Information
-
Patent Grant
-
6736526
-
Patent Number
6,736,526
-
Date Filed
Tuesday, March 19, 200222 years ago
-
Date Issued
Tuesday, May 18, 200420 years ago
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Inventors
-
Original Assignees
-
Examiners
-
CPC
-
US Classifications
Field of Search
US
- 362 294
- 362 373
- 362 260
- 362 26
- 362 261
- 362 186
- 313 493
- 313 634
- 313 31802
- 315 56
- 315 58
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International Classifications
-
Abstract
To provide a bulb-type lamp in which a globe is fixed to a case without a tilt, and a manufacturing method for the bulb-type lamp. The globe is bonded to a connector using a thermosetting resin, in a state where a neck part of the globe is inserted in a groove of the connector without contacting the bottom of the groove. The connector is then fixed to the case by means of a fitting construction. This makes it unnecessary to perform a heating process to cure an adhesive after an envelope is formed by the globe and the case. Hence the tilting of the globe caused by the thermal expansion of air in the envelope can be prevented.
Description
This application is based on an application Ser. No. 2001-089489 filed in Japan, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bulb-type lamp having a globe, such as a bulb-type fluorescent lamp and an electrodeless discharge lamp, and a manufacturing method for the bulb-type lamp.
2. Related Art
A bulb-type lamp is a kind of lamp in which a spherical globe, like the one used in an incandescent lamp, is fixed to a case. Examples of such a bulb-type lamp include bulb-type fluorescent lamps and electrodeless discharge lamps. The globe is usually made of glass in consideration of the heat generated in the lamp. Also, the globe is fixed to the case using an adhesive made of a thermosetting resin, such as a silicon resin, which has excellent heat resistance and sealing ability.
The following explains a construction of a bulb-type lamp and a method of fixing a globe to a case, taking a bulb-type fluorescent lamp as an example.
FIG. 10
is a partial broken front view of a conventional bulb-type fluorescent lamp.
This bulb-type fluorescent lamp has a globe
900
, a case
910
, an arc tube
920
, and a holder
930
. The globe
900
is made of glass and has one end opened. The case
910
is made of a resin and is engaged with the open end of the globe
900
. The arc tube
920
is made up of three U-shaped fluorescent tubes which are bridge-connected. The holder
930
is made of a resin, and is housed in an envelope formed by the globe
900
and case
910
. The holder
930
holds the arc tube
920
on one surface and an electric ballast
931
for illuminating the arc tube
920
on the other surface, and is fixed into an opening of the case
910
.
Here, a groove
940
is formed between the case
910
and the holder
930
, along the periphery of the case
910
. An edge part
900
a
of the globe
900
is inserted in this groove
940
and bonded to the case
910
through a thermosetting adhesive
941
.
Such a bulb-type fluorescent lamp can be manufactured as follows. First, the arc tube
920
and the electric ballast
931
are attached to the holder
930
. The holder
930
is then inserted into the case
910
with the electric ballast
931
being inserted first. Hence the electric ballast
931
is housed in the case
910
. Following this, the thermosetting adhesive
941
is injected into the groove
940
formed between the case
910
and the holder
930
, and the edge part
900
a
of the globe
900
is inserted into the groove
940
. The construction is then placed in a heating furnace and heated therein, to cure the thermosetting adhesive
941
. As a result, the globe
900
is fixed to the case
910
through the adhesive
941
.
With this manufacturing method, however, the globe
900
may be fixed to the case
910
in a tilted position. This causes a failure of holding the globe
900
in a correct position.
Prior to the heating process in the heating furnace, the globe
900
and the case
910
are substantially in tight contact with each other through the adhesive
941
and so the envelope formed by the globe
900
and case
910
is hermetically sealed. When the bulb-type fluorescent lamp in this state is heated in the heating furnace, the air in the envelope expands and the internal pressure increases. This being so, if the adhesive
941
is not hardened yet but is still soft, the internal pressure of the envelope may cause the globe
900
to be pushed up or tilted. If the adhesive
941
hardens in such a state, the globe
900
will end up being fixed to the case
910
in a tilted position (in more detail, the edge part
900
a
of the globe
900
is tilted upward on one side by about 4 mm). As a result, the globe
900
cannot be held in a correct position.
Bulb-type fluorescent lamps with tilted globes are all abandoned without being reused, because of their defective external appearances. Since these products are almost in finished form, they are costly and so abandoning them inevitably increases manufacturing costs.
To avoid the tilting of the globe, the following method may be employed instead of using a thermosetting resin as above. Which is to say, a stopper is provided to the edge part of the globe, whereas a stopper holding part is provided to the case. By engaging the stopper with the stopper holding part, the globe can be secured to the case. However, because the globe is made of glass, the stopper of the globe is not only difficult to form but also likely to break when engaged with the stopper holding part. For this reason, this type of bulb-type fluorescent lamp is not very practical.
The same problem can be found in electrodeless discharge lamps that have a construction similar to bulb-type fluorescent lamps, namely, a construction in which a globe is fixed to a case.
SUMMARY OF THE INVENTION
The present invention has an object of providing a bulb-type lamp that holds a globe in a correct position and so delivers an improved external appearance, and a manufacturing method for the bulb-type lamp.
The stated object can be achieved by a bulb-type lamp including: a globe having a constricted neck part at one end; a connector having a ring-shaped groove in which the neck part of the globe can be inserted, wherein the globe is bonded to the connector in a state where the neck part is inserted in the groove; a holder having a stand that supports an electric ballast; and a case having an opening, and holding the holder in a state where the holder is inserted in the case through the opening with the electric ballast being inserted first, wherein in the opening of the case, the connector to which the globe is bonded is fixed to one of the case and the holder by a fitting construction.
With this construction, the globe is held in place just by engaging the connector, to which the globe is bonded, with the case or the holder. This eliminates the need for the heating process which is conventionally performed after the envelope is formed by the globe and case. Accordingly, the tilting of the globe caused by the expansion of air in the envelope is prevented, with it being possible to hold the globe without a tilt relative to the case. As a result, the external appearance of the bulb-type lamp improves. This reduces the number of defective products, so that increases of manufacturing costs caused by abandoning defective products can be suppressed.
Here, the globe may be bonded to the connector in a state where the neck part which is inserted in the groove is kept from contact with a bottom of the groove.
With this construction, the tilting of the globe can be prevented more efficiently.
Here, the fitting construction may include a depression and a projection that fit together, the depression and the projection each being provided at a different one out of (a) the connector and (b) one of the case and the holder.
Here, the bulb-type lamp may be a bulb-type fluorescent lamp in which a fluorescent tube is supported by the stand of the holder, wherein the globe is a hollow spherical member having an open end at which the neck part is formed, a light diffusion film is formed on an internal surface of the globe using an adhesive, and the adhesive used for forming the light diffusion film is also used for bonding the globe to the connector.
With this construction, it becomes unnecessary to prepare another adhesive to bond the globe to the connector, since a single adhesive serves to form the light diffusion film and also to bond the globe to the connector. This contributes to lower manufacturing costs.
Here, the connector may be a ring having an inner wall and an outer wall which together form a U-shaped cross section, with the ring-shaped groove being present between the inner wall and the outer wall, and the globe is bonded to the connector using part of the adhesive which is gathered in the groove.
With this construction, an excess of low-viscosity adhesive which is used to form the light diffusion film can be gathered in the groove and put to use for bonding the globe to the connector.
Here, an arch-shaped leaf spring may be formed by cutting part of the inner wall of the connector, wherein the leaf spring presses the neck part which is inserted in the groove, to temporarily tack the connector to the globe until the adhesive gathered in the groove hardens.
With this construction, the globe and the connector can be positioned easily at the time of bonding, with it being possible to avoid displacements.
Here, the inner wall of the connector may have a smaller height than the outer wall of the connector.
With this construction, an excessive amount of adhesive in the groove overflows not from the outer wall but from the inner wall, so that the external appearance of the bulb-type lamp will not be ruined.
Here, a depression and a projection that fit together may be each provided at a facing portion of a different one of the connector and the holder, so that the connector and the holder move in conjunction with a rotation of the globe which is bonded to the connector.
With this construction, when the user installs the bulb-type lamp into a socket, the globe will be kept from becoming unattached from the case and turning freely on its own.
Here, the bulb-type lamp may be an electrodeless discharge lamp in which a core supporter is supported by the stand of the holder, and a coil form on which an induction coil is wound is supported by the core supporter.
The stated object can also be achieved by a manufacturing method for a bulb-type lamp, including: a holding step for holding a holder which has a stand supporting an electric ballast, by a case which has an opening, in a state where the holder is inserted in the case through the opening with the electric ballast being inserted first; a bonding step for bonding a globe which has a constricted neck part at one end, to a connector which has a ring-shaped groove in which the neck part of the groove can be inserted, in a state where the neck part is inserted in the groove; and a fixing step for fixing the connector to which the globe is bonded, to one of the case and the holder by a fitting construction, in the opening of the case.
With this method, the globe is held in place just by engaging the connector, to which the globe is bonded, with the case or the holder. This eliminates the need for the heating process which is conventionally performed after the envelope is formed by the globe and case. Accordingly, the tilting of the globe caused by the expansion of air in the envelope is prevented, with it being possible to hold the globe without a tilt relative to the case. As a result, the external appearance of the bulb-type lamp improves. This reduces the number of defective products, so that increases of manufacturing costs caused by abandoning defective products can be suppressed.
Here, in the bonding step a fixed distance may be maintained between a furthermost end of the connector and a furthermost end of the globe, wherein an adhesive is injected into the groove while keeping the neck part which is inserted in the groove from contact with a bottom of the groove, to bond the globe to the connector.
The globe is usually formed from glass and therefore tends to have variations in size. However, if the globe is bonded to the connector by injecting the adhesive into the groove while maintaining a fixed distance between the furthermost ends of the connector and globe and also keeping the neck part of the globe from contact with the bottom of the groove, the globe and the connector are held together without a tilt. As a result, a bulb-type lamp with a uniform height can be produced.
Here, the bulb-type lamp may be a bulb-type fluorescent lamp in which (a) the globe is a hollow spherical member having an open end at which the neck part is formed, and (b) a light diffusion film is formed on an internal surface of the globe using an adhesive in which a light diffusion material is dispersed, wherein when the adhesive is applied to the internal surface of the globe to form the light diffusion film, an excess of the adhesive drops and is gathered in the groove of the connector, the gathered adhesive being used to bond the globe to the connector in the bonding step.
With this construction, the adhesive used for forming the light diffusion film is also used for bonding the globe to the connector. This contributes to lower manufacturing costs.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention.
In the drawings:
FIG. 1
is a partial broken front view of a bulb-type fluorescent lamp to which the first embodiment of the invention relates;
FIG. 2
is a developed view of the bulb-type fluorescent lamp;
FIG. 3
is an expanded sectional view of main part of the bulb-type fluorescent lamp;
FIG. 4
is a perspective view of a connector;
FIGS. 5A-5D
are each a front view of the globe, in a manufacturing process of bonding the globe to the connector;
FIG. 6
is a partial broken front view of a bulb-type fluorescent lamp to which a modification to the first embodiment relates;
FIG. 7
is a partial broken front view of a bulb-type fluorescent lamp to which another modification to the first embodiment relates;
FIG. 8
is a partial broken front view of an electrodeless discharge lamp to which the second embodiment of the invention relates;
FIG. 9
is a developed view of the electrodeless discharge lamp; and
FIG. 10
is a partial broken front view of a conventional bulb-type fluorescent lamp.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
The first embodiment that applies the present invention to a bulb-type fluorescent lamp is described below, by referring to drawings.
(Construction of a Bulb-type Fluorescent Lamp)
FIG. 1
is a partial broken front view of a bulb-type fluorescent lamp of the first embodiment.
FIG. 2
is a developed view of the bulb-type fluorescent lamp.
This bulb-type fluorescent lamp has a power rating of 13 W. As shown in
FIG. 2
, the bulb-type fluorescent lamp has a globe unit
1
, a case unit
2
, and an arc tube unit
3
. The arc tube unit
3
holds a fluorescent tube
31
, and is housed in an envelope formed by the globe unit
1
and case unit
2
.
The globe unit
1
includes a globe
10
, and a connector
11
which is bonded to an edge part
10
b
at an open end of the globe
10
using an adhesive.
The globe
10
is made of pear-shaped glass having an opening
10
a
. A narrow constricted neck part
10
c
is formed near the opening
10
a
. The internal surface of the globe
10
is coated with a light diffusion film
100
(
FIG. 1
) that diffuses light emitted from the fluorescent tube
31
. The light diffusion film
100
can be formed by dispersing a light diffusion powder in a thermosetting adhesive, and applying the result to the internal surface of the globe
10
and heat-hardening it. Here, the light diffusion powder may be made of calcium carbonate, magnesium oxide, silica, titanium oxide, a phosphor, or the like, whereas the thermosetting adhesive may be made of a water-soluble acrylic emulsion, or organic nitrocellulose or ethyl cellulose. Also, to prevent damage caused by cracking, the edge part
10
b
at the opening
10
a
of the globe
10
has been heated with a burner. As a result of this, the edge part
10
b
attains a round cross section (see
FIG. 3
) and also attains some variations in height along the periphery of the globe
10
. It should be noted here that the material for the globe
10
is not limited to glass, as the globe
10
may also be formed from other materials with excellent heat resistance, such as ceramic.
The connector
11
is a ring having a U-shaped cross section, and is formed by stamping an iron plate. The connector
11
is bonded to the edge part
10
b
of the globe
10
using an adhesive. Here, it is preferable to use a thermosetting adhesive with high heat resistance, but a non-thermosetting adhesive, such as an adhesive that hardens by absorbing water in the atmosphere, is applicable too. The connector
11
is engaged with a case
20
in the case unit
2
, as a result of which the globe unit
1
is fixed to the case unit
2
.
The case unit
2
is used to fix the globe unit
1
, and also house the arc tube unit
3
. The case unit
2
has the case
20
and a base
21
.
The case
20
is formed from a resin having high heat resistance, such as polybutylene terephthalate (PBT). The case
20
is a tapered cylinder with one end opened and the other end sealed with the base
21
. Here, the base
21
is an E-type base. The internal surface of the case
20
has six depressions
200
at regular intervals along the periphery, in which stoppers
113
of the connector
11
are to be caught (though only four of the depressions
200
are shown in FIG.
2
). The internal surface of the case
20
also has a projection
201
along the periphery, below the depressions
200
. The projection
201
is used to engage with a collar
301
of a holder
30
in the arc tube unit
3
. By engaging the collar
301
with the projection
201
, the arc tube unit
3
is attached securely to the case unit
2
.
The arc tube unit
3
has the holder
30
, the fluorescent tube
31
, and an electric ballast
32
. The fluorescent tube
31
is made up of three U-shaped fluorescent tube bulbs (though only two of them are shown in
FIGS. 1 and 2
) which are bridge-connected. The electric ballast
32
has a construction in which circuits, such as a transistor and a capacitor, for illuminating the fluorescent tube
31
are provided on a substrate. The fluorescent tube
31
is provided on one surface of the holder
30
, whereas the electric ballast
32
is provided on the other surface of the holder
30
. Note that though the transistor, the capacitor, and the like are attached to the holder
30
in this example, they may be provided outside the bulb-type fluorescent lamp as a separate unit. In such a case, wiring for supplying power to the fluorescent tube
31
serves as the electric ballast
32
.
The holder
30
includes a cylindrical stand
300
and the collar
301
which is provided at the lower end of the cylindrical stand
300
along the periphery. The fluorescent tube
31
is mounted on top of the stand
300
, while the electric ballast
32
is mounted at the bottom of the stand
300
. The holder
30
is inserted into the case
20
with the electric ballast
32
entering first, as a result of which the collar
301
engages with the projection
201
in the case
20
and so the arc tube unit
3
is secured to the case unit
2
.
Also, three depressions
302
are provided on the upper end of the stand
300
at regular intervals (though one of them is hidden behind the U-shaped fluorescent tube bulbs in FIG.
2
). These depressions
302
and rotation prohibiting parts
115
(
FIG. 4
) of the connector
11
fit together. With this fitting, even if the user holds and rotates the globe
10
while screwing the bulb-type fluorescent lamp into a socket, the holder
30
and the connector
11
are kept from sliding in the direction of rotation. Therefore, the rotational power applied by the user is transmitted to the base
21
, with it being possible to reliably install the bulb-type fluorescent lamp into the socket.
The fluorescent tube
31
is made up of the three U-shaped glass bulbs which are bridge-connected, as noted above. Each glass bulb has electrodes at both ends (not illustrated). A predetermined amount of mercury and a predetermined amount of noble gas are enclosed in each glass bulb which is coated with a phosphor film on its internal surface. Hence a crooked discharge path is formed inside the fluorescent tube
31
.
(Construction of the Connector
11
)
A construction of the connector
11
which is a characteristic component in this embodiment is described below.
FIG. 3
is an expanded sectional view of a part of the bulb-type fluorescent lamp shown in
FIG. 1
which is enclosed by a dashed line.
As illustrated, the holder
30
is fixed to the case
20
by fitting the collar
301
of the holder
30
and the projection
201
of the case
20
together. The connector
11
is inserted in a groove
310
formed between the case
20
and the holder
30
along the periphery.
FIG. 4
is a perspective view of the connector
11
.
As shown in the drawing, the connector
11
is a ring with a U-shaped cross section (
FIG. 3
) that has an outer wall
110
and an inner wall
111
which are connected at the bottom. For example, the size of the connector
11
is such that the outer diameter of the outer wall
110
is 44 mm (excluding the stoppers
113
), the inner diameter of the inner wall
111
is 37 mm (excluding holding parts
114
and the rotation prohibiting parts
115
), and the height of the outer wall
110
is 10 mm. A groove
112
exists between the outer wall
110
and the inner wall
111
along the periphery. For example, the groove
112
has a width of 2 to 4.5 mm, and a depth of 8-9 mm with respect to the outer wall
110
. The connector
11
may be formed from a metal such as phosphor bronze, iron, aluminum, nickel, copper, brass, or stainless steel. As an alternative, the connector
11
may be formed from a resin such as PBT, polycarbonate (PC), polyethylene terephthalate (PET), or acrylic.
The outer wall
110
of the connector
11
is cut, on the open end side, at six portions to form the six stoppers
113
which project from the outer wall
110
. The stoppers
113
are provided with a 60° pitch along the periphery. By fitting the stoppers
113
into the depressions
200
of the case
20
as shown in
FIG. 3
, the connector
11
is fixed to the case
20
without using an adhesive. In other words, the globe unit
1
is fixed to the case unit
2
by means of fitting, so that there is no need to perform the heating to cure an adhesive after the formation of the envelope. Since the heating process which is conventionally performed after the formation of the envelope is unnecessary, the tilting of the globe caused by the expansion of air in the envelope can be prevented.
Also, the inner wall
111
of the connector
11
is cut, on the open end side, at three portions with regular intervals, to form the three holding parts
114
which project from the inner wall
111
, as shown in FIG.
4
. As shown in
FIG. 3
, these holding parts
114
are curved in an arch form toward the groove
112
. When bonding the globe
10
to the connector
11
using an adhesive in the manufacturing of the bulb-type fluorescent lamp, the holding parts
114
press the vicinity of the edge part
10
b
of the globe
10
so as to temporarily tack the connector
11
at an installation position until the adhesive hardens. In this way, displacements are suppressed.
The connector
11
has a U-shaped cross section. An adhesive
12
is injected into the groove
112
and stays there. Which is to say, even if the adhesive
12
has low viscosity, it remains in the groove
112
, so that a sufficient amount of adhesive can be secured to bond the globe
10
and the connector
11
to each other. By inserting the edge part
10
b
of the globe
10
into the groove
112
and then injecting the adhesive
12
into the groove
112
which allows the adhesive
12
to stay there, the globe
10
is bonded to the connector
11
at the edge part
10
b.
Here, it is preferable to position the edge part
10
b
of the globe
10
at a distance L
1
from the bottom of the groove
112
, as shown in FIG.
3
. The reason for this is given below. The edge part
10
b
of the globe
10
has been heated with a burner to prevent damage due to cracking. This being so, though cracks are fusion-bonded to each other, the edge part
10
b
becomes varied in height along the periphery, that is, the edge part
10
b
attains surface irregularities. In such a case, if the edge part
10
b
is in contact with the bottom of the groove
112
, such surface irregularities are likely to cause the globe
10
to tilt. However, if the edge part
10
b
is positioned at the distance L
1
from the bottom of the groove
112
, the adhesive
12
acts as a spacer to attach the globe
10
to the connector
11
without a tilt. For the same reason, even if the height of the globe
10
has some variations, the globe unit
1
can be formed with a uniform height.
Thus, the bulb-type fluorescent lamp of this embodiment is manufactured by bonding the globe
10
to the connector
11
using the adhesive
12
and then fixing the connector
11
to which the globe
10
is bonded, to the case
20
by means of fitting. Accordingly, the globe
10
can be fixed to the case
20
without having to perform the conventional heating process after the formation of the envelope. Hence the tilting of the globe
10
is prevented. Also, since the globe
10
and the connector
11
are bonded to each other with a gap in between, the globe unit
1
can be formed in a desired shape regardless of the shape of the globe
10
. When such a globe unit
1
is fixed to the case unit
2
, the globe
10
is held in a correct position without tilting against the case
20
. This enables a bulb-type fluorescent lamp having a uniform height to be produced.
(Manufacturing Method for the Bulb-type Fluorescent Lamp)
The following is an explanation of a method of manufacturing the above bulb-type fluorescent lamp.
A process of bonding the edge part
10
b
of the globe
10
to the connector
11
is explained first.
FIG. 5
shows the manufacturing process of bonding the edge part
10
b
to the connector
11
. The process proceeds in the order of
FIGS. 5A
to
5
D.
In
FIG. 5A
, the globe
10
is held by a holder
102
. The holder
102
has a support
102
a
and two arms
102
b
which are each held by the support
102
a
so as to be slidable in its facing direction. Also, each arm
102
b
is given elasticity in its facing direction. The holder
102
holds the globe
10
with the two arms
102
b
, in such a manner that the top of the globe
10
is in contact with the support
102
a
and the edge part
10
b
of the globe
10
is positioned underneath it. Here, to hold the globe
10
securely, it is more preferable for the holder
102
to have at least three arms.
In
FIG. 5B
, the connector
11
is placed on a mounting stand
103
which is used for positioning the connector
11
. The mounting stand
103
is then lifted up so that the edge part
10
b
is inserted into the groove
112
of the connector
11
. Here, the mounting stand
103
is equipped, on its mounting surface, with positioning means which engages with the connector
11
, to ensure that the connector
11
is mounted at a predetermined position. The positioning means can be realized by forming, on the mounting surface, a ring-shaped depression that engages with the connector
11
or a cylindrical projection that engages with the center hole of the connector
11
. Also, the height to which the mounting stand
103
is lifted is set such that the distance between the support
102
a
and the lifted mounting stand
103
, i.e., the distance between the upper end of the globe
10
and the lower end of the connector
11
, is a predetermined distance H. Though the distance H can be determined depending on the size of the globe
10
, it is preferable to set such a distance H that allows the gap L
1
to be present between the edge part
10
b
and the bottom of the groove
112
. Usually, each globe
10
is formed by putting glass in a shaping die. This being the case, when the size of the shaping die changes with use, the height of each globe
10
may vary to some degree. However, by setting such a fixed distance H that keeps the edge part
10
b
from contact with the bottom of the groove
112
, the distance between the upper end of the globe
10
and the lower end of the connector
11
is made uniform. As a result, the globe unit
1
can be formed with a uniform height.
In the state where the edge part
10
b
of the globe
10
is inserted in the groove
112
of the connector
11
, the connector
11
is temporarily tacked to the vicinity of the edge part
10
b
by the pressure from the holding parts
114
(FIGS.
3
and
4
). Accordingly, the mounting stand
103
can be detached from the connector
11
, as shown in FIG.
5
C. Following this, a spray nozzle
104
is inserted into the globe
10
through the hole of the connector
11
, and the adhesive
12
which contains a light diffusion material is discharged from the tip of the nozzle. As a result, the adhesive
12
is applied to the internal surface of the globe
10
, while an excess of the adhesive
12
drops into the groove
112
of the connector
11
and stays there (see the partial expanded sectional view of FIG.
5
C). In other words, with the provision of this groove
112
, the adhesive
12
is gathered even if it has only low viscosity. Thus, the adhesive
12
can be used not only to form the light diffusion film
100
but also to bond the globe
10
to the connector
11
.
Here, if the adhesive
12
overflows from the groove
112
and sticks to the outside surface of the globe
10
, the external appearance of the bulb-type fluorescent lamp is spoiled. This can be prevented by setting the smallest height of the inner wall
111
to be smaller than the smallest height of the outer wall
110
. In so doing, an excessive accumulation of the adhesive
12
in the groove
112
overflows from the inner wall
111
toward the center of the connector
11
, rather than overflowing from the outer wall
110
. As a result, the adhesive
12
is kept from sticking to the outside surface of the globe
10
. In the connector
11
shown in
FIG. 4
, for instance, the cuts of the inner wall
111
to form the holding parts
114
may be made deeper than the cuts of the outer wall
110
to form the stoppers
113
. In more detail, if the depth of cut for forming the holding parts
114
is about 3-5 mm and the depth of cut for forming the stoppers
113
is about 1-2 mm, the excess adhesive
12
overflows not from the outer wall
110
but from the cuts of the inner wall
111
.
After this, the connector
11
and the globe
10
are placed in a heating furnace while maintaining the distance H, and heated to cure the adhesive
12
. As a result, the light diffusion film
100
is formed on the internal surface of the globe
10
, and at the same time the globe unit
1
in which the edge part
10
b
of the globe
10
is bonded to the connector
11
is obtained, as shown in FIG.
5
D.
After this, the fluorescent tube
31
and the electric ballast
32
are mounted to the holder
30
, which is then inserted into the case
20
to engage the projection
201
of the case
20
with the collar
301
of the holder
30
, as shown in
FIGS. 1-3
. Hence the case
20
and the holder
30
are held together.
The connector
11
of the globe unit
1
is then inserted into the groove
310
formed between the case
20
and the holder
30
, as shown in FIG.
3
. While doing so, the rotation prohibiting parts
115
(
FIG. 4
) of the connector
11
are caught in the depressions
302
(
FIG. 2
) of the holder
30
, and the stoppers
113
(
FIG. 2
) of the connector
11
are caught in the depressions
200
of the case
20
. Here, means that keeps the connector
11
from being inserted to more than a predetermined depth is provided at the groove
310
between the case
20
and the holder
30
. In the example shown in
FIG. 3
, a slope of the projection
201
in the case
20
serves this purpose. Which is to say, by making the bottom of the connector
11
contact with this slope, the connector
11
is kept from being inserted to more than the predetermined depth.
Lastly, the base
21
is fixed to the case
20
, to complete the bulb-type fluorescent lamp.
