CA1240393A - Tape guide mechanism for a magnetic recording/reproducing apparatus - Google Patents
Tape guide mechanism for a magnetic recording/reproducing apparatusInfo
- Publication number
- CA1240393A CA1240393A CA000488981A CA488981A CA1240393A CA 1240393 A CA1240393 A CA 1240393A CA 000488981 A CA000488981 A CA 000488981A CA 488981 A CA488981 A CA 488981A CA 1240393 A CA1240393 A CA 1240393A
- Authority
- CA
- Canada
- Prior art keywords
- drum
- wrap
- tape
- guide
- point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A tape guide mechanism for a magnetic recording/reproducing apparatus of the invention has a tape guide drum and first and second guide pins. The tape guide drum incorporates a rotary drum, has a lead portion on its outer circumferential surface, and has a rotating axis inclined with respect to a reference surface. The first and second guide pins are arranged at the sides of the tape guide drum so as to wrap a magnetic tape around the drum, and are inclined with respect to the reference surface. The first and second guide pins are arranged such the the magnetic tape enters and exits the drum at elevation angles with respect to the lead portion. The wrap central point of the tape around the tape guide drum is not included in a plane including first and second contact points between the first and second guide pins and the central line of the magnetic tape.
A tape guide mechanism for a magnetic recording/reproducing apparatus of the invention has a tape guide drum and first and second guide pins. The tape guide drum incorporates a rotary drum, has a lead portion on its outer circumferential surface, and has a rotating axis inclined with respect to a reference surface. The first and second guide pins are arranged at the sides of the tape guide drum so as to wrap a magnetic tape around the drum, and are inclined with respect to the reference surface. The first and second guide pins are arranged such the the magnetic tape enters and exits the drum at elevation angles with respect to the lead portion. The wrap central point of the tape around the tape guide drum is not included in a plane including first and second contact points between the first and second guide pins and the central line of the magnetic tape.
Description
~2~0393 P~ACXGROUND OF THE INVENTION
-Field of the Invention:
The present invention relates to a tape guide mechanism for a magnetic recording/reproducing apparatus having a cylindrical guide drum incorporating a rotary head.
Description of the Prior Art:
Fig. 1 schematically shows a tape guide mechanism for a tape guide drum l incorporating a rotary head in a magnetic recording/reproducing apparatus of helical scan type.
The drum l is arranged inclined at a predetermined angle with respect to a reference surface
-Field of the Invention:
The present invention relates to a tape guide mechanism for a magnetic recording/reproducing apparatus having a cylindrical guide drum incorporating a rotary head.
Description of the Prior Art:
Fig. 1 schematically shows a tape guide mechanism for a tape guide drum l incorporating a rotary head in a magnetic recording/reproducing apparatus of helical scan type.
The drum l is arranged inclined at a predetermined angle with respect to a reference surface
2. A magnetic tape 3 is passed from a guide roller 4 through a guide point a of an inclined guide pin 5 and is wrapped around the circumferential surface of the drum l so as to oppose a rotary head. The tape is wrapped through a wrap angle of about 180 from an entrance point b to an exit point-d through a central point c. The magnetic tape 3 is then passed to a guide roller 7 through a guide point e of an inclined guide pin 6. In Fig. l, the respective points a, b, c, d and e are illustrated as points on the central line of the magnetic tape 3 along its widths direction. A tape lead step (not shown) having a lead angle for regulating downward movement of the magnetic tape 3 is formed on the circumferential surface of the drum 1 in a known manner. Ike magnetic tare 3 is Devon on this tape lead step.
In a tape guide mechanism of the type described above, the magnetic tape 3 can be stably #
1:~40393 driven by properly selecting, in accordance with a predetermined equation, the diameter and the inclination angle of the drum 1 with respect to the reference surface 2, the diameter and the inclination angle of the guide pins 5 and 6 with respect to the reference surface 2, the wrap angle of the magnetic tape 3 around the drum 1, i.e., the angle from the point b to the point d, a distance Al between the points a and b, a distance Q2 between the points d and e, and an angle a (lead angle) of the magnetic tape 3 at the point c with respect to a single plane f including the points a, c and e.
