Radiant energy – Photocells; circuits and apparatus – Housings
Reexamination Certificate
2001-07-18
2003-09-16
Luu, Thanh X. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Housings
C250S208100, C257S434000
Reexamination Certificate
active
06621072
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle-mounted image pickup device which captures an image of vehicle surroundings by means of introducing light entering an incident window area provided on a case member which houses an image pickup main unit.
2. Description of the Related Art
FIG. 3
is a cross-sectional view of a vehicle-mounted image pickup device of this type according to an example proposed by the present inventor.
FIG. 4
is an enlarged view of the principal constituent elements shown in FIG.
3
.
As shown in
FIG. 3
, a vehicle-mounted image pickup device comprises a lightproof case member
1
made of industrial plastic; and an image pickup device main unit
3
to be disposed within the case member
1
. The vehicle-mounted image pickup device is mounted on an exterior surface of a vehicle, thereby simultaneously capturing blind spots in two directions corresponding to a driver's blind spots among vehicle surroundings. A fixture
5
is attached to the case member
1
for use in mounting the image pickup device on the vehicle.
In a conceivable preferable mode of use of the vehicle-mounted image pickup device, the vehicle-mounted image pickup device is mounted on the front end of the vehicle (e.g., on the front grill). The image pickup device captures front left-side and right-side blind spots of the vehicle.
The image pickup device main unit
3
comprises an image pickup unit
11
and a prism (reflection means) having two reflection surfaces for reflecting, to the image pickup unit
11
, a light ray
13
L entering from a left-side incident window area (i.e., a blind spot region) and a light ray
13
R entering from a right-side incident window area (i.e., a blind spot region). The image pickup device main unit
3
further comprises a hold member
17
for holding the prism
15
, and a circuit unit
19
for driving and controlling the image pickup unit
11
.
The circuit unit
19
comprises three circuit boards
21
having elements provided thereon. The image pickup
11
is disposed on the three circuit boards
21
. The circuit boards
21
are provided with an unillustrated connection section to which is connected a connector
33
coupled to a distal end of a connection cable
31
.
The prism
15
has a substantially a triangular prism shape. Of three side surfaces
15
a
through
15
c,
two side surfaces (
15
a
and
15
b
in the present embodiment) are respectively disposed opposite a left-side translucent window
35
L and a right-side translucent window
35
R provided in the case member
1
.
The light ray
13
L that has entered the case member
1
by way of the left-side window area through the left-side window
35
L enters the prism
15
. The light ray
13
L is reflected by a left-side side surface
15
a
of the prism, which serves as a reflection surface, toward the image pickup unit
11
, whereby the reflected light is introduced into the image pickup unit
11
. Similarly, the light ray
13
R that has entered the case member
1
by way of the right-side window area through the right-side window
35
R enters the prism
15
. The light ray
13
R is reflected by a right-side side surface
15
b
of the prism, which serves as a reflection surface, toward the image pickup unit
11
, whereby the reflected light is introduced into the image pickup unit
11
.
The light rays
13
L and
13
R introduced into the image pickup unit
11
enter an image pickup element
11
b
by way of an imaging lens
11
a
provided in the image pickup unit
11
. As a result, images pertaining to the left-side and right-side incident window areas are formed by the image pickup element
11
b
. The thus-captured image is output to the outside by way of a cable
31
a
of a circuit unit
19
or the connection cable
31
.
Here, in the window sections
35
L and
35
R serving as incident window areas of the case member
1
, a step
40
is formed in the edge of an opening
39
L and in the edge of an opening
39
R at the time of formation of the openings
39
L and
39
R. Translucent plates
37
L and
37
R made of glass are fitted into corresponding steps
40
. Industrial plastic having the same coefficient of expansion as that of the case member
1
can be used for the translucent plates
37
L and
37
R. However, if the windows
35
L and
35
R are flawed, images are adversely affected to a great extent. Hence, glass material which is less susceptible to flaws than industrial plastic is used for the translucent plates
37
L and
37
R.
In the vehicle-mounted image pickup device having the foregoing construction, if rainwater enters the case member
1
, dew condenses on an optical system element provided in the image pickup unit
11
, thereby deteriorating the image pickup performance. For this reason, when the translucent plates
37
L and
37
R are fitted to the steps
40
formed around the openings
39
L and
39
R of the case member
1
, the inside of the case member
1
is hermetically sealed by use of an adhesive (not shown).
Reference numeral
43
provided in
FIG. 3
designates a heat contraction tube for sealing the inside of a cylindrical section
45
opened in the case member
1
and the connection cable
31
. Reference numeral
47
designates a sealing member for sealing a clearance between the cylindrical section
45
and the outermost coating
31
b
of the connection cable
31
.
However, in relation to the waterproof structure according to the proposed example, the inside of the case member becomes hermetic in relation to the outside, thereby inducing a temperature difference between the inside of the case member
1
and the outside thereof. The external air pressure drops relative to the internal pressure of the case member
1
for reasons of the temperature difference. Because of this pressure difference, pressure is exerted on the openings
39
L and
39
R toward the outside, thereby resulting in danger of weakening the adhesive strength of the adhesive material bonding the translucent plates
37
L and
37
R to the case member
1
.
As mentioned above, when the adhesive strength exerted between the translucent plates
37
L and
37
R and the case member
1
weakens over time, the air tightness of the area of reduced adhesive strength is deteriorated. As a result, water resistance of the case member
1
is impaired. In some cases, there is a fear of the translucent plates
37
L and
37
R dropping from the case member
1
because of vehicle vibration.
SUMMARY OF THE INVENTION
The present invention has been conceived against this back drop and is aimed at providing a vehicle-mounted image pickup device which prevents occurrence of damage to an incident window area and has superior performance in preventing deterioration in water resistance.
To solve the problem set forth, the present invention provides a vehicle-mounted image pickup device which introduces light having entered into an image pickup main body housed in the case member through an incident window area formed in a case member, thereby capturing an image relating to vehicle surroundings, wherein the case member comprises
a translucent housing whose portions corresponding to the incident window regions are sealed;
a flaw-prevention translucent plate which is stacked on areas corresponding to the incident window regions of the translucent housing and is situated on the exterior surface side; and
an opaque layer formed in an area other than the area where the translucent plate of the translucent housing is disposed.
Preferably, recesses are formed in an exterior surface of the incident window regions of the translucent housing, and the translucent plates are fitted into the recesses.
Preferably, the translucent plate is bonded to the translucent housing by means of a translucent adhesive.
REFERENCES:
patent: 4488141 (1984-12-01), Ohlenforst et al.
patent: 5120920 (1992-06-01), Moriike
patent: 5756988 (1998-05-01), Furuta
patent: 6122009 (2000-09-01), Ueda
Autonetworks Technologies Ltd.
Luu Thanh X.
Oliff & Berridg,e PLC
LandOfFree
Vehicle-mounted image pickup device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle-mounted image pickup device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle-mounted image pickup device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3027353