JPH11109515A - Braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a stable braking force with a simple and compact constitution, by applying the braking force to the rotation of a rotating part by a magnetic field generating means respectively provided at the rotating part and a fixed part. SOLUTION: A brake part 90 has a fixed side cylinder part fixed onto a fixed shaft 55 and a rotating side cylinder part fixed on a sprocket 60. As for the fixed side cylinder, a 1st cylindrical magnetic cylinder having plural magnetic poles is fixed on the outer peripheral surface of a cylinder 93 inserted through the shaft 55. As for the rotating side cylinder part, a 2nd cylindrical magnetic cylinder having plural magnetic poles is rotatably attached on the outer peripheral side surface of the 1st magnetic cylinder by holding a gap (g) in between. Furthermore, an almost cylindrical resin case is fixed to cover over the 2nd magnetic cylinder. By rotating the rotating side cylinder part in a state where the fixed side cylinder part is fixed, the braking force to prevent the rotation of the rotating side cylinder part by the magnetic poles is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order.

BACKGROUND OF THE INVENTION Prior Art (FIGS. 16 to 18) Problems to be Solved by the Invention Means for Solving the Problems Embodiments of the Invention (FIGS. 1 to 5) Effects of the Invention

[0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device, and is suitably applied to, for example, a braking device for applying a predetermined tension to a movie film running in a projection device.

[0004]

2. Description of the Related Art Conventionally, as a projector used in a movie theater, there is a projector which uses a movie film in which an image and a sound are recorded on the same film and reproduces the image and the sound corresponding to the image at the same time. That is, FIG.
As shown in FIG. 6, this movie film 1 is formed by sequentially recording each frame image 4 obtained by frame-taking a series of moving images in the longitudinal direction, and each frame image 4 is formed along both side edges of the movie film 1. The holes 2 for film feeding (hereinafter referred to as perforations) 2 are sequentially formed so as to sandwich the film.

The movie film 1 can run in the longitudinal direction by engaging the perforation 2 with a sprocket for feeding the film and rotating the sprocket.

Here, the movie film 1 has an analog audio track 5 between each frame image 4 and one of the perforation rows 3A. The analog audio track 5 optically records an amplitude-modulated analog audio signal, and the analog audio signal is optically read by an analog audio reproducing unit provided in the projector.

The movie film 1 has digital audio tracks 6A and 6B in addition to the analog audio track 5. The digital audio tracks 6A and 6B are formed outside the perforation rows 3A and 3B, respectively, along both side edges of the movie film 1, and the digital audio tracks 6A and 6B contain digital audio information, respectively. 17, a binary pattern of black (the part where the film is exposed) and white (the part where the film is not exposed) as shown in FIG. 17 are sequentially recorded in the scanning direction a substantially perpendicular to the running direction of the movie film 1. Have been. Each digital audio track 6A and 6
In B, four channels of digital audio information are recorded in units of predetermined data blocks.

[0008] As shown in FIG. 18, the projection apparatus 10 winds the movie film 1 wound on a supply reel 11 on a take-up reel 14 via a digital audio reproduction unit 12 and a projector 13. ing. In this case, the running of the movie film 1 is controlled at a predetermined speed in response to a sprocket for feeding the film (not shown) provided in the projector 13 being rotated by a predetermined motor.

The digital audio reproducing unit 12 receives the movie film 1 supplied from the supply reel 11 to the sprocket 18 via guide rollers 15, 16 and 17 in order, and furthermore, the optical reading unit via the tension roller 19. After winding about 180 ° around 25 flywheels 20,
It is again received by the sprocket 18 via the tension roller 21.

The tension rollers 19 and 21 are biased toward each other by a predetermined spring, so that the movie film 1 fed from the sprocket 18 to the flywheel 20 has the sprocket 18 and the flywheel 20 attached thereto. A predetermined tension is applied between them by a tension roller 19 and a flywheel 20
A predetermined tension is applied between the flywheel 20 and the sprocket 18 by the tension roller 21 to the movie film 1 sent to the sprocket 18. Accordingly, the movie film 1 wound around the flywheel 20 surely runs in close contact with the flywheel 20 while receiving a predetermined tension.

Here, the movie film 1 sent from the sprocket 18 to the flywheel 20 and the movie film 1 sent from the flywheel 20 to the sprocket 18 are meshed with the same sprocket 18, respectively. Flywheel 20
After being wound into the flywheel 20 and wound around the flywheel 20, the movie film 1 is meshed with the sprocket 18 again, and the disturbance such as the fluctuation of the tension generated in the movie film 1 outside the digital sound reproducing unit 12 is generated. It forms a closed loop that does not add. Accordingly, only the tension rollers 19 and 21 determine the tension of the movie film 1 wound around the flywheel 20 (that is, the adhesion of the movie film 1 to the flywheel 20).

Further, a base plate 27A is fixed to the front side of the cabinet 27 constituting the housing of the digital audio reproducing unit 12, and the back side of the base plate 27A (that is, the inside of the cabinet 27). Is mounted with a braking motor (not shown) for applying a predetermined tension to the movie film 1. The output rotation shaft of this motor is fixed to the rotation shaft 18A of the sprocket 18 which rotates integrally with the sprocket 18. By applying a drive voltage to the braking motor, the rotation of the sprocket 18 is performed in accordance with the running of the movie film 1. A rotating force in a direction opposite to the rotating direction is applied to the sprocket 18 rotating in a predetermined direction. As a result, a braking force is applied to the movie film 1 in a direction opposite to the running direction, and from the sprocket 18 via the guide rollers 22, 23 and 24, the projector 13 is moved.
Is applied to the movie film 1 to the extent that the running thereof can be stabilized.

The height of the movie film 1 fed to the flywheel 20 from the base plate 27A is regulated by the guide roller 17 and the tension roller 19. In this case, the guide roller 17 regulates the movie film 1 in a direction away from the base plate 27A,
The tension roller 19 regulates the movie film 1 in a direction approaching the base plate 27A.

Here, the flywheel 20 is rotatably supported on the base plate 27A of the digital audio reproducing unit 12, and rotates as the movie film 1 runs while winding the movie film 1. In the vicinity of the flywheel 20, a light emitting unit 26A and a light receiving unit 26B are provided so as to hold the movie film 1 therebetween and maintain a predetermined positional relationship.

In the optical reading section 25, a light emitting section 26A
Has a pair of light emitting diodes (LEDs), and each LE
D is a digital audio track 6A recorded along both side edges of the movie film 1, respectively.
And 6B (FIG. 16).

The digital pattern images of the digital audio tracks 6A and 6B obtained by transmitting the irradiation light through the movie film 1 are formed on the sensor of the light receiving section 26B. The sensor scans the sequentially irradiated digital pattern images line by line in the width direction of the movie film 1 and decodes the signals obtained based on the digital pattern images for each line as detection signals (see FIG. 1). (Not shown).

The decoder sequentially reproduces the digital audio information recorded in each of the digital audio tracks 6A and 6B of the movie film 1 based on the supplied detection signal, and reproduces the digital audio information in a digital audio reproduction signal S2 (FIG. 1).
8) to supply the corresponding speaker 29 via the amplifier 28. Thus, the speaker 29 can transmit a sound based on the digital sound reproduction signal S2.

The projector 13 draws the movie film 1 from the digital sound reproducing unit 12 at a substantially constant speed by a film feeding sprocket (not shown) provided therein, and is further provided inside the projector 13. While the movie film 1 is intermittently fed at a predetermined timing by the intermittent feed section (not shown), the movie film 1 is intermittently fed.
The projection light is transmitted through each frame image 4 (FIG. 16), and the transmitted light is radiated to the screen 31 via the projection lens unit 30. Thus, the projector 13 can reproduce a series of moving images by sequentially projecting the images recorded in each frame image 4 of the movie film 1 on the screen 31.

[0019]

In the projection device 10, the sprocket 18 in the digital sound reproducing unit 12 and a motor (not shown) as its braking means are connected to one side via a base plate 27A. The output shaft of the motor is provided on the other surface,
Is fitted and fixed to the rotating shaft 18A of the sprocket 18.

When the movie film 1 is running, a pressing force is applied in a direction substantially perpendicular to the rotating shaft 18A of the sprocket 18 in accordance with the tension of the movie film 1, so that the rotating shaft 18A of the sprocket 18 and / or the output shaft of the motor. If the strength is low, they may bend and cause shaft runout.

As a result, even though a predetermined electromotive force is applied to the motor so that a constant torque is always applied in the direction opposite to the rotation direction during film running, the output shaft of the motor fluctuates during rotation. As a result, there is a problem that a torque change occurs on the output shaft.

In order to solve this problem, a method of increasing the strength by enlarging the diameter of the rotation shaft 18A of the sprocket 18 and the output shaft of the motor may be considered. However, in general, the motor body tends to increase in size and weight in proportion to the diameter of the output shaft. For this reason, there has been a problem that the digital audio reproducing device section 12 becomes large as a whole.

