JPH0571098B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an image display device, and particularly to a video display device that has two different CRT screens, such as a stereoscopic image display device.
Or it relates to a video display device that displays the same image.

(Prior Art) FIG. 5 shows an outline of the configuration of a three-dimensional image display device, which is an example of this type of video display device. This device includes a CRT 1 that displays images for the left eye and a CRT 2 that displays images for the right eye. these
The image data given to the CRTs 1 and 2 are stored in image data memories 3 and 4 provided separately, respectively. The image data in each image data memory 3 and 4 is provided to each CRT 1 and 2 via video control circuits 5 and 6.

(Problem to be Solved by the Invention) However, in the case of the conventional example having such a configuration, since the image data for the left eye and the image data for the right eye are stored in separate image data memories, However, there is a problem in that the number of image memories increases, which increases the manufacturing cost of the device.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a video display device in which only one video memory is required instead of the two video memories used in such video display devices. The purpose is

(Means for Solving the Problems) FIG. 1 is a block diagram schematically showing the configuration of a video display device according to the present invention.

That is, the video display device according to the present invention includes two displays 11 and 12 that display images. A pair of video memories 13 corresponding to the display device 11,
14, and another pair of video memories 15 and 16 corresponding to the display 12 are provided. The image data memory 17 stores image data of characters given to the video memories 13 to 16. Further, a specimen memory 18 provided in association with the image data memory 17 stores data for selecting the character stored in the image data memory 17, data for determining the position of the character on the screen, the color of the character, etc. I remember.

The image data memory 17 and the specimen memory 18
are connected to the video memories 13 and 14 via switches SW1 and SW2, and
Video memory 15, 16 via SW1 and SW3
It is connected to the. In addition, video memories 13 and 14
is connected to the display 11 via a switch SW4. Video memories 15 and 16 are switch SWs
It is connected to the display 12 via 5. The switches SW1 to SW5 symbolically represent data transmission control means that determine the timing of writing and reading data into each video memory.

(Function) The function of the video display device will be explained with reference to FIG.

Figure a shows the timing of horizontal scanning lines. As shown in Figure b, the switch SW1 is 1
Connect to the contact in the first half of the horizontal scanning period,
It is connected to the contact point in the latter half. Also,
The switches SW2 and SW3 are switched between contact and contact for each horizontal scan. Switch SW
Contrary to the switches SW2 and SW3, the switches 4 and 5 are switched between a contact point and a contact point for each horizontal scan.

Therefore, in the first half of one horizontal scanning period, the image data outputted from the image data memory 17 and the specimen memory 18 are applied to the video memory 14 via the switches SW1 and SW2, and written into this memory. On the other hand, the image data etc. output from the image data memory 17 and the specimen memory 18 in the second half of the one horizontal scanning period are transferred to the switch SW1.
and is given to the video memory 16 via SW3,
written to this memory.

Also, during the horizontal scanning period when the video memories 14 and 16 are being written, the video data in the video memory 13 is transferred to the display 11 via the switch SW4.
given to. Also, during this period, the video data in the video memory 15 is provided to the display 12 via the switch SW5.

In the next horizontal scanning period, switch SW2
~Switch SW5 switches and video memory 1
3 and 15 are written, and the video data in the video memories 14 and 16 is read out and provided to the displays 11 and 12, respectively.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 3 is a block diagram schematically showing the configuration of a video display device according to an embodiment of the present invention. In this figure, the same parts as in FIG. 1 are designated by the same reference numerals.

The specimen memory 18 is composed of a specimen memory for left eye display and a specimen memory for right eye display.
The object memory 18 contains data D1 that determines the vertical position of the character on the screen, and the video data memory 1.
data D2 for determining which character's image data is to be selected from the plurality of character image data stored in 7; data D3 for specifying the color of the character on the screen; and data D3 for specifying the horizontal direction of the character on the screen. Data D4 determining the position of is output. The timing of these data outputs is determined by the control signal S1 of the data transmission control circuit 20.

The data D1 to D3 are sent to latch circuits 31 to 3.
3 are given separately. Data D4 is
The signals are applied to horizontal position counters 41 and 42, respectively.

The output of the latch circuit 31 is given as one input of the comparison arithmetic circuit 50. A vertical scanning synchronizing pulse V is applied as the other input of the comparison arithmetic circuit 50. The vertical line signal which is the output of this comparison arithmetic circuit 50 is given as one input of the image data memory 17. The output of the latch circuit 32 is given as the other input of the image data memory 17.
The image data read from the image data memory 17 is provided to a parallel-to-serial conversion circuit 60. The output of the parallel-serial conversion circuit 60 is transmitted to the video memory 13.
~16 respectively. Further, the output of the latch circuit 33 is applied to the video memories 13-16. On the other hand, the count output of the horizontal position counter 41 which performs a counting operation in response to the clock pulse CP is given to the video memories 13 and 15, and the count output of another horizontal position counter 42 which similarly performs a counting operation in response to the clock pulse CP. The counter output is given to video memories 14 and 16.

The video data in the video memories 13 and 14 are individually applied to a switching circuit 71, respectively. The output of the switching circuit 71 is given to the coloring circuit 18, and the output of the coloring circuit 81 is given to the CRT 11. On the other hand, the video data in the video memories 15 and 16 is provided to each switching circuit 72 individually. The output of the switching circuit 72 is given to the coloring circuit 82,
The output of the coloring circuit 82 is given to the CRT 12.

Next, the operation of this embodiment will be explained.

The data transmission control circuit 20 supplies the data output control signal S1 shown in FIG. 4B to the specimen memory 18 by receiving the horizontal counter signal H shown in FIG. 4A. Thereby, in the first half of one horizontal scanning period of the specimen memory 18, the data D1 to D4 are output from the left eye specimen memory.

