JPH0447388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording device, and more particularly, to recording on a magnetic recording medium by arbitrarily selecting one of two modes in which the carrier wave frequency of a frequency-modulated video signal is different from each other. The present invention relates to a magnetic recording device.

Conventional technology Currently, home VTRs that use 1/2-inch wide magnetic tape use iron oxide magnetic tape (hereinafter referred to as the "standard approximately 3.4MHz to 5.5M on this standard tape.
Carrier frequency set between Hz (e.g. 3.4M
Hz to 4.4MHz) frequency modulated video signals (FM video signals), but in recent years, the characteristics of magnetic tape and the performance of magnetic heads have improved, and VTRs with higher resolution and higher images are now in demand. It's starting to be done.

For this reason, instead of the standard tape mentioned above, we are currently using 8mm tape.
This metal tape uses metal tape with high coercive force and high residual magnetic flux density, such as those used in VTRs and commercial VTRs, with a coercive force of about 1300 Oe to 1500 Oe and a residual magnetic flux density of about 2700 Gauss to 2800 Gauss. The above carrier frequency is sufficiently higher than that used in current home VTRs (e.g.
Various VTRs have been considered that record FM video signals set at 5MHz to 7MHz.

Therefore, the recording and playback mode in the current 1/2-inch home VTR is called standard mode,
The carrier frequency is set sufficiently higher than this.
If the mode for recording and reproducing FM video signals is called high-quality mode, the carrier wave frequencies of these two modes are significantly different from each other, so there is no compatibility between the recording signals of the two modes. In addition, the above 8mm
Existing high-performance tapes such as metal tapes used in VTRs and commercial VTRs have an extremely high coercive force of approximately 1300 Oe or more compared to the standard tapes mentioned above.
This high-performance tape can be used on current 1/2-inch home VCRs.
If you record using a standard It cannot be used in the high-quality mode, and can only be used in the high-quality mode.

Furthermore, the above-mentioned standard tape cannot be used in the high-quality mode due to its performance, but can only be used in the standard mode.

Therefore, in order to meet the above-mentioned demands, we need a high-definition mode dedicated VTR equipped with new high-definition mode recording and playback means, and a high-definition mode VTR that accommodates the metal tape used in the above-mentioned 8mm VTR and commercial VTR. However, in this case, the user would have to prepare two types of VTRs and two types of tape cassettes corresponding to each mode, which are incompatible with each other, and try to record and play back on them. It is necessary to use it properly depending on the mode, which makes it expensive and extremely inconvenient for the user.

Therefore, in addition to having the recording and reproducing system for the standard mode and the recording and reproducing system for the high image quality mode,
While we provide a dual-mode VTR that has a switch to switch between these two recording and playback systems depending on the mode, we also offer tape cassettes containing existing metal tapes used in 8mm VTRs and professional VTRs that can be used in the same VTR. In order to be able to
It is conceivable that the shape be the same as an existing tape cassette that stores standard tapes, so that the user can identify both tape cassettes and switch to any mode.

Problems to be Solved by the Invention However, in this case, since the cassette cases have the same shape, it is possible to use an existing tape cassette containing a standard tape (hereinafter referred to as a "standard cassette") or a metal cassette. It is easy to make mistakes in identifying whether it is a tape cassette containing a tape, and it is very troublesome to identify each tape one by one and switch modes.For example, it is a standard cassette (or a tape cassette containing metal tape). However, it is easy to make mistakes when recording in high quality mode (or standard mode).

Furthermore, it is quite conceivable that a user who owns a current standard-mode VCR may purchase and use a tape cassette containing the metal tape mentioned above, mistaking it for a standard cassette, and may purchase either tape cassette. This may cause some inconvenience, such as confusion as to whether it is okay to do so, which is not desirable.

The present invention was created in view of the above points,
It is an object of the present invention to provide a magnetic recording device that solves all of the above problems.

Means for Solving the Problems The magnetic recording device of the present invention includes a first recording system that generates a frequency modulated video signal in a first mode, and a first recording system that generates a frequency modulated video signal in a second mode. a first tape cassette containing a magnetic tape that can be recorded only in the first mode; A cassette discriminating means for discriminating which tape cassette is installed among the second tape cassette having a hole, a selection switch, and a selection switch that is operable or inoperable depending on the type of the determined tape cassette. and a recording means for selectively outputting one of the output frequency modulated video signals of the first and second recording systems and recording it on the magnetic tape in the tape cassette installed.

Operation: The cassette discriminating means automatically discriminates which of the first and second tape cassettes is installed based on the presence or absence of the cassette discriminating hole. If the tape cassette determined by the cassette determining means is the second tape cassette, the selection switch is made operable, and the recording means selects the first recording mode according to the recording mode selected by the selection switch. A frequency modulated video signal from the system or the second recording system is selectively outputted and recorded on the magnetic tape in the second tape cassette.

Here, the coercive force, residual magnetic flux density, and particle length of the magnetic tape in the second tape cassette are set so that recording can be performed in both the first and second modes. An existing first mode frequency modulated video signal with a carrier frequency lower than the carrier frequency of the frequency modulated video signal can also be recorded.

On the other hand, when the first tape cassette is determined by the cassette determining means, the selection switch is made inoperable, and the recording means automatically selects the output frequency modulated video signal of the first recording system. The data is output and recorded on the magnetic tape in the first tape cassette.

Embodiment FIG. 1 shows a block system diagram of an embodiment of the apparatus of the present invention. In the figure, a composite video signal (composite color video signal) is input to input terminal 1, and a luminance signal and a carrier color signal are respectively input to input terminals 2 _Y and 2c as separate video signals. When the video signal to be recorded is a composite video signal, the switch 3 is connected to contacts A and C, respectively, and passes the composite video signal from the input terminal 1 through a low-pass filter (LPF) with a cut-off frequency of about 3MHz and a comb type. It is supplied to a filter 4a, an LPF with a cutoff frequency of about 5 MHz, and a comb filter 4b to separate the luminance signal, while it is supplied to a bandpass filter (BPF) 8 to separate the carrier color signal. When the video signal to be recorded is a separate video signal, the changeover switch 3 is connected to contacts A and D, respectively, and the luminance signal from the input terminal _2Y is supplied to the LPF and comb filters 4a and 4b, respectively. , input terminal 2c
The carrier color signal is supplied to BPF8.

The circuit consisting of the LPF, comb filter 4a, pre-emphasis circuit 5a and FM modulator 6a constitutes a standard mode (first mode) recording system, which is the luminance signal recording system of the current 1/2-inch home VTR. The same frequency modulated luminance signal (FM luminance signal) is generated. As a result, from the FM modulator 6a, as shown by _YA in FIG.
4.4MHz carrier frequency deviation (carrier deviation band)
An FM luminance signal with .

On the other hand, the circuit consisting of the LPF, the comb filter 4b, the pre-emphasis circuit 5b and the FM modulator 6b constitutes the recording system of the high image quality mode (second mode), and compared to the FM luminance signal of the standard mode, the carrier wave Generates a wideband FM luminance signal with a high frequency band and a wide carrier frequency shift. As a result, from the FM modulator 6b, the
As shown by Y _B in , an FM luminance signal having a wide carrier frequency shift is extracted, for example, the carrier frequency corresponding to the sync chip level is 5.4 MHz, and the carrier frequency corresponding to the white peak level is 7.0 MHz.

The above FM brightness signals Y _A and Y _B are the switch circuit 7
is supplied to terminals A and B of. As will be described later, the switch circuit 7, based on the switching signal from the AND gate 17, selects either the standard cassette shown in FIG. 3 or the tape cassette shown in FIG. When recording in standard mode on a magnetic tape in a high-performance cassette, the FM luminance signal _YA is connected to terminal A and is selectively output to the adder circuit 10, which records high-quality images on a high-performance magnetic tape in a high-performance cassette. When recording in mode, the FM brightness signal is connected to terminal B.
Selectively output Y _B to the adder circuit 10.

On the other hand, the carrier color signal extracted from the BPF 8 is supplied to the recording chroma processing circuit 9, where it is processed into a color signal in the same frequency band as the low frequency converted carrier color signal recorded and played back on the current 1/2-inch home VTR. After being converted into a low frequency converted carrier color signal with a subcarrier frequency of approximately 629 kHz, it is supplied to the adder circuit 10. The frequency spectrum of this low-pass converted carrier color signal is shown in Figure 5A.
C _A is shown in FIG. 1, _and C _{B is} shown in FIG.

As a result, a frequency division multiplexed signal with a frequency spectrum as shown in FIG. 5A is taken out from the adder circuit 10 when recording in standard mode, and a frequency division multiplexed signal with a frequency spectrum as shown in FIG. 5B is taken out when recording in high quality mode. Multiplexed signals are extracted. This frequency division multiplexed signal is supplied to rotary heads 12 and 13 through a recording amplifier 11, and thereby recorded on a magnetic tape 25.

As shown in FIG. 2, during recording and reproduction, this magnetic tape 23 is pulled out from a supply reel 27 in a tape cassette 26, passes through an impedance roller 28, a full-width erasing head 29, a loading post 30, and then is transferred to the rotary head 12, 13 is obliquely wound around the rotating cylinder 31, which is mounted opposite to the rotating surface thereof, over an angular range of more than 180°. The magnetic tape 23 further passes through a loading post 32, an audio erasing head 33, an audio/control head 34, is pinched by a capstan 35 and a pinch roller 36, and then reaches a take-up reel 38 in a tape cassette 26. In addition,
The loading posts 30 and 32 are at positions 30a and 32a shown by two-dot chain lines during unloading.

The above is a well-known tape running system for home VCRs, but in this embodiment, the changeover switch 3 and the selection switch 14 shown in FIG. 1 are provided, and the tape cassette 26
A cassette discriminating pin 39 is installed at a position opposite to a predetermined position of the cassette discriminating pin 39, which is configured to move up and down by the action of a spring, for example. Further, the recording mode display device 18 shown in FIG. 1 is provided on the front panel surface of the recording apparatus shown in FIG.

By the way, in the apparatus of the present invention, one of two types, a standard cassette and a high-performance cassette, is selected and used as the tape cassette 26.
Next, the standard cassette and high performance cassette will be explained.

Figure 3 is a perspective view of a well-known standard cassette.Standard cassette 41 is a tape cassette currently used in 1/2-inch home VCRs, and is made of iron oxide magnetic tape (with a coercive force of about 600 Oe to 730 Oe, residual magnetic flux density is about
1100 Gauss to 1300 Gauss) is stored. In the figure, 42a is an upper cassette half, 42b is a lower cassette half, and 42b is a lower cassette half.
Shaft holes 43a, 43b, capstan insertion recess 44, tape drawer member insertion recess 45a, 45
b. A recess 46 for preventing erroneous insertion is provided, and a lid 47 is provided so as to be openable and closable.

Figure 4 shows a perspective view of the high performance cassette;
Components that are the same as those in the figures are given the same reference numerals, and their explanations will be omitted. The high-performance cassette 49 has substantially the same shape and size as the standard cassette 41, and has a hole 50 for cassette identification in a part of the recess 46 for preventing incorrect insertion, and a magnetic field inside the cassette 49. The only difference from the standard cassette 41 is that the tape is a high performance magnetic tape.

The high-performance magnetic tape housed in this high-performance cassette 49 is different from the metal tape described above, and has a luminance signal recording wavelength of 1.3 μm.
At 0.97μm and 0.73μm, the playback output value when recording at a current approximately 20% higher than the optimal recording current value of the standard tape used in current 1/2-inch home VTRs is the maximum output of the standard tape. For example, use a Co-coated iron oxide magnetic material for the magnetic layer and have a coercive force of 750 Oe to 950 Oe so that the audio signal erasure rate is better than -65 dB. , the residual magnetic flux density is at least 1250 gauss or more, and the grain length of the magnetic layer is at least 0.2 μm or less, or the magnetic layer is made of a metal magnetic material and the coercive force is
700Oe~850Oe, residual magnetic flux density is 2600 Gauss~
2800 Gauss, magnetic layer grain length at least 0.16μ
m or less. This high-performance magnetic tape can record in both standard mode and high-quality mode.

Next, the above two types of tape cassettes 41, 4
The determination operation No. 9 and the switching operation of the recording system based on the determination operation will be explained.

Now, when the standard cassette 41 is installed in the device shown in FIG. 2, the cassette discrimination pin 39 is displaced downward by the erroneous insertion prevention recess 46, so that the cassette discrimination circuit 15 shown in FIG. A standard cassette discrimination signal is extracted and applied to one input terminal of the two-input AND gate 17 to close the gate, and is also applied to the DC motor 20 through the motor drive circuit 19 to rotate it in the opposite direction. . However, as will be described later, when the load on the DC motor 20 is at a predetermined position, it does not rotate.

On the other hand, a high-performance cassette 49 is installed in the apparatus shown in FIG.
When the cassette identification pin 39 is inserted into the cassette identification hole 50 shown in FIG. Remain stationary in position.

In this case, since the cassette identification hole 50 is protected by the stepped portion of the erroneous insertion prevention recess 46, the intrusion of dust and the like can be prevented as much as possible. Furthermore, when the high-performance cassette 49 is inserted into the installed holder, the cassette discrimination pin 39 and the cassette discrimination hole 50 engage with each other at the same time as the holder descends.
Both the groove and the stepped portion of the erroneous insertion prevention recess 46 serve as guides, and the engagement between the two is ensured.

As a result, the cassette discrimination circuit 1 shown in FIG.
A high-level high-performance cassette discrimination signal is taken out from 5, opens the AND gate 17, and is applied to the DC motor 20 through the motor drive circuit 19 to rotate it in the forward direction.

A signal obtained by inverting the polarity of the output signal of the selection switch 14 by an inverter 16 is applied to the other input terminal of the AND gate 17. Figures 1 and 2
The selection switch 14 shown in the figure is a switch operated by the user depending on the mode in which the user intends to record out of the standard mode and high-quality mode.It outputs a high-level signal when recording in the standard mode, and outputs a low-level signal when recording in the high-quality mode. Outputs a level signal.

The selection switch 14 can be operated by the user by rotating the DC motor 20 in the forward direction.
It has a structure in which it can be switched from an operable state to an inoperable state by rotating the DC motor 20 in the opposite direction. Next, each embodiment of this mechanical structure will be described.

6 and 7 show the operation of the selection switch 14,
3 shows the operating states of the first embodiment of the mechanism for determining non-operation in both modes. The DC motor 20 is fixed at a predetermined position, and its rotating shaft is
As shown in FIG. 7B and FIG. 7B, a gear 52 is fixedly fixed therethrough, and the gear 52 meshes with a semicircular toothed rail 53 having toothed shapes formed on the inner surface.
One end of the toothed rail 53 is connected to a bottom surface 54, as shown in FIGS. 6B and 7B, respectively, and these are configured to be integrally rotatable about a fulcrum 55. Further, the projection 5 is configured so as to come into contact with a stopper 57 provided at the top of an opening bored at a predetermined position in the front panel 56 of the device. The selection switch 14 is moved and displaced integrally with the toothed rail 53 and the resistor 54, respectively.
It has a so-called retractable structure.

Here, when a low level standard cassette discrimination signal is taken out from the cassette discrimination circuit 15,
A drive voltage is applied to the DC motor 20 to rotate it in the opposite direction, and this applies a force to rotate the selection switch 14 and the like clockwise about the fulcrum 55, but as shown in FIG. 6B, When the protrusion 58 comes into contact with the stopper 57, the rotational force is regulated, and it does not rotate any further and remains stationary in that state. Therefore, when the standard cassette is installed, the selection switch 14 is housed in the front panel 56 as shown in FIGS. It is considered impossible to operate.

On the other hand, when a high-level high-performance cassette discrimination signal is taken out from the cassette discrimination circuit 15,
Since the rotating shaft of the DC motor 20 is rotated counterclockwise (positive direction) in FIG. 7B, the selection switch 14 is exposed to the outside of the front panel 56, as shown in FIGS. 7A and 7B, respectively. The user can now operate the selection switch 14.

8 and 9 show the operation of the selection switch 14,
The operating states of the second embodiment of the mechanism for determining non-operation in both modes are shown. In the drawings, the same components as in FIG. 1 are designated by the same reference numerals. DC motor 20
The gear 60 fixed through the rotating shaft is shown in FIG. 8B,
As shown in FIGS. 9B and 10, it is meshed with a gear portion 62 provided on a part of the door 61. Further, the door 61 is provided at a predetermined position on the front panel 63 of the device and is movable on the front side of the selection switch 14. Further, the selection switch 14 is always fixed.

As a result, when the standard cassette discrimination signal is output,
As shown in FIGS. 8A and 8B, the door 61 is stopped at a position where the door 61 covers the front surface of the selection switch 14, making it impossible for the user to operate the selection switch 14 from the outside.

Furthermore, when a high-performance cassette discrimination signal is output, the rotating shaft of the DC motor 20 and the gear 60 are rotated in the forward direction, thereby causing the door 61 to move in the direction shown in FIGS. 9A and 9B.
The selection switch 14 is exposed to the outside because it is moved toward the center and right. As a result, the selection switch 14 becomes operable from the outside. Note that FIG. 9 is a partially cutaway front view, and in reality, the DC motor 20, gear 60, and gear portion 62 are not visible from the outside.

FIG. 11 shows a schematic structure of a third embodiment of a mechanism for determining whether the selection switch 14 is operated or not. In the figure, the same components as in FIG. 1 are given the same reference numerals. The DC motor 20 is fixed, and a worm 65 is attached and fixed to its rotating shaft. Also, the worm gear 6 meshing with the worm 65
6 has a pinion 67 fixedly attached to its central shaft. Furthermore, a rack 68 that meshes with the pinion 67
is connected to a housing 69 that houses the selection switch 14. As a result, the housing 69 is moved to the opening 71 provided at a predetermined position in the front panel 70 of the device by the forward rotation of the DC motor 20, and the housing 69 is moved by the reverse rotation of the DC motor 20. The device is then moved to the back of the device.

Therefore, when the standard cassette discrimination signal is output, the housing 69 is moved to a position deep inside the device as shown in FIG.
cannot be operated. Furthermore, when the high-performance cassette discrimination signal is output, as shown in FIG. 13, the housing 69 is moved to the position of the opening 71 and remains there, so that the selection switch 14 is exposed on the front panel 70, allowing the user to It becomes operational. Rack 6
If only the worm 8 and the pinion 67 are used, there is a risk that the selection switch 14 will move due to the force when operating the selection switch 14. However, in this embodiment, the selection switch 14 is
5 and the worm gear 66 are further combined, so there is no such fear at all.

Returning to FIG. 1 again, the power off detection circuit 21 detects when the power switch is switched from on to off, and the motor drive circuit 1
A driving voltage for reverse rotation is generated and outputted to the DC motor 20 through 9. As a result, when the power switch is turned off, the selection switch 14 is rendered inoperable, the same as when the standard cassette 41 is loaded, even when the high-performance cassette 49 is loaded. Therefore, the selection switch 14 is normally not operable from the outside, and becomes operable only when the high-performance cassette 49 is loaded into the apparatus for recording.

When the standard cassette 41 is installed in the device, the output signal of the AND gate 17 automatically becomes low level, and the switch circuit 7 is connected to the terminal A side and selectively outputs the standard mode FM luminance signal. Therefore, a standard mode frequency division multiplexed signal as shown in FIG. 5A is recorded on the magnetic tape in the standard cassette 41. At the same time, the recording mode display device 18 displays that the recording mode is the standard mode.

Furthermore, when the high-performance cassette 49 is installed in the apparatus, the selection switch 14 as described above becomes operable, so when standard mode recording is selected by the selection switch 14, the AND gate 17
The output becomes low level, and as in the case above, the switch circuit 7 selectively outputs the standard mode FM luminance signal, and the recording mode display device 18
to display that the recording mode is the standard mode.

On the other hand, when the high-performance cassette 49 is installed in the apparatus and high-quality mode recording is selected by the selection switch 14, the output signal of the AND gate 17 is at a high level, unlike in the above case, so that the switch circuit 7 It is switched and connected to the terminal B side, and the FM brightness signal in high image quality mode is selectively output. As a result, a high-quality mode video signal having a frequency spectrum as shown in FIG. 5B is recorded on the high-performance magnetic tape in the high-performance cassette 49. Also,
The recording mode display device 18 uses a high level signal from the AND gate 17 to display that the recording mode is a high image quality mode.

By the way, as mentioned above, it is not possible to record on the standard tape in the standard cassette 41 in the high image quality mode. However, since the selection switch 14 is provided on the panel surface, users may misunderstand that not only the high-performance cassette 49 but also the existing standard cassette 41 can be used for recording in both modes, and may attach the standard cassette 41 to the device. There may be cases where an operation is performed to select recording in high-quality mode.

However, according to the present invention, when the standard cassette 41 is installed in the device as described above, the selection switch 14 is automatically rendered inoperable.
The above-mentioned erroneous operations can be prevented and misunderstandings can be eliminated.

In this embodiment, in the above case, even if high image quality mode recording is selected by the selection switch 14, the loaded tape cassette is not the standard cassette 4.
1, a low-level standard cassette discrimination signal is taken out from the cassette discrimination circuit 15, which causes the output signal of the AND gate 17 to become low level, and the switch circuit 7 selects and outputs the standard mode FM brightness signal, so that recording is not possible. will be performed in standard mode, and there seems to be no practical problem. However, in this case, the actual recording mode and the recording mode selected by the selection switch 14 are different,
Even though the user judges that recording is being performed in the high-quality mode selected with the selection switch 14, recording is actually being performed in the standard mode, and even in the standard cassette 41, both This is undesirable because it gives the user the misunderstanding that it is possible to record the mode.

Next, means for identifying other types of tape cassettes will be explained. Although FIGS. 4 and 5 show standard-sized tape cassettes used in 1/2-inch home VCRs, the present invention is not limited to this;
It is also possible to determine the type of existing small cassette shown in the perspective view of the figure.

15A and 15B are a perspective view and a rear view of a standard small cassette 73, in which a standard tape is stored. 16A and 16B are a perspective view and a rear view of a high-performance small cassette 74, which stores a high-performance magnetic tape capable of recording in both standard mode and high image quality mode, and is substantially the same as the standard small cassette 73. Same shape and same size, but with identification hole 7 on the back.
5 is provided. By detecting the presence or absence of this discrimination hole 75 using a discrimination switch means such as a leaf spring in the apparatus, a high-performance small cassette 74 or a standard small cassette 73 is detected.

Also, the small cassettes 73 and 74 are of standard type.
When used attached to a VTR, it is housed in an adapter 77 shown in FIG. 17 and attached to the VTR. In this case, when the standard small cassette 73 shown in FIG. 15 is attached to the adapter 77, the identification hole 78 on the back surface of the adapter 77 is closed as shown in FIG. 17B. On the other hand, the high-performance small cassette 7 shown in FIG.
4 is attached to the adapter 77, the identification hole 78 on the back side of the adapter 77 is opened as shown in FIG. 17B. Therefore, by detecting the opening and closing of the discrimination hole 78, it is determined whether the cassette is a standard small cassette 73 or a high performance small cassette 74.

It should be noted that the present invention is not limited to the above embodiments, but also includes various other modifications. For example, in the recording amplifier 11 shown in FIG. 1, the characteristics and magnitude of the recording current may be changed as necessary depending on the characteristics of the magnetic tape used. It is also possible to provide recording amplifiers set to desired characteristics and sizes in accordance with the characteristics of each magnetic tape, and to switch these amplifiers by the output signal of the AND gate 17.

Effects of the Invention As described above, according to the present invention, there is no need to perform complicated operations such as identifying each tape cassette one by one and switching modes, so it is easy to use, and when a standard cassette is installed, Since the selection switch is made inoperable, it is possible to reliably prevent erroneous recording of video signals in high-quality mode on the magnetic tape in a standard cassette, and the selection switch can also be disabled when a high-performance cassette is installed. Either mode can be selected by operating the switch, making it easy to use.Furthermore, the cassette identification hole is protected by the step in the recess to prevent incorrect insertion, preventing dirt from entering. In addition, when inserting a cassette into a holder for another device, the groove and stepped portion of the recess for preventing erroneous insertion serve as guides to ensure engagement between the two. .

[Brief explanation of the drawing]

Fig. 1 is a block system diagram showing an embodiment of the device of the present invention, Fig. 2 is a schematic plan view showing an embodiment of the main mechanism of the device of the invention, and Fig. 3 shows the external appearance of an example of a standard cassette. 4 is a perspective view showing the external appearance of an embodiment of a high-performance power cassette that can be used in the device of the present invention, and FIG. 5 is a diagram showing the frequency spectrum of the signal recorded by the device of the present invention. 6 to 13 are schematic diagrams for explaining each embodiment of the mechanism for determining whether or not to operate the selection switch, respectively;
Figures 14 and 15 are views showing the appearance of an example of a standard small cassette, Figure 16 is a view showing the appearance of an embodiment of a high performance small cassette that can be used in the device of the present invention, and Figure 17 is an adapter. FIG. 3 is a diagram showing the appearance of one embodiment of the invention. 1... Composite video signal input terminal, 2 _Y ...
... Luminance signal input terminal, 2c ... Carrier color signal input terminal, 3 ... Changeover switch, 6a, 6b ... FM modulator, 7 ... Switch circuit, 12, 13 ... Rotating head, 14 ... Selection switch, 15...Cassette discrimination circuit, 17...AND gate, 18...Recording mode display device, 20...DC motor, 21...
...Power off detection circuit, 23...Magnetic tape, 39
...Cassette identification pin, 41...Standard cassette, 49...High performance cassette, 50, 75...Cassette identification hole, 73...Standard small cassette, 7
4...High performance small cassette, 78...Identification hole.

Claims (1)

[Scope of Claims] 1. A frequency-modulated video signal in a first mode in which the carrier frequency is lower among two types of first and second modes in which the carrier wave frequencies of the frequency-modulated video signal to be recorded are different from each other. a first recording system that generates a frequency-modulated video signal of a second mode in which the carrier frequency is higher than that of the first mode and the carrier frequency polarization is set wider. a recording system, a first tape cassette containing a magnetic tape that can be recorded only in the first mode, and a magnetic tape that has coercive force, residual magnetic flux density, and particles so as to be recordable in both the first and second modes; Magnetic tapes with respective lengths are stored, and the first magnetic tape is stored in the cassette housing.
a second tape cassette having a cassette discrimination hole for distinguishing it from the second tape cassette, and a cassette discrimination means for discriminating which tape cassette is installed; and recording the first and second modes. a selection switch for arbitrarily selecting one mode; a selection switch operable when the tape cassette determined by the cassette determination means is the second tape cassette; and when determining the first tape cassette; means for disabling the selection switch; and when the second tape cassette is determined by the cassette determination means, the first recording system or the second tape cassette is selected according to the recording mode selected by the selection switch. A frequency modulated video signal is selectively outputted from the recording system and recorded on the magnetic tape in the second tape cassette, and when the first tape cassette is determined by the cassette discriminating means, the first recording system The first frequency modulated video signal is selected and outputted.
1. A magnetic recording device comprising a recording means for recording on a magnetic tape in a tape cassette.