At the time of manufacture and maintenance of the digital audio reproducing unit 12, the sprocket 18 and the motor must be attached or detached from both sides of the base plate 27A, and these must be attached or detached from only one side of the base plate 27A. There is a problem that the working efficiency is remarkably reduced as compared with the case of performing.

By the way, the digital audio reproducing unit 12
As a braking means for the sprocket 18 inside, a brake disk (not shown) whose center is fitted and fixed to the rotation shaft 18A of the sprocket 18 via a base plate 27A instead of the above-described method using a motor, Base plate 27A
A method of braking the brake disk by sandwiching it from both sides with a pair of brake pads fixed to the brake disk is considered.

In the braking method using the brake disk, the rotational speed of the brake disk is reduced by the frictional force generated on the contact surface between the brake disk and each brake pad. In order to always apply a constant torque in the reverse direction, it is necessary to finely adjust the pressing force of each brake pad against the brake disk.

However, since the coefficient of friction of the brake pad against the brake disk changes according to changes in temperature and humidity, it is very difficult to finely adjust the pressing force of each brake pad against the brake disk.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a braking device which has a simple configuration and can be reduced in size.

[0028]

In order to solve the above-mentioned problems, according to the present invention, a rotating portion of a braking device is engaged with roller means rotating as the belt travels, and the rotating portion and the fixed portion are respectively engaged with the rotating portion and the fixed portion. By applying a braking force to the rotation of the rotating unit by the provided magnetic field generating means, a stable braking force can be applied with a simple and small configuration.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, in which parts corresponding to those in FIG. 18 are assigned the same reference numerals, a projection apparatus 50 transfers a movie film 1 wound on a supply reel 11 via a digital audio reproduction unit 51 and a projector 13. The take-up reel 14 takes up the work. In this case, movie film 1
Is controlled at a predetermined speed in response to the rotation of a sprocket 13A for film feeding provided in the projector 13 by a predetermined motor.

As shown in FIG. 2, the digital sound reproducing device 51 receives the movie film 1 by a stabilizer (guide roller) 82 via a guide roller 81. The guide roller 81 is provided on a front surface of a base cabinet 150 (hereinafter, referred to as a base surface portion) constituting a main body of the digital audio reproducing device 51 so that a winding angle of the movie film 1 around the stabilizer 82 falls within a predetermined range. ) 1
It is arranged at a predetermined position of 50A.

The stabilizer 82 has a pivot shaft 82C with respect to the base surface 150A of the base cabinet 150.
The roller 82A is pivotally supported at the tip of a rotating arm 82B rotatably supported, and the rotating arm 82B has a biasing force at a predetermined rotating position by a spring (not shown). By applying a predetermined tension to the movie film 1, the running of the movie film 1 can be stabilized.

The movie film 1 supplied via the stabilizer 82 is engaged with the sprocket 60. The sprocket 60 is rotatably supported on a fixed shaft 55 fixed to the base surface portion 150A so as to be rotatable about a center of rotation. A frequency generating cylinder 75A that is a part of the device unit 75 is provided,
It rotates integrally with the sprocket 60 about the fixed shaft 55 as the center of rotation.

At a predetermined position of the base surface portion 150A,
As shown in FIG. 3, a rotation arm 85 is pivotally supported about a rotation center shaft 85A as a rotation center. Two rollers 83 and 84 are pivotally supported by the rotating arm 85, and rotate integrally with the rotating arm 85. The rotating arm 85 is urged to rotate in a direction approaching the sprocket 60 by a predetermined urging means.
And 84 are positioned close to the sprocket 60 so that the film 1 can be securely engaged with the sprocket 60.

A brake device is built in the sprocket 60, and a predetermined tension is applied to the moving movie film 1 by the sprocket 13A (FIG. 1) for feeding the film of the projector 13. That is, as shown in FIG. 4, the fixed shaft 55 of the sprocket 60 is
By fixing one end 55A to the base surface 150A of the base cabinet 150, the entire end is fixed to the base surface 150A. Incidentally, the decorative plate 54 is fixed on the base surface 150A with a predetermined gap from the base surface 150A, and the fixed shaft 55 is fixed via the opening 54A of the decorative plate 54.

Sprocket 60 and frequency generating cylinder 7
5A is integrated by a fastening screw (not shown),
It is rotatably supported on the fixed shaft 55 via bearings 100 and 101. As shown in FIG. 5, the integrated sprocket 60 and the frequency generating cylinder 75A have storage holes 60H and 75H in their respective interiors, and have a substantially cylindrical outer shape in the storage holes 60H and 75H. The brake unit 90 is housed as brake means for applying a braking force to the rotation of the sprocket 60.

As shown in FIG. 6, the brake portion 90 is fixed to the cylinder portion 91 (hereinafter, referred to as a fixed-side cylinder portion) fixed to the fixed shaft 55 (FIG. 4) and to the sprocket 60. (Hereinafter, referred to as a rotation side cylinder portion) 92, and the rotation side cylinder portion 92 is fixed to the fixed shaft 55 with a gap g from the outer peripheral surface of the fixed side cylinder portion 91. Is freely fitted in the sprocket 60 (FIG. 4) so as to be rotatable in the rotation direction (the direction of the arrow r).

The fixed-side cylinder portion 91 has a cylindrical first magnetic cylinder 94 having a plurality of magnetic poles (S-pole and N-pole) fixed to the outer peripheral surface of a cylinder 93 through which the fixed shaft 55 is inserted. ing. In the rotation-side cylinder portion 92, a cylindrical second magnetic cylinder 9 having a plurality of magnetic poles (S-pole and N-pole) is provided.
5 is rotatably attached to the outer peripheral side surface of the first magnetic cylinder 94 with a gap g interposed therebetween, and a substantially cylindrical resin case 96 is fixed so as to cover the second magnetic cylinder 95. I have.

When the rotating cylinder 92 is rotated in the direction indicated by the arrow r in the state where the fixed cylinder 91 is fixed, the magnetic poles prevent the rotation of the rotating cylinder 92 from being stopped. Power is generated.

Here, the fixed-side tubular portion 91 is engaged with the fixed shaft 55 (FIG. 4) supporting the sprocket 60, and the rotating-side tubular portion 92 is engaged with the sprocket 60 to be integrally formed with the sprocket 60. It is attached to rotate. That is, as shown in FIG. 7, engaging protrusions 96A and 96B integrally formed with the resin case 96 are provided at one end of the rotation-side cylindrical body 92 of the brake unit 90 at an angular interval of about 180 °. Each of the sprockets 60 is formed so as to protrude in a direction parallel to the central axis of the cylindrical body, and is fitted into fitting grooves 60G and 60H formed at the bottom of the fitting hole 60H of the sprocket 60. As a result, the rotation-side cylindrical portion 92 of the brake portion 90 rotates integrally with the sprocket 60 in accordance with the rotation of the sprocket 60.

A pin hole 55X is formed at a predetermined position of the fixed shaft 55 in a radial direction of the fixed shaft 55, and a pin 56 is fitted into the pin hole 55X so that both ends thereof are slightly projected. I have. On the other hand, the brake unit 90
At the end of the cylindrical body 93 of the fixed-side cylindrical body part 91,
Notches 93GA and 93GB are formed at intervals of 80 ° so that the pins 56 can be inserted therein.

When the brake portion 90 is mounted on the fixed shaft 55, the fixed shaft 55 is inserted into the fixed side cylindrical portion 91 of the brake portion 90, so that the pin 56 mounted on the fixed shaft 55 is fixed. It is inserted into the notches 93GA and 93GB formed in the cylindrical body 93 of the cylindrical body part 91, whereby the fixed side cylindrical body part 91 of the brake part 90 is fixed to the fixed shaft 5
5 can be fixed.

Incidentally, the brake unit 90 and the sprocket 6
As a method for attaching the zero and frequency generating cylinder 75A to the fixed shaft 55 on the base surface part 150A, the sprocket 60 and the frequency generating cylinder 75A are integrated with the brake part 90 housed inside them, and the brake part is integrated. 90
After the fixed shaft 55 is inserted into the cylindrical body 93 and the whole is supported by the bearings 101 and 100, the distal end of the fixed shaft 55 is screwed with the mounting screw 102, or the frequency generating cylindrical body 75A. Is mounted on the fixed shaft 55 via the bearing 101, and then the brake unit 90 and the sprocket 60 are mounted and screwed with the mounting screw 102. In any case, the base surface of the base cabinet 150 is provided. The sprocket 60, the frequency generating cylinder 75A, and the brake unit 90 can be attached from the outside of the 150A (that is, from the side where the user handles the digital sound reproducing unit 51).

When the sprocket 60 rotates as the movie film 1 runs, the rotation-side cylinder 92 rotates with respect to the fixed-side cylinder 91 in the brake unit 90, thereby rotating the sprocket 60 with respect to the sprocket 60. A braking force to be braked is applied, and the movie film running between the film feeding sprocket 13A (FIG. 1) on the projector 13 side and the sprocket 60 on the digital sound reproducing device section 51 side, which is the driving source of the movie film 1. 1
, A predetermined tension is applied.

The movie film 1 supplied through the sprocket 60 in this manner has a height from the base surface 150A by the position regulating guide 200 (FIG. 2) provided following the sprocket 60. Adjusted.

That is, as shown in FIG. 8, the position regulating guide portion 200 has one end 201A on the base surface portion 150A.
The two guide rollers 20 are fixed to a fixed shaft 201 by fixing
2 and 203 are bearings 205L, 205H and 20
It is rotatably supported via 6L and 206H.

The guide roller 202 receives an urging force in a direction away from the base surface portion 150A by a coil spring 208 inserted between the large diameter portion 207 of the fixed shaft 201 and the bearing 205L. It is positioned at a position where it comes into contact with the E-ring 204 fixed partially.

The guide roller 203 has a fixed shaft 201.
The base surface portion 15 is formed by the coil spring 209 inserted between the E-ring 204 fixed to the head and the bearing 206L.
0A and receives a biasing force in a direction away from the fixed shaft 2.
It is positioned at a position where it comes into contact with the adjusting screw 210 screwed to the distal end of the “01”. This position is adjusted by adjusting the screwing amount of the adjusting screw 210 into the fixed shaft 201.

Thus, the guide roller 203 whose distance from the base surface portion 150A has been adjusted by the adjusting screw 210.
Is one side edge 1H of the movie film 1 (the base surface 1
Base surface 150 at a side edge farther from 50A)
The guide roller 202, which regulates the distance from the base film 150 A by the E-ring 204 and sets the distance from the base surface 150 A by the E-ring 204, is the other side edge 1 of the movie film 1.
The distance L from the base surface portion 150A is restricted from L (side edge portion closer to the base surface portion 150A).

In this case, the guide roller 202 is constantly urged by the coil spring 208 in the direction in which it comes into contact with the E-ring 204, so that the guide rollers 202 and 203
The movie film 1 running while being engaged with the
Even if an attempt is made to displace in the direction approaching 0A, the running position is always regulated by the urging force of the coil spring 208. Further, since the guide roller 203 is adjusted in the distance from the base surface 150A by the adjusting screw 210, even if the movie film 1 is displaced in the direction away from the base surface 150A, the guide roller 20 is displaced.
3, the travel position is always regulated.

In this manner, the position regulating guide portion 200
The film film 1 whose distance from the base surface portion 150A is regulated by this is wound around the flywheel 65 of the optical reading section 70 at a predetermined winding angle in FIGS. This winding angle is determined by the position regulating guide 20.
0 and the arrangement position of the guide roller 86.

The flywheel 65 includes a base surface 150
A is rotatably supported by a predetermined rotation shaft (not shown) on A, and rotates with the running of the movie film 1 wound around the flywheel 65. In the vicinity of the flywheel 65, a light emitting section 71 and a light receiving section 72 constituting the optical reading section 70 are provided so as to maintain a predetermined positional relationship sandwiching the movie film 1.

In the optical reading section 70, a frequency generating cylinder 75A integrated with the sprocket 60 (FIG.
When a frequency signal is output from the frequency generating device unit 75 including the frequency generating cylinder 75A with the rotation of FIG. 5), the light emitting unit 71 emits light at a timing based on the frequency signal. I have.

That is, as shown in FIG. 9, the frequency generator 75 is provided as a rotation detecting device for the sprocket 60, and the frequency generating cylinder 75A as a reflection member fastened to the sprocket 60 and the base surface 150A.
This is constituted by a photo sensor 180 fixed to the camera. The frequency generating cylinder 75A is set to have a length that fits in the gap between the sprocket 60 and the base surface 150A, and is inserted into the gap through an opening 54A formed in the decorative plate 54. The sprocket 60 and the frequency generating cylinder 75A integrally fastened together have a bearing 100.
And 101 are rotatably supported on the fixed shaft 55 via the shaft 101.

In the photo sensor 180, approximately L
A mounting plate 183 is fixed at one end 183A to a predetermined position on the base surface 150A by screws 184, and a fixing substrate 185 and a light emitting / receiving cell 187 are mounted on the other end 183B of the mounting plate 183. It is fixed by screws 186.

The light emitting / receiving cell 187 has an LED (Light Em
A light emitting element 180A made of an itting diode and a light receiving element 180B made of a photodiode are provided in parallel with the axial direction of the fixed shaft 55 so as to face the peripheral side surface of the frequency generating cylinder 75A. Have been.
The light emitting element 180A emits far infrared rays to the peripheral side surface of the frequency generating cylinder 75A by a control circuit provided on the fixed substrate 185.

As shown in FIG. 10, the frequency generating cylinder 7
5A has a flange portion 75B having a plurality of screw holes 75BH formed at one end thereof, and the flange portion 75B is screwed to the sprocket 60 to thereby form a sprocket 6A.
It is designed to be able to rotate integrally with the zero. The frequency generating cylinder 75A has the same number of notches 7 as the engagement projections 60A of the sprocket 60 at a predetermined angular interval on the peripheral side surface.
When the 5G is formed and rotated with the sprocket 60, the rotation of the sprocket 60 is detected by sequentially detecting the notches 75G and the protrusions 75T between the notches 75G by the photo sensor 180. be able to.

As shown in FIG. 11, the frequency generating cylinder 7
Notch 75G formed in 5A and photo sensor 180
The distance D2 between the light receiving element 1 and the light (far infrared ray) emitted from the light emitting element 180A passes through the notch 75G.
The distance is set to such an extent that light cannot be received at 80B, and the projections 7 formed on the frequency generation cylinder 75A
The distance D1 between 5T and the photo sensor 180 is
5T is a photo sensor 1 according to the rotation of the sprocket 60.
After the light emitted from the light emitting element 180A is reflected by the convex portion 75T in a state facing the light receiving element 80, the light receiving element 18
The distance is set to 0B so that the light can be reliably received.
These distances D1 and D2 are determined by the intensity of light emitted from the light emitting element 180A and the light receiving sensitivity of the light receiving element 180B.

Thus, in the frequency generation device 75, when the frequency generating cylinder 75A rotates with the rotation of the sprocket 60, the position facing the photo sensor 180 is only moved while the convex portion 75T of the frequency generating cylinder 75A crosses. By receiving the reflected light from the convex portion 75T at the light receiving element 180B, a rotation detection signal (SFG) having a frequency corresponding to the rotation speed of the frequency generating cylinder 75A (that is, the sprocket 60) is obtained.

As shown in FIG. 12, the frequency generator 7
5 is a rotation detection signal S output from the photo sensor 180 of FIG.
The FG is supplied to the timing generator 90 in the light emitting section 71 of the optical reading section 70.

The timing generator 90 binarizes the supplied rotation detection signal SFG into a logic “H” level and a logic “L” level with a predetermined threshold as a reference. In this way, the pulse signal SPL in which the logic “H” level and the logic “L” level alternately appear in accordance with the frequency of the rotation detection signal SFG is supplied from the timing generator 90 to the light emission control unit 91.

The light emission control section 91 controls the lighting of the LEDs 35A and 35B based on the supplied pulse signal SPL, thereby controlling the timing at which the LEDs 35A and 35B are turned on by rotating the frequency generating cylinder 75A (that is, the sprocket 60). Rotation).

As a result, light LA and LB composed of far infrared rays are emitted from the LEDs 35A and 35B in synchronism with the running speed of the movie film 1, respectively, and both sides of the movie film 1 are passed through the corresponding optical fibers 36A and 36B. Digital audio track 6 recorded along the edge
A and 6B are irradiated.

The transmitted light LA transmitted through the movie film 1
1 and LB1 are digital audio tracks 6A and 6B
Of the light receiving unit 72
7A and 37B, and the corresponding CCD (Char
The image is formed on the sensors 38A and 38B having a “ge Coupled Device” configuration.

The sensors 38A and 38B scan the digital pattern images (LA1 and LB1) sequentially irradiated line by line in the width direction of the movie film 1 and obtain the digital pattern images on a line-by-line basis. The supplied signal voltages are supplied to the subsequent decoder 39 as detection signals S1A and S1B, respectively.

At this time, since the digital pattern images are sequentially incident on the sensors 38A and 38B in synchronization with the running speed of the movie film 1, the sensors 38A and 38B
Can accurately scan a digital pattern image one line at a time in synchronization with the running speed of the movie film 1. Thus, for example, even when the running speed of the movie film 1 is reduced, the operation of scanning the once-scanned line repeatedly can be avoided.

The decoder 39 supplies the supplied detection signal S1
The digital audio information recorded on each of the digital audio tracks 6A and 6B of the movie film 1 is sequentially reproduced based on A and S1B, respectively, and the digital audio information is corresponded via the amplifier 28 as a digital audio reproduction signal S2 for a plurality of channels. To a plurality of speakers 29 to be used. Thus, the plurality of loudspeakers 29 can each transmit sound based on the digital reproduction signal S2 corresponding to each channel.

