JP3030051B2 - Video printer - Google Patents

Description

The present invention relates to a video printer.

(B) Conventional technology For example, the magazine “TV Technology”, September 1989, PP.15-PP.27
Discloses a sublimation type thermal transfer video printer. In such a video printer, an image signal of one field or one frame is stored in a memory, and the image signal stored in the memory is read out, displayed on a monitor television, and printed. Printing is performed line by line in the direction perpendicular to the scanning line direction (scanning direction).

As described above, as a method of printing one line at a time in the vertical direction with respect to the scanning line, the direction of reading data from the memory for displaying an image is different from the direction of reading data for printing. However, in such a case, a complicated read control circuit or an expensive dual-port memory must be used.

For this reason, the data is read out from the memory only for displaying the image, and at the time of printing, one line in the vertical direction necessary for printing next from the data read out only for displaying the image. There is a method of picking up the data, storing the data separately in a memory, and printing the line when the data for one line is completed.

(C) Problems to be Solved by the Invention In the latter method, in the case of an NTSC video signal, to read one line of data in the vertical direction, it takes about 16 mm for an image for one field. It takes about 33 milliseconds for an image for one second and one frame.

For this reason, assuming that one screen is composed of 620 lines in the vertical direction with respect to the scanning lines, it takes 33 × 620 × 3 ≒ 61 (seconds) to print one frame of a color image, and the paper feed time If this is included, it takes a considerably long time from the start of printing.

Therefore, the present invention aims to shorten the printing time.

(D) Means for Solving the Problems The video printer of the present invention divides one screen of video signal information in time and stores it in a plurality of memories, and simultaneously prints data from the plurality of memories at the time of printing. A plurality of print data aligned in the vertical direction with respect to the scanning line are obtained within one horizontal period, and the print data is accumulated for one line and printed.

(E) Operation According to the above configuration, data can be obtained simultaneously from a plurality of memories in which video signals for one screen are stored within one horizontal period.

(F) Embodiment One embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows a schematic block diagram of a video printer embodying the present invention, the input video signal (V _i), the brightness by YUV conversion circuit (1) (Y) and color difference (R-Y, B-
Y) The signal is separated into signals and converted into digital data by the A / D converter (2). The luminance / color difference signals thus converted into digital data are written into two field memories (3a) and (3b). At this time, the memory control circuit (11) firstly operates the first field memory (3a). When the writing of the odd field data to the memory (3a) is completed, control is performed so that the even field data is written to the second field memory (3b).

In order to reproduce the image signals written in the first and second field memories (3a) and (3b) on a monitor television (not shown), the memory control circuit (11) operates the first and second field memories (3a). And (3b) both are simultaneously in the read mode, and the first and second field memories (3a) and (3b)
The image signal of the field is supplied to the data selector (4), and one of the first and second field memories (3a) and (3b) is alternately selected for each vertical period to perform D / A.
The data selector (4) is controlled so as to be provided to the converter (5). Then, the luminance and color difference signals output from the D / A converter (5) are converted into a composite video signal by the NTSC encoder (6) and output to the monitor television.

On the other hand, at the time of printing, image data read out for image display from the first and second field memories (3a) and (3b) is first latched at the following timing by the latch circuit (7a).
Latch at (7b). That is, as described above, printing is performed one line at a time in a direction perpendicular to the scanning lines. This will be described with reference to the schematic diagram of FIG. FIG. 2 (a) is a schematic diagram of the first and second field memories, and FIG. 2 (b) is a composite diagram of the first and second field memories. One vertical line is indicated by the line xx '. And the x
Taking the case of printing the line indicated by the -x 'line as an example, when data at point A is read from the first field memory (3a) for image display, the memory control circuit (1
1) controls the data latch circuit (7a) and causes the latch circuit (7a) to hold the data at the point A. At this time, at the same time or with a time error of less than one horizontal period, data from the second field memory (3b) on the scanning line adjacent to the point A and at the point B on the winning xx 'line The data is controlled by the memory control circuit (11) so that the data is read out, and the data at the point B is held in the latch circuit (7b).

Incidentally, when the data at the point B is read for display, the data at the point A is obtained in the same manner.

The data held by the data latch circuits (7a) and (7b) is taken in by a printing control circuit (8) composed of a microcomputer or the like and stored in a one-line memory (9). As described above, two data (data of the first and second field memories) are obtained in one horizontal period. By repeating such an operation for one field period (one vertical period), the first line memory (9) stores the first data. X-
Data indicated by black dots (line data for one frame) is stored on the x 'line. The data on the line xx '(line data for one frame) is stored in the one-line memory (9).
When all are stored, they are sent to the printing head (10) to be printed.

In the above embodiment, a frame still image is recorded using two field memories.
Field still image recording can be performed using n memories having a field capacity, or frame still image recording can be performed using 2n memories having a 1 / n field capacity.

(G) Effects of the Invention As described above, according to the present invention, it is possible to obtain data necessary for printing at high speed with a simple configuration without requiring a complicated memory control circuit.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a video printer embodying the present invention, and FIG. 2 is a diagram for explaining the operation of the video printer embodying the present invention. (3a) (3b)... First and second field memories, (4)
... data selector, (7a) (7b) ... data latch circuit, (8) ... printing control circuit, (9) ... one line memory, (10) ... printing head.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/76 H04N 5/91-5/956

Claims (1)

(57) [Claims] A YUV converter for separating a video signal into a luminance signal and a color difference signal; an A / D converter for converting an analog signal into a digital signal; A first and a second field memory, and a line memory for storing at least one line of data in a direction perpendicular to a scanning line in one frame of a video signal, and The A / D converter converts the separated luminance signal and chrominance signal into digital data while separating the separated luminance signal and chrominance signal into digital data. In the first and second field memories, data on a vertical line from the first and second field memories with respect to a scanning line is synchronized during one horizontal synchronization. At the same time, the data is read out and stored in the line memory, and is printed when one line of data is accumulated.
A video printer which prints an image of one frame of a video signal by sequentially printing each line of data in a scanning line direction.