JP2924330B2 - Video tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder (hereinafter, abbreviated as "VTR") having a recording / reproducing function, and is particularly effective for retrieving information recorded on a magnetic tape. It dramatically improves the performance.

[0002]

2. Description of the Related Art In a conventional VTR, as a first means for retrieving recorded information, there is a method in which a servo control signal is duty-modulated at the beginning of information to be taken out from a magnetic tape to record a cue signal. . VHS standard V which is the mainstream of so-called home 1/2 inch VTR
This is called an ISS search function, which detects a cue signal (VISS signal) in a fast forward / rewind (hereinafter abbreviated as FF / REW) state and shifts to a stop state or a reproduction state. A 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 a magnetic tape is obtained. If it is, it is shifted to the stop or playback state.

[0003]

As a problem in the above-described method of searching for the beginning of recorded information, first, when recording the next program on a tape that has been recorded once but has not been reproduced, it is instantaneous where to record it. Since it is not clear, it was necessary to reproduce the tape and find the recording end position to avoid erroneous erasure.

When searching for information recorded on a magnetic tape, first, in any case, since the current absolute position of the magnetic tape is unknown, it is necessary to start winding the magnetic tape before searching. There is a problem that the information to be searched cannot be obtained quickly. Second,
Store index information such as titles and count values in the case of the counter search function so that you do not forget what was recorded on the magnetic tape, or put it on a label etc. and attach it to the cassette that stores the magnetic tape Need to be kept. Furthermore, in order to avoid forgetting to read or erroneously erasing the information recorded for the above reasons, only one piece of information is often recorded on one tape, which has reduced the use efficiency of the tape.

[0005]

In order to solve the above-mentioned problems, a video tape recorder according to the present invention comprises: an information obtaining means for inputting or collecting index information relating to information to be recorded; and a detecting means for detecting a winding position of the tape. A tape position detecting means, a memory means for storing index information obtained by the information obtaining means and a tape position information obtained by the tape position detecting means, an information input / output means for inputting / reading information to / from the memory means, A cue signal recording means for recording a cue signal indicating a recording start position on a tape; and a cue signal detection means for detecting the cue signal when reproducing, fast-forwarding or rewinding. In normal recording or timer recording, the index information of the program obtained by the information acquisition means and the tape position The tape position information at the start of recording obtained by the detection means is stored in the memory means by the information input / output means, and the program designated by the user by the information input / output means by the index information read from the memory means at the time of reproduction. When searching for the beginning of the program, if the beginning of the program is closer to the end of the tape than the current tape winding position, the tape position at the start of recording of the program read from the memory means by the information input / output means By comparing and calculating the information and the current tape position information obtained by the tape position detecting means, the position at which the recording position of the cue signal recorded by the cue signal recording means, which is the start position of the program, has passed to the end side. After fast-forwarding to
The cue signal detection means performs rewinding until the cue signal recording means detects the cue signal recorded.If the beginning of the program is closer to the beginning of the tape than the current tape winding position, information is read from the memory means. By comparing and calculating the tape position information at the start of recording of the program read by the input / output means and the current tape position information obtained by the tape position detection means, the cue signal recording means, which is the program start position, After rewinding the recorded cue signal recording position to the position where it has passed to the start end side, the cue signal detection means fast-forwards until the cue signal recording means detects the cue signal recorded. Automatically search for the beginning of.

In the case where the start position of the program is closer to the end of the tape than the current tape winding position, the end of the tape is reached while fast-forwarding to the position where the recording position of the cue signal has been passed to the end. In this case, the cue signal detecting means rewinds from the end of the tape until the cue signal recording means detects the cue signal recorded, and the program start position is closer to the beginning of the tape than the current tape winding position. In some cases, the search operation is terminated at the beginning of the tape when it reaches the beginning of the tape in the middle of fast-forwarding to the position passing the recording position of the cue signal to the beginning.

[0007]

According to the present invention, with the above-described structure, the conventional V
In order to improve the function of searching for the beginning of a recorded program, which is a major problem of the TR and could not satisfy the user even though some functions were proposed, the VTR was previously set by the VTR at the time of program recording. If index information indicating the prepared program contents is added as program information, the user automatically selects and specifies the program to be reproduced based on the information at the time of reproduction, and the beginning of the program is automatically searched. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a video tape recorder according to an embodiment of the present invention. The cassette 1 stores a magnetic tape 2 and a rotary head (not shown) that records and reproduces information on the magnetic tape 2. A rotating drum 3 to be driven, and a supply-side reel (hereinafter abbreviated as S reel) 4 for sending out the magnetic tape 2 at the time of reproduction or FF / REW.
A take-up reel (hereinafter, abbreviated as a T reel) 5 that winds the magnetic tape 2 at the time of reproduction or FF / REW.
A control head 8 for recording and reproducing servo control signals; a control signal recording / reproducing circuit 10 for writing / reading a cue signal to / from the magnetic tape 2 via the control head 8; an FF / REW state and a reproduction state of the VTR A tape drive circuit 12 for driving a capstan motor (not shown) or a reel motor (not shown) to transfer the magnetic tape 2 in accordance with the condition, and a key input device such as timer reservation or VTR operation. A remote control device 16, a static random access memory (hereinafter abbreviated as SRAM) 11, which stores index information and remaining tape information relating to a program to be recorded and which is backed up by a battery (not shown) in the event of a power outage, when necessary. The index information stored in the SRAM 11 is Oz screen display (hereinafter abbreviated as OSD circuit.) For Shimesuru is entirely composed of the 15 and the video signal processing circuit 14 and a monitor 13, a microcomputer 9 for controlling the above systems.

The operation of the VTR constructed as described above will be described in detail below. At the time of recording, the microcomputer 9 causes the SRAM 11 to store index information on information to be recorded and remaining tape information at the start of recording. The index information includes a recording date, a recording start / end time, a channel number of a tuner, and a program title.

The title of the program is stored in the ROM of the microcomputer 9 so that the contents of information to be stored such as keywords most suitable for the program can be recognized later. Here, the keyword of the program is a keyword that has been selected in advance and indicates to which field the program belongs, such as manga, news, comedy,
Such as suspense.

Further, information relating to recording may be stored for each cassette, and a cassette number may be added as index information for recording in order to improve operability of retrieval. As a means for inputting a cassette number, a method of inputting the cassette number by a user using the key input device 16 or the cassette number is automatically recognized by the VTR itself. For example, a method is conceivable in which a bar code label indicating a cassette number attached to a cassette is read by a bar code sensor attached to the VTR body when the cassette is inserted.

The tape remaining amount information is used to store where information to be recorded is recorded on the tape. 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. 2 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 9 will be described in detail with reference to FIG. In FIG. 2, Vt is the traveling speed of the magnetic tape 2 [m
/ S], r is the hub diameter [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 4 and the T reel 5, respectively.
Ss and St are the area [m ² ] including the magnetic tape and the reel hub wound on the S reel and the T reel, respectively.
ωs and ωt are the rotational angular velocities [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. Accordingly, 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 determined.
Is determined by the following equation.

[0015]

(Equation 1)

[0016]

(Equation 2)

Therefore, the total area S of the tape including the reel hub, which corresponds to the length of the magnetic tape wound on the cassette, is expressed by the following equation.

[0018]

(Equation 3)

By the way, there are several types of the length of the magnetic tape wound on the cassette 1.
In the S standard, there are 120 minutes tape, 90 minutes tape, 60 tapes, 30 minutes tape, and the like. Therefore, the total area of each tape S ₁₂₀ , S ₉₀ , S ₆₀ , S
If you ask for ₃₀ , the cassette 1 that is inserted in the VTR now
Can detect how many minutes the tape is. Based on the result, the tape area S again including the reel hub on the S reel side
So is obtained. For example, if the detection result is a 120-minute tape, Sso is expressed by the following equation.

[0020]

(Equation 4)

The remaining tape length L [m] is obtained 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] by dividing this by the tape speed. Can be calculated. That is,

[0022]

(Equation 5)

[0023]

(Equation 6)

The remaining tape information is calculated by calculating Further, the microcomputer 9 starts the control signal recording / reproducing circuit 1 of FIG.
The start signal, the so-called VISS signal, obtained by duty-modulating the control signal with 0, is recorded on the magnetic tape 2.

FIG. 3 shows a recording waveform and a reproduction waveform of the control signal and a recording format of the cue signal for explaining a VISS search function for performing cueing by duty-modulating the control signal. When one cycle is set to 100%, a signal (FIG. 3A) in which a high level (hereinafter abbreviated as H level) period is approximately 60% is a “0” pulse, and an H level period is approximately 27.5%. Signal (FIG. 3B) is a "1" pulse,
At the start of the recording, that is, at the beginning of the program to be recorded, FIG.
A cueing code as shown in (C) is recorded. At the time of the VISS search, the cue code is detected by measuring the duty of the reproduction control signal at the time of FF or REW, and the operation for shifting to the reproduction mode is performed for each series of recording operations. The cassette number index information and the remaining tape information are stored in the SRAM for each program, and a cue signal is recorded on a magnetic tape. Of course, if another cassette is inserted, the cassette number corresponding to that cassette is stored.

FIG. 4 is a map diagram of cassette numbers, index information, and remaining tape information stored in the SRAM. 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 01, 02 and 03 in FIG. 4, 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, and 2 bytes for the recording start time Two bytes are used for the end time, two bytes are used for the remaining time at the start of recording, and five bytes are used for the program title. The total is 16 bytes per program. In the case of FIG. 4, the total memory capacity is 16K (1638).
4) Bits, capable of storing up to 128 programs.

A method of storing index information in the SRAM with the above configuration in a case of normal recording will be described.

When the VTR enters the recording mode, the microcomputer 9 controls the OSD circuit 15 to display the keywords stored in the ROM of the microcomputer on the monitor 13. (Not shown.) The keyword group displayed at this time represents a general program field such as manga, news, comedy, and suspense. When such a display appears, the user selects a keyword most suitable for the program to be recorded by the key input device 16 and presses a key (not shown) indicating the end of the selection. The index information such as the cassette number and the recording date and the remaining tape information at the recording start position are stored in the SRAM 11 together with the keyword selected by the user according to the memory map in FIG.

Next, a search method at the time of reproducing the program thus recorded will be described. When the user presses a key (not shown) indicating a search mode provided on the key input device 16 during reproduction, the microcomputer 9
Controls the OSD circuit 15 to display the screen of FIG. The content displayed at this time is the index information of the program for each cassette. Then, when the user selects a program to be reproduced from the programs displayed in FIG. 5 and inserts a cassette of a corresponding number, the microcomputer 9 executes the tape based on the tape remaining amount information stored in the SRAM 11. By controlling the drive circuit 12, the head of the selected program is searched to start reproduction.

The above-described method of searching for the beginning of a program will be described in detail with reference to a tape running diagram shown in FIG.

In FIG. 6, reference numeral 17 denotes a model from the beginning to the end of the tape, 18 denotes a locus indicating the running direction of the tape, A denotes the current winding position of the tape, B denotes the recording start position of the program, The shaded portion of B is a VISS signal written by the control signal recording / reproducing device 10. First, in (a) to (d), the microcomputer 9 detects the position A, that is, the current tape winding position, by the above-described remaining tape time detection method. Next, the position of B, that is, the remaining time of the tape detected in recording the selected program and stored in the SRAM and A
Is compared with the remaining tape time at the position, and the search direction at the beginning of the selected program is determined based on the result. That is, it is determined whether the current position is on the start end side or the end side with respect to the target position. The operation in each case will be described below.

First, (a) shows a search method in the case where the current position is on the start end side with respect to the beginning of the program. When the microcomputer 9 determines that the position A is on the starting end side with respect to the position B, it sends a command to the tape drive circuit 12 to bring the VTR into the fast-forward FF state. During this time, the microcomputer 9
Performs a comparison of the position of B, that is, the time remaining when the selected program is recorded, and compares the remaining tape time stored in the SRAM 11 with the current remaining tape time. When the tape winding position reaches the position C beyond the position B, a command is sent to the tape drive circuit 12 to stop the VTR. Next, the microcomputer 9 sets the VTR to the REW state, performs a VISS search, and when the control signal recording / reproducing apparatus 10 detects the VISS signal of the selected program, the VT
R is set to the playback mode, and a series of search operations are completed. That is, the position where the program is recorded is roughly detected by the tape remaining amount detection function, and then detected with high accuracy by the VISS search function.

