JPS63267561A - Video printer - Google Patents

Abstract

PURPOSE:To prepare a printing image laterally reversed, by providing a means by which an order of a line of picture element data to be read out from an image memory is reversed. CONSTITUTION:A control signal C3 becomes '0' by normal mode in read out time and becomes '1' by lateral reversion mode when a lateral reversion button is depressed. A controller 22B has an up/down counter, and generates a column address signal which increases as A1, A2,...Am when the control signal C3 is '0' in read out time. In that case, picture element data are read out line by line, starting from the first line A1 to the mth line Am. However, when the control signal C3 becomes '1' in read out time, the controller 22B generates a column address signal which decreases as Am, A2, A1. In that case, the picture element data are read out line by line, starting from the mth line Am to the first line A1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a video printer that prints television images, and is particularly devised so that the left and right sides of the printed image can be reversed.

(Prior Art) A video printer is a printer that creates a hard copy of a television image, and can record a desired image in a fixed manner like a photograph.

Referring to FIG. 5, signal processing in a conventional video printer will be schematically explained.

When printing one frame of a television image 100 as shown in FIG. 5(A), the video signal of that frame is digitized and stored in the frame memory 100 as pixel data.
2 (FIG. 5B). frame memory 10
Each row of 2 corresponds to a horizontal scan line of the television image 100, and pixel data is written in an order corresponding to the rask scan.

Next, pixel data is read line by line starting from the first column of frame memory 102 and latched into line buffer 104 (FIG. 5C). Next, the a-th pixel data of each column is read out from the line buffer 104 at a predetermined timing.

a21. ....ant is subjected to predetermined corrections and processing in a process unit (not shown), etc., and then sent to the print head 106.
is sent as print data.

The print head 106 includes a plurality of print elements p1, p2, respectively corresponding to one line (column) of pixel data Bll, a21+, . . . ant. . . . pn are arranged in the vertical direction corresponding to the vertical direction of the television image, and scanned in the horizontal direction corresponding to the horizontal scanning direction of the television image. However, the print head 106
As a result, each print element 1 prints a dot according to the content of the corresponding image data ajl each time the print element 1 scans one line at a time.
A hard copy 110 of the television image 100 is formed on the paper 108 (FIG. 5D).

(Problems to be Solved by the Invention) As described above, conventional video printers can only produce hard copies that are similar to television images, which is sufficient for everyday use.

However, as the image quality of video printers has improved, attempts have been made to develop and utilize printed images in various ways, such as use in design cards such as telephone cards.

In that case, if an image is to be printed by a conventional video printer, the photographic paper 120 would be attached to the card substrate 122 with the printing section 120a facing up as shown in FIG. Not only is it not good, but if water or sweat gets on it, the ink PQ will smear and the image will be blurry, which is bad.

Therefore, as shown in FIG. 7, a transparent film 124 is placed on the surface.
A possible solution would be to cover the card with a layer of paper, but this would be cumbersome to manufacture and would make the card thicker, so it is not very desirable.

An effective solution to this problem is to form a horizontally inverted print image on a transparent photographic paper 130, as shown in FIG. is to paste. In this way, from the side facing the front of the card (from the direction of the arrow), a normal image (not reversed left and right), that is, a printed image similar to a television image, can be seen through the transparent photographic paper 1'30. A design card with such a structure has a good surface texture, good image preservation, and is easy to produce.

The present invention has been made in view of such problems, and an object of the present invention is to provide a video printer that can obtain a horizontally reversed print image.

(Means for Solving the Problems) In order to achieve the above object, the present invention reads out pixel data line by line in the horizontal or vertical direction from an image memory that stores pixel data for one image, and scans the pixel data in the printing scanning direction. A video printer configured to perform printing on one printing line in a direction perpendicular to the image memory is provided with means for reversing the order of lines of pixel data read out from an image memory.

(Operation) The direction (horizontal or vertical) of the line of pixel data read out from the image memory corresponds to the horizontal or vertical direction of the television image.

When the print scanning direction corresponds to the horizontal direction of the television image and the print lines correspond to the vertical direction, the direction of the line of pixel data read from the image memory is the vertical direction.

In such a scanning method, when the order of lines of pixel data is reversed, the arrangement order of print lines is reversed, and as a result, a horizontally reversed print image is created.

(Embodiment) Hereinafter, an embodiment in which the present invention is applied to a yH degree gradation control type thermal video printer will be described with reference to FIGS. 1 to 4.

First, I will explain the density gradation control type thermal method. This method applies a constant voltage to each heating resistor element (print element) of the thermal head and controls the energization time to control the gradation of the heat generated energy. The amount of transferred ink and the resulting gradation are applied to each image at a time.

FIG. 4 shows an energization time-density characteristic curve used in the z-scale gradation method. When the heating resistor element is energized for a energizing time tl corresponding to the unit energizing time Δt, a density of gradation level d1 is obtained, and when the heating resistor element is energized for a energizing time t2 corresponding to twice the unit energizing time Δt, the gradation level is obtained. A C degree of d2 can be obtained. In this example, a maximum gradation level dG4 near the saturation density can be obtained by energizing for a energizing time tlli4 corresponding to 64 times the unit energizing time Δt.

FIG. 1 shows the overall configuration of a density gradation control type thermal video printer according to an embodiment of the present invention.

The print head 40 has a plurality of (for example, 1024)
A heat generating resistor 42 is formed by arranging heat generating resistive elements R1 to R1024 in a line in a direction perpendicular to the scanning direction, and a shift register 44 and a latch circuit 46 each having a bit capacity of the same number (1024) as the heat generating resistive elements. It is provided.

Therefore, for one printing line, 1024-pit serial gradation data [Ck pH#CkP10241] is continuously outputted as printing data 64 times (k: 1 to 64) at a constant period by the data comparison circuit 18, which will be described later. The signal is supplied to the shift register 44. Here, the j-th bit CkPJl has information as to whether or not the j-th heating resistance element Rj should be energized for a unit energization time Δt. In other words, if it is "1", it instructs energization, and '0
”, instructs to de-energize.

After each gradation data is loaded into the shift register 44, each bit CkpH to CkP1 is changed at a predetermined timing.
0241 is sent as an electric pulse to the heating resistor 42 via the latch circuit 46, and the heating resistive elements R1 to R1024 are selectively energized for a unit energizing time Δt according to the information content of the corresponding bit. By repeating this operation 64 times (k=1 to 64) for the gradation data, the maximum unit current-carrying time Δt
The current is applied for a cumulative time length corresponding to 64 times as long as 64, and one of 64 density gradation levels is given to each pixel in one print line.

The selector circuit 34 is for avoiding excessive power consumption or heat generation when all the heating resistance elements are energized at the same time.
512) and group B (R513 to R1024), and each group is made energized in a time-divided manner.

Now, the frame memory 10 contains the 1 to be printed.
The digital color video signal that makes up the television image frame is pixel data a11. a12.・・・・・・
...is stored as an■. This frame memory 10
Each row corresponds to a horizontal scanning line of a television image, and contains pixel data a11. a12. . . . an- is written in an order corresponding to raster scanning.

Pixel data is read out from the frame memory 10 line by line [AI] (1=1-+s) starting from the first column, and is once latched into the line buffer 12. After that, pixel data [a ll,
a21. .
J:l-1024). Each concentration data FSj
i has a value (gradation level) corresponding to the density of the corresponding pixel within the range of (0) (minimum density) to (64>(maximum density)).

The density data for one line [FS 10241] outputted from the color process circuit 14 is once latched in the line buffer 16 and then sent to the data comparison circuit 18, where it is latched in the line buffer 16 and sent to the data comparison circuit 18, where it is latched in the line buffer 16 and sent to the data comparison circuit 18, where it is divided into 64 (times) gradations. Data [C
It is converted into kP■~CkP10241ko (k=1~G4).

The gradation counter 28 provides a total of up to 64 count pulses QP to the data comparison circuit 18 at time intervals corresponding to the unit energization time Δt in each energization interval. Then, each time the gradation counter 28 generates a count pulse QP, the DMA controller 26 accesses the line buffer 16 in synchronization with it and stores the density data [FSII to F
S 10241 ].

The data comparison circuit 18 calculates the cumulative value N of the count pulses QP.
The gradation level DN corresponding to the gradation level DN is compared with each density data FSJI as a comparison reference value, and when the latter is equal to or larger than the former, a gradation bit Ck Pjl of "1" is generated.

- For example, concentration data FSI1. FS21. The values of FS31 (gradation level) are <10> and <2>, respectively.

(1), the comparison reference value is (1) in the first comparison in response to the first count pulse QP, so the first gradation bit C+ PH, CI output at this time
P2+ and CI P31 are “1”, “1”, and ’1” respectively.
becomes. In the second comparison in response to the second count pulse QP, the comparison reference value is (2), so the second gradation bits C2P, C2P21, .
C2P31 is “1” ial” and ‘0” respectively.
becomes. Then, when the third count pulse QP is applied, since the comparison reference value is (3), the third gradation bits C3pH, C3P21 . C3P31 becomes "1", '0', and '0', respectively.

