JPH0839843A - Video printer - Google Patents

Abstract

PURPOSE:To sufficiently accomplish the cost reduction in a melt-type thermal transfer printer using a serial head. CONSTITUTION:A memory means 11 capable of storing the image data corresponding to a video signal corresponding to one screen, a pattern forming means 12a forming a dot pattern from the video signal stored in the memory means 11, a printing means 31 performing printing on the basis of the dot pattern formed by the pattern forming means 12a and a control means 10 storing image data in the memory means 11 on the basis of the image fetching command from an image fetching command issuing means 34 and forming a dot pattern on the basis of the printing command from a printing command means 34 by the pattern forming means 12a and performing printing on the basis of the dot pattern by the printing means 31 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video printer which prints a video image based on an externally supplied video signal.

[0002]

2. Description of the Related Art A video signal supplied from a tuner or a video device, or a video signal supplied from a computer game machine is taken into a storage medium such as a frame memory at a desired timing, and the video stored in this storage medium is taken. A video printer that prints a still image based on a signal is known (see, for example, Japanese Patent Laid-Open Nos. 2-65390 and 2-298194).

As a method of printing a color still image by a video printer, a sublimation type thermal transfer printer capable of developing full-color (for example, about 16 million colors) dots (pixels) forming an image, and each dot Is composed of dot patterns (sometimes called dither patterns) of three primary colors (for example, Y = yellow, M = magenta, C = cyan), and a fusion type thermal transfer printer that performs color printing by combining these dot patterns is there. The sublimation type thermal transfer printer can print with high image quality, but has a problem that the running cost is high and special paper is required. On the other hand, the fusion type thermal transfer printer has a low running cost and can print on plain paper, but in order to realize full color, it is necessary to increase the resolution of the dot pattern (the density of small dots forming the dot pattern). Therefore, the sublimation type thermal transfer printer is applied to an application that enables high quality printing at a high price, and the fusion type thermal transfer printer is applied to an application that does not require high quality printing at a low price.

From the viewpoint of print dots for printing, a method of scanning a wide print head (line head) corresponding to the paper width in the paper length direction and a relatively narrow print head (serial head). There is a method of scanning the sheet in the width direction of the sheet multiple times. The line head method enables high-speed printing, but requires an expensive head. On the other hand, in the method using the serial head, the cost of the head itself can be suppressed, but the scanning distance of the head becomes long and it is difficult to realize high-speed printing.

From the above, it can be seen that a fusion-type thermal transfer printer using a serial head is advantageous for realizing a low-cost video printer.

[0006]

In order to further reduce the cost of the fusion type thermal transfer printer using the serial head described above, Reduction of memory capacity (prepare the minimum memory) 2. It is preferable to consider suppression of CPU performance (control that does not require a high-performance CPU).

1. In order to realize, printing work must be done in real time. This printing operation includes the above-mentioned dither pattern generation operation. In the conventional fusion type thermal transfer printer, this dither pattern generation work is C
It was realized by software on PU. However, a high-performance CPU is required to realize the dither pattern in real time, and the above-mentioned 2. Is contrary to.

A first object of the present invention is to provide a video printer capable of sufficiently reducing the cost. A second object of the present invention is to provide a video printer capable of externally issuing a print command and the like.

[0009]

The invention according to claim 1 of the present invention is applied to a video printer for printing a color video image with a dot pattern of a plurality of primary colors based on a color video signal supplied from the outside. . Further, the above-mentioned object is achieved by a storage means capable of storing image data corresponding to a video signal for one screen, a pattern forming means for forming a dot pattern from the video signal stored in the storage means, and a pattern forming means. A printing unit that performs printing with the formed dot pattern, and image data is stored in the storage unit based on an image capture instruction from the image capture instruction unit, and a dot pattern is formed by the pattern formation unit based on the print instruction from the print instruction unit. And a control means for performing printing by the printing means by this dot pattern.