Here, the VISS search in the REW mode in the reverse direction after passing once through the position B in the FF state is performed by first stopping at the position where the VISS signal is written, and
This is because there is a problem that a VISS signal to be searched cannot be found when entering the S search. Second, the VTR is temporarily stopped a certain distance before the position B, and the VIS is stopped in the FF state.
A method of moving to the S search is also conceivable, but it is very difficult to realize it. If the vehicle stops at the position passing the position B by mistake, it passes the position where the VISS signal to be searched is written. This is because there is a problem that the beginning of the program cannot be found even if the program is continued. This is because, in a general VTR, the FF or REW drives the S reel and T reel to feed the tape instead of transporting the tape at a constant speed by the capstan. Vt is not constant, and the distance traveled by the tape from the output of the stop command from the microcomputer 9 to the actual stop of the VTR fluctuates, and the tape stops or passes shortly before the position B. Of course, if the microcomputer 9 outputs the stop command at a timing sufficiently shorter than the position B in consideration of the variation of Vt, the position of the position B can be surely determined. Although it is possible to stop at the foreground, it takes time for the VISS search, or the VISS signal is Control signal recording and reproducing apparatus 10 When you have him
Determines that the VISS signal has reached the beginning of the selected program, and causes a search error. Third, a VISS search is temporarily stopped at a position beyond the position B, and a VISS search is performed in a direction opposite to the direction in which the tape has been transported.
This is because performing the WISS search in the W direction has the advantage that the VISS signal can be reliably searched for even if the stop position slightly changes due to various factors. As a method for the microcomputer 9 to stop the VTR at the position C which is beyond the position B, the position of the B, that is, the remaining time of the tape detected at the time of recording the selected program and stored in the SRAM 11 and the current remaining time of the tape are The VTR is stopped after a certain period of time after the data match, or
A certain distance from the data stored in the RAM, for example, 5
A method of temporarily holding the value shifted to the minute end side as the remaining tape time at the position C, comparing it with the current remaining tape time, and stopping the VTR when the data match with each other can be considered. In the former method, the tape speed Vt changes depending on the winding position of the tape and the distance between B and C varies, but in the latter method, the microcomputer 9 stops during FF because the remaining tape time is used. Although the distance traveled by the tape until the VTR reaches the stop state after outputting the command changes slightly depending on the winding position of the tape,
The tape can be stopped at a substantially constant position C from B. The distance between B and C must be sufficiently large as long as the VISS signal at the beginning of the selected program can be detected.
In order to complete the VISS search in a short time, it is desirable to be as short as possible.

Next, referring to FIG. 6 (b), a description will be given of a search method when the current position is on the end side with respect to the beginning of the program. When the microcomputer 9 determines that the position of A is on the end side with respect to the position of B, it sends a command to the tape drive circuit 12 to rewind the VTR to bring it into the REW state. During this time, the microcomputer 9 compares the remaining tape time stored in the SRAM 11 with the current tape remaining time detected at the position of B, that is, when the selected program is recorded. When the tape winding position reaches the position C beyond the position B, a command is sent to the tape drive circuit 12 to stop the VTR. Next, the microcomputer 9 sets the VT
A VISS search is performed with R in the FF state, and when the control signal recording / reproducing apparatus 10 detects the VISS signal of the selected program, the VTR is set to the reproduction mode, and a series of search operations is completed.

Next, referring to FIG. 6C, when the start position of the program is closer to the end of the tape than the current tape winding position, the program is fast-forwarded to the position where the recording position of the cue signal has passed to the end. When the microcomputer 9 judges that the position of A is on the start end side with respect to the position of B when the end of the tape is reached halfway through, the microcomputer 9 sends a command to the tape drive circuit 12 to fast-forward the VTR to the FF state. And At this time, if the above-described method of determining the position C by shifting the remaining tape time at the position B by a fixed amount of 5 minutes is used as a method for determining the position C that has passed the position B, from the position B to the end D Is less than 5 minutes, the microcomputer 9 detects that the tape winding position has reached the end D, not the position C that does not actually exist,
A command is sent to the tape drive circuit 12 to stop the VTR.
Next, the VTR is set to the REW state and a VISS search is performed.
When the control signal recording / reproducing device 10 detects the VISS signal of the selected program, the VTR is set to the reproduction mode, and a series of search operations is completed.

Finally, referring to FIG. 6D, when the start position of the program is closer to the beginning of the tape than the current tape winding position, the program is fast-forwarded to a position where the recording position of the cue signal has passed to the beginning. A search method when the start end of the tape is reached during the recording will be described. When the microcomputer 9 determines that the position A is on the end side with respect to the position B, it sends a command to the tape drive circuit 12 to rewind the VTR and
EW state. At this time, according to the method of determining the position C at which the tape remaining time at the position B is shifted by a fixed amount of 5 minutes to determine the position C as the method of determining the position C that has passed the position B, the position C actually exists. However, the microcomputer 9 compares the position of B, ie, the remaining time of the tape detected at the time of recording the selected program and stored in the SRAM 11, with the current remaining time of the tape, and
At the same time, it also detects whether the tape winding position has reached the start end D. Of course, the microcomputer 9 detects that the winding position of the tape has reached the start end D, and sends a command to the tape drive circuit 12 to stop the VTR. Next, the VTR is set to the reproduction mode, and a series of search operations is completed. At this time, V
The reason why the TR is not set to the VISS search mode in the FF state is
First, the distance from the start point D to the start position B of the program is as short as 5 minutes or less. Second, the VISS signal is written at the start point D.
That is, when the control signal recording / reproducing apparatus 10 cannot detect the VISS signal when the beginning of the program is at the beginning D, it is possible to avoid a problem that the beginning of the program cannot be found even if the VISS search is continued.

In general, a VTR has a plurality of recording time modes. However, the above-mentioned remaining tape detection time is converted into a long time recording mode regardless of the recording time mode, thereby preventing a search malfunction. Is being planned.

[0038]

As is apparent from the above description, the video tape recorder of the present invention can accurately perform the method of searching for a recorded program, which has conventionally been the biggest problem of a VTR, without performing complicated operations. By such an improvement, the operability is drastically improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a video tape recorder of the present invention.

FIG. 2 is an enlarged view of a cassette part of the embodiment.

FIG. 3 is a recording format diagram of a control signal recording waveform, a reproduction waveform, and a cue signal for explaining a VISS search function of the embodiment.

FIG. 4 is a map diagram of cassette numbers, index information, and remaining tape information stored in the SRAM of the embodiment.

FIG. 5 is a monitor screen display example of cassette-based program index information according to the embodiment;

FIG. 6 is a schematic diagram showing an example of a running operation of a tape during a program search according to the embodiment;

[Explanation of symbols]

 Reference Signs List 1 cassette 2 magnetic tape 3 rotating drum 4 supply reel 5 take-up reel 6 supply reel rotation speed detector 7 take-up reel rotation speed detector 8 control head 9 microcomputer 10 control signal recording / reproducing device 11 SRAM memory 12 Tape drive circuit 13 Monitor 14 Video signal processing circuit 15 On-screen display circuit 16 Key input device 17 Magnetic tape 18 Tape running locus

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 5/782 Z G11B 27/28 A 27/17 C (72) Inventor Yoshikazu Kageyama 1006 Kazuma, Kazuma-shi, Osaka Matsushita Electric Sangyo Co., Ltd. (58) Surveyed fields (Int.Cl. ⁶ , DB name) G11B 27/28 G11B 15/02 310 G11B 15/087 101 G11B 27/17 H04N 5/7826

Claims (2)

(57) [Claims] 1. A video tape recorder having a recording / playback function, comprising: information acquisition means for inputting or collecting index information relating to information to be recorded; tape position detection means for detecting a winding position of a tape; Memory means for storing index information obtained by the information obtaining means and tape position information obtained by the tape position detecting means; information input / output means for inputting / reading information to / from the memory means; A cue signal recording means for recording a cue signal indicating a position on a tape; and a cue signal detection means for detecting the cue signal when reproducing, fast-forwarding, or rewinding. At the time of scheduled recording, the program index information obtained by the information obtaining means and the tape position detecting means The information input / output means stores the tape position information at the start of recording in the memory means, and at the time of reproduction, the user designates the tape position information by the information input / output means using the index information read from the memory means. When searching for the beginning of the program, the recording of the program read by the information input / output means from the memory means when the beginning of the program is closer to the end of the tape than the current tape winding position. By comparing and calculating the tape position information at the start and the current tape position information obtained by the tape position detection means, the recording of the cue signal recorded by the cue signal recording means, which is the start position of the program, is performed. After fast-forwarding to a position where the position has passed to the terminal side, the cue signal detecting means records the cue signal recording means. The program is rewound until a cue signal is detected, and when the beginning of the program is closer to the beginning of the tape than the current tape winding position, the program read from the memory means by the information input / output means is read. By comparing and calculating the tape position information at the start of recording and the current tape position information obtained by the tape position detecting means, the cue signal recorded by the cue signal recording means, which is the start position of the program, After rewinding to the position where the recording position of the program has passed to the start end side, the cue signal detection means performs fast forward until the cue signal recording means detects the cue signal recorded. A video tape recorder characterized by a dynamic search. 2. When the start position of a program is closer to the end of the tape than the current tape winding position, the program ends at the end of the tape while fast-forwarding the recording position of the cue signal to the end. When it reaches, from the end of the tape, the cue signal detection means performs rewind until the cue signal recorded by the cue signal recording means is detected,
If the start position of the program is closer to the beginning of the tape than the current tape winding position, and if the tape reaches the beginning of the tape while fast-forwarding to the position passing the recording position of the cue signal to the beginning, 2. The video tape recorder according to claim 1, wherein the search operation ends at a start end.