The comparison circuit 50, which is supplied with the data D1 via the latch circuit 31, determines the character displayed on the CRT screen based on the comparison between the number of vertical counter signals V supplied as the other input and the data D1. A vertical line signal that determines the vertical length is given to the image data memory 17.

Furthermore, by providing the data D2 to the image data memory 17 via the latch circuit 32,
Image data of a character to be displayed on the CRT 11 is selected.

The image data of the character selected in this manner is subjected to data arrangement conversion by the parallel-to-serial conversion circuit 60, and then is transferred to the video memories 13 to 11.
6 is given. At this time, as shown in FIGS. 4c to 4f, control signals S2 to S5 are applied from the data transmission control circuit 20 to each of the video memories 13 to 16. As a result, in the first half of the first horizontal scanning period 1H shown in FIG. 2A, the specimen memory 14 to which the control signal S3 is applied is in a write state, and the video memory 16 is in a write-inhibited state. Therefore, the image data output from the video data memory 17 is written into the video memory 14.

In addition, data D output from the specimen memory 18
3 is applied to the video memory 14 in the data writing state via the latch circuit 33. As a result, data regarding the color to be added to the character written in the video memory 14 is written into the video memory 14.

Further, horizontal position counters 41 and 42 are provided with data D4 output from the specimen memory 18.
determines the horizontal position of the image data given to the CRT. The horizontal address data output from the horizontal position counter 42 is stored in the video memory 1.
given to 4.

On the other hand, in the second half of the first horizontal scanning period 1H, as shown in FIG. The video memory 14 becomes write-protected. At this time, the specimen memory 18 stores data D1 to D4 for the right eye.
Output. Therefore, with these data, the character image data, color data, and horizontal/vertical address data to be displayed on the CRT 12 for the right eye selected from the image data memory 13 are transferred to the video memory 16 in the same manner as described above. Given.

Further, as shown in FIGS. 4c and 4e, when the video memory 14 and the video memory 16 are in the writing state, the data transmission control circuit 20 sends the control signal S.
2. Video memory 1 given S4 individually
3 and 15 are in the state of reading the video data written therein.

As shown in FIG. 4a, when the second horizontal scanning line 2H is drawn, the video memory 13 to which the control signal S2 is applied from the data transmission control circuit 20 is in a write state during the first half. Therefore, based on the data D1 to D4 of the left eye object memory output during this period, the same image data for the left eye as described above and the like are written into the video memory 13. In addition, in the latter half of the second horizontal scanning line, as shown in FIG. image data etc. are written.

On the other hand, during the second horizontal scanning period 2H, as shown in FIG. 16 is in the read state. Therefore, the data written in the video memories 14 and 16 during the first scanning period will be read from these memories during the second scanning period. The data read from the video memories 14 and 15 are individually applied to switching circuits 71 and 72, respectively.

These switching circuits 71 and 72 correspond to switches SW4 and SW5 in FIG.
The data transmission control circuit 20 switches the contacts at the timing shown in FIG. 4g.
Therefore, in the first scanning period 1H, the video data in the video memory 13 and the video data in the video memory 15 are respectively read out. Also, the second
In the main scanning period 2H, the video data in the video memory 14 and the video data in the video memory 16 are respectively read out. Thereafter, the video data in the paired video memories are read out alternately in the same manner as described above.

The video data output from switching circuits 71 and 72 are individually applied to coloring circuits 81 and 82, respectively. Coloring circuits 81 and 82 convert color data in video data into RGB signals. and,
The outputs of the coloring circuits 81 and 82 are connected to the CRTs 11 and 1.
2, a predetermined image is displayed on each CRT screen.

In the description of the embodiment, a three-dimensional image display device was used as an example, but the present invention is not limited to this and can be applied to various video display devices that display different images on two CRTs.

Furthermore, since the present invention selects any character from a plurality of characters stored in one image data memory and displays it on two CRTs, the two CRTs may have the same or different characters. Of course, any image can be displayed.

(Effects) As described above, the video display device according to the present invention has the following effects:
The image data in the image data memory is selected separately for the first half and the second half of one horizontal scanning period, and is applied individually to the video memories that are paired in correspondence with the two display devices, and Writing and reading are alternately performed on the paired video memories for each horizontal scan, and the read video data is individually provided to the corresponding display.

Therefore, according to the present invention, a desired image can be displayed on two displays using one image data memory, so unlike the conventional device, it is possible to display a desired image on two displays. The number of image memories is halved compared to the case where image memories were provided in the previous model, and the device can be manufactured at a correspondingly lower cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an outline of the configuration of a video display device according to the present invention, FIG. 2 is an operation timing diagram of the device shown in FIG. 1, and FIG. 3 is a schematic diagram of the configuration of an embodiment of the present invention. 4 is an operational timing diagram of the device shown in FIG. 3, and FIG. 5 is a block diagram showing an outline of the configuration of the conventional device. 11, 12...CRT, 13-16...video memory,
17... Image data memory, 18... Specimen memory.

Claims (1)

[Scope of Claims] 1. Two display devices for displaying images, one pair provided corresponding to each of the display devices,
a video memory that stores video data given to each of the display devices; an image data memory that stores character image data given to each video memory; and data that selects the image data stored in the image data memory. , a specimen memory storing data for determining the position of the character on the screen and the color of the character, and a pair of video memories among the video memories for the first half of one horizontal scanning period; In the second half of the image memory, the data of the image data memory and the object memory are individually supplied to another pair of image memories among the image memories, and the image data of each pair is transmitted for each horizontal scan. A video display device comprising: data transmission control means for controlling each of the memories so as to read video data alternately from the memory and provide the data to the corresponding display device.