JP2000030420A - Video tape recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video tape recorder capable of displaying tape remaining time for a plurality of recording modes. SOLUTION: This video tape recorder capable of performing reserved program recording by a plurality of recording modes on a plurality of cassettes 1 different from each other in tape lengths is provided with a tape kind detecting part for detecting the tape lengths of the plurality of cassettes 1, and a tape remaining time detecting part for detecting tape remaining time for the plurality of recording modes based on the tape lengths of the cassettes 1 obtained by the tape kind detecting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a video tape recorder having a function of searching for information recorded on a magnetic tape.

[0002]

2. Description of the Related Art Conventionally, VTR (Video Tape Recorder)
As a first means for retrieving information recorded on a magnetic tape, there is a method of recording a cue signal by modulating a duty ratio of a servo control signal at the beginning of information to be taken out from the magnetic tape. A so-called VHS standard VISS search function, which is the mainstream of home 1 / 2-inch VTRs, is a fast forward / rewind (FF / RE)
In this state, the cue signal (VISS signal) is detected in the state (W), and the state is shifted to the stop state or the reproduction state. The second means is a counter search function using a linear time counter function for displaying a count value of a servo control signal. In the FF / REW state, a counter value corresponding to the beginning of information to be taken out from the magnetic tape is obtained. If it is, it is shifted to the stop or playback state.

[0003]

However, in the above-described conventional configuration, when searching for information recorded on a magnetic tape, the current absolute position of the magnetic tape is unknown, and the remaining tape time is determined for each of a plurality of types of recording modes. Cannot be displayed.

[0004]

In order to achieve this object, a VTR according to the present invention is a video tape recorder capable of recording a program reservation in a plurality of types of recording modes in a plurality of types of cassettes having different tape lengths. A tape type detection unit for detecting the tape lengths of a plurality of types of cassettes, and a tape remaining time for detecting the remaining time of the tape for each of a plurality of types of recording modes based on the tape lengths of the cassettes obtained by the tape type detection unit. A detection unit.

With this configuration, the remaining tape time can be displayed for each of a plurality of types of recording modes.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
A video tape recorder capable of programming and recording a program in a plurality of types of recording modes for a plurality of types of cassettes having different tape lengths, a tape type detecting unit for detecting the tape length of the plurality of types of cassettes, and a tape type detecting unit The video tape recorder is provided with a tape remaining time detecting unit for detecting the remaining time of the tape for each of a plurality of types of recording modes based on the tape length of the cassette obtained by the above. The use of the output of the time detection unit has an effect that the remaining tape time can be displayed for each of a plurality of types of recording modes.

According to a second aspect of the present invention, the tape type detector detects the tape type based on the output of the tape speed detector, the output of the S reel rotation speed detector, and the output of the T reel rotation speed detector. The video tape recorder according to claim 1, wherein the tape type can be specified by calculating the tape area of the tape type.

According to a third aspect of the present invention, in the tape remaining time detecting section, the output of the tape speed detecting section, the output of the S reel rotational speed detecting section, the output of the T reel rotational speed detecting section, and the tape thickness are provided. 2. The video tape recorder according to claim 1, wherein the remaining tape time is detected for a plurality of recording time modes having different tape speeds based on the information and the hub diameter information. There is an effect that the remaining tape time can be specified by the calculation using the information, the hub diameter information, and the tape speed.

According to a fourth aspect of the present invention, there is provided the video tape recorder according to the first aspect, further comprising a display unit for displaying a remaining tape time for each of a plurality of types of recording modes. In addition, the presence of the display unit has an effect that detection information can be known without having an external display device.

According to a fifth aspect of the present invention, there is provided the video tape recorder according to the first aspect, wherein the remaining time of the tape can be displayed before the start of recording. Has the effect that erroneous recording can be prevented.

An embodiment of a video tape recorder according to the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a video tape recorder according to Embodiment 1 of the present invention. A cassette 1 for storing a magnetic tape 2, a rotating drum 3 having a rotating head (not shown) for recording and reproducing information on and from the magnetic tape 2, a supply reel (hereinafter referred to as a reel) for sending out the magnetic tape 2 during reproduction and fast-forwarding , S
A take-up reel (hereinafter, referred to as a T reel) 5 that winds up the magnetic tape 2 at the time of reproduction or fast-forward.
And a supply-side reel rotation speed detector (hereinafter, referred to as an S-reel rotation speed detector) 6 that detects the rotation speed of the S reel 4.
And a take-up reel rotation speed detector (hereinafter referred to as a T reel rotation speed detector) 7 for detecting the rotation speed of the T reel 5.
A control head 8 for recording and reproducing control signals for servo, a bar code 9 for recognizing the cassette 1, a bar code reader 10 for reading the bar code 9, and a magnetic tape 2 via the control head 8.
A control signal recording / reproducing circuit 12 for writing / reading a cue signal, and a capstan motor (not shown) or a reel motor (not shown) for transferring the magnetic tape 2 in accordance with the FF / REW state or reproduction state of the VTR. (Not shown), a key input device 14 for timer reservation, VTR operation, and the like, and index information on information to be recorded together with barcode information detected by the barcode reader 10 during information recording. And remaining tape information, and a battery (not shown)
And a random access memory (hereinafter referred to as SRAM) 15 backed up by
An on-screen display circuit (hereinafter referred to as OS) for displaying index information stored in the RAM 15
D) 16, video signal processing circuit 17 and monitor 18
And a microcomputer 1 for controlling the above system
1 is provided.

The operation of the above-described component VTR will be described below. FIG. 2 is a perspective view showing a state in which the cassette 1 is inserted into the VTR main body 20, and the magnetic tape 2, that is, a bar code 9 which is put on the side of the cassette 1 when the cassette 1 is inserted into the VTR, is a bar code. By reading with the reader 10, first, the microcomputer 11 recognizes which cassette has been inserted. That is, since the cassette 1 is marked with the bar code 9 encoding the cassette number, the cassette can be specified by decoding the bar code.

At the time of recording, the microcomputer 11 sends the cassette number, index information about the information to be recorded, and the remaining tape information at the start of recording to the SRA.
It is stored in M15. The index information is information whose contents such as recording date, recording start time, tuner channel number, and title can be recognized later. The tape remaining amount information is for storing where information to be recorded is recorded on the tape, and is obtained, for example, by measuring the rotation period of the S reel 4 and the rotation period of the T reel 5. For example, it is the remaining time of the tape from the recording start position to the end of the tape.

FIG. 3 is an enlarged view of a portion of the cassette 1 shown in FIG. 1. An embodiment of a method for detecting the remaining tape time of the microcomputer 11 will be described with reference to FIG. In FIG. 3, Vt is the traveling speed of the magnetic tape 2 [m /
s] and r are the hub radii [m] of the S reel 4 and the T reel 5, Rs and Rt are the radii [m] to the outer circumference of the magnetic tape wound on the S reel and the T reel, and Ss and St are S, respectively. Area [m2] including the magnetic tape 2 wound around the reel 4 and the T-reel 5 and the reel hub, ω
s and ωt are the rotational speeds [rad / s] of the S reel 4 and the T reel 5, respectively.

The angular velocities ωs and ωt can be obtained by measuring the period of the rotation speed detection signal detected by the S reel rotation speed detector 6 and the T reel rotation speed detector 7. Therefore, the radii Rs and Rt to the outer circumference of the magnetic tape wound on the S reel 4 and the T reel 5 are R
s = Vt / ωs and Rt = Vt / ωt. Therefore, it corresponds to the length of the magnetic tape 2 wound on the cassette 1.
The total area S of the tape including the reel hub is S = Ss + St =
π (Rs2 + Rt2). By the way, there are several types of lengths of the magnetic tape 2 wound around the cassette 1. For example, in the VHS standard described above, a 120-minute tape, a 90-minute tape,
There are 60-minute tape, 30-minute tape and the like. Therefore, the total area of the tapes S120, S90,
By obtaining S60 and S30, it is possible to detect how long the cassette 1 currently inserted in the VTR is a tape. Based on the result, the tape area Sso including the reel hub on the S reel side is obtained again. For example, if the detection result is a 120-minute tape, Sso becomes Sso = S120 × ωt2 / (ωs2
+ Ωt2). Then, the remaining tape amount L [m] can be calculated by dividing the net tape area excluding the area of the reel hub by the tape thickness τ [m], and the remaining tape time T [s] can be calculated by dividing this by the tape speed. That is, L = (Sso−
By calculating πr2) / τ, T = L / Vt, the remaining tape information can be obtained.

Further, the microcomputer 11 controls the control signal recording / reproducing circuit 1 shown in FIG.
2, a so-called VISS signal obtained by modulating a control signal with a duty ratio is recorded on the magnetic tape 2.

FIG. 4 shows a recording waveform of a control signal, a reproduction waveform, and a recording format of a cue signal for explaining a VISS search function for performing cueing by modulating a control signal with a duty ratio. When one cycle is 100%, a signal having a high level period of about 60% (FIG. 4A is a "0" pulse and a signal having a high level period of about 27.5% (FIG. 4B))
Is a "1" pulse, and a cueing code as shown in FIG. 4C is recorded at the start of the recording, that is, at the beginning of the program to be recorded. And at the time of VISS search,
The cueing code is detected by measuring the duty ratio of the reproduction control signal at the time of fast forward or rewind, and the mode is shifted to the reproduction mode.

The above operation is performed for each series of recording operations, that is, the cassette number, index information, and remaining tape information are stored in the SRAM 15 for each program (hereinafter, referred to as a program), and the cue signal is output. The information is recorded on the magnetic tape 2. Of course, if another cassette is inserted, the cassette number corresponding to the bar code marked on that cassette is stored.

FIG. 5 is a map diagram of cassette numbers, index information, and remaining tape information stored in the SRAM 15. The horizontal axis indicates the lower address (4 bits).
The vertical axis represents the space with the upper address (7 bits). Then, as shown by 151, 152 and 153 in FIG. 5, for each program to be recorded on the tape, 1 byte for the cassette number, 1 byte for the channel, 3 bytes for the recording date, 2 bytes for the recording start time, 2 bytes for recording end time, 2 bytes for remaining time at start of recording, 5 bytes for title, etc.
It is composed of 6 bytes. In the case of FIG. 5, the total memory capacity is 16K (16384) bits, and up to 128 programs can be stored.

By the way, VTR recording is roughly classified into normal recording and timer recording. In particular, in the case of timer recording, the timer microcomputer (not the time when the timer is reserved) is used when the time is up and the recording is actually started. Index information stored in the microcomputer 1 (not shown).
1 is received and written into the SRAM 15. In other words, this is to prevent a malfunction when a timer is reserved but not recorded for some reason.

A case where the tape recorded as described above is reproduced will be described below. First, when the cassette 1 is inserted into the VTR, the microcomputer 11 first checks which cassette has been inserted by reading the bar code 9 marked on the side surface of the cassette 1 by the bar code reader 10 in the same manner as during recording. . Then, the index information corresponding to the detected cassette number is read out from the SRAM 15 and is supplied to the video signal processing circuit 1 via the OSD circuit 16.
7 is displayed on the monitor 18 screen. FIG. 6 shows an example of the display. In this case, the cassette number inserted into the VTR is "5", and a total of five numbers (programs) are currently recorded on this tape. Is a 6-channel Western movie theater recorded at 9:00 pm on October 20, and the program of program number 2 is a 10-channel drama recorded at 7:00 pm on October 25. Then, after selecting a program number on the screen of the monitor 18 using the operation keys 14, V
When the TR is set to the reproduction mode, the microcomputer 11
After the program selected by the software program incorporated in the program is searched, the reproduction state is automatically set. When the cassette 1 is not inserted or when it is desired to search the contents of a cassette different from the inserted one, the cassette identification information is input by inputting the cassette identification information from the outside with the key input device 14 or the like. The index information is displayed on the monitor screen in the same manner as in FIG. 6, and if the cassette 1 is inserted after selecting the program, the program selected by the software program incorporated in the microcomputer 11 is searched, and then automatically. The playback state is set. The above operation will be described with reference to a flowchart of a software program incorporated in the microcomputer 11 shown in FIG.

First, at processing block 111,
The tape remaining amount is detected in the same manner as described for recording, and the current tape position is detected. Next branch 112
Detected during recording of the program selected in the SRAM 15
Time remaining in the tape and the processing block 111
Compares the current tape remaining time detected in
As a result, if the current position is 10 minutes or more before the target position, the processing shifts to processing block 113, where the VTR is set to the fast-forward (FF) state, and the current position is shifted by 10 to the target position.
If it is more than one minute later, the processing moves to processing block 114 and the VTR
In the rewind (REW) state, and the respective processing blocks 1
Return to 11. If the current position is within 10 minutes of the target position, the processing shifts to processing block 115, where the VTR is set to the above-described VISS search state, and when the start code of the selected program is detected, the processing block 116 sets the VTR to the reproduction mode. Complete a series of search operations. In other words, the position where the program is recorded is roughly detected by the remaining tape amount detection function, and finally the position is detected with high accuracy by the VISS search function.

As described above, according to the video tape recorder of the embodiment of the present invention, at the time of recording, a cassette is specified by a bar code, index information such as cassette number, date, time, channel title, etc., and each program recording The position information is stored in SRAM, and VIS is added to the beginning of each program on the tape.
The S signal is recorded, the cassette is identified by a barcode at the time of reproduction, and the corresponding index information is stored in the SRA.
Read from M and display on monitor. When the desired playback program number is input from the key input device, the current position of the tape is
It is compared with the head position of the desired program recorded in the AM, and F
The head position is roughly moved to the vicinity of the reproduction start position by the F or REW operation, and finally the desired program selected by the VISS search is arranged so as to be accurately searched. The desired program can be automatically and promptly reproduced by key input.

