JP3036112B2 - Multi-screen display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-screen display device which combines and displays a plurality of reduced screens on one screen by using an image memory having a register.

[0002]

2. Description of the Related Art Conventionally, this type of N ² screen display device (N is an integer of 2 or more) includes a plurality of image memories divided into N ² blocks, and writes a reduced image on each image memory. , by reading the continuous as a single screen in the form of connecting each image memory at the time of reading, and is configured to allow N ² screen display.

FIG. 2 shows a configuration of a conventional four-screen display device when N = 2. FIG. 2A shows input of image data to a plurality of divided image memories, and FIG. 2B shows a state in which image data stored in the divided image memories is read. In FIG. 2A, the image memory 2
Image memories 1, 22, 23, and 24 are divided into four blocks, and are connected to input signals A, B, C, and D, respectively. In FIG. 2B, reference numeral 25 denotes a memory read state, in which data written in the memory is continuously read in a form of connecting the memories 21 to 24.

Next, the operation and operation will be described. In FIG. 2A, since N = 2, the input signals A, B, C and D of the image data are written into the image memories 21, 22, 23 and 24 at a sampling rate of 1/2. The image data thus written is stored in the image memory 21,
By successively reading data from 22, 23, and 24, four screens can be displayed side by side on one screen as in the memory read state 25 shown in FIG. 2B.

[0005]

However, in the conventional multi-screen display device, when the number of screen divisions is N ² , N ²
, The capacity of one image memory is smaller than when using N image memories, and there is a problem that a large-capacity memory with a low unit cost of memory bits cannot be used. .

An object of the present invention is to solve such a conventional problem, and to provide a multi-screen display device at a low price by making it possible to use a large-capacity memory with a low unit cost. Is what you do.

[0007]

In order to achieve the above object, the present invention provides first to fourth registers for holding asynchronous input signals, and writing to the first and second registers .
So that the first and second input signals do not overlap.
And alternately read from the first and second registers.
A first image memory for storing the output signal;
And third and fourth input signals written to the fourth register
Are read alternately so that they do not overlap, and the third and
A second memory for storing signals alternately read from the four registers
And an image synthesizing means for synchronizingly reading out the signals stored in the first and second image memories and generating a synthesized image.

[0008]

Therefore, according to the present invention, the input signals are respectively sent to the N registers having a register length longer than the length of data accessible by one address of the image memory provided on the input side of the image memory. writing at the sampling rate, reading so as not to overlap each other between the registers in N times of the writing speed, by writing the read data to the image memory, can reduce the memory block from the ^two N to N and thus it is possible to increase the capacity per picture memory, therefore it is possible to use a large-capacity memory, N ² screen display device can be realized at low cost.

[0009]

FIG. 1 shows an embodiment of a four-screen display device when N = 2 in the present invention. FIG. 1A shows an input of the image memory to the image memory, and FIG. 1B shows a state in which the image data is read. In FIG. 1A, 1 and 2, 4 and 5
Each is a register for writing image data at a sampling rate of 1/2 and reading it at twice the sampling rate. Each of 3 and 6 is an image memory. The registers 1, 2, 4 and 5 are connected to the input sides of the image memories 3 and 6, respectively. Reference numeral 7 denotes an image memory reading state, in which data is continuously read out by connecting the image memories 3 and 6 so that the input signals A, B, C, and D are displayed on one screen.

Next, the operation will be described. Input signal A is written to register 1 at a sampling rate of 1/2,
As in another input signal B, the data is written into the register 2 at a sampling rate of 1/2. On the other hand, register 1
And 2 are alternately read and written to the image memory 3 so as not to overlap. Similarly, input signals C and D are also supplied to the image memory 6 via the registers 4 and 5, respectively.
Write to After that, data is continuously read out in a form of connecting the image memories 3 and 6, and four screens are displayed on one screen in the image memory read state 7 as shown in FIG. 1B. As described above, according to the above-described embodiment, the input signals A, B and C, D of two systems are respectively written into one image memory 3 and 6, respectively, so that the capacity of the image memories 3 and 6 becomes one system. It has the advantage that it has a larger capacity than the case of writing an input signal, can use an image memory with a low bit unit cost, and can realize a four-screen display device at a low price.

In the above embodiment, the case where N = 2 has been described. However, the same effect can be obtained with an N ² screen display device where N = 3 or more.

[0012]

According to the present invention, as is apparent from the above embodiment, since two input signals are written into one image signal via a register, the image memory has a large capacity and a bit-wise inexpensive image memory can be provided. Can be used . Also input
By providing a register between the signal and the image memory,
Synchronize input signals that are synchronous and record them in the image memory.
It has the effect of being able to remember .

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams illustrating the operation of a four-screen display device according to an embodiment of the present invention. FIG. 1A is a diagram illustrating an input state of image data. FIG.

FIGS. 2A and 2B are explanatory diagrams of the operation of a conventional four-screen display device. FIG. 2A is an image data input state diagram. FIG.

[Explanation of symbols]

 1 register 2 register 3 image memory 4 register 5 register 6 image memory 7 image memory reading state

Claims (1)

(57) [Claims] A first register for holding an input signal which is asynchronous; and a first register and a fourth register for writing to the first and second registers .
The first and second input signals are interchanged so that they do not overlap.
Read from each other and alternately read from the first and second registers.
A first image memory for storing the extracted signals, and third and fourth input signals written in the third and fourth registers.
So as not to overlap the item, read alternately, the third and
A second image memory for storing signals alternately read from the fourth register, and image synthesizing means for synchronizingly reading the signals stored in the first and second image memories and generating a synthesized image; A multi-screen display device comprising: