Note: Descriptions are shown in the official language in which they were submitted.
~ID63~
The invention relates to a rear-view mirror arrangement
incorporating repeater lamps for connection in a vehicle
electrical direction indicating system.
Official statistics show conclusively that a large
S percentage of automo~ile accidents occur when drivers turn
across the stream of on-coming traffic (a left-hand turn
in North America and a right-hand turn in the U.K.) or
carry out some form of manoeuvre such as changing lane
There can be little doubt that a major factor not only
,
in these sta~istics but also in man~ other accidents is
the insufficient use by the driver of the vehicle's rear
,: view mirror either alone or combined with an insuf~icient .
use of the vehicle's direction indicators. It is thus a
common experien~e to follow a dri,ver whose right or left
.
hand directional signal flasher xemains in operation for
mile after mile.
~.1 ~ . . . .
An object of the invention is to providé an arrangement
,where the driver is encouraged to make ulL use of his .
v,ehicle's in~erior rear view mirror,and direction indicator~.
~,
.~: 20 ~y providing a rear viaw mirror incorporating ~epqa~e~
~ .. .
,~ direction indicator~lights~ It has sux~risingly be~n ~una
.. that such a combination o~ thesa two critical ~uncti~n~ . ,
, significantly enhances the ~river's use and appreciation o~
,, - : .' .
them and proviaes a positive aid to road saety. The
direction indicator lights incorporated in th~ mirror are
. ,
. .
. J~. .
".', ', "'.. ': ' ~. .',, ', ', '' . ' . . ': . , ' . . ' ,, " ~ '
. .
~L~63~35
thus brought wi-thin the range of the average driver's
peripheral vision and provide an instant warning i~, for
example, his directional signals have sel~-cancelled
prematurely. Exist.ing audible and visual flash~r indicator
units are frequently inadequate in congested traffic
conditions especially in a vehicle fitted with radio or
stereo equipment, or when a driver is negotiating a critical
road maneouvre or travelling at high speed. During all
these conditions a high degree o~ concentration is xequired
of the driver and it is thus often imprudent to look at
the dash panel to check whekher or not a directional
signal is operating. It is of course for similar reasons
that it is now proposed to fit modern fighter aircraft
with "head up" instrumant displays.
. ~ .
~ 15 It is known, for exam~le from U.S. Patent No~ 3 36~ ~34,
: '
to provide a photoelectric device in an aircraft navigation
system to vary the bias on a transistor so as automatically
-~ to vary thé brilliance of an indicati~ lamp in accordance
with the ambient light l~vel, that is the general~level
o~ light in the area of the aircra~t~ In the ~resent
.
i~vention, in contraqt, the indicator re~eater lamps in the
- mixxor are controlled as regards brillianae by a sensor ~-
arranged to see substant.ially the light directed towards
the driver's eyes. Thuq the repeater lamps will generally
be dimmed at night to avoid dazzling the driver, but will
,~ ,
! - 3
' ' . :' . .:
:';~ ' : . ' , ., ''~' , :': '., '. ,'. , . . ' :' ' ,,
.
6~695
brighten up in response to oncoming light, for ~xample
from the headlamps of oncoming vehicles, but not in response
to light direct~d towards the sides or rear of the vehicle.
It is also known from U. S. Patent ~o. 3 680 951 to
use light sensitive devices to dip a vehicle rear view
mirror automa-tically when the lights of a following vehicle
are incident thereonO Two ligh~ sensitive devices are used,
one facing to the rear o~ the vehicle and the other to one
side to~measure the ambient light level. The device operates
; 10 ~ as an on-off switch. It is in no way concerned with indicat-
ing lamps or the brilliance thereof, and provides solely a
mirror for rear viewing without any other function.
Various proposals have been made to combine direction
` indicators with external rear view mirrors; see for
-~ 15 example U.S. Patent ~o. 2 580 014 and British Patent
~o. 258 975. In these proposals the object has been to
` combine external direction indicators ~or warning other
. ~ .
road users of intended manoeuvres with an external rear
., i
view mirror. They do not provide additional, repeater lamps
~ . .. .
within the driver's peripheral vision when looking forward,
and have no provision for dealing with the variations in
the light incident on the driver's eyes.
An object of this invention is accordingly to provide
, a driver's interior rear view mirror for a vehicle
incorporating direction indicator repeater lamps and
having means for preventing said repeater lamps from dazzlin~
the driver in low levels o~ general light.
- ~ 4 ~
~ ~I"
~6365~S
Another object is to render the brilliance of the
repeater lamps dependent substantially on the light level
incident on the driver's eyes from the extexior of the
vehicle.
A rear view mirror arrangement in accordance with the
invention for use in a motor vehicle having an electrical
circuit for flashing indicators comprises a frame, a
reflective panel mounted in the frame, and a pair o~
repeater lamps mounted behind the reflective panel. Means
are provided defining windows in the re?flective? panel at
opposite ends thereof throuyh which the repeater lamps may
shine. Electxic circuit means connected to the repeater
lamps to energise the latter are arranged for connection
to said flashing indicator electrical circuit. A light
lS sensitive device is mounted behind said reflective panel
~; by means which pass a portion of the lighk striking the
rear of the mirxor arrangement within an angle of incidence
centred on an axis substantially normal to the piane of th~
re1ective panel. The light sensitive device is connected
.. . .
in said electric circuit means such that the level o
. , .
~ energisation of the repeater lamps varies with the level
s
of light striking said light sensitive device.
Other objects, features and advantages o~ the present
invention will be apparent from the following description,
given by way of example, of presently preferred
'.
., .
~, _ 5 _ :
?
~ . .
! ~
~ ' ' , , ' ~ '~ , ,' . '' , , ' . . , , ' ' '
' , ' ' ' , ' ' ~ ' ' .. ' ' " , ' ' , , '' .
!JI
~63695
embodiments thereof~
In the drawings:
Figure 1 is a front perspective view of an automobile
rear view mirror arrangement with the reflective panel
therein partly broken away;
Figure 2 is a rear perspective view of the rear view
mirror o~ Figure 1 but with the casing partly broken away;
Figure 3 is a rear per~pective view of the rear view
mixror of Figures 1 and 2;
,: .
Figure 4 is a circuit diagram for the rear view mirror
, .
arrangement of Figures 1 to 3; and
Figure 5 is an alternative circuit diagram for an
; automobile having a positive ground electrical system.
Referring particularly to Figures 1 and 2, there is
shown a rear view mirror comprisiny a plastics frame 10
;: holding a mirror glass 12 which forms a reflective panel. .
:.` :
The frame 10 comprises a ~orward peripheral portion 13
receiving the glass 12 in a groove 13a, and integral
~` ~ therewith a back plate 14 which is attached by a pivot 16
. ; 20 to a supporting pillar 17 in known manner.
f' '~ In this preferred embodiment, the mirror is a dipping
mirror, that is the pivot 16 is mounted in a member 18
.. ~ which may be pivoted about integral pivots such as 20
-
.. received in the back plate 14 by pressing on a handle 22
~ 25 to move the mirror through an angle where~y the driver is
..
~'f , : ,
-- 6 --
.
,:: . , , . , . . , - , . - , , . . . . :
.. . . . . . . . . . . .... . . ..
l!L0636~35
not dazzled by the lights of a following vehicle. Such a
mechanism is well known in the art.
In accordance with the invention, the mirror glass 12
has arrow-shaped windows adjacent both ends, one of which
may be seen in Figure 1. The windows 24 are suitably formed
by placing a mask on the reverse of the mirror glass to
expose the desire~ arrow shape and locally removing the
safety covering and silverin~ by sand blasting. It is
preferred that the windows 24 are small in xelation to the
mirror glass 12 and are provided internally with a coloured
transparent layer, suitably red in colour~ --
A miniature repeater lamp 26 (only one of which ca~
be seen in Figure 1) is mounted behind each window 24,
suitably by glueing the lamp directly to the rear of the
mirror glass 12 with a transparent epoxy resin, The
; repeater lamps 26 are connected to an electronic circuit
on a printed circuit board 28 mounted on the back plate 14
`s and via wires 29 to the electrical circuit of the vehicle,
... . . .
as will now be described.
? 20 Referrin~ to Figure 4, there is inaicated a battery 30
of a vehicle, a flasher unit ~2~ a direction indicator
switch 34, and left and right direction indicator lamps 36
and 38 respectivel~ all of which are conventional in the
- .
automobile art and there~ore not described in detail. The
lamps 26, 27 are connected in parallel with tha appropriate
.,
~ ,,
~; , . ,: , ~ -
. .
6;~6~5
vehicle direction indica-tor lamps 36, 38 respectively to
the switch 34, and each repeater lamp is connected via a
respective diode Dl, D2 to the emitter of a transistor TRl
whose collector is connected to vehicle earth (ground).
The base o~ the transistor TRl is biased by -the
voltage at the junction of a fixed resistor Rl and the
parallel combination of a variable resistor VR and a
light-dependent resistor I,DR forming a potential divider
across TR1.
ThuS, when the driver operates the right hand
direction indicator, the lamp 27 in the mirror flashes in
.
synchronism with the vehicle lamp 36, and is visible to
the driver as a red light through the appropriate window 24,
and vice versa for a lef-t turn indication.
The bias on TRl is varied by the light dependent
resistor LDR in accordance with the light incident thereon,
.
whereby the repeater lamps 26, 27 are dimmed when the incident
light level is low. VRl may be manually adjusted;to set the
minimum brilliance~
Figure 5 shows an alternative circuit ~or mounting
on the printed cixcuit board 28 ~or usa in vehicles havin~
positive earth electrical systems. It will be understood
. .
that thls is connected into the vehicle electrical system
in exactly the same manner as the circuit o~ FLgure 4~
LiXewise, the circuit o~ Figure 5 comprises the same elements
~` . ' ' . . .
- 8 -
/ -- . .
'' ' .
-.- . - ., . " : . :
. : : :, . ,:, :~: , .,:, . . . . . ~; ...... . ..
: ~ . .
. .. . : . . . .:: , .
,'..
~3~5
operating in the same manner as in Figure 4, but
connected with opposite polarity.
Returning to Figures 2 and 3, it will be seen that, in
acccrdance with the invention, the light-dependent resistor
LDR is mounted on the printed circuit board facing the
rear o~ the mirror assembly, i.e. to face the front of the
vehicle in use. An aperture 40 is formed in the back plate
14 at a location in ~ront of the LDR to permit incident
light to pass thereto. Owing to the restricted diameter
of the aperture ~0, the thickness of the back plate 14,
and the spacing between the back plate 14 and the LDR, the
latter receives incident light only within a given cone
of incidence around an axis substantially normal to the
plane of the mirror glass 12. ~hus the light incident on
the LDR is essentially the same as that incident on the
driver's eyes and the intensity of the lamps 26, 27 will
compensate for such e~ects as oncoming headlights during
the hours of darkness.
A second aperture 42 formed .in the back plate 14
allows the insertion of a screwdriver to set the variabla
resistance VR.
.,, ' ~
:' :
~. :
. ~ .
~ - g _
., .
: . , , . , , . . ,: .
. "' ' :. : '' . . .
,
:
