JPS5948170A - Electronic typewriter with automatic correcting function - Google Patents

Abstract

PURPOSE:To raise the operabilty of back spacing when automatic correction is made by using a system in which when back spacing action is made beyond memory region, the condition is notified to an operator. CONSTITUTION:When back spacing of line is made during the correction period, automatic correction is made up to the limiting three lines where no error of deviation of line position occurs. A back space key is operated and a carriage is moved. When the position of letters not stored in a compilation buffer 40 is reached beyond three lines. The alarm generation circuit of an alarm control circuit 39 is driven, a buzzer sound is generated for a fixed period of time, and the condition is notified to an operator to stop or control the movement of the carriage. When old print letters are corrected beyond the position, manual correction is made by operating a manual correction key.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Application in Industry I> The present invention is used in an electronic typewriter that prints based on electronic control by operating character keys. In particular, this type of typewriter is equipped with an automatic correction function that includes a buffer memory (-time storage device) for the input sentence so that if the typist makes a mistake in typing, the error can be corrected by simply pressing the +1 key again. This relates to electronic type-likes.

<Prior Art> An electric typewriter was proposed in Japanese Patent Publication No. 56-8388. An electronic typewriter equipped with an automatic correction function has also been proposed in Japanese Patent Laid-Open No. 49-44808.

This automatic 31 city function stores the number of input characters for about one line in the buffer memory, and stores this stored %mlK (
In the range of J' minutes, select the erroneous character by operating the erase key at the corrected recording character position 2, and press the eraser again using the erase ribbon to erase the erroneous printing, and then When a correct character is manually input on a key, a valid character is printed at that position, and a valid character is also manually input at the corresponding position in the buffer memory.

However, in the conventional automatic correction function, 1. As shown, the number of characters for one line is stored, and automatic correction 1E can only be performed within this range, which limits the correction function. In other words, the current situation is that automatic correction cannot be performed beyond the range of one line, and this automatic correction function is not fully utilized. In addition, when the printing section (printing section) and space operation is performed during this correction, if the memory area for one line is exceeded, there is no instruction in r1, and the operator is in such a state. There were many erroneous operations such as performing Kazuko's corrective actions.

<Objective of the Invention> The present invention has been made to improve the problems of the automatic correction II function as described above, and to provide an electric typewriter with excellent operability for the operator. In particular, when a bank space operation is performed beyond a memory area, the state is made known to an operator of some means.

<Example> Figure 1 shows the appearance of the electronic typewriter of the present invention.
The keyhole 11 includes a keyboard 1 and a printing section 2.
The section has a group of alphabet keys, space keys (hereinafter referred to as character keys) 11, and a group of various control keys 10.

The printing unit 2 may be of a type generally known as a DZ wheel printer (equipped with a petal-shaped type wheel), and has a mechanism known, for example, in the above-mentioned Japanese Patent Publication No. 56-8388.

22 is a platen, and the platen 22 functions to move the recording paper in the vertical direction by means of a knob 23 or a paper feeding mechanism.

A carriage 21 includes a type wheel, an ink ribbon, and an erasing ribbon, and is moved forward or backward by a stepping mechanism.

This erasing ribbon is placed on the printing surface in place of the ink ribbon by correction control, and at this time, the erroneously recorded characters are erased by printing desired characters (erroneously recorded characters). 17 is a display device.

Next, the correction function operation will be explained. Characters input using the character keys 11 of the keyboard are printed on recording paper with an ink ribbon, and the character information is stored in an internal storage device (editing buffer).

This editing buffer has a storage capacity of, for example, 200 characters, and when input exceeding this capacity, the oldest character information is shifted in order and taken out from the buffer and erased.

When correcting characters that have already been printed, character information corresponding to the character at the position placed by the carriage is read out and printed via the erasing ribbon. By doing this, the ink that has adhered to the recording paper is removed by printing JjSS"tr, which has the same shape as the print pattern, through the erasing ribbon. In addition, the white paint, etc. In this way, the correction i1E function is automatically executed.

However, this correction function cannot be achieved unless character information is stored in the buffer.

In other words, the old input character is shifted out of the buffer to correct the erased character.

In this case, manual correction is performed by manually inputting the characters corresponding to the 11th grade. This is because if the capacity of the buffer is increased, there is no problem with the troublesome operation of manual correction, but mechanically it is not possible to increase the capacity of this buffer infinitely.

