Title: LED illuminator
Abstract: Each of a plurality of LED lamp modules includes a base, an LED drive circuitry mounted on the base, and a cover coupled with the base to cover the LED drive circuitry. The LED lamp modules are stacked one on another. A single flat cable is extending through the LED lamp modules so as to have at least one first portion disposed outside the LED lamp modules and a plurality of second portions disposed inside the LED lamp modules to be electrically connected to the LED drive circuitry in each of the LED lamp modules. The first portion of the flat cable is sandwiched between the base of an upper one of the LED lamp modules and the cover of a lower one of the LED lamp modules.
Patent Number: 6,994,455 Issued on 02/07/2006 to Okabe, et al.
| Inventors:
|
Okabe; Toshiaki (Shizuoka, JP);
Matsushita; Haruyuki (Shizuoka, JP)
|
| Assignee:
|
Yazaki Corporation (Tokyo, JP)
|
| Appl. No.:
|
870184 |
| Filed:
|
June 18, 2004 |
Foreign Application Priority Data
| Jun 20, 2003[JP] | 2003-175903 |
| Current U.S. Class: |
362/362; 362/800; 362/227; 362/545; 362/249 |
| Current Intern'l Class: |
F21V 29/00 (20060101) |
| Field of Search: |
362/226,227,555,545,546,249,240,362,800
361/679,728,729,730,735,736
|
References Cited [Referenced By]
U.S. Patent Documents
| 6038130 | Mar., 2000 | Boeck et al.
| |
| 6483254 | Nov., 2002 | Vo et al.
| |
| 6680200 | Jan., 2004 | Everett.
| |
| 6905228 | Jun., 2005 | Takeyasu et al.
| |
| 2004/0240229 | Dec., 2004 | Blumel et al.
| |
| 2005/0068777 | Mar., 2005 | Popovic.
| |
| 2005/0105291 | May., 2005 | Wu.
| |
| Foreign Patent Documents |
| 9-272377 | Oct., 1977 | JP.
| |
Primary Examiner: O'Shea; Sandra
Assistant Examiner: Ton; Anabel
Attorney, Agent or Firm: Sughrue Mion, PLLC
Claims
What is claimed is:
1. An LED illuminator, comprising:
a plurality of LED lamp modules, each of which comprises:
a base;
an LED drive circuitry, mounted on the base; and
a cover, coupled with the base to cover the LED drive circuitry, the LED lamp
modules being stacked one on another; and
a flat cable, extending through the LED lamp modules so as to have at least one
first portion disposed outside the LED lamp modules and a plurality of second portions
disposed inside the LED lamp modules to be electrically connected to the LED drive
circuitry in each of the LED lamp modules,
wherein the first portion of the flat cable is sandwiched between the base of
an upper one of the LED lamp modules and the cover of a lower one of the LED lamp modules.
2. The LED illuminator as set forth in claim 1, wherein an outer face of the
base is formed with a groove for receiving the first portion of the flat cable.
3. The LED illuminator as set forth in claim 1, wherein the cover comprises a
retainer which retains each of the second portions of the flat cable on an inner
face of the base.
4. The LED illuminator as set forth in claim 1, wherein each of the LED lamp
modules comprises a guide member disposed on an inner face of the base to restrict
a lateral movement of each of the second portions of the flat cable.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a small-sized illuminator provided with an LED
(light-emitting diode) which is used as a room light or a map light of a vehicle
to illuminate the cabin and the interior of a container for small items such as
a console box, a glove compartment, an accessory pocket, or an ash tray. It may
also illuminate a cup holder or the area of passengers' feet.
FIG. 6 shows a first example of a related-art illuminator which is disclosed
in Japanese Patent Publication No. 9-272377 (cf., pages 2-4, FIG. 1).
In this example, an illuminator
60 is capable of illuminating the interior
of containers for small items such as a console box
66 with adequate luminance
at low power consumption. The illuminator comprises a main body
61, a circuit
board
63 attached to the main body
61, and a lens
65 which
covers the circuit board
63.
The main body
61 is formed in a box-shaped general configuration using
a synthetic resin material. A mount
62 for mounting the illuminator
60
to a surface of a wall of the console box
66 is provided in a lower part
of the main body
61. Each of the circuit board
63 and the lens
65
is securely held on the main body
61 using an engagement member.
A plurality of LED chips
64 are mounted on the circuit board
63.
The LED chips
64 are arrayed and connected to an alternator and a battery
through branch lines
66 so that the emitted light linearly. The circuit
board
63 is also provided with electronic components such as a rectifier
diode for preventing noises and a current limiting resistor which are not shown.
The lens
65 is formed in a box-shaped configuration from a highly transparent
synthetic resin material. Therefore, light emitted from the LED chips
64
is converged as it passes through the lens
65 to illuminate the interior
of the console box
66 with high luminance.
With such a configuration, since a large number of LED chips
64 are mounted,
an illuminator can be provided which can illuminate the interior of a container
for small items with sufficient luminance and which consumes small power.
In this example, since ends of the two branch lines
66 are connected to
the circuit board
53, a new branch line
66 must be formed on the
trunk line to provide an additional illuminator. This is troublesome and costly,
and a problem arises in that an additional illuminator cannot be easily provided.
Further, since the plurality of LED chips
64 is mounted on the circuit
board
63, a problem arises in that the main body
61 is therefore
large-sized and cannot be mounted to a container for small items which has only
a small space therein. For example, the lamp may not be mounted to an ash tray
or cup holder. When the intervals between the plurality of LED chips
64
are decreased to reduce the size of the illuminator
60, a problem arises
in that the temperature in the illuminator
60 increases because of poor
heat radiation to reduce light-emitting efficiency. In particular, a red LED chip
may undergo an abrupt reduction of light-emitting efficiency at a high temperature.
When the illuminator
60 is used in a container for small items such as
an ash tray or cup holder, it will sufficiently work with a small number of LED
chips
64 because high luminance is not required. When the illuminator
60
is used in a console box or a glove compartment or used as a map light, it must
have a large number of LED chips
64 because high luminance is required.
While the number of the LED chips
64 depends on the size of the container
for small items or the place to be illuminated, the illuminator
60 cannot
accommodate an increase or decrease in the number of the LED chips
64 with
flexibility. It is therefore required to redesign the main body
61, the
circuit board
63, and the lens
65 to satisfy such a requirement,
which results in the problem of an increase in total cost including tooling costs.
FIG. 7 shows a second example of an related-art illuminator. In this example,
illuminators
70 which are mounted in containers for small items such as
a console box and glove compartment in a way similar to that in the first example.
The illuminators
70 are connected to a wire harness
75 provided in
a vehicle through joint connectors
71, branch lines
72, and module-side
connectors
73 in a manner so-called bus-type connection.
When an additional illuminator
70 is to be provided, a new joint connector
71, branch line
72, and module-side connector
73 are prepared
and are arranged along the wire harness
75 similarly to the other illuminators
70 in parallel with them.
In this example, although it is advantageous in that connecting operations are
simple because the illuminators
70 are connected to ends of the branch lines
72 using connectors, there is a problem in that the illuminators cannot
be made small. Further, since the illuminators
70 are connected to the wire
harness
75 through the joint connectors
71, the branch lines
72,
and the module-side connectors
73, there is a problem in that a large number
of components are involved to result in a high total cost. Further, since the illuminators
70 are connected to ends of the branch lines, not intermediate portions
of the same in a manner similar to that in the first example, there is a problem
in that it is uneasy and troublesome to provide an additional illuminator
70.
FIG. 8 shows a third example of an related-art illuminator. The present example
is different from the second example in that a plurality of illuminators
80
is serially connected to a branch line
81 which branches from a wire harness.
Each of the illuminators
80 is constituted by a case
87 formed
by a base
84 and a cover
86 and a connecting circuit. Both of the
base
84 and the cover
86 are provided by molding a synthetic resin
material having insulating properties. An intermediate section of the branch line
81 is soldered to the connecting circuit.
In this example, a redundant part
81a of the cable
81 is
left between the adjoining illuminators
80 to facilitate the assembly of
each of the illuminators
80. However, if the redundant part
81a
is too long, the cable can be flapped by vibration of the vehicle when it is
running, which results in the problem of the generation of noises and damage of
the cable due to interference with its surroundings.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an illuminator provided
with LED chips (hereinafter, simply referred as an LED illuminator) capable of
solving the above problems, particularly to prevent a redundant part of an cable
from flapping to thereby eliminating the generation of noises and the damaged due
to interference with its surroundings.
In order to achieve the above object, according to the invention, there is provided
an LED illuminator, comprising:
a plurality of LED lamp modules, each of which comprises:
- a base;
- an LED drive circuitry, mounted on the base; and
- a cover, coupled with the base to cover the LED drive circuitry, the
LED lamp modules being stacked one on another; and
a flat cable, extending through the LED lamp modules so as to have at least one
first portion disposed outside the LED lamp modules and a plurality of second portions
disposed inside the LED lamp modules to be electrically connected to the LED drive
circuitry in each of the LED lamp modules,
wherein the first portion of the flat cable is sandwiched between the base
of an upper one of the LED lamp modules and the cover of a lower one of the LED
lamp modules.
With such a configuration, since the plurality of the LED lamp modules connected
to the flat cable are stacked one on another, the luminance of the LED lamps can
be adequately adjusted depending on the specifications of areas to be illuminated.
Since the redundant part (the first portion) of the flat cable is sandwiched between
the base of the upper module and the cover of the lower modules, the generation
of noises and damage due to flapping of the redundant part of the flat cable can
be prevented.
Preferably, an outer face of the base is formed with a groove for receiving
the first portion of the flat cable.
With such a configuration, the redundant part of the cable is securely positioned
by being contained in the groove, which prevents a transverse shift of the redundant
part. Therefore, the first portion is completely protected from interference with
its surroundings.
Preferably, the cover comprises a retainer which retains each of the
second portions of the flat cable on an inner face of the base.
With such a configuration, the flat cable can be prevented from being lifted
from the inner face of the base even when the first portion of the flat cable is
folded back to be sandwiched by the LED lamp modules.
Preferably, each of the LED lamp modules comprises a guide member disposed
on an inner face of the base to restrict a lateral movement of each of the second
portions of the flat cable.
With such a configuration, the flat cable extended along the inner and outer
faces of the base can be prevented from being damaged due to the friction caused
by the lateral movement.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent
by describing in detail preferred exemplary embodiments thereof with reference
to the accompanying drawings, wherein:
FIG. 1 is a perspective view showing an embodiment of an LED illuminator according
to the invention;
FIG. 2 is an enlarged perspective view of an groove of the LED illuminator shown
in FIG. 1;
FIG. 3 is a side view of the LED illuminator in a state in which a cover of
the same is removed;
FIG. 4 is a wiring diagram of a flat cable which is connected to the LED illuminator;
FIG. 5 is an exploded perspective view of one of LED lamp modules which constitute
the LED illuminator;
FIG. 6 is a sectional view showing an example of an illuminator according to
the related-art (a first example of the related-art);
FIG. 7 is a sectional view showing another example of an illuminator according
to the related-art (a second example of the related-art); and
FIG. 8 is a sectional view showing still another example of an illuminator according
to the related-art (a third example of the related-art).
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention will be described below in detail
with reference to the accompanying drawings.
An LED illuminator
10 is a small-sized illuminator which is provided by
stacking LED lamp modules
34 serially connected to a two-core flat cable
40 and which is used as a room light or a map light of a vehicle for illuminating
the cabin and the interior of a container for small items such as a console box,
a glove compartment, or an accessory pocket.
The plurality of LED lamp modules
34 is disposed at predetermined intervals
before they are stacked one on another such that a redundant part
41 of
the flat cable
40 is left as seen in the related-art example shown in FIG.
8. The flat cable
40 is a single cable which extends through the plurality
of LED lamp modules
34. The number of the LED lamp modules
34 connected
to the flat cable
40 may be more than two.
The LED illuminator
10 is operated by power supplied from a battery through
the flat cable
40. A junction box and a joint connector which are not shown
are connected to an upstream side of the flat cable
40. For example, the
junction box is connected to a battery through a wire harness which is not shown,
and the joint connector is connected to the junction box through the wire harness.
The LED lamp modules
34 are connected to the joint connector through the
single flat cable
40. When the junction box has the function of branching
the wire harness which is a trunk line, the flat cable
40 can be branched
from the junction box without providing the joint connector.
The junction box is a well-known electric connection box made of a synthetic
resin containing a circuit board and a wiring board and also having electrical
components such as connectors, relays, and fuses connected to the wiring board.
For example, the junction box is provided in the engine room of a vehicle or in
the neighborhood of an instrument panel thereof. The joint connector is provided
downstream of the junction box, e.g., at a front pillar or in the neighborhood
of the same.
Each of the LED lamp modules
34 is comprised of a base
12, a bus
bar circuit
35 provided with an LED chip
38, and a cover
25.
A box-shaped case is formed by the base
12 and the cover
25.
The rectangular plate-shaped base
12 is formed by molding a synthetic
resin material having insulating properties. As shown in FIGS. 2 and
5,
the base
12 is formed with an groove
23, engagement claws
16,
reinforcement ribs
20, and guide members
22 which are described later
in detail. The material of the base
12 is not limited to a synthetic resin,
and it may be formed of any other material such as hard silicone rubber or ceramics
as long as it has high insulating properties and moldability.
The flat cable
40 is constituted by one positive-side cable (power supply
line) with insulation coating and one negative-side cable (ground line) with insulation
coating which are connected in parallel with each other by a flat insulation band
provided therebetween, but two cables are separatable at a desired portion (see
FIG. 5). The flat cable
40 extends through the LED lamp modules
34
without any discontinuation while a part of the flat cable
40 is electrically
connected to each bus bar circuit
35.
The bus bar circuit
35 has a thin plate-shaped bus bar
36 which
is formed by punching a conductive substrate according to a circuit pattern. An
LED chip
38 and a constant-current diode
39 are soldered to the bus
bar
36.
As shown in FIG. 5, the conductive bus bar
36 is formed with pairs of
terminals
37 and engagement pieces
45. The terminals
37 extend upright
from an end of the bus bar
36 so that each electric wire of the flat cable
40 is press-fitted into each pair of the terminals
37 to establish
the electric contact between the power supply and the flat cable
40. Since
the terminals
37 are connected to the constant-current diode
39 and
the LED chip
38 through the bus bar
36, the power supply current
is supplied to the LED chip
38 through the constant-current diode
39.
The engagement pieces
45 are provided in some locations of the bus bar
36 as needed. Those engagement pieces
45 are inserted into recesses
21 formed on the base
12 to secure the bus bar
36 on the base
12 in a single action.
The W-shaped guide members
22 are members for keeping the flat cable
40
wired on the inner face
13a of the base
12 straight while
restricting the lateral movement thereof. Specifically, the positive-side cable
40a is held between one of the outer walls
22a and
a center wall
22b, while the negative-side cable
40b is
held between the other one of the outer walls
22aand the center wall
22b. An interval between each outer wall
22a and the
center wall
22b is made smaller than an outer diameter of each of
the cables
40a,
40b to securely hold the cables
40a,
40b on the guide member
22.
The reinforcement ribs
20 extend upright from the inner face
13a
of the base and disposed between the guide members
22 for reinforcing
the terminals
37. Each pair of the reinforcement ribs
20 is associated
with one pair of the terminals
37. Each pair of the terminals
37
is disposed between one pair of the reinforcement ribs
20 and one guide
member
22 as shown in FIGS. 3 and 5. With this configuration, the terminals
37 are prevented from being inclined by the reinforcement ribs
20
and the guide members
22 when the press-fitting of the cables
40a,
40b is performed.
The LED chip
38 is a white light-emitting diode of surface-mount type
having two terminals, i.e., positive and negative terminals on the bottom surface
thereof. The LED chip
38 used in the present embodiment has a rated current
of 20 mA and a rated voltage of 3.5V. The battery voltage is decreased by the constant-current
diode
39 and adjusted to the rated voltage of 3.5V. While the constant-current
diode
39 is advantageous in a case where a voltage fluctuates as can be
observed in a vehicle, a current-limiting resistor may alternatively be used when
there is no voltage fluctuation. The color of the LED chip
38 is not limited
to white, and it may be red, blue or green.
The LED chip
38 is characterized in that it consumes small power and has
a long life, high directivity, and high luminance. It consumes small power and
has a long life because it converts electricity into light with very high efficiency
(90%). It has high directivity and high luminance because it emits no diffuse light
unlike an incandescent lamp. The invention is not limited to an LED chip
38
as described above, and LED chips having various outputs may be used. Further,
the invention is not limited to a surface mount type LED chip
38, and a
bullet-shaped LED chip may be used.
As shown in FIG. 5, the box-shaped cover
25 is formed by molding a resin
so as to comprise a ceiling wall
26 and circumferential walls
30
which is orthogonal to and contiguous with the edges of the ceiling wall
26.
A space is defined by the ceiling wall
26 and circumferential walls
30
so as to be adapted to cover and protect the bus bar circuit
35. The circumferential
walls
30 are formed with retaining grooves
33, an window
31,
an inlet
42 and an outlet
44 for the flat cable
40. The ceiling
wall
26 is formed with retainers
43.
The engagement claws
16 extend upright from the inner surface
13a
of the base
12 in positions associated with the retaining grooves
33
formed on the cover
25. As shown in FIG. 3, a claw member
16a
is formed on a distal end of each engagement claw
16 so that the engagement
claws
16 and the retaining grooves
33 are engaged to combine the
base
12 and the cover
25 such that they will not accidentally come
apart as shown in FIG. 2.
The rectangular window
31 releases the light emitted from the LED chip
38 to the outside. The edges of the window
31 are chamfered into
slope faces
31a so that the released light is allowed to be diffused
at a predetermined angle (120 degrees in this embodiment). A reflective material
may be applied to a ceiling surface
31 of the light projecting window
31,
the surface of the ceiling wall
26 facing a top face of the LED chip
38
that constitutes a light-emitting surface
38a thereof. Thus, light
emitted from the light-emitting surface
38a is reflected by the reflective
material and emitted out of the window
31 with high efficiency.
As shown in FIG. 2, the outlet
42 and the inlet
44 are recesses
communicating the inside and the outside of the circumferential walls
30,
so that the flat cable is allowed to pass therethrough to be led into or out of
the module
34.
In this embodiment, as shown in FIG. 1, two LED lamp modules
34 connected
to the flat cable
40 are stacked one on another to constitute the LED illuminator
10. Incidentally, as shown in FIGS. 1 and 4, the flat cable
40 extends
while being sandwiched by the base
12 of the upper module and the cover
25 of the lower module. More specifically, the flat cable
40 wired
along an inner face
13a of the base
12 of the upper module
34 is led out from an outlet
42 (see FIGS. 1 and 2) and folded back
such that the redundant part
41 extends along an outer face
13b
of the base
12. The flat cable
40 is again folded back to be
led into the lower module
34 through an inlet
44. That is, as shown
in FIG. 4, the flat cable
40 is wired like a crank.
With such a configuration, since the redundant part
41 located between
the adjoining LED lamp modules
34 is sandwiched between the base
12
and the cover
25 of the LED lamp modules
34 stacked one on another,
the redundant part
41 will not be exposed to the outside, which prevents
the generation of noises and damage due to the flapping of the redundant part.
As shown in FIGS. 1 through 3, the groove
23 is formed on the outer surface
13b of the base
12 so as to contain the redundant part
41
of the flat cable
40. The groove
23 is formed with a depth equal
to or greater than the thickness of the flat cable
40 so that the redundant
cable can be completely contained. The groove
23 is formed with a width
similar to the width of the flat cable
40 so as to restrict the lateral
movement of the redundant part
41.
Thus, the redundant part
41 of the flat cable
40 will not be
exposed on the outside of the LED lamp module
34, which completely prevents
damage on the cable due to interference with the surroundings.
The retainers
43 extend from the ceiling wall
26 so as to oppose
to the outlet
42 and the inlet
44, respectively. When the base
12
and the cover
25 are combined, the tip ends of the retainers
43 press
the flat cable
40 to prevent the flat cable
40 from moving in the
longitudinal direction thereof. Further, the retainers
43 prevent the flat
cable
40 from being lifted from the inner face
13a of the
base
12 even when the flat cable
40 led out from the outlet
42
is folded back to be accommodated in the groove
23 as described the above.
As thus described, according to the present embodiment, the bus bar circuit
35
mounted on the base
12 is covered by the cover
25 to protect electrical
components such as the LED chip
38 and the constant-current diode
39
and to thereby maintain reliability of electrical connections. Since the plurality
of LED lamp modules
34 connected to the flat cable
40 are stacked
one on another, the luminance of the LED lamps can be adjusted according to the
specifications of an area to be illuminated. Since the redundant part
41
of the flat cable
40 is left between the adjoining LED lamp modules
34,
the assembling workability of the LED lamp modules
34 is improved. Since
the redundant part
41 of the flat cable
40 is sandwiched between
the base
12 of the upper module
34 and the cover
25 of the
lower module
34, the generation of noises and damage due to flapping of
the cable can be avoided.
Although the present invention has been shown and described with reference
to specific preferred embodiments, various changes and modifications will be apparent
to those skilled in the art from the teachings herein. Such changes and modifications
as are obvious are deemed to come within the spirit, scope and contemplation of
the invention as defined in the appended claims.
*
