KR19990012369A - Head Drum Assembly of Tape Recorder - Google Patents

Abstract

The present invention discloses a head drum assembly of a tape recorder. According to an aspect of the present invention, there is provided an upper drum including a boss having a shaft hole at a lower surface thereof, a receiving groove formed at an upper surface thereof, and an extraction hole formed at a top thereof to allow a wire connected to the video head to be drawn out to an upper portion of the receiving groove; A shaft mounted by the upper and lower bearings to protrude into the shaft hole of the upper drum; A preload boss mounted on the top of the shaft to preload the upper bearing; A table mounted to the upper end of the shaft; A lower drum in which a boss is formed with a shaft hole in the center so that the shaft is press-fitted, and an upper portion of the receiving groove is covered by the upper drum to form a cavity; An amplifier installed in the accommodating groove of the upper drum to amplify the electric signal; A first photo coupler comprising a light emitting unit for converting and outputting an electrical signal input from an amplifier into an optical signal and a light receiving unit for converting and outputting an optical signal into an electrical signal; A second photo is composed of a light emitting unit for converting the input electrical signal into an optical signal to output to the light receiving unit of the first photo coupler and a light receiving unit for converting and outputting the optical signal input from the light emitting unit of the first photo coupler into an electrical signal It includes a coupler.

Therefore, since the video signal is accurately transmitted by the digital method and crosstalk and loss of the signal are effectively prevented, the recording and reproducing characteristics are remarkably improved and the reliability of the product is improved. In addition, since the structure and structure are simply improved, the fabrication and assembly process is easy and simple, and not only the assemblability of the product is improved but also the production cost of the product is remarkably reduced. In addition, since a drum motor is installed in the cavity between the upper drum and the lower drum, it is possible to easily reduce the size and weight of the product.

Description

Head Drum Assembly of Tape Recorder

TECHNICAL FIELD The present invention relates to a tape recorder, and more particularly, to a head drum assembly of a tape recorder in which a video signal of a head drum assembly is transmitted by a digital type.

In general, a tape recorder such as a video cassette recorder (VCR) or a camcorder (recorder) records video and audio signals on a tape of a cassette running along a certain driving path of the odometer by rotating the head drum assembly. Or play it back.

One example of such a head drum assembly of a conventional tape recorder will be described with reference to FIG. 1. The head drum assembly includes an upper drum 10 and a lower drum 11 on the shaft 12. It is mounted at the bottom respectively. At this time, the upper drum 10 is press-fitted to the shaft 12 and mounted, and the lower drum 11 is supported and mounted by two bearings 13.

In addition, the space between the upper drum 10 and the lower drum 11 is interposed so that a rotor and stator transformer 14 and 15 for transmitting signals maintain a constant air gap therebetween. do. Meanwhile, two or more video heads 16 are assembled on the lower surface of the upper drum 10, and a drum motor 20 is installed below the lower drum 11. 20 is composed of a rotor 21 and a stator 22.

Therefore, while the upper drum 10 is rotated in response to the drum motor 20 being driven, the recording or reproducing of video and audio signals is performed by the action of the video head 16.

However, the head drum assembly of the conventional tape recorder as described above has a problem in that recording and reproducing characteristics are degraded because the rotor and stator transformers 14 and 15 transmit signals in an analog type. For example, not only cross talk occurs between the channels of the rotor and the stator transformers 14 and 15, but also a large signal loss occurs so that recording and reproducing characteristics are significantly degraded.

In addition, the rotor and stator transformers 14 and 15 act as an increase factor of the production cost due to difficulties in processing technology, and the rotor and stator transformers 14 are disposed in the space between the upper drum 10 and the lower drum 11. Since it is necessary to interpose (15), the configuration and structure thereof become complicated, and the manufacturing and assembly processes of the upper and lower drums 10 and 11 become cumbersome and complicated.

In particular, since high precision is required in order to maintain the voids of the rotor and stator transformers 14 and 15 in the assembly process of the head drum assembly, there is a problem of lowering the yield of the product. This problem is more serious in the structure of the head drum assembly because a plurality of channels must be formed on opposite surfaces of the rotor and the stator transformer in the head drum assembly employing the multi-channel, such as the four-head method. On the other hand, since the drum motor 20 is installed at the lower portion of the lower drum 11 to produce a large size of the head drum assembly, there is a problem that the product is reduced in size and weight.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a head drum assembly of a tape recorder in which a video signal is transmitted digitally to improve product reliability. .

Another object of the present invention is to improve the assembly and structure of the tape recorder is simple and easy to manufacture and assembly process, as well as to improve the assembly of the product, the production cost of the product is reduced to the head drum assembly of the tape recorder To provide.

It is still another object of the present invention to provide a head drum assembly of a tape recorder, which makes it possible to easily miniaturize and lighten the product.

1 is a cross-sectional view showing a head drum assembly of a conventional tape recorder;

2 is a cross-sectional view showing the head drum assembly of the tape recorder according to the present invention;

3 is a plan view showing the head drum assembly of the tape recorder according to the present invention;

4 is a block diagram showing a head drum assembly of the tape recorder according to the present invention;

5 is a cross-sectional view showing an embodiment of the head drum assembly of the tape recorder according to the present invention.

♣ Explanation of symbols for the main parts of the drawing ♣

30; Upper drum 34; Video head

40; Axes 41,42; Upper and lower bearing

50; Lower drum 55; Amplifier

45; Preload boss 47; Table

60; A first photo coupler 65; 2nd photo coupler

70; A recording and reproducing processor 75; Drum motor

A feature of the present invention for achieving the above object is a head drum assembly of a tape recorder for recording or reproducing video and audio signals on a tape traveling along a certain running path of a traveling system, wherein a boss is formed in the center of a lower surface of a shaft hole. An upper drum formed to have an upper surface thereof, and having an accommodation groove formed on an upper surface thereof, at least two video heads assembled at an edge of the lower surface thereof, and an outlet hole formed to enable the wire connected to the video head to be drawn out to an upper portion of the accommodation groove; A shaft mounted to be supported by the upper and lower bearings so that its upper end protrudes into the shaft hole of the upper drum; A preload boss mounted on the top of the shaft to preload the upper bearing; A table mounted to the upper end of the shaft; A lower drum in which a boss is formed in the center to have a shaft hole so that the shaft is press-fitted, and an upper portion of the receiving groove formed on the upper surface thereof is covered by the upper drum to form a cavity; An amplifier installed in the accommodating groove of the upper drum to amplify the electric signal and connected to the video head by a wire through a lead hole of the upper drum; Two or more first ports are provided on the upper surface of the amplifier so as to correspond to each other and include a light emitting unit for converting and outputting an electrical signal input from the amplifier into an optical signal and a light receiving unit for converting and outputting the optical signal into an electrical signal. With a coupler; A light emitting unit installed on the upper surface of the table so as to correspond to the first photo coupler, converting an electric signal into an optical signal and outputting the light signal to the light receiving unit of the first photo coupler, and an optical signal input from the light emitting unit of the first photo coupler The head drum assembly of the tape recorder including two or more second photo coupler composed of a light receiving unit for converting the output into an electrical signal.

Hereinafter, one preferred embodiment of a head drum assembly of a tape recorder according to the present invention will be described in detail with reference to the accompanying drawings.

2 to 4 are diagrams for explaining the head drum assembly of the tape recorder according to the present invention.

First, as shown in FIG. 2, the head drum assembly is formed such that a boss 31 has a shaft hole 32 at the center of the lower drum 30, and a receiving groove is formed at the upper surface of the upper drum 30. 33) is formed in an approximately recessed shape with an open top. Two or more video heads 34 are assembled on the lower edge of the upper drum 30, and the lead holes 35 are formed on the lower surface of the upper drum 30 so as to be adjacent to the video head 34.

Then, a wire 36 connected to the video head 34 through the lead hole 35 of the upper drum 30 is led out to the upper portion of the receiving groove 33, and the shaft hole of the upper drum 30 32 is fitted to the upper part of the shaft 40 and supported by the upper and lower bearings 41 and 42. At this time, the upper end of the shaft 40 is assembled to protrude to the upper portion of the upper drum 30, the shaft 40 is formed to have a hollow (40A) in the center.

A preload boss 45 for preloading the upper bearing 41 is mounted on the upper portion of the shaft 40, and an elastic deformation is formed between the upper bearing 41 and the preload boss 45. A possible plate spring 46 is interposed and a table 47 is mounted at the upper end of the shaft 40. The plate spring 46 absorbs vibration and shock generated in the axial direction of the upper drum 30 by elastic deformation and imparts stable preload to the upper bearing 41.

On the other hand, the lower drum 50 is mounted to the lower portion of the upper drum 30, the boss 51 is formed on the upper surface in the center of the lower drum 50 to have a shaft hole 52, the lower drum 50 Of the shaft holes 52 are press-fitted into the substantially lower portion of the shaft 40.

The lower drum 50 is mounted on the upper surface of the boss 51 so that the lower bearing 42 is supported, and the boss 51 has a bearing seat 51A that can support the lower bearing 42. It is formed into a truncated cone. At this time, the lower bearing 42 is supported by the bearing seat 51A of the boss 51 to receive a preload.

In addition, the receiving groove 53 is formed in the upper surface of the lower drum 50 in an approximately recessed shape with an upper opening, and the receiving groove 53 of the lower drum 50 is covered by the upper drum 30 to form an upper drum ( A cavity 54 is formed between 30 and the lower drum 50.

In addition, an amplifier 55 is installed on the upper surface of the upper drum 30 so as to correspond to the video head 34. The amplifier 55 amplifies and outputs an input electric signal, and the amplifier 55 is connected to the video head 34 by a wire 36 through the lead hole 35 of the upper drum 30. On the other hand, two or more first photo couplers 60 are provided on the upper surface of the amplifier 55 so as to correspond to the video heads 34. That is, the first photo coupler 60 is provided with numbers corresponding to the video head 34.

The first photo coupler 60 includes a light emitting part 61 for converting an electric signal into an optical signal and outputting the light signal, and a light receiving part 62 for receiving an optical signal and converting the light signal into an electrical signal. The light emitting part 61 and the light receiving part 62 of the 60 are configured to be positioned above and below. Here, the light emitting unit 61 of the first photo coupler 60 converts an electrical signal input from the amplifier 55 into an optical signal, that is, a digital signal, and outputs the light signal. The signal is converted into a signal and input to the amplifier 55.

Two or more second photo couplers 65 are installed on the upper surface of the table 47 so as to correspond to the first photo coupler 60. The second photo coupler 65 is composed of a light emitting unit 66 for converting and outputting an electrical signal into an optical signal, and a light receiving unit 67 for receiving and converting an optical signal into an electrical signal.

At this time, the light emitting portion 66 of the second photo coupler 65 is the light receiving portion 62 of the first photo coupler 60 and the light receiving portion 67 of the second photo coupler 65 is the first photo coupler 60. The light emitting portion 61 is configured to face each other. That is, the second photo coupler 65 is configured such that the light emitting portion 66 and the light receiving portion 67 are positioned at the upper and lower sides of the first photo coupler 60 so as to face the light emitting portion 61 and the light receiving portion 62. do.

Further, the second photo coupler 65 is formed in a substantially semi-circular shape, and the center of the second photo coupler 65 is mounted so as to be positioned on the vertical line of the video head 34. This second photo coupler 65 is preferably assembled to form a circle when two video heads 34 are employed in a two-head manner, for example. Then, the light emitting portion 66 and the light receiving portion 67 of the second photo coupler 65 are connected to the recording and reproducing processing portion 70 by the wire 68 through the hollow 40A of the shaft 40.

On the other hand, a drum motor 75 for rotating the upper drum 30 is provided in the cavity 54 formed between the upper drum 30 and the lower drum 50. The drum motor 75 is composed of a rotor 76 mounted on the lower surface of the upper drum 30, and a stator 77 mounted on the receiving groove 53 of the lower drum 50.

As shown in FIG. 5, the head drum assembly of the present invention is further provided with a bracket 80 outside the upper and lower drums 30 and 50. An extension portion 81 is formed so as not to interfere with the upper drum 30 toward the center of the shaft 40 at the upper end of the bracket 80, and the lower portion of the bracket 80 is decked by the screw 82. It is fixed to the top of (deck: 83).

Thus, the light emitting portion 66 and the light receiving portion 67 of the second photo coupler 65 are connected to the recording and reproducing processing portion 70 by a wire 85 wired using the bracket 80. As such, when the wire 85 is wired by the bracket 80, the hollow 40A may not be formed in the center of the shaft 40.

Referring to the operation of the head drum assembly of the tape recorder according to the present invention as described above are as follows.

First, as shown in FIG. 2 and FIG. 4, the recording state of the video signal is explained. In addition, the rotor 76 is rotated by the driving of the drum motor 70, and the upper drum 30 is centered on the shaft 40. It rotates by the support of the upper and lower bearings 41 and 42.

In this state, when the electrical signal is input from the recording and reproducing processing unit 70 to the light emitting unit 66 of the second photo coupler 65, the light emitting unit 66 of the second photo coupler 65 receives the input electrical signal. The all-optical conversion method converts an optical signal, that is, a digital signal, and outputs the digital signal.

The optical signal output by the light emitter 66 of the second photo coupler 65 is received by the light receiver 62 of the first photo coupler 60, and the light receiver 62 of the first photo coupler 60 is input. The optical signal is converted into an electrical signal by a photoelectric conversion method and output. The electrical signal output from the light receiving unit 62 of the first photo coupler 60 is input to the amplifier 55, and the amplifier 55 amplifies the input electrical signal and inputs it to the video head 34. The video head 34 records the video signal on the tape T according to the electrical signal input from the amplifier 55.

On the other hand, when the reproduction state of the video signal is explained, an electrical signal is output from the tape T by a scan of the video head 34, and the electrical signal of the video head 34 is input to the amplifier 55. do. The amplifier 55 amplifies the input electrical signal and inputs it to the light emitting unit 61 of the first photo coupler 60. The light emitting unit 61 of the first photo coupler 60 receives the input electrical signal as an optical signal. Convert to and print it out.

In addition, the optical signal output from the light emitting portion 61 of the first photo coupler 60 is input to the light receiving portion 67 of the second photo coupler 65, the light receiving portion 67 of the second photo coupler 65 The input optical signal is converted into an electrical signal and input to the recording and reproducing processor 70 to reproduce the video signal.

As described above, the present invention records and reproduces the video signal accurately and digitally by the driving of the amplifier 55 and the first and second photo couplers 60 and 65, thereby effectively preventing crosstalk and signal loss. Significantly improved properties improves product reliability.

On the other hand, the use of the first and second photo coupler 60, 65 not only improves the configuration and structure, but also facilitates and simplifies the fabrication and assembly process, thereby improving the assembly of the product.

That is, the present invention eliminates the need for the rotor and stator transformers 14 and 15, which are conventionally used for the transmission of video signals, thereby improving the assemblability of the product, and compared to the cost of the rotor and stator transformers 14 and 15. Due to the use of relatively inexpensive first and second photo couplers 60 and 65, the production cost of the product is significantly reduced. In addition, since the drum motor 75 is provided in the cavity 54 between the upper drum 30 and the lower drum 50 by a simple structure and structure, it is possible to easily reduce the size and weight of the product.

As shown in FIG. 5, the light emitting portion 66 and the light receiving portion 67 of the second photo coupler 65 are connected to each other using a bracket 80 provided outside the upper and lower drums 30 and 50. 85 to the recording and reproducing processor 70 suitably design and layout the deck 83 and related components, such as no need to form a hollow 40A in the center of the shaft 40. You can change it. In the present invention, the same effect can be obtained even in a multi-channel such as a four-head system.

On the other hand, the above embodiments are merely described one preferred embodiment of the present invention, the scope of application of the present invention is not limited to these, and can be changed as appropriate within the scope of the same idea. For example, the shape and structure of each component specifically shown in the embodiment of the present invention can be modified.

As described above, according to the head drum assembly of the tape recorder according to the present invention, since the video signal is accurately transmitted digitally and effectively prevents crosstalk and signal loss, the recording and playback characteristics are remarkably improved to improve the product quality. Reliability is improved. In addition, since the structure and structure are simply improved, the fabrication and assembly process is easy and simple, and not only the assemblability of the product is improved but also the production cost of the product is remarkably reduced. In addition, since a drum motor is installed in the cavity between the upper drum and the lower drum, it is possible to easily reduce the size and weight of the product.

Claims (8)

A head drum assembly of a tape recorder for recording or reproducing video and audio signals on a tape traveling along a certain driving path of an odometer, The boss 31 is formed in the center of the lower surface to have a shaft hole 32, the receiving groove 33 is formed on the upper surface, two or more video heads 34 are assembled on the lower edge, the video head 34 An upper drum (30) having a withdrawal hole (35) formed therein so that a wire (36) connected to the wire (36) can be drawn out to an upper portion of the receiving groove (33); A shaft (40) mounted on the shaft hole (32) of the upper drum (30) so as to be supported by upper and lower bearings (41) (42) such that its upper end protrudes; A preload boss (45) mounted on an upper portion of the shaft (40) to apply a preload to the upper bearing (41); A table (47) mounted to the upper end of the shaft (40); The boss 51 is formed in the center to have the shaft hole 52 so that the shaft 40 is press-fitted, and the upper portion of the receiving groove 53 formed on the upper surface of the shaft 40 is covered by the upper drum 30 so that the cavity ( A lower drum 50 in which 54 is formed; It is installed in the receiving groove 53 of the upper drum 30 to amplify an electrical signal, and is connected to the video head 34 by the wire 36 through the extraction hole 35 of the upper drum 30. An amplifier 55; The upper surface of the amplifier 55 is installed so as to correspond to each other and the video head 34, the light emitting unit 61 and the light signal to convert the electrical signal input from the amplifier 55 into an optical signal and output the electrical signal Two or more first photo couplers 60, each of which includes a light receiving unit 62 for outputting the converted light; The upper surface of the table 47 is installed so as to correspond to each other with the first photo coupler 60, the light emission to convert the input electrical signal into an optical signal to output to the light receiving portion 62 of the first photo coupler 60 Two or more second photo couplers 60 comprising a portion 66 and a light receiving portion 67 for converting and outputting an optical signal input from the light emitting portion 61 of the first photo coupler 60 into an electrical signal. Head drum assembly of a tape recorder comprising a. The head drum assembly of a tape recorder according to claim 1, wherein a plate spring (46) capable of elastic deformation is interposed between the upper bearing (41) and the preload boss (45). The tape according to claim 1, wherein the boss (51) of the lower drum (50) is formed in a substantially conical truncated shape having a bearing seat (51A) so that the lower bearing (42) is supported and subjected to a preload. Head drum assembly of the recorder. The light emitting portion 66 and the light receiving portion 67 of the second photo coupler 65 are recorded by the wire 68 through a hollow 40A formed at the center of the shaft 40. Head drum assembly of the tape recorder, characterized in that connected to the playback processing unit (70). 5. The head drum assembly of a tape recorder according to claim 1 or 4, wherein the second photo coupler (65) is formed in a substantially semicircular shape. 6. The center of the second photo coupler (65) is mounted so as to be positioned on a vertical line of the video head (34), and the second photo coupler (65) is provided with two video heads (34). Head assembly of a tape recorder, characterized in that it is assembled in a circular case. According to claim 1, A drum motor 75 for rotating the upper drum 30 is installed in the cavity 54 formed between the upper drum 30 and the lower drum 50 and the drum motor ( The head of the tape recorder 75 is composed of a rotor 76 mounted on the lower surface of the upper drum 30 and a stator 77 mounted on the receiving groove 53 of the lower drum 50. Drum assembly. The upper and lower drums 30 and 50 of the bracket 80 is further provided, the light emitting portion 66 of the second photo coupler 65 in the bracket 80 A head drum assembly of a tape recorder, characterized in that a wire (84) connecting the light receiving portion (67) to the recording and reproduction processing portion (70) is wired.