JPS58128073A - Electronic counter - Google Patents

Abstract

PURPOSE:To reset the display of a counter to ''0'' automatically, by providing a tape end detection circuit in which an output signal level is changed in detecting the tape end, and a means outputting a pulse with the change of the said signal level. CONSTITUTION:When the tape comes to its end at a time t1 and the rotation of a reel stand is stopped, since a pulse signal from a pulse generating circuit 101 is stopped, a capacitor 502 is not charged and not discharged at a resistor 502 immediately but gradually. Thus, the potential of the capacitor 502 is lowered gradually. When this potential is decreased to a value, the 1st one shot multivibrator circuit 504 is triggered to output a pulse having a prescribed pulse width. This pulse is inputted to the 2nd one shot mulivibrator 505. The 2nd one shot multivibrator 505 is triggered at the trailing of the pulse and outputs a signal of ''L'' level for a prescribed period. Thus, when the tape end is detected, the display of the counter is reset to ''0'' automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic counter circuit for displaying the number of revolutions of a reel stand of a magnetic recording/reproducing device such as a tape recorder.
This is an improved K counter reset and relates to a nine-electron kakunta.

Figure 1Ii1 shows an example of a conventional electronic counter that counts and displays the number of rotations of a reel stand of a tape recorder.The pulse generation circuit 101 that outputs a pulse signal in proportion to the rotation of the reel stand is a multi-ND circuit 301°. One input terminal KI! of each of 302! It's been tied up. On the other hand, the unwinding (hereinafter referred to as RmW) output of the mechanism control tc102 (for example, Rm12001) is output from the inverter 305.
The other input terminal KII of the MMD circuit 301 is connected to the other input terminal KII of the MMD circuit 301, and the output of the MMD circuit 301 is connected to the other input terminal of the AND circuit 302. Also, for the up (σP) input of
The output of the MMD circuit 302 is also connected to the DOWN, Q)ON) input. The carry (0m RRY) output of the up/down counter 203 is input to the up input of the next digit up/down counter 213, and the borrow (BOXROW) output of the up/down counter 203 is input to the down input of the up/down counter 213. The up/down counters 203, 213, etc. constitute a multi-digit counter. Up/down counter 2
The count output of 03゜213... (hereinafter omitted) is connected to the decoder driver 202, 212... (hereinafter omitted), and further one decoder driver 202, 21.
The output of 2 is connected to the Dament display 201, 211 and 7-.
・・・・・・(The following is omitted) Kl! It is continued. Further, a reset switch 401 is connected to the reset terminals of the up/down counters 205 and 213.

Now, in the conventional apparatus configured as described above, when the mechanism (not shown) of the tape recorder is RIW, the mechanism control 1102 outputs the RMW signal. This rounding pulse signal outputted from the pulse generation circuit 101 and proportional to the rotation of the reel stand is
It is input to the down terminal of the up/down counter 205 via the D@ path 302. Then, when a borrow occurs in the up/down counter 203, the borrow output is input to the next digit's 7//Kunka Kunta terminal 213, so the count representing the number of rotations of the reel stand is Next is subtracted.

7 On the other hand, the mechanism! At times other than tllY, the RIW output of the mechanism control 1o102 is at the IIJ'' level and is inverted by the inverter 505. Therefore, the output of the pulse generation circuit 101 is It is input to the up terminal of Kun★Kunta 205. A carry occurs in the up/down counter 203, and 9 and self are input to the up/down counter 215 of the next digit.
Since it is input to the up terminal of , the count number is successively added.

When the reset switch 401 is turned on, the count is reset regardless of the up/down input.

Up/Daufukakun! 203, 213----0 count number output is decoder//driver 202゜212・
..., and here it is converted into 7-segment display data. 7 segments) 0 display 201.21
1... is the decoder//driver 202゜212,
. . , each up/down counter 20i3-, . 213...4/) The count number is displayed in numbers.

As described above, in the conventional device, the only means for resetting the counter is the reset switch 401, which has the drawback of requiring the user to take the trouble to reset the counter at the beginning of tape winding. Also, when you get depressed,
There was a drawback that the counter was forgotten to be reset at the beginning of tape winding, and the previous tape was counted and the count started from the nine count value.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of the prior art described above and to provide an electronic counter that automatically resets when the tape end is detected.

In order to achieve this object, the present invention provides a tape end detection circuit whose output signal level changes when detecting the chijien r, and a means for outputting a pulse according to a change in the scissors signal level, and uses the scissors pulse signal to control the counter. There is a problem with the way I reset it.

Hereinafter, the present invention will be explained by examples. FIG. 2 shows an embodiment of the present invention; in III, 50° is a chijien y detection circuit, S04 is a first one-shot multi-circuit, 505 is a second one-shot multi-circuit, 501.
SO5, 605 and 405 are resistors, 502 is condenser f-1401 is operating butane (e.g. PLAY, FF
, ItlW, etc.), 402 is MA) TD circuit, 604
, 406 indicates 5yyzp, and other symbols indicate the same or equivalent components as in FIG. There is.

Also, number 2! ID signals a, b, o, fL (
The D waveform is shown in FIG.

Now, in an electronic counter having such a configuration, a pulse signal proportional to the rotation of the reel table is outputted from the pulse generating circuit 101 when the tape is traveling. Smoothed with Conden+502. Also, at this time, the output of the NDiil path 602 is at the 'L' level as shown in Fig. 3 (←). Therefore, the potential at the connection point between the resistor 501 and the capacitor 502 is as shown in Fig. 3 (
As in a), maintain the 1H1 level state.

Next, at time tIK tape end, when the reel stand stops rotating, the pulse signal from the pulse generating circuit 101 also stops, so the capacitor 502 is not charged and continues to be discharged by the resistor 503.

As a result, the potential of the capacitor 502 increases as shown in FIG.
As in, it gradually declines. When this potential drops to a certain value Kt, the first one-seat multi-layer Bl&504 is triggered and outputs a pulse with a predetermined pulse width. This pulse is input to the second one-shot multi 505. The 1s2 Sod Multi 505 is triggered by the falling edge of the pulse, and as shown in FIG. 3(0)K,
A signal a1 at the ILI level is output for a certain period of time. This signal CI is hot down kakunta 205, 213.・・・・・・
... is input to the reset terminal.

Therefore, when the tape end is detected, the counter display is automatically reset to eQac.

In addition, when these operations are stopped during play or rewinding, etc., the displays 201, 211, . . .
The display of ... must retain the value at the time the operation was stopped.F! Of course. A book for when you stop this operation midway! J! The operation of the embodiment will be briefly explained using FIG. 4. Fourth
The figure is a of FIG. 2, similar to 511.

The waveforms of t+, o, and l are shown.

Now, suppose that the city f is running due to the playback, etc., and while it is running, there are 0 paths forward, and the potential at the connection point between the resistor 501 and the capacitor 502 is K as shown in Fig. 4 ←) When the stop button is pressed on one of the operating buttons 102 at time 0 while the IHs level state is maintained, the pulse signal at the 1110 level is output to the 1110 level pulse. The stopper used is one that returns to its original state immediately after being pressed and turned on.

Now, when IHl level AO Hals 4 is output from the HA)II) circuit 602, the transistors 604 and 60
6 is conductive, and the signal a#i"L" repeats AKIII,
The signal is forced to the KII, # level.

The first one-shot multi-circuit 504 is triggered by the fall of this signal a! The pulse width is selected to be sufficiently short compared to the pulse @ to the above-mentioned pulse. This rounding,
Signal 1 is unaffected by the pulse output from the first one-shot multi-circuit 504, and signal I7. Maintains I level status. Therefore, the second one-shot multi-circuit 505 has a tri! No input is received and the state is maintained at the '51 level. As a result, up/down counters 203, 213 . ... will never be reset.

As described above, according to the vAIIc of the present invention, when Chijien r is detected, the counter display is automatically reset to IO-, so the user does not have to take the trouble to press the button to set the counter display to 101. This has the advantage of eliminating the hassle of having to reset.

[Brief explanation of the drawing]

Figure j11 is a conventional electronic counter circuit O block diagram, the second
The figure shows a Zorrock diagram of an electronic counter opening according to an embodiment of the present invention, and FIGS. 3 and 4 show waveform diagrams of signals of the main parts of FIG. 2, respectively. 101---ylhx '1 circuit, 203.21s・-
7 tsuzo/down counter, 5OO-... tape end detection circuit, 504... first one-shot multi-circuit,
505--Second one-shot multi-circuit, 601-
・・Operation button agent Patent attorney Michi Hiraki Talent 1 figure skill 2 figure

Claims (1)

[Claims] (11) In an electronic counter IIc having means for generating a pulse signal proportional to the rotation of the reel stand of the magnetic recording/reproducing device, means for counting cough pulse signals, and means for displaying the number of counts, the reel is reeled at the end of the tape. comprising a scissor end detection means for detecting that the rotation of the table has stopped, and a means for outputting a pulse when a chisel end y is detected by the means, and the scissors pulse output is connected to a reset circuit of the counting means. 4. Accordingly, the counting means is automatically reset at the first step. Electronic counter with mold.