CA1113063A - Illuminated indicator gauge - Google Patents
Illuminated indicator gaugeInfo
- Publication number
- CA1113063A CA1113063A CA317,849A CA317849A CA1113063A CA 1113063 A CA1113063 A CA 1113063A CA 317849 A CA317849 A CA 317849A CA 1113063 A CA1113063 A CA 1113063A
- Authority
- CA
- Canada
- Prior art keywords
- dial plate
- light
- indicator gauge
- set forth
- illuminated indicator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2817—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using reflective elements to split or combine optical signals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
- G01D11/28—Structurally-combined illuminating devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D13/00—Component parts of indicators for measuring arrangements not specially adapted for a specific variable
- G01D13/22—Pointers, e.g. settable pointer
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Details Of Measuring Devices (AREA)
- Details Of Measuring And Other Instruments (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An illuminated indicator gauge having a dial plate and a pointer each constructed of a transparent or translucent material and formed with a reflecting surface wherein the rays of light emitted from a light source into the dial plate are conducted toward an outer end portion of the pointer after two reflections at the respective reflecting surfaces of the dial plate and the pointer whereby the pointer is caused to light up in the region of its outer end portion which is formed with a matte surface at which the light rays are diffusely reflected, characterized by light condensing means located between the light source and the reflecting surface of the dial plate so that the light rays radi-ated out from the light source toward the reflecting surface of the dial plate are condensed before reaching the reflecting surface.
An illuminated indicator gauge having a dial plate and a pointer each constructed of a transparent or translucent material and formed with a reflecting surface wherein the rays of light emitted from a light source into the dial plate are conducted toward an outer end portion of the pointer after two reflections at the respective reflecting surfaces of the dial plate and the pointer whereby the pointer is caused to light up in the region of its outer end portion which is formed with a matte surface at which the light rays are diffusely reflected, characterized by light condensing means located between the light source and the reflecting surface of the dial plate so that the light rays radi-ated out from the light source toward the reflecting surface of the dial plate are condensed before reaching the reflecting surface.
Description
FIELD OF THE INVENTION
The present invention relates to indicator gauges and, more particularly, to an illuminated indicator gauge to be installed on, for example, an instrument panel of an automotive vehicle.
BACKGROUND OF THE INVENTION
A prior-art illuminated indicator gauge comprises a transparent dial plate having an internal reflecting surface which is arranged in such a manner that the rays of light admitted into the dial plate from a light source ;
located in the vicinity of a perimetric portion of the dial plate are caused to change their directions of travel toward a transparent pointer which is rotatable over the front face of the dial plate in a usual manner. The rays of light thus passed to the pointer from the reflecting ' surface in the dial plate are further reflected at a reflecting surface formed on the pointer and the re-; directed toward a matte surface which is formed on an ~' outer end portion of the pointer. The beams of light -~
which are thus incident on the matte surface of the pointer are diffusely reflected at the matte surface and are scattered in various directions therefrom so that the pointer is caused to light up in the region of the matte surface thereof.
The light source utilized in an illuminated indicator gauge of the type thus arranged i5 usually provided by a lamp of a miniature type which practically constitutes a point source of light. The rays of light 11 emanating from such a light source are radiated over a 1, considerable solid angle within the transparent dial plate so that the beams of light admitted into the dial plate are incident with different angles of incidence on the internal reflecting surface in the dial plate. It therefore follows that the beams incident on the reflect- !
ing surface in the dial plate are reflected with different angles of reflection toward the pointer so that not only the rays of light originally admitted into the dial plate are permitted to enter the pointer in a limited proportion but the ~uantity of light to be incider~t on the reflecting surface of the pointer varies with the rotational posit.ion of the pointer relative to the dial plate. These results t in a low luminaire efficacy available of the indicator gauge and further in inconstancy of the brightness to be obtained of the pointer to be rotated over the dial plate.
The present invention contemplates elimination of these problems encountered in prior-art illuminated indicator gauges of the described type. 3 SUMMARY OF THE INVENTION
i In accordance with the present invention, there is provided an illuminated indicator gauge which comprises
The present invention relates to indicator gauges and, more particularly, to an illuminated indicator gauge to be installed on, for example, an instrument panel of an automotive vehicle.
BACKGROUND OF THE INVENTION
A prior-art illuminated indicator gauge comprises a transparent dial plate having an internal reflecting surface which is arranged in such a manner that the rays of light admitted into the dial plate from a light source ;
located in the vicinity of a perimetric portion of the dial plate are caused to change their directions of travel toward a transparent pointer which is rotatable over the front face of the dial plate in a usual manner. The rays of light thus passed to the pointer from the reflecting ' surface in the dial plate are further reflected at a reflecting surface formed on the pointer and the re-; directed toward a matte surface which is formed on an ~' outer end portion of the pointer. The beams of light -~
which are thus incident on the matte surface of the pointer are diffusely reflected at the matte surface and are scattered in various directions therefrom so that the pointer is caused to light up in the region of the matte surface thereof.