Other important conditions for stably driving the magnetic tape 3 are that the heights at the points a, c and e from the reference surface 2 be equal to each other, and the plane f be parallel to the reference surface 2.
In the above tape guide mechanism, the distances Al and Q2 are equal to each other.
Therefore, the guide roller I, the guide pin 5, the guide roller 7, and the guide pin 6 can be symmetrically arranged with respect to the drum 1.
This allows easy design and reduces the overall size of the apparatus.
Thus, although the above-mentioned tape guide mechanism has various advantages as noted above, satisfactory regulation of widths movement of the magnetic tape 3 on the circumferential surface of the drum 1 cannot be obtained. For this reason, the 240;~93 magnetic tape 3 tends to float upward from the tape lead step on the circumferential surface of the drum 1.
In accordance with a technique proposed to overcome this drawback, when the magnetic tape 3 enters from the entrance point b, it is allowed to enter inclined upward by an elevation angle 91 as indicated by a dotted line in Fig. 1. When the magnetic tape 3 is passed through the exit point d, it is guided inclined upward at an elevation angle I as also indicated by a dotted line. A force acts to urge the magnetic tape 3 toward the tape lead step so as to regulate the widths movement of the magnetic tape 3.
This technique is disclosed, for example, in Japanese Patent Disclosure No. 58-121170. With the condition that the plane f is parallel to the reference surface 2, in order to incline the magnetic tape 3 at the angles 31 and e 2 as indicated by the dotted lines in Fig. 1, the guide points a and e must be shifted to drum 1 to positions indicated by the-dotted lines in Fig. 1. me That is, the guide pin 5 must be moved closer to the drum 1 and the guide pin 6 must be moved away from the drum 1 to positions indicated by the dotted lines. The angles at and I are normally small angles, e.g., 1.0 to 1.5. However, the corresponding moving distances of the guide pins 5 and 6 are relatively large. In this case, if the wrap angle of the magnetic tape 3 around the drum 1 is large, e.g., 180 or more, no problem occurs. However, if the wrap angle is small, e.g., about 90, the moving distance of the guide pin 6 is set to be several to several tens of times that of 24039;3 the guide pin I Thus, when the point a is moved on the plane f, if it is moved a small distance to the point a, the tape is inclined upward by the angle I
However, when the point e is moved on the plane f, the magnetic tape 3 is not inclined upward by the angle a unless the point e is moved a long distance to the point en.
As a result, as shown in Figs. 2 and 3, the distance Q2 is rendered far larger than the distance Al (in the illustrated example, Q2 i 4Q1) Then the arrangement of the guide roller 4 and the guide pin 5, and the guide roller 7 and the guide 6 becomes non symmetrical with respect to the drum 1. A
difficulty occurs in mechanism design, and prevents the manufacture of a compact apparatus.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a tape guide mechanism for a magnetic recording/reproducing apparatus wherein inclined guide pins at entrance and exit of a drum can be arranged at points most preferable in terms of design when a magnetic tape enters the drum at an elevation angle end exits at an elevation angle a.
It is another object of the present invention to provide a tape guide mechanism for a magnetic recoxding/reproducing apparatus, capable of regulating widths movement of the magnetic tape along the circumferential surface of the drum.
It is still another object of the present invention to provide a tape guide mechanism for a 12~L0;~93 magnetic recordlng/repro~ucing apparatus wherein guide pins at drum entrance and exit can be arranged symmetrically with respect to the drum.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic side view showing an embodiment of the present invention and for explaining a conventional mechanism;
Fig. 2 is a perspective view of a tape guide mechanism wherein the tape is guided at an elevation angle;
Fig. 3 is a schematic plan view of the mechanism shown in Fig. 2;
Fig. 4 is a graph showing the distance from the inclined guide pins at the entrance and exit to the drum as a function of the moving distance of the tape wrap central position; and Fig. 5 is a schematic plan view showing an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, assume that the point a is shifted to the point at to incline the magnetic tape
In a tape guide mechanism of the type described above, the magnetic tape 3 can be stably #
1:~40393 driven by properly selecting, in accordance with a predetermined equation, the diameter and the inclination angle of the drum 1 with respect to the reference surface 2, the diameter and the inclination angle of the guide pins 5 and 6 with respect to the reference surface 2, the wrap angle of the magnetic tape 3 around the drum 1, i.e., the angle from the point b to the point d, a distance Al between the points a and b, a distance Q2 between the points d and e, and an angle a (lead angle) of the magnetic tape 3 at the point c with respect to a single plane f including the points a, c and e.
Other important conditions for stably driving the magnetic tape 3 are that the heights at the points a, c and e from the reference surface 2 be equal to each other, and the plane f be parallel to the reference surface 2.
In the above tape guide mechanism, the distances Al and Q2 are equal to each other.
Therefore, the guide roller I, the guide pin 5, the guide roller 7, and the guide pin 6 can be symmetrically arranged with respect to the drum 1.
This allows easy design and reduces the overall size of the apparatus.
Thus, although the above-mentioned tape guide mechanism has various advantages as noted above, satisfactory regulation of widths movement of the magnetic tape 3 on the circumferential surface of the drum 1 cannot be obtained. For this reason, the 240;~93 magnetic tape 3 tends to float upward from the tape lead step on the circumferential surface of the drum 1.
In accordance with a technique proposed to overcome this drawback, when the magnetic tape 3 enters from the entrance point b, it is allowed to enter inclined upward by an elevation angle 91 as indicated by a dotted line in Fig. 1. When the magnetic tape 3 is passed through the exit point d, it is guided inclined upward at an elevation angle I as also indicated by a dotted line. A force acts to urge the magnetic tape 3 toward the tape lead step so as to regulate the widths movement of the magnetic tape 3.
This technique is disclosed, for example, in Japanese Patent Disclosure No. 58-121170. With the condition that the plane f is parallel to the reference surface 2, in order to incline the magnetic tape 3 at the angles 31 and e 2 as indicated by the dotted lines in Fig. 1, the guide points a and e must be shifted to drum 1 to positions indicated by the-dotted lines in Fig. 1. me That is, the guide pin 5 must be moved closer to the drum 1 and the guide pin 6 must be moved away from the drum 1 to positions indicated by the dotted lines. The angles at and I are normally small angles, e.g., 1.0 to 1.5. However, the corresponding moving distances of the guide pins 5 and 6 are relatively large. In this case, if the wrap angle of the magnetic tape 3 around the drum 1 is large, e.g., 180 or more, no problem occurs. However, if the wrap angle is small, e.g., about 90, the moving distance of the guide pin 6 is set to be several to several tens of times that of 24039;3 the guide pin I Thus, when the point a is moved on the plane f, if it is moved a small distance to the point a, the tape is inclined upward by the angle I
However, when the point e is moved on the plane f, the magnetic tape 3 is not inclined upward by the angle a unless the point e is moved a long distance to the point en.
As a result, as shown in Figs. 2 and 3, the distance Q2 is rendered far larger than the distance Al (in the illustrated example, Q2 i 4Q1) Then the arrangement of the guide roller 4 and the guide pin 5, and the guide roller 7 and the guide 6 becomes non symmetrical with respect to the drum 1. A
difficulty occurs in mechanism design, and prevents the manufacture of a compact apparatus.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a tape guide mechanism for a magnetic recording/reproducing apparatus wherein inclined guide pins at entrance and exit of a drum can be arranged at points most preferable in terms of design when a magnetic tape enters the drum at an elevation angle end exits at an elevation angle a.
It is another object of the present invention to provide a tape guide mechanism for a magnetic recoxding/reproducing apparatus, capable of regulating widths movement of the magnetic tape along the circumferential surface of the drum.
It is still another object of the present invention to provide a tape guide mechanism for a 12~L0;~93 magnetic recordlng/repro~ucing apparatus wherein guide pins at drum entrance and exit can be arranged symmetrically with respect to the drum.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic side view showing an embodiment of the present invention and for explaining a conventional mechanism;
Fig. 2 is a perspective view of a tape guide mechanism wherein the tape is guided at an elevation angle;
Fig. 3 is a schematic plan view of the mechanism shown in Fig. 2;
Fig. 4 is a graph showing the distance from the inclined guide pins at the entrance and exit to the drum as a function of the moving distance of the tape wrap central position; and Fig. 5 is a schematic plan view showing an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, assume that the point a is shifted to the point at to incline the magnetic tape
3 upward at the elevation angle 31' and that the point e is shifted to the point of to incline the magnetic tape 3 upward by the elevation angle 32. In this case, if the point c is moved downward by a distance Q3 while the points at and of are on the plane f, it was found by the present inventors that the distances Al and Q2 change as shown in Fig. 4. Therefore, when a distance Q3' satisfying the condition Al = Q2 is calculated in accordance with Fig. 4 and the point c is 12~0393 shifted to the point at, the distance Al between the points a and b can be set to be equal to the distance Q2 between the points d and en, as shown in Fig. S.
With the above arrangement, the guide roller
With the above arrangement, the guide roller
4 and the guide pin 5, and the guide roller 7 and the guide pin 6 can be set to be symmetrical about the drum 1. Note that Fig. 4 is a graph showing the characteristics for improving the relationship between the distances Al and Q2~ i.e., the relation Q2 -~4Q1 Referring to Fig. 4, when Q3 = I Q2 Jo 4Q1' According to the above embodiment, Q1 = Q2.
However, in general, when the distance Q3 is selected, the distances Q1 and Q2 can be freely selected.
Therefore, the guide rollers 4 and 7 and the guide pins
However, in general, when the distance Q3 is selected, the distances Q1 and Q2 can be freely selected.
Therefore, the guide rollers 4 and 7 and the guide pins
5 and 6 can be arranged at positions allowing easiest design.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A tape guide mechanism for a recording/reproducing apparatus comprising:
a tape guide drum having an axis of rotation, an outer surface, a rotary recording/reproducing head and a lead portion for regulating a drive position of a magnetic tape on said outer surface, said axis of rotation being inclined with respect to a reference plane (2);
first and second guides mounted adjacent to said drum and inclined with respect to said reference plane so as to wrap a magnetic tape around said drum through a fixed wrap angle;
a central line of said tape that extends in the longi-tudinal direction thereof and is centered in the widthwise direction thereof being inclined with respect to said reference plane and guided from a wrap start entrance point (b) to a wrap end exit point (e) through a displaced wrap central point (c1);
said displaced wrap central point (c1) being spaced apart by a displacement distance (13) from a wrap central point (c);
said wrap central point (c) lying in a plane (f) that is parallel to said reference plane and includes first and second contact points (a, e);
said first contact point (a) being at an intersection of said first inclined guide and said central line and said second contact point (e) being at an intersection of said second inclined guide and said central line;
wherein said first and second inclined guides are arranged so that said magnetic tape enters said entrance point in a direction forming a fixed elevation angle (.THETA.1) with respect to said lead portion and exits a fixed elevation angle (.THETA.2);
whereby said displacement distance (13) determines said first and second distances (11, 12).
