JPS6389926A - Display unit - Google Patents

Abstract

PURPOSE:To reduce the quantity of data to be transferred and shorten time for transfer by providing a change extent extracting section that executes necessary minimum transfer at the time of reflecting partial change of a square image pattern of a first memory section to a second memory section. CONSTITUTION:At the time of reflecting partials change of a square image pattern held in a bit map memory section 1 as the first memory section to a screen memory section 3 as the second memory section, necessary minimum transfer is executed by a change extent extracting section 8. That is, when change occurred, the position of the part of the bit map memory section 1 is detected, and converted to coordinate value on the memory section 3 according to positional information on the screen memory 3, and an area of changed extent is outputted to an area discriminating section 4. The discriminating section 4 divides the extent of changed extent area value into mutually overlapped small square areas using disposition information in a controlling section 2 and makes decision, and transfers an image pattern corresponding to necessary small square area from the memory section 1 to the memory section 3. Thus, the quantity of the data to be transferred is reduced, and time for transfer can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device for displaying the output of an electronic computer as characters or image patterns on a display screen of, for example, a cathode ray tube.

[Conventional technology]

FIG. 3 is a block diagram showing an example of the configuration of a conventional display device of this type. In this FIG.
2 is a focus map memory section serving as a memory section for the plurality of rectangular image patterns; 2 indicates the position, size, and display priority for superimposed display within the bitmap memory section l regarding the plurality of rectangular image patterns;

A display control unit holds as display control information the following positions on the screen memory unit 3 to which the plurality of rectangular image patterns are to be transferred, 3 is a cathode ray tube (hereinafter referred to as C
(abbreviated as RT)-7 is a screen memory section as a second memory section in which an image pattern corresponding to the display screen dots is stored; 4 is an area discriminating section; The area that needs to be changed in the screen memory unit 3 and the corresponding area in the bitmap memory unit 1 are identified according to the change type, and the image pattern transfer operation for the identified area is performed by the following direct memory access controller. A region determining section 5 plays the role of instructing a section 5 (hereinafter abbreviated as DMAC) to transfer data from the bitmap memory section 1 to the screen memory section 3 according to instructions from the area discriminating section 4. A DMAC 16 performs a predetermined scanning process. This is a video control section that plays a role of generating a video signal corresponding to an image pattern to be displayed read out from the screen memory section 3 according to timing.

FIG. 4 shows, for example, three rectangular image patterns IP+,
This is an explanatory diagram illustrating a state in which IPg and IP3 are held in the bitmap memory section 1, and the upper left of each rectangular image butter □ □ 1-pin IPi (+=1.2.3) Assume that the positions of the corner vertices in the bitmap memory unit 1 are xi and yi, which represent the position of the rectangular image pattern IP in the bitmap memory unit 1. In addition, the X-direction size of the rectangular image pattern Pi (i=1.2.3) is represented by (hi), and the X-direction size is represented by vi, and using these, the rectangular image pattern IPiO
Let the sizes be expressed by hi and vi. Furthermore, the display priority of each rectangular image pattern IPi for overlapping display is set to PRi. When P'Ri<PRj, the rectangular image pattern IPi is displayed below IPj, and as a result, a part of the rectangular image pattern TPi is hidden in IPj.

FIG. 5 is an explanatory diagram illustrating that the rectangular image patterns IP+, IPz, and IP shown in FIG. 4 are displayed in a superimposed manner according to a predetermined display priority. Now, these image patterns are PR+
If the display priority is <P Rz <P R3, the above rectangular image pattern I
P, , IP2 and IPff are transferred to predetermined positions in the screen memory section 3 in descending order of display priority, and the state within the screen memory section 3 becomes as shown in FIG. Then, the position in the screen memory section 3 of the top left corner vertex of each rectangular image pattern IPi is
, βi, and this is shown as the position of the rectangular image pattern IPi in the screen memory section 3.

FIG. 6 specifically shows the control information held by the display control section 2 in order to generate the state of the screen memory section 3 shown in FIG. 5 from the state of the bitmap memory section 1 shown in FIG. 4 above. This is an example of a description.

The operation of the display control section 2 and DMAC 5 for generating the state of the screen memory section 3 shown in FIG. 6 above from the state of the bitmap memory section 1 shown in FIG. 4 described above will now be described.

The display control unit 2 checks the display priorities PR, , PR2, and P'R3 of the display control information held, and if the relationship of PRI<PRz<PR3 exists as described above, the display priority The lowest rectangular image pattern I of
For P, the process described below is performed.