As described above, the projection apparatus 50 reproduces the audio information of the digital audio tracks 6A and 6B of the movie film 1 in the digital audio reproduction unit 51 and the movie film 1 in the projector 13 (FIG. 1).
Are successively projected onto the screen 31 via the projection lens 30 to reproduce a series of moving images composed of the frame images 4 as the movie film 1 travels.

FIG. 13 shows a base cabinet 150 which is a housing device of the digital sound reproducing device 51 as a whole, and the guide rollers 8 described with reference to FIG.
1, 82, 83, 84, 86, the sprockets 60, the position regulating guide 200, and the base surface portion 150A provided with the optical reading portion 70 are front faces. It has a shape.
The base cabinet 150 is formed by extruding aluminum.

In the extrusion method, a product having a desired cross-sectional shape is obtained by extruding a metal material such as aluminum from a die called a die. The product formed by the extrusion method has a continuous and constant cross section, and is cut into a predetermined length according to the purpose of use. The extrusion method is
Products having a constant cross section can be easily manufactured, and products having various shapes such as a solid rod-shaped product, a hollow pipe-shaped product, and a plate-shaped product can be formed depending on the shape of the die.

The base surface 150A formed on the front side of the base cabinet 150 is provided with a plurality of screw holes 146 for mounting components. The components constituting the guide rollers 81, 82, 83, 84, 86, the sprockets 60, the position regulating guide portion 200, and the optical reading portion 70 described above with reference to FIG. 2 are screwed into these screw holes 146. .

These components are connected to the base cabinet 150.
In the case where the base cabinet 150 is mounted, all the mounting operations can be performed from outside the base surface portion 150A of the base cabinet 150. That is, as shown in FIG. 14, for example, the guide roller 86 is connected to the base cabinet 15.
0, the fixed shaft 86B is first screwed into the corresponding mounting screw hole 146, then the roller spring 86C is inserted into the fixed shaft 86B, and then the guide roller 86 is inserted via a bearing. By screwing the roller screw 86A to the tip of the fixed shaft 86B, the guide roller 86 is rotatably supported by the fixed shaft 86B.

Similarly, when attaching the sprocket 60 to the base cabinet 150, the fixed shaft 55 is first screwed into the corresponding mounting screw 146, then the sprocket 60 is inserted into the fixed shaft 55, and finally the fixed shaft 55 is inserted. The screw 102 is screwed to the tip of the screw 55. Incidentally, in FIG. 14, FIG.
Although the brake unit 90 and the frequency generating cylinder 75A described above are omitted, they can also be attached by inserting them into the fixed shaft 55 together with the sprocket 60 in the same manner. Thus, the base surface 150A
All parts to be mounted on the base cabinet 1
Attached from outside of 50.

Base surface 1 of base cabinet 150
At the top and bottom of 50A, base surface side plate 1
42 are provided. This base surface portion side plate 142
The top and bottom plates of the base cabinet 150 are provided extending from the base surface 150A. Further, a decorative plate 54 formed by processing a metal plate into a U-shape is attached to the base surface 150A.

Here, as shown in FIG. 15, a plurality of circuit boards 34 are housed inside the base cabinet 150. In this case, the inner surface of the base cabinet 150 includes
A plurality of concave substrate guides 144 are simultaneously formed in the extrusion direction when the base cabinet 150 is formed in the extrusion step, and the substrate guides 144 are formed.
The circuit board 34 can be easily housed in the base cabinet 150 by inserting the circuit board 34 along the line.

The circuit board 34 is mounted on the base cabinet 150.
After being inserted into the storage section cover 148 using the cover screw 149.
Is screwed to the end face of the base cabinet 150, whereby the inside of the base cabinet 150 is closed to the outside, so that dust and the like can be prevented from entering the inside of the base cabinet 150.

In FIG. 13, a heat sink 145 is formed on the rear surface of the base cabinet 150 opposite to the base surface 150A. Heat sink 145
Are formed at the same time when the base cabinet 150 is formed by the extrusion method, and are a plurality of pleated portions extending in the left-right direction of the base cabinet 150. When the surface area of the base cabinet 150 is increased by the heat sink 145, the heat generated by the circuit board 34 housed in the base cabinet 150 is released to the outside via the heat sink 145.

In the above configuration, the digital sound reproducing device 51 has a brake unit 90 for generating a braking force by a magnetic force in the sprocket 60 as a braking device for applying a predetermined tension to the movie film 1. 60
When the wheel rotates, the braking portion 90 generates a braking force acting as a load on the rotation of the sprocket 60.

Since the brake unit 90 performs the braking by the magnetic force, the braking force does not change due to the fluctuation of the rotation of the sprocket 60. Therefore, even if the running speed of the movie film 1 fluctuates, a constant tension is always applied to the movie film 1.

The brake section 90 is provided on the base surface section 150A.
The front side of the base cabinet 150 (ie, the outside of the base cabinet 150) can be housed inside the sprocket 60, and maintenance such as mounting and dismounting of the brake unit 90 can be performed only from the outside of the base cabinet 150. It can be carried out. And since the brake part 90 is provided outside the base surface part 150A,
There is no need to provide a large brake motor as in the prior art inside the base cabinet 150, so that the inside of the base cabinet 150 can be effectively used.

Thus, according to the above configuration, the brake unit 90 for applying a braking force to the rotation of the sprocket 60 by the magnetic force is provided inside the sprocket 60, so that a more stable control can be achieved with a simple and compact configuration. Power can be added.

In the above embodiment, the case where the brake unit 90 is provided inside the sprocket 60 has been described. However, the present invention is not limited to this, and the sprocket 60 is not limited to this.
May be provided between the sprocket 60 as a rotating body and the fixed shaft 55 on the fixed side.

In the above-described embodiment, a case has been described in which the present invention is applied to the braking device for applying tension to the movie film 1 of the digital sound reproducing device section 51.
The present invention is not limited to this, and can be widely applied to braking devices of various other devices, such as a braking device that applies a predetermined tension to a tape of a tape recorder.

[0084]

As described above, according to the present invention, the rotating portion of the braking device is engaged with the roller means which rotates as the belt moves, and the magnetic field generation provided on the rotating portion and the fixed portion, respectively. By applying a braking force to the rotation of the rotating unit by the means, a braking device capable of applying a stable braking force with a simple and small configuration can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an overall configuration of a projection device according to the present invention.

FIG. 2 is a perspective view showing a configuration of a digital audio reproducing device according to the present invention.

FIG. 3 is a front view showing a configuration of a digital audio reproducing device according to the present invention.

FIG. 4 is a sectional view showing a mounted state of a brake unit.

FIG. 5 is a perspective view showing an external configuration of a brake unit.

FIG. 6 is a sectional view showing an internal configuration of a brake unit.

FIG. 7 is a perspective view for describing fixing of a brake unit.

FIG. 8 is a cross-sectional view illustrating a configuration of a position regulating guide.

FIG. 9 is a cross-sectional view illustrating a configuration of a frequency generator.

FIG. 10 is a perspective view showing a configuration of a frequency generator unit.

FIG. 11 is a partial front view showing an installation state of a photo sensor.

FIG. 12 is a block diagram showing a configuration of an optical reading unit.

FIG. 13 is a perspective view showing a configuration of a base cabinet.

FIG. 14 is a side view showing a method of attaching a film traveling system.

FIG. 15 is a perspective view showing a method of housing a circuit board.

FIG. 16 is a plan view showing a movie film.

FIG. 17 is a schematic diagram showing a digital audio track of a movie film.

FIG. 18 is a side view showing a conventional projection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Film film, 13 ... Projector, 29 ... Speaker, 51 ... Digital sound reproducing device unit, 60 ... Sprocket, 70 ... Optical reading unit, 71 ... Emitting unit, 7
2 ... Light receiving section, 75 ... Frequency generator section, 75A ...
Frequency generating cylinder, 90 ... Brake unit, 150 ... Base cabinet, 150A ... Base surface unit, 180 ...
... Photo sensor, 200... Position control guide.

Claims (3)

[Claims] 1. A belt which is pulled in a longitudinal direction by a predetermined traveling drive source is engaged with a roller means, and a braking force is applied to the roller means when the roller means rotates as the belt travels. In the braking device for applying a predetermined tension to the belt-shaped body between the traveling drive source and the roller means, a rotating unit fixed to the roller means and rotating together with the roller means, A braking device, comprising: a fixed fixed portion; and a magnetic field generating means provided on the rotating portion and the fixed portion, respectively, for applying a braking force to the rotating portion rotating with respect to the fixed portion. 2. The braking device according to claim 1, wherein said braking device is housed inside said roller means. 3. A braking device according to claim 1, wherein said belt-like body is a movie film, and said roller means is a sprocket having a projection engaged with a perforation of said movie film. .