JPS63114458A - Printing controller for image printer - Google Patents

Abstract

PURPOSE:To minimize the power consumption of an image printer and to reduce the capacity of a power source by reducing black data included in data corresponding to a solid black original image in an image memory if image data that an image detection part detects corresponds to the solid black original image. CONSTITUTION:If an original image 2 is black and solid or the image detection part 1 is troubled, a detection signal from a solid black image detection part 10 continues during a period T that a timer 11 sets. Then the output of an AND between the detection signal form the black solid image detection part 10 and a time-up signal from the timer 11 shows up, and a control signal is outputted to the image memory 3 from an image memory control part 13. Hence the ratio of the black data accounting for the data corresponding to the number of solid black scan lines set in the image memory 3 decreases, and image data as is found decreased is transmitted to a printer 5. It prints images having reduced black picture elements rather than its original (images printed by dots and lines and images of half tone, for instance). Thus the capacity of the power source in the image printer can be reduced.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention decomposes an original image into a plurality of black and white pixels, such as an electronic whiteboard or facsimile, and temporarily stores it in an image memory as binary black and white data. The present invention relates to an image printer in which a control unit reads out the contents of an image memory and causes the printer to print the contents.

[Prior Art] Conventionally, this type of image printer has been constructed as shown in FIG. In this figure, (1) is an image detection unit that decomposes an original image (2) into black and white pixels along a plurality of scanning lines scanned in a fixed order, and detects the pixels as binary black and white data. The black and white data detected by the image detection section (1) is temporarily stored in the image memory (3), and then the content of the image memory (3) is read out by a control signal from the printer control section (4), and the original image ( The printer (5) was configured to print an image corresponding to 2). (6) is a printer power supply section that supplies predetermined power to the printer (5).

[Problems to be Solved by the Invention] However, in the conventional image printer shown in FIG.
When the original image (2) is divided into black and white pixels along multiple scanning lines scanned in a fixed order, the proportion of black pixels in one scanning line is greater than the set value A% (for example, 50%). For a black solid original image that is solid and has a continuous black solid scanning line for a set number B (for example, 10), do not take any special measures and treat it as a normal original. Since the capacity of the printer power supply unit (6) was determined in consideration of electric power, it was necessary to provide a printer power supply unit (6) with a larger capacity than necessary for the black solid original image, so the printer power supply unit (6) However, there was a problem in that it became larger than necessary, leading to an increase in cost. For example, a thermal printer that prints on A4 size paper requires a printer power supply unit of approximately 3001+1, taking into account the power required to print a solid black original image. In addition, if the detected data ends up being a solid black original image due to a burnout of the fluorescent lamp in the image detection unit (1) or a failure of the contact image sensor, the printer (5) The problem was that because images were being printed, power was wasted.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the power capacity of an image printer.

[Means for Solving the Problems] The present invention includes an image detection unit that decomposes an original image into black and white pixels along a plurality of scanning lines scanned in a fixed order and detects the pixels as binary black and white data; It includes an image memory that stores detection data of an image detection section, a printer control section that reads out the contents of this image memory and causes a printer to print an image corresponding to the original image, and a printer power supply section that supplies power to the printer. In an image printer comprising: a black solid detection method, the black solid detection method sequentially detects for each scanning line whether or not the black pixel ratio in each scanning line is larger than a set value based on the detection data of the image detection unit; Department and.

A timer is set and reset depending on the presence or absence of the detection signal of the black solid detection section, and outputs a time-up signal after a set time corresponding to a set number of black solid scanning lines has elapsed; and an image memory control unit that reduces the proportion of black data in the data corresponding to the set number of black solid scanning lines in the image memory based on an AND output with a time-up signal. It is.

[Operation] When the original image is not a solid black original image, there is no AND output between the detection signal of the black solid detection section and the time-up signal of the timer, so no control signal is output from the image memory control section to the image memory. Therefore, the black and white data in one image memory is sent as is to the printer, and the printer prints an image corresponding to the original image. If the detection signal from the black solid detection section continues for the timer set time T because the original image is a solid black original or the image detection section malfunctions, the AND of the detection signal of the black solid detection section and the time-up signal of the timer is generated. An output appears, and a control signal is output from the image memory controller to the image memory. As a result, the ratio of black data in the data corresponding to the set number of solid black scanning lines in the image memory decreases, and the image data with this decreased black data is sent to the printer, and the printer processes the black pixels from the original black solid image. An image (for example, a dotted line printed image or a halftone printed image) is printed.

[Example 1] Figure 1 shows an example in which the present invention is applied to an electronic blackboard. The same parts as in FIG. 3 are given the same reference numerals. In Figure 1, (1) is an image detection unit that decomposes an original drawing (2) drawn on a blackboard into black and white pixels along a plurality of scanning lines scanned in a fixed order and detects them as binary black and white data. It is. An image memory (3) is provided on the output side of the image detection section (1).
and a black solid detection section (10) are combined. The black solid detection section (10) is.

Based on the detection data of the image detection unit (1), sequentially detects for each scanning line whether the proportion of black pixels in each scanning line is solid black or not, which is larger than a set value A% (for example, 50%). Then H
, L signal. Specifically, the black solid detection unit (lO) is as follows.

The black pixel "1" in the detection data of the image detection unit (1) (for example, serial data in which black pixels are set to "1" and white pixels are set to "0") is detected every scanning line (for example, the number of pixels is 540). It consists of a counter that counts, a comparator that compares whether the count number of this counter is larger than a set value (for example, 270), and a retrigger type one-shot multivibrator that is triggered by the output of this comparator. , select an appropriate setting time for this one-shot multivibrator (for example, a time slightly longer than one scanning time), and when the black solid scanning line continues for a set number B, continue the H signal for at least B scanning times. is configured to print. A printer (5) such as a thermal printer or a wire dot printer is connected to the output side of the image memory (3) via a printer control section (4).

(6) is a printer power supply section that supplies power to the printer (5). The output side of the black solid detection unit (10) is set (triggered) and reset depending on the presence or absence (H, L) of a black solid detection signal, and is set (triggered) and reset to correspond to a set number B (for example, 10) of black solid scanning lines. A timer (11) is coupled to output a time-up signal after a set time T has elapsed, and an AND circuit (12) is coupled to the output side of this timer (11) and the output side of the black solid detection section (10). .

The set value A% (for example, 50%) and the set number B (for example, 10) (corresponding to the set time T) are used to set the criteria for whether or not the original image (2) is regarded as a black solid original image. For example, the timer (11) is set in consideration of the supply limit time of additional power supply current that can be supplied by taking into account the charge capacity accumulated in the internal capacitor without increasing the power supply capacity of the printer power supply unit (6) itself. Set the set time T (corresponding to the set number B). (13) is an image memory control unit, and this image memory control unit (13) controls a continuous set number B corresponding to the black solid original image in the image memory (3) based on the output of the AND circuit (12). The black data in the data corresponding to each of the black solid scanning lines is changed to white data at predetermined intervals.

Next, the operation of the embodiment described above will be explained with reference to FIG. 2.

(b) First, we will explain when the original is not a solid black original.

When the original image (2) is decomposed into black and white pixels along multiple scanning lines scanned in a fixed order, the proportion of black pixels included in each scanning line is equal to or higher than the set value A% (for example, 50%). If the number of consecutive black solid scanning lines is equal to or greater than the set number B (for example, 10), it is a black solid original image, and if it does not reach the set number, it is set as not a black solid original image. Therefore, as shown in Figure 2 (a), during the T1 time (corresponding to 4 black solid scanning lines) from t1 to t2, t3
The black solid detection unit ( Even if a black solid detection signal is output from 1. , the timer (11) is set (triggered) at 15:00.

At the falling edge of t21 t41 t, the timer (11
) will be reset. Therefore, as shown in FIG. 2(b), the timer (11) does not output a time-up signal, and the output side of the AND circuit (12) remains at the L level, and the image memory ) control signal is not output.

Therefore, the image data consisting of black and white data sent from the image detection section (1) to the image memory (3) and stored is directly transferred to the printer (5) by the printer control section (4).
An image with a black print density corresponding to the original image is printed.

(b) Next, we will explain what happens when the original image is solid black. In the case of a black solid original image, the number of black solid scanning lines is more than the consecutive set number B (for example, 10), so as shown in Figure 2 (a), from time t7, the timer (11) is set for more than the set time T. A black solid detection signal is output from the black solid detection unit (10) until the time elapses. Therefore, as shown in FIG. 5B, the timer (11) outputs a time-up signal at t5, when the set time T has elapsed since t7.

At times, the output side of the AND circuit (12) changes from L level to H level. Therefore, a control signal is output from the image memory control unit (13) to the image memory (3), and the image detection unit (1
) Among the image data sent from and stored in the image memory (3), the black data in the data corresponding to each of 10 or more continuous black solid scanning lines is changed to white data at predetermined intervals ( "1" is cleared to "0")
, Therefore, the printer (5) that prints the contents of the image memory (3) prints the following information for each scanning line of the black solid original image:
Since an image in which black pixels are thinned out at predetermined intervals is printed, a solid black original image is printed as a dotted line image with reduced black printing density, and the power consumption required for image printing is reduced. Therefore, the power capacity of the printer power supply section (6) can be reduced.

In addition, the fluorescent lamp in the image detection unit (1) may burn out or malfunction.
Even in the case where the contact image sensor malfunctions and the black solid detection unit (10) outputs a continuous black solid detection signal for a set time T or more, the operation is almost the same as described above, and the halftone image is Print.

In the above embodiment, the image memory control section generates a set number of consecutive black solid scanning lines corresponding to the black solid original image in the image memory based on the AND output of the detection signal of the black solid detection section and the time-up signal of the timer. The black data in the data corresponding to each of the data is changed to white data at predetermined intervals to print a solid black original image with dotted lines, but the present invention is not limited to this, and the present invention is not limited to this. Any method may be used as long as the proportion of black data in the data corresponding to a set number of solid black scanning lines in the image memory is reduced so that the print image for the solid black original image is printed with a reduced black print density. For example, based on the AND output, the black data in the data corresponding to the black solid scanning line at a predetermined interval (for example, one line interval) out of the set number of black solid scanning lines corresponding to the black solid original image in the image memory is The data may be changed to halftone printing of a print image for a black solid original image. For example, in the case of one-line spacing, the even-numbered scanning lines of the 10 solid black scanning lines corresponding to the black solid original image are the black pixels in the data (
For example, when changing all pixels (e.g. "1") to white pixels (e.g. rOJ) and printing odd-numbered solid black scanning lines, the capacitor in the printer's power supply section is discharged to replenish the lack of power capacity, and even pixels If this capacitor is charged during the th scanning line (when the print data is all white pixels (0) and no printing is performed), there is no need to increase the power supply capacity. Also, based on AND output, all the black data in the data corresponding to the set number of black solid scanning lines corresponding to the black solid original image in the image memory is changed to white data, and the print image for the black solid original image is printed in white. You can also use it as

In the above embodiment, a case has been described in which the present invention is applied to an electronic blackboard, but the present invention is not limited to this, and can also be applied to image printer application equipment such as a facsimile.

[Effects of the Invention] As described above, in the print control device for an image printer according to the present invention, the original image is a solid black original image, or the image detection unit malfunctions, and the image data detected by the image detection unit is a black solid original image. The printer is configured to reduce the black data in the data corresponding to the black solid original image in the image memory when the black solid original image corresponds to That is, an image with reduced black printing density (for example, an image of dotted line printing or halftone printing) is printed. Therefore, compared to the conventional example in which a black solid original image is directly used as a printed image, the power consumption of the image printer can be reduced, and the power supply capacity can be reduced. Therefore, it is possible to downsize the printer power supply section of the image printer and to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of a print control device for an image printer according to the present invention, FIG. 2 is a timing chart showing the operation of FIG. 1, and FIG. 3 is a block diagram of a conventional example. (1)...Image detection unit, (2)...Original image, (3)...
...Image memory, (4)...Printer control unit, (5)
...Printer, (6) ...Printer power supply section, (10
)...Black solid detection unit, (11)...Timer, (12
)...AND circuit, (13)...image memory control section.

Claims (4)

[Claims] (1) An image detection unit that separates the original image into black and white pixels along multiple scanning lines scanned in a fixed order and detects it as binary black and white data, and an image memory that stores the detected data of this image detection unit an image printer comprising: a printer control unit that reads the contents of the image memory and causes the printer to print an image corresponding to the original image; and a printer power supply unit that supplies power to the printer; A black solid detection unit that sequentially detects for each scanning line whether or not the ratio of black pixels in each scanning line is solid black based on the detection data of , and the detection signal of this black solid detection unit. a timer that is set and reset depending on the presence or absence of the black solid scanning line, and outputs a time-up signal after a set time corresponding to a set number of black solid scanning lines has elapsed; and an AND output of the detection signal of the black solid detection section and the time-up signal of the timer. and an image memory control unit that reduces the proportion of black data in the data corresponding to the set number of black solid scanning lines in the image memory based on the following. (2) The image memory control unit, based on the AND output of the detection signal of the black solid detection unit and the time-up signal of the timer,
A patent for changing black data in data corresponding to solid black scanning lines at predetermined intervals among a set number of solid black scanning lines in an image memory to white data, thereby converting a printed image to a black solid original image into halftone printing. A print control device for an image printer according to claim 1. (3) The image memory control unit, based on the AND output of the detection signal of the black solid detection unit and the time-up signal of the timer,
Claim 1 recited in claim 1, wherein the black data in the data corresponding to each of a set number of solid black scanning lines in the image memory is changed to white data at predetermined intervals so that the printed image for the black solid original image is printed as dotted lines. Print control device for image printers. (4) The image memory control unit, based on the AND output of the detection signal of the black solid detection unit and the time-up signal of the timer,
Printing by the image printer according to claim 1, in which the black data in the data corresponding to a set number of black solid scanning lines in the image memory is changed to white data, so that the printed image for the black solid original image is printed as white. Control device.