap data signal (a) is present.

FIG. 6 is a diagram in which the character pattern based on the boundary data signal and the mask pattern based on the specific pattern signal are superimposed, and in the actual printing process, the actual print data signal (g) supplied from the gate circuit unit 23. As a result, dots are printed at the printing position indicated by the "◆" mark in the figure. By the way, in the mask pattern shown in FIG.
As an example, a case where the dot generation rate of the mask pattern by the specific pattern signal is set to 25% as shown by the dot-shaped cells in the figure is shown.

Accordingly, the actual print data signal ((f) + (g)) is supplied from the data conversion circuit 20 to the LED head 14, and the charge corresponding to the actual print data signal ((f) + (g)) is supplied. When a latent image is formed on the photosensitive drum by light irradiation from the LED head 14 and a predetermined printing process is performed,
The original character pattern shown in FIG. 3 is printed as an output pattern shown in FIG. In the print output pattern shown in FIG. 7, the outline of the character "A" is emphasized, and the inside of the outline is modified according to the dot arrangement of the specific pattern signal.

In the above description of the embodiment, the case where the dot generation rate of the mask pattern by the specific pattern signal is set to 25% is taken as an example, but the setting of the dot generation rate in the pattern generation section 32 is changed as appropriate. By doing
The inside of the outline portion of the character pattern can be modified in various forms. FIG. 8 shows a case where the dot occurrence rate of the mask pattern by the specific pattern signal is set to 50%, and in this case, an arrangement different from the arrangement of “♦” shown in FIG. Dot printing is performed at the printing position of "◆", and the inside of the outline portion of the character "A" is modified.

Further, in the configuration of this embodiment, the print controller 1
Although the pattern conversion circuit 20 is provided between the LED head 14 and the LED head 14, the present invention is not limited to this. For example, the pattern conversion circuit 20 can be incorporated inside the LED head 14 which is a light emitting element.

Further, in this embodiment, the first counter 30 which is the first measuring means and the second counter 30 which is the second measuring means.
Pattern generator 3 including counter 31 and logic circuit
The pattern generation circuit section 22 can be easily configured only by combining three digital circuits such as 2.

[0026]

As described above, according to the present invention,
By detecting the boundary data signal in the scanning direction of the bitmap data signal and supplying the boundary data signal to the light emitting element as the actual print data signal, processing equivalent to normal processing (processing that does not require emphasis or modification) By emphasizing the outline portion of the character to be printed in time, it is possible to print the specific pattern signal generated by the pattern generating means to the light emitting element as an actual print data signal only when there is a bitmap data signal. It becomes possible to modify the inside of the outline portion of the character to be printed and perform printing in the same processing time as the normal processing. As a result, it is possible to significantly reduce the processing time when emphasizing the outline portion of a character or modifying the inside of the outline portion and printing.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a data conversion circuit according to the present invention.

FIG. 2 is a block diagram of a printer control circuit according to the present invention.

FIG. 3 is a diagram showing an example of a character pattern.

FIG. 4 is a time chart showing the operation of the data conversion circuit.

FIG. 5 is a diagram showing an output pattern according to a boundary data signal.

FIG. 6 is a diagram in which patterns are overlapped with each other.

FIG. 7 is a diagram showing a print pattern based on an actual print data signal.

FIG. 8 is a diagram illustrating another specific pattern.

FIG. 9 is a block diagram of a printer control circuit in a conventional example.

[Explanation of symbols]

 20 data conversion circuit 21 boundary detection circuit section (boundary detection means) 22 pattern generation circuit section (pattern generation means) 23 gate circuit section (gate means) 30 first counter (first measurement means) 31 second counter (second) Measuring means) 32 pattern generator

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Claims (2)

[Claims] 1. A non-impact printer in which print data received from a higher-level device is developed into a bitmap data signal and a charge latent image corresponding to the bitmap data signal is formed on a photosensitive drum by light irradiation from a light emitting element. A boundary detecting means for detecting a boundary data signal in the scanning direction of the bitmap data signal and supplying the boundary data signal to the light emitting element as an actual print data signal; a pattern generating means for generating a specific pattern signal; A non-impact printer comprising a data conversion circuit having a gate means for supplying the specific pattern signal to the light emitting element as an actual print data signal only when there is a bitmap data signal. 2. The pattern generating means includes a first measuring section for measuring a clock signal for detecting the boundary data signal, a second measuring section for measuring a line feed timing signal, and the first measuring section. And a pattern generation unit that generates a specific pattern signal corresponding to the print position based on the measurement value obtained by the second measurement unit. Non-impact printer.