In the case of over-recording on a recorded tape, the microcomputer 11 records the remaining tape time at the start of recording and the recording end time of over-recorded programs among all programs registered under the cassette number. By erasing all index information and remaining tape information of a program having a remaining tape time during the remaining tape time at the time of the search, it is possible to prevent a search from malfunctioning and to reduce the
Can be used more efficiently.

In general, a VTR has a plurality of recording time modes, but the above-described remaining tape detection time is converted into a long time recording mode in any recording time mode to prevent a malfunction in retrieval. be able to.

During or after recording, the SRAM 1
By inputting audio switching data into the index information on the top 5, it is possible to automatically reproduce a desired sound at the time of reproduction. For example, in the case of bilingual broadcasting such as a Western movie, the main recording is performed at the time of recording. If audio (Japanese) playback is specified, it will automatically be played back in Japanese during playback.

At the time of the program search and reproduction described above, the reproduction completed flag set in the index information in the SRAM 15 corresponding to the program is set, and when the recorded program is displayed as shown in FIG. By displaying the mark (not shown), when the same cassette is inserted later, an unplayed program can be seen at a glance, and it is also easy to realize that a recorded program can be prevented from being forgotten or mistakenly deleted. is there.

During or after recording, the SRAM 1
5 by setting the reproduction inhibition flag set in the index information above and simultaneously inputting a password, thereby prohibiting the above-described program search operation, and enabling a program search by inputting a password. It is also possible to protect recorded programs.

Further, it is also possible to easily realize a program reproduction in which a plurality of program numbers are selected at the time of program selection at the time of reproduction and a program is reproduced in a series.

Further, since the total recording time of all programs recorded on a certain tape can be calculated from the data stored in the SRAM 15, the remaining recordable time is determined before the start of the next recording by the result of the tape type discrimination of the remaining tape amount detection. Can be displayed on the monitor screen.

[0032]

As described above, the present invention has an excellent effect that it is possible to provide a video tape recorder capable of displaying the remaining tape time for each of a plurality of types of recording modes.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video tape recorder according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing a state where the cassette is inserted into the VTR main body according to the first embodiment.

FIG. 3 is an enlarged view of a cassette part according to the first embodiment.

FIG. 4 is a recording format diagram of a control signal recording waveform, a reproduction waveform, and a cue signal for explaining a VISS search function according to the first embodiment;

FIG. 5 is a map diagram of cassette numbers, index information, and remaining tape information recorded in an SRAM according to the first embodiment;

FIG. 6 is a schematic diagram of a monitor screen display example according to the first embodiment.

FIG. 7 is a flowchart of a software program incorporated in the microcomputer according to the first embodiment.

[Explanation of symbols]

 Reference Signs List 1 cassette 2 magnetic tape 4 supply reel 5 take-up reel 6 supply-side reel rotation speed detector 7 take-up reel rotation speed detector 8 control head 9 barcode 10 barcode reader 11 microcomputer 12 control signal recording / reproducing circuit 13 Tape Drive Circuit 14 Key Input Device 15 SRAM 16 On-Screen Display Circuit 17 Video Signal Processing Circuit 18 Monitor

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Koji Takebayashi 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A video tape recorder capable of programming and recording a program in a plurality of types of recording modes for a plurality of types of cassettes having different tape lengths, comprising: a tape type detection unit for detecting the tape lengths of the plurality of types of cassettes; A tape remaining time detecting unit for detecting a remaining tape time for each of a plurality of types of recording modes based on the tape length of the cassette obtained by the tape type detecting unit. Video tape recorder that can display time. 2. The video tape recorder according to claim 1, wherein the tape type detecting unit detects the tape type based on an output of the tape speed detecting unit, an output of the S reel rotational speed detecting unit, and an output of the T reel rotational speed detecting unit. . 3. A tape remaining time detecting section, which outputs a tape speed based on an output of a tape speed detecting section, an output of an S reel rotational speed detecting section, an output of a T reel rotational speed detecting section, tape thickness information and hub diameter information. 2. The video tape recorder according to claim 1, wherein the video tape recorder detects a remaining tape time for a plurality of recording time modes different from each other. 4. The video tape recorder according to claim 1, further comprising a display unit for displaying a remaining tape time for each of a plurality of types of recording modes. 5. The video tape recorder according to claim 1, wherein the remaining tape time can be displayed before starting recording.