JPS62285065A - Direction of rotation detector for reel base of tape recorder - Google Patents

Abstract

PURPOSE:To obtain a detector capable of detecting the direction of rotation of a reel base, by arranging black and white bands made on a rotary disc to provide information varying with the direction of rotation of the reel base. CONSTITUTION:As a rotary disc 1 adapted to rotate in linkage with the rotation of a reel base turns, light emitted from a light emitting element 2 is made to irradiate a black and white pattern formed thereon 1 and light varying in the level with time is incident into a light receiving element 3 as rotation signal according to difference in the reflectance between separate areas of the black and white pattern. Thus, depending on the direction of rotation of the rotary disc 1, an output pulse train as rotation signal differs in the fashion and is supplied to a microcomputer 5 to judge the direction of rotation.

Description

Detailed Description of the Invention 5. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a tape recorder, and in particular, a method for detecting the rotational direction of a reel stand of a tape recorder suitable for detecting the rotational direction of a reel stand. Regarding equipment.

[Conventional technology]

Conventionally, as a device for detecting the rotation of a reel in a tape recorder, as described in Japanese Patent Publication No. 53-5542, an optical The light passed through or reflected by the crest or mirror surface is received as a rotational signal by a photodetector having a light receiving element, and changes in the rotational speed are detected by the pulse output from the photodetector.

In addition, as another device, a rotating disk is provided on a spindle or the like, and a black and white band is formed in the disk in the case of a reflective type, and a slit is formed in the disk in the case of a transmissive type, and while the disk is rotating, the black and white bands are formed on the disk. The rotational state of the reel stand was detected by irradiating light onto the band or slit, generating pulses in the reflected or transmitted light, and counting these pulses as rotation signals.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, since the state of rotation is known only by the interval and number of detection pulses, it is not possible to know the direction of rotation of the reel stand, and it is difficult to detect the occurrence of reverse rotation due to an abnormality in the tape running system. Therefore, there is a problem in that it is not possible to prevent the tape from being rolled up or to detect the occurrence of a rolled up state.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reel stand rotation direction detecting device for a tape recorder or a tape recorder that can detect the rotation direction of a reel stand.

[Means for solving problems]

The above purpose is to provide a rotating disk on the spindle that drives the reel stand, to make the black and white shading bands or slits formed on the skeleton disk have different widths or patterns, and to send pulses with two or more different widths as rotation signals. This is achieved by configuring the system so that the direction of rotation of the reel stand can be determined based on the output order of the pulses and the like.

[Effect]

The black and white shading bands or slit patterns formed on the rotating disk are formed so that they can give different information depending on the rotation direction of the reel stand, so light is irradiated while the rotating disk is rotating, The direction of rotation is detected by the resulting pulse signal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial block diagram showing an embodiment of a reel stand rotation direction detection device for a tape recorder according to the present invention,
1 is a rotating disk, 2 is a light emitting element, 3 is a light receiving element, 4 is a waveform shaping circuit, and 5 is a signal processing device, such as a microcomputer.

In the figure, light emitted from a light emitting element 2 is reflected by a black and white pattern formed on a rotating disk 1 and enters a light receiving element 3. The output of the light-receiving element 5 is pulse-shaped by a waveform shaping circuit 4 and supplied to a microcomputer 5, where the direction of rotation is determined.

FIG. 2 is a plan view showing an example of a black and white pattern formed on a rotating disk, in which a * b + Oe dr e *
f * g th, 1. ... is each area of the pattern, and a, e, i, ... are black areas, for example, the circumferential angle 3ρ
%blfl... is a white area, for example, circumference angle 1"b O*
g e... is a black area, for example, circumference angle 15°, d, h,
. . . is a white area with a circumferential angle of 300, for example.

3. In the figure, light is not reflected in black areas a, o, e, g, i, . . ., but light is reflected in white areas s, d, f, h, .

FIG. 3 is a timing chart of the received light pulse after waveform shaping, in which (a) shows the output turn when the rotating disk rotates clockwise, and (b) shows the output turn when the rotating disk rotates counterclockwise. *Qsd, e, f, g, h, i, . . . are output pulse waveforms corresponding to the regions indicated by the same symbols in FIG. 2; 1. ．． 12 is a pulse period.

In FIG. 1, when the rotating disk 1 that rotates in conjunction with the rotation of the reel stand rotates, the light emitted from the light emitting element 2 is irradiated onto the black and white pattern formed on the rotating disk 1. Light having different levels over time enters the light receiving element 3 as a rotation signal depending on the difference in reflectance of each region.

The output of the light receiving element 3 is converted into an electrical signal corresponding to the incident light by the resistor R, and is applied to the waveform shaping circuit 4.

Figure 3 shows the pulse waveform after shaping corresponding to each area of the black and white pattern shown in Figure 2, where the input level is high (hereinafter referred to as H level) in the white area and 4+, and low in the black area. (hereinafter referred to as L level).

First, when the rotating disk 1 is rotating clockwise (a) in FIG. 2, the output pulse train from the waveform shaping circuit 4 is the fifth pulse train.
The pattern is as shown in Figure (a).

When the rotating disk 1 is rotating counterclockwise (b) in FIG. 2, the output pulse train from the waveform shaping circuit 4 has a pattern as shown in FIG. 5, 6).

In this way, the output pulse train, which is a rotation signal, has different patterns depending on the rotation direction of the rotating disk. The direction of rotation of the rotating disk 1 can be detected based on the difference in pattern between the two.

Various methods can be considered as this detection method, examples of which will be explained below.

In the timing chart of FIG. 3, the same level period (H level in the figure) of the output pulse of the waveform shaping circuit 4 at a given time is tl, and the next period of the opposite level (L level in the figure) is t2. do.

Then, as shown in Table 1 below, when the output pulse level changes from H to L when the rotating disk rotates clockwise, t = t2. If it changes to L-+H, 1. +1
There is a relationship of 2. When rotating counterclockwise, K H-+ L K changes in the opposite direction to the above: j, 4t2. L-
+) 1 if it changes to l. The relationship is +12.

FIG. 4 of Table 1 is a flowchart illustrating the operation of the microcomputer 5 for determining the rotation direction from the relationship between the period t corresponding to the level change and the period t2. Measure the period of a continuous period t1 @ t2 from an arbitrary time of the pulse train from , memorize the input level at t1, and input t when it is H level, clockwise if -t2 holds, Not established (1
，? In the case of 12), it is determined that the rotating disk 1 is rotating counterclockwise.

When period t is at L level, it is determined that the rotating disk 1 is rotating counterclockwise if I/ct, = t2 holds, and clockwise if it does not hold (t,,Xt,2). do.

The flowchart of FIG. 4 showing the operation of the microcomputer 5 for making the above judgment will be briefly explained.

First, when the judgment cycle starts, the first edge of the input pulse from the waveform shaping circuit is detected. Once the edge is detected, a measurement is made for a period of time, t. The detection of the next edge of the pulse ends the measurement of period t, and the period t
Start measurement 2.

When the edge of the pulse is detected again, the measurement for period t2 ends.

Next, determine the level of the pulse in period t, and if it is at the ■ level, determine whether period t and period t2 are equal or not, and if appropriate, determine clockwise rotation. .

Further, when the level of the pulse in the period t is L level, it is determined whether the period t and the period t2 are equal or not, and if they are equal, it is determined that the rotation is in the counterclockwise direction φ 7 ·. When it is determined that the period t and the period t2 are not equal, it is determined that the pulse level of the period t is H level and L level, respectively, to rotate counterclockwise and clockwise. .

In the above embodiment, the rotation signal, that is, the pulse extraction means formed on the rotating disk is a black and white shading pattern.
As described above, a similar effect can be obtained by configuring a pattern of slits with different widths so that light from the light emitting element passes through the core slit of the rotating disk and reaches the light receiving element. Note that the pulse extraction means is not limited to the above-mentioned one, and may of course be of any type as long as it outputs different pulse patterns depending on the direction of rotation of the rotating disk.

〔Effect of the invention〕

As explained above, according to the present invention, a rotating disk is provided on the spindle that drives the reel stand, and information that can determine the rotational direction, such as black and white shading patterns and slits, is formed on this rotating disk. The conventional device, which is capable of detecting the direction of rotation of the table, is equipped with an optical rotation detection device, and is controlled by a microcomputer, uses a pulse generation pattern formed on a rotating disk and software. There is also an advantage that the rotation direction can be easily detected by only changing the above, and it is possible to eliminate the drawbacks of the above-mentioned prior art and provide a tape recorder reel stand rotation direction detection device with excellent functions.

[Brief explanation of drawings]

FIG. 1 is a partial block diagram showing an embodiment of a reel stand rotation direction detection device for a tape recorder according to the present invention, and FIG. 2 is a plan view showing an example of a black and white pattern formed on a rotating disk.
FIG. 3 is a timing chart of the received light pulse after waveform shaping, and FIG. 4 is a flowchart illustrating the operation of the microcomputer for determining the rotation direction. DESCRIPTION OF SYMBOLS 1... Rotating disk, 2... Light emitting element, 3... Light receiving element, 4... Waveform shaping circuit, 5... Microcomputer.

Claims (1)

[Claims] 1. A rotating disk that rotates in conjunction with the rotation of the reel stand, a rotation signal generating means formed on the rotating disk, a light emitting element that irradiates light to the rotation signal generating means, and light from the light emitting element. and a light receiving means for receiving light through the rotation signal generation means, the rotation signal generation means is configured to give different information depending on the rotation direction of the rotating disk. 1. A reel stand rotational direction detection device for a tape recorder, characterized in that the reel stand rotational direction detection device is configured to detect the rotational direction of the reel stand.