JPH04134709A - Magnetic head for camera - Google Patents

Abstract

PURPOSE:To prevent the degradation of a magnetic head performance and the damage of a magnetic storage part by forming a coating layer on the surface of two cores, and deciding the width of a magnetic gap formed at each core with the thickness of the coating layer. CONSTITUTION:A magnetic gap 22 formed by two cores 21 obtains a gap length (g) by the thickness of coating layers 21a exerted to each of the two cores 21, and the need for a gap member is eliminated. Also, a coating layer 21a is provided on the front surface 20a of a head opposed to the magnetic storage part 3a of a photographic film 3 to eliminate the direct exposure of the core 21. Thus, the degradation of the performance of the magnetic function attending to the corrosion of the core which forms the magnetic gap 22, and the damage of the magnetic storage part provided on the photographic film can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to an improvement in a magnetic head for a camera that writes new information by demagnetizing information previously written in a magnetic storage section provided in a photographic film. It is something.

(Background of the Invention) U.S. Pat. No. 4,878,075 discloses a transparent magnetic recording layer (
A camera has been disclosed in which information is written in advance by magnetic recording on a photographic film coated with a magnetic storage section (hereinafter referred to as a magnetic storage section), and has a magnetic head capable of rewriting this magnetic recording.

Fig. 5 shows the outline thereof, 101 is a film cartridge, 102 is a photographic film, and this 13th
The figure is seen from the pace side of the photographic film 102, and this surface is coated with a magnetic memory section 107, and this magnetic memory section 107 is preliminarily coated with an I/O layer by magnetic recording.
Information such as SO (hereinafter referred to as original information) is written. 103 is a perforation. 104-10
5 is a shooting frame on the photographic film 102, and 1
04 is a photographed frame, and 105 and 106 are unphotographed frames.

Reference numeral 111 denotes a magnetic head that adds information such as date 0 time, shutter speed, etc. (hereinafter referred to as additional information) in synchronization with the photographic film 102 being fed in the direction of arrow A, and 111 is a magnetic head that adds information such as date 0 time and shutter speed (hereinafter referred to as additional information) to the photographed frame. Although additional information has already been written in the magnetic storage section 107a of frame 104 by the magnetic head 108, the original information remains in the magnetic storage sections 107b and 107c of unphotographed frames 105 and 106.

Here, the magnetic storage sections 107a to 107c are provided on one end surface side of the photographic film 102. this is,
The layout is designed to prevent film scratches from occurring within the photographic frame due to the sliding movement of the magnetic head 111 and the photographic film 102.

On the other hand, in Japanese Patent Application No. 2-11588, the applicant of the present application
We have proposed a method for additionally writing predetermined information by demagnetizing the original information on photographic film using a magnetic head provided in the camera at a frequency sufficiently lower than the writing frequency.

This is characterized by the fact that the recording method is demagnetization using the low frequency of the original signal, so the magnetic storage part of the photographic film and the magnetic head of the camera do not necessarily need to be in contact with each other. In other words, in a normal recording method, during recording, a photographic film, which is a magnetic medium, is held between a magnetic head and a pad member placed on opposite sides of the photographic film under a predetermined pressure, and the magnetic head and photographic film are held together under a predetermined pressure. Maintaining contact is essential. This configuration has the disadvantages of increasing the film feeding load, impairing the flatness of the photographic film during shooting, and deforming the photographic film if left for a long time. In this case, a mechanism for retracting either the magnetic head or the pad member from the film sandwiching state is required, which results in an increase in cost.

The recording method using demagnetization proposed above eliminates this drawback and makes it possible to simplify the configuration of the camera.

FIG. 6 is a cross-sectional view of a camera showing a state in which the degaussing magnetic head 111 described above is incorporated into the camera.

In FIG. 6, 112 is a camera body, which is a known 2
It has an outer book rail 112a, two inner rails 112b, an aperture opening 112C, and a recess 112d. A pressure plate 113 is pressed against the outer rail 112a.6 The photographic film 102 is attached to the outer rail 112a.

The light beam is exposed while traveling or stopping in the space (tunnel) formed by the inner rail 112b and the pressure plate 113. Also,
As shown in the figure, the end surface 102a of the photographic film 102 has a curling characteristic toward the camera body 112 side. Due to the curling characteristic of the recess 1'12d formed between the outer rail 112a and the inner rail 112b, the end surface 102a strongly hits the main body 112, causing an increase in the load during feeding and preventing the photographic film from being placed on the pressure plate 113. This prevents the situation where the film 102 becomes misaligned and the flatness of the film deteriorates during photographing.

The magnetic head 111 is fixed to a pressure plate 113, and is attached to the magnetic storage section 10 of the photographic film 102 with a slight gap S.
7 facing the base surface. As mentioned above, since the magnetic storage section 107 is located on the side of the end surface 102a of the photographic film 102 outside the photographic frame, the mounting position of the magnetic head 111 is, of course, corresponding to this.

Further, a surface 111a of the magnetic head 111 facing the photographic film 102 is arranged to be aligned with a surface (pressure plate surface) 113a of the pressure plate 113 that contacts the outer rail 112a, or to be slightly separated from the photographic film 102. This structure prevents the magnetic heald 111 from hitting the outer rail surface 112a and from damaging the flatness of the photographic film 102.

FIG. 7 shows the main part of the BB cross section in FIG. 6,
The configuration of the magnetic helad 111 is shown.

The magnetic head 111 has a core 1 made of a material with high magnetic permeability.
11b, 111c, a bobbin 1lld for winding the coil 1lle, and a resin kokutai 111h holding these.
It consists of Moreover, 111f and 111g are bobbin terminals for pulling out both ends of the wound coil 111e outside the resin national body 111h.

The front surface 111a of the magnetic head 111 is eight-sided in order to reduce the sliding part with the film 102.
llb, 1llc and the resin national body 111h form this surface. Therefore, the cores 111b and 111c are exposed from the resin national body 111h on the surface facing the photographic film 102. Also, 1lli is core 1llb, 1ll
This is a magnetic gap for performing magnetic recording formed by c, and in order to obtain the gap length g, the gap member 111j
is used.

As a manufacturing method of this magnetic helad 111, first, a bobbin 111d to which bobbin terminals 111f and 111g are fixed is manufactured.
A coil 111e is wound around the coil 111e, and two cores 111
First, manufacture a unit that integrates b and 111c.

At this time, a gap member 111j is inserted between the cores 111b and 1llc.

Next, with the unit temporarily fixed, resin sealing is performed to form the resin national body 111h. Thereafter, the front surface 111a of the magnetic head 111 is processed into a smooth rounded surface by means such as grinding.

S shown in FIGS. 6 and 7 above is the magnetic head 111.
front side 111a and magnetic storage section 10 of photographic film 102
7 spacing.

In this recording method, after allowing the spacing S,
The magnetic storage section 107 is demagnetized by the magnetic head 111 for demagnetization.
It is necessary to demagnetize the original information above. Therefore, in order to demagnetize the original information previously recorded on the photographic film 102, the voltage (flowing current) applied to the magnetic head 111 needs to have a high value. However, when the current increases, the amount of magnetic flux generated by the core changes depending on the saturation magnetic flux capability of the core itself.

Generally, the saturation magnetic flux density of the core material used in the magnetic head 111 is: 78% permalloy 7000 to 8000 gauss
・Ferrite 3000~5000gauss
・Sendust 8000~10000100O
It is as low as 0, and it is very difficult to make it higher than this with 78% permalloy and ferrite.

With such a low value, if there is a gap between the photographic film 102 and the magnetic head 111 when it runs, sufficient demagnetization characteristics cannot be obtained, and the magnetic head 111 for degaussing no longer functions.

Therefore, in this way, the photographic film 102 and the magnetic head 1 are
11, a core material with high saturation magnetic flux density is required.

However, by using a core material with a high saturation magnetic flux density, such as 5i-Fe (silicon steel plate), it becomes possible to demagnetize the original information.

Materials with high saturation magnetic flux density include: Silicon steel plate material of 13,000 gauss or more Sendust 12
000gauss or more/amorphous 11000g
auss or higher.

By using a material with a high saturation magnetic flux density as described above, even if a gap occurs between the photographic film and the core, the original information recorded on the photographic film can be easily demagnetized.

As described above, it is necessary to use a material with high saturation magnetic flux density for the core material of the magnetic head used in the demagnetization recording method.

However, materials with high saturation magnetic flux density tend to corrode, as silicon steel sheets are particularly noticeable, and as in the past, the core material was exposed on the surface of the magnetic head (the sliding surface with the photographic film). If the configuration is assembled into a camera as it is, the core material will corrode due to changes over time in the environment in which the camera is used, making it impossible to obtain the desired performance of the magnetic head, and the corroded portion may damage the magnetic storage section of the photographic film. When you come into contact with
This results in the inconvenience of damaging the magnetic storage section.

On the other hand, the gap members necessary to form the magnetic gap are made of titanium foil, etc., and are not only expensive but also thin, usually from several micrometers to several tens of micrometers, making it difficult to manage parts and handle assembly. This is extremely troublesome.

Therefore, it is desirable to eliminate the gap member.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, and to solve the problem of deterioration of magnetic head performance due to corrosion of the core forming the magnetic gap.
Another object of the present invention is to provide a magnetic head for a camera that can prevent damage to a magnetic storage section provided in a photographic film, reduce parts costs, and improve ease of handling during assembly of parts management.

(Characteristics of the Invention) In order to achieve the above object, the present invention forms a coating layer on the surfaces of two cores, and the width of the magnetic gap formed by each core is determined by the thickness of the coating layer. The width of the magnetic gap is determined by the thickness of the coating layer, and a special member is used to determine the width of the magnetic gap so that the magnetic recording portion of the core is not exposed. It is characterized by having no.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 4 is a diagram showing the configuration of the camera according to the present invention, 1
1 is a camera body having a cartridge chamber 1a for storing a film cartridge 2, a spool chamber 1b for storing a film winding Lisbourg 7, an opening 1e for photographing, and two outer rail ICs and an inner rail 1d. Reference numeral 3 denotes a photographic film, which travels in a tunnel formed by the two outer rail ICs, 12 inner rails ld, and a pressure plate 10, which will be described later. Reference numeral 4 represents a bar foration provided on the photographic film 3, and reference numeral 5 represents a photographing frame. 8.9 is a leaf spring, and a rotating roller 8a is attached to the tip of the leaf spring.

9a is provided, and has a function of automatically winding the leading end of the photographic film 3 around the film take-up spool 7 during autoloading using a known configuration. 10 is a pressure plate, and the first
As in Figure 4, it is in contact with the outer rail IC.

Reference numeral 13 denotes a magnetic head that performs degaussing magnetic recording.
is fixed. Reference numeral 13a denotes the front surface of the head, which faces the magnetic storage section 3a provided on the photographic film 3. 14 and 15 are bobbin terminals.

18 is a fork that engages with the spline 2a of the film cartridge 2, and when it is rotated in the direction of arrow B by a drive mechanism (not shown), the photographic film 3 is sent out from the cartridge 2 and rotated in the opposite direction. In this case, the photographic film 3 is rolled into the cartridge 2 (
(Disclosed in Japanese Patent Application Laid-Open No. 2-67534, etc.).

1 to 3 show an embodiment of the magnetic head 13 shown in FIG. 4, FIG. 1(A) is a front view of the completed magnetic head 13, and FIG. 1(B) is a side view thereof. 2 shows the core alone, and FIG. 3 shows the core with a coating applied around the core (surface).

In FIG. 2, 21 indicates a single core made of a material with high saturation magnetic flux density such as a silicon steel plate, and the hindlimb core 2
1 is coated with a coating (coating layer 21a) having a thickness of t, as shown in FIG. 3, and becomes a coated core.

In FIG. 1, two cores 21 are coated, and 22 is a magnetic gap formed by the two cores 21 and required for a normal magnetic head.

The magnetic gap 22 has a coating layer 2 on the core 21.
1a, a gap member is required to fill the gap in order to accurately obtain the gap length g, but in this embodiment, each of the two cores 21 is Since the gap length g can be obtained by the thickness t of the coating layer 21a, it is possible to eliminate the need for a gap member.

Reference numeral 25 denotes a resin used to connect and hold a bobbin 26, which will be described later, and which also serves as a housing together with the two cores 21. 26 is the aforementioned bobbin for winding the coil 23, and has a leg portion 26b extending to the right in FIG. It is formed. Further, 24a is two bobbin terminals (terminal conductors) (one (24b) is not shown) for drawing out both ends of the wound coil 23, and corresponds to bobbin terminals 14 and 15 in FIG. It is fixed to the bobbin 26.

Here, the coating material shown in FIG. 3 is necessarily required to be a non-magnetic material, but it may be either a conductive material or a non-conductive material, and there is a wide range of materials that can be used.

Therefore, the coating method is painting or electrolytic plating.

Various methods such as electroless plating are possible.

Further, the head front surface 20a facing the magnetic storage section 3a of the photographic film 3 is provided with the coating layer 21a as described above, so that the core 21 is not directly exposed.
Inconveniences such as deterioration in the performance of the magnetic head 13 and damage to the magnetic storage section 3a of the photographic film 3 due to corrosion of the core 21 can be eliminated.

Next, the operation of the camera shown in FIG. 4 having the degaussing magnetic head 13 having the configuration shown in FIGS. 1 to 3 will be described.

Cartridge 2 is placed in the film cartridge chamber 1a of the camera.
When the film is loaded and the fork 18 begins to rotate in the direction of arrow B in FIG.
will be sent out. When the leading end of the photographic film 3 reaches the film take-up spool 7 rotating in the same direction as the fork 18, rotating rollers 8a and 9 provided on the film take-up spool 7 and the leaf spring 8.
The photographic film 3 is wound onto the film take-up spool 7 by the cooperation of the members a. Thereafter, the photographic film 3 is pulled and fed by the film take-up spool 7. At this time, the rotation of the fork 18 is brought into a non-driven state by a known one-way clutch mechanism or the like.

This behavior is well known (Japanese Patent Application Laid-Open No. 2-675
No. 36, Japanese Unexamined Patent Publication No. 60-45231, etc.), detailed explanation thereof will be omitted.

Even after the above-mentioned autoloading operation is completed, the film feeding continues, and the perforation 4 of the photographic film 3 is detected by the quantum illustrated photointerrupter, etc., and the first frame is placed at the position corresponding to the photographing aperture 1e. When it is detected that the photographic film 3 has arrived, the feeding of the photographic film 3 is stopped. Then, by performing a known release operation, 1
The frame is exposed to light, and upon completion of the exposure operation, winding for one frame is started. This winding for one photographic frame is also performed by the detection of the perforation 4.

During the winding of the photography frame, the winding 23 of the magnetic head 13 shown in FIG. 1 is connected to the bobbin terminal 24a.

Intermittent direct current is applied from a head drive circuit (not shown) via 24b. As a result, a magnetic field is intermittently generated in the magnetic gap 22 formed by the two cores 21. Therefore, the original information already recorded in the magnetic storage section 3a of the photographic film 3 that ran in front of the magnetic gap 22 while the winding 23 was energized is erased (demagnetized) by direct current.
The state will be as follows. Newly encoded information is written as additional information based on the number of times per frame of this DC erased portion or the length of a single DC erased portion.

According to this embodiment, since a coating layer is formed on the surface facing the photographic film of the core made of a material with high saturation magnetic flux density that forms the magnetic gap of the magnetic head, corrosion of the core may occur. Inconveniences such as deterioration of magnetic head performance and damage to the magnetic storage part of photographic film can be eliminated, and furthermore, since the coating layer functions as a gap member, parts cost and parts management can be reduced.

It has become possible to improve handling during assembly, and it has also become possible to reduce the cost of the magnetic head at the same time.

(Effects of the Invention) As explained above, according to the present invention, a coating layer is formed on the surfaces of two cores, and the width of the magnetic gap formed by each core is determined by the thickness of the coating layer. The width of the magnetic gap is determined by the thickness of the coating layer, and a special member is used to determine the width of the magnetic gap so that the magnetic recording portion of the core is not exposed. By eliminating this, it is possible to prevent a decline in the performance of the magnetic head due to corrosion of the core that forms the magnetic gap, and to prevent damage to the magnetic storage section of the photographic film, as well as to reduce parts costs and parts management. It becomes possible to improve the handling during assembly.

[Brief explanation of the drawing]

FIG. 1(A) is a front view showing an embodiment of the present invention, FIG. 1(B) is a side view thereof, FIG. 2 is a front view showing the core, and FIG. 3 is a core-coil coupling. 4 is a perspective view showing the main structure of a camera incorporating the magnetic head shown in FIG. 1; FIG. 5 is a diagram showing the relationship between a conventional degaussing magnetic head and photographic film; Figure 6 is the 5th
FIG. 7 is a longitudinal cross-sectional view showing the configuration of a main part of a camera in which the illustrated magnetic head is incorporated, and FIG. 7 is a cross-sectional view taken along the line BB in FIG.

Claims (1)

[Claims] (1) By demagnetizing the information previously written in the magnetic storage part of the photographic film, which is made of a material with high saturation magnetic flux density and has two cores that make up the magnetic gap of the magnetic head, new In a magnetic head for a camera that writes information, a coating layer is formed on the surfaces of the two cores, and the width of the magnetic gap formed by each core is determined by the thickness of the coating layer. A magnetic head for a camera, which is characterized by: