JP2994928B2 - Video printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video printer such as a thermal transfer printer for reading video data and print data from an image memory, outputting a video to a monitor based on the video data, and performing printing based on the print data. It is about.

[0002]

2. Description of the Related Art FIG.
9 through FIG.

FIG. 6 is a block diagram showing an example of a conventional video printer. In FIG. 6, 1 is an image memory,
Reference numeral 2 denotes an image processing circuit for improving the image quality of an image, reference numeral 3 denotes a video output circuit, reference numeral 4 denotes a print data selection circuit for extracting color signal data to be printed, and reference numeral 5 denotes printing for converting print data into transfer data to a thermal head. It is a data processing circuit.

[0004] The operation of the video print constructed as described above will be described with reference to FIG. 7. Now, (n, m) will be referred to as the n-th horizontal pixel number (referred to as a horizontal pixel number n) and the m-th vertical pixel number (n). The description will be made assuming that the pixel data is located at a position of a vertical pixel number m (see FIG. 2).

When the print switch (not shown) is not operated, that is, when the video data stored in the image memory 1 is output on the monitor, and when the monitor is an interlace display, the first field and the second field are used. In this order, video data for monitor output is read from the image memory 1 and image processing is performed by the image processing circuit 2 to increase the image quality of the image, and then a display device (not shown) such as a CRT is displayed by the video processing circuit 3. Output video to

When a print switch (not shown) is turned on, the print data selection circuit 4 sequentially extracts print data from the first field video data and the second field video data based on the vertical synchronization signal. Will do.

That is, in the print data selection circuit 4, among the video data read from the image memory 1 on the basis of the vertical synchronization signal, first, the vertical pixel numbers 1, 3, 5, .., Ie, vertical pixel data (1, 1), (1, 3), (1,
5),... Are sequentially extracted (period A in FIG. 7), and then vertical pixel numbers 2, 4, 6,
, Vertical pixel data (1, 2), (1, 4), (1, 6),
Are sequentially extracted (period B in FIG. 7), and print data # 1 for one vertical line corresponding to the horizontal pixel number 1 is obtained.
This is sent to the printer as print data, and printing for one vertical line is performed.

Next, the following first field image data:
In the same manner as described above, print data # 2 for one vertical line corresponding to horizontal pixel number 2 is obtained from the second field video data, and thereafter, print data #n for one vertical line corresponding to horizontal pixel number n is sequentially obtained. , Print data #N for one vertical line corresponding to the horizontal pixel number N is obtained in order, and print data for the entire screen is obtained.

As described above, in this conventional example, print data # 1, # 2,..., #N for one line corresponding to horizontal pixel numbers 1, 2,. Are simultaneously output simultaneously with the video data.

FIG. 8 is a block diagram showing another example of a conventional video printer. In FIG. 8, reference numeral 11 denotes a dual port memory which is an image memory having two outputs,
Reference numerals 12a and 12b denote an image processing circuit for video data and an image processing circuit for print data, respectively, 13 an image output circuit, and 15 a print data processing circuit.

The operation of the video print constructed as described above will be described with reference to FIG. The video data for monitor output is sequentially read out from the dual port memory 11 in real time, and by controlling the print data to be randomly accessed, the video data and the print data are read out by different systems, and the print data # 1 is read out. , # 2, # 3,..., #N are sequentially output simultaneously with the video data for each video data output frame.

[0012]

However, the conventional video printer whose block diagram is shown in FIG. 6 requires a print data selection circuit 4 for extracting print data from video data, so that the circuit scale is large. Not only becomes large, but also has a problem in that there is a limitation in terms of high-speed printing.

Further, the conventional video printer whose block diagram is shown in FIG. 8 uses a dual port memory having two outputs, which is expensive and requires complicated control. There was a problem of inviting up.

The present invention has been made in view of the above points, and enables transfer of print data with a simple circuit configuration, and realizes high-speed printing and high-quality printing using an inexpensive memory. It is intended to provide a video printer.

