JP2726314B2 - Video printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video printer capable of printing a hard copy of a screen of a television receiver or the like as a still image.

In other words, the present invention captures a video signal to be displayed on its display surface from a television receiver, a video tape recorder (VTR), a laser disk device, a personal computer, or the like as a still image and creates a hard copy video. It can be said that it relates to a printer.

[Conventional technology]

As a signal processing device in a video printer for color-printing a video image, a signal processing device capable of reducing the frame memory capacity without deteriorating the image quality of the printer is described in JP-A-62-43291. Such are known.

[Problems to be solved by the invention]

However, in this type of conventional video printer, in a printed hard copy, a portion of a blanking period in a horizontal scanning period of a composite video signal, that is, a portion where no effective video exists, is also printed in solid black. As a result, no consideration has been given to the problem that an unsightly screen may be created just like a black frame surrounding an image portion on which a valid video portion is printed.

In general, in a composite video signal, since the length of a blanking period portion in one horizontal scanning period, the length of an effective video signal portion, and the like are determined by a standard, if the composite video signal is in accordance with the standard, Even with conventional video printers that capture and print this, only the valid video signal part is printed without printing during the flyback period, so it is not possible to create a shabby screen that surrounds the image part with a black frame Absent.

However, for example, in a VTR or the like, the ratio between the length of a blanking period in one horizontal scanning period and the length of an effective video signal portion may vary, and a composite video signal that is not in accordance with rules may be handled. If a composite video signal that does not conform to the standard is input to a conventional video printer, the above black frame will be printed if the retrace interval is longer than the standard, and the retrace interval will be shorter than the standard. If the length of the effective video signal portion is longer than that, the black frame is not printed, but a part of the effective video signal portion is not printed instead, resulting in a problem that chipping occurs.

Hereinafter, this will be specifically described with reference to FIG.

FIG. 2 is an explanatory diagram of the relationship between the waveform of the input composite video signal to be printed and its hard copy. In the case of FIG. 9A, the blanking period and the video period within one horizontal scanning period conform to the Radio Law and the standards such as the studio standard EIA and RS170A. If set, no black frame is generated, and the entire image period can be effectively printed.

In the case of FIG. 6B, the blanking period is longer than the standard on the left side of the screen, and when printing is performed with the print area set in FIG. Prints a black frame BL at the left end of the print. Similarly, in the same figure (c), since the blanking period digs into the image period on the right side of the image period, a black frame BL at the right end is generated on the screen.
Since the blanking period penetrates into the video period at both the left and right ends of the video period, black frames are printed at the left and right ends of the screen.

The printing of the black frame may occur not only on the left and right sides of the screen but also on the upper and lower sides (vertical direction) (see FIG. 2E).

Conventionally, if it is attempted to prevent the occurrence of all these black frames in a print area that is uniquely determined, the print area will be set smaller than the effective screen defined by the standard. However, there has been a problem that printing in which the information amount of the input signal is sufficiently expressed cannot be performed.

The object of the present invention is to solve the problems in the prior art, even when a composite video signal that does not conform to the standard is input, without creating an irregular screen surrounded by a black frame around the image portion, It is another object of the present invention to provide a video printer capable of correctly printing a valid video signal portion as a hard copy without excess or shortage without displaying a part of the valid video signal portion.

[Means for solving the problem]

To achieve the above object, according to the present invention, in a video printer, in accordance with an input composite video signal, in a period in which a video signal is present in each horizontal scanning period, the recording head is driven by the head driving means. A print area control means for setting a print area on a hard copy to the head driving means so as not to perform printing in a blanking period in which no video signal is present, and The area control means prepares a memory for storing a predetermined print area for a plurality of types of print areas, inspects an input composite video signal, and determines, during a horizontal scanning period, a period in which a video signal exists and a video signal. Is determined, and an optimum one is selected from the plurality of types of memories according to the determination result. The print area was stored in the memory consisted of means for setting to said head driving means.

Further, in the present invention, the print area control means prepares a memory for storing a predetermined print area for a plurality of types of print areas, and when a composite video signal having a different horizontal scanning frequency is input, It has an auto scan control means for judging a horizontal scanning frequency of a signal and automatically executing a process corresponding to the signal, and selecting an optimum one from the plurality of types of memories according to a judgment result by the auto scan control means. Further, the printing apparatus comprises means for setting the selected print area stored in the memory to the head driving means.

[Action]

The print area control means prepares a memory for storing a predetermined print area for a plurality of types of print areas, inspects the input composite video signal, and determines a period during which the video signal exists in the horizontal scanning period. Discriminating a blanking period in which no signal is present, and selecting an optimum one from the plurality of types of memories according to the discrimination result;
Since the selected print area stored in the memory is set for the head driving unit, a black frame corresponding to a blanking period is not printed, and a valid video period is not lost.

The print area control means prepares a memory for storing a predetermined print area for a plurality of types of print areas, and when a composite video signal having a different horizontal scanning frequency is input, the horizontal scanning frequency of the video signal is adjusted. Has an auto-scan control means for automatically executing a process corresponding thereto, and selecting an optimum memory from the plurality of types of memories in accordance with a result of the discrimination by the auto-scan control means. Since the print area stored in the memory is set for the head driving means, even when a composite video signal having a different horizontal scanning frequency is input, a black frame is not printed and an effective There is no missing video period.

〔Example〕

FIG. 1 is a block diagram conceptually showing a configuration of a video printer as one embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes a video signal (composite video signal)
Input terminal, 110 is a signal processing means, 120 is a synchronization processing means,
130 is a print head driving means, 150 is a print area control means, 160 is an operation means, and 170 is a printing means including a printing mechanism.

Next, the operation will be described. A video signal from an external signal output device (not shown) such as a VTR or a television receiver is input to the input terminal 101. The signal processing means 110 processes the input video signal into a signal suitable for driving the head and outputs the processed signal. For example, if the printing means 170 is a color print, the input composite signal (composite video signal) is
Normally, A / D conversion (analog / digital conversion) is performed in order to decode the signal into a B primary color signal and obtain a signal suitable for input to the head driving means 130. If the input signal is not limited to a still image signal and a moving image signal is also input, an image memory means may be provided here and the moving image signal may be converted into a still image signal using this.

Next, the synchronization processing means 120 separates the synchronization signal from the input video signal to be printed to obtain horizontal and vertical synchronization signals. These horizontal and vertical synchronizing signals are sent to the signal processing means 110 and used for the signal processing, and are also sent to the print area control means 150 via the terminal 152. The print area control unit 150 monitors an output signal from the signal processing unit 110 via a terminal 151 with reference to a synchronization signal from the synchronization processing unit 120 supplied via a terminal 152, and thereby prints an area to be printed. And determine
Output as a print area control signal. The print area control signal is sent to the head driving means 130 via the terminals 155 and 132.

The operation unit 160 gives a desired operation command to the print area control unit 150 and other necessary units.

In the head driving means 130, the print area control means 150
Based on the print area control means sent from
The print area is determined from the signals input from the terminal 131, and the image signal included in the area is output to the print unit 170 after performing the tone control of the print density according to the print unit 170. I do. Printing means 1
At 70, the terminal driving means 130
The image signal transmitted through the printer is printed.

The printing means 170 includes, for example, a printer using a sublimable dye thermal transfer method or an ink jet method. However, it is needless to say that the present invention is applicable to any type of printing.

Next, with reference to FIG. 3, the principle of operation of the conceptual diagram shown in FIG. 1 will be described in detail again.

In the figure, reference numeral 300 denotes a video signal to be printed as an image image, reference numeral 301 denotes a horizontal synchronization signal, reference numeral 302 denotes a horizontal print area signal indicating a print area in the horizontal direction of the screen, reference numeral 30 denotes
Reference numeral 3 denotes a horizontal recording enable / disable content table for explaining the horizontal print area signal 302, 311 denotes a vertical synchronization signal, 312 denotes a vertical print area signal indicating a print area in a screen vertical direction, and 313 denotes a vertical print area signal 312. Table for determining whether or not recording is possible in the vertical direction.

FIG. 3A is an overall view in which a partly broken portion of FIG. 3 is also completely represented, in other words, FIG. 3 is an enlarged view of a main part (upper left part) of FIG. 3A.

In this operation principle, prior to printing, a video signal to be printed is inspected, a print area in which a black frame is not generated is determined, and printing is performed in accordance therewith.

Hereinafter, reference will be made to FIGS. 3 and 3A. In order to set a print area, it is first checked whether the first line from the top of the image plane of the video signal to be printed corresponds to the vertical blanking signal. When the dots are inspected one by one from the left end of the first line of the image 300 based on the horizontal synchronizing signal 301 and the vertical synchronizing signal 311, it can be understood that all of the lines are almost black level and are blanking signals. . Therefore, the first line "0" of the table 313 is written on the assumption that the first line of the vertical print area is a vertical blanking signal so that printing is not performed.

Similarly, it is checked whether the second line from the top of the image 300 is a vertical blanking signal. Then, it can be seen that the second line is a blanking signal for the first dot and the second dot, but is a valid video signal from the third dot.
Therefore, "1", which promises to print on the second line of the vertical print area, is written in the second column of the table 313. In the second line of the image 300, the effective video signal was from the third dot, so when inspecting the third line,
It can be seen that the effective video signal is in the vertical direction and the effective video signal is from the third dot in the horizontal direction.

The results of such an inspection are shown in the table 303 in the horizontal direction and in the table 313 in the vertical direction.
Indicated by "1". From now on, a horizontal print area signal 302 and a vertical print area signal 312 indicating a print area are generated, and if an area slightly smaller than the area indicated by these two signals is set as a print area, a signal to be printed without printing a black frame is formed. Prints that make the most of the effective video period can be obtained.

The above-mentioned inspection for the video signal need not be performed for the entire period of the signal to be printed.
It only needs to be done for the top, bottom, left and right edges of 300, and if it is done for 5% to 10% of each of the upper, lower, left and right of the standard value, the inner central part is determined as the effective video screen Is enough. In addition, when all the inspected periods are determined to be blanking areas, the video signal itself to be printed is considered to be almost black (for example, a screen in which darkness is captured). The set value of the area is the maximum period of the inspection.

The inspection for the video signal described above is the first
In the figure, the print area control means 150
The output is performed by monitoring the output of the signal processing means 110 via the terminal 151 with reference to the horizontal and vertical synchronization signals input from the terminal 151. As a result, the obtained print area signal is output to the terminals 155 and 132. Needless to say, it is supplied as a control signal to the head driving means 130 via the control signal.

FIG. 4 shows the head driving means 13 in the conceptual diagram of FIG.
It is a block diagram which shows one specific example of 0.

4, reference numeral 131 denotes an input terminal for inputting a signal from the signal processing unit 110 shown in FIG. 1, 132 denotes an input terminal for a control signal from the print area control unit 150, and 134 denotes a terminal to the printing unit 170 shown in FIG. A print signal output terminal, 401 is a line memory for temporarily storing a video signal, 403 is a line memory control means, 402 is a gradation control means for controlling the gradation of the output of the line memory for the print density and sending it to the printing means 170. is there.

Next, the operation will be described. The video signal processed by the signal processing unit 110 is temporarily stored in a line memory 401 corresponding to the head of the printing unit 170. Gradation control means 402
Then, the gradation control is given to the signal from the line memory 401, and the printing means 170 is sent through the print signal output terminal 134.
To print. The gradation control means 402 performs gradation control necessary for the system, but performs multi-gradation control from a binary gradation of black and white to, for example, 64 gradations of color.

At this time, the line memory control means 403
Controls writing and reading to 01. Line memory control means 40
3 receives a print area signal from the print area control means 150 via a control signal input terminal 132 as a control signal, controls a video signal to be written to and read from the line memory 401 by the control signal, and controls a period corresponding to blanking. Is controlled to be “white” (not printed).

Therefore, the black signal is not printed on the print image because the video signal sent to the gradation control unit 402 does not already have a black signal in the blanking period that causes the black frame.

FIG. 5 is a block diagram showing a specific configuration example of the print area control means 150 in the conceptual diagram of FIG. 1 as a configuration example useful for understanding the present invention.

5, reference numeral 151 denotes a video signal input terminal from the signal processing means 110 in FIG. 1, 152 denotes a synchronization signal input terminal from the synchronization processing means 120, 501 denotes a video signal sampling means,
02 is a comparison processing means, 503 is a reference level generation means, 504 is a horizontal print area memory means, 505 is a vertical print area memory means, 153 is a control signal input terminal from the operation means 160, 506 is a control means, and 507 is a print area. An output means 155 is a data output terminal for sending print area data to the head driving means 130 in FIG.

Next, the operation will be described. Prior to printing, in order to determine the print area for the video signal, the control of the control means 506 performs the inspection of the video signal as described in FIG. 3 to determine the print area.

The control unit 506 receives horizontal and vertical synchronizing signals of the video signal, and controls each unit based on the signals. The sampling means 501 samples the input video signal and outputs it to the comparing means 502. Comparison means 502
Then, a signal from the reference level generating means 503 is compared with a signal from the sampling means 501 to determine whether or not a blanking period has occurred.

The reference level generating means 503 generates a reference level (substantially a pedestal level) for determining a video period during a blanking period. The determined result is stored in the horizontal print area memory unit 504 and the vertical print area memory output unit 505, and is output from the output terminal 155 to the head drive unit 130 by the print area output unit 507.

In the head driving means 130, the print area control means 150
Since only the video period is printed using the print area signal from the printer, no black frame is printed on the print.

The signal input to the sampling means 501 is a luminance signal obtained by processing the signal processing means 110 accordingly if the printing means 170 at the subsequent stage is a monochrome printer, and a signal corresponding thereto if the printing means 170 is a color printer. Processing means 110
Are obtained by mutually adding the luminance signal or the RGB primary color signal obtained by the above processing. When the RGB signals are added to each other, they may be added at almost the same ratio, and it is not necessary to particularly consider the visibility correction.

The feature of this configuration example is that since the blanking period of the image signal to be printed is detected and the maximum print size is output in a range where the blanking period is not printed, all the information of the image signal can be used for printing.

FIG. 6 shows another specific example of the print area control means.
FIG. 2 is a block diagram showing a configuration example that is useful for understanding the present invention as 0A.

In FIG. 6, 601, 602, and 603 are print area preset memories, 604 is a print area output unit, 155 is a data output terminal, and 153 is a control signal input terminal from the operation unit 160.

Next, the operation will be described. In this example, the print area is stored in advance in a plurality of print area preset memories (601 to 603 in FIG. 6), and any one of them is controlled by a control signal input from the operation unit 160 via the terminal 153. And output from the output terminal 155.

The print area preset memory stores a typical print area signal and a small print area signal in which a black frame is hardly generated. The feature of this example is that a print without a black frame can be obtained with a simple configuration, and is suitable for a simple system or a system in which input signals are fixed to a plurality of known types. In a system having a plurality of input terminals, the switching of the input terminal switching signal and the switching of the print area preset signal are associated with each other so that they can be linked to each other, which makes the system easier to use.

FIG. 7 is a block diagram showing another specific example of the print area control means 150 as a main part of an embodiment of the present invention, as 150B.

In FIG. 7, reference numeral 701 denotes an area selecting means for selecting a print area signal, and 702 denotes a print area output means.

Next, the operation will be described. In the present embodiment, the output of a plurality of pre-stored print area preset memories (601 to 603 in FIG. 7) is compared with the blanking period of the input signal, and the largest print that does not need to print a black frame is performed. An area is selected and output from a plurality of print area preset memories (601 to 603).

The feature of the present embodiment is that the optimum print area is automatically selected from the preset values, and thus the size of the size of the image of the completed print becomes the number of presets (in this example, three types). The size of the image does not unnecessarily vary. It is also possible to manually select a print area preset memory by an operation from the operation means.

FIG. 8 shows the head driving means 13 in the conceptual diagram of FIG.
It is a block diagram showing another specific example of 0 for reference.

In FIG. 8, reference numeral 801 denotes a line memory control unit, and 802, a data control unit. The same parts as those in FIG. 4 are denoted by the same reference numerals.

Next, the operation of this example will be described. The video signal from the signal processing means 110 shown in FIG. 1 is temporarily stored in a line memory 401 corresponding to the head of the printing means 170. The line memory control means 801 controls writing and reading of all input video signals to and from the line memory 401.

The gradation control means 402 controls the gradation of the signal from the line memory. The data control means 802 receives the output from the print area control means 150 and controls the data sent to the printing means 170 to "white" (not print) by this control signal. Since the control signal from the print area control means 150 is a signal that does not print during the blanking period, the resulting print does not have a black frame due to the blanking period.

As an example of the print area control means 150 used in combination with this example, the specific examples described in FIGS. 5, 6, and 7 can be used.

FIG. 9 is a block diagram conceptually showing another embodiment of the present invention suitable for an auto scan video printer.

When printing signals from signal sources with different horizontal and vertical scanning frequencies, such as NTSC television signals and signals for monitor display of personal computers, the printing is automatically followed by the scanning frequency of the signal from the signal source. There is a video printer of the auto scan system that performs the operation. In this embodiment, a print without a black frame can be obtained in conjunction with the automatic scan.

In FIG. 9, reference numeral 901 denotes an input terminal for a television signal; 902, a signal input terminal for a personal computer;
03 is an input switching circuit, 110 is a signal processing means, 920 is a synchronization signal processing means, 930 is an auto scan control means, 130 is a head driving means, 940 is a print area control means, 950 is an operation means, and 170 is a printing means. .

Next, the operation will be described. An external television signal is input from an input terminal 901, and a personal computer signal is input from an input terminal 902. Under the control of the operating means 950, the input switching circuit 903 selects a signal from one of the input terminals. The auto scan control means 930 and the synchronization processing means 920 perform synchronization processing following the input signal. Further, the auto scan control means 930 outputs the result of determination of the synchronization signal frequency band of the input signal to the print area control means 940 and the operation means 950.

Currently, the horizontal frequency of television signals is about 15KHz,
Horizontal frequency of signal for personal computer is 15KH
It can be divided into four groups of synchronous frequency bands centered on z, 24KHz, 31KHz, and 33KHz. The auto scan control means 930 determines which group the signal belongs to. Further, since the input terminals are different between the television signal and the signal for the personal computer, it is possible to determine between the two even at the same 15 KHz.

The print area control means 940 determines a print area based on the type of the input signal and the result of the signal inspection so that a black frame is not printed. The head driving means 130 outputs the output of the signal processing means 110 to the print area control means 9.
The printing means 170 is driven by the control from the output from 40. This makes it possible to obtain a print without a black frame for any signal input from signal sources in a plurality of types of synchronization signal frequency bands.

FIG. 10 is a block diagram showing a specific example of the print area control means 940 in the conceptual diagram of FIG. 9 as a main part of the embodiment of the present invention.

In FIG. 10, reference numeral 943 denotes an input terminal for receiving a determination result of the synchronization signal frequency band from the auto scan control means 930;
Reference numerals 1001 to 1005 denote print area preset memories for synchronization signals of the respective groups, 1006 denotes area selection means, 10
07 is a print area output means, 944 is a control signal input terminal from the operation means 950, and 945 is a print area data output terminal.

Next, the operation will be described. The area selection unit 1006 selects an output of the print area preset memory suitable for the signal input from the determination result of the synchronization signal frequency band from the auto scan control unit 930 and the signal from the operation unit 950. The print area output unit 1007 outputs print area information to an output terminal 945. Since printing is performed using this print area signal, no black frame occurs.

Although not shown in the figure, a method of sampling and inspecting an image signal to be printed as described in FIG. 5 and a method of using a combination of preset values and sampling as shown in FIG. 7 are also effective. is there.

11, 12, 13, 14 and 15,
An example of the procedure for determining the print area described above with reference to FIG. 5 and FIG. 5 is specifically arranged as a flowchart.

FIG. 11 is a schematic flowchart, and FIGS. 12, 13, and
14 and 15 are flowcharts of a subroutine in the chart of FIG.

A schematic flowchart of the main routine in FIG. 11 will be described. 11, 1102 is a subroutine corresponding to FIG. 12, 1103 is a subroutine corresponding to FIG. 13, 1104 is a subroutine corresponding to FIG.
A subroutine corresponding to the drawing, 1105 is a subroutine corresponding to FIG. 15, and 1106 is a process for outputting a print area.

The processing determines a print start line number on the upper end side of the print screen in a subroutine of 1102. Here, the line number corresponds to a scanning line number in the case of a television signal, and is numbered sequentially from the top to the bottom of the print screen. Subsequently, in the subroutine of 1103, the print end scanning line number at the lower end of the print screen is determined. With the above two subroutines, the print area in the vertical direction of the print screen is determined from the print start line number to the print end line number.

In step 1104, the print start dot row number at the left end of the print screen is determined. Here, the dot row number is a number that is obtained by printing the print screen vertically from left to right in a print pixel unit row. In step 1105, the print end dot row number at the right end of the print is determined. As a result, the print area in the print left-right direction is determined from the print start dot row number to the print end dot row number.

In step 1106, the print area set in the above four subroutines is output.

Next, an example of the subroutine 1102 in FIG. 11 will be described with reference to FIG. In processing 1202, the minimum line number to be inspected is set to NUmin, and the maximum line number to be inspected is set to NUmax.
The inspection line number may be about 5% to 10% of the effective signal area of the print signal at the maximum. In the case of the NTSC signal, it may be several lines to several tens of lines from the line where the vertical blanking is completed. N is a line number counter for setting NUmin as an initial value.

At 1203, it is checked whether the Nth line is in a blanking period. In the blanking period, the process proceeds to 1204, and N is incremented by one. If N is larger than NUmax at 1205, the process returns to 1203; otherwise, the process proceeds to 1206. If the Nth line is not in the blanking period in 1203, the process proceeds to 1207 and N is set to Ns.

In 1206, NUmin is set to Ns. Where 1205 to 1206
The setting of NUmin for Ns is because if a valid image is not found within the range planned by the system, it is impossible to distinguish between the blanking period and the video period in the image content (for example, a dark night sky). ,) Are considered to have been entered. In such a case, as described above, the print area is determined so as to be the largest area (NUmin in this case).

When the above processing is completed, the process returns to the main routine of FIG. 11 with the determined print start line number Ns.

An example of the subroutine 1103 in FIG. 11 will be described with reference to FIG. In process 1302, the minimum line number to be inspected at NLmin, N
Set the maximum line number to be inspected in Lmax. Before starting vertical blanking at the bottom of the screen, as in the example of FIG. 12, it is sufficient to inspect several lines to several tens of lines, and NLmax is the line number at which vertical blanking starts, NLmin is NLm
Set a value that is a few lines to tens of lines less than ax. N
Sets NLmax as an initial value with a line counter.

At 1303, it is checked whether the Nth line is in a blanking period. In the blanking period, the process proceeds to 1304 and the counter N is set to-
Do one. At 1305, N and NLmax are compared, and the print end line number NE is determined in the same manner as in the example of FIG. 12, and the process returns to the main routine.

FIG. 14 shows a subroutine for determining the dot row number at the start of the left end printing, and FIG. 15 shows a subroutine for determining the dot row number at the end of the printing on the right end. The dot row numbers are determined as in FIGS. 12 and 13.

The relationship between the print area and the screen image will be described again with reference to FIG. In the figure, 1601 is the largest print area,
Reference numeral 1602 denotes an example of a print area determined according to the present embodiment.

Ns from NUmin to NUmax at the top of the print screen and NLmin to NLm at the bottom at each subroutine
NE from ax, Ms from MLmin to MLmax at the left end,
At the right end, the ME is determined from between MRmin and MRmax. The print area is an area shown by 1602 in FIG. 16 which is surrounded by Ns to NE in the vertical direction of the screen and by Ms to ME in the horizontal direction of the screen.

