JPH0131198B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a display device.

When displaying data input from an input device such as a keyboard on a display device such as a cathode ray tube (hereinafter referred to as CRT), or when performing calculations on input data and displaying the results, the following A cursor is displayed to indicate the display position of the cursor, and an object of the present invention is to provide a display device in which the cursor display is easier to see and the device itself is improved more economically.

Conventionally, this type of display, as shown in Figure 1,
Only the next display position was displayed as a black square flash, or the next display position was displayed as an underline. However, the latter underline display requires a circuit for underline display, which is disadvantageous in terms of cost.
In addition, with the former black square display, when you move the cursor to a position where a displayed character is, the displayed character up to that point is erased to display the cursor, making it extremely difficult to use. Ta.

In view of the above points, the present invention uses a black square display as a cursor. For example, when the cursor is moved to a certain position of a displayed character, as shown in FIG. The cursor is displayed at the same time during a certain time period (T ₁ in Figure 2), and the displayed characters are displayed during another period (T ₂ in Figure 2). be.

For example, if T ₁ = 0.3 seconds and T ₂ = 0.7 seconds, 1
Since the cursor position flashes every second, the current location of the cursor becomes immediately clear, and at the same time, even if the cursor comes to a place where a displayed character is located, the displayed character is displayed without being erased. If the display period of the displayed characters is made longer than the display period of the cursor, the displayed characters will hardly become difficult to see.

Furthermore, in the present invention, both the characters and the cursor are displayed using a common storage device, and data signals for characters and data signals for the cursor are alternately written and read from the storage device. , the cursor can be displayed without using a special signal generation circuit or symbol generator.

As described above, according to the present invention, it is possible to display not only the cursor as in the conventional example, but also the cursor and characters at the same time. It does not require any special display space and is extremely economical.

Next, the specific circuit configuration and operation of the display device of the present invention will be explained with reference to FIG. Third
In the figure, 1 indicates a counter, which divides the frequency of the pulse wave input to terminal A so that it can be output from AB ₁ at the timing necessary to display it on the CRT.
AB ₂ , AB ₃ ... and so on, High Level (hereinafter referred to as "H")
). 2 indicates a selection circuit, for example, the CS line is at Low Level (hereinafter referred to as “L”).
), AD ₁ → AC ₁ and AD ₂ → AC ₂ ...
Selected to be connected to AD ₁₀ → AC ₁₀ respectively. On the other hand, if the CS line is “H”, AB ₁ →
AC ₁ is selected so that AB ₂ → AC ₂ ... AB ₁₀ → AC ₁₀ .

3 is a storage device, which is composed of storage elements that correspond one-to-one with the display position of the CRT, and these storage elements are connected to "H" and "L" of each line AC ₁ to AC ₁₀ .
It is configured such that it can be uniquely selected by a combination of. Then, for one selected storage element, when the WT line and the CS line are "L", data indicated by DT ₁ to _{DT 8} is stored,
When the WT line is “H”, the contents of the memory element are DT ₁
~It is connected so that it is output to DT ₈ . Reference numeral 4 denotes a shift register for converting the parallel data of DT ₁ to _{DT 8} into serial data for display on the CRT, and the conversion speed is determined by the pulse input to terminal B.

5 is a gate, and when displaying characters and a cursor on the CRT, the CS line and WT line are "H", so shift register 4
The output from passes through gate 5 and appears at terminal C,
This is connected to the cathode of the CRT to display characters on the CRT. That is, at this time, each line of AB ₁ to _{AB 10} , which is the output of the counter 1, is connected to AC ₁ to AC ₁₀ through the selection circuit 2, and the storage elements of the storage device 3 are sequentially selected.
It is assumed that the contents of the memory element are converted into serial data by the shift register 4 and then supplied to the CRT for display. However, if the WT line is “L”,
DT ₁ to _{DT 8} have no relation to the contents of memory element 3,
In order for the data given from the buffer circuit 7 to appear, this data is passed through the shift register 4.
When displayed on a CRT, it appears only as noise on the CRT. (This is because the phase relationship with the pulse wave at terminal A does not match) It is better that such noise does not appear on the CRT.
The gate 5 prevents this noise. In other words, when the WT line is “L”, gate 5
is closed to prevent noise from being output to terminal C.

Reference numeral 6 denotes a buffer circuit, which is inserted for connection between the selection circuit 2 and an arithmetic processing unit 8, which will be described later.

It is assumed that all data output from AD ₁ to AD ₁₀ , the CS line, and the WT line are included in the data transmitted on the AD line.
When the WT line is "L", the buffer circuit 7 outputs the data from the arithmetic processing unit 8 to DT ₁ to DT 8 through the DT line, but when the WT line is "H", it outputs the data to DT ₁ to DT ₈ . It operates to output DT ₈ data to the DT line. This is to prevent data from the buffer circuit 7 from appearing at the same time, although data from the storage device 3 appears in DT ₁ to DT ₈ when the WT line is at "H".

The arithmetic processing unit 8 described above outputs a selection signal to the AD line, and at the same time reads data from the selected device through the DT line (in this case,
It is also possible to write data to the selected device or element (the WT line becomes "L"). 9 is another storage device, which is used for arithmetic processing and temporary storage of data. 1
0 is a clock circuit that produces a fixed time, and terminal D
A pulse with a required time interval than a pulse wave of a constant frequency applied to (for example, T ₁ and
This is a circuit that produces T ₂ ).

The operation of the display device of the present invention having the circuit configuration as described above will be explained below with reference to FIGS. 2 and 3.

At time t ₁ (Figure 2), Figure 2B appears on the CRT.
A cursor will appear as shown. To display this cursor, first, the arithmetic processing unit 8 outputs a signal to the buffer circuit 6 via the AD (bus) line to select one memory element in the memory device 3 corresponding to the display position, and Set the CS line output of circuit 6 to "L" and the WT line output to "L". Since the CS line output is set to "L", the selection circuit 2 selects the output lines AD ₁ to AD ₁₀ of the buffer circuit 6 and the line to the storage device 3.
Can be switched to connect AC ₁ to AC ₁₀ .
As a result, the signal output from the arithmetic processing unit 8 for selecting the above-mentioned storage element is input to the storage device 3 through the buffer circuit 6 and the selection circuit 2. on the other hand,
The data corresponding to the cursor is sent from the arithmetic processing unit 8.
The signal is supplied to the buffer circuit 7 through the DT (bus) line.

At this time, the WT line of the buffer circuit 6 is “L”
, the gate 5 is closed and the read output of the storage device 3 is closed, and the storage device 3
is set to a so-called write mode. Line AC ₁ ~ in storage device 3 in this write mode
Data corresponding to the cursor outputted from the buffer circuit 7 through lines DT ₁ to _{DT 8} is stored in the storage element designated by the signal for selecting the storage element inputted through AC ₁₀ . The data corresponding to this cursor is minute time, and
It is memorized so that cursor display can be executed from _t1 . Note that the data corresponding to this cursor is also stored in the storage device 9.

When the storage of the data corresponding to the cursor in the storage device 3 is completed, the output signal from the arithmetic processing unit 8 causes the CS line output of the buffer circuit 6 to go “H”.
WT line output is set to “H”. With the setting of these two lines to "H", the cursor display starts from time _t1 .

Since the CS line is "H", the selection circuit 2 is switched to connect the output lines AB ₁ to _{AB 10} of the counter 1 and _the lines AC ₁ to AC ₁₀ to the storage device 3. A signal that goes "H" to AB ₁₀ is input from the counter 1 to the storage device 3 via the selection circuit 2. Furthermore, since the WT line is "H", the gate 5 is opened, and the storage device 3 enters a so-called read mode, in which data is sequentially read from the storage element specified by the signal from the counter 1. The signal is output through the shift register 4 and gate 5, and the display shown in FIG. 2B is performed from time _t1 to time _t2 .

Next, data in the memory element in which data corresponding to the cursor in the memory device 3 is stored is rewritten so that the display character "E" is displayed from time _t2 . In the diagram showing the display timing of FIG. 2, this rewriting time is omitted because it is very small compared to the display period.

Now, in order to write the data of the display character "E" into the memory element in which the data corresponding to the cursor is stored, first, the data corresponding to the display character "E" is input using an input device such as a keyboard. A signal for selecting and designating a storage element is output from the processing device 8 to the buffer circuit 6, and the CS line and WT line of the buffer circuit 6 are set to "L".

CS line and WT line are set to “L”,
Storage device 3 set to so-called write mode
_The DT ( _bus ) line,
Data corresponding to the displayed character "E" is written through the buffer circuit 7 and lines DT ₁ to DT ₈ . The data corresponding to this display character "E" is transferred from the arithmetic processing unit 8 to the storage device 9 in the same way as the data corresponding to the cursor.
The data corresponding to the cursor is stored in a different location.

At time _t2 , the CS line and WT line outputs of the buffer circuit 6 are set to "H" by the output signal from the arithmetic processing unit 8. As these two lines are set to "H", data is read out from the storage device 3 based on the signal from the counter 1, and as shown in FIG. 2A, the displayed character "E" is moved from the cursor.
The rewritten version is displayed from time t ₂ to time t ₃ .

Next, from time _t3 until time _t4 , a cursor is displayed in addition to the displayed character "E". At this time, data corresponding to the cursor is read from the storage device 9 and written to the selected storage element in the same manner as the above-described writing of cursor data in the storage device 3. Then, by reading and displaying the data corresponding to the cursor written in this storage device 3, the time is changed from time _t1 to time.
The cursor is displayed in the same way as up to t ₂ .

By repeating such operations, the cursor display method of the present invention becomes possible. At this time, if the cursor is displayed in a color opposite to that of the back, the display becomes easier to see. Further, for example, when the cursor is displayed at the next position to indicate the next display position of "E" in FIG. 2, the cursor itself begins to blink.

According to the present invention, with the configuration as described above, it is possible to provide a display device with a more excellent cursor display function. In addition, in Figure 3, AB line, AC line, AD line
Although we have explained that the lines and DT lines are 10, 10, and 8, respectively, it goes without saying that any number can be selected.

[Brief explanation of drawings]

FIG. 1 is an external view of the display device, FIG. 2 is a diagram for explaining the display method of the present invention, and FIG. 3 is a block diagram of the display device in an embodiment of the present invention. 1... Counter, 2... Selection circuit, 3, 9...
Memory device, 4...Shift register, 5...Gate, 6, 7...Buffer circuit, 8... Arithmetic processing unit, 10... Timing circuit.

Claims (1)

[Claims] 1. Displaying a cursor to indicate the next display position and the characters, numbers, symbols, etc. at the display position alternately on a display element such as a CRT that displays letters, numbers, symbols, etc., and displaying the cursor. A display device configured to display the characters, numbers, symbols, etc. over a display period T ₂ that is longer than the period T ₁ , the display device having a display device for storing the characters, numbers, symbols, etc. as well as data signals for displaying the cursor. During the display period _T1 , a data signal for the cursor display is written and read in a memory device configured with a memory element corresponding one-to-one to the display position of the display element, and a memory element corresponding to the cursor display device; During the display period _T2 , the display device includes a control means for writing and reading data signals for displaying the characters, numbers, symbols, etc.