In this way, the data F S j 1 (jm1-1024) is compared once each during one energization interval with the comparison reference values (1 to 64) that are incremented by 1, and the 64 pieces (times) of gradation data [CI
pH, CI P21. CI P31...CIP
IO241 ~ [CG4P11. CG4P2
1. CG4P3 卜...C64PI0241
] are sequentially output from the data comparator circuit 18 to the shift register 44 of the print head 40 at regular intervals. and,
By the operation within the print head 40 as described above, printing on one printing line in a direction perpendicular to the printing scanning direction is performed in a density gradation controlled manner.

Note that the DMA controller 24 directly controls the read and write operations of the line buffer 12, and the latch strobe generation circuit 30 sends a latch timing signal LT to the latch circuit 46 in response to the count pulse of the gradation counter 28, and outputs the latch timing signal LT to the selector. A voltage application timing signal VT is applied to the circuit 44.

Now, according to this embodiment, the CPU 20 and the DMA controller 22 operate in response to the operation of the horizontal inversion button 30, so that the line [Al1°[A2co, . . .] of pixel data read out from the frame memory 10 is [A■
] is reversed, and this makes it possible to obtain a print image that is a left-right reversed version of the television image.

This feature of this embodiment will be explained below with reference to FIGS. 2 and 3.

In FIG. 2, control signals C1 and C2 from the CPU 20
DMA controller 22A generates a row address signal, and DMA controller 22B generates a column address signal, respectively. At the time of reading, the control signal C3 is "0" in the normal mode and "1" in the horizontal inversion mode when the horizontal inversion button 30 is pressed.

The controller 22B has an up/down counter, and when the control signal C3 is "0" at the time of sequential output, AI, A2 .
...Generates a column address signal that increments with Am. In this case, pixel data is read line by line starting from the first column AI to the mth column A,
As a result, the print head 40 has... [Ck Pl
il-Ck P10241-1, [CkP11~Ck
P10241], [:Ck P11+I-C
By supplying the gradation data in the order of 6PI0241+1]..., a print image similar to a television image is created.

However, when the left/right inversion button 30 is pressed and the control signal C3 becomes "1" during reading, the controller 22B
s+...A2. Generate a column address signal that decrements with AI. In this case, pixel data is read line by line starting from the m-th column A to the first column AI.

As a result, as shown in Figure 3, it is printed.

In code 40...[Ck PII+1-Ck PI0
241+l Ko.

[CkPt+~Ck P10241], [Ck
By supplying the gradation data in the order of PH-1 to Ck P102411], a print image 50 is created by horizontally inverting the television image. If a transparent film is selected as the paper 52 for this printed image, it can be used for a design card as shown in FIG.

Note that pixel data (ajl, aj21...a jm) is read out line by line from the first line of the frame memory, and on the other hand, in the print head, a plurality of heating resistors each corresponding to one line of pixel data are read out. Element R1, R
The present invention can also be applied to a video printer in which 2,...R■ are arranged in a direction corresponding to the horizontal direction of the television image and scanned in a direction corresponding to the vertical direction of the television image. be.

(Effects of the Invention) As described above, the present invention is capable of obtaining a print image by reversing the order of the lines of pixel data read from the image memory to obtain a print image that is a left-right reversed TV image. It has the effect of greatly expanding the degree of use and scope of application.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of a density gradation control type thermal video printer according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a specific example of the DMA controller 22 shown in FIG. 1. , Fig. 3 is a schematic plan view for explaining the effect of the screen inversion mode, Fig. 4 is a diagram showing the energization time/density characteristic curve used in the density gradation control method, and Fig. 5 is a diagram showing the conventional 6 and 7 are schematic cross-sectional views of a design card using images printed by a conventional video printer. FIG. 8 is a diagram for schematically explaining signal processing in a video printer. 8 is a schematic cross-sectional view of a designed card according to an effective solution to the problem of the card of FIG. 7; FIG. 10... Frame memory, 14... Color process circuit, 18... Data comparison circuit, 20
...CPU, 22...DMA controller, 28...gradation counter, 30...horizontal inversion button, 40...print head, 42...
- Heat generating resistor, 44...shift register, R1, R2, ~R1024... heat generating resistor element.

Claims (1)

[Claims] Pixel data is read out horizontally or vertically one line at a time from an image memory that stores pixel data for one image, and printing is performed on one printing line in a direction perpendicular to the printing scanning direction. A video printer according to the present invention, further comprising means for reversing the order of lines of the pixel data read from the image memory.