JPS5880973A - Video system with detecting means for remaining amount of tape - Google Patents

Abstract

PURPOSE:To confirm the remaining amount of a tape easily, by placing a video tape recorder in a video recording state with a video camera, and supplying power to a detecting means for the remaining amount of a tape, and displaying its output on the video camera. CONSTITUTION:When a key switch SW provided to a video camera VIC is turned on, transistors TR1 and TR2 of a magnetic recording and reproducing device VRC turn on to supply power to a light emitting diode LED1 and a phototransistor PT, and light emitting diodes LED2 and LED3 turn on to show that the device is in recording mode and the remaining amount of a tape is sufficient. As the remaining amount of the tape becomes less, the phototransistor PT turns on by being irradiated with light and the oscillator consisting of inverters N2 and N3, resistances R3 and R4, and a capacitor C1 oscillates to flash the light emitting diodes LEDs 2 and 3, so an operator knows that the remaining amount of the tape becomes less.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video system for recording video information captured by a video camera on a tape, and relates to a video system equipped with a Puig retardation detection means for detecting the remaining amount of tape on the shaft. 1-ru.

Conventionally, various methods for detecting the remaining amount of tape have been proposed.

An object of the present invention is to provide a video system that is easy to use and is equipped with a remaining tape amount detection means.

Hereinafter, application examples of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 are diagrams showing how to detect the remaining amount of tape using light. In the figure, 10.10' is a magnetic tape cassette, 1
1.11' is the magnetic tape, 12.12' is the supply reel, 15, 14.18 is the opening provided in the cassette 10° 10', and 15.15' is the magnetic recording/reproducing device (v'nt).
Near fcIJ-A/44M, 16.16' is a light emitting diode, 17. 17'+x no A- transistor.

In FIG. 1, if the tape 11 is wound with enough remaining on the supply reel 12, the light emitting diode 16
The light from the phototransistor 17 does not reach the phototransistor 17. However, when the sit of the tape 11 decreases, the light emitting diode 1
The light from 6 reaches the photodiode 17 through the aperture 15.

In FIG. 2, tape 11' is shown on supply reel 12'.
When the light emitting diode 16' is wound with enough remaining light, the light from the light emitting diode 16' is disturbed by the step on the side of the tape, and is absorbed by the tape 11', so that most of the light emitted from the transistor 17'
Don't delay your sword. However, when there is only a small amount of light remaining on the tape 11', the light from the light emitting diode 16' is reflected by the light emitting diode 16' inside the housing of the cassette 10', passes through the 18' 18, and is delivered to the phototransistor 17'. It is desirable that the inner surface 19 be mirror-finished.

In FIGS. 1 and 2, it is the same that the amount of tape Y4 is detected based on the difference in light entering the phototransistors 17 and 17' as light receiving elements.

Figure 83 shows a circuit diagram of an embodiment of the present invention. r1゜Fi
l, 2 are transistors, R1-, JLs are resistors, C1 is a capacitor, D is a diode, LgDl is Fig. 1, Fig. 2
Light-emitting diode, LED, which is 6 against the evil 16, 16'
2 is a light emitting diode provided in the viewfinder of the video camera, LED 6 is a light emitting diode provided in the operation section of the VT), and PI3'' is 17.17' in Figure 1.2.
phototransistors corresponding to , N1 to N4 are C@M)
8 inverter, so-called key switch that connects contacts 80 and 82 to set the video camera to V'l'Rvk recording mode.Also, K1 is opened due to inconveniences such as binding of the VTR drum or insufficient voltage of the power supply. It is a relay contact.

When the so-called key switch provided in the video camera is in the connected state, the transistor '1'r1. Tr2 turns on, light emitting diode IJD1 and phototransistor Pr1
(Power is supplied. When there is enough remaining tape, the phototransistor H' does not turn on, so the inverter input 0 input level is high level (hereinafter referred to as "H")) -9, tB level is low level (hereinafter referred to as "H")) τ). Therefore, the output of inverter N2 is "H", the output of Ns is "L",
The output of Na becomes “111” and the light emitting diode LED
2. LkA) 5 fishes and informs the video camera operator that the video cheap recorder is in recording mode and that there is sufficient tape remaining. Even if the switch is turned on here, LhilJ2 will not light up if the contact 1 is open due to a problem with Yvl.

Next, when the remaining amount of tape becomes low,
TK light is irradiated [,? r is turned on. Then, the input of inverter N1 becomes L1, and the output of N1 becomes g Ha'',
Therefore, diode D is in a cut-off state. For this reason, inverter N2. N5. An oscillator composed of resistors B, S, R4, and capacitor C1 oscillates at a frequency determined by the resistance value of resistor R4 and the capacity of capacitor C1. Therefore, [output %fk4 of inverter N4].

@ Repeat L ++t Light emitting diode IJD2,3
flashes. Therefore, the photographer operating the video camera can know that the number of 7-pixels remaining is low by the blinking of the light emitting diode L13D2.

Further, when the LED 2 does not light up, the photographer can know that the VTR is not in recording mode or that a VTRK problem has occurred.

Also, the ON & C switch of the recording key on the YIR side is the transistor Tr1. Turn on Tr2, when the broadcast from the broadcast station starts. 4. t, Wi) 3 blinks to notify the user that the remaining amount of Arg is low.

As described above, the present invention allows video cameras to
In order to put the video recorder into the recording state, power is supplied to the tape remaining amount detecting means, and the output of the detecting means is displayed in the finder of the video camera. The photographer runs out of tape when using it.
! You can know when the tape is running low, you won't make a mistake in changing the tape, and you won't be afraid to make a difficult arrangement. It also reduces power consumption. In addition, in this example, the internal structure of the turtle finder, which uses the VTIL or recording mode display and the tape fin display, is simplified, allowing the user to concentrate on shooting. Kotokade 6゜

[Brief explanation of the drawing]

Figures @1 and '@2 are cross-sectional views showing the structure of the Tef'AMt* output device, and Figure 6 is a diagram showing an example of the control circuit. In the figure, 10.10' is a cassette, 11.11' is a magnetic tape, 12.12' is a supply reel, 16° 14
．． 18 is an aperture, 16.16' is a light emitting diode, 17.
17' is a phototransistor, island is a switch, K1
is a relay contact, IJD 1.2.3 is a light emitting diode,
(2) indicates phototransistors, respectively. Applicant Canon Co., Ltd. Agent Sage Marushima −;y”, 2zu,, −
one

Claims (2)

[Claims] (1) In a video system in which video information captured by a video camera is recorded on a tape by a video tape recorder, there is a remaining lid detection method for detecting that the jA lid of the tape is below the standard lid. and a display means for displaying the detection output of the means in a finder of the video camera, and is characterized in that power is supplied to the detected hand gesture by putting the video tape recorder into a recording state by the MIJ video camera. A video system equipped with a tape IAj11 side output means. (2) The video system as set forth in paragraph 1 of Inishi 4 of Tokuken Fukyuu, characterized in that the display means also serves as a display device for displaying the recording state.