MXPA00007966A - Dimming mirror assembly - Google Patents

Abstract

A dimming mirror assembly (10) has a housing, a reflective member (20), a transparent member (28), a light reducing medium (36), and an actuating mechanism for introducing and evacuating the light reducing medium (36) disposed in a gap between the transparent member (28) and the reflective member (20). The reflective member (20) and the transparent member (28) are carried by the housing. At least one of the transparent member (28) and the reflective member (20) is moveable relative to the other. The amount of light transmitted to and reflected from the reflective member (20) is a function of the volume of light reducing medium (36) therebetween, the volume being variable by effecting relative movement between the reflective (20) and transparent members (28). The controlling mechanism may include an actuating mechanism for effecting the relative movement between the reflective (20) and transparent members (28).

Description

DIMMING MIRROR ASSEMBLY FIELD OF THE INVENTION The present invention relates to a darkening mirror assembly having an improved mechanism for effecting a change in the quantity, by means of which the reflected light from the mirror darkens.

BACKGROUND OF THE INVENTION A significant problem with driving at night is that rear-view mirrors of the vehicle can reflect the headlights of a rear vehicle in the eyes of the driver, thus deteriorating the driver's vision. A conventional solution to this type of problem, used mainly with the mirrors, interior, central mirrors, is to use a prism mirror with a lever of change in the housing of the mirror. The shift lever can be moved between a diurnal position, which provides a normal intensity reflection, direct from the mirror surface, and a night position that provides a reduced intensity reflection. With the intensity of the light reflected to the driver, REF .: 122415 the intensity of the reflected headlights of the rear vehicles is insufficient to impair the driver's vision. Another proposed method for reducing the intensity of reflected light from a rearview mirror is to employ a mount wherein a reflective member and a transparent member are mounted in a sealed housing with a gap therebetween. A light absorbing medium, liquid, is placed between the reflective and transparent members, and this means, by absorbing a portion of the light transmitted to the reflective member and a portion of the light reflected by the reflective member, reduces the intensity of the light finally reflected to the driver. The amount of light reduction depends on the amount of the light reducing medium between the transparent and reflective members. The transparent and reflective members can be moved with respect to each other to vary the size of the spacing between them, thereby varying the amount of light reducing medium between the members and the amount of light intensity reduction achieved. That is, when the size of the gap is reduced, the light reducing means is removed from the gap, and when the gap is enlarged, it is pulled towards the separation of the light reducing medium. Different mechanisms have been proposed in the patent literature to effect relative movement between the transparent and reflexive members. For example, U.S. Patent No. 3,198,070 discloses a solenoid mechanism and an electromagnetic mechanism for moving a mirror within a housing to vary a spacing between the mirror and a glass front of the housing. U.S. Patent No. 3,567,312 discloses a daytime mirror drive mechanism in which a chamber between a diaphragm and a glass is filled with a fluid light control means, and a pressure chamber is placed within the housing. A spring inside the chamber deflects the diaphragm, to which it joins the mirror, in a position separated from the glass. When the pressure chamber is evacuated, the spring is compressed and the diaphragm moves forward to press the mirror into the glass. U.S. Patent No. 3,233,515 discloses a rearview mirror in which a mirror control diaphragm is deflected with a spring and attached to a cable extending to a control position accessible by the driver and used to manually move the mirror against the inclination or deviation of the spring. Several references describe mechanisms by which a pump is used to force a light attenuating medium between the glass and the mirror. For example, U.S. Patent No. 3,259,017 discloses a system in which a pump mechanism is used to selectively force a light-darkening fluid between the mirror and the glass. U.S. Patent Number 4,054,374 discloses a mirror attached to a flexible diaphragm. A fluid can be pumped between the mirror and the lenses to form a separation between these, the mirror that can be moved in the flexible diaphragm. U.S. Patent No. 4,726,656 discloses a mirror in which a light attenuating fluid can be forced between the reflecting plate and a window plate. Several different pump mechanisms are described. The mechanisms described in the above patents are expensive, technically difficult to employ, or otherwise impractical. For these reasons, these mechanisms have found little commercial acceptance, if they have one. Accordingly, there is a commercial need for a dimming mirror assembly employing simpler and less expensive versions of the mechanisms described in the aforementioned patents or simpler and less expensive alternatives to the mechanisms mentioned above.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a dimming mirror assembly that is simpler and less expensive to manufacture in conventional dimming mirror assemblies that have been proposed or are currently available. In accordance with one aspect of the present invention, a dimming mirror assembly is provided for a vehicle, which comprises a housing constructed and arranged to be mounted on a vehicle in a position to be seen by the driver. A reflective member and a transparent, cooperating member jointly define a mirror within the housing to provide the driver viewing the housing with a rear view with respect to the vehicle. The mounting structure mounts the reflective and transparent members in the housing in juxtaposition with respect to each other for relative movement towards and away from each other to define a variable size separation between the reflective and transparent members. A light reducing means is placed within the gap and is constructed and arranged to reduce the intensity of the light in the rear view reflected by the reflective member through the transparent member to the driver. The amount of light intensity reduction is directly related to the amount of the light reducing medium placed between the reflective and transparent members which, in turn, is directly related to the size of the separation. A drive mechanism is operatively associated with the reflective and transparent members and is constructed and arranged to effect relative movement between the reflective and transparent members. The drive mechanism includes a deformable member having a portion thereof coupled to either the transparent member or the reflective member and another portion thereof fixed with respect to the housing. The deformable member is constructed and arranged to deform in the application of voltage thereto. In this manner, the portion of the deformable member coupled to either the transparent member or the reflective member is moved with respect to the portion of the deformable member fixed with respect to the housing as the deformable member changes from a non-deformed condition to a deformed condition. In this way, the deformable member imparts a relative movement between the reflective and transparent members to vary the size of the spacing between them and thus to vary the amount of the light reducing means placed between the reflective and transparent members and the amount of reduction of light intensity of light reflected through the transparent member to the driver. A voltage regulating mechanism is constructed and arranged to regulate the voltage applied to the deformable member of the drive mechanism in response to an external input. In this way the voltage regulating member regulates the deformation of the deformable member to regulate in this way the size of the separation between the reflective and transparent members and the amount of light intensity reduction of the light reflected through the transparent member to the driver. sensitive to external input. According to another aspect of the invention, a dimming mirror assembly is provided for a vehicle having a housing constructed and arranged to be mounted on a vehicle. A reflective member and a transparent, cooperating member jointly define a mirror within the housing. The reflective and transparent members are mounted in the housing in juxtaposition with respect to each other for relative movement towards and away from each other to define a separation of variable size between the reflective and transparent members. A light reducing means communicates with the separation. A driving mechanism includes a deformable member having a portion thereof coupled to at least one of the reflective and transparent members and another portion thereof fixed with respect to the housing. The deformable member deforms on application of the voltage thereto to apply relative movement and vary the size of the spacing and sensitively vary an amount of the light reducing means placed between the reflective and transparent members. A voltage regulating mechanism is connected to the drive mechanism to regulate the voltage applied to the deformable member, thus regulating the amount of light reflected by the reflective member.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a darkening mirror assembly of the present invention shown mounted as a rear view mirror, central inside a motor vehicle; Figure 2 is a schematic, cross-sectional view of the dimming mirror assembly of the present invention taken through line 2-2 of Figure 1 and showing the dimming mirror assembly in a non-dimming condition; Figure 3 is a schematic cross-sectional view similar to that of Figure 2, but showing the darkening mirror assembly in a darkening condition; Figure 4 is a schematic cross-sectional view similar to that of Figure 2, but illustrating a second embodiment of the present invention; Figure 5 is a schematic cross-sectional view similar to that of Figure 2, but illustrating a third embodiment of the present invention; and Figure 6 is a schematic cross-sectional view similar to that of Figure 2, but illustrating a fourth embodiment of the present invention; and Figure 7 is a schematic cross-sectional view similar to that of Figure 2, but illustrating a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention relates to a dimming mirror assembly, generally indicated at 10 in Figure 1. In Figure 1, the dimming mirror assembly 10 is mounted as a rear view mirror, centrally located within of a motor vehicle, where you have a preferred application. The dimming mirror assembly of the present invention can also be incorporated in an outer, side assembly 4. Figure 2 is a sectional, longitudinal view taken along the line 2-2 in Figure 1. As shown in Figure 2, the mirror assembly 10 includes a housing 12, which is preferably made from a plastic or metallic material and is built and arranged to be mounted on the vehicle in a position to be seen by the driver of the vehicle. In the embodiment shown, the housing 12 comprises an annular or peripheral wall 14, a rear wall 16. These portions 14 and 16 of the housing 12 can be separate units adhered or otherwise affixed to each other, or they can constitute an integrally molded structure or formed in another way. The housing can be of any desired shape corresponding to the desired shape of the mirror, such as the rectangular, general, conventional shape for the rear view mirror, central, interior. A reflective member 20 that is carried within the housing 12. Preferably, the reflective member 20 comprises a mirror glass 22 having a coating 24 of reflective surface. However, it can be appreciated that, the reflective member 20 can be of any known type, such as a highly reflective metallic structure. A transparent member 28 can also be carried by the housing 12 and cooperates with the reflective member 20 to define a mirror by allowing incoming light to pass through this to be incident on the reflective member 20 in a particular manner in the present embodiment, in the reflective coating 24 of the mirror glass 22. The transparent member 28 also allows light reflected by the reflective member 20 to pass through it and outwardly from the mirror assembly 10. The mounting structure mounts the reflective member 20 and the transparent member 28 within the housing 12 in juxtaposition with respect to each other with a spacing G (see Figure 3) defined therebetween. The mounting structure allows relative movement between the reflective member 20 and the transparent member 28 towards and away from one another to vary the spacing between the members. While the transparent member is preferably clear glass, it is contemplated that it may also comprise clear plastic, or a slightly dyed material. In addition, as will be appreciated in greater detail below, it may be desired to provide anti-reflective coating on the outer surface 30 of the transparent member.

In the embodiment shown, the transparent member 28 cooperates with the housing 12 to define a sealed enclosure that is constructed and arranged to contain a fluid. A light reducing means 36 is placed inside the housing 12. The medium 36 is preferably in the form of a liquid and can be placed inside the reflective member 20 and the transparent member 28 (see for example, Figure 3) to reduce the amount of incoming light transmitted from the transparent member 28 to the reflective member 20. In addition, the light reducing means 36 reduces the amount of reflected light transmitted from the reflective member 20 to the transparent member 28 to be transmitted out of the mounting 10. of a mirror The amount of incoming light that is reflected back from the mirror is a function of the amount (or thickness, over the distance) of the light reducing means 36 placed between the reflective member 20 and the transparent member 28. As a modality Preferred, the light reducing member 36 is simply an antifreeze fluid, such as that which can be used for the windshield washer fluid. The antifreeze fluid may also be of the type used in a radiator for a motor vehicle, although non-toxic fluids are preferred. The fluids may comprise polyethylene glycol, polypropylene glycol, or butanol. In this mode, an Indigo dye can be added to the fluid to give a bluish tint that acts as a filter that transmits light with a blue wavelength through it. It can also be appreciated that the greater the distance between the transparent member 28 and the reflective surface of the reflective member 20, the greater the amount of the light reducing member between the transparent member -28 and the reflective member 20 will result in this way a greater amount of light that is absorbed or dissipated by the light reducing means 36, such that less light will be reflected out of the mirror assembly 10. It should be appreciated that the light reducing means 36 can be any means that will reduce the capacity of transmission of light passing through it, and which may be displaced from between the transparent member 28 and the reflective member 20, or may be otherwise altered to reduce the light reducing character thereof. As another example, a relatively fine, black particulate matter can be held in suspension within a fluid or gel that can be placed between the reflective member 20 and the transparent member 28. This particulate matter is capable of absorb or dissipate the light instead of allowing it to be transmitted through it. As will be appreciated, the light reducing means 36 can be displaced from between the transparent member 28 and the reflective member 20 so as to avoid a darkening effect. In particular, a control mechanism 40 is constructed and arranged to control the amount of light reducing means 36 placed between the reflective member 20 and the transparent member 28 to thereby control the amount of incoming light that will be reflected back from the 10 mirror assembly. In the embodiment illustrated in Figures 2 and 3, the control mechanism 40 is in the form of a solenoid drive mechanism. In particular, the solenoid mechanism comprises a solenoid backing 42 fixed to the rear wall 16 of the housing. The control mechanism 40 further includes a spiral winding 44 for conveying a current through it and which is secured to the solenoid backing 42. The control mechanism 40 further includes a solenoid front 46, which is fixed by adhesive or the like to the rear side of the reflective member 20. The solenoid front 46 is made of a magnetic or ferrous material. The solenoid backing 42 has a central depression 48 defined surrounding the surface 50. the solenoid front 46 has a central, projecting portion 52 which is received within the depression 48 and is positioned on the sliding surface which contacts the surfaces 50. When the mirror assembly 10 is in the configuration illustrated in Figure 2, where there is minimal separation between the reflective member 20 and the transparent member 28, there is maximum reflection of the incoming light back through the transparent member 28. In this configuration, there is a predetermined separation g, between the solenoid front 46 and the solenoid back 42. Although Figure 2 shows a configuration in which there is no separation between the reflective member 20 and the transparent member 28, in the preferred embodiment of the present invention, the reflective member 20 and the transparent member 28 never actually contact each other. , because, due to the fluid pressure between the contact members, a large amount of force will be required to separate the members. Preferably, the spacing G between the reflective member 20 and the transparent member 28 is varied to be within a range of 0.3-2.0 mm. The deflection or inclination structures, such as a plurality of leaf springs 56, are fixed to the housing 12 and deflect the solenoid front 46 and the reflective member 20 fixed thereto in a direction toward the transparent member 28, to provide an arrangement wherein the reflective member 20 is normally deflected in a minimized obscuration effect position. When the user attempts to obscure the reflectivity of the mirror assembly 10, the user activates a manually operated switch 11 connected to a power source (not shown) to apply a current through the scroll winding 44. The current through the spiral winding 44 applies a tractive magnetic force to the solenoid front 46 to move the solenoid front 46 and the reflective member 20 attached thereto in a direction away from the transparent member 28 against the deflection of the leaf springs 56. As a result, the light reducing means 36 is displaced between the solenoid front 46 and the solenoid backing 42 and moved to a gap G between the reflective member 20 and the transparent member 28. The spacing G between the reflective member 20 and the transparent member 28 according to this embodiment will be the same distance as the separation g, which previously existed between the solenoid front 46 and the solenoid back 42. The distance of this separation G according to this mode controls the amount of the light reducing means placed between the reflective member 20 and the transparent member 28. Because the separation is not existent, the amount of the light reducing medium between the member reflective and the transparent member is not noticeable to anyone. Where there is minimal or non-existent separation between the reflective member 20 and the transparent member 28, there is a maximum reflectivity of the mirror assembly 10. When the gap G between the reflective member 20 and the transparent member 28 is at a maximum, there is a minimum transmission capacity through the mirror assembly, and in this way the light reflection is reduced to a minimum. When the current through the spiral winding 44 is terminated, the leaf springs 50 are capable of deflecting or tilting the solenoid front 46 and the reflective member 20 back toward the transparent member 28 to allow maximum transmissibility and reflection of the assembly 10. Instead of energizing the spiral winding 44 by the use of a manually operated switch, the present invention contemplates that the current to the spiral winding 44 can be provided automatically by the use of a sensor switch. which detects the darkening conditions. More specifically, it is known in the art to provide automatic dimming control based on the relative brightness in a forward direction of a central rear-view mirror against the backward brightness of the central rear-view mirror. In this way, for example, when the sensor detects that there is something greater than a threshold difference in the amount of brightness coming from the rear of the vehicle compared to the forward brightness of the vehicle (e.g., as caused by the headlights of a rear vehicle), the sensor will send a signal to the spiral winding 44 to activate the darkening effect. If a sensor switch is used to control the dimming, an override switch, manually operated in conjunction with the sensor can be provided to allow the sensor to be overcontrolled. The operation of the device switching mechanisms in the In the context of controlling the current to the spiral winding 44 of the embodiment of the present invention shown in Figures 2 and 3, it will be readily appreciated that the switching mechanisms described herein can be operated with any of the mounting modes of powered dimming. with energy described in this specification. As an alternative to the solenoid assembly of this embodiment, the control mechanism 40 may comprise any mechanical or electromechanical control mechanism that is capable of controlling the amount of light reducing means placed between the reflective member 20 and the transparent member 28. For example, the control mechanism may simply comprise a bidirectional control (not shown) having a screw thread tree that moves the reflective member 20 towards and away from the transparent member 28. In Figure 5, another alternative contemplated for the mechanism is shown. of control. A driving mechanism includes one or more deformable members constructed and arranged to effect relative movement between the transparent member 28 and the reflective member 20. As illustrated in Figure 5, the deformable members of this embodiment comprise an array of wires 60 of shape memory alloy (SMA) joined between the mirror glass 22 and the rear wall 16. Here, the solenoid front is replaced by a single mirror backrest 47 and the solenoid backing is replaced by a housing booster 43. When current is applied through the SMA wires 60, the wires 60 are deformed (i.e., shortened) to move the reflective member 20 toward the back wall 16 as each wire 60 changes from a non-deformed condition to a deformed condition , or shortened. Also as illustrated in Figure 5, the leaf springs 56 can be replaced by an O-ring filled air-filled don 62, or other biasing or deflecting structure, to deflect or tilt the reflective member 20 toward the transparent member 28 When the current is terminated through the SMA wires, the wires are allowed to extend, and the O-ring 62 moves the reflective member 20 back toward the transparent member 28. The energy can be controlled to the wires 60. of SMA by a manually operated switch 11 or by a sensor switch as described above. The SMA wires 60 may be formed of a nickel / titanium alloy with low hysteresis such as wires commercially available from Raychem Corporation, which is based at Menlo Park, California, USA. Nickel / titanium wires manufactured and commercially available from Dynalloy, Ine of Irvine, California, USA under the trademark Flexinol.RTM. Can also be used. The properties and general characteristics of shape memory alloy wires are well known to those skilled in the art. When heated through a specific temperature range of the alloy, the shape memory alloy is used in a phase transition from a martensitic phase to an austenitic phase in which the wire contracts to a memory position, applied a pushing force as it contracts to move the reflective member away from the transparent member. When the wires are turned off, the wires are cooled and can easily be lengthened by the leaf springs or the 0 62 ring that moves the reflective member back to the transparent member. The wires 60 must construct and arrange so that they undergo a linear translation of the same distance so that the reflective surface of reflective member 20 remains parallel to transparent member 28. As an alternative embodiment, as illustrated in Figure 4, the control mechanism may be a manually engageable member 66 that is fixed to the reflective member 20 and extends rearwardly through the rear wall 16 to be manually engaged. This embodiment, the manually engageable member extends through the back wall 16 in sliding sealed engagement to prevent any fluid constituting the light reducing means 36 from escaping from the housing 12. The manually engageable portion 66 can move inwardly and out to alter the separation between the reflective member 20 and the transparent member 28 and thereby control the amount of light reducing means 36 therebetween. The frictional sliding engagement between the manually engageable member and the rear wall 16 of the housing retains the reflective member 20 in the position in which it moves. In this embodiment, no springs or members of deflection or inclination are provided. It should also be appreciated that the present invention contemplates that an infinite number of adjustments can be provided to the separation between the transparent member 28 and the reflective member 20. while in the first embodiment using a solenoid coil for the control mechanism , as illustrated in Figures 2 and 3, there can be only one blackout and no blackout position, it is contemplated that the G separation can be controlled more accurately. For example, the solenoid control assembly can use a material for the use of the solenoid having a high magnetic permeability, but a low cohesive force. This material may comprise Permalloy, silicon steel, or a polymer mixed with a magnetic charge. With this material, the relationship between the magnetic field and the winding current must approximate the linearity. At a given current value, the return force of the spring must balance the attractive magnetic force, and the movable member (eg, the reflective member) must be maintained in the intermediate equilibrium position. In this way, the volume of the light reducing means 36 between the transparent member and the reflective member can be controlled by varying the current between the spiral winding 44. Furthermore, with the manually operated control mechanism described above, it is possible to manually place the reflective member 20 at various distances from the transparent member 28 to more accurately control the darkening effect of the mirror assembly 10 as compared to the control mechanism. simple on / off provided by the solenoid coil. As another example, a motor or rheostat can be controlled very precisely (potentiometer) stepwise, bidirectional to move the reflective member 20 to provide an infinite degree of adjustment, or selected adjustment intervals, of the separation between the reflective member 20 and the transparent member 28. As a further alternative, as illustrated in FIG. 6, the control mechanism may be in the form of a peristatic pump 70 or electric pump communicating with the gap g, between the reflective member 20 and the transparent member 28. In this embodiment, the light reducing means 36 comprises a fluid that can be placed between the reflective member 20 and the transparent member 28. however, no light reducing means is placed in the space 37 before the reflective member 20 and the back wall 16. In contrast, to effect the darkening, the pump 70 will pump the light reducing means 36 between the reflective member 20 and the transparent member 28 to force the reflective member to move back away from the transparent member e 28 to effect the darkening. As shown, the reflective light member is provided with a depression 74 to ensure that the fluid discharged by the pump 70 will be received between the reflective member 20 and the transparent member 28. When no darkening occurs, the pump sucks or evacuates the fluid of the light reducing means of the separation between the transparent member 28 and the reflective member 20. the evacuation of the light reducing fluid 36 causes the reflective member 20 to withdraw towards and be in contact with the transparent member 28. Another mechanism Alternate control also comprises a drive mechanism that employs a deformable member to effect relative movement between the reflective member 20 and the transparent member 28. As illustrated in Figure 7, a drive mechanism for the mirror assembly 10 includes a deformable member comprising a piezoelectric actuator 80 positioned within the space 37 between the reflective member 20 and the wall rear 16 and operatively coupled to the reflective member 20 to effect relative movement between the reflective member 20 and the rear wall 16. The general properties and characteristics of the piezoelectric actuators are known. In the illustrated embodiment, the actuator 80 comprises a wafer laminate 82 of two independent piezoelectric elements 84, 86, stacked together. Each element 84 and 86 is wired separately by wires 88 and 90, respectively. The elements 84, 86 are driven with a driving voltage in opposite directions so that one of the elements 84 and 86 extends and the other element 84 and 86 contracts. Accordingly, the wafer laminate 82 is bent when a drive voltage is applied to both elements 84, 86 simultaneously. These linear actuators, commonly known as "biraorfos" are commercially available from companies such as Active Control Experts (ACX) of Cambridge, Massachussetts. One end 92 of the wafer laminate 82 is secured in a cantilever fashion to the peripheral wall 14 of the housing 12 (or is otherwise fixed with respect to the housing 12), and the opposite end 94 of the wafer member 82 is secured to the back or back of the reflective member 20. In this way, when a driving voltage is applied to the wafer member 82, thereby causing it to deform by bending, as shown in dotted lines in Figure 7, the movement relative between the reflective member 20 and the transparent member 28 is effected. When the drive voltage is cut, the wafer laminate 82 returns to its non-deformed condition. A deflection or inclination structure, such as leaf springs or a 0-ring (not shown) may be provided to deflect or tilt the reflective member 20 toward the transparent member 28. As an alternative to leaf springs or a ring in OR, the elasticity of the actuator itself can deflect or tilt the reflective member 20 towards the transparent member 28. The energy to the wafer laminate 82 can be controlled by a manually operated switch or with a sensor switch as described above. In the illustrated embodiment, the reflective member 20 is in close proximity to the transparent member 28 when the wafer laminate 82 is not flexed, to effect little or no darkening. The reflective member 20 moves away from the transparent member 28 when the wafer laminate 82 flexes in the application of a voltage thereto. It can be seen that the piezoelectric actuator 80 could be configured so that the reflective member 20 is separated from the transparent member 28 when the wafer laminate 82 does not bend, and the reflective member 20 moves toward the transparent member 28 when the product Wafer laminate 82 is doubled in the application of a voltage to it. In the preferred embodiment, the end 94 of wafer laminate 82 is attached to the back of the reflective member 20 by means of a wire clip 100 comprising a first portion 104 attached to the back and the reflective member 20, and a second portion 102 extending away from the rear surface of the reflective member 20 and connected to the end 94 of the wafer laminate 82. In an alternative configuration for the piezoelectric actuator, the wafer laminate can have a length encompassing width of the housing 12. the opposite ends of the wafer laminate can be secured to the peripheral wall 14 of the housing 12, and an intermediate portion of the wafer laminate can be attached to the back of the reflective member 20. Alternatively, the opposite ends of the wafer laminate can be secured to the back of the reflective member 20 and an intermediate portion of the product laminate can be attached to the rear wall 16 of the housing 12. In any case, it can be seen that the folding of the wafer laminate product due to the application of a voltage thereto will effect the relative movement between the reflective member 20 and the transparent member 28. In addition, while the preferred embodiment shown in Figure 7 only provides an individual actuator to limit the cost and complexity of the assembly, two or more actuators acting in parallel or in series can be used. The piezoelectric actuators used by the inventor require direct current of 200 volts at low energy to achieve full operation. Accordingly, a piezoelectric actuator will include the drive circuitry to convert a 12 volt supply of the vehicle to a low voltage supply of 200 volts for the actuator. It is now contemplated that this drive circuit assembly could be provided as a circuit board that is attached to or integrally integrated into the wafer laminate product.

Piezoelectric actuators provide certain advantages over other types of actuators. Typically, piezoelectric actuators are less sensitive to temperature, require less energy, and have a faster response time than other power driven actuator mechanisms. The present invention further contemplates that the reflective member 20 can be stationary, and that the transparent member 28 will move toward the reflective member 20 to avoid the darkening effect, and move away from the reflective member 20 to create the darkening effect. This can be achieved with any of the control mechanisms mentioned above. With respect to the light reducing means 36, it is preferred to use an antifreeze fluid so that it does not freeze in cold weather temperatures. It is desired that the fluid maintain a substantially constant viscosity and independent of temperature. The fluid must remain at a relatively low viscosity to allow easy and rapid deployment. In addition, the fluid is also self-wetting preferably glass to cover the entire glass surfaces and completely fill the gap between the reflective member 20 and the transparent member 28. It should also be noted that the darkness of the fluid will determine how thick it is a separation is to be provided between the transparent member 28 and the reflective member 20. For a darker fluid, a thinner spacing will be used, and for a lighter fluid, a larger spacing will be required. It should be appreciated, however, that it is desirable to make the separation between the transparent member 28 and the reflective member 20 as thin as possible to achieve the requisite dimming condition in order to reduce the deployment time and also to thin out the total thickness of the mirror assembly. In an alternative embodiment (not shown) it is contemplated that the light reducing means be in the form of a solid, such as a relatively thin, transparent sponge foam material. In this embodiment, when the foam material is compressed, it becomes less transmitting to provide a darkening effect. In this way, in this embodiment, the separation between the transparent member 28 and the reflective member 20 is reduced to effect the dimming and is increased to effect the increased transmissibility. With respect to the transparent member 28, it is desired that the transparent member 28 be as thin as possible in order to reduce any refraction of light caused in this way. By providing a thin glass material for the transparent member 28, less refraction will be provided, and in this way a greater reflection of light. In addition, because less refraction occurs, the possibility of a "double image" will be avoided or reduced. In this regard, providing a thinner spacing between the reflective member 20 and the transparent member 28 will also reduce any reflective effect during the darkening condition. Thus, it is desirable that the light reducing means 36 be darker or highly reactive to create a large change in the transmission of light with a minimum separation between the transparent member 28 and the reflective member 20. Again, this will make it thinner to the mirror assembly 10 as a whole, and will reduce any "double image" effect. It will also be mentioned that it may be desirable to provide an anti-reflective coating on the outer front surface 30 of the transparent member to further reduce any double image effect. In addition to the improved operation, simplicity of manufacture and increased effectiveness in the cost of the present invention, a further advantage of the arrangement illustrated in Figures 2 and 3 is that, in the case of a power failure of the mirror system, there will be no current input through spiral winding 44. As a result, any kind of power failure with the mirror assembly 10, the mirror assembly 10 will automatically fail its non-blackout condition by the operation of the leaf springs 56, or other means of deflection. It should be appreciated that instead of using the leaf springs 56 of Figures 2 and 3, or the soft O-ring of the tubular type having air contained therein, as shown in Figure 5, a rubber ring can be used. Closed cell foam that can remove a liquid environment. This O-ring or resilient material ring can be placed in an annular manner within the spacing between the solenoid backing 42 and the solenoid front 46 to apply a uniform and concentric load with respect to the reflective member to ensure that the reflective member 20 remains parallel with the transparent member 28 at any time. It is also desirable that the support surface between the reflective member and the housing be distributed in a relatively uniform and wide manner based on retaining the parallel relationship between the transparent member 28 and the reflective member 20. As mentioned above, the mechanisms of controls described herein can be used in both a central, interior mirror as well as a side, exterior mirror. In addition, a power-operated dimming mechanism provided in the outer, side mirror assembly 4 can also be activated by means of the switch 11 mounted to the inner, central mirror. Accordingly, the darkening mechanisms in both the inner mirror 10 and the inner mirrors 4 can be activated by means of the individual switch 11. An alternative arrangement is to employ a conventional prism mirror such as the rear, center, bottom mirror and a mechanism Control system powered with power in the side, exterior mirrors. The activation switch for the power-operated control mechanism is coupled to the shift or switching lever of the interior mirror, and the activation switch is constructed and arranged so that the control mechanism of the exterior mirror is activated to darken from this mode the side mirror when the shift lever of the central mirror moves to the night position, and the control mechanism is deactivated to thereby return the side mirror to normal reflection when the shift lever of the central mirror moves to the day position. The dimming mirror assembly of the present invention, provided either in the center, interior or side, exterior mirrors, can be provided as additional equipment in the vehicle or as a post-sale upgrade product. As a post-sale upgrade product, the assembly can be provided as a replacement mirror assembly, complete with a switching or switching mechanism and the appropriate wiring to connect the assembly to the vehicle's power source. Alternatively, the darkening mirror may be provided as a darkening panel unit comprising a transparent member and a reflective member mounted in a housing for relative movement, a control mechanism contained within the housing for effecting relative movement, and a light reducing means also contained within the housing. Proper wiring and switches are provided with the darkening panel unit. The panel unit can be secured, such as by adhesive pads or the like, to the glass surface of the existing mirror assembly. For side, exterior mirrors in particular, existing mirror glass and panel backing can be removed from the mirror assembly, and the blackout panel unit can be operatively connected to the motor driver or remote control mechanisms of the assembly existing mirror. The after-sale upgrade product, side mirror will include, in addition to the darkening panel unit, the wiring to connect the unit to the vehicle's power source and a switch that is to be attached to the central, exterior mirror assembly and operatively coupled to the change or mirror switching lever of prism as described above. While the invention has been described in conjunction with what is currently considered to be the most practical and preferred modalities, it is to be understood that the invention is not limited to the described modalities, but on the contrary, it is proposed to cover several modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (24)

1. A dimming mirror assembly for a vehicle, comprising, a housing constructed and arranged to be mounted on a vehicle, a reflective member and a cooperating transparent member together define a mirror within the housing; the reflective and transparent members are mounted in the housing in juxtaposition with respect to each other for relative movement towards and away from one another to define a variable size separation between the reflective and transparent members; a light reducing means disposed within the separation; a drive mechanism for effecting relative movement between the reflective and transparent members to vary the size of the spacing between them and to vary appreciably a quantity of the light reducing means, disposed between the spacing; and a voltage regulating mechanism communicated with the drive mechanism; characterized because: the driving mechanism includes a deformable member formed of an electrically deformable material adapted to deform in response to a voltage application thereto, the deformable member having a portion therein that engages at least the reflective and transparent members and another portion thereof coupling a surface within the housing, so due to the application of voltage to the electrically deformable material the deformable member is deformed to effect relative movement between the reflective and transparent members; Y the voltage regulating mechanism is adapted to regulate the voltage applied to the electrically deformable material in order to control the size of the separation between the reflective and transparent members and the amount of the light reducing means disposed within the separation.

2. The dimming mirror assembly of claim 1, characterized in that the transparent member is constructed and arranged to cooperate with the housing to define a sealed enclosure for containing a fluid comprising the light reducing means.

3. The dimming mirror assembly of claim 1, characterized in that the transparent member is fixed with respect to the housing and the reflective member is allowed to be movable with respect to the transparent member.

4. The dimming mirror assembly of claim 1, characterized in that it further comprises the deflection structure constructed and arranged, so that the relative movement between the reflective and transparent members resulting from the application of voltage to the deformable member accentuates in an increased manner the Deflection structure so that a decrease in or removal of voltage applied to the deformable member, the deflection structure applies a deflection force that effects an opposite relative movement between the reflective and transparent members.

5. The dimming mirror assembly of claim 4, characterized in that the deformable member and the deflection structure are positioned so that the relative movement effected by the application of voltage to the deformable member is the reflective and transparent member that moves away from one the other towards a position of maximum separation, and the opposite relative movement effected by the deviation structure is the reflective and transparent member that moves towards each other towards a minimum separation position.

6. The dimming mirror assembly of claim 4, characterized in that the deflection structure couples the reflective member and is constructed and arranged to apply the deflection force to the reflective member to move the reflective member relative to the transparent member to effect the relative movement opposite.

7. The dimming mirror assembly of claim 5, characterized in that the deflection structure couples the reflective member and is constructed and adapted to apply the deflection force to the reflective member to move the reflective member relative to the transparent member to effect the relative movement opposite.

8. The dimming mirror assembly of claim 4, characterized in that the deflection structure includes a flexible leaf spring.

9. The dimming mirror assembly of claim 4, characterized in that the deflection structure includes an O-ring filled with air.

10. The dimming mirror assembly of claim 4, characterized in that the deflection structure includes an O-ring of flexible material.

11. The dimming mirror assembly of claim 10, characterized in that the flexible material is closed cell foam.

12. The dimming mirror assembly of claim 1, characterized in that the deformable material comprises one or more shape memory alloy wires.

13. The dimming mirror assembly of the rei indication 12, characterized in that the shape memory alloy wire is an alloy formed of nickel / titanium.

14. The dimming mirror assembly of any of claims 12-13, characterized in that the housing includes a housing reinforcing member and one or more shape memory alloy wires are affixed to the reinforcing member.

15. The dimming mirror assembly of claim 1, characterized in that the deformable member comprises a piezoelectric actuator.

16. The dimming mirror assembly of claim 15, characterized in that the piezoelectric actuator includes a laminate disposed between a pair of piezoelectric elements; a portion of the laminate is fixed with respect to the housing and another portion of the laminate is attached to one of the reflective and transparent members, so that the flexure of the laminate effects movement relative movement between the reflective and transparent members; The mechanism that regulates the voltage applies the respective opposite voltages to the piezoelectric elements to expand one of the elements and contract the other of the elements whereby the flexing of the laminate effects the relative movement.

17. The dimming mirror assembly of claim 16, characterized in that a portion of the laminate is a terminal portion of the laminate that is cantilevered to the housing and the portion of the laminate is an opposite end portion of the laminate that is attached to the reflective member .

The dimming mirror assembly of claim 16, characterized in that one portion of the laminate is a middle portion of the laminate that is joined to the housing and the other portion of the laminate includes a pair of opposite end portions of the laminate each of which is they join the reflective member.

19. The dimming mirror assembly of claim 1, characterized in that the mirror assembly constitutes an interior rearview mirror mounted in the center of a vehicle.

20. The dimming mirror assembly of claim 1, characterized in that the mirror assembly constitutes an exterior rear view mirror mounted in the center of a vehicle.

21. The dimming mirror assembly of claim 20, characterized in that the voltage regulating mechanism is coupled to a darkening switch of an interior mirror to substantially darken the rearview mirror mounted on the exterior side due to the darkening of the interior mirror.

22. The dimming mirror assembly of claim 1, characterized in that the housing has a perimeter surface for mounting the housing on a mirror glass.

23. The dimming mirror assembly of claim 1, characterized in that the other portion of the deformable member is fixedly attached to the surface within the housing.

24. The dimming mirror assembly of claim 1, characterized in that a portion of the deformable member is fixedly attached to the reflective member. DIMMING MIRROR ASSEMBLY SUMMARY OF THE INVENTION A dimming mirror assembly (10) has a housing, a reflective member (20), a transparent member (28), a light reducing member (36), and a drive mechanism for introducing and evacuating the light reducing means (36) placed in a gap between the transparent member (28) and the reflective member (20). The reflective member (20) and the transparent member (28) are carried by the housing. At least one of the transparent member (28) and the reflective member (20) can move relative to each other. The amount of light transmitted and reflected from the reflective member (20) is a function of the volume of the light-reducing medium (36) between them, the volume that is variable upon effecting the relative movement between the reflective members. (20) and the transparent member (28). The control mechanism may include a drive mechanism for effecting relative movement between the reflective member (20) and the transparent member (28).