The printing means may be provided with a paper feed mechanism for feeding the paper in one direction and a print head for scanning the paper in a direction substantially orthogonal to the paper feed direction. Further, the image data for one screen is read out from the storage means, image processing is performed,
Image processing means for writing the image data subjected to the image processing to the storage means may be provided. Further, when a print control start signal from the outside is input, control means for controlling the printing means based on the print control signal from the outside may be provided.
In this case, the control means may cause the printing means to perform printing based on the image data from the outside.

[0011]

[Action]

-Claim 1-Image data is fetched into the storage means based on the image fetching instruction from the image fetching instruction means, and a dot pattern is formed by the pattern forming means based on the print instruction from the print instructing means. The printing means prints.

(Claim 2) The printing means performs the printing operation by feeding the paper in one direction by the paper feeding mechanism and scanning the print head in a direction substantially orthogonal to the paper feeding direction of the paper.

-Claim 3-The printing means performs the printing operation based on the image data which has already been subjected to the image processing by the image processing means and stored in the storage means.

When the print control start signal is input from the outside, the control means controls the printing means based on the print control signal from the outside. Therefore, printing can be performed using the print control means by appropriately inputting the print control means.

-Claim 5- The control means prints by the printing means based on image data from the outside. In this case, printing based on the video signal is not performed, but printing is performed using image data from the outside.

Embodiments of the present invention will now be described in detail with reference to the drawings. First Embodiment FIG. 1 is a block diagram showing a schematic circuit configuration of a video printer which is a first embodiment of the present invention. In this figure,
Reference numeral 10 denotes a CPU, which has, in addition to an arithmetic processing circuit, a ROM that stores a control program and the like described later, a RAM that temporarily stores the arithmetic result, and an I / O circuit with a peripheral circuit.

Reference numeral 11 denotes a RAM, which has a capacity capable of storing image data corresponding to one frame or one field of video signal corresponding to one screen. More specifically, since the video printer according to the present embodiment is configured to perform printing based on the NTSC video signal, the luminance signal Y and the color difference signal RY for each pixel (dot) forming one screen. , BY are capable of storing a predetermined number of bits.

Reference numeral 12 denotes a controller, which controls the transfer of data to and from the RAM 11 based on a command from the CPU 10. The controller 12 of this embodiment includes a dither pattern generator 12a, and the dither pattern generator 12a.
Generates a dot pattern for printing (dither pattern) using the image data stored in the RAM 11 based on a command from the CPU 10. Although the dither pattern generator 12a and the dither pattern generation method are well known, detailed description thereof will be omitted. However, in the present embodiment, the dither pattern data itself is stored in the ROM of the CPU 10 side, and at the time of dither pattern generation. Data is read from the ROM and the dither pattern generator 12a generates a dither pattern. This enables high-speed processing of data.

Reference numeral 20 denotes a VIDEO IN terminal, which is connected to an external television tuner, a video device or the like to input an NTSC system video signal. Reference numeral 21 is a relay, which connects the VIDEO IN terminal 20 to the color difference decoder 23 to be described later via the A terminal when the printer power is on, and will be described later via the B terminal when the printer power is off. Connect to terminal B of relay 29.

Reference numeral 23 denotes a color difference decoder which extracts a luminance signal Y, color difference signals RY and BY, and a composite SYNC (sync) signal from the video signal and outputs them in parallel. The luminance signal Y, the color difference signals RY, and BY are input to the A / D converter 24, which will be described later, and the composite SYNC signal is input to the controller 12.
Reference numeral 24 denotes an A / D converter, which clamps the luminance signal Y or the like to a DC potential that matches its dynamic range, and then, based on the switching signals SY, SR, and SB from the controller 12, luminance signal Y and color difference signal R-. A / D conversion is performed on Y and BY. The result of A / D conversion is input to the controller 12.

