JPH0230514B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a display device, and in particular,
The present invention relates to a CRT display device having a function of superimposing display screens, in which lower screen information can be suppressed from being displayed as necessary.

[Prior art and its problems]

Raster scan type CRT display device is
Corresponding to one pixel or each coordinate position (for example, in the case of character display), a predetermined number of pixels or each coordinate position are arranged in vertical and horizontal positions on the screen to form one screen. In this case, there is usually a 1:1 correspondence between the refresh memory and the display screen.

By the way, in the case of a color display device, one pixel or each coordinate position is red (hereinafter referred to as R),
The data corresponds to the three primary colors green (hereinafter referred to as G), blue (hereinafter referred to as B), and the four bits of flicker (F), and the combination of the three primary colors R, G, and B produces white, red,
Expresses green, blue, cyan, magenta, yellow, and black.

Here, black is a state in which the phosphor of the CRT is not emitting light, and the background color of the CRT is visible. On the other hand, fritz information is information indicating the presence or absence of fritz, and in the case of fritz "present",
The dots on the screen are periodically switched between display colors designated by R, G, and B and black. Note that this flicker serves to alert those viewing the CRT display.

By the way, recent CRT display devices are
One way to improve functionality is by overlapping multiple display screens and displaying them on a single CRT screen, or by using part of the overlapping upper display screen as a window to peek into the lower display screen. Some proposals have been made to provide a so-called window function.

In the case of the former superimposition, the lower display screen cannot be seen where there is a picture on the superimposed upper display screen, and the lower display screen is visible only where there is no picture (the upper screen is transparent). become. On the other hand, in the case of the latter window, the information on the bottom screen looks like a piece of black paper with the window frame cut out.
(The window frame will be the opaque part).

Considering this in terms of a CRT display device, 2
To superimpose two display screens, prepare two refresh memories that support one screen, place one on the top and the other on the bottom, and use the display information (or display data, hereinafter referred to as , display information), the lower screen information is invalidated and displayed, and when the upper screen information has no display information (black display), the lower screen information is displayed. It will be displayed as valid. Also, when considering windows, if there is no display information (black display) on the upper screen, it is determined whether to extract the display information on the lower screen and whether it is inside the window frame or not. Furthermore, in addition to such processing, the capacity of the refresh memory must be increased in order to specify the range of the window frame.

[Purpose of the invention]

The present invention has been made in view of the drawbacks of the prior art, and it eliminates these drawbacks and also allows for simple processing of overlapping screens without increasing the capacity of the refresh memory. The purpose of the present invention is to provide a display device capable of processing window frames.

[Key points of the invention]

The display device of the present invention is characterized in that the screen information stored in the first refresh memory is used as the upper screen information, and the screen information stored in the second refresh memory is used as the screen information stored in the second refresh memory. When displaying these two screens in a superimposed manner with the screen as the lower screen, this flicker information is predetermined by referring to the flicker information corresponding to the position where there is no display information in the screen information of the first refresh memory. When the second refresh memory is in one of the states, the display information at the corresponding position in the screen information of the second refresh memory is prohibited from being displayed.

In this way, by using flicker information at a position where there is no display information, that is, flicker information for black display, and whether or not there is flicker, two screens can be easily adjusted without increasing the capacity of the refresh memory. This makes it possible to overlap and process window frames.

Here, to explain the principle of the present invention, flicker designation for a dot for which a display color has been designated is meaningful by making the display color blink. In this case, a predetermined display color and black are alternately displayed, resulting in a point reduction state. However, in the case of so-called black display without designation of a display color, designation of flicker results in switching between black and black, and the flicker itself has no meaning and no blinking state occurs.

On the other hand, when the screen information of two display screens is overlapped, the display information of the lower screen is displayed in areas where there is no display information in the screen information of the upper screen, that is, in the black display area without pictures. hand,
The two display screens will overlap. However, when displaying in a window, the black display area inside the window frame displays the lower display information, and the black display area outside the window frame displays the lower display information. All you have to do is not display the information.

Therefore, for the display information in the upper screen information, for the black display area where there is no display information, flicker information, which is meaningless information in black display, is used to display the lower display information. If this information is used separately for information that means that the display information on the lower side is not displayed, and information that means that the display information on the lower side is not displayed, the above separation can be made. That is, by effectively utilizing this flicker information, the upper screen can be made transparent or opaque.

As a result, it is possible to overlap two pieces of screen information or frame them on the lower screen without increasing the refresh memory.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a refresh memory portion of an embodiment of a display device to which the present invention is applied.

