JPS5897147A - Helical scanning type video tape recorder - Google Patents

Abstract

PURPOSE:To reduce dropout due to dust and wear and damage of a head and a tape remarkably, by storing a part including at least a drum out of the mechanical system of a device in a dustproof case and cleaning the inside air with a filter. CONSTITUTION:A mechanical system 6 of a VTR1 is enclosed in a dustproof device 5 to isolate the system 6 from an electric circuit 7. A dustproof device 15 including the mechanical system 6 comprising a supply reel 2, a drum 4 and a winding reel and a motor 8, 9, a dustproof case 15 incorporated with the system 6, a cover 6 and filters 18, 19 are completely interrupted from external air, and the circulating air by a fan 20 is cleaned with filters 18, 19. In high density recording and reproduction, the mixture of fine particles such as 0.5mum may give a failure, but dust particles in the enclosed space can be removed completely to prevent the adhesion of the particles on a tape 10 and a rotary head, and dropout of signals and damage to the head can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video tape recorder (hereinafter referred to as VTR) equipped with a dustproof mechanism.

Regarding helical scan VTRs, what about magnetic tape in recent years? As the characteristics of magnetic heads improve, high-density recording and reproduction are becoming more common. In this type of VT&, if dust in the air adheres to the tape in the head, accidents such as signal dropouts, wear and tear on the head, and damage to the tape and head will occur, but when performing high-density recording and playback, .

Even minute dust particles with a direct value of about 0.5 μm can cause the above-mentioned dropouts. Generally, it is said that about 107II3116I of dust particles with a size of about 0.5 μm exist in the air, and particles smaller than this are even more numerous, and particles larger than this are few. Furthermore, it is estimated that 0.5 micron dust particles enter between the rotating head and the tape using the 25.6117 formula at a rate of one per second.
．． It is thought that the probability that particles with a size of 5μ or less will enter is even higher. Therefore, as recording and reproduction become more dense, dropouts due to dust become more likely to occur. Despite improvements in the characteristics of the head and tape in conventional VTfL, the reality is that thorough dustproof measures have not been taken, and the problem of dropouts and damage to the tape and head due to dust still remains. 10 unresolved
The present invention has been made in view of the above-mentioned circumstances, and embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an open reel vertical helical scan VT device (1) to which the present invention can be applied.
A supply reel (2), a reel (3), and a drum 14) equipped with a rotary head are arranged on the top panel of 1).

Figure 2 shows the dustproof device (5) according to the present invention installed in the VTR
) is shown below.

In this embodiment, the mechanical system (6) of V T 11 is connected to the dust prevention device t (
5) Seal the electrical circuit system (separate from power).

The mechanical system (6) mainly includes the supply reel (2) and the motor (8) that drives it, the take-up reel (3) and the motor that drives it (both not shown), and the drum (4). It mainly consists of a motor (9) for driving this, and a tape (α) connected between the reel and the drum. The electric circuit (power is mainly generated from the motherboard aυ, the plurality of printed circuit boards 02 attached to this motherboard συ, and the source device α).The electric circuit system (7) and the mechanical system (6) Part means VTR+1)
It is stored in the outer casing (+41).

The dustproof device (5) is a dustproof coos Q51 made of hard plastic or the like. ★Haze, duct ση, coarse filter aL
It consists of high performance filters (I→ and fan), etc. The reel (2), motor (81+9), tape a, etc. are covered via the dust-proof case inner king 3υ.
is attached at both ends.

According to the above configuration, dustproof case α5. The space formed by tiαQ and duct) (l) is completely isolated from the outside air.
2) into the duct (Lr), and the filter (
After passing through Inyu and filtering the Zenchichi particles, they are sent into the anti-fouling case Q5 again from the entrance □□□. By circulating the air in the sealed space through the filter Qal (11), dust particles in the air can be removed and the air can be made clean. The heat dissipation fins (241 (to) are provided as appropriate, and the duct) Q7) are also provided with heat dissipation fins (2) as appropriate.
) as shown in Figure 3.
11 Case α9 wall (provided through 15 points!
This is done by connecting plugs (C) from the mechanical system (6) to both ends of several 4-pin bottles (capital), and inserting plugs (C) from the electrical circuit system (7). Dohakubin @ is 1
17i! It is provided at an appropriate location in one case a9.

As configured above, the dustproof case α9 is completely sealed, and the air in this sealed space is circulated through the filter.

The dust particles within the space between 9 and 9 are almost completely removed.Therefore, there is no possibility of dust particles adhering to the tape CL (I) and the rotating head, etc., placed inside this tray-proof case, resulting in signal dropouts and Figure 4 shows another embodiment of the present invention.
) is covered with a dustproof case (7).A tape opening and exit Sυ is provided in the case.
Attach a ring-shaped filter to the top, and select which filter
Air is taken in from the air intake row via 4.

According to the above configuration, when the drum ch 4) rotates at high speed,
The centrifugal force causes most of the airflow to flow outward from the center of the drum (4). For this reason, inside the dustproof case (to)
The air pressure in the U section becomes low. Since the air intake row is provided at a position facing the center of the drum (4) as shown in the figure,
Clean air flows in from here via the filter (2). There is a slight gap in the tape entrance/exit 61), but since the air pressure inside the dustproof case is higher than the outside air, air will not enter through this gap. 4) Since the rotation mechanism is used, there is no need to install a fan.

Therefore, this embodiment is advantageous when used as a simple dustproof device. Further, this embodiment may be used in combination with the embodiment shown in FIG. In that case, by further installing a dustproof case (to) and filter 04 inside the dustproof case α shown in Fig. 2, the
By further increasing the dust-proofing effect, it is possible to completely prevent dropouts, damage to the tape, the head, and scratches. Furthermore, the present invention can also be applied to a cassette fiVTR.

As stated above, the present invention is a helical scan type V
The mechanical system of the TR, including at least the main drum, is housed in a dustproof case, and the air inside this dustproof case is purified using a filter, which prevents dropouts and tape caused by gourd dust in the air.

Head wear, damage, etc. can be greatly reduced.

In particular, the effect can be improved even if the embodiment shown in FIG. 2 or the combination of FIG. 2 and FIG. 4 is used to perform recording and reproduction in a dusty place.

[Brief explanation of the drawing]

@1 Figure is a schematic plan view of a VTR to which the present invention can be applied;
Figure 2 is a cross-sectional side view showing an embodiment of the present invention. Figure 6 is an enlarged side view of the supporting part, and Figure 4 is a partial cross-sectional side view of the main part showing another embodiment. In addition, in the code used in Figure (3), +41・
・・・・・・・・・Padrum (5)・・・・・・
・・・・・・・・・Insect prevention device (6)・・・・・・・・・
・・・・・・Mechanical system f8×9）・・・・・・・・・・・・
・・ Motor thread ・・・・・・・・ Tape a rice ・・・ Dust-proof case Q7)
・・・・・・・・・・・・ Duct base・・・・・・・・・
・・・・・・Coarse filter thread・・・・・・・・・・・・
・・・High performance filter O2・・・・・・・・・・・・・・・
... It's a filter. Attorney: Masaru Ueya Figure 2 Figure 3 (Voluntary) Procedural Amendment March 1980 To the Commissioner of the Japan Patent Office 1 Indication of the case 1983 Patent Application No. 196075 2 Name of the invention Helical Scan Temperature Videotape recorder one or more

Claims (1)

[Claims] This helical scan type video tape recorder is characterized in that at least a portion of the mechanical system including the drum is housed in a dustproof case, and the air inside the dustproof case is purified using a filter.