JPS6411970B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a display device, and in particular, an input field clearing operation that was conventionally performed by operating an "ERASE EOF" key and specifying a cursor can also be performed by operating a light pen. The present invention relates to a display device.

As input/output terminals for data processing systems, display devices are used in a variety of fields because they are particularly suited to interactive forms of processing. When an operator wants to input data on a display device, he or she generally inputs the data by operating a keyboard attached to the display device, and then displays the input data on the display screen. Therefore, the input data is checked. By the way, when inputting data while displaying data on the screen in this way, there may be cases where the user notices an operational error midway through and wants to clear the input data after a certain portion. In such cases, the conventional method is to move the cursor to the beginning of the part you want to delete, and then
By operating the "ERASE EOF" key, the input field after the cursor position was cleared.

Figure 1 is a diagram showing an example of the operation of the "ERASE EOF" key. In the figure, 1 is the display screen before the "ERASE EOF" key is operated, and 1' is the
2 is the "ERASE EOF" key, 3 is the displayed character, 4 is the attribute character position, and 5 is the cursor. In the figure, the attribute character positions indicated by broken lines are not displayed on the screen and are not printed. This attribute character is defined by a control code that controls a data field, which is the smallest unit for performing logical processing, display, printing, etc. of data. The data field controlled by one attribute character is from the attribute character position to immediately before the next attribute character. In the diagram, attribute character position 4
Data fields marked with a "P" are protected fields and cannot be input from a terminal, and data fields marked with a "U" are unprotected fields (input fields) and cannot be entered from a terminal. This is an input-enabled field.

In FIG. 1, in the input field of screen 1,
If you want to delete the displayed portion of "777-1111", first move the cursor 5 to the position shown (the beginning position of the portion to be deleted). And after that,
Operate the "ERASE EOF" key. By this operation, the portion of the input field after the cursor position is deleted as shown in screen 1'.

In the input field clearing process as described above, the cursor must always be moved to the beginning position of the part to be deleted. Therefore, if the cursor is located far away, the input There was an inconvenience that the field clearing process was time consuming.

The purpose of the present invention is to solve the above-mentioned problems and to make it possible to easily perform the same processing as the input field clearing process using the conventional "ERASE EOF" key operation using only a light pen operation. A display device according to the invention includes a position detecting means for detecting a position on a screen specified by a light pen, a field attribute detecting means for detecting an attribute of a field including the specified position, and a field attribute detecting means for detecting an attribute of a field including the specified position. If the field is an unprotected field, the input on the screen specified by the above light pen shall be provided with field clearing means for clearing all characters at the position specified by the above light pen and thereafter up to the end of the field; It is characterized by performing a field clearing operation.

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 2 is a block diagram of essential parts of a display device according to an embodiment of the present invention, in which 10 is a display screen, 11 is a light pen, and 12 is an ERASE screen.
EOF input detection section, 13 is normal input detection section, 14
15 is a position determination section, 15 is a cursor position specification section, and 16 is a position determination section.
17 is an attribute character reading unit, 18 is an attribute character determining unit, 19 is an erasure processing unit, 20 is a buffer memory, 21 is an AND circuit, and 22 is an OR circuit.

In the illustrated embodiment, the light pen 11 has two pick-up parts, one of which is used to perform the same light pen function as the conventional one, and the other (shown in black in the figure). part)
is the pick-up section used for the present invention.

In addition, in the embodiment, the display screen 10
has a capacity of 24 rows x 80 columns, and accordingly, the buffer memory 20 has a capacity of 24 x 80 = 1920 bytes. When a code such as alphanumeric characters, kana characters, or kanji characters is set in the buffer memory 20, the corresponding alphanumeric characters, kana characters, kanji characters, etc. are displayed on the screen accordingly. Note that each alphanumeric character and kana character is represented by one byte, and each kanji character is represented by two bytes.

Next, the input field clear processing operation in the embodiment will be explained below. Display screen 1
If you want to erase a certain input field among the characters displayed above 0, bring the pick-up part of the black part of the light pen 11 close to the beginning position of the part you want to erase. As a result, the pick-up signal from the pick-up section is detected by the ERASE EOF input detection section 12 and sent to the position determination section 14. The position detecting section 14 detects the coordinate position on the display screen 10, and sends the coordinate position information to the attribute character reading section 17 in the form of buffer memory address information. The attribute character reading unit 17 holds the buffer memory address information sent from the position detection unit 14 in an internal register A (not shown), and sets the value of the internal register A to a buffer memory access address register B (not shown). Then, reading from the buffer memory 20 is started. The read operation is performed by subtracting the contents of the buffer memory access address register B by -1,
These operations are performed sequentially until the attribute character defining the input field is read. Then, when the attribute character that defines the input field is read out, this attribute character is sent to the attribute character determining section 18. The attribute character determination unit 18 examines the specific bit position in the read attribute character and determines whether the data field is a protected field or an unprotected field (input field). Then, when the data field is an input field, the attribute character determination unit 18 activates the erasure processing unit 19. The activated erase processing unit 19 sets the value of the internal register A described above to the buffer memory access address register B also described above, and starts accessing the buffer memory. For access from the erase processing unit 19, first, data is read from the buffer memory 20 based on the contents of the buffer memory access address register B, and if the read byte is not an attribute character, the byte is changed to a NUL code and written. The access is performed in such a manner that the contents of the buffer memory access address register B are incremented by +1 each time one byte is processed.

In this way, when all parts of the input field after the part specified with the light pen are cleared and the attribute character at the beginning position of the next field is read, the erasing processing unit 19 ends the process and displays the data as shown in the figure. Reset each part using the correct route.
In addition, in this embodiment, the input field can be cleared by the cursor operation and the "ERASE EOF" key operation as before, and when the ERASE EOF key is operated, the EOF key operation detection section 16 opens the AND circuit 21 and sends the cursor position information from the cursor position determining section 15 to the attribute character reading section 1 through the OR circuit 22.
7, and the input field is cleared in the same manner as described above. It goes without saying that when the pick-up section of the light pen 11 on the side opposite to the black portion shown in the figure is used, the normal input detection section 13 operates and normal light pen operation is performed.

In the embodiment shown in FIG. 2, the light pen is provided with two pick-up parts, but only a single pick-up part is provided, and the pick-up part is controlled by a push button mechanism etc. added to the light pen. It is also possible to switch the output to either of the input detection units 12 and 13 and send it out.

As explained above, according to the present invention, the input field clearing process can be completed using only the light pen, which has the excellent effect of simplifying the operation for the operator and shortening the operation time. can bring.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the operation of the "ERASE EOF" key, and FIG. 2 is a block diagram of a main part of a display device according to an embodiment of the present invention. In Figure 2, 10 is a display screen, 1
1 is a light pen, 14 is a position determination section, 17 is an attribute character reading section, 18 is an attribute character determination section, 19 is an erasure processing section, and 20 is a buffer memory.

Claims (1)

[Claims] 1. In a display device equipped with a light pen, the light pen is capable of outputting a pick-up signal for erasing a field on the screen, and also outputs a pick-up signal to erase a field on the screen specified by the light pen. A position detecting means for detecting with a signal, an attribute detecting means for detecting the attribute of the field including this position, and a field erasing means for erasing all characters in this field if the attribute of this field is an unprotected field. and means for erasing unprotected fields on the screen with a light pen.