[0015]

In order to solve the above-mentioned problems, a video printer according to a first invention of the present application comprises an image memory and a pulse-like image having a period of an integral multiple of a vertical synchronizing signal.
Video data output period based on the output data switching signal
Time and printer data output period
During the period, video data and print data
Reading control means for controlling time-division reading of data
With the door, as well as video output to the monitor based on the video data, meet video printer for printing based on the print data, the data reading system
The control means outputs the same horizontal image during the printer data output period.
The pixel data for one vertical line corresponding to the prime number is
Read from the image memory, and during the video data output period,
Field video data is read from the image memory .

A video printer according to a second invention of the present application is the video printer according to the first invention ,
The data read control means outputs the printer data.
In the power period, the same pixel data is successively written twice for one vertical line.
Is read out .

[0017]

In the video printer according to the first aspect of the present invention, the video data is read out from the image memory during the video data output period and output to the monitor, and during the print data output period, the one corresponding to the same horizontal pixel number from the image memory is output. Since the pixel data for the vertical line is read and transferred, the data processing of the video data and the print data can be performed by time division, and the circuit configuration can be simplified.

In the video printer according to the second aspect of the present invention , the same pixel data is output twice during the print data output period.
Since one vertical line is continuously read and data is transferred, data can be read in field units.
In addition to realizing cost reduction using an inexpensive memory, field interpolation can be easily performed, and high image quality and enlarged printing can be realized.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a video printer according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the video printer of this embodiment has an image memory (RGB memory, luminance / color difference memory, etc.) 21 and an output data switching signal which is pulse-shaped at an integral multiple of the vertical synchronizing signal. Based on the image memory 2
A data read control circuit 22 for controlling the division reading time of data from one image at time series with respect to the division reading <br/> seen out to video data sequence and a print data string when from the image memory 21 An image processing circuit 23 for performing image processing such as high image quality of the image data, and a video output circuit 25 or a print data processing circuit 2
And a changeover switch 24 for changing over the output to No. 6.

The data transfer operation of the video printer having the above-described configuration will be described with reference to FIGS. Assuming that pixels are stored in the image memory 21 as shown in the memory map shown in FIG. 2, the video printer according to the present embodiment uses the timing synchronized with the vertical synchronization signal as shown in FIGS. In step (1), prior to the first field video data, control is performed so that print data for one vertical line to be printed is output in the order of horizontal pixel numbers. In FIG. 4, the horizontal pixel number n
(N = 1 to N) is shown.

That is, during the printing operation period, the output data switching signal is at a low level at a cycle of an integral multiple (twice in this embodiment) of the vertical synchronizing signal, and during the period when the output data switching signal is at a low level. , Print data #
As n, the pixel data (n, m) of the vertical pixel number m corresponding to the horizontal pixel number n is continuously read from the image memory 21 from m = 1 to M. When this reading is completed,
The output data switching signal becomes high level, and the first field video data and the second field video data are read from the image memory 21 in synchronization with the video output timing.

Then, from the print data # 1 to the print data #N, they are sequentially read out in two vertical synchronizing signal periods prior to the first field video data, and when the printing operation is completed, the output data switching signal is automatically and constantly changed. It becomes high level, and the transfer of print data ends.

The video data and print data read out in a time-division manner from the image memory 21 by the data read-out control circuit 22 based on the output data switching signal are input to the image processing circuit 23, and are time-sequentially used to improve the quality of the image. Processing is performed. The image-processed data is converted by a changeover switch 24 into a video data string into a video output circuit 25.
The print data string is input to the print data processing circuit 25.

As described above, according to one embodiment of the video printer of the present invention, image processing of video data and print data by time division can be performed, and the circuit configuration can be simplified. Also, since printer data processing can be performed in the same cycle as the vertical synchronization signal,
Enables high-speed printing.

Next, another embodiment of the video printer of the present invention will be described with reference to FIG.

The video printer according to the present embodiment uses the image memory in the embodiment shown in FIG. 1 as a field memory, the first field video data and the second field video data as the same data, When the pixel data (n, m) of the vertical pixel number m corresponding to the horizontal pixel number n is read from the image memory as the print data prior to the first field video data, the same pixel data of m = 1 is continuously read. Read twice,
Thereafter, similarly, 2 × M data is read in the order of m = 2, 3,. In FIG. 5, the horizontal pixel number n (n = 1)
To N).

That is, during the printing operation period, the output data switching signal becomes a low level in a cycle of an integral multiple (here, twice) of the vertical synchronizing signal, and during the period when the output data switching signal becomes a low level, the printing operation is performed. As data #n, the pixel data (n, m) of the vertical pixel number m corresponding to the horizontal pixel number n is continuously read twice from the image memory from m = 1 to M, respectively. When this reading is completed, the output data switching signal becomes high level,
The field video data and the second field video data are read from the image memory in synchronization with the video output timing.

Therefore, according to another embodiment of the video printer of the present invention, in addition to the functions and effects of the above-described embodiment,
It is possible to reduce the cost by using the field memory, and in the print data processing, it is possible to easily perform the field interpolation, and it is possible to achieve the effect of achieving high image quality and enlargement printing. In the present embodiment, the case where a field memory is used for the purpose of cost reduction has been particularly described. However, it is also possible to read out data in units of fields using a frame memory. Therefore, high image quality and enlarged printing can be realized.

In the above-described embodiment, the reading of the print data string is described as being performed prior to the first field video data. However, the reading is performed prior to each of the first and second field video data. You may do so.

[0031]

Since the video printer according to the first aspect of the present invention has the above-described configuration, the video data is read out from the image memory during the video data output period, output to the monitor, and the video data is output during the print data output period. One vertical line corresponding to the same horizontal pixel number from the image memory
Since the pixel data is read out and transferred, the data processing of the video data and the print data can be performed by time division, and the circuit configuration can be simplified.

In the video printer according to the second aspect of the present invention , the same pixel data is output twice during the print data output period.
Since one vertical line is continuously read and data is transferred, data can be read in field units.
In addition to realizing cost reduction using an inexpensive memory, field interpolation can be easily performed, and high image quality and enlarged printing can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a video printer according to the present invention.

FIG. 2 is a memory map showing a state of storing pixels in an image memory in one embodiment of the video printer of the present invention.

FIG. 3 is a timing chart showing output data in one embodiment of the video printer of the present invention.

FIG. 4 is an enlarged explanatory view of a main part in FIG. 3;

FIG. 5 is a timing chart showing output data in another embodiment of the video printer of the present invention.

FIG. 6 is a block diagram illustrating an example of a conventional video printer.

FIG. 7 is a timing chart showing output data in an example of a conventional video printer.

FIG. 8 is a block diagram showing another example of a conventional video printer.

FIG. 9 is a timing chart showing output data in another example of a conventional video printer.

[Explanation of symbols]

 21 Image Memory 22 Data Readout Control Circuit 23 Image Processing Circuit 24 Changeover Switch 25 Video Output Circuit 26 Print Data Processing Circuit

Claims (2)

(57) [Claims] 1. An image memory, comprising: an output memory which forms a pulse in a cycle of an integral multiple of a vertical synchronization signal;
The video data output period and the printer
The data output period is time-divided, and the above
Time-division reading of video data and print data from image memory
A data readout control means for controlling read-out , a video printer for outputting an image to a monitor based on the image data and performing printing based on the print data , wherein the data readout control means comprises: Data output
During the power period, one vertical line corresponding to the same horizontal pixel number
Pixel data from the image memory.
During the image data output period, the field video data is
A video printer for reading from an image memory . 2. A video printer according to claim 1, wherein said data reading control means includes means for outputting said printer data.
In the power period, the same pixel data is successively written twice for one vertical line.
A video printer characterized in that it reads out data for each video.