The determination as to whether or not a certain line or dot row is in the blanking period is performed for each dot as shown in FIG. 3, and the overall determination is performed in consideration of the influence of noise and the like. Alternatively, the determination may be made after adding the values of the dots of one line or one dot row.

〔The invention's effect〕

According to the present invention, it is possible to obtain a print without a black frame generated by printing a blanking period from a composite video signal in which a blanking period varies, and to fully utilize image information of an input signal, It is possible to obtain a print in which a print area is set to fill the entire effective screen without causing loss of image information in a portion near the corner of the print. In addition, since a simple method of selecting a print area so as not to print a black frame from a preset print area is adopted, there is an advantage that an effect can be obtained with a simple configuration.

In addition, even when combined with a signal source having a different scanning frequency, the input image information is fully utilized, in combination with an auto scan method that automatically follows the frequency of the other signal,
In addition, there is an advantage that a print without a black frame can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing one embodiment of the present invention,
FIG. 2 is a view for explaining the reason why a black frame occurs in a hard copy created by a conventional video printer, and FIG.
FIG. 3A is an explanatory view of the principle of operation of the conceptual diagram shown in FIG. 3, and FIG. 3A is an overall view showing the entirety of FIG.
6 are block diagrams showing details of essential parts of the conceptual diagram shown in FIG. 1. FIG. 7 is a block diagram showing a specific example of the print area control means shown in FIG. FIG. 8 is a block diagram showing a specific example of head driving means in the conceptual diagram of FIG. 1 for reference, FIG. 9 is a block diagram conceptually showing another embodiment of the present invention,
FIG. 10 is a block diagram showing a specific example of the print area control means in FIG. 9 as an essential part of the embodiment of the present invention, FIG. 11 is a flowchart showing a procedure for determining a print area,
12 to 15 are flowcharts showing details of the subroutine in the flowchart of FIG. 11, and FIG.
The figure illustrates the relationship between the print area and the screen image. DESCRIPTION OF SYMBOLS 101 ... input terminal, 110 ... signal processing means, 120 ... synchronization processing means, 130 ... head driving means, 150 ... print area control means, 160 ... operation means, 170 ... printing means, 501 ... sampling means, 502 ... comparison processing means,
503... Reference level generating means, 504 horizontal print area memory means, 505... Vertical print area memory means, 507
... print area output means, 601-603 ... print area preset memory means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Kimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (56) References JP-A-63-6978 (JP, A) JP-A-64-40338 (JP, A) JP-A-2-104077 (JP, A)

Claims (2)

(57) [Claims] When a composite video signal is input, a video printer for producing a hard copy of the video signal by driving a recording head by a head driving means in accordance with the video signal and printing the same is provided. Accordingly, the head driving means drives the recording head to perform printing during a period in which a video signal exists in each horizontal scanning period, and performs printing in a retrace period in which no video signal exists. A print area control means for setting a print area on a hard copy to the head drive means so as to prevent the memory from storing a predetermined print area by a plurality of types of print areas. An area is prepared, and the input composite video signal is inspected. Discriminating a period in which a signal is present and a blanking period in which no video signal is present, selecting an optimum one from the plurality of types of memories according to the result of the determination, and selecting a print area stored in the selected memory. A video printer comprising: means for setting the head driving means to the head driving means. 2. A video printer which receives a composite video signal and drives a recording head by means of a head driving means in accordance with the video signal to print the video signal, thereby producing a hard copy of the video signal. Accordingly, during a period in which a video signal exists in each horizontal scanning period, the head driving means drives the recording head to perform printing, and in a blanking period in which no video signal exists, printing is performed. A print area control means for setting a print area on the hard copy to the head drive means so as not to cause the print area to be hardened, and the print area control means comprises a plurality of types of memories for storing a predetermined print area. In addition to preparing the print area, when a composite video signal with a different horizontal scanning frequency is input, It has an auto scan control means for judging the horizontal scanning frequency of the image signal and automatically executing a process corresponding to the horizontal scan frequency. According to the judgment result by the auto scan control means, an optimum one is selected from the plurality of types of memories. A video printer comprising means for selecting and setting a selected print area stored in the memory to the head driving means.