JP3341437B2 - Rotating head drum device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head drum device most suitable for use in a magnetic recording / reproducing apparatus such as a video tape recorder or a digital tape recorder, and more particularly to a rotary head drum mounted on a chassis. It is.

[0002]

[Prior art]

From the video tape recorder General Summary Description Conventionally, as shown in FIG. 5, the video tape recorder of M-type loading system, in the direction of arrow a rotary head drum 2 with respect to the vertical reference P ₁ on the chassis 1 It is installed at a predetermined angle.

After the tape cassette 5 is mounted horizontally on the pair of left and right reel stands 3 and 4 on the chassis 1, the tape cassette 5 is wound around the outer periphery of the pair of left and right tape reels 6 and 7 in the tape cassette 5. The magnetic tape 8 is pulled out horizontally in front of the tape cassette 5 by a pair of left and right main loading means 11a and 11b having a pair of left and right movable inclined guides 9 and a movable vertical guide 10, and is wound around the outer circumference of the rotary head drum 2 by a predetermined amount. Load into a spiral M-shape at the corner.

At this time, the magnetic tape 8 is horizontally pulled out to the left and right sides in front of the tape cassette 5 by a pair of left and right subloading means 12a and 12b composed of a tape tension regulator and the like, and the supply side 8a of the magnetic tape 8 is drawn. A channel erase head 15 and an audio recording / reproducing head 16 are loaded on the full width erasing head 13 and a plurality of vertical guides 14 installed at a fixed position, and the winding side 8b of the magnetic tape 8 is set at a fixed position. ,
A plurality of fixed heads such as a confi head 17, a capstan 18 and a plurality of vertical guides 19 are loaded.

After the tape is loaded, the take-up side 8b of the magnetic tape 8 is pressed against the capstan 18 by the pinch roller 20, and the magnetic tape 8 is supplied from the supply-side tape reel 6 to the take-up side tape reel 7. The video signal is recorded and reproduced on the magnetic tape 8 by the rotary head drum 2 while running at a constant speed along the loading path for winding.

[Description of Conventional Rotary Head Drum Apparatus] As shown in FIGS.
Is composed of a lower drum 200 as a fixed drum and an upper drum 201 as a rotating drum. Then, a plurality of rotary heads 2
02 is attached, the tape lead 203 is formed at a predetermined helix angle theta ₁ to the outer periphery of the lower drum 200 is a spiral upward stepped portion.

An upper drum 201 is fixed to the outer periphery of the upper end of a spindle 204 rotatably attached to the center of the lower drum 200. The upper drum 201 is attached to the lower periphery of the lower drum 200 at the outer periphery of the lower end of the spindle 204. A spindle motor 205 for rotationally driving the motor is mounted.

As shown in FIGS. 6 and 7, a predetermined direction (arrow a in FIG. 5) is
A substantially annular drum mounting surface 22 that is inclined in the direction (direction) is formed. On the drum mounting surface 22, two reference pins 23 and 24, which are positioning references, are formed at 180 ° intervals, and three female screws are formed. Holes 25 are formed at 120 ° intervals.

On the other hand, as shown in FIGS. 6 and 7, a lower end surface 20 which is a lower portion of the lower drum 200 of the rotary head drum 2 is provided.
Two positioning holes 26 and 27, which are portions to be positioned, are formed at 180 ° intervals at the outer peripheral position 0a and the like. In addition,
One positioning hole 26 is formed in a perfect circle having the same diameter as the reference pin 23, and the other positioning hole 27 is formed in the reference pin 24.
It is formed in a long hole having the same diameter as that of the lower drum 200 and extending long in the radial direction of the lower drum 200. Further, three screw insertion holes 29 are formed at 120 ° intervals on three projections 28 integrally formed on the outer periphery of the lower end of the lower drum 200.

Then, the two positioning holes 26 and 27 of the lower drum 200 are inserted into the two reference pins 23 and 24 from above, and the lower end surface 200a of the lower drum 200 is
And the three screw insertion holes 29
By screwing the three setscrews 30 inserted from above into the three female screw holes 25 of the drum mounting surface 22 and fastening the same, the lower drum 200 moves the rotary head drum 2 onto the chassis 1 at a predetermined inclination angle. Screwed on.

Then, the circumferential phase of the lower drum 200 on the chassis 1 is set by the reference pins 23, 24 and the positioning holes 26, 27, and the height of the tape lead 203 with respect to the horizontal reference is set.

On the other hand, as shown in FIG. 5, the magnetic tape 8 loaded on the outer periphery of the rotary head drum 2 in a helical M-shape at a predetermined winding angle is formed on the lower drum 200 and the upper drum 200 of the rotary head drum 2. Wound over the drum 201.

Then, the tape lead 2 with respect to the horizontal reference
If the height of the magnetic tape 03 is set correctly, a stable tape running that allows the lower edge 8c of the magnetic tape 8 to run correctly along the tape lead 203 is obtained.

[Relationship between Conventional Processing of Positioning Hole and Tape Running System] Conventionally, as shown in FIG. 7, the tape lead 203 is moved to a reference position P ₂ with reference to the lower end surface 200 a of the lower drum 200 and the like. While processing at a predetermined spiral angle θ ₁ so as to be the reference height H ₁ , while positioning holes 26,
27 are processed in the phase angle theta ₂ of the relative angular position P ₃ with respect to the reference position P ₂ a. Then, the reference height H ₁ of the tape lead 203 and the phase angle θ _{2 of the} positioning holes 26 and 27 are set.
Were managed independently of each other.

[0015]

Therefore, the conventional rotary head drum device has the reference height H ₁ of the tape lead 203.
It is necessary to control the phase angle θ ₁ of the positioning holes 26 and 27 with tight tolerances.
In addition, there is a problem that a large amount of labor and time are required for processing the positioning holes 26 and 27, productivity is low, and processing cost is high.

On the other hand, in the conventional rotary head drum device, although the spiral angle θ ₁ of the tape lead 203 can be set with high accuracy, the reference height H ₁ of the tape lead 203 and the phase angle θ ₁ of the positioning holes 26 and 27 can be set. The variations in the processing dimensions were several μm each, and the accumulation of these dimensional tolerances was extremely large.

The accumulation of the dimensional tolerance is determined by the positioning holes 26 inserted into the reference pins 23 and 24 of the chassis 1.
For appearing as variations in reference height H ₁ of the tape lead 203 for 27, as shown in FIG. 8 (B), in the exchange or the like of the rotary head drum 2, the tape lead with respect to the lower edge 8c of the magnetic tape 8 203 will variation of H ₂ height occurs in a stable tape running of the magnetic tape 8 generates a serious problem that can not be obtained.

For this reason, in a conventional rotary head drum device, as shown in FIG. 8C, a pair of left and right movable inclined guides 9 and movable vertical guides 10 in a pair of left and right main loading means 11a and 11b are used. It was necessary to adjust the running height of the magnetic tape 8 in the direction of arrow b so that the height of the lower edge 8c of the magnetic tape 8 was adjusted to the height of the tape lead 203 by fine adjustment.

However, the operation of adjusting the traveling height of the magnetic tape 8 by finely adjusting the pair of the movable inclined guides 9 and the movable vertical guides 10 on the left and right sides requires skill and requires a great deal of labor and time. In addition to significantly increasing the cost, the movable inclined guide 9 and the movable vertical guide 10 are movable guides that can be moved by sliders, respectively. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides a rotary head drum device which can minimize variations in the height of tape leads due to replacement of the rotary head drum. It is intended to be.

[0021]

According to the present invention, there is provided a rotary head drum device according to the present invention, wherein a tape lead is formed in a helical shape on the outer periphery of a lower drum, and a positioning portion is formed on a lower side of the lower drum. When the rotary head drum is mounted on the chassis by the lower drum, the height of the tape lead is determined by positioning the portion to be positioned on the positioning reference on the chassis. In the rotary head drum device configured to be set, when processing the portion to be positioned of the lower drum, a reference height in the tape lead formed in advance on the outer periphery of the lower drum is detected to set a reference position. The position-determined portion is set and processed at a predetermined relative angular position with respect to the reference position.

[0022]

The rotary head drum device of the present invention configured as described above detects the reference height in a tape lead formed in a spiral shape in advance on the outer periphery of the lower drum of the rotary head drum and determines the reference position. Since the set portion was processed at the lower side of the lower drum at a predetermined relative angle position with respect to the above reference position, when the rotating head drum was mounted on the chassis by the lower drum, the lower drum was positioned on the chassis. By positioning to the above positioning reference, the height of the tape lead with respect to the horizontal reference can be accurately set irrespective of variations in the height of the tape lead during processing.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a rotary head drum device in a video tape recorder to which the present invention is applied will be described below with reference to FIGS. The same components as those in FIGS. 5 to 8 are denoted by the same reference numerals, and the description will not be repeated.

[Description of Detecting Device for Reference Height Position of Tape Lead] First, as shown in FIG. 2, the lower drum 2 is inserted into a circular lower drum fitting hole 33 formed at the center of the jig 32 or the like.
The lower end of 00 is fitted from above and mounted by a plurality of projections 28. The lower drum fitting hole 33 is formed to have the same diameter as the lower end of the lower drum 200.
It is configured such that the rotation can be adjusted without rattling in the c 'direction.

The lower drum 200 is placed on the jig 32.
A plurality of lower drum fixing means 34 for fixing the lower drum 200 on the jig 32 by fastening the plurality of projections 28 and the like are attached.

The lower drum 200 is placed on the jig 32.
Optical detection means 35 is provided to detect the reference height H ₃ in the tape lead 203 which is an example of a detecting means for setting a reference position P _4.

Then, as shown in FIG. 3, the optical detecting means 35 includes a laser diode (LD) 3 as a light emitting element.
50, a horizontal direction perpendicular to the axis P ₆ of the lower drum 200 to the irradiation point X on the outer peripheral surface of the lower drum 200 and condenses the light F ₁ emitted from the laser diode 350 to the spotlight 351 and the lower drum 2
A lens 352 for condensing the reflected light F ₂ again spot light reflected by the irradiated point X on the peripheral surface of 20, the semiconductor is a light receiving element for receiving reflected light F ₂ is the spot light-receiving surface 353a And a position detection element (PSD) 353.

At this time, the light F ₁ is irradiated at a reference height H _{3 based} on the lower end surface 200 a of the lower drum 200 and the like.

[Description of Processing Machine for Positioning Hole] Next, FIG.
As shown in FIG. 4, the processing machine 36 is installed below the jig 32, and is positioned through the lower drum fitting hole 34 at the outer peripheral position of the lower end surface 200 a, which is the lower part of the lower drum 200. Two drills 360 as processing means for processing the holes 26 and 27 are provided.

[Method of Detecting Reference Height Position of Tape Lead] First, as shown in FIGS. 2 and 3, a spirally formed tape lead of a lower drum 200 placed on a jig 32 The reference height H ₃ in 203 is detected by the optical detection means 35.

At the time of detection of the reference height H ₃ , the light F ₁ emitted from the laser diode 350 of the optical detection means 35 is spotted by the lens 351 at the irradiation point X on the outer peripheral surface of the lower drum 200. H ₃ , the reflected light F ₂ is condensed into spot light by a lens 352, and the light receiving surface 353 a of the semiconductor position detecting element 353 is received.
To receive light. Then, the lower drum 200 is rotated and adjusted on the jig 32 in the direction of the arrow c or c ', and the tape lead 20 is adjusted.
Search reference height H ₃ in the 0.

That is, when the phase of the lower drum 200 on the jig 32 is, for example, [State 1] shown in FIG. 2A, as shown in [State 1] shown in FIG. , when the reflection point a ₁ of the light f ₁ is a larger-diameter outer peripheral surface 200b below the tape lead 203 of the lower drum 200, the optical axis is f ₁ becomes the reflected light F _2, the reflected light F ₂ is a semiconductor position detector Element 3
53 received by the light receiving position A ₂ of the light receiving surface 353a of the. Then, the height of the tape lead 203 detected at this time becomes the reference height H ₃ + α.

Further, when the phase of the lower drum 200 on the jig 3 is, for example, [state 2] shown in FIG.
As shown in the (B) are shown [state 2], when the reflection point B ₁ of the optical F ₁ is a small diameter outer circumferential surface 200c of the above tape lead 203 of the lower drum 200, the optical axis is reflected light F ₂ f ₂ , and the reflected light F ₂ becomes the semiconductor position detecting element 35
3 is received by the light receiving position B ₂ of the light-receiving surface 353a. Then, the height of the tape lead 203 detected at this time becomes the reference height H ₃ −α.

Then, when the lower drum 200 on the jig 32 is rotationally adjusted in the direction of arrow c or c ', [state 1] in FIG.
As shown by a dashed line in FIG. ₃ , the reflection points of the light F ₁ are A ₁ and B ₁ at the reference height H ₃ in the tape lead 203.
To change between.

If the reflection point of the light F ₁ changes between A ₁ and B ₁ , the light receiving position of the reflected light F ₂ at the semiconductor position detecting element 353 changes between A ₂ and B _2. Accordingly, the semiconductor position detecting element 353 can accurately detect the reference height H ₃ in the tape lead 203 by the change.

At this time, the semiconductor position detecting element 353
Are the electrodes at both ends of the light receiving surface 353a and the received reflected light F ₂
It converted into a current by detecting the distance between the light receiving position A ₂ and B ₂ in.

Then, the semiconductor position of the optical detecting means 35
When the detection element 353 detects the reference height H ₃ in the tape lead 203, as shown in FIG. 1, the lower drum 20
0 the reference position H ₄ on the circumference of, for example, automatically set to a predetermined position of the detection position of the reference height H _3, the detection information of the reference position H ₃ is fed back to the machine 36 .

[Processing of Positioning Holes] First, the lower drum 200 is firmly fixed on the jig 32 by a plurality of lower drum fixing means 34, and then the processing machine 36 is moved to the reference position as shown in FIG. A predetermined relative angle θ _{3 based} on H ₄
Advance on the relative angular position P ₅ which is set is processed exactly two positioning holes 26, 27 in two locations, such as peripheral position of the lower end surface 200a of the lower drum 200.

At this time, as shown in FIGS. 3 and 4,
The processing machine 36 is provided with two positioning holes 26 and 27 at the outer peripheral position of the lower end surface 200a of the lower drum 200 from below the fitting hole 33 into the lower drum of the jig 32 by two drills 360 or the like.
Is processed vertically.

As described above, in the rotary head drum device of the present invention, the optical detecting means 35 detects the reference height H ₃ in the tape lead 203 formed in a spiral shape on the outer periphery of the lower drum 200. Te, set the reference position P _4, on the relative angular position P ₅ which is set in the relative angle theta ₃ the reference position P ₄ as a reference, such as a peripheral position of the lower end surface 200a which is the lower side of the lower drum 200 The two positioning holes 26 and 27 are machined.

Accordingly, irrespective of variations in the height of the tape lead 203 during processing, the dimensional tolerance (variation) of the relative angle θ ₃ in the tape lead 203 with respect to the reference height H ₃ can be extremely reduced.

As a result, as described with reference to FIG. 6, the rotary head drum 2 is mounted on the drum mounting surface 22 of the chassis 1 by the lower end surface 200a of the lower drum 200, and is mounted on the chassis 1 by a plurality of set screws 30. When screwing to
One positioning hole 26, 27 with two reference pins 23, 24
To the lower drum 20 with respect to the chassis 1
By performing the positioning in the circumferential direction of 0, the tape lead with respect to a horizontal reference such as the horizontal height at which the tape cassette 5 is mounted as shown in FIG. the reference height H ₃ of 203 can be accurately set.

[0043] At this time, reference height H ₁ of the conventional tape lead 203 shown in FIG. 7, the tape lead 203 and the position
Variations during machining of the phase angle θ ₁ between the fixing holes 26 and 27
The accumulation of these variations was large at several μm each.
However, the rotary head drum device of the present invention particularly uses the optical detecting means 35 using the semiconductor position detecting element 353 as the detecting means for detecting the reference height H ₃ of the tape lead 203. The variation of the detection value of ₃ is
And can be suppressed only to variations in the diameter of the light F ₁ of the spot light at the irradiation point X of the lower drum 200 shown in FIG. 2, reference reference height H ₁ and the position variation of the detected value of the height H ₃
Determining cumulative bar during processing of the phase angle theta ₁ reference holes 26, 27
It can be much smaller than Ratsuki.

Therefore, as shown in FIG. 8B, the variation in the height H ₂ of the tape lead 203 with respect to the lower edge 8c of the magnetic tape 8 at the time of replacement of the rotary head drum 2 or the like can be made extremely small. This eliminates the need to adjust the running height of the magnetic tape 8 in the direction of arrow b as shown in FIG. 8C every time the rotary head drum 2 is replaced or the like. Fig. 8
The stable tape running of the magnetic tape 8 as shown in FIG.

In the rotary head drum device according to the present invention, since the reference height H ₃ in the tape lead 203 previously formed in a spiral shape on the outer periphery of the lower drum 200 is detected later, the tape the dimensional tolerance of the reference height H ₃ during machining of the lead 203, strictly no need to manage as the reference height H ₁ of the conventional tape lead 203 shown in FIG. 7, the dimensions of the reference height H ₃ it can have a clear (variation in the reference height H ₃ may be larger) in tolerance.

Accordingly, the reference height H of the tape lead 203
_Since the dimensional control of ₃ is easy, the processing of the tape lead 203 becomes easy, and the processing cost can be greatly reduced.

As described above, one embodiment of the present invention has been described.
The present invention is not limited to the embodiments described above, and various modifications can be made based on the technical idea of the present invention.

For example, the loading method of the magnetic tape 8 is not limited to the M-type loading method shown in the embodiment, but may be a U-type loading method.

The position to be processed on the lower drum 200 is not limited to the positioning holes 26 and 27 shown in the embodiment, but may be an uneven fitting structure to the chassis 1 or various marks. .

Therefore, contrary to the embodiment, the reference pins 23,
24 is formed on the lower drum 200 side as a portion to be positioned,
Positioning holes 26 and 27 may be formed on the chassis 1 side.

Further, the positioning holes 26 and 27 are
00, a plurality of projections 2 for screwing.
8 are integrally formed on the outer periphery of the lower end of the lower drum 200, and the two projections are formed with positioning holes 26,
27 can be formed. In this case, the positioning holes 26 and 27 are inserted into the two projections of the lower drum 200.
Can be machined from above.

The detecting means for detecting the reference height H ₃ in the tape lead 203 is not limited to the optical detecting means shown in the embodiment, but may use other various optical and mechanical detecting means. Is possible.

[0053]

The rotary head drum device of the present invention configured as described above has the following effects.

According to a first aspect of the present invention, a reference position is set by detecting a reference height in a tape lead formed in a spiral shape in advance on the outer periphery of a lower drum of the rotary head drum, and the reference position is set at a lower side of the lower drum. By processing the portion to be positioned at a predetermined relative angular position with respect to the position and positioning the portion to be positioned on the lower drum to the positioning reference on the chassis when the rotary head drum is mounted on the chassis by the lower drum, the tape lead The height of the tape lead relative to the horizontal reference can be set accurately irrespective of the variation in the height at the time of processing. It can be made extremely small, and stable tape running can be reproduced.

According to the first aspect, it is not necessary to strictly control the dimensional tolerance of the height when the tape leads are spirally formed on the outer periphery of the lower drum, and the tape leads can be easily processed to improve productivity. Improvement and reduction in processing cost can be achieved.

According to the first aspect, it is possible to reduce the necessity of adjusting the traveling height of the magnetic tape by finely adjusting the movable inclined guide and the movable vertical guide when the rotary head drum is replaced or the like. Easier and lower cost.

According to a second aspect of the present invention, a detecting means for detecting a reference height of the tape lead is provided on a jig on which the lower drum is mounted, and the lower drum is rotated and adjusted in a circumferential direction. Since the detecting means detects the reference height during the tape reading, the reference height during the tape reading can be easily detected.

