JPS645314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention inputs and stores a wide variety of character and graphic information into an image file at a center, and transmits image information requested from an image display terminal installed in a general home or office through a telephone line. The present invention relates to an image information transmission and image display method in a system that transmits color image information and provides color image information to an image display terminal.

As an image display system, a system using a graphic display device has been put into practical use. However, in this method, pattern transmission is performed only for graphic information, and code transmission is used for character information, so a character generator is built into the display terminal. For this reason, especially in the case of displaying Chinese characters, the scale of the character generator has increased, creating an obstacle to miniaturization and price reduction of terminals. For this reason, it is conceivable to transmit character information in a pattern, but in the conventional transmission method, as shown in Fig. 1, identification codes D ₁ and D ₂ are added before the address A, characters, and graphic information DA. The drawback was that the amount of data was large and the transmission time was long. Furthermore, even though the display contents of the previous screen were only partially different, data for one screen was being transmitted, which also increased the transmission time.

The purpose of the present invention is to eliminate such drawbacks, and the purpose is to compose control signals, color information, and image information transmitted from the center to the terminal into packets, and to transmit the image information to the pixels that display the image information on the terminal. The screen is transmitted in a pattern corresponding to
The feature is that only the image information that differs between the next screen to be displayed and the already displayed screen is transmitted from the center to the terminal, and the already displayed screen is rewritten with the different image information and a new screen is displayed. This is achieved by an image display method.

The present invention will be described in detail below based on examples. FIG. 2 shows an example of a packet transmission format according to the present invention, and FIG. 3 shows a display screen.

Image information is transmitted from the center to the terminal in the following order: first the screen control packet shown in Figure a, then the color information packet shown in Figure b, followed by the dot pattern packet shown in Figure c, or the character pattern packet shown in Figure d.

PC ₁ , PC ₂ , PC ₃ , and PC ₄ of each packet represent the packet identification code, D specifies the display mode such as scrolling, screen erasure, and rewriting, and BC ₁ and BC ₂ specify the screen back color. F specifies the flashing color of the display pattern. The color information packet specifies the color for one line shown in Fig. 3 in blocks of 12 pixels vertically x 8 pixels horizontally, where Y ₁ indicates the line number, C ₀ , C ₁ , C ₂ ,
..., C _n is color information that specifies the color of each block in the horizontal direction.

The dot pattern packet is 1 in FIG.
It displays lines, where Y ₀ specifies the line number, and P ₀ , P ₁ , P ₂ , . . . P _o is each image information of the Y ₀ line. For character pattern packets,
Y ₁ is the line number, X ₁ is the address corresponding to the horizontal color specification block, P ₀ , P ₁ , P ₂ ,..., P _e is
This is the dot information of the characters to be displayed in the Y ₁ and X ₁ blocks. Such a packet is input to the image display terminal shown in FIG.

Each packet 1 is sent to the interface circuit 2.
The packet is received by PCi (i=1, 2, 3, 4), and the display address (Y ₀ , Y ₁ ,
X ₁ ) and data, the address 5 is converted by the address setting circuit 3 into an address 77 corresponding to the memory 4, and then instructed to the memory 4. On the other hand, dot information P (P ₀ , P ₁ , P ₂ ,...P _o or P ₀ ,
P ₁ , P _{2 .} . . , P _e ) are sent to the memory 4 via 6 and stored at address 7 .

FIG. 5 shows a detailed embodiment of the configuration of the terminal shown in FIG. 4. A packet 1 from the center is received by an interface circuit 2, and an identification circuit 8 discriminates and divides the type, screen control information, display address, and color designation pattern data of each packet. The rewriting or screen erasing information contained in part D of the screen control packet is sent to the rewriting or erasing control circuit 82 via line 81. Other screen control information BC ₁ , BC ₂ , F are stored in screen control memory 10 via line 83. Also, color information C ₀ , C ₁ ,
...C _n is similarly output to line 83, but its display address Y ₁ is input to memory address setting circuit 9 via line 84, converted into an address, and output to line 91.
Store C ₀ , C ₁ , ..., C _n in 0. On the other hand, in the case of pattern data, its display dress Y ₀ is line 8
5, the address is converted by the memory address _setting circuit 11 _, and the address of the pattern memory ₁₂ is specified via the line 110. is stored in the pattern memory 12 at the address of .

In this way, screen control information and pattern information are
Since the signals are stored separately in the respective memories 10 and 12, when outputting as video information, the video signal is synthesized by the video synthesis circuit 13 and outputted as a video signal on the line 131. When displaying in this manner, there may be similar screens with almost no difference in image information between the immediately previous screen (referred to as the previous screen) and the next screen to be displayed (referred to as the next screen). An example of this is shown in FIG. On the previous screen in figure a and the next screen in figure b, the information 14 and 15 on the previous screen is transferred to 1 on the next screen as shown in figure c.
It only changes to 6 and 17. In this case b
Since it would be very wasteful to newly transmit the screen information shown in the figure, in the present invention, only changed information 16 and 17 (referred to as difference information) as shown in figure c is transmitted and rewritten.

The above is achieved in the following manner in FIG. The control signal for the rewrite mode is sent to the control circuit 8.
When the control signal is logic “1”,
It is in rewrite mode.

In this rewrite mode, address setting circuit 9 screen control information, memory 10, address setting 1
1. The pattern memory 12 operates once and keeps the previous screen information as it is in the memory state.

Next, the difference information is newly addressed through the path of line 85 → address setting circuit 11 → line 110, and only the difference information is written into the pattern memory 12 through line 86. Other previous screen information is held, and the contents of the pattern memory 12 are created as next screen information.

As described above, according to the present invention, control information,
Images, information, and color information are transmitted in packets, and the image information is transmitted as patterns corresponding to pixels, so there is no need for identification codes, reducing the amount of data, and it is not necessary to provide a character generator on the terminal. disappears.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional image information transmission format, FIG. 2 is a diagram showing a transmission format according to the present invention, FIG. 3 is a diagram showing an example of a screen display, and FIG.
5 is a diagram showing an outline of the configuration of a terminal, FIG. 5 is a diagram showing a specific example of the terminal in FIG. 4, and FIG. 6 is a diagram for explaining differential information transmission. In the figure, PC ₁ , PC ₂ , PC ₃ , and PC ₄ are packet identification codes, Y ₁ is a row number, Y ₀ is a line number, X ₁ is a column number, C ₀ to C _n are color information, and P ₀ to P _o and P ₀ to _{P e} are pixel information.

Claims (1)

[Claims] 1. In order to transmit only screens that are different from the screens already displayed from the center to the terminal, control information,
Each of the color information and image information is made into a packet, and the packet of color information and image information further includes an address on the screen, and the terminal is provided with an address setting circuit and a memory corresponding to the screen.
In an image display method that displays a new screen by changing an already displayed screen by writing the color information or image information to an address location included in the packet in the memory according to the content of the control information, The information packet consists of color specification information for each block consisting of n pixels in the vertical direction and m pixels in the horizontal direction, and line number information for each block.In the case of a dot pattern, the image information packet includes the line number and information in pixel units. Accordingly, in the case of a character pattern, an image display method is characterized in that the character pattern is composed of the row and column number of each block and the dot information within each block.