Reference numeral 26 denotes a D / A converter, which D / A converts the digital luminance signal Y and the digital color difference signals RY and BY supplied from the controller 12. The color difference encoder 27 has a luminance signal Y supplied from the D / A converter 26,
An NTSC video signal is generated based on the color difference signals RY and BY and the composite SYNC signal supplied from the controller 12. Reference numeral 28 denotes an output video switch, which outputs the color difference encoder 27 or A of the relay 21 based on the video switching signal from the controller 12.
The video signal from the terminal is output alternatively. Reference numeral 29 denotes a relay, which outputs the VIDEO OUT terminal 30 through the A terminal when the printer power is turned on.
8 is connected to the B terminal of the relay 21 via the B terminal when the printer power is off.

A printer mechanism 31 performs color printing on a sheet (not shown) based on data from the controller 12 or the CPU 10. Printer mechanism 3 of this embodiment
1 is a fusion type thermal transfer printer mechanism using a so-called serial head (head extending in the paper length direction),
Color printing is performed on the paper with the dither pattern generated by the dither pattern generator 12a described above. In this embodiment, color printing is performed with three primary colors of Y (yellow), M (magenta), and C (cyan).

The printer mechanism 31 includes a PE sensor 32 and an LF sensor 33. The PE sensor 32 is a sensor that is turned on when the front end of the paper is loaded in the printer mechanism 31, and the LF sensor 33 is a sensor that is turned on when the paper is fed by one line. Which sensor 32, 3
The detection result of 3 is also sent to the CPU 10. A print switch 34 is turned on when a print button (not shown) is operated. In this embodiment, the print switch has both functions of an image capture command and a print command. A cancel switch 35 is turned on when a cancel button (not shown) is operated.

Next, the operation of the video printer of this embodiment will be described with reference to the flow charts of FIG. 1 and FIGS.

First, when the power supply of the video printer is off, the relays 21 and 29 are connected to the B terminals, and the video signal input to the VIDEO IN terminal 20 is input to the B terminals of the relays 21 and 29, respectively. VIDEO OUT
It is output to the terminal 30. Thus, even when the power of the video printer is turned off, the video signal passes through the video printer, and a video image can be displayed by connecting a video signal display such as a television to the VIDEO OUT terminal 30.

When a power switch (not shown) is operated to turn on the power of the video printer, the relays 21 and 29 are respectively connected to the terminals A, and the VIDEO IN terminal 20, the color difference decoder 23, and the VIDEO OUT terminal 30 are output. 2 to 4 as well as being connected to the respective video switches 28.
Execution of the program shown in the flowchart of FIG.

In step S1, the output video switch 28 is switched by the video switching signal from the controller 12, and the video signal input to the VIDEO IN terminal 20 is output from the B terminal of the relay 21 to the output video switch 28.
Is output to the VIDEO OUT terminal 30 via. Therefore, in this state, the video signal is passing through the video printer.

In step S2, it waits until the print switch 34 is turned on. When the print switch 34 is turned on, the process proceeds to step S3. In step S3, the CPU 10 instructs the controller 12 to load digital image data corresponding to one frame of video signal into the RAM 11. The controller 12 receiving the instruction from the CPU 10 sends the switching signal SY to the A / D converter 23,
SR and SB are sequentially transmitted, and the A / D converter 24 sequentially outputs the luminance signal Y, the color difference signals RY and BY which have passed through the color difference decoder 23 in accordance with the switching signals SY, SR and SB. D
It is converted and transmitted to the controller 12. Then, the controller 12 monitors the composite SYNC signal sent from the color difference decoder 23 and stores digital image data for one frame in the RAM 11. In step S4, the controller 12 waits until the video signal fetching operation by the controller 12 is completed, and the process proceeds to step S5.

In step S5, the output video switch 28 is switched by the video switching signal from the controller 12, and the VIDEO OUT terminal 30 is connected to the color difference encoder 27 side. Next, in step S6, the controller 12 sends the digital image data for one frame in the RAM 11 to the D / A converter 26 and also supplies the composite SYNC signal to the color difference encoder 27 in response to a command from the CPU 10. RAM from the color difference encoder 27
The video signal for one frame taken in 11 is output and output to the outside through the VIDEO OUT terminal 30. Therefore, if a video signal display such as a television is connected to the VIDEO OUT terminal 30, a still image, which is the result of loading the RAM 11, can be displayed.

In step S7, it is determined whether the cancel switch 35 is turned on, and the cancel switch 3
If No. 5 is turned on, the process returns to step S1, and if it is off, the process proceeds to step S8. In step S8, it is determined whether the print switch 34 is turned on. If the print switch 34 is turned on, the process proceeds to step S9, and if the print switch 34 is off, the process returns to step S7.
As a result, even after the print switch 34 is once turned on and the digital image data is loaded into the RAM 11, the state before the image loading can be restored again by turning on the cancel switch 35. Then, when the print switch 34 is turned on again with the digital image data taken in, the printing operation from step S9 is executed.

In step S9, the output video switch 28 is switched by the video switching signal from the controller 12, and the video signal is again fed from the VIDEO IN terminal 20 to VIDE.
It is passed to the O OUT terminal 30. Then, step S1
At 0, the digital image data in the RAM 11 is read out based on a command from the CPU 10 and sent to the CPU 10. The CPU 10 performs contour enhancement processing on the sent digital image data and returns the result to the RAM 11 via the controller 12 again.

In step S11, the digital image data in the RAM 11 is read out based on the instruction from the CPU 10 and sent to the CPU 10. The CPU 10 performs data conversion processing on the sent digital image data. This is because the digital image data stored in the RAM 11 is RGB data, whereas the color printing is performed with the YMC3 primary colors, so it is necessary to perform data conversion based on a known relational expression. . Next, in step S12, a gamma (γ) correction process is performed on the data-converted digital image, and step S1
In 3, the black and white enhancement processing is performed on the gamma-corrected digital image data, and the result is returned to the RAM 11 again via the controller 12.

In each of the processes of steps S10 to S13, digital image data corresponding to pixels in a predetermined area is required to perform the edge enhancement process, so that the digital image data for one screen is used as a unit of data. Processing is performed. For other processes, data processing is performed in pixel units. Since these processes are already known, detailed description will be omitted.

In step S14, the printer mechanism 31 performs a fixed amount of paper feeding operation based on a command from the CPU 10. Next, in step S15, the detection signal of the PE sensor 32 built in the printer mechanism 31 is monitored, and if the PE sensor 32 is in the off state, step S14.
Returning to step S16, when the PE sensor 32 is turned on, step S16 is performed.
Proceed to. In this way, the paper is fed until the leading edge of the paper is loaded into the printer mechanism 31.

In step S16, a fixed amount of paper is fed by the printer mechanism 31 based on a command from the CPU 10. In step S17, it is determined whether the paper has been fed to the print start position, and the paper is fed. If not, the process returns to step S16, and if the paper is fed, step S16.
Proceed to 18. In this way, the paper is fed until it reaches the print start position.

In step S18, based on a command from the CPU 10, the controller 12 causes the Y component of the digital image data in the RAM 11 (this data has already undergone data conversion and the like) to cross the scanning line. It is read and sent to the CPU 10. The CPU 10 creates a so-called dither pattern based on the digital image data and sequentially sends it to the printer mechanism 31. Printer mechanism 3
1 prints the Y component on the paper with this dither pattern. When the print head finishes printing the Y component for one line, the process proceeds to step S19 to print the M component for one line, and further proceeds to step S20 to print the C component for one line. .

The details of the one-line printing in steps S18 to S20 are shown in the flowchart of FIG. First, in step S51, the print head of the printer mechanism 31 moves to the scanning start position in response to an instruction from the CPU 10, and in step S52, the color data (Y, M or C) is read from the RAM 11. In step S53, the data is written in the dither pattern generator 12a built in the controller 12, and the dither pattern corresponding to the data is generated. In step S54, the dither pattern is read from the dither pattern generator 12a. In step S55, the read dither pattern is directly sent from the controller 12 to the printer mechanism 31, and the printer mechanism 31 prints according to this dither pattern. In step S56, it is determined whether or not the printing for one line is completed. When the printing for one line is completed, the process returns to the flowchart of FIG. 4, and if not yet, the process returns to step S52 to sequentially read the data from the RAM 11, The printing operation is performed.

Returning to FIG. 4, in step S21, it is determined whether or not the printing for one screen is completed. If the printing for one screen is completed, the process proceeds to step S22. If not, the process proceeds to step S24. move on.

In step S22, the printer mechanism 31 feeds a fixed amount of paper loaded therein by an instruction from the CPU 10, and in step S23, the PE sensor 32 is fed.
The CPU 10 monitors the detection signal from the PE sensor 32.
If is turned on, the process returns to step S2, and the PE sensor 3
If 2 is turned off, the process returns to step S22. In this way, the paper on which the printing of the color image for one screen is completed is ejected from the printer mechanism 31.

On the other hand, in step S24, the printer mechanism 31 feeds a fixed amount of paper in the printer mechanism 31 in accordance with an instruction from the CPU 10, and in step S25, the LF sensor 33 determines the amount of paper feed performed in step S24. To detect. Then, in step S26, steps S18-
It is determined whether or not one line has been fed from the print position in S20, and if one line has been fed, step S1
Returning to step 8, printing of the next line is started, and when one line is not reached, the process returns to step S24 to continue the paper feeding operation.

As described above, the video signal input from the VIDEO IN terminal 20 is taken into the RAM 11 and printed on the paper as a color image. Here, in the present embodiment, the dither pattern generator 12 is provided in the controller 12.
a is provided, and R is set without going through the CPU 10 during the printing operation.
The dither pattern generator 12a generates a dither pattern based on the image data read from the AM 11, and the dither pattern is sent to the printer mechanism 31 to perform the printing operation. The dither pattern generation operation itself is sufficiently faster than the head moving speed of the printer mechanism 31, etc., and real-time processing is possible. On the other hand, CPU1
0 only needs to issue an operation command to the controller 12 (and the built-in dither pattern generator 12a).
Since it is not necessary for the U10 side to perform the dither pattern generation operation, a heavy load is not imposed on the processing of the CPU 10. As described above, according to the present embodiment, the memory capacity can be minimized and the CPU performance can be suppressed, and the cost of the video printer can be sufficiently reduced.

Further, in the present embodiment, when a print start command is issued, the CPU operates on the digital image data in the RAM 11.
Image processing is performed by 10, and the result is temporarily stored in the RAM 1
Since the digital image data that has been subjected to the image processing is transferred to the printer mechanism 31 all at once after being returned to 1,
The printing operation can be performed at high speed. That is, in the conventional video printer, the image processing circuit is connected between the frame memory and the printer mechanism, and the data from the frame memory is sent to the printer mechanism through the image processing circuit. The printing speed is substantially determined by the speed, and in some cases, the printing operation must be performed at a speed lower than the printing speed of the printer mechanism 31. On the other hand, in this embodiment, since the image processing is performed prior to the data transfer to the printer mechanism, the printing speed is substantially dependent on the data transfer speed from the RAM 11 to the printer mechanism 31 and the speed of the mechanism unit of the printer mechanism 31. The printer mechanism 31 can determine the maximum printing speed and print at the highest speed.

-Second Embodiment- FIG. 5 is a diagram showing a video printer which is a second embodiment of the present invention, and is a diagram showing a connection state with an external device.

The schematic structure of the video printer of this embodiment is similar to that shown in FIG.
Control terminals not used in the examples (hereinafter, C
A terminal 40, which is abbreviated as a terminal, is shown as a C terminal in FIG. 1). The C terminal has a plurality of input / output terminals and is connected to the CPU 10 via a bus line.

As shown in FIG. 5, the C terminal 40 of the video printer of this embodiment is connected to the image forming device 42 via a cable 41. Image creating device 42 shown in FIG.
Is an image input unit such as a tablet, an image data creation unit that creates image data based on an image input from the image input unit, and a printing operation on the video printer of the present embodiment by the image data created by the image data creation unit. It is equipped with a control unit for performing.

Next, the operation of the video printer of this embodiment will be described with reference to the flow charts shown in FIGS. 5 and 6 to 7.

First, when the power supply of the video printer is off, the relays 21 and 29 are connected to the B terminals, respectively, and the video signal input to the VIDEO IN terminal 20 is input to the B terminals of the relays 21 and 29, respectively. VIDEO OUT
It is output to the terminal 30.

When a power switch (not shown) is operated and the power of the video printer is turned on, the relays 21 and 29 are respectively connected to the terminals A, and the VIDEO IN terminal 20, the color difference decoder 23, and the VIDEO OUT terminal 30 are output. 6 to 7 as well as being connected to the respective video switches 28.
Execution of the program shown in the flowchart of FIG.

In step S31, the output video switch 28 is activated by the video switching signal from the controller 12.
The video signal input to the VIDEO IN terminal 20 after being switched from the B terminal of the relay 21 to the output video switch 2
It is output to the VIDEO OUT terminal 30 via 8. Therefore,
In this state, the video signal is passing through the video printer.

In step S32, it is determined whether or not a control start command signal is input from the control unit of the image forming apparatus 42 via the C terminal 40, and if it is input, step S32 is executed.
If not, the process proceeds to step S33. In step S33, it is determined whether the print switch 34 is turned on. If it is turned on, the process proceeds to step S3 in FIG. 2, and if it is turned off, step S32 is performed.
Return to. In this way, when the control start command signal is output from the image creating device 42, the printing operation is performed under the control of the image creating device 42, which will be described later, and when the print switch 34 is turned on, the same as in the first embodiment described above. The printing operation is performed under the control of the video printer itself.

In step S34, it is determined whether or not a cueing command signal has been input from the control unit of the image forming apparatus 42. If it has been input, the process proceeds to step S35, and if it has not been input, the process proceeds to step S36. Step S
In FIG. 3, the cueing operation is executed, the details of which are shown in FIG.
Since it is the same as steps S14 and S15 of, the description thereof is omitted.

In step S36, it is determined whether or not the paper feed command signal is input from the control unit of the image forming apparatus 42. If it is input, the process proceeds to step S37, and if it is not input, the process proceeds to step S38. Step S
At 37, the CPU 10 outputs to the printer mechanism 31 a command to feed a fixed amount of paper loaded in the printer.

In step S38, it is determined whether or not the one-line feed command signal has been input from the control unit of the image forming apparatus 42. If it has been input, the process proceeds to step S39, and if it has not been input, the process proceeds to step S40. . In step S39, the CPU 10 outputs a paper feed command to the printer mechanism 31 while monitoring the detection signal of the LF sensor 33, and feeds the paper by one line. The details are the same as steps S24 to S26 in FIG.

In step S40, it is determined whether or not a ribbon cueing command signal has been input from the control unit of the image forming device 42. If it has been input, the process proceeds to step S41.
If not input, the process proceeds to step S42. In step S41, the CPU 10 instructs the printer mechanism 31 to wind up the printing ribbon contained in the printer mechanism 31 to the beginning of the Y color.

In step S42, it is determined whether or not the one-line print command signal is input from the control unit of the image forming apparatus 42. If it is input, the process proceeds to step S43, and if it is not input, the process proceeds to step S44. . In step S43, the one-line printing operation is executed. Specifically, 1
After sending the line print command signal, the image creating device 42 sends the image data of either the Y component, the M component, or the C component, and the CPU 10 takes in the image data via the C terminal 40. The captured image data is the controller 12
It is stored in the RAM 11 via. Then, when the image data for one row is stored in the RAM 11, the CPU
Reference numeral 10 sequentially reads the image data of the Y component, the M component, or the C component for one line from the RAM 11, and prints on the paper. 1
When the printing of the lines is completed, the CPU 10 causes the printer mechanism 3
Send a command to 1 to wind up the printing ribbon to the beginning of the next color.

In step S44, it is determined whether or not the discharge command signal is input from the control unit of the image forming apparatus 42. If it is input, the process proceeds to step S45, and if it is not input, the process returns to step S34. Step S45
Then, the CPU 10 monitors the detection signal from the PE sensor 32 and performs the paper feeding operation until the paper is ejected from the printer mechanism 31. For details, see steps S22 to S in FIG.
The description is omitted because it is similar to 23.

Therefore, according to this embodiment, in addition to the printing operation under the control of the printer itself, the printing operation under the control of the control unit of the image forming apparatus 42 can be performed.

The details of the video printer of the present invention are not limited to the above-mentioned embodiments, and various modifications are possible.

[0058]

As described in detail above, according to the first aspect of the invention, a pattern for forming a dot pattern from a video signal stored in the storage means is provided separately from the control means for controlling the entire printer. Since the forming means is provided, the capacity of the storage means can be minimized and the performance of the control means can be suppressed, and the cost of the video printer can be sufficiently reduced.

Further, according to the third aspect of the invention, when the print control signal is input from the outside, the printing means is controlled based on the print control signal from the outside, so that the printer is controlled by the external control signal. Control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a video printer which is a first embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the video printer of the first embodiment.

FIG. 3 is a flowchart following FIG.

FIG. 4 is a flowchart following FIG. 3;

FIG. 5 is a diagram showing a video printer which is a second embodiment of the present invention and is a perspective view showing a connection state with an image forming apparatus.

FIG. 6 is a flowchart for explaining the operation of the video printer of the second embodiment.

FIG. 7 is a flowchart following FIG.

FIG. 8 is a flowchart illustrating details of one-line printing.

[Explanation of symbols]

 10 CPU 11 RAM 12 Controller 12a Dither Pattern Generator 20 VIDEO IN Terminal 30 VIDEO OUT Terminal 31 Printer Mechanism 34 Printing Switch 40 Control Terminal

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04N 5/91 H04N 5/91 H

Claims (5)

[Claims] 1. A video printer for printing a color video image by a dot pattern of a plurality of primary colors based on a color video signal supplied from the outside, and a memory capable of storing image data corresponding to one screen of the video signal. Means; pattern forming means for forming the dot pattern from the video signal stored in the storage means;
Printing means for printing with the dot pattern formed by the pattern forming means ;; the image data is taken into the storage means based on an image fetching instruction from the image fetching instructing means; and based on the printing instruction from the print instructing means And a control means for forming the dot pattern by the pattern forming means and performing printing by the printing means by the dot pattern. 2. The video printer according to claim 1, wherein the printing means comprises a paper feed mechanism for feeding the paper in one direction, and a print head for scanning the paper in a direction substantially orthogonal to the paper feed direction. And a video printer characterized by having. 3. The video printer according to claim 1 or 2, wherein: one screen of image data is read from the storage means, subjected to image processing, and the image processed image data is written into the storage means. A video printer comprising image processing means. 4. The video printer according to claim 1, wherein when a print control start signal from the outside is input, the control means controls the printing means based on the print control signal from the outside. A video printer characterized by having. 5. The video printer according to claim 4, wherein the control means causes the printing means to perform printing based on the image data from the outside.