The light source utilized in an illuminated indicator gauge of the type thus arranged i5 usually provided by a lamp of a miniature type which practically constitutes a point source of light. The rays of light 11 emanating from such a light source are radiated over a 1, considerable solid angle within the transparent dial plate so that the beams of light admitted into the dial plate are incident with different angles of incidence on the internal reflecting surface in the dial plate. It therefore follows that the beams incident on the reflect- !
ing surface in the dial plate are reflected with different angles of reflection toward the pointer so that not only the rays of light originally admitted into the dial plate are permitted to enter the pointer in a limited proportion but the ~uantity of light to be incider~t on the reflecting surface of the pointer varies with the rotational posit.ion of the pointer relative to the dial plate. These results t in a low luminaire efficacy available of the indicator gauge and further in inconstancy of the brightness to be obtained of the pointer to be rotated over the dial plate.
The present invention contemplates elimination of these problems encountered in prior-art illuminated indicator gauges of the described type. 3 SUMMARY OF THE INVENTION
i In accordance with the present invention, there is provided an illuminated indicator gauge which comprises
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a light-transmitting dial plate having a front face, a light-transmitting pointer which is rotatable over the front face of the dial plate about an axis sub-stantially normal to the front face of the dial plate and which has an inner end portion coniaining the axis of rotation of the pointer therein and an outer end opposite to the outer end portion, and a light source located in conjunction with the dial plate for emitting rays of light toward a perimetric portion of the dial plate, wherein the dial plate has internally formed therein a reflecting surface which is angled at 45 degrees to the front face of the dial plate and the pointer in turn has a reflecting surfac:e formed in the inner end portion thereof and angled at 45 degrees to the,axis of rotation of the pointer ancl a matte rear surface which is bevelled toward the outer end of the pointer, characterized by light condensing means located between the light source and the reflecting surface in the dial plate for condensing the light rays radiated from the light source toward the reflecting surface in the dial plate. ', The light condensing means of the indicator gauge thus constructed and arranged preferably comprises a light collimating element having a focus located in the region of the light source or, when the light source
a light-transmitting dial plate having a front face, a light-transmitting pointer which is rotatable over the front face of the dial plate about an axis sub-stantially normal to the front face of the dial plate and which has an inner end portion coniaining the axis of rotation of the pointer therein and an outer end opposite to the outer end portion, and a light source located in conjunction with the dial plate for emitting rays of light toward a perimetric portion of the dial plate, wherein the dial plate has internally formed therein a reflecting surface which is angled at 45 degrees to the front face of the dial plate and the pointer in turn has a reflecting surfac:e formed in the inner end portion thereof and angled at 45 degrees to the,axis of rotation of the pointer ancl a matte rear surface which is bevelled toward the outer end of the pointer, characterized by light condensing means located between the light source and the reflecting surface in the dial plate for condensing the light rays radiated from the light source toward the reflecting surface in the dial plate. ', The light condensing means of the indicator gauge thus constructed and arranged preferably comprises a light collimating element having a focus located in the region of the light source or, when the light source
- 3 - :
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constitutes a substantial point source of light, pre-ferably at the light source. Such a collimating element may be constituted by a convex lens located between the light source and the reflecting surface in the dial plate or may be integral with the dial plate. Each of the light-transmitting dial plate and pointer is con-structed of a transparent or translucent material.
~ESCRIPTION OF THE DRAWINGS
The features and advantages of an illuminated indicator gauge provided by the present invention will be more clearly appreoiated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate corresponding or similar members and elements throughout the figures and in which:
Fig. 1 is a cross-sectional view showing a repre-sentative example of an illuminated indicator gauge of the character to which the present invention appertains;
Fig. 2A is a view similar to Fig. 1 but shows a !
preferred embodiment of an illuminated indicator gauge according to the present invention;
Fig. 2B is a plan view showing the arrangement of a light source and a dial plate forming part of the indicator gauge illustrated in Fig. 2A;
Figs. 3, 4 and 5 are cross-sectional views showing . .
~ 3~
other preferred embodiments of the illuminated indicator gauge according to the present invention;
Fig. 6A is a plan view showing the arrangement of a light source and a dial plate forming part of still another preferred embodiment of the illuminated indicator -gauge according to the present invention;
Fig. 6B is a cross-sectional view of the arrangement illustrated in Fig. 6A, Fig. 7A is a view similar to Fig. 6A but shows the arrangement of a light source and a dial plate forming .
part of stili another preferred embodiment of the illumi-nated indicator gauge according to the present invention;
and Fig. 7B is a cross-sectional view of the arrangement illustrated in Fig. 7B. I
DETAILED DESCRIPTION OF THE PRIOR ART
Referring to Fig. 1 of the drawings, a known illumi-nated indicator gauge 10 of the type to which the present invention appertains comprises a generally circular dial plate 12 having a front face provided with suitable scale garduations ~not shown). The dial plate 72 has formed in I
its center portion an axial hole 14 through which a shaft 16 having a center axis substantially normal to the front face of the dial plate 12 axially projects from the front face of the dial plate 12 and is rotatable about the center , .
axis thereof with respect to the dial plate 12. The shaft 16 is securely connected at one end thereof to a pointer 18 having an inner end portion mounted on the leading end portion of the shaft 16 and an outer end S portion opposite to the inner end portion and located with an area coextensive with the front face of the dial plate 12. The pointer 18 is thus rotatable over the graduated front face of the dial plate 12 about an axis aligned with the center axis of-the shaft 16. Though not shown in the drawings, the shaft 16 is connected at the other end thereof to a suitable drive mechanism ; which is adapted to drive the pointer 18 to turn about the axis of rotation thereof through an angle dictated by a signal applled to the drive mechanism. Each of the dial plate 12 and the pointer 18 thus arranged is constructed of a suitable rigid, transparent or trans-lucent material such as for example a transparent plastic. The dial plate 12 is fixedly held in place within a suitable casing (not shown) forming part of 2Q the indicator gauge.
The dial plate 12 has further formed in the center portion thereof an equilateral-prism-shaped recess 20 having a square-shaped open end at the rear end of the dial plate 12 and an oblique lateral plane inclined at - 25 an angle of 45 degrees with respect to the front face of the dial plate 12. The oblique lateral plane thus defining an end of the recess 20 forms a bezel or inclined internal face constituting a flat reflecting surface 22 in the transparent or translucent dial plate S 12. The recess 20 thus formed in the dial plate 12 contains therein a portion of the center axis of the dial plate and is substantially aligned with the above- .
mentioned inner end portion of the pointer 18 so that the reflecting surface 22 in the dial plate 12 is ~:-directed at 45 degrees toward the inner end portion of :~
the pointer 18.
On the other hand, the pointer 18 has formed on the inner end portion thereof a bevelled external face which is inclined at 45 degrees with respect to the front face of the dial plate 12 and which constitutes a flat reflecting surface 24 on the pointer 18. The recess 20 in the dial plate 12 and the bevelled external face of the pointer 18 are dimensioned-so that the -respective reflecting surfaces 22 and 24 of the dial plate 12 and the pointer 12 are always substantially aligned or largely coextensive with each other in a direction parallel with the axis of rotation of the pointer 18 without respect to the rotational position of the pointer 18 over the dial plate 12. The outer end portion of the pointer 18 has a matte rear surface $~
26 which is bevelled in its entirety toward the outer end of the pointer.
A source of light as indicated at 28 is fixedly located in conjunction with the dial plate 12 in such a manner that the rays of light emanating from the light source 28 are incident on the reflecting surface 22 in the dial plate 12 through a perimetric portion 12a of the dial plate 12 and form a beam of light ~1 which travels in a radial direction within the dial plate 12 until the light beam Al reaches the reflecting surface 22. The beam of ligh.t Al thus incident on the reflect-ing surface 22 of the dial plate 12 is reflected at the surface 22 and enters the transparent or translucent pointer 18 in a direction substantially parallel with the axis of rotation of the pointer 18 as indicated at A2 in Fig. 1. The reflected beam of light A2 advances in the pointer 18 and is further reflected at the ; reflecting surface 24 of the pointer 18 toward the outer end portion of the pointer 18 as indicated at A3.
The Iight beam A3 is incident on the bevelled matte rear surface 26 of the outer end portion of the pointer 18 and is diffusely reflected at the matte surface 26.
The light thus scattered in the outer end portion of the pointer 18 illuminates the outer end portion of 25 the pointer 18 and enables the viewer of the indicator ~ h~ 3 : -gauge 10 to visually recognize the scale graduation being indexed by the pointer 18. Indicated by phantom lines in Fig. 1 is a cover plate 30 which may be pro-vided to prevent leakage of light from the region surrounding the dial plate 12 into the viewer's visual field. - I
In the arrangement illustrated in Fig. 1, the flat reflecting surface 22 formed in the dial plate 12 constitutes an oblique lateral surface of a 90-degree prism. If, therefore, collimated rays of light are incident on the reflecting surface 22 at 45 degrees to the reflecting surface, the light rays reflected from the reflecting surface 22 of the dial plate 12 will be permitted to be totally incident on the reflecting surface 24 of the pointer 18. Since, however, the lamps used as the sources of light in indicator gauges of the described character are usually of the miniature type, the light source 28 provided in the indicator gauge 10 virtually constitutes a point source producing ; ~ -rays of light which are radiated over a considerable solid angle within the dial plate 12. Thus, the light rays emitted from the source 28 and entering the dial ;
plate 12 include beams of light Bl and Cl which are incident upon the reflecting surface 22 of the dial plate 12 at angles which are similar than 45 degrees as -in the case of the light beam Bl or larger than 45 ,:
degrees as in the case of the light beam Cl. When the light beams incident on the reflecting surface 22 of the dial plate 12 at angles smaller or larger than 45 degrees are reflected from the reflecting surface 22, .