According to the above manufacturing method, the globe
10
is bonded to the connector
11
, and then the connector
11
to which the globe
10
is bonded is fixed into the case
20
. This allows the bulb-type fluorescent lamp to be manufactured without having to perform the heating of the hermetically sealed envelope. Accordingly, the tilting of the globe
10
caused by the heating can be avoided. Also, the globe
10
is bonded to the connector
11
while keeping the globe
10
from contact with the bottom of the groove
112
of the connector
11
. In so doing, the globe unit
1
can be formed with a uniform height. Which is to say, even if the edge part
10
b
of the globe
10
has surface irregularities, the globe
10
is bonded to the connector
11
without a tilt. Therefore, the globe
10
can be held in a correct position with respect to the case
20
. This keeps the external appearance of the bulb-type fluorescent lamp from being ruined, with it being possible to avoid increases of manufacturing costs caused by abandoning defective products.
Moreover, the adhesive
12
that is used to form the light diffusion film
100
on the internal surface of the globe
10
is also used to bond the globe
10
to the connector
11
. This not only eliminates the necessity to prepare another adhesive, but also requires only one operation to cure the adhesive
12
. Hence increases of manufacturing costs can be avoided when compared with the case where another adhesive is used. Also, the manufacturing operation can be kept from becoming complex. Furthermore, an amount of adhesive necessary for bonding the globe
10
and the connector
11
to each other can be gathered reliably and easily, in the U-shaped groove
112
of the connector
11
.
(Modifications to the First Embodiment)
(1) The above embodiment describes the case where the stoppers
113
of the connector
11
are provided on the upper end of the outer wall
110
, but the invention is not limited to such. For example, the stoppers
113
may be provided at the bottom of the connector
11
.
FIG. 6
is a partial broken front view of a bulb-type fluorescent lamp to which this modification relates. This bulb-type fluorescent lamp has the same construction as that shown in
FIG. 1
, except for some differences in the shapes of the connector and case. Therefore, construction elements which are the same as those in
FIG. 1
are given the same reference numerals and their explanation is omitted.
A connector
13
is formed from a resin such as PBT, polycarbonate (PC), polyethylene terephthalate (PET), or acrylic. The connector
11
is a ring with a U-shaped cross section that has an outer wall and an inner wall which are connected at the bottom. For example, the size of the connector
13
is such that the outer diameter of the outer wall is 47 mm, the inner diameter of the inner wall is 39 mm, and the height of the outer wall is 11 mm (excluding stoppers
130
). A groove
14
is provided between the inner wall and the outer wall along the periphery. As one example, the groove
14
has a width of 4 mm, and a depth of 8 mm with respect to the outer wall. The groove
14
is filled with the adhesive
12
, which bonds the globe
10
as in the above embodiment. Also, the stoppers
130
with L-shaped cross section are projected downward from the bottom of the connector
13
along the periphery. These stoppers
130
are provided at equal intervals.
Meanwhile, depressions
220
that engage with the stoppers
130
are provided on the internal surface of a case
22
. Here, a ring-shaped groove is formed between the external surface of the holder
30
and the internal surface of the case
22
. As one example, the groove has a width W
1
of 2 mm (a maximum width W
2
in the areas where the depressions
220
are present being about 4 mm). The stoppers
130
are inserted into this groove so as to be engaged with the depressions
220
. In this way, the connector
13
and the case
22
are held together without using an adhesive. Hence the effects described in the above embodiment can be achieved. Here, the outer wall of the connector
13
is not inserted in the gap between the holder
30
and the case
22
but is exposed to the outside. Also, the case
22
has an external shape similar to the case
20
shown in
FIG. 1
, except that its total height is a few millimeters shorter than the case
20
.
Thus, the same effects as the above embodiment can still be achieved even when the stoppers of the connector are provided at different positions.
(2) The above embodiment describes the case where the connector
11
is engaged with the case
20
to hold the globe unit
1
, but the invention is not limited to such. For example, the connector
11
may be engaged with the holder
30
to hold the globe unit
1
.
FIG. 7
is a partial broken front view of a bulb-type fluorescent lamp to which this modification relates. This bulb-type fluorescent lamp has the same construction as that shown in
FIG. 1
, except for some differences in the shapes of the connector and holder. Accordingly, construction elements which are the same as those shown in
FIG. 1
are given the same reference numerals and their explanation is omitted. Note also that a case
23
shown in
FIG. 7
has an external shape similar to the case
20
in
FIG. 1
, except that its total height is a few millimeters shorter than the case
20
.
A connector
15
is made of a resin. The connector
15
is a ring with a U-shaped cross section that has an outer wall and an inner wall which are connected at the bottom. For example, the size of the connector
15
is such that the outer diameter of the outer wall is 47 mm, the inner diameter of the inner wall is 39 mm, and the height of the outer wall is 11 mm (excluding projections
151
). A groove
16
exists between the outer wall and the inner wall along the periphery. As one example, the groove
16
has a width of 4 mm, and a depth of 8 mm with respect to the outer wall. Also, the projections
151
having tapered slopes are projected downward from the bottom of the connector
15
.
Meanwhile, a holder
33
is held in the opening of the case
23
by the same fitting means as in the above embodiment, so as to leave a ring-shaped gap therebetween. Slopes
231
that engage with the tapered slopes of the projections
151
are provided around the internal surface of the case
23
. Also, projections
330
are provided around the upper end of the external surface of the holder
33
. The connector
15
is caught between the slopes
231
of the case
23
and the projections
330
of the holder
33
. As a result, the tapered slopes of the projections
151
are pushed up by the slopes
231
of the case
23
and the top
152
of the inner wall of the connector
15
is engaged with the projections
330
of the holder
33
, so that the connector
15
and the holder
33
fit together. Hence the connector
15
is held so as not to move in a direction orthogonal to a central axis X of the lamp (see FIG.
7
).
The edge part
10
b
of the globe
10
is inserted in the groove
16
of the connector
15
without contacting the bottom of the groove
16
, and is bonded to the connector
15
through the adhesive
12
as in the above embodiment.
Since the holder
33
is fixed to the case
23
through the engagement of the collar
301
as in the above embodiment, the globe
10
and the case
23
are held together without having to use an adhesive. This eliminates the necessity to perform the heating after the formation of the envelope.
Thus, the effects of the above embodiment can still be achieved even if the connector
15
and the holder
33
fit together in this way. Note here that the outer wall of the connector
15
is exposed to the outside in this modification.
(3) Though the connector is engaged with the case or the holder in the above embodiment and modifications, the same effects can still be obtained even when the connector is engaged with a component which integrates the case and the holder.
(4) The above embodiment describes the case where the bulb-type fluorescent lamp has a power rating of 13 W. However, the power rating should not be limited to such, so that the invention can be applied, for example, to a bulb-type fluorescent lamp with a power rating of 22 W.
Second Embodiment
The first embodiment describes the case when the invention is used for a bulb-type fluorescent lamp. On the other hand, the second embodiment describes the case when the invention is used for an electrodeless discharge lamp.
An application of the present invention to an electrodeless discharge lamp is explained below, with reference to drawings.
(Construction of an Electrodeless Discharge Lamp)
FIG. 8
is a partial broken front view of an electrodeless discharge lamp to which the second embodiment of the invention relates.
FIG. 9
is a developed perspective view of the electrodeless discharge lamp.
As shown in these drawings, the electrodeless discharge lamp has a globe
4
, a coil unit
5
, a connector
6
, a holder
7
, and a case unit
8
. The holder
7
is inserted in the case unit
8
, and the connector
6
to which the globe
4
and the coil unit
5
are attached is fixed onto the holder
7
.
The globe
4
is a hollow spherical member made of glass, and has a constricted neck part
40
at its lower end. A cylindrical depression
41
is formed from the neck part
40
toward the center of the globe
4
, and a canalicular part
42
extends along a direction of a central axis of the depression
41
. The globe
4
is coated with a phosphor film on its internal surface, and filled with noble gas and a metal vapor of mercury or the like.
The coil unit
5
has a cylindrical coil form
50
and an induction coil
51
which is wound on the coil form
50
. A core
52
(
FIG. 8
) made up of a cylindrical ferrite core, iron core, or the like is inserted in the coil form
50
. The coil unit
5
is provided in the depression
41
of the globe
4
. When power is applied to the induction coil
51
, an electric field occurs in the globe
4
, which causes the enclosed metal vapor to collide with electrons. As a result, ultraviolet light is emitted from the metal vapor. This ultraviolet light excites the phosphor film on the internal surface of the globe
4
to emit light. To attach the coil unit
5
to the connector
6
, one end of the coil form
50
is fitted into an opening
60
of the connector
6
.
The connector
6
is a cylindrical member having the opening
60
at the center, as shown in FIG.
9
. Also, a groove
61
with a U-shaped cross section is provided along the periphery of the connector
6
. Four depressions
62
are provided at regular intervals on the outer wall of the connector
6
. By engaging the depressions
62
with projections
800
of a case
80
in the case unit
8
, the connector
6
is fixed to the case
80
.
The holder
7
has a stand
70
, a core supporter
71
, and an electric ballast
72
. The cylindrical core supporter
71
for supporting the core
52
is projected from the center of one surface of the stand
70
, whereas the electric ballast
72
is provided on the other surface of the stand
70
. The electric ballast
72
is equipped with a high-frequency oscillation circuit for converting power applied from the outside into a high-frequency signal which is to be supplied to the induction coil
51
, a rectifier, and similar (both the oscillation circuit and the rectifier are not illustrated). Also, a collar
73
is provided on the side wall of the stand
70
along the periphery. By engaging the collar
73
with a projection
801
of the case
80
, the holder
7
is fixed to the case
80
and the electric ballast
72
is housed in the case
80
. Though the high-frequency oscillation circuit and the like are mounted on the holder
7
in this example, they may be provided outside the electrodeless discharge lamp as a separate unit. In such a case, wiring for supplying the high-frequency signal to the induction coil
51
serves as the electric ballast
72
.
The case unit
8
has the case
80
and a base
81
. The case
80
is a tapered cylinder. The base
81
is an E-type base which seals one end of the case
80
. The other end of the case
80
is opened. The internal surface of the case
80
has the projections
800
and the projection
801
. When the holder
7
is inserted through the opening of the case
80
with the electric ballast
72
facing the case
80
, the projections
800
and the projection
801
engage with the depressions
62
of the connector
6
and the collar
73
of the stand
70
, respectively.
(Construction of the Connector
6
)
A construction of the connector
6
which is a characteristic component in this embodiment is explained below.
As shown in
FIG. 8
, the connector
6
is bonded to the neck part
40
of the globe
4
through an adhesive
400
, in the groove
61
. Here, the neck part
40
is positioned at a distance L
2
from the bottom of the groove
61
. In this way, even when the height of the globe
4
varies or the neck part
40
has surface irregularities, the globe
4
can be attached to the case
80
without a tilt, as in the first embodiment. Hence the electrodeless discharge lamp can be manufactured with a uniform height.
Here, the globe
4
and the connector
6
may be bonded to each other using a method similar to that shown in FIG.
5
. The only difference lies in that an adhesive needs to be poured into the groove
61
of the connector
6
in the step of FIG.
5
C.
The globe
4
which is bonded to the connector
6
in such a way can be fixed to the case unit
8
just by engaging the connector
6
with the case
80
. This makes it unnecessary for the globe
4
to be directly bonded to the case unit
8
using an adhesive. Accordingly, the heating to cure an adhesive after the formation of the envelope becomes unnecessary. Thus, the same effects as the first embodiment can be achieved when the present invention is applied to an electrodeless discharge lamp.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art.
Therefore, unless such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
Claims
- 1. A bulb-type lamp comprising:a globe having a constricted neck part at one end; a connector having a ring-shaped groove in which the neck part of the globe can be inserted, wherein the globe is bonded to the connector in a state where the neck part is inserted in the groove; a holder having a stand that supports an electric ballast; and a case having an opening, and holding the holder in a state where the holder is inserted in the case through the opening with the electric ballast being inserted first, wherein in the opening of the case, the connector to which the globe is bonded is fixed to one of the case and the holder by a fitting construction.
- 2. The bulb-type lamp of claim 1,wherein the globe is bonded to the connector in a state where the neck part which is inserted in the groove is kept from contact with a bottom of the groove.
- 3. The bulb-type lamp of claim 1,wherein the fitting construction includes a depression and a projection that fit together, the depression and the projection each being provided at a different one out of (a) the connector and (b) one of the case and the holder.
- 4. The bulb-type lamp of claim 1 being a bulb-type fluorescent lamp in which a fluorescent tube is supported by the stand of the holder,wherein the globe is a hollow spherical member having an open end at which the neck part is formed, a light diffusion film is formed on an internal surface of the globe using an adhesive, and the adhesive used for forming the light diffusion film is also used for bonding the globe to the connector.
- 5. The bulb-type lamp of claim 4,wherein the connector is a ring having an inner wall and an outer wall which together form a U-shaped cross section, with the ring-shaped groove being present between the inner wall and the outer wall, and the globe is bonded to the connector using part of the adhesive which is gathered in the groove.
- 6. The bulb-type lamp of claim 5,wherein an arch-shaped leaf spring is formed by cutting part of the inner wall of the connector, and the leaf spring presses the neck part which is inserted in the groove, to temporarily tack the connector to the globe until the adhesive gathered in the groove hardens.
- 7. The bulb-type lamp of claim 5,wherein the inner wall of the connector has a smaller height than the outer wall of the connector.
- 8. The bulb-type lamp of claim 4,wherein a depression and a projection that fit together are each provided at a facing portion of a different one of the connector and the holder, so that the connector and the holder move in conjunction with a rotation of the globe which is bonded to the connector.
- 9. The bulb-type lamp of claim 1 being an electrodeless discharge lamp in which a core supporter is supported by the stand of the holder, and a coil form on which an induction coil is wound is supported by the core supporter.
- 10. In a light emitting bulb, the improvement comprising:a globe having a light emitting diffusing coated surface; a support member for mounting the globe; and an adhesive for bonding the support member to the globe, the adhesive having a light diffusing characteristic wherein the adhesive coats the light emitting surface of the globe for diffusing the light and also provides the bonding of the globe to the support member.
- 11. The light emitting bulb of claim 10 wherein the support member has a ring configuration with a u-shaped cross section, an inner wall of the support member has a height lower than an outer wall to enable any overflowing adhesive to flow over the inner wall.
- 12. The light emitting bulb of claim 11 wherein the support member has a plurality of spring projections to hold the globe.
- 13. A method of assembling a light emitting bulb with a light diffusing globe comprising the steps of:positioning the globe adjacent a support member; coating an interior surface of the globe with an adhesive having a light diffusing characteristic; and continuing the coating step after the interior surface of the globe is coated to provide sufficient adhesive between the globe and the adjacent support member to bond the globe to the support member with the adhesive.
- 14. The method of claim 14 further including drying the adhesive without heating.
- 15. A bulb-type lamp assembly formed by modular components, comprising:a globe having a transparent body for transmitting light with an opening having a peripheral connector affixed to and extending about the opening, the opening of a size to receive a light emitting member, the globe connector having an exterior surface with a first fastening unit comprising one of a projecting fastener member and a fastener depression; a holder supporting a light emitting member; and a case member having an opening for supporting the holder, the case member having an interior surface with a second fastening unit comprising one of a projecting fastener member and a fastener depression of a configuration to cooperatively secure the first fastening unit of the globe connector to the case member by relatively forcing the globe connector exterior surface into the case member interior surface, with the holder captured between the globe connector and the case member, to enable an automatic fastening by engagement of the respective projecting fastener member with the fastener depression whereby the bulb-type lamp is provided with a fitting construction without additional fasteners.
- 16. The bulb-type lamp assembly of claim 15 wherein the globe connector has an interior surface with radially inward projections and the holder has complementarily depressions to receive the projections and prevent relative rotation.
- 17. The bulb-type lamp assembly of claim 15 wherein the transparent body of the globe is coated with a light diffusing adhesive mixture that also bonds the peripheral connector to the globe.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-089489 |
Mar 2001 |
JP |
|
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
704101 |
Sep 1999 |
EP |
6196000 |
Jul 1994 |
JP |
8511650 |
Dec 1996 |
JP |