a tape guide drum having an axis of rotation, an outer surface, a rotary recording/reproducing head and a lead portion for regulating a drive position of a magnetic tape on said outer surface, said axis of rotation being inclined with respect to a reference plane (2);
first and second guides mounted adjacent to said drum and inclined with respect to said reference plane so as to wrap a magnetic tape around said drum through a fixed wrap angle;
a central line of said tape that extends in the longi-tudinal direction thereof and is centered in the widthwise direction thereof being inclined with respect to said reference plane and guided from a wrap start entrance point (b) to a wrap end exit point (e) through a displaced wrap central point (c1);
said displaced wrap central point (c1) being spaced apart by a displacement distance (13) from a wrap central point (c);
said wrap central point (c) lying in a plane (f) that is parallel to said reference plane and includes first and second contact points (a, e);
said first contact point (a) being at an intersection of said first inclined guide and said central line and said second contact point (e) being at an intersection of said second inclined guide and said central line;
wherein said first and second inclined guides are arranged so that said magnetic tape enters said entrance point in a direction forming a fixed elevation angle (.THETA.1) with respect to said lead portion and exits a fixed elevation angle (.THETA.2);
whereby said displacement distance (13) determines said first and second distances (11, 12).
2. A mechanism according to claim 1, wherein the wrap angle of said magnetic tape around said tape guide drum is less than 180°.
3. A mechanism according to claim 1 or 2, wherein the wrap angle of said magnetic tape around said tape guide drum is about 90°.
4. A mechanism according to claim 1, wherein said first distance is selected such that said second and third distances are substantially equal to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000488981A CA1240393A (en) | 1985-08-19 | 1985-08-19 | Tape guide mechanism for a magnetic recording/reproducing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000488981A CA1240393A (en) | 1985-08-19 | 1985-08-19 | Tape guide mechanism for a magnetic recording/reproducing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1240393A true CA1240393A (en) | 1988-08-09 |
Family
ID=4131203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000488981A Expired CA1240393A (en) | 1985-08-19 | 1985-08-19 | Tape guide mechanism for a magnetic recording/reproducing apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1240393A (en) |
-
1985
- 1985-08-19 CA CA000488981A patent/CA1240393A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1078510A (en) | Magnetically recording and reproducing apparatus | |
| US5501386A (en) | Tape guide roller with flange and tapered surface for use in video tape recorder | |
| EP0083932B1 (en) | Signal recording/reproducing apparatus | |
| US4583137A (en) | Signal-recording/reproducing apparatus | |
| JPS6348094B2 (en) | ||
| US4736259A (en) | Tape guide mechanism for magnetic recording/reproducing apparatus | |
| US4155497A (en) | Tape transport mechanism for recording/reproducing apparatus, particularly for video tape recording use | |
| KR930001876B1 (en) | Tape driving device for vtr | |
| CA1240393A (en) | Tape guide mechanism for a magnetic recording/reproducing apparatus | |
| KR940006386B1 (en) | Tape tension controller for cassette recorking reproducing equipment | |
| US4875126A (en) | Stationary tape guide for a magnetic tape recorder | |
| EP0405779B1 (en) | Tape guide mechanism for helical scan recording and/or reproduction apparatus | |
| US4951163A (en) | Magnetic recording and reproducing apparatus | |
| US4964002A (en) | Magnetic recording and reproducing apparatus having a pair of skew guide blocks | |
| EP0154120B1 (en) | Tape guide arrangement for helical scan magnetic recording and playback apparatus | |
| JPS61187150A (en) | Reverse type tape running device | |
| US5568339A (en) | Recording and/or reproducing device operable with a plurality of different size cassettes | |
| JPS61175960A (en) | Tape guide device | |
| JPS6050654A (en) | Loading device of tape | |
| JPH02172050A (en) | Guide for magnetic tape | |
| JPH06176456A (en) | Magnetic recording and reproducing device | |
| JPS6120693Y2 (en) | ||
| JP3042003B2 (en) | Tape path height correction device for tape path | |
| US4953807A (en) | Stationary tape guide for a magnetic tape recorder | |
| KR200214361Y1 (en) | The tape guide apparatus for VCR |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |