JPS5930587A - Crt display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CRT display device, particularly a CR'l' display device for displaying characters and symbols including kanji.
, When displaying characters, symbols, etc. using a T display device,
For example, if the displayed object contains only alphanumeric characters, kana characters, symbols, and simple kanji, the character code should be 256, which consists of 8 bits (1 byte).
A seed code can be used. It is sufficient to establish a certain correspondence between each code and the characters/symbols to be displayed in advance, and to prepare a character generator accordingly.

This characterizing energizer is generally composed of l(, OM (read only memory)) and has 256 different memory addresses corresponding to the 8-bit code mentioned above, and each memory address is indicated by the code corresponding to that memory address. The dot-bang character is stored.

If we use, for example, 12 dots in the horizontal direction and 16 dots (16 lines) in the vertical direction to represent the - character, then 192 dots are required for each character, and to represent this, the character generator described above is used. Each of the 256 memory addresses has a storage capacity of 192 bits.

Now, a CRT display device is generally equipped with a refresh memory, in which each character/symbol to be displayed is stored in the form of an 8-bit character code as described above in an order corresponding to the screen to be displayed. ing. Each character code is
The character code is read from the refresh memory in synchronization with the scanning of the CRT beam, and the memory address of the above-mentioned character generator 1% OM is specified by the read character code. Thus, in synchronization with the scanning of the T-beam, the aforementioned dot bang read from this ROM is converted into a bit-serial video signal through a parallel-to-serial conversion circuit and displayed as a character bang.

For example, if each character consists of 16 dots in the vertical direction (-the number of lines of the character is 16), there is a -
In order to display a character, the memory address in the ROM storing the character must be accessed 16 times at intervals synchronous with scanning.

When accessing for the first time, read out the dot pattern of the first line of the famous confectionery with that character.1. A: At the second access, the dot button on the second line of the same memory address is read. In this way, all the lines up to the 16th line are read out at intervals in synchronization with the scanning of the beam, thereby completing the display of that one character. Therefore, the character generator reads the contents using both the memory address (character address) for specifying the character and the line address for specifying which line of the character is currently to be read. Furthermore, reading out the character code from the above-mentioned graph V-touch memory and reading out the above-mentioned dot pattern from the character generator are all carried out in a specific time order in synchronization with the CR and T beam scanning, but these readout signals LS to create
Integrated CR, T controllers are widely used.

Now, if the number of characters to be displayed is limited as mentioned above, a 1-byte code with 256 types is sufficient, but
A 2-byte code is generally used to include all the kanji that are used on a daily basis.

That is, in this case, each character to be displayed is all represented by two bytes. In this way, a total of 216 = 65,536 different characters can be displayed0 In addition, in this case, the number of dots per character is generally reduced compared to the above case so that even complex kanji can be displayed with sufficient fidelity. A sufficiently large value is used. For this purpose, CI
(The /...-ware of the T display device is more complex, and because the number of dots used per - character is large, the number of characters that can be displayed on one screen is also reduced.

However, depending on the purpose, such as the CR, T device 4 used as a terminal device for specific tasks, it may be necessary to display kanji, but it is not necessary to include all kanji that are used on a daily basis. It often happens that it is insufficient to specify the t-2564 code for all display characters, including the -C1 kanji.

In this case, if we completely ignore existing technology, ′? Depending on the case, it is also possible to use a character code with the number of bits that best suits the type of character to be displayed.

However, for example, whether it is the aforementioned CRT controller LSI, or RAM or ROM, it is generally convenient to use bytes as the basic unit, so it is not necessary to ignore this. Sushi cannot be an effective method either. An object of the present invention is to provide a CRT display device that is well suited for the above-mentioned uses, taking existing systems into consideration.

C) The device of the present invention is a LT display device for displaying characters and symbols, and the characters and symbols to be displayed are divided into a ml group and a second group, and the first group is displayed. The target is specified by the first group designation code using a part of the code consisting of l / 1 byte code excluding the 1st group specification code and the 1 byte 2nd code added to it
Consists of part-time jobs! refresh memory means for storing all the first group designation codes and the second group finger/foot codes for display objects to be displayed on one screen of the CRT display device t, which are designated using two group designation codes; , two register means for storing two successive bytes read from the refresh memory means, and a byte read into the register means is the first group designation code or the second group designation code. a decoder means for identifying whether it is one byte, and if the byte stored in a predetermined one of the two register means β is the first group designation code, it is designated by the code; If the 2 bytes stored in the two register means is one of the second group designation codes, display the display target of the second group specified by the code. The entire display for the first group of display objects is displayed in the display area for two of the display objects for the first group.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

This embodiment is a CRT display device used for a specific business terminal device, and is a CRT controller/controller (CRT C) 2.
e including tr control ss (CONT)t, y' Direct memory access controller (DΔiAC) 3, refresh memory (R1i'M) 4, second register (F
RG) 5, second register (S R,G'>6,
Decoder (DEC) 7, non-kanji character generator (NCHR()) 8, kanji character generator (K
CHu(1) 9, non-kanji dot shift register (N
St(,)tO1 Kanji dotnft register (KS 几)
it, switching selection circuit (SW) 12, bidet, Hfi number processing 1i? IM (VPC) l 3, C) LT deflection circuit (
DEL") l 4, and a CR including a deflection coil,
It has a T (candle tube) 15.

In this embodiment, refresh memory 4 (hereinafter referred to as
The 1/R report stored in M4) is displayed as a video on the screen of C-T15. Therefore, @ for 1 to be displayed is written in advance to RlL"M4 from the outside using the address node 300 and data bus 400. In this case, the characters and symbols to be displayed are approximately F M , i is specified. The address areas are configured as described above in the order in which they are displayed.

First, the displayed characters/symbols are alphabetic characters (A, B.

C1...Z), numbers (0, 1, 2,...9), kana characters (a, i, tsu,...n), symbols (space us"v
, (, ), ..., etc.) and about 1,000 kanji (including hiragana! From now on, all hiragana are included in kanji), and the character codes for these are as follows. Assigned as follows.

Kanji f among the above characters and symbols, except for alphabetical characters and numbers.

For kana characters and symbols (hereinafter referred to as non-kanji, but not including hiragana), the 8-pinto (1-byte) character code t [2 figures, i.e., each bit of the 8-bit code is From bl, b2. ...bs
This is divided into lower digits and upper digits of 4 bits each, and this upper F? 7 (bs~bs) and lower digits (
bl~b4) respectively o, 1°2.3. ...9. A
, B, C, D, E, F, the 8-bit character code assigned to each non-kanji character can be expressed as 21 lines of hexadecimal numbers, as shown in FIG. for example,
The number 6 is assigned the character code 3614 (H indicates hexadecimal representation), the alphabetic character P is assigned the character code 50) (but the kana character is assigned the character code BFH).
However, the character code 2B)I is assigned to the symbol 10.

As is clear from FIG. 2, even if assignments are made to these non-kanji characters, the characters are still OOH~lli'')I.

One byte codes 60H to 9FH and EOH to FF'H remain unallocated. However, even if this remaining 1-byte code is totaled, 16X8=128
This alone is insufficient to allocate the approximately 1,000 Kanji characters required in this embodiment.

Therefore, in this embodiment, as described above, character codes of 8 bits (1 byte) are assigned as is to non-kanji characters according to Figure 2, and the remaining 1 byte code is Then, add the second byte and print the resulting 2-byte code on one kanji character code to make it a kanji character code.The maximum number of kanji character codes is 256 x 128 = 32768, which is the required number. This will sufficiently exceed the above. There are 1,040 kanji character codes that are actually used! By restricting the characters to similar characters, only Kanji character codes that are easy to identify can be used.

FIG. 3 shows an example of character codes for kanji characters assigned in this manner. In this example, the top four pits of the first byte and the top four pits of the second byte are the same number (
In this example, the city is 1 tear so that E)K.

Even with such restrictions, the character code for the first byte is 5Ql-1 to 6 FH.

70H~7FH, EUH~EF'H o, l: biF'OH
~ 2 by simply using the 4 columns in Figure 2 of FF'H
56×4=1024 kanji can be specified.

In this embodiment, the FM4 contains a 1-byte character code representing a non-kanji character (hereinafter referred to as a non-kanji character code) assigned as described above, and a 2-byte character code representing a kanji character (hereinafter referred to as a kanji character code). Character codes) are stored according to the order of characters to be displayed.

The above-mentioned non-kanji and kanji characters are displayed on the C-T15 screen as follows.

Each character is displayed in a dot pattern, and the dot pattern/character area allocated to non-kanji characters is 11 dots in the horizontal direction and 22 dots in the vertical direction.

On the other hand, the area allocated to kanji is 22 in the horizontal direction.
The area of kanji is 22 dots in the vertical direction, and the area of kanji occupies twice as much area in the horizontal direction as that of non-kanji.

In this example, by selecting twice the number of dots for one kanji character area as for non-kanji characters,
With a relatively simple hardware configuration, it is possible to display kanji in sufficiently high quality without unnecessarily increasing the number of dots for non-kanji (and therefore reducing the number of non-kanji characters that can be accommodated on one screen). ing.

These characters are displayed on the CIl'LT screen by scanning the CRT beam, but this will be explained later.

In the horizontal direction, the time taken by the T beam to scan one pit is expressed as CI (TI), and similarly when one non-kanji area is horizontally scanned, 1i5 (TsumapTl) x 1l) eTN
Let us express it as In this way, the time required to horizontally scan the kanji area is TDx22=2TN.

Note that the above-mentioned number of dots indicates the number of dots in the area for each character, and the number of dots for the actual character portion used in the character generators 8 and 9 is selected to be smaller than this.

Now, each of the above-mentioned character codes stored in RFiV4 and each of the above-mentioned areas on the screen of CT15,
The operation of this embodiment for displaying non-kanji characters and kanji characters is as follows.

The control unit l includes a clock oscillation a (not shown),
The reference clock generated here is transferred to the CRT controller 2 (
Thereafter, the C voltage rc2 is frequency-divided by t' using various counter circuits to generate various mutually synchronized 1ljIII111 signals.

First, a horizontal drive signal (HD signal) 108 is generated, which is supplied to the CRT deflection circuit (1) EF) 14, and C1(
, T15. Similarly, scanning in the vertical direction is controlled by a vertical drive signal (VD) 109. In this way, the scanning of C'r15 is changed to C1(
Since the drive signal generated by Te3 causes the control unit 1 to move to the side, the control unit
The dot at position q can be specified as a pulse generated at a specific time interval from each of the horizontal and vertical drive signals.

Now, when the control unit l finishes displaying a certain -4 line, it starts the direct memory access controller 3 (hereinafter referred to as DMAC3).
DM via the DMA request line (DRQ) tlo
A issues a transfer request. When you receive this, DMAC5
transfers information including predetermined character codes for one line from R, FM4 to data bus 40 by DMA transfer.
The row buffer contained within CRTC2 via 01c (
(not shown). The CTO2 is equipped with two sets of such line buffers, and while one line buffer is being used for reading to display the current line, the other line is being read out after the previous line has been displayed. The next line of information is stored in the buffer by DMA transfer.

Thus, the two sets of row buffers are mutually used for reading for display. The character codes in the bulletins stored in these line buffers are scanned by the CRT 15 screen.
This row buffer is read periodically, as described below. These are stored in an external register via data output line 100 and are used to specify the character to be displayed.

Now, about 'I'N before the scanning beam starts scanning the first point (leftmost) of the active screen in a row,
The first byte of character code for this line is read from the line buffer via output line 100. This is a character clock (CChK) 1 whose period is TN.
01, the second register (FRG) with 8-bit width
It is latched to 5. Note that the contents previously stored in the register 5 are shifted (transfer latched) to the second register (SLLG) 6, which also has an 8-bit width, by the same clock 101.

If TN passes further from this point, clock 10
1 appears, which causes the first byte stored in the register 5 to be transferred to the second register 6 and the second byte to be transferred from the row buffer to the register 5, as described above. 5 and is read and stored. The first byte character code stored in the second register 6 is read M by the decoder 7, and it is determined whether it is a non-kanji character code or a kanji character code in the first byte, and this identification result is controlled as a detection signal 700. It is supplied to part l.

On the other hand, the 8-pit output of the character code stored in the second register 6 is output from the non-kanji character generator (
NCHRG) 8 as character addressing data, and on the other hand Kanji character generator f (KCHR
G) 9 is supplied as the first byte data for character addressing. Further, the character code of the second byte of this line stored in the first register 5 is supplied as second byte data for specifying a character address to the same Kanji character generator 9. Along with this, 5-bit data is supplied from CR, Te3 as data for specifying the line address of both character generators 8 and 9 via the line address output (LAD) 102 of the control vAt, indicating the character to be currently read. Specifies whether the dot pattern on the dark side line should be read out.

As a result, if the character code C stored in the second register 6 is a non-Kanji character, the correct non-Kanji dot line & (11 pit) specified by this character code is a non-Kanji character. It is output from the generator 8 and established on the preset input side of the non-kanji shift register NSK10, which is composed of an 11-bit shift register.

Also, if the character code stored in the second register 6 is the first byte of the Kanji character code, f
One line of correct kanji dot patterns specified by the 2-byte contents of J2 register 6 and ill register 5 (2
2 bits) is the Kanji character generator (, KCHR
G) is read from 9 and established at the preset input side of the Kanji Shift Register (KSR), which is read from 22-bit shift register (11).

Now, immediately after the first byte is stored in the second register 6 by the clock 101, the control 1flSt checks the detection signal 700 supplied from the decoder 7,
If this indicates a non-Kanji character code, a preset signal NP8103 is immediately generated and the non-Kanji shift register 1OIJ is turned off. At the same time, a selection signal (SEL) is sent so that the switching selection circuit (8W) 12 selects the output of the non-kanji shift register 101111.
) 106.

If the detection signal 700 indicates the first byte of the Kanji character code, the preset signal (
KPS) 104 and Kanji shift register (t<5
a) Data for l lines of the above-mentioned kanji dot pattern established on the input side of ti is preset in the shift register 11. At the same time, the circuit 12 selects the output of the kanji shift register 11 by setting the selection signal 106.

Shift registers 10 and 11 are supplied with a dot clock (DCLK) 10 having a period of TD as a 7-ft pulse.
5 is supplied. As a result, in any of the above cases, on the screen of the CEL'lJs, the scanning beam starts scanning horizontally from the left edge of the active screen, and the correct character video output for the first character code is at the 7 foot register 10 or 11 is read bit serially,
The correct one of them is selected by the circuit 12 and sent to the video signal processing circuit (VPC) as the character video signal 1200.
13.

As mentioned above, the 1917 dot patterns for kanji include twice as many dots as the 124 dot patterns for non-kanji, so the character video signal 1200 for kanji has twice the length of the character video signal 1200 for non-kanji. , Therefore, on the 081 screen, it will be displayed in twice the horizontal area.

Note that when the detection result of the detection signal 700 described above indicates a non-kanji character, the control unit 1 performs the next check 'i!' on the detection signal 700. After 1-TN (Tsumashi, clock lot
(Immediately after the 1 byte for the 9th character code is stored in the second register 6) (this is done at intervals of TN), but if the detection result indicates a kanji,
The next check for the detection signal 700 will be after 2TN (that is, immediately after the 1 byte for the next character code of this Kanji character code is stored in the second register 6 by the clock lot). I won't do it until then. By doing this, it is possible to successively and efficiently identify whether the code is a non-Kanji character code or the first byte of a Kanji character code. Further, the above-mentioned character video signal 1200 is continuously outputted one after another.

Now, when displaying characters on the 081 screen, it is possible to perform various modifications such as underlining, blinking, or reversing white and black for specific characters. It is. 1 Cape information for performing these modifications is 几FM 4 as well as the character code.
It is stored in a specific area in the line buffer (attribute area), and when the character code is transferred and stored in the line buffer in DMA transfer, it is transferred along with it and stored in a specific area (attribute area) in the line buffer. . These information are also read out from the row buffer according to the scanning of the beam, Ct(,T
It is processed inside D2, and as a result, it is converted into a time signal (signal whose output changes with time) convenient for performing each function, and is sent via the modified signal output line 107 of the control unit l. The signal is supplied to the video signal processing circuit 13.

In the circuit 13, the supplied character video signal 1
200 and these modification signals, depending on the modification function, logical sum (processing such as unlining), logical product (elimination of unnecessary parts, etc.), and exclusive logical sum (blinking, etc.)
A specified modification is added to the character video signal 1200 by processing such as reverse processing), and the video signal 13 is
00 and is supplied to the brightness modulation terminal of OR and T15. Note that the modification signal 107 also includes a symbol for erasing horizontal and vertical scanning retrace lines and a signal for erasing unnecessary portions outside the effective display screen.

In this way, the specified characters are correctly displayed on the screen of the CT 15 with the specified modification.

In addition, in the above explanation, we have explained in detail how one line with the first character code of a certain line is displayed as an image, but it will be clear from the other lines and the second explanation. .

As described above, according to this embodiment, alphabetic characters.

For numbers, kana characters, and symbols, 1-byte codes based on the conventional JIS (Japan Industry Association Standards) are used, and for kanji (including hiragana), the above-mentioned alphabetic characters, By using the 2-byte code generated by the remaining code for numbers, kana characters, and symbols and another 1-byte code added to this code, we can solve the problem by adding a relatively small amount of hardware. The kanji designation of Ij
To increase the display dot a only for kanji with a complex character structure without increasing the number of display dots for alphabetic characters, a characters, kana characters, and symbols with simple character structures. It is possible to provide an at7T display device that enables.

In addition, the controller 2 of the first row of this embodiment uses a commercially available LSI circuit (LSI), and the control unit 1 can be realized by simply adding a relatively simple external circuit to it. I can do it. Also l) MA controller 3 is also LS
Commercially available I-formed products can be used. Character generators 8 and 9 are R, OM t is EPR, 0
+J (i! replacement, ti'l capable ROM) can be configured using i. In particular, an existing character generator 8 may be used depending on the case (the dot pattern in the portion corresponding to the first byte of the Kanji character code is not displayed even if it is read). The Kanji character generator 9 can have various configurations depending on the number of vertical and horizontal dots of the characters to be actually displayed and the number of characters to be accommodated. It can be easily realized using O1'J or ROM.

In this embodiment, as is clear from FIG. 2, all non-kanji character codes are set to the g6th bit (
b6) and the seventh bit (b7) are different, so as shown in Figure 4, the 64th bit (b6) of the second register 6 is exclusive with the seventh bit (b7). The decoder 7 that easily detects this can be implemented by calculating the logical sum.

The refresh memory (RF'M4) can also be performed using a specific area of the main memory of the terminal device.

Furthermore, the circuit configuration, the method of assigning character codes, the number of dots in the area for displaying each character, etc. of this embodiment described above are merely an example, and are not limited thereto. .

As described above, by using the present invention, alphabetic characters, numbers, and kana characters can be created using relatively simple hardware.

Cl(, '
r display device t can be realized.

As a result, CR suitable for the terminal device t used for specific business,
T display device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining character code assignment in this embodiment, and FIG. 4 is a circuit diagram of a decoder in this embodiment. It is a figure which shows an example. In the figure, l... control unit (CONT), 2.
...CT controller (CR, TO)% 3.
...Direct memory access controller (1
) MAC), 4... Refresh memory (R,
FM), 5...... No. 1 (F Re ), 6
...Second register (SR()), 7...
・Decoder (DEC), 8...Non-Kanji character generator (NC) I几G), 9...Kanji character generator (KCI(l(,G), 10...
...Non-kanji dot shift register (NS几), 1
1...Kanji dot shift register (KS 几),
12...Switching selection circuit (SW), 13...
...Video signal processing circuit (vPC), 14...
C T deflection circuit (DEF), l 5...Cf (
, T (Kandray tube). Agent Patent Attorney Hara Uchi 1.・-′;11,
・l 1st eye 2nd eye 3rd eye 4th eye

Claims (1)

[Claims] In a CRT display device for displaying characters and symbols, the character fist symbols to be displayed are divided into a first group and a second group, and the display target of the previous first group is divided into a first group and a second group. is specified by a first group designation code using a part of a 1-byte code, and for the display target of the second group, the first group of the 1-byte code is specified. The display to be displayed on one screen of the CRT display device is specified using the second group specification code, which is made up of a 1-byte code excluding the specification code and 1 second byte added to it. ref7:L memory means for storing all the ml group designation codes and the second group designation code for the object; and 2 memory means for storing two successive bytes read from the refref/S memo 9 means. and decoder means for identifying whether the byte read into the register means is the first byte of the first group designation code or the first byte of the second group designation code, of the two register means d. If the byte stored in one of the predetermined register means is the first group designation code, display is performed for the display target of the 41 groups designated by the code, and the byte stored in the two register means is displayed. If 2 bytes is one of the second group designation codes, display the display for the second group display objects specified by the code in the display area for two of the displays for the first group display objects. A CRT display device characterized by: