JPS6310390A - Tape remainder display device - Google Patents

Abstract

PURPOSE:To display a tape remainder by fast forwarding and rewinding a tape cassette through the operation of a tape remainder display switch just after the cassette is loaded onto a VTR. CONSTITUTION:When the type of tape cassette is automatically discriminated, a switch 17 is used as a one to specify the types (T-120 and T-160) of tape cassettes that cannot be discriminated. Just after the tape cassette is loaded onto the VTR, the types of tape cassettes that can be specified through the switch 17 are fast forwarded(FF) or rewound (REW), thereby calculating the tape remainder time. Thus the time is displayed as a 1st display state. After a known VTR action at a constant tape speed, the remaining times of all types of tape cassettes can be displayed as 2nd display states.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a tape remaining amount display device for displaying the remaining amount of time of a tape cassette loaded in a magnetic recording/reproducing apparatus (VTR).

(b) Conventional technology Generally speaking, as with video tape recorders (VTRs), audio decks, and cassette decks, when information (including video signals and audio signals) is to be recorded on a magnetic tape, only the part of the recorded information is recorded. In order to continue recording new information, it is necessary to know the remaining amount of tape. That is, if it is a new blank cassette, for example V
In the H8 system, like T-120, T-160, etc., the recordable time is displayed on the cassette, and the S
While the user can determine the amount according to P and EP, it is necessary to know the remaining amount when additionally recording on the recorded cassette.

As an example, Japanese Patent Application Laid-Open No. 59-198581 discloses that the remaining amount time T is measured using known tape speed v1 tape thickness a1 supply reel hub diameter r, and the rotation period t of the supply reel and the rotation period of the supply reel. A technique is shown in which the tape speed is measured and calculated using the following equation.

(c) Problems to be solved by the invention In the case of the conventional example, FF (fast forward) and REW (rewind)
Although it has the advantage of being able to calculate the remaining amount of tape even in VTR operating conditions where the tape running speed is unknown, this method only measures the reel rotation period on the supply side.
Although the detection mechanism is simple, since the entire equation (A) is divided by the tape thickness (a), the calculated remaining amount error due to the tolerance of the tape thickness (a) is large.

Therefore, as an indication of the remaining amount of time, a digital display, that is, 1-1
It is difficult to display "0 minutes", and it is necessary to use a bar graph method using display elements such as LEDs provided in units of 10 minutes or 30 minutes, for example. In addition, in the case of the VH8 system, some types of tape cassettes have different tape thickness a and reel hub diameter r, which must be known in the calculation formula, and these can be specified by the user using a switch, etc. Must be taken away. Generally, this designation is given by the name of the tape cassette so that it is easy for the user to understand. Types of tape cassettes include T-20, T-60, T-90, T-120, and T-1.
There are 60, and the switch positions are T-20 to T-
Considering the case where three positions are set: 60 to T-90, T-120, and T-160, T-20 to T-60 to T-90 = -a -20 (μ) , r= 31 (11
11) T-120=a-20(μ), r=13 (I
TIn)T-160-a-15,6(μ), r=1
3 (11111).

Therefore, the three positions of the above switch, especially T-120,
The T-160 had the disadvantage that it included not only tape thickness and hub diameter but also all parameters of the tape cassette as information, and the method of using this information was quite complicated.

The present invention provides a novel tape remaining amount display device that eliminates the above-mentioned drawbacks.

(d) Means for Solving the Problems The present invention provides a supply reel and a take-up reel for transporting the tape in the cassette after the tape cassette is installed, and a first and second reel coupled to the two reels, respectively. rotation detection means;
an information processing unit connected to the output terminals of the first and second rotation detection means, a system control unit that performs various mode selection and control, and connected to the information processing unit, a remaining amount display switch, and a display. The remaining tape amount calculated by the information processing section is displayed on the display section according to the position of the changeover switch, and the remaining tape amount calculated by the information processing section is displayed on the display section, and the playback and recording information is displayed on the system control section. ,
Alternatively, when a control signal corresponding to a constant cheap speed mode corresponding to special playback is applied, the information processing section determines the type of the tape cassette and displays the tape assembly time on the display section. .

(*) Effect The present invention, after loading a cassette into a video tape recorder, immediately displays the remaining amount of tape on a display device in advance by fast forwarding or rewinding based on information corresponding to the tape type setting switch, and plays the tape. , recording or special playback, etc., VTR
When the operation mode becomes an operation mode in which the tape speed is known and constant, the type of the cassette can be automatically determined according to the operation mode, and the remaining tape time can be displayed.

(f) Embodiments To explain the present invention according to drawings, FIG. 1 is a block diagram showing a remaining tape amount display device of the present invention, FIG. 2 is a plan view of main parts of a tape cassette, and FIGS. 3 and 4 are FIG. 5 is a flowchart for explaining the device, FIG. 5 is a distribution diagram of parameters used in the device, and FIG. 6 is a display state diagram of the device. In the drawings, (1) is a tape cassette containing a magnetic tape (2), (3) is a supply reel with a supply reel hub (4), (5) is a take-up reel with a take-up reel stand (6), ( 7) is a pinch roller, (8) is a capstan, (9) is a supply reel, (10) is a take-up reel, (1
1) (12) are rotary plates attached to the supply reel shaft and take-up reel shaft, respectively; (13) and (14) are photo sensors for detecting the rotation of each reel provided corresponding to the rotary plates; (1)
5) is an information processing unit including a microcomputer, (16
) is the remaining amount display switch, (17) is the changeover switch for changing the cassette type, (is) is the display section that shows the tape remaining amount time, and (19) is the system control called system control (abbreviated as system control). Section (20) shows a switch group including switches for various operations.

Generally, the remaining tape amount T is 1 π from the perspective of the supply side.
(R,”−r,suT=□・□(see)...■ υ, μ.

Viewed from the take-up side, t, υ, where R, = 2□ ・・・・・・・・・・・・・・・
・・・・・・・・・・・・■t, υ.

R・-, □ ・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・Represented by ■.

In the above formula, υ. : Tape speed (m/see) for which the remaining amount is measured
) R6: Tape radius of supply reel (3) Cm) r,:
Hub radius of supply reel (3) (m) μ6: Tape thickness of supply reel (3) (m) L: Total tape length
(m) R8: Tape diameter radius of take-up reel (5) (m) rl: Hub radius of take-up reel (5) [m] μt: Tape thickness of take-up reel (5)
(m)t,: Reel rotation period (s) of supply reel (3)
ee) υ,: Tape speed (m/
see) t, rotation period of reel (5) with two turns [Sec] The above r indicates the leader tape thickness, and μ includes the air layer. The remaining time T mentioned above is the tape speed SP during recording and playback,
This is the time to the end of the tape when the tape runs at either LP or EP tape speed, and this tape speed is the tape speed that is the target of the remaining amount. shall be. Also, the reel cycle is measured to calculate the remaining amount of time.

Also, when measuring tl and it necessary for calculating R1 and R, a certain tape speed is required for convenience, and this tape speed is used as the tape speed υ when measuring the reel cycle.

shall be.

From the above formula 〇, ■ t, υ.

T=-(<2□>*-r, *)...
...■′υ, μ.

From formula ■, ■・・・・・・・・・・・・・・・・・・・・・
...If you eliminate υ1 from ■゛■゛ and ■′, you get 2π υ, μ6 υ. = ("7 houses (, T + rs") ・・・■Formula■■
′ and find T. Here μ, = μ1, K + = K 1 = K.

By measuring the constants in each of the above equations, the remaining amount time T can be determined.

Next, to explain the operation of the tape remaining amount display device of the present invention, in FIGS. seek. A supply reel (9) and a take-up tape reel (10) in the cassette (1) are coupled to a supply reel stand (4) and a take-up reel stand (6), respectively.

In the initial state, that is, before the VTR enters a well-known operating mode with a constant tape running speed, the tape type setting changeover switch (17) is used as a switch for specifying the type of tape cassette (1). (17)
If the type of tape cassette cannot be automatically determined, for example, for VH8 video cassettes, T-12
0, T-160 are included as positions, and although the example in FIG. 1 shows an example of three positions, it is also possible to add the T-30 position to make four positions.

Therefore, before the VTR goes through a well-known operation mode with a constant tape speed, the type of tape cassette is designated by the tape type changeover switch (17).

Next, when the tape speed is constant and the operation mode is known, the above-mentioned automatic tape cassette type discrimination operation is executed, but at that time, the switch (17) is activated to switch the tape cassette type that cannot be determined (the above-mentioned T-120 and T-1
60) can be used as a switch to specify.

Therefore, even immediately after the tape cassette (1) is installed in the VTR, the types of tape cassettes that can be specified by the switch (17) (especially the types that are likely to be used frequently by the user) are , for example, by fast forwarding (FF) or rewinding (REV), the remaining tape time can be calculated, which is displayed as the first display state, and the tape speed is constant and the VTR operation mode is well-known. After that, the remaining amount time can be displayed in the second display state for all types of tape cassettes.

Next, the main loop will be explained according to the flowcharts in FIGS. 3(a) and 3(b). First, the information processing unit (15)
Check the information from the system control unit (19) to see if the tape cassette has been installed in R. If it is not installed, the data indicating the remaining tape time will be cleared and at the same time the display (
18) is also cleared. This also applies when the tape cassette is ejected while the remaining tape time is being displayed. After that, this loop continues until the tape cassette is loaded again, and even if the tape cassette is loaded, the previous remaining amount data will not be restored.

When the tape force set 1-(1) is fully installed, the information processing section (
15) receives this as a signal from the system control unit (19), and at the same time confirms whether or not the tape is running. When the tape is running, the rotation cycles of both reels on the supply side and take-up side are controlled by the rotating plate (11) (12) and the sensor (13).
) (14) is determined based on the signal obtained from (14). If the measurement of both reels is known and the tape running speed is constant, then the rotation periods of both reels on the supply side and take-up side are measured.

The system control unit (19) also checks whether the measurement of both reels was carried out at a known and constant tape running speed.
If so, the type of tape cassette is automatically determined (described later). These are displayed even if the user has not instructed the remaining amount to be displayed, and therefore the remaining tape time (or "C" or "C"
ALC" is not displayed (for example, the tape counter is being displayed).

When the information processing unit (15) completes the measurement of the reel cycle, it calculates the remaining tape time, but the method for obtaining the necessary tape cassette parameters at this time is based on the fact that automatic tape cassette identification (described later) has already been completed. Depends on whether or not. The information processing unit (15) knows the parameter from the state of the changeover switch (17) before the automatic determination is executed, and conversely, the information processing unit (15) knows the parameter from the result if it is after the automatic determination. Furthermore, once the automatic discrimination of the tape cassette is executed, the result of the automatic discrimination is held in the information processing section (15) until the tape cassette is taken out (ejected).

Therefore, once the automatic discrimination is executed, even if the tape running speed is known and the VTR is not operating at a constant rate,
It is possible to display the remaining amount of all tape cassettes that are not present in the tape cassette type changeover switch.

The measurement results of the rotation period of both reels (3) and (5) on the supply side and take-up side are also the same, and once the tape runs and the measurement of the rotation period of both reels (3) and (5) is completed, then Even when the tape is stopped in VTR operation, the measurement results are retained in the information processing section (15). Therefore, after the above measurement, the remaining amount can be displayed even if the tape is stopped.

On the other hand, even if a tape cassette is installed and a VTR operation is executed in which the tape is still running, if the execution time is not long enough for the rotation period of both reels to complete, the information processing section (15 ) does not yet have remaining amount data to be displayed. In this state, when the remaining capacity display switch (16) is operated (turned on), the information processing section (15) automatically fast forwards (FF) and rewinds
) is sent to the system control unit (19).

First, the information processing section (15) determines that the current VTR operating state is 1.
The system control unit (
Check the information from 19). “Stop” (“5TOP”)
), and if the tape is running, "Calculating, ("C" or "CALC", etc.) will be displayed and normal reel cycle measurement will start. "Stop J ("5TOP")" will be displayed.
), and if the tape is stopped (such as when executing '5TILL'), it is impossible to display the remaining amount, and the display section (1
8) is cleared, but at this time, it is also possible to display the message "1 remaining amount cannot be displayed." When "Stop J ("5TOP") is confirmed, the information processing section (15) displays "Calculating, ("C" or "CALC", etc.) on the display section (18), and the system control section ( A fast forward (FF) operation is requested for the system controller (19), and after the calculation of the remaining amount of tape is completed, a REW) request signal for rewinding is generated from the system control unit (19), so the system controller (19) enters the "stop" mode. In response to the generation of the request signal, the tape position is returned to the state before the above-mentioned automatic fast forward (FF) and rewind (REW). (The above is referred to as automatic FF/REW in the drawings) When the VTR operates against the intention of the information processing section (15) while executing the automatic FF/REW (operation by the user), the automatic FF/REW R
EW will be canceled immediately.

Regarding the automatic discrimination of the tape cassette, after the rotation period of both reels has been measured, if the measurement was performed at a known and constant tape running speed, the information processing unit (15) , receives a signal from the system control unit (19), and automatically determines the type of tape cassette.

Tυ from 2〇. μm R,'=+= + T a”...
・・・・・・・・・・・・・・・■π From the set of 15■, when 2〇 and 2〇 are added to each side, L・μ R, ” + R, ” = −+ 2 r ”・・...
......■π However, μ, −μ, = μ, r, “r,””r.

In addition, from the formula [phase] from 2〇 and It can be seen that it takes a constant value that is unrelated to the ratio of the tape winding amount.

Also, this value naturally takes a different constant value depending on the type of each tape cassette. From this, both reels (9) (
If the tape running speed υ1, which is the rotation period measured in step 10), is known and constant, the type of fully loaded tape cassette can be known by calculating the sum of the squares of the reel periods.

Here, Ichiho 6-c,=υ R(t % + t ,') shown in FIG. 5 showing the flowchart...
.........0, and the parameters (L, μ, r) of various tape cassettes include tolerances, so for example, a T-30 tape cassette has the following values. has a range of (Distribution 4π(Lμ+2πr) in Figure 5)
C@-as> 4 W (Lse# s*+ 27r
r me)≧C1-3゜・・・・・・・・・・・・・・・
・・・・・・・・・・O.

Here Ll. : T-30 tape total length μsa : T3G tape thickness rse : T-30 hub diameter CI-1@, C6-4°: After calculating C1 shown in parameter formula 0 shown in FIG. 5, The installed tape cassette is determined according to the flow shown in .

However, among the values shown in formula O, T-120 and T-160
As shown in FIG. 5, they overlap, and when the CI is within this range, it is determined as T-120/T-160 based on the state of the aforementioned changeover switch (17).

As is clear from the above explanation, by operating the switch for displaying the remaining amount of tape, the first
In other words, after passing through the mode where the tape speed is constant, the accurate remaining amount is displayed in the second display state according to the installed cassette. indicate.

The first display state is the initial state as shown in FIG.
The digits are displayed in minutes, and then, as a second accurate display state, as shown in FIG. 6 (b), after tape discrimination, the hours and minutes are displayed as day: day and day.

Regarding the remaining amount for a tape cassette that is not in the position of the changeover switch (17), the first display state may be a meaningless value, but once the mode of constant tape speed is passed, the second display state may be a meaningless value. The accurate remaining time will be displayed again as a display state.

(G) Effects of the Invention According to the present invention, after a tape cassette is installed in a VTR, FF/RE can be immediately turned on by operating the switch for displaying the remaining amount of tape.
By performing W, it is possible to provisionally display the remaining amount of tape, and furthermore, as long as the tape is not ejected after passing through the constant tape speed mode, the accurate remaining amount of tape can be displayed based on predetermined data.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the remaining tape amount display device of the present invention, Fig. 2 is a plan view of main parts of the tape cassette, Fig. 3 is a flowchart for explaining the operation of the device, and Fig. 4 is a diagram of the device. A flowchart for tape discrimination, FIG. 5 is a parameter distribution diagram for explaining FIG. 4, and FIG. 6 is a state diagram showing the state of the display section of the apparatus. (1)...Tape cassette, (2)...Tape, (
3)... Supply reel shaft, (5)... Take-up reel shaft, (7)... Pinch roller, (8)... Capstan, (9)... Supply reel, (10)... ... Take-up reel, (11) (12) ... Rotating plate, (13)
(14)...Photo sensor, (15)...Information processing unit, (16)...Remaining amount display switch, (17)
... Selector switch, (1B) ... Display section, (19
)...System control unit. Applicant: Sanyo Electric Co., Ltd. (1 other person) Attorney: Takuji Nishino (1 other person) Patent attorney: 13 ilO (b) Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A supply reel and a take-up reel for transporting the tape in the tape cassette after the tape cassette is installed, and first and second rotation detection means respectively coupled to the two reels;
an information processing section connected to the output ends of the first and second rotation detection means, a system control section that performs various mode selection and control, and connected to the information processing section; and a system control section coupled to the system control. and a display section connected to the information processing section and a changeover switch for setting the tape type, and the position of the changeover switch corresponds to the position of the changeover switch by operation of the operation means for displaying the remaining amount. displaying the remaining tape time calculated by the information processing unit on the display unit;
The information processing section determines the type of tape cassette in response to constant speed running of the tape in playback, recording, or special playback mode, and determines the remaining tape time corresponding to the type of tape cassette. A tape remaining amount display device characterized by displaying information on a display section.