JPS58147877A - Display for remaining amount of vtr tape - Google Patents

Abstract

PURPOSE:To know the remaining amount of a cassette tape easily, by displaying the remaining amount of the cassette tape on the screen of cathode-ray tube of a television receiver druing the operation of a VTR. CONSTITUTION:When the VTR main frame starts recording or reproduction, etc., a remaining-amount display signal generating circuit 14 is driven and on the basis of a horizontal synchronizing signal H and a vertical synchronizing signal V obtained from a television signal receiving and processing circuit 15, a remaining-amount display signal is led out of the circuit 14 intermittently at each prescribed scanning period of the cathode-ray tube 17. This remaining- amount display signal is supplied to the cathode-ray tube 17 through a color signal switching circuit 16 as a substitute for a color signal from said circuit 15 and at the lower part of the screen of the cathode-ray tube 17, nine bars for displaying the remaining amount of the tape at intervals of 15 or 30min and numbers such as 0, 60, and 180 for representing the indication time of the bars are projected simultaneously. The color of the displayed bars is determined by the output information of an AD converter 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape remaining amount display device for a VTR (video tape recorder).

Various new types of devices have been proposed in the past, but if the remaining amount of tape is simply displayed using a counter, there is a risk that the user will not notice the remaining amount of tape and will accidentally record a long program even though there is little tape remaining. there were.

The present invention was made in view of these points, and the present invention has been made in view of the above points.
This invention relates to a remaining amount display device that allows the remaining amount of tape to be easily seen when the tape is in operation.

In particular, the present invention uses the cathode ray tube screen of a television receiver to display the remaining amount of VTR cassette tape when the VTR is in operation.

The present invention will be described below according to embodiments shown in the drawings. 1st
The figure shows a block diagram of a VTR built-in color television receiver implementing the tape remaining amount display device of the present invention, where l is the supply reel inside the VTR main body;
A plurality of, for example, twelve, translucent slits 12.2 are formed on the lower peripheral edge of the reel stand 1, and a light emitting diode 3 and a phototransistor 4 are disposed facing each other with the slit 2 in between. bl. a pulse amplifier that amplifies the rotation detection pulse detected by the five phototransistors 4;
6 is a waveform shaper such as a limiter or a Schmid trigger that shapes the waveform of the pulse signal obtained from the amplifier 5;
7 is a 2H waveform shaped pulse obtained from the waveform shaper 6.
, 6H is a frequency divider that divides the frequency to an appropriate division ratio according to the mode. 8 is a mode changeover switch that is linked to the mode switching of 2H-11-1D [H mode. 9 is a divider that selects the changeover switch 8 from the divider , a triangular wave generator that generates a triangular wave based on the obtained rectangular wave pulse; 10 a peak detector that detects and holds the peak value of the triangular wave signal every time the triangular wave signal is supplied from the triangular wave generator 9; a DC amplifier for amplifying the detection signal of the detector 10; a tape changeover switch 12 for switching the bias of the DC amplifier 11 according to the contents of a 60-minute recording or 120-minute recording cassette loaded in the VTR body; 13 is an AD converter that converts the DC voltage obtained from the DC amplifier 11 into digital information; 14 is a remaining capacity display signal generation circuit that generates a remaining capacity display signal according to the digital information obtained from the converter 13; The circuit 14 is driven only when the VTR main body is in operation. Reference numeral 15 denotes a general television signal reception processing circuit, which receives and processes a television signal received by an antenna or a video signal reproduced by a VTR body. Reference numeral 16 denotes a color signal switching circuit, which receives a color signal of R%αB from the television signal reception processing circuit 15 when a remaining amount display signal is supplied from the remaining amount display signal generation circuit 14 during VTR operation. This is to temporarily cut off the power and instead supply a remaining amount display signal to the cathode ray tube 17.

In the color television receiver with a built-in VTR configured as described above, when the VTR main body is not in operation, no signal is derived from the remaining capacity display signal generation circuit 14. The R and G%B color signals obtained through reception processing are supplied to the cathode ray tube 17 via the color signal switching circuit 16, and the cathode ray tube 1
Regular television broadcasts are received on the screen of 7.

However, when recording or playback starts on the VTR main body side, the remaining capacity display signal generation circuit 14 is driven, and the horizontal synchronization signal (H) and vertical synchronization signal obtained from the television signal reception processing circuit 15 are activated. (V), a remaining capacity display signal is intermittently derived from the circuit 14 every predetermined scanning period of the cathode ray tube 17. This remaining amount display signal is supplied to the cathode ray tube 17 via the color signal switching circuit 16 in place of the color signal from the television digital reception processing circuit 15, and as a result, the lower part of the screen of the cathode ray tube 17 is displayed as shown in FIG. 9 shows the remaining amount of tape in units of 15 or 30 minutes.
rOJ, r
The numbers 60J and r180J are displayed simultaneously. The color of the mark displayed here will be explained later.AD converter 1
It is determined by the output information of step 3.

That is, first, the operation when recording or reproducing in the 6H mode (low speed mode) using a 60-minute recording cassette tape in the VTR body will be explained. In this case, the tape running speed is 1/1 during normal 2H mode recording and playback.
3, and at the start of recording and playback, the tape winding diameter on the supply reel side in the cassette is large, so the supply reel stand 1 is rotated at a relatively low speed, but as the recording and playback time elapses, the tape winding diameter on the supply reel side increases. becomes smaller and the rotational speed of the supply reel stand 10 gradually increases.

゛When the supply reel stand 1 rotates during recording and reproduction, the rotation speed of the supply reel stand 1 is detected by the light emitting diode 3 and the phototransistor 4, and 12 photos are output for every 1° rotation of the supply reel stand 1. Continuous rotation detection pulses are derived from the transistor 4 as shown in FIG. The detected signal is amplified by a pulse amplifier 5 and then supplied to a waveform shaper 6, where the waveform is shaped into a rectangular wave as shown in FIG. At this time, a rectangular wave pulse whose frequency has been divided by 1/2, for example, is derived from the frequency divider 7 via the changeover switch 8 and is supplied to the triangular wave generator 9, as shown in FIG.

The triangular wave generator 9 generates a triangular wave signal as shown in FIG. 2 based on the rectangular wave pulse, and the peak detector 1
0. The peak detector 10 detects the peak value of the triangular wave signal, and outputs a DC output in which the peak value is maintained, as shown in FIG. Immediately after the start of recording and playback, the rotational speed of the reel stand 1 is relatively low, but as the recording and playback time elapses, the rotational speed of the reel stand 1 gradually increases, so the output of the peak detector 10 gradually increases over time. becomes smaller. A bias suitable for a 60-minute recording cassette tape is applied to the DC amplifier 11 by a changeover switch 12, and the output of the amplifier 11 is adjusted to a value suitable for displaying the remaining amount of tape (time C minutes). A DC voltage is obtained, which is supplied to the AD converter 13. At this time, the remaining amount display signal generation circuit 14:
A remaining amount display signal having color information corresponding to the output of the converter 13 is generated, and this signal is supplied to the cathode ray tube 17 via the color signal switching circuit 16.

As a result, on the screen of the cathode ray tube 17, eight bars representing 0 to 180 minutes are initially displayed in blue, for example, and the remaining bar representing 180 minutes or more is displayed in red. Then, as the recording and playback time elapses, that is, the remaining tape capacity decreases, the color changes from blue to red, initially in 30 minute increments, then in 15 minute increments, and finally, when the remaining tape capacity decreases within 5 minutes, 1) 1z Starts blinking red at the cycle of. As a result, the viewer can see at a glance that the remaining amount of the cassette tape is low.

If the recording/reproducing operation is performed with the recording/reproducing mode of the VTR body switched from 6H mode to 2H' mode, the rotational speed of the supply reel 1 will triple and at the same time the mode selector switch 8 will change the recording/reproducing operation. The frequency division ratio of the frequency generator 7 is changed to an appropriate value, and the other operations are the same. In this case, on the screen of the cathode ray tube 17, four bars representing 0 to 60 minutes are first displayed in blue, the remaining three bars representing 60 minutes or more are displayed in red, and then four bars representing 0 to 60 minutes are displayed in red. The color changes from blue to red in 15 minute increments. Finally, the remaining bar flashes for 5 minutes, thus displaying the remaining amount of tape.

12 instead of a cassette tape for recording 60 minutes.
When performing recording and reproducing operations using a cassette tape for 0-minute recording, the tape changeover switch 12 is switched to change the bias of the DC amplifier 11.
As a result, the remaining amount of tape is displayed on the cathode ray tube screen in the same manner as described above, regardless of the difference in the hub diameter of the reel in the cartridge.

As described above, in this embodiment, in a color television receiver with a built-in VTR, the remaining amount of cassette tape is detected by detecting the rotational speed of the supply reel stand of the VTR main body, and the remaining amount of tape obtained at this time is is displayed using a part of the screen of a cathode ray tube, but the present invention is not limited to this embodiment, of course. For example, instead of a bar display, it would be possible to display the remaining amount of tape numerically on a cathode ray tube.

As described above, according to the VTR tape remaining amount display device of the present invention, a portion of the cathode ray tube screen of a television receiver is used to
Since the remaining capacity of the R cassette and tape is shown in Table 7F, there is no possibility of the viewer mistakenly recording a long program without noticing the remaining capacity of the tape, as was the case in the past. It is also possible to prepare a new cassette tape, which is very effective.

[Brief explanation of the drawing]

FIG. 1 shows a V using the tape remaining amount display device according to the present invention.
A block diagram of a television receiver with a built-in TR, Fig. 2 is a waveform diagram for explaining the operation of the tape remaining amount display device, and Fig. 3 is a waveform diagram for explaining the operation of the tape remaining amount display device. FIG. 14. Remaining amount display signal generation circuit, 15... Television signal reception processing circuit, 16... Color signal switching circuit, 1
7...Cathode ray tube.

Claims (1)

[Claims] 1. Remaining amount detection means for detecting the remaining amount of tape in the cassette during recording and playback operations of the VTR, and a VT detection means based on the detection output.
Remaining amount display signal generating means for generating a remaining amount indicating signal according to the remaining amount of tape during recording and reproducing operations of R, and a signal that superimposes or switches the remaining amount indicating signal on a television video signal and supplies it to a cathode ray tube. and a supply means, the VTR
A VTR tape remaining amount display device characterized in that the remaining amount of a cassette tape is displayed on a cathode ray tube screen at the time of one production.