One reason for this is that the horizontal movement of the carriage is swept by a wire driven by a motor, which allows for highly accurate position control, but for the vertical direction, that is, controlling paper feed by rotating the platen, a coupling mechanism such as a gear is used. In addition, a slight error in the amount of movement may occur due to slipping between the platen and the paper, and if the paper is fed many times, the error will accumulate and cause a shift between the already printed position and the erased print when correcting. This is because errors may occur and cannot be corrected.

Another problem is that even if this error could be overcome, it would be expensive.

Therefore, in this example, the above-mentioned movement amount error does not occur and the functionality of automatic correction can be maximized. Specifically, this automatic correction is performed within a range of 200 characters or 3 lines. This is what made it possible.

Next, the control key group 10 will be explained.

-, t--12 is a backspace key, and each time this key is operated, the carriage is moved back by one character.

The EXP key (ExPRESS) 13 is a key for moving the gear ridge to the position of the first character stored in the buffer 7.

RE L key<RELOCATE)+4 is a key to move the carriage to the current input position.

MC key (MANUAL C0RRECTION) +
5 is a mode key for setting the manual correction mode in the writing analysis function.

C key (CORRECTION) + 6 is a correction key, and printed characters are erased by operating this key.

FIG. 2 is a block diagram of the present device, and this diagram will be explained.

30 is the aforementioned keyboard device, which supplies key signals from this device to the encoding circuit 31. This encoding circuit 3
1 generates a coded signal (character code, control code) corresponding to the key. These -1-F signals are supplied to the editing control circuit 32.

The editing control circuit 32 is connected to a RAM 34 via a data bus.
, a ROM 36, a print control unit 33, a display, and a notification control section 39 having a notification sound generation circuit.

ROM 36 nict Edit control program 42, a step amount table 43 that stores the amount of step of the carriage corresponding to each character, and a paper feed (1 tj) that determines the amount of rotation of the platen.
- Store the pull 44. This editing control program 42
are not shown in FIGS. 3 to 7.": A control program is stored.

The ROM 84 includes an edit buffer 40 and address pointers AP, ~AP5 (41) that store address values for each state.
and each status flag F] + F 2 + F 3 +
F4 and non-counter K are provided.

The pointer API stores the address of the start position of the edit buffer 40, the pointer AP2 stores the address of the end of the first line, the pointer 8P3 stores the address of the end of the second line, and the pointer A I'4 stores the address of the end of the second line. The address of the manual position is stored, and the pointer AP5 stores the address corresponding to the carriage position during backspace during correction iE.

Reference numeral 38 designates the printing section 2 of FIG. 1 in block form. These are generally known mechanisms.

The niJ printing section 38 includes a type selection mechanism 50 for rotating and arranging a desired type on a type wheel connected to a motor or the like to a printing position, and a type selection mechanism 50 for rotating and arranging desired type at a printing position using a solenoid or the like to strike the ``2'' wheel to select an ink ribbon or the like. A mechanism 51 for impacting the platen through the erasing ribbon; and an ink ribbon mechanism 52 for placing the ink ribbon at the printing position in synchronization with J. (This operation is prohibited), I; mark (selected when operating the Yogini 16, and a fire extinguishing ribbon mechanism 53 for arranging the fire extinguishing ribbon to the printing position in synchronization with printing, and a carriage moving along the platen according to the characters. A mechanism 54 that moves a predetermined moving tank (step amount) in the forward or backward direction (moves within the left and right margins), and a mechanism 54 that moves the recording paper 1-up (forward) or -down (backward). The apparatus includes at least a mechanism 55 for rotating the platen and a sensor mechanism 56 for detecting the position of the carriage.

On the other hand, FIG. 8 shows an example of the character information stored in the editing buffer 40, and FIG. 9 shows the printing state.

Next, the operation of the device described in item 1 will be explained by function.

(1) Character manual (printing) operation (see the flowchart in Figure 3) At this initial stage, the address pointer AP ~ AP5 is located at the beginning (1? position) of the editing buffer 40, and as shown in Figure 8. An example is shown in which the indicated characters are manually generated.

First, when a character key is operated (in this example "S"), if it is not a new line key, the address value of AP4 or the address circuit (
ADRA) 35, and the character code is stored at the beginning of the editing buffer 40. Furthermore, the type selection mechanism 50 of the ``U'' printing section. Hammer mechanism 51. Ink ribbon mechanism 52
Drive and print. (Step 10 of the flow in Figure 3)
0~10/I) When the above printing is completed, the above characters ('8''
) is stored in the step amount table 43 of the ROM 36.
Then, the I-recorded carriage step I-fτ machine t1η54 is driven to move the carriage forward (step 105).

Next, AP4”-! Also, AP this content.

Transfer to. At this time, the gear ridge moves to the next printing position.
I'm here. Therefore, AP4. AP5 is an address value indicating the position 92 in FIG. Further AI' 41j: n
It is determined whether the address corresponds to (200 gearactors) or the cup (steps 107 and 108).

In this way, each time a character key is input, it is sequentially stored in the buffer 40 and printed.

In this way, if you input characters sequentially up to position 93 in Figure 8 and press the line feed key here, the flow will proceed from step 101 to 110. and AP as explained above.
The address value of 4 is transferred to the ADRA circuit 35, and the line feed code is stored in the buffer 40. Furthermore, the platen mechanism 55 is driven according to the paper feed meter table 4/l in the ROM 36 to move the recording paper one line in the forward direction (step 112).
).

Since flag F1 is now in its initial state and has been reset, the process proceeds to step 114 and increments counter () by 1 (K=I).Furthermore, it is checked whether it is equal to 3, that is, whether it has exceeded 3 lines. A determination is made (steps 114, 115).

History: Transfer the address value of AP3 to AP2 (step +16). In this case, the values of AP3 and AP2 are both v
It is in the position 91 in Figure 8, and does not actually change.

Then, AP4 is transferred to AP3. Diameter is AI)
3 stores the address value of the first row (A) in FIG.

Furthermore, AP4 is incremented by +, and this value of AP4 is transferred to AP5 (steps 118 and 119). For this reason, AP4. Al15 indicates the position of σ)95 in Fig. 8.

By repeating the operation 1- above, when AP is at 99 in Fig. 8, A I' 31.1B〒-jo) end of line (
97 in Figure 8), AP2 is the end of line A (94 in Figure 8)
, A p l do not show 91 in FIG. 8, respectively.

Now, if the character power reaches n (200 characters), the process proceeds to step I08, J:120, and the buffer 4o is shifted to the left by one gear (step +
20). Therefore, the character "S" at the beginning of the buffer 40 (91 in FIG. 8) is pushed out and erased.

Then, AP2 to AI)5 are reduced by one character. In other words, AP 3 is 96 in Figure 8, AP2 is 93-
, AP 4 , AP s will not show 98.

Also, in Figure 8, the human power in the third row is not completed, but the
When the line feed key is operated following the human input character "'4" in the figure, =3 is detected at step +15 marked 11,
Step 1. '(Proceed to 0.

When proceeding to this step 130, the flag I? , and performs steps 131 onwards to erase the first line (line A) from the buffer 40. As explained earlier, if a large number of rows are stored in the row direction, line misalignment will occur when returning the rows during correction, so there is a limit to the number of rows that will not cause this error. This is because it exceeds the length of three lines.

To explain the operation after step 131, Δ■)2 is increased by one character. Then AP2 is at the beginning of line B
5. Furthermore, AP from the position indicated by AP2
Transfer character information to the location shown in . Therefore, the character "X" in FIG. 8 is stored in 91. Then, AI'2=A
It is determined whether it is I'3, and AP, . . . /M'2 is further increased by +. Do not repeat this operation until 1'2=AI)3.

Therefore, characters 95 to 97 in FIG. 8 will be stored in order starting from position 91.

Furthermore, it is operated after step 140, and I
The character group ``+21314-1'' is transferred to the position following ``XYZ.-1'' (steps 140-144).

Then, when AP3=AP4, steps 145 to 147
is operated, and this causes A P , or position 91 in Figure 8, AP2 is at the end of line B, and AI) 3 is at line C? J″ end position, AP4 and AP5 respectively indicate the start position of the 19th line.

By repeating this operation, the buffer 4 is
The first row stored as 0 is deleted. Thereafter, the process advances from step +13 to step 131.

To summarize, if the number of characters exceeds 200, the first character information (81'A91) will be deleted when characters are input, and if the number of characters exceeds three lines, the first line will be deleted. Therefore, the 400 angstrom character information of the bara is not more than 200 characters. -r is never exceeded. Note that these 200 characters correspond to about 3 lines (A4-size) when the characters with the least number of steppers are continuously written manually.

(11) Bank space key (・- key) operation (refer to the flowchart in Figure 4) When entering characters 7TJ' +l:, operate this bank space key to move the carriage to the desired position. .

In F11- of FIG. 4, when the bank space key is operated, F2 is reset (if the MC key is not operated, it is reset), so step 202 is executed.
Then, AP5=AP□ is compared with Φ.

Now, hypothetically, AI'5. Assuming that AP4 is fully shown in FIG. 8, that is, the carriage is located in the C line character is' device (next print character I\'r, position). Therefore, the process moves to step 203.

This step 203 is AP5 or galactor 1
In response, AP5 shows the full view of FIG. 899. Then AP
5. =AP3, AP5-AI] It is judged whether Article 2 fl is satisfied or not. Here, the process moves to step 206, so that the address value of A P 5 is supplied to the ADRA circuit 35, and the character "4" of the space ζJl+i> is read out.

Furthermore, the step number corresponding to this character is read out from the M2C step table 43 and supplied to the carriage step mechanism 54 of the printing section. The carriage is moved back by this increment digit. Therefore, the gear ridge is placed Mt at the character position "4"' on the C line (steps 203 to 208).

Every time the backspace key is operated in this way,
- The operation described in item 1 is repeated.

If this backspace key is operated when Carry, Di or C is positioned at the beginning of line C, AP5 is set to 1 in step 203.
is reduced by the character (shown at position 97 in Figure 8),
At this time, the condition AP,=AI': is satisfied, and the process moves to step 220.

In this case, the rotation amount of the re-platen is read from the paper feed table 44 in the ROM 360, and is supplied to the platen mechanism 55, and the platen is rotated in the opposite direction of ji+- corresponding to one line (recording paper backward), and the gear ridge is moved to the B line. This will indicate the beginning of.

Furthermore, the address value increased by one character (position 95 in FIG. 8) to AP2 (shown at position 94 in FIG. 8) is transferred to AP5, and the operation described in [. is repeated.

The address value of Zunawaji AI) 5 is supplied to the AI) RA circuit 35, the corresponding character is read out from the editing buffer 40, the step amount is read out from the step amount table 43, and it is applied to the carriage step mechanism 54. to move the carriage forward (
Steps 221-225).

Next, add one character to AP5, AP, = (
AI) Repeat the operations described in -4- until 3-1).

When the gear ridge reaches the position of the letter "Z" at the end of line B (FIG. 8, 96), the gear ridge stops.

Further, the condition 8P5=AP3 in step 222 is for stopping at the beginning of line B when there are only line feed codes in line B. Also, if this hackspace operation is operated when the gear ridge is located at the beginning of BAT', steps 230 to 237 will be executed in the same way as the above operation. executed.

With the above operation, 1 is created by operating the bank space key.
When the carriage passes through one line, the carriage is moved to the end of the 1111th column line, and as a result, the carriage is sequentially moved in the opposite direction of character input.

Gear Ridge also edits the top of the sofa 40 (Fig. 8 91)
If you operate the hack space key when the character is in the buffer, the character position will be a character position that is not stored in this buffer.
Then, the process moves to 209 and the notification of the notification control circuit 39? 1 generation circuit is driven, generates a buzzer 1' for a predetermined time,
Notify the operator of this condition. Further, at this time, the movement of the carriage is controlled to stop by moving to step 209 in [)1j. Therefore, the operator can know that a hack space operation has been performed beyond the area of the buffer 40, either when the single carriage stops or when the buzzer sounds.

If old printed characters (characters erased from the buffer) are to be corrected beyond this position, it is necessary to manually correct them by operating the MC Yagi-5.

Note that an indicator lamp may be turned on by the circuit 39 instead of the buzzer.

(III) Automatic correction operation (see flowchart 1v in Fig. 5 (b)) In this case, when the correction key +6 (hereinafter referred to as correction key) is operated, the erasing ribbon mechanism 53 of the print section is selected. A ribbon is placed at a printing position (step 401).

Assume now that the carriage is located at the "Z" position of line B (FIG. 8, 96, L AP5 = AP).

Since it is not, the process moves to step 404. For example, AP5
=AI'l, the notification control circuit 39
is driven.

1) In 1j entry Otsu, n, \p 404, one character is decreased from A P 5, and this address value is AI) R
Supplied to A circuit 35, from buffer 4o = 11 knots:
The character code ('Y'' character in FIG. 8) is read out (steps 402-406).

If this is not a line feed code, the step h1 is read from the step amount table 43 in the ROM 36, and the gear ridge is moved backward. Historically, type selection mechanism 50° hammer mechanism 51. The corresponding character (Y'') is printed by the erasing ribbon mechanism 53 via the erasing ribbon.

Therefore, the corresponding characters are removed from the recording paper (steps 408-409). Character “Y” in buffer 40
” is deleted and the position becomes blank (step 4).
1o). Also, the erasing ribbon mechanism 53 is released.

At this time, the 1st gear ridge is located at the erasing character (l'/).1 Although not shown in the figure, if you manually input a common character, this character will be printed and the character will be written and played in the buffer, and the gear ridge will be set to Z. :f ha, is advanced in steps.

Each time you operate the above-mentioned heavy/heavy keys, 1. The operations described above are executed.

When the line feed code is read out, the process moves from step 407 to 412, where F3 is set and the process moves to step 202 in FIG. 4, where the same operation as the bank space operation described above is performed. That is, the gear ridge moves to the end of the previous stage, and the process further moves to step 239.

In step 239, F3 is reset and AP5 is set to A.
DR is supplied to 35 for 8 times, reads the character code corresponding to 7J from the buffer, and if cJ is not a line feed code, it returns to Figure 5 (0
) Returning to step 409, the corresponding characters are printed and erased via the erasing ribbon in the same way as the previous operation.

Also, when the line feed code is read in steps 241 and 242 in FIG. 4, the process proceeds directly to step 41 in FIG.
1 and the erase ribbon is released. In other words, only the erase ribbon is released without extinguishing the character whose line feed code is read. When the gear ridge moves to the top of the automatic heavy/heavy area, a notification is generated and the operator then confirms that manual correction 1 [(S) is not correct and operates the MC key 15.

When you operate this MC key (step 3 in Figure 5 (a)
00)・F2 is set, the notification control circuit 39 is driven, and “MANUAL C0RRE” is displayed on the display 17 in FIG.
The character position “CTION” is lit (step 301
, 302).

The operator will then move the carriage to the desired position by operating the bank space key again.

When this backspace key is operated, since F2 is currently set, the process moves from step 20+ to 210 in FIG. 4, and the process is moved back by one galaxies. The step amount at this time is a step amount on a constant basis (preferably the smallest step amount).

Further, when the carriage is notified of the home position (left margin) by the sensor mechanism 56, it will not move backward by one point. Therefore, the paper feed is not reversed.

From this point on, the operator will proceed as follows: 1. If you want to return it, you will have to manually return it using the platen nozzle 23.

When you position the carriage at the desired position in this way and operate the heavy/high key, the erase ribbon is selected 4 times (5th stroke).
Step 400 in Figure (B)).

Since F2 is currently set, the process moves to step 420. When the operator looks at the characters printed on the recording paper and inputs the corresponding characters, the characters are printed and erased via the erasing ribbon. At this time, the carriage does not move forward.

(V) [1+Dynamic J pressure Carriage automatic movement function in JIE area (1) Automatic movement gear ridge to the beginning of automatic heavy area is automatically gJ' +lE area (buffer character is 111,
F when in the position corresponding to ζ1 area)
When the XI'Goat-3 is operated, the operation flow shown in FIG. 6 is executed.

Then, F2 is reset and it is determined whether AP5=API, and the operation F is repeated until the kneading matches.

It first decrements AP5 by one galactor and supplies that value to the AI)RA circuit 35 to read out the character code corresponding to 71. The step amount corresponding to the letter hood is ROM36
is read out from the step amount table 43, and the carriage is moved backward.

When the line feed code is read out, F4 is set and the process moves to step 204 in FIG. 4 when the backspace key was operated, the carriage is moved to the end of the line in the previous stage f1, and F4 is reset again in steps 243 and 244. Then, the process returns to FIG. 6 and the above operations are repeated.

Then, when AP5=AP, the operation ends r. At this time, the carriage is automatically adjusted to the start '\ position f of the area.

By this, that is, by the carriage moving backward by 111 degrees, the operator can confirm whether the character to be corrected is in the automatic correction area or not.

Furthermore, the gear ridge can be moved by manual operation,
Furthermore, from automatic correction mode to manual correction mode −, [, 1
, by switching the gear ridge to the equipment/device outside the automatic correction area.
＼After moving, manually position this carriage to the beginning of the automatic correction area, and use the E
After that, you can return to the automatic correction mode again.

(2) Moving the automatic correction area to the manual position When the gear ridge is located in the automatic correction area and the gear ridge is automatically positioned to the manual position in the area, RE L
When the OC key 14 is operated, the operation flow shown in FIG. 7 is executed, F2 is first reset, and the process proceeds to step 602.

The operation described in F is repeated until Ar1-Ar4 is reached.

It first supplies AP5 to the ADRA circuit 35 and
1+i>, read the step amount corresponding to this character from the table 43, and move the carriage to this step (
■Run forward. Also, if it is a line feed code, it will be a line feed.

By repeating this operation, the eight-wheel ridge is automatically placed in the next manual position (FIG. 8, 99).

Also, in this position, after changing from automatic correction to manual correction (the carriage is positioned outside the automatic correction area), it is possible to return from manual correction to automatic correction again. In this case, operate the RE L OC key 14 to input an instruction indicating that the gear ridge is located at the position where the manual force is <1'r. When this REIOC key 14 (or the above-mentioned EXP key) is operated, F2 is reset and the display 17 which had been performing manual display is turned off, indicating that it is an automatic 31 city mote.

<Effects of the Invention> As detailed above, in the present invention, in an electronic typewriter equipped with an automatic function, when a space operation is performed beyond the area of the buffer memory,
It is equipped with a means for detecting the condition and automatically notifying the fang pelleter, thereby improving the operability of the backspace operation when automatically correcting.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the external structure of the electronic typewriter of the present invention, and FIG. 2 is a block diagram showing the circuit structure of the device.
Figures 3 to 7 are flowcharts showing the operation flow of the device, Figure 8 is a diagram showing the configuration of the human capacitor, and Figure 9 is a diagram showing an example of recording the characters inputted in Figure 8 by ``s'' and ``1''. be. 1: Keyboard, 2: Print section, 17: Display,
21: Carriage, 22 Nibraten, 30: Keyboard device, 33: Print control unit, 34: RAM
, 36:ROM. 38: Printing section, 39: Notification control 1j4 path, 40: Cottonseed buffer, 41: Pointer, F1 to F4: Flag, K: Counter. ,・5. ... Agent 1'*'=%'',: Yoshihiko Fukushi (and 2 others) Figure 5 Figure 6 '(', 8 [Be1

Claims (1)

[Claims] 1. A printing unit that prints characters on paper by sequentially moving in the horizontal (line) direction in response to character information input from a keyboard;
a memory for sequentially storing a predetermined number of characters in a manually input order of character codes representing character information inputted from the keyboard; revision 1
1 (backspace the printing section in response to an instruction signal, read out the corresponding character code in the memory in the reverse order from the time of storage, select the character of the read character code, and press the erase ribbon) In an electronic typewriter equipped with an automatic correction + IE function consisting of an erasing means for erasing predetermined characters from paper by stamping them through a
a key for giving a backward instruction to the backspace means; a backspace means for sequentially retracting the printing section for each character in response to a signal output by operation of the key; and the backspace means. A memory control circuit that performs synchronization control between the corresponding character in the printing section and the character in the memory written in - in response to the backspace operation; an automatic correction function comprising: a detection means for detecting a state in which the synchronization relationship between the printing unit and the memory is broken; and means for notifying an operator of the state, which operates in response to the detection of the state by the detection means. electronic typewriter. 2. The electronic tie and plater according to claim 1, wherein the means for notifying the operator is a stop means for controlling the movement of the printing section to stop. 3. The electronic typewriter 0 according to claim 1, characterized in that the means for notifying the operator is a notification means such as a display buzzer.