According to a third aspect of the present invention, after detecting the reference height in the tape lead, the lower drum is fixed on the jig to process the portion to be positioned. Processing of parts can be performed accurately.

According to a fourth aspect of the present invention, since the detecting means is constituted by a light reflection type optical detecting means having a light emitting element and a light receiving element, it is possible to accurately detect the reference height during tape reading.

According to a fifth aspect of the present invention, since the positioning reference of the chassis and the portion to be positioned of the lower drum are constituted by the reference pins and the positioning holes inserted into the reference pins, when the rotary head drum is mounted on the chassis. To
The lower drum can be easily and accurately positioned on the chassis by inserting the positioning holes into the reference pins.

[Brief description of the drawings]

FIG. 1 illustrates a reference height of a tape lead and a relative position of a reference position and a positioning hole when a positioning hole is formed in a lower drum of a rotary head drum device according to an embodiment of the present invention. It is a side view and a bottom view.

FIG. 2 is a perspective view illustrating a method for detecting a reference height of a tape lead in the rotary head drum device of the present invention.

FIG. 3 is a schematic diagram showing details of an optical detecting means in the rotary head drum device of the present invention and a relationship with a processing machine.

FIG. 4 is a perspective view for explaining processing of a positioning hole of a lower drum in the rotary head drum device of the present invention.

FIG. 5 is a schematic plan view illustrating a tape loading device of the video tape recorder.

FIG. 6 is an exploded perspective view illustrating a rotary head drum and a method of mounting the rotary head drum on a chassis.

FIG. 7 shows a conventional method for processing a tape lead of a lower drum,
It is the side view and bottom view explaining the processing method of a positioning hole.

FIG. 8 is a side view for explaining winding of a magnetic tape around a rotary head drum, adjustment of a tape running state, and adjustment of a running height of the magnetic tape.

[Explanation of symbols]

Reference Signs List 1 chassis 2 rotating head drum 200 lower drum 200a lower drum lower surface 200b lower drum outer circumferential surface 200c lower drum outer circumferential surface 201 upper drum 202 rotating head 203 tape lead 205 spindle motor 5 tape cassette 8 magnetic tape 22 drum mounting surface 23 , 24 Reference pin (positioning reference) 25 Female screw hole 26, 27 Positioning hole (position to be positioned) 28 Projection 29 Screw insertion hole 30 Set screw 32 Jig 33 Lower drum fitting hole 34 Drum fixing means 35 Optical detection means 350 Laser diode (light emitting element) 351, 352 Lens 353 Semiconductor position detecting element (light receiving element) 36 Processing machine 360 Drill H ₃ Reference height in tape lead P ₄ Reference position P ₅ Phase angle position θ ₃ Phase angle

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 15/61

Claims (5)

(57) [Claims] 1. A rotating head drum having a tape lead formed in a spiral shape on the outer periphery of a lower drum and a portion to be positioned formed on a lower side of the lower drum, wherein the rotating head drum is formed of a chassis by the lower drum. A rotating head drum device configured to set the height of the tape lead by positioning the portion to be positioned on the positioning reference on the chassis when mounting the device on the chassis; At the time of processing, the reference position is set by detecting a reference height in the tape lead formed in advance on the outer periphery of the lower drum, and the positioning portion is processed at a predetermined relative angular position with respect to the reference position. A rotary head drum device. 2. A detecting means for detecting a reference height of the tape lead is provided on a jig on which the lower drum is mounted, and the lower drum is rotated in a circumferential direction to thereby adjust the detecting means. 2. The rotary head drum device according to claim 1, wherein a reference height during the tape reading is detected. 3. The rotary head drum device according to claim 2, wherein the lower drum is fixed on the jig after the detection of the reference height in the tape lead to process the portion to be positioned. . 4. The rotary head drum device according to claim 1, wherein said detecting means comprises a light reflection type optical detecting means having a light emitting element and a light receiving element. 5. The positioning reference of the chassis and the portion to be positioned of the lower drum are constituted by a reference pin and a positioning hole inserted into the reference pin. The rotary head drum device according to claim 3.