JPH04124292U - display device - Google Patents

Abstract

(57) [Summary] [Purpose] To display characters and illustrations using approximately the same number of scanning lines as that of a CRT display that performs interlaced scanning and displays images. [Structure] An even field image memory 3a, an odd field image memory 3b, a synchronization signal field determination circuit 2 that determines whether it is an even field scan or an odd field scan from a synchronization signal, and a synchronization signal field determination circuit 2.
In response to the determination result, whether the even field image memory 3a is accessed or the odd field image memory 3a is accessed.
Access selection means 4 is provided for selecting whether to access b.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention provides text in images displayed using image data from an image recording device such as a video. It relates to a display device that can display overlapping characters and illustrations on the same screen.

0002

[Conventional technology]

FIG. 5 is an explanatory diagram showing the concept of the NTSC display method. Display devices such as CRT displays mainly use the NTSC system, and video Image recording devices such as The information is sent to a display device and converted into visually visible information. Here, a display device such as a CRT display normally has 525 scanning lines. The image is displayed using interlaced scanning, which scans every other line. . To simplify the principle, first, for 525 scanning lines, It scans every other line to create a coarse image with about half the number of scanning lines to form an even field. The scan lines located between the scan lines scanned in the first scan are scanned for the second time. After all, a coarse image with about half the number of scanning lines is illuminated to form an odd field, and these One frame is completed by combining even and odd fields, and this is one frame. will be displayed on the display as a screen.

0003 Currently, there are no devices available for displaying text and illustrations on display devices such as CRT displays. A character illustration image memory is provided to store data from an image recording device such as a video. Text and illustrations can be added to the NTSC image displayed by the incoming NTSC signal. It is now possible to display overlapping images, and Figure 6 shows text on an NTSC image. FIG. 2 is an explanatory diagram showing a conventional display state in which character illustration images are displayed in an overlapping manner. For example, the character "H" is stored as an image in the character illustration image memory in Figure 6 ( Character illustration image data as shown in a) is stored. This letter “H” is divided into two fields, an even field and an odd field. The above-mentioned NTSC image is displayed by completing one frame from the If you want to display the character illustration image superimposed on the Access the memory, read the character illustration image data, and select the even field. superimposed on the NTSC image data at the time of scanning. Next, access the character illustration image memory again when scanning an odd field. Read out the same character illustration image data as when scanning an even field, and It is superimposed on the NTSC image data when scanning several fields. Then, by combining the even and odd fields, one frame is Completed, text illustration image and NTSC image are superimposed on the same screen of the display. displayed. At this time, the display of characters is as shown in Figure 6(b). The same character illustration image in the scanning line during field scanning and the scanning line during odd field scanning The image data will be displayed.

0004

[Problem that the idea aims to solve]

In this way, when displaying a character illustration image overlaid on an NTSC image, The same character illustration image during field scanning and odd field scanning By accessing the data, you can run twice using the same character illustration image data. The scan line and odd field scan line located next to each other are The same character illustration image data is displayed on the scan line during field scanning. Therefore, character illustration image data usually has about 250 lines (NT) in the vertical direction. Display can only be performed using approximately half the number of scanning lines in an SC image. There is a problem in that the image becomes coarse when displaying detailed information. In addition, the shape imaged on the character illustration image memory will be stretched twice vertically. The actual shape that will be displayed will be calculated in advance. The problem is that data must be created using

[0005] As mentioned above, in this invention, a character illustration image has the number of scanning lines in an NTSC image. It can only display about 250 lines, which is about half of that, and is too coarse to display detailed information. Also, the shape imaged on the character illustration image memory will be doubled vertically. Since it will be displayed in an expanded form, the actual shape that will be displayed should be calculated in advance and the data created. This was done to solve problems such as having to make an even number frame. Separate character illustration image data during field scanning and odd field scanning By using a character illustration image, the number of scanning lines in an NTSC image is approximately the same as that of an NTSC image. To provide a display device capable of displaying using approximately 500 lines, which is approximately equivalent to the number of lines. With the goal.

[0006]

[Means to solve the problem]

To achieve this objective, the present invention performs interlaced scanning on multiple scanning lines. One frame is made up of the even and odd fields formed by Image data, text and illustrations to provide a completed moving or static image. text illustration image data that is independent of the image data for providing text. In a display device that displays images on the same screen of a CRT display, Character illustration image data that is superimposed on image data when scanning several fields Even field image memory stores data and image memory during odd field scanning. The even number field stores character illustration image data to be superimposed on the image data. The odd field image memory is independent of the field image memory, and the odd field image memory is separate from the image data. Determine whether it is even field scanning or odd field scanning from the synchronization signal received. In the synchronization signal field determination circuit and the synchronization signal field determination circuit, even When it is determined that it is scanning several fields, the image memory for even fields is to access the character illustration image data, and when scanning an odd field. If it is determined, the character illustration image data is stored in the odd field image memory. It is characterized by providing an access selection means for making access.

[0007]

[Effect]

The present invention having the above-described configuration is capable of processing image data from an image recording device such as a video. When displaying text or illustrations superimposed on an image, they are separated from the image data. It is determined from the synchronization signal that the even number field is scanned or the odd number field is scanned. During field scanning, even field image memory is accessed; When scanning several fields, the odd field image memory is accessed. . The read character illustration image data is then superimposed on the image data, It will be displayed on the same screen of the CRT display. In this way, when even field scanning is performed using image data, the even field image Read character image image data from memory, and when scanning an odd field Character image image data can be read from the field image memory.

[0008]

【Example】

Examples will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of a display device showing an embodiment of the present invention. 1 is a CRT display that displays images in the NTSC format, and the received NTSC an NTSC decoder 1a that separates the signal into a synchronization signal and NTSC image data; NTSC image data separated by NTSC decoder 1a and character image described later It consists of a superimposition circuit 1b that superimposes image data. 2 is a synchronization signal field determination circuit, which is separated by the NTSC decoder 1a. Receive the synchronization signal of the NTSC signal and use this signal to scan even field. outputs a signal to determine whether or not odd field scanning is being performed.

[0009] 3 is a character illustration image memory, which is read out during even field scanning. An even field image memory 3a storing character illustration image data and an odd field image memory 3a storing character illustration image data; Stores character illustration image data read out during field scanning It is separated into an odd field image memory 3b. 4 is an access selection means, which selects the even field image memory during even field scanning. 3a is accessed, and when scanning an odd field, the odd field image menu is accessed. The synchronization signal field determination circuit 2 is configured to access the memory 3b. The destination to be accessed is selected based on the signals received. 5 is a display circuit which CR converts the character illustration image data in the character illustration image memory 3. Send to T-display 1. 6 is an external video signal source (laser vision video disc player, etc.) (recording device) receives the signal from the external video signal control section 7 and displays the CRT display. Send an NTSC signal to A1. 8 is a CPU that controls each section mentioned above.

0010 The field determination method in the synchronization signal field determination circuit described above is explained below. I will explain. FIG. 2 is a circuit diagram of the synchronization signal field determination circuit 2, which mainly consists of a counter and a D - Consists of flip-flops A and B. To explain each signal here, H-Sync is a horizontal synchronization signal, V-Sync c is a vertical synchronization signal. 3.25μsCLK is a clock signal with a period of 3.25μs, 50μsCLR-N is a signal that resets the flip-flop A at a period of 63.56 μs. SAMPLE F/F determines whether it is odd field scanning or even field scanning. This is the reference signal for determining the

[0011] FIG. 3 is a time chart showing changes in output of each signal over time. When the horizontal synchronization signal H-Sync is "odd field → even field" The equalization pulse interval is 3H (1H (1 raster) = 63.56μs), and the “even number field” field → odd field, it is 3.5H, and using this difference, the field It is for making judgments. According to the circuit shown in FIG. 2, the SAMPLE F/F receives the vertical synchronization signal V-Syn. If you sample at the falling edge, it will be “L” in “odd field → even field” level, EVEN becomes “H” level in “even field → odd field” -N signal is output, and using this EVEN-N signal, even field It is possible to distinguish between scanning and odd field scanning.

0012 FIG. 4 is an explanatory diagram showing a memory map of the character illustration image memory. Here, in a memory with a capacity of 32 Kbytes, even field image memory 3a and the odd field image memory 3b are set as shown in FIG. By inputting the EVEN-N signal to A5 of buses A0 to A15, "odd" Number field → even number field”, the EVEN-N signal becomes “L” level, The even field image memory 3a is accessed. Also, “even fee” field→odd field”, the EVEN-N signal becomes “H” level, and the odd field The field image memory 3b is accessed, and the access selection Means 4 will be constructed. As a result, when scanning an even field, the corresponding even field image Access is made to memory 3a, and when scanning an odd field, the corresponding odd number is accessed. Compared to the conventional method, it is possible to access the field image memory 3b. 512 lines (depending on the amount of memory used, but NTS Characters can be displayed using the number of scanning lines (close to 525 in the C method) independently. Become so.

[0013] With the above-described configuration, NTSC images and character illustrations are displayed on the CRT display 1. A method for displaying images in an overlapping manner will be described below. A command from the CPU 8 operates the external video signal source 6 via the external video signal source control section 7. Let them make it. Then, an NTSC signal is transmitted from the external video signal source 6 to the CRT display 1. be done. The NTSC signal received from the external video signal source 6 is sent to the CRT display 1. The coder 1a separates the synchronization signal and NTSC image data, and converts the synchronization signal into a synchronization signal file. It is transmitted to the field determination circuit 2. The synchronization signal determination circuit 2 that receives the synchronization signal determines whether the "odd number" "L" level for "field → even field", "L" level for "even field → odd field" In "Hold", the EVEN-N signal which becomes "H" level is output. The access selection means 4 receiving the EVEN-N signal determines that the EVEN-N signal is “L”. If the level is "H" level, it is stored in the even field image memory 3a, and if it is "H" level, it is stored in the odd field. The image memory 3b is accessed.

[0014] As a result, when scanning an even field, characters are stored from the even field image memory 3a. The illustration image data is superimposed on the CRT display 1 via the display circuit 5. When scanning an odd field, the text is sent to the image memory 3b from the odd field image memory 3b. The character illustration image data is superimposed on the CRT display 1 via the display circuit 5. The signal is sent to circuit 1b. Then, the character illustration image data sent from the display circuit 5 and the NTSC data are The NTSC image data separated by the coder 1a is superimposed by the superimposition circuit 1b. By displaying on CRT display 1, NTSC images and character illustration images can be displayed on CRT display 1. can be viewed visually on the same screen.

[0015]

[Effect of the idea]

As explained above, the present invention allows interlaced scanning to be performed on multiple scanning lines. One frame is completed by combining the even and odd fields formed by and image data to provide moving or static images, as well as text and illustrations. The image data to be provided is superimposed with character illustration image data independent of the above image data. In a display device that displays images simultaneously on the same screen of a CRT display, an even frame Character illustration image data that is superimposed on image data during field scanning even field image memory that stores the image data, and image memory that stores the image data during odd field scanning the even field for storing character illustration image data to be superimposed on the data; Odd field image memory independent of image memory and separate from image data Synchronization that determines whether it is even field scanning or odd field scanning from the synchronization signal In the signal field determination circuit and the synchronization signal field determination circuit, even number frames are When it is determined that the field is being scanned, a statement is sent to the even field image memory. Access the character illustration image data and determine that it is odd field scanning. access of character illustration image data to odd field image memory when The system is provided with an access selection means for performing the access.

[0016] Therefore, when scanning an even field using image data, the even field image Read character image image data from memory, and when scanning an odd field Character image image data can be read from field image memory. , characters are printed using approximately 500 lines, which is close to the 525 scanning lines of a CRT display. You can now display detailed and beautiful character illustration images. In addition, a large number of lines can be used independently, so a large amount of detailed information can be stored. It has the effect of displaying information. In addition, the character illustration display is not enlarged twice vertically, so the character illustration When creating text image data, take into consideration that it will be enlarged twice in the vertical direction when actually displayed. There is no need to perform extra calculations, reducing the time required to create character illustration image data. It has the effect of being able to

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a display device showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a synchronization signal field determination circuit.

FIG. 3 is a time chart showing changes in each signal in FIG. 2;

FIG. 4 is a memory map of a character illustration image memory.

FIG. 5 is an explanatory diagram showing the concept of the NTSC display method.

FIG. 6 is an explanatory diagram showing a conventional display state of character illustration image data.

[Brief explanation of symbols]

1 CRT display 2 Synchronous signal field determination circuit 3a Even field image memory 3b Odd field image memory 4 Access selection means

Claims (1)

[Scope of utility model registration request] Claim 1: Image data for providing a moving or static image in which one frame is completed by combining even and odd fields formed by performing interlaced scanning on a plurality of scanning lines. , in a display device that superimposes character illustration image data independent of the image data for providing characters and illustrations and displays them on the same screen of a CRT display, characters that are superimposed with image data during even field scanning; An even field image memory for storing illustration image data, an odd field image memory independent from the even field image memory for storing character illustration image data to be superimposed on image data during odd field scanning, and an odd field image memory separated from the image data. A synchronization signal field determination circuit determines whether it is an even field scan or an odd field scan based on the synchronization signal, and if the synchronization signal field determination circuit determines that it is an even field scan, the even field image memory is The present invention is characterized in that an access selection means is provided for causing the character illustration image data to be accessed to the odd field image memory, and for causing the character illustration image data to be accessed to the odd field image memory when it is determined that it is odd field scanning. display device.