JPS5936267B2 - Memory addition method for display devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for expanding a dot memory in a display device having a dot memory corresponding to one screen of the display device.

Conventional display devices are equipped with a display device such as a CRT and a dot memory that stores one screen of the display device, and create a display image by reading out this dot memory in synchronization with the raster scanning of the display device. but,
The readout frequency was fixed depending on the capacity of the dot memory, and the frequency could not be changed, resulting in separate devices for each dot memory capacity.

By adding an additional dot memory to a dot memory having a basic capacity, the present invention makes it possible to extremely easily provide various display devices with increased resolution and different numbers of pixels.

According to the present invention, the present invention includes a display device that displays an image and a dot memory that stores information for one screen corresponding to the display screen of the display device, and the read timing of the dot memory and the raster of the display device. In the method of displaying images by synchronizing scanning, 3× of the dot memory
This is achieved by sequentially adding additional dot memories having a capacity of 4n-1 times (n is a natural number) to the dot memory, and at the same time accelerating the readout timing in response to the expanded capacity of the additional dot memories and the dot memory. be done.

The present invention will be explained in detail below with reference to embodiments shown in the drawings.

FIG. 1 shows a display device of the present invention. In the figure, 1 is an interface section for input from a computer, etc., 2 is a character pattern generator and a vector generator that break down this input data into dots, and 3-1 is a vector generator. A dot memory corresponding to one screen of a display image, 4 a TV signal generator, 5 a display device such as a CRT, 3-2 an additional dot memory, 7-1 a clock source, and 8-1 a switching device.

Input from a computer or the like is given to a character pattern generator and a vector generator 2 via an interface section 1, decomposed into dots, and stored in a dot memory 3.

This dot memory 3-1 is sequentially read out by a clock source 7-1 having a frequency fl, converted into a display image by a TV signal generator 4 driven by the same clock source 7-1, and displayed on a display device 5. Here, if we add a dot memory with a capacity 3 x 4n-" (n is a natural number) times the capacity of the basic dot memory 3-1 as an additional dot memory, and for example, if the capacity of the dot memory 3-1 is set to 256 x 256 dots, As additional memory, additional memory 3- with three times the capacity
By adding 2, a dot memory having a total capacity of 512×512 dots is constructed.

Dot memory is read by giving horizontal and vertical address data, and in order to read a dot memory with four times the capacity as one screen, if the vertical frequency is the same, the horizontal frequency is doubled, The readout frequency for one pixel needs to be quadrupled.

Therefore, the device 8-1 for switching the clock source 7-1 to the frequency F2
This shows that switching is performed by Figure 2 shows the configuration of the additional dot memory added in this way.(a)
This is a case where a 3-times additional dot memory 3-2 is added to the basic dot memory 3-1 to constitute a 4-times dot memory, and (b) similarly adds the additional dot memories 3-2, 3-2 to the basic memory 3-1. This is a case where the capacity is increased by 16 times by adding 3 in sequence.

FIG. 3 shows another embodiment of the present invention, in which the additional dot memory and the switching portion of the clock source are arranged in one unit, such as a printed circuit board.

In the figure, the basic printed board Ptl is equipped with a basic dot memory 3-1, a TV signal generator 4, a clock source 7-1 of frequency F, and a switching device 8-1. The data given to the input IN is written to the dot memory 3-1,
A signal from clock source 7-1 is applied to dot memory 3-1 and TV signal generator 4 via switching device 8-1. As a result, data is read from the dot memory 3-1, converted into a display screen by the TV signal generator 4, and sent to the output 0UT. The printed board Pt2 is a printed board equipped with an additional dot memory 3-2 having three times the capacity and a corresponding clock source 7-2.

By adding this printed board Pt2 to the basic printed board Ptl, the capacity of the dot memory is quadrupled, and at the same time, the control signal of the switching device 8-1 of the basic printed board Ptl is dropped from +E to ground, so the clock frequency is reduced to f.
Switch from l to F2. Therefore, the horizontal frequency is doubled,
The readout frequency for one pixel is four times as high. Therefore, the display device as a whole has four times the resolution. Similarly, 1 is added to the basic printed board Pt, and the printed board Pt2.
Printed board P with double capacity dot memory 3-3
By adding t3, the resolution becomes 16 times higher. FIG. 4 shows the situation of additional dot memory and read timing. In the figure, the clock pulse A is a read pulse for -line when reading the basic dot memory 3-1, and each column of the dot memory 3-1 is read out during the timing of each pulse 1, 2, and 3. Similarly, -line data is read out from the additional dot memories 3-2 and 3-3 at the timing of clock pulses B and C, respectively.

As described above, according to the present invention, it is possible to easily increase or decrease the number of dot memories by adding or deleting unitized additional dot memories, and it is possible to easily realize a series of display devices having different resolutions.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the dot memory addition method according to the present invention, FIG. 2 shows the configuration of the additional dot memory, FIG. 3 shows another embodiment of the invention, and FIG. 4 shows the read timing of the dot memory. 1 is an interface section, 2 is a character pattern generator, 3-1 is a basic dot memory, 3-2 and 3-3 are additional dot memories, 4 is a TV signal generator, 5 is a display device, 7
1, 7-2 and 7-3 are clock sources, and 8-1 and 8-2 are switching devices.

Claims (1)

[Claims] 1 A display device that displays an image has a dot memory that stores information for one screen corresponding to the display screen of the display device, and the readout timing of the dot memory and the raster scanning of the display device are synchronized to display the image. In the display method, additional dot memories having a capacity 3×4^n^-^1 (n is a natural number) times the dot memory are sequentially added to the dot memory, and at the same time, the additional dot memories and the dot memory A memory addition method for a display device characterized by speeding up readout timing in response to expanded capacity.