In the figure, 1 is the first refresh memory,
2 is a second refresh memory.

These first and second refresh memories 1 and 2
are accessed by a dot address signal sent to the dot address signal line 3 from a display control unit (not shown), and output 3-bit display information of R, G, and B to an R output signal under predetermined conditions. line 5, G output signal line 6, and B output signal line 7
Output to.

Here, the first and second refresh memories 12
have the same configuration, and the first refresh memory 1 includes a memory 11a that stores screen information for one screen and a flicker/priority determination section 12.
a and a display information output 13a. Also,
The second refresh memory 2 includes a memory 11b that stores screen information for one screen, a flicker/priority determination section 12b, and a display information output section 13b.

Each of the memories 11a and 11b stores 4-bit display data of R, G, and B display information and F flicker information corresponding to each dot position on the screen as screen information. These memories 11a, 11b
is addressed by the dot address signal sent to the dot address signal line 3, and displays 4-bit display data of R, G, B display information and F flicker information at that position to the display information 16a, 16.
b, read out as flicker information 17a, 17b,
These are sent to the flicker/priority determination sections 12a and 12b, and at the same time, 3-bit display information 16a and 16b of R, G, and B are sent to the display information output section 13, respectively.
a, 13b.

Here, the flicker/priority determination units 12a and 12b
In addition to the 4-bit information of display information 16a, 16b and flicker information 17a, 17b, respectively,
A flicker timing signal is received from a flicker timing signal line 4. Then, the flicker/priority determining unit 12a or 12b respectively determines whether at least one bit of the three bits of R, G, and B display information 16a, 16b is "1". Then, when any bit is "1", the value of flicker information 17 (value of F) is referred to, and if this is "1" (flicker present), it corresponds to the flicker timing signal. A flicker signal 18a or 18b is generated to inhibit the output of the priority output signal 15a15b, respectively. Note that when at least one bit is "1", it means that a display color is specified.

Now, referring to the value of flicker information 17 (value of F), if it is "1" (flicker present) and no flicker timing signal is received, or if the value of flicker information 17 is "0" ( (no flicker), the flicker/priority determination unit 12a,
12b is the flicker signal 18a or 1, respectively.
8b is prohibited and the priority output signal 15a or 1
Outputs 5b. Further, when the value of flicker information 17 (value of F) is "1" (flicker present) and a flicker timing signal is received, flicker signal 18a or 18b is output and priority output is made. Prohibits output of signal 15a or 15b.

On the other hand, 3-bit display information 16 of R, G, and B
At least one of bits a and 16b
Determine whether the two bits are “1” or not,
When either bit is "0", the flicker signal 18a or 18b is not generated regardless of the presence or absence of the flicker timing signal. At this time, referring to the value of flicker information 17 (value of F), if this is "1", priority output signals 15a, 15b
is output, and when this is "0", the output of priority output signals 15a and 15b is prohibited.

Here, the generated flicker signal 18a or 18
b is sent to the display information output section 13a, 13b of each refresh memory, while the priority output signal 15a is sent to the display information output section 13b of the second refresh memory 2.

Here, the priority output signal is a signal that prohibits the output of lower refresh memory display information (corresponding to the lower screen);
The second refresh memory 2 is subordinate to the refresh memory 1, and this priority output signal 1
5a prohibits output of the display information. Note that the first refresh memory 1 stores screen information that becomes the upper screen when superimposed, and is superior to the second refresh memory 2. Therefore, if there is a lower refresh memory than this, the priority output signal 15b of the second refresh memory 2 is sent to the lower refresh memory, and the output of the display information of that refresh memory is prohibited. do.

Further, the flicker signal is for displaying black in accordance with the flicker timing, and inhibits the output signal of the refresh memory.

As a result of the above, when the flicker signal 18a is not received, the display information output 13a of the first refresh memory 1 that receives the 3-bit display information 16a of R, G, and B is The 3-bit display information 16a is output to the R output signal 5, the G output signal line 6, and the B output signal line 7. and,
A priority output signal 15a is sent to the second refresh memory 2. In addition, the flicker signal 18a
When received, the output of the display information output section 13a is prohibited.

On the other hand, the display information output section 13b of the second refresh memory 2 which receives the priority output signal 15a of the first refresh memory 1 via the priority output input line 14b outputs the R, G,
Output of the B 3-bit display information 16b is prohibited. Furthermore, when the flicker signal 18b is received, the output of the display information output 13b is prohibited.

By the way, if a refresh memory exists as a memory higher than the first refresh memory 1 (not shown), a similar priority output signal is sent to the display information output section 13 of the first refresh memory.
When a is received via the priority output input line 14a, the three of R, G, and B sent from the memory 11a are
The bit display information 16a will not be output. Furthermore, if there is a refresh memory (not shown) as a memory lower than the second refresh memory 2, the priority output signal 1
5b is sent to the display information output section, and the output of the display information of the refresh memory is prohibited.

Next, the overall operation in the case of overlapping processing including window processing will be explained. When the first and second refresh memories are addressed by the dot address signal sent to the dot address signal line 3, Display information 1 from each memory 11a, 11b
6a, 16b are output, R of display information 16a,
At least one of the 3 bits of G and B is “1”
At this time, the priority signal 15a is output from the display information output section 13a to the second refresh memory 2, and the display information 16 of the second refresh memory 2 is
The output of b is suppressed. And 3 of R, G, B
The bit display information 16a is displayed on the display information output section 13a.
The signal is output from the R output signal line 5, the G output signal line 6, and the B output signal line 7 for display processing.

As a result, only the display information of the screen information of the first refresh memory 1, that is, only the display information of the upper screen is displayed on the display screen, and at this time, the display information of the lower screen is not displayed. . In this case, it is assumed that the flicker signal 18a is not generated in the first refresh memory 1.

Here, if this flicker signal 18a is occurring, that is, the flicker information 17 that has been read out
When a is "1" and coincides with the flicker timing, a flicker signal 18a is generated in accordance with the flicker timing, and the display information output section 13a receives it, so that the display information output section 1
3a is prohibited, and the display information on the upper screen is not displayed, but the display information on the lower screen is displayed.

That is, at the same time, the output of the priority output signal 15a of the first refresh memory 1 is prohibited and is not output to the second refresh memory 2, so that the display information 16b of the second refresh memory 2 is lowered. As display information on the side screen, an R output signal line 5, a G output signal line 6,
It is output to the B output signal line 7. As a result, only the display information on the lower screen is displayed on the display screen.

Note that at this time, the second refresh memory 2
It is assumed that the flicker signal 18b is not generated.

On the other hand, the display information corresponding to the upper screen is read out in this way, and the display information 16a, 16b is output from each memory 11a, 11b.
When all three R, G, and B bits of a are "0" and the flicker information is "0", the display information of the lower screen is displayed on the display screen.
That is, R, G,
The outputs of the 3-bit B display information 16a are all "0", and furthermore, the priority output signal 15a is not output. Therefore, regardless of the flicker timing, the display information 16b read from the second refresh memory 2 is output from the display information output section 13b to the R output signal line 5, the G output signal line 6, and the B output signal line 7. That will happen. As a result, the display information on the lower screen will be displayed on the display screen.

In this case as well, it is assumed that the flicker signal 18b is not generated in the second refresh memory 2.

Here, display information 16a, 16b is output from each memory 11a, 11b, and when all three bits of R, G, and B of display information 16a are "0" and the flicker information is "1", the lower screen The displayed information is not displayed on the display screen, and the screen is simply displayed in black. That is, R,
The outputs of the 3-bit G and B display information 16a are all "0", and the priority output signal 15a is output regardless of the flicker timing. Therefore, the display information 16b read from the second refresh memory 2 is not output from the display information output section 13b to the R output signal line 5, the G output signal line 6, and the B output signal line 7. As a result, only the display information on the upper screen is displayed on the display screen. At this time, the display information of the upper screen information is all "0", so the screen is displayed in black.

Therefore, if you set the area where this display information is all "0" and the flicker information is "1" as a window frame state, the screen information of the second refresh memory 2, which is the screen, will be displayed at the bottom of the window display. It will be possible to display it. In other words, the flicker information is “1”
The area where the flicker information is set to "0" becomes the frame, and the area where the flicker information is set to "0" becomes the lower picture display area. Also, at this time, the display information 16 of the second refresh memory 2
If all the data in b is "0", the display on the lower screen will also be black, and the screen will be displayed in black.

On the other hand, in an area where at least one bit of display information on the upper screen is "1" and all display information is "0", if the flicker information is "0", the area is This is the display area for the lower picture. As a result, the upper and lower two screens can be displayed overlappingly.

By setting the black flicker information to a predetermined value in this manner, it becomes possible to freely set overlay and window processing.

In addition, when the processing of the flicker/priority determination unit 12a and the screen display are compared and shown as a table, the second
As shown in the diagram.

Here, the flicker information stored in the memory 11b of the second refresh memory 2 may be determined depending on the refresh memory installed below it, and the flicker information stored in the memory 11b of the second refresh memory 2 may be determined depending on the refresh memory installed below it. In such cases, this may be set to "1". Furthermore, the second refresh memory 2 does not need to store such flicker information.

As described above, when simply overlapping the upper screen and the lower screen, each bit of the display information in the first refresh memory 1 (upper screen) is all "0", and the corresponding flicker information is set to "0". If the upper screen is set to "0", it corresponds to the screen information frame of the first refresh memory 1 when the upper screen is used as a window. All that is required is to set all the bits of display information to "0" at the necessary locations and to set the flicker information to "1".

Furthermore, as in the embodiment, when at least one of the bits of the display information is "1",
By setting the flicker information to “1”,
The upper screen and the lower screen can also be displayed alternately.

As explained above, in the embodiment, when the flicker information is "1", it is assumed that there is flicker,
Although it is assumed that there is no flicker when the value is "0", it may be set to "1" or "0" instead.

Further, the same applies to each bit of display information, ``1'' and ``0'', and the flicker timing in the table of FIG. 2 is also the same.

In addition, in this invention, flicker information only needs to be provided on the upper screen, and this flicker information does not need to be stored on the memory in correspondence with the display information. For example, in the case of a window,
The information may be stored in the form of flickering range information.

Furthermore, the display information output section may be a simple gate circuit, or may be configured integrally with the flicker/priority determination section. In addition, the first refresh memory 1
The flicker/priority determining unit of the present invention sends out a priority output signal as a signal for prohibiting the display of display information at a corresponding position in the screen information of the second refresh memory. Not limited to things.

Furthermore, these may be processed and realized by a program.

In the embodiment, an example is given in which the refresh memory stores screen information corresponding to display information corresponding to dots, but it goes without saying that this may also be display information corresponding to coordinates. Also,
Although a color display is given as an example, it goes without saying that a so-called black and white display may also be used.

〔Effect of the invention〕

As can be understood from the above explanation, in the present invention, the screen information stored in the first refresh memory is the upper screen information, and the screen information stored in the second refresh memory is the lower screen information. When these two screens are superimposed and displayed as a side screen, this flicker information is predetermined by referring to the flicker information corresponding to the position where there is no display information in the screen information of the first refresh memory. When in one state, the second
Since the display information at the corresponding position in the screen information of the refresh memory is prohibited from being displayed, overlapping and window processing can be easily realized by simply setting the flicker information to a predetermined value.

As a result, there is no need to determine whether the upper screen information is inside the window frame or outside the window frame (outside the window frame) when there is no display information, and in order to specify the range of the window frame, the capacity of the refresh memory is increased. The effect is that it is not necessary.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the refresh memory portion of an embodiment of a display device to which the present invention is applied, and FIG. 2 is an explanatory diagram comparing the processing of the flicker/priority determining section and the screen display and making a table. It is. 1...First refresh memory, 2...Second
Refresh memory, 3...Dot address signal, 4...Flicker timing signal, 5...R output signal line, 6...G output signal line, 7...B output signal line, 11a, 11b...memory , 12a, 12
b... Fritska/priority determination section, 13a, 13b...
...Display information output section, 14a, 14b...Priority output signal input line, 15a, 15b...Priority output signal,
16a, 16b...display information, 17a, 17b...
...Flicker information, 18a, 18b...Flicker signal.

Claims (1)

[Scope of Claims] 1. First and second refresh memories each having a size corresponding to the screen are provided, and each of the first and second refresh memories stores screen information consisting of a plurality of predetermined pieces of display information. At least, the first refresh memory stores flicker information indicating the presence or absence of flicker corresponding to a corresponding pixel or each coordinate position on the screen, and the screen stored in the first refresh memory In the case where the information is displayed on the upper screen and the screen information stored in the second refresh memory is displayed as the lower screen by overlapping these two screens, the screen of the first refresh memory With reference to the flicker information corresponding to a position where there is no display information in the information, when this flicker information is in one predetermined state, the display of the corresponding position in the screen information of the second refresh memory is performed. A display device characterized by prohibiting display of information. 2. It has three or more refresh memories of a size corresponding to the screen, and among these refresh memories, the two refresh memories before and after the screen in the order in which the screens are stacked are the ones in the upper screen corresponding to the order in which the screens are stacked. The refresh memory that stores the screen information is the first refresh memory, and the refresh memory that stores the screen information of the lower screen is the second refresh memory.
2. The display device according to claim 1, wherein the display device is a refresh memory. 3. Claim 1, wherein the display information is color information corresponding to red, green, and blue, and one predetermined state of the flicker information is information with flicker. Display device as described.