First, the area determining section 4 instructs the DMAC 6 to transfer this rectangular image pattern IP+ from the bitmap memory section 1 to the screen memory section 3. In this case, among the control information regarding the rectangular image pattern IP, the above position XI r Yl + size hI
+vl and the position α0 on the screen memory section 3.
Information about β1 is given to DMAC6, and this
The MAC 6 places the rectangular image pattern IP in the bitmap memory section 1 at a position α in the screen memory section 3.

The data is controlled to be transferred to β1.

As mentioned above, the rectangular image pattern IP+ whose transfer has already been completed in the screen memory section 3
Rectangular image pattern IP in a position that overlaps with
2 is transferred, the overlapping part is I
The image pattern portion of P2 is given priority, and the image pattern portion of IP, which was already held in that portion, is replaced by a new rectangular image pattern IPz.

A rectangular image pattern Ipg created in this way
After the transfer is completed, the area discriminator 4 performs the same operation as described above for the next rectangular image pattern IP,l, and the screen memory unit 3 becomes in a state as shown in FIG.
Three overlapping rectangular image patterns are displayed on the display screen of the CRT 7.

Next, as an example of changing the display screen of the CRT 7, as a result of changing the contents of the rectangular image pattern IP in the bitmap memory section l shown in FIG. 4 above, the screen memory section 3 shown in FIG. The operation of the area determination unit 4 when updating the pattern IP2 will be explained.

FIG. 7 shows the state of the bitmap memory unit 1 after changing the part of the rectangular image pattern stored in the bitmap memory unit 1. In this example, a line pattern is created inside the rectangular image pattern IPz. This shows how it has been added.

FIG. 8 shows the state of the screen memory section 3 after the result of the partial change to the rectangular image pattern IP2 in the above-mentioned bitmap memory section 1 has been updated to the screen memory section 3.

At this time, the area determination unit 4 determines the position in the changed rectangular image pattern lP2O bitmap memo 9 part 1;
The size and position in the screen memory section 3 are read from the display control section 2, data corresponding to the rectangular image pattern I'Pz is displayed from the bitmap memory section 1 to the screen memory section 3, the priority order is checked, and the The updating of the screen memory unit 3 is completed by performing the same operation on all rectangular image patterns having a high display priority according to the display priority.

Conventionally, in this type of display device, a bitmap memory section 1. In order to minimize the amount of data transferred between the screen memory sections 3, as shown in FIG. The area discriminator 4 divides the area into small rectangles that do not match, and uses the display control information in the display control unit 2 to determine the size of the small rectangle (m, "-'m") that needs to be changed.
s). In this conventional example, the DMAC 5 is instructed to transfer the small rectangles m, to m8 in FIG. 8 from the bitmap memory section 1 to the screen memory section 3.

[Problem that the invention seeks to solve]

In the above-mentioned conventional display device of this type, by changing a part of the rectangular image pattern in the bitmap memory section 1, when updating the rectangular image pattern in the screen memory section 3, The entire area of the rectangular image pattern is
Since the data is transferred from the bitmap memory section 1, there is a drawback that the amount of data transferred from the bitmap memory section 1 to the screen memory section 3 is larger than that for the actual changed portion=8~.

This invention was made to solve the above-mentioned drawbacks, and when a part of the image pattern stored in the bitmap memory section 1 is changed, the result of the change is transferred to the screen memory section 3. The purpose of this is to reduce processing time by reducing the amount of data to be transferred when transferring to the corresponding part.

[Means for solving problems]

Therefore, when a partial change in the rectangular image pattern held in the first memory section 1 is reflected in the second memory section 3, the present invention detects the position of the portion of the first memory section where the change occurs. The present invention is characterized in that it is provided with a change range extraction section 8 that transfers the minimum necessary rectangular image pattern to the second margin section based on the detection of this position.

[Effect]

When a partial change occurs in the rectangular image pattern held in the first memory unit 1, the change range extraction unit 8 detects the position of the changed part. Based on this position detection, the minimum necessary rectangular image pattern is transferred to the second memory section 3.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

Note that the same components as in the prior art are given the same numbers and their explanations are omitted.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 8 indicates a partial modification of a rectangular image pattern held in a bitmap memory section 1 as a first memory section.
When reflecting in the screen memory section 3 as a memory section, the position of the part of the bitmap memory section 1 where the change occurs is detected, and based on the detection of this position, the minimum necessary rectangular image pattern is stored in the screen memory section 3. This is a change range extraction unit to be transferred.

Next, the operation will be explained.

FIG. 2 shows the state of the corresponding screen memory section 3 after the change when a line segment pattern is added to a part of the rectangular image pattern on the bitmap memory section 1.

In this example, the change range extraction unit 8 extracts the coordinates of both ends of the added line segment pattern from the position of the rectangular image pattern on the bitmap memory unit 1 stored in the display control unit 2 and the position of the rectangular image pattern on the screen memory unit 3. The coordinate values (α21.β2.), (
α22. β2□).

Next, compare the α value and β value of the two coordinate values, and according to the size, α1lifl + αIIIIIIX + βl
,,in + β□8, (αmin + β
ntn), (αIIIX + β,, t) are output to the area determination unit 4 as change range area values.

The area determination unit 4 calculates the change range area value ((αi1...βwain) +(
α□tsu, β□8. )) is divided into small rectangular areas that do not overlap each other using the image pattern arrangement information on the screen memory unit 3 stored in the display control unit 2, and A determination is made using the same procedure as in the prior art, and an instruction is given to the DMAC 5 to transfer the image pattern corresponding to the required small rectangular area from the bitmap memory section 1 to the screen memory section 3.

Further, in the above embodiment, the case where a line segment pattern is added to the original image pattern has been explained, but the added pattern may have other formats, and the image pattern to be changed may be stored in the screen memory section 3. The coordinates are (α
0. β, ), (α2゜β2), -・-, the smallest of these coordinate values (α□7.β1.i,,)
If the maximum value (αpaX+β73X) is combined to form the change range area value, the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, when a partial change in the rectangular image pattern held in the first memory section is reflected in the second memory section, the portion of the first memory section where the change occurs is Since the modified box enclosure extractor 8 is provided which detects the position and transfers the minimum necessary rectangular image pattern to the second memory section based on the detected position, the amount of data to be transferred can be reduced, and the above-mentioned This has the effect of reducing the time required for operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a display device according to an embodiment of the present invention, and FIG. 2 shows a state in which the contents of the corresponding screen memory section are changed as a result of changing a part of the rectangular image pattern on the bitmap memory section. 3 is a block diagram of a conventional display device, FIG. 4 is a diagram showing a plurality of rectangular image patterns stored on a bitmap memory section, and FIG. 5 is a diagram showing a plurality of rectangular image patterns, FIG. 6 is a diagram showing an example of display control information stored in the display control section. FIG. FIG. 8 is a diagram showing a state in which a part of the image pattern has been changed, and FIG. 8 is a diagram showing a state in which the screen memory section is divided into small rectangles. In the figure, 1 is a bitmap memory section (memory sections 1-14~), 2 is a display control section, 3 is a screen memory section (second memory section), 4 is an area discrimination section, and 5 is a direct memory access section. a controller section, 6 a video control section;
7 is a cathode ray tube, and 8 is a change range extraction section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa (and 2 others) -15 = history - history. (Spontaneous writing of procedural amendments) Showa year, month, day, 62° 1111, device for displaying the name of the invention 3, person making the amendment 5, detailed description of the invention to be amended, brief description of the drawings, drawing column. 6. Contents of the amendment (1) On page 5, line 17 of the specification, “Figure 6” has been replaced with “
Figure 5” is corrected. (2) rDMAC6, page 6, lines 8 and 13 of the same book.”
Correct that to rDMAC5J. (3) On page 8 of the same book, line 4, “Figure 8” was replaced with “Figure 9.”
Correct it to "Fig." (4) In the same book, page 14, line 18 to line 1, line 19, the phrase ``This is a diagram showing.'' was replaced with ``A figure showing.'' Yes,” he corrected. C5)■ side, Kayari II i 9JII dedication, Noshikari Oikarosuru, ysu'ni

Claims (3)

[Claims] (1) A necessary rectangular pattern is extracted from a first memory section holding a plurality of rectangular image patterns and transferred to a predetermined position in a second memory section, and based on the image pattern held in the second memory section. In a display device that generates a video signal using a display device, when a partial change of the rectangular image pattern held in the first memory section is reflected in a second memory section, the portion of the first memory section where the change occurs is reflected. 1. A display device comprising a change range extracting section that detects a position and transfers a minimum necessary rectangular image pattern to a second memory section based on the detected position. (2) The display device according to claim 1, characterized in that a bitmap memory section is used as the first memory section. (3) The display device according to claim 1, characterized in that a screen memory section is used as the second memory section.