some of the reflected light beams are not permitted to enter the pointer 18 as in the case of the reflected light beam B2 resulting from the initial light beam Bl and some are enabled to enter the pointer 18 but are not permittèd to proceed into the inner end portion of the pointer 18 as in the case of the reflected light beam :
C2 resulting from the initial light beam Cl. Furthermore, there will be such light beams that are permitted to be incident upon the reflecting surface 24 of the pointer but which are not reflected from the reflecting surface 24 toward the bevelled matte rear surface 26 of the outer end portion of the pointer 18. Thus, only a :
limited portion of the light originally emitted from the light source 28 and admitted into the dial plate 12 is permitted to finally reach the bevelled matte rear surface 26 of the pointer 18 after two reflections :
in the dial plate 12 and the pointer 18. This results in a low luminaire efficacy available of the indicator gauge 10. Because, furthermore, of the fact that the angles of incidence and accordingly the angles of -10- ~
!
reflection at the reflecting surface 22 in the dial plate 12 thus vary depending upon the locations at which the rays of light are incident on the reflecting surface 22, the quantity of the light which is permitted to proceed from the reflecting surface 22 into the inner end portion of the pointer 18 var.ies with the angular position of the pointer 18 with respect to the :
dial plate 12 so that the degree of brightness obtained in the region of the outer end portion of the pointer 18 varies as the pointer 18 is rotated over the front face of the dial plate 12 about the axis of rotation .
of the pointer. The present invention contemplates :
resolution of these problems which have been inherent .
in known illuminated indicator gauges of the type thus far been described with reference to Fig. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figs~ 2A and 2B of the drawings, an illuminated indicator gauge embodying the present invention as designated in its entirety by 10a is shown comprising, in addition to a transparent or translucent dial plate 12 and a transparent or translucent pointer 18 which are arranged similarly to their respective counterparts in the prior-art indicator gauge 10 shown in Fig. 1, a thin, colored coating 32 applied to the total area of the front face of the dial plate 12 and a thin, opaque coating 34 applied to the outer surface of the colored coating 32 as illustrated in Fig. 2A.
The opaque coating 34 is transparent or void at 36 in the form of scale graduations and over its central area 36' substantially registering with the reflecting sur-face 22 in the dial plate 12. The coatings 32 and 34 may be applied to the dial plate 12 by printing. The dial plate 12 further has light reflective coatings 38 and 38' applied to the rear and outer peripheral sur-faces, respectively, of the dial plate for aiding in the illumination of the scale graduations 36 in the opaque coating 34 when the dial plate 12 is irradiated with the light emanating from the light source 28.
In the embodiment illustrated in Figs. 2A and 2B, there is provided a convex lens 40 located between the light source 28 and the perimetric portion l~a of the dial plate 12 in such a manner that the lens 40 has one of its foci at the light source 28 which is herein assumed to constitute a substantial point source as previously noted. The light radiating out from the light source 28 is thus collimated by the convex lens 40 and the beams of light issuing from the lens 40 enter the dial plate 12 through the above-mentioned perimetric portion 12a of the dial plate in directions substantially parallel with the front face of the dial plate 12 as indicated by D1 in Fig. 2A. All the beams of light Dl admitted into the dial plate 12 are inherent with the angles of about 45 degrees on the reflecting surface 22 in the dial plate 22 and are re-directed to advance away from the reflecting surface 22 in direc-tions substantially parallel with the axis of rotation of the pointer 18 as indicated by D2 in Fig. 2A. The beams of light ~2 entering the inner end portion of the pointer 18 are incident with the angles of 45 degrees on the reflecting surface 24 of the pointer 18 and are further re-directed toward the outer end portion of the pointer 18 in directions substantially parallel with the front face of the:dial plate 12 as indicated by D3 in Fig. 2~. The beams of light D3 thus travelling in the pointer 18 reach the matte rear surface 26 of the pointer and are diffusely reflected at the surface 26 for being scattered in various directions in the pointer 18 and thereby lighting up the pointer l8 in the region of the matte rear surface 26 thereof.
The convex lens 40 provided as light-condensing means in the embodiment of Figs. 2A and 2B functions as a collimating element effective to collimate the rays of light radiated from the light source 28 and to direct the collimated rays of light on to the reflect-ing surface 22 in the dial plate 12. The rays of light admitted into the dial plate 12 are therefore incident , with substantially equal angles on the reflecting -surface 22 in the dial plate 12 so that the light rays re-directed after reflection at the reflecting surface 22 are allowed to uniformly proceed into the inner end portion of the polnter 18 with substantially equal angles of incidence. For this reason, not only an increased degree of brightness is obtained in the reyion of the matte rear surface 26 of the pointer 18 but the degree of brightness remains substantially constant when the pointer 18 is turned about the axis of rotation thereof with respect to the dial plate 12.
The convex lens 40 provided in the embodiment of Figs.
2A and 2B is assumed to be a bi-convex or convexo-convex lens by way of example but, if desired, may be replaced with a plano-convex or positive meniscus lens (not shown). In the embodiment of Figs. 2A and 2B, furthermore, the perimetric portion 12a of the dial plate 12 is assumed to have a substantially flat end face which is substantially perpendicular to the center axis of the convex lens 40 as shown in Fig. 2B so that the collimated rays of light issuing from the lens 40 are precluded from being refracted at the end face of the portion 12a when entering the dial plate 12.
Fig~ 3 shows an embodiment in which a collimating element provided as light-condensing means between the light source 28 and the reflecting surface 22 in the dial plate 12 is constituted by a convex lens formed as an integral portion of the transparent or translucent dial plate 12. The perimetric portion 12a of the dial plate 12 in the embodiment shown in Fig. 3 is formed with a projection 42 having an outer face spherically protruding toward the light source 28. The outer face of the projection 42 thus formed of the perimetric portion 12a of the dial plate 12 is arcuately curved --~
in cross-section with a radius of curvature which is selected to provide a focus located at the light source 28 so that the rays of light radiated out from the light source 28 are substantially collimated into beams of substantially parallel light in the dial plate 12.
The collimated beams of light thus produced in the dial plate 12 are incident with angles of 45 degrees on the reflecting surface 22 in the dial plate 12 and provide substantially the same effects as those achieved in the embodiment of Figs. 2A and 2B.
While the collimating element provided in the embodiment illustrated in Fig. 3 is located at a peri-metric end of the dial plate 12, a collimating element integral with the dial plate 12 may be formed internally of the dial plate and located between the perimetric portion 1-2a and the reflecting surface 22 of the dial plate. Figs. 4 and 5 show embodiments each incorporating .
such a collimating element.
In the embodiment illustrated in Fig. 4, the dial plate 12 having the reflecting surface 22 is formed with an opening 44 which is open at the front and rear ends of the dial plate 12 and which is defined between a substantially flat internal surface 44a located between the perimetric portion 12a and the reflecting surface 22 of the dial plate 12 and an internal projection 44b located between the flat internal surface 44a and the reflecting surface 22 in the dial plate 12 and spheri-cally protruding away from the reflecting surface 22 toward the flat internal surface 44a and accordingly toward the light source 28 across the internal surface 44a and the perimetric portion 12a of the dial plate 12. The flat internal surface 44a provided be~ween the perimetric portion 12 and the internal projection 44b of the dial plate 12 is assumed, by way of example, to be substantially perpendicular to the center axis of the internal projection 44b or to a line passing through the light source 28 and the internal projection 44b in the dial plate 12.
The internal projection 44b thus formed in the dial plate 12 has a surface which is arcuately curved in cross-section with a radius of curvature which is selected to provide a focus located at the light source f . - 16 -28. The rays of light emanating from the light source 28 and admitted into the dial plate 12 through the perimetric po.rtion 12a of the dial plate 12 travel with a certain solid angle within the dial plate 12 as indicated by El until the beams of light El reach the internal projection 44b in the dial plate 12. The beams of light El are collimated at the spherically protruding surface of the internal projection 44_ in the dial plate 12 and the resultant beams of parallel light, indicated by E2, are incident on the reflecting surface 22 in the dial plate 12 with the angles of incidence of about 45 degrees.
The collimating element provided in the embodiment of Fig. 5 is essentially similar in effect to the collimating element constituted by the internal pro-jection 44b in the embodiment of Fig. 4 and is formed in the dial plate 12 having an opening 46 which is open at the front and rear ends of the dial plate 12. The --opening 46 is defined between a substantially flat internal surface 46a located between the perimetric portion 12a and the reflecting surface 22 of the dial plate 12 and an internal projection 46b located between .
the flat internal surface 46a and the perimetric portion 12a.of the dial plate 12 and spherically protruding away from the perimetric portion 12a toward the flat internal - 17 - .
surface 46a and accordingly toward the reflecting surface 22 in the dial plate 12 across the flat internal surface 46a. The flat internal surface 46a provided between the internal projection 46b and the reflecting surface 22 of the dial plate 12 is assumed, by way of example, to be substantially perpendicular to the center axis of the internal projection 46b or to a line passing through the light source 28 and the internal projection 46b in the dial plate 12. The internal projection 46b thus formed in the dial plate 12 has a surface which is arcuately curved in cross-section with a radius of curvature which is selected to provide a focus located at the light source 28~ The rays of Light radiated out from the light source 28 and admitted into the dial plate 12 through the perimetric portion 12a of the dial plate 12 travel with a certain solid angle within the dial plate 12 as indicated by Fl until the beams of light Fl reach the spherically protruding surface of the internal projection 46b in the dial plate 12. The beams of light issuing from the internal projection 46b are collimated into beams of substantially parallel light F2, which are incident with the angles of about 45 degrees on the reflecting surface 22 in the dial plate 12.
In each of the embodiments illustrated in Figs. 4 1~ -and 5, the perimetric portion 12a of the dial plate 12 is assumed to have a substantially flat end face which is substantially perpendicular to the center axis of the internal projection 44b or 46b in the dial plate 12 .
or to a line passing through the internal projection 44b or 46b and the light source 28 which is assumed to practically constitute a point source of light.
If the perimetric portion 12a of the dial plate 12 has its end face arcuately curved-about an axis which is coincident or otherwise substantially parallel with the center axis of the dial plate 12 as shown in Fig. 6A, the particular portion 12a of the dial plate 12 is operable per se as light condensing means without having recourse to the provision of any additional collimating element between the light source 28 ancl the reflectincJ
surface 22 in the dial plate 12. If, in this instance, the radius of curvature of the arcuately curved end face of the perimetric portion 12a of the dial plate 12 is selected so that the perimetric portion 12a consti- -tutes a cylindrical convex lens having a focal axis located at the light source 28, the rays of light proceeding from the light source 28 into the dial plate 12 through the perimetric portion 12a are substantially collimated in planes parallel with the front face of the dial plate 12 or perpendicular to the axis of curvature of the perimetric portion 12a as indicated by G in Fig. 6A, although the beams of light admitted into the dial plate 12 are left to radiate within the dial plate in planes normal to the front face of the dial plate 12 as indicated by G' in Fig. 6B until the beams of light G' are incident on the reflecting surface 22 in the dial plate 12.
Figs. 7A and 7B show an embodiment in which the perimetric portion 12a of the dial plate 12 is configured in such a manner as to constitute a cylindrical convex lens which is integral with the dial plate 12 as in the arrangement illustrated in Figs. 6A and 6B but which has an axis substantially parallel with the front face of the dial plate 12. Thus, the perimetric portion 12a of the dial plate 12 in the embodiment of Figs. 7A and 7B
has an end face which is elongated a suitable length substantially perpendicularly to a line passing through the light source 28 and the reflecting surface 22 or more exactly the center axis of the dial plate and which arcuately protrudes in cross-section toward the light source 28 with a radius of curvature which is such that the cylindrical convex lens constituted by the perimetric portion 12a of the dial plate 12 has a focal axis which passes through the light source 28.
The rays of light proceeding from the light source 28 into the dial plate 12 through the perimetric portion 12a of the dial plate are therefore left to radiate within the dial plate 12 in planes parallel with the front face of the dial plate 12 as indicated by H in Fig. 7B but are substantially collimated in planes normal to the front face of the dial plate 12 as indicated by H' in Fig. 7A.
It has been assumed that the light source 28 in each of the embodiments hereinbefore described is positioned fixedly with respect to the dial plate 12 so that the focal point or axis of the collimating element or the lens portion of the dial plate 12 is determined depending upon the position of the light source 28 relative to the dial plate 12 but the focal point or axis of the collimating element or the lens portion provided in each embodiment may be determined arbitrarily if there is an allowance for selecting the position of the light source 28 with respect to the dial plate 12 which is assumed to be held stationary.
While, furthermore, it has also been assumed that the focal point or axis of the collimating element or the lens portion of the dial plate 12 in each of the embodiments described is located at the light source 28 which is assumed to practically constitute a point source of light or, conversely, that the light source . ' : ,: -~l' 28 as the point source is located at the focal point or axis, such an arrangement is not of critical importance in sarrying out the present invention and, thus, the focal point or axis of the collimating element or the lens portion of the dial plate 12 in each of the embodiments described may be located slightly off the light source 28 or, conversely, the light source 28 may be located slightly off the focal point or axis of the collimating element or the lens portion of the dial plate 12. ~.~here the collimating element is constituted by the lens portion of the dial plate 12 as in each of the embodiments described with reference to Figs. 3 to 7s, the collimating element need not be configured in such a manner as to have a focal point or axis at a definite point or axis insofar as the radiant beams of light incident on the colli-mating element can be concentrated or condensed to a satisfactory extent after the beams of light are passed through the collimating element.
Althoughr furthermore, it has been assumed that the dial plate 12 has a center axis and that the axis of rotation of the pointer 18 rotatable over the front face of the dial plate 12 is substantially in aline with the center axis of the dial plate 12 as in an ordinary speedometer installed on the instrument panel of an ~
.
automotive vehicle, the present invention is applicable to an indicator gauge of the type in which the dial plate has no definite center axis therethrough or in which the dial plate has a definite center axis there-through but the axis of rotation of the pointer rotatablewith respect to the dial plate is offset from the center axis of the dial plate as in a voltmeter, an oil gauge, a fuel gauge or a temperature gauge for, for example, I
automotive use. `
i .
I' ..
constitutes a substantial point source of light, pre-ferably at the light source. Such a collimating element may be constituted by a convex lens located between the light source and the reflecting surface in the dial plate or may be integral with the dial plate. Each of the light-transmitting dial plate and pointer is con-structed of a transparent or translucent material.
~ESCRIPTION OF THE DRAWINGS
The features and advantages of an illuminated indicator gauge provided by the present invention will be more clearly appreoiated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate corresponding or similar members and elements throughout the figures and in which:
Fig. 1 is a cross-sectional view showing a repre-sentative example of an illuminated indicator gauge of the character to which the present invention appertains;
Fig. 2A is a view similar to Fig. 1 but shows a !
preferred embodiment of an illuminated indicator gauge according to the present invention;
Fig. 2B is a plan view showing the arrangement of a light source and a dial plate forming part of the indicator gauge illustrated in Fig. 2A;
Figs. 3, 4 and 5 are cross-sectional views showing . .
~ 3~
other preferred embodiments of the illuminated indicator gauge according to the present invention;
Fig. 6A is a plan view showing the arrangement of a light source and a dial plate forming part of still another preferred embodiment of the illuminated indicator -gauge according to the present invention;
Fig. 6B is a cross-sectional view of the arrangement illustrated in Fig. 6A, Fig. 7A is a view similar to Fig. 6A but shows the arrangement of a light source and a dial plate forming .
part of stili another preferred embodiment of the illumi-nated indicator gauge according to the present invention;
and Fig. 7B is a cross-sectional view of the arrangement illustrated in Fig. 7B. I
DETAILED DESCRIPTION OF THE PRIOR ART
Referring to Fig. 1 of the drawings, a known illumi-nated indicator gauge 10 of the type to which the present invention appertains comprises a generally circular dial plate 12 having a front face provided with suitable scale garduations ~not shown). The dial plate 72 has formed in I
its center portion an axial hole 14 through which a shaft 16 having a center axis substantially normal to the front face of the dial plate 12 axially projects from the front face of the dial plate 12 and is rotatable about the center , .
axis thereof with respect to the dial plate 12. The shaft 16 is securely connected at one end thereof to a pointer 18 having an inner end portion mounted on the leading end portion of the shaft 16 and an outer end S portion opposite to the inner end portion and located with an area coextensive with the front face of the dial plate 12. The pointer 18 is thus rotatable over the graduated front face of the dial plate 12 about an axis aligned with the center axis of-the shaft 16. Though not shown in the drawings, the shaft 16 is connected at the other end thereof to a suitable drive mechanism ; which is adapted to drive the pointer 18 to turn about the axis of rotation thereof through an angle dictated by a signal applled to the drive mechanism. Each of the dial plate 12 and the pointer 18 thus arranged is constructed of a suitable rigid, transparent or trans-lucent material such as for example a transparent plastic. The dial plate 12 is fixedly held in place within a suitable casing (not shown) forming part of 2Q the indicator gauge.
The dial plate 12 has further formed in the center portion thereof an equilateral-prism-shaped recess 20 having a square-shaped open end at the rear end of the dial plate 12 and an oblique lateral plane inclined at - 25 an angle of 45 degrees with respect to the front face of the dial plate 12. The oblique lateral plane thus defining an end of the recess 20 forms a bezel or inclined internal face constituting a flat reflecting surface 22 in the transparent or translucent dial plate S 12. The recess 20 thus formed in the dial plate 12 contains therein a portion of the center axis of the dial plate and is substantially aligned with the above- .
mentioned inner end portion of the pointer 18 so that the reflecting surface 22 in the dial plate 12 is ~:-directed at 45 degrees toward the inner end portion of :~
the pointer 18.
On the other hand, the pointer 18 has formed on the inner end portion thereof a bevelled external face which is inclined at 45 degrees with respect to the front face of the dial plate 12 and which constitutes a flat reflecting surface 24 on the pointer 18. The recess 20 in the dial plate 12 and the bevelled external face of the pointer 18 are dimensioned-so that the -respective reflecting surfaces 22 and 24 of the dial plate 12 and the pointer 12 are always substantially aligned or largely coextensive with each other in a direction parallel with the axis of rotation of the pointer 18 without respect to the rotational position of the pointer 18 over the dial plate 12. The outer end portion of the pointer 18 has a matte rear surface $~
26 which is bevelled in its entirety toward the outer end of the pointer.
A source of light as indicated at 28 is fixedly located in conjunction with the dial plate 12 in such a manner that the rays of light emanating from the light source 28 are incident on the reflecting surface 22 in the dial plate 12 through a perimetric portion 12a of the dial plate 12 and form a beam of light ~1 which travels in a radial direction within the dial plate 12 until the light beam Al reaches the reflecting surface 22. The beam of ligh.t Al thus incident on the reflect-ing surface 22 of the dial plate 12 is reflected at the surface 22 and enters the transparent or translucent pointer 18 in a direction substantially parallel with the axis of rotation of the pointer 18 as indicated at A2 in Fig. 1. The reflected beam of light A2 advances in the pointer 18 and is further reflected at the ; reflecting surface 24 of the pointer 18 toward the outer end portion of the pointer 18 as indicated at A3.
The Iight beam A3 is incident on the bevelled matte rear surface 26 of the outer end portion of the pointer 18 and is diffusely reflected at the matte surface 26.
The light thus scattered in the outer end portion of the pointer 18 illuminates the outer end portion of 25 the pointer 18 and enables the viewer of the indicator ~ h~ 3 : -gauge 10 to visually recognize the scale graduation being indexed by the pointer 18. Indicated by phantom lines in Fig. 1 is a cover plate 30 which may be pro-vided to prevent leakage of light from the region surrounding the dial plate 12 into the viewer's visual field. - I
In the arrangement illustrated in Fig. 1, the flat reflecting surface 22 formed in the dial plate 12 constitutes an oblique lateral surface of a 90-degree prism. If, therefore, collimated rays of light are incident on the reflecting surface 22 at 45 degrees to the reflecting surface, the light rays reflected from the reflecting surface 22 of the dial plate 12 will be permitted to be totally incident on the reflecting surface 24 of the pointer 18. Since, however, the lamps used as the sources of light in indicator gauges of the described character are usually of the miniature type, the light source 28 provided in the indicator gauge 10 virtually constitutes a point source producing ; ~ -rays of light which are radiated over a considerable solid angle within the dial plate 12. Thus, the light rays emitted from the source 28 and entering the dial ;
plate 12 include beams of light Bl and Cl which are incident upon the reflecting surface 22 of the dial plate 12 at angles which are similar than 45 degrees as -in the case of the light beam Bl or larger than 45 ,:
degrees as in the case of the light beam Cl. When the light beams incident on the reflecting surface 22 of the dial plate 12 at angles smaller or larger than 45 degrees are reflected from the reflecting surface 22, .
some of the reflected light beams are not permitted to enter the pointer 18 as in the case of the reflected light beam B2 resulting from the initial light beam Bl and some are enabled to enter the pointer 18 but are not permittèd to proceed into the inner end portion of the pointer 18 as in the case of the reflected light beam :
C2 resulting from the initial light beam Cl. Furthermore, there will be such light beams that are permitted to be incident upon the reflecting surface 24 of the pointer but which are not reflected from the reflecting surface 24 toward the bevelled matte rear surface 26 of the outer end portion of the pointer 18. Thus, only a :
limited portion of the light originally emitted from the light source 28 and admitted into the dial plate 12 is permitted to finally reach the bevelled matte rear surface 26 of the pointer 18 after two reflections :
in the dial plate 12 and the pointer 18. This results in a low luminaire efficacy available of the indicator gauge 10. Because, furthermore, of the fact that the angles of incidence and accordingly the angles of -10- ~
!
reflection at the reflecting surface 22 in the dial plate 12 thus vary depending upon the locations at which the rays of light are incident on the reflecting surface 22, the quantity of the light which is permitted to proceed from the reflecting surface 22 into the inner end portion of the pointer 18 var.ies with the angular position of the pointer 18 with respect to the :
dial plate 12 so that the degree of brightness obtained in the region of the outer end portion of the pointer 18 varies as the pointer 18 is rotated over the front face of the dial plate 12 about the axis of rotation .
of the pointer. The present invention contemplates :
resolution of these problems which have been inherent .
in known illuminated indicator gauges of the type thus far been described with reference to Fig. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figs~ 2A and 2B of the drawings, an illuminated indicator gauge embodying the present invention as designated in its entirety by 10a is shown comprising, in addition to a transparent or translucent dial plate 12 and a transparent or translucent pointer 18 which are arranged similarly to their respective counterparts in the prior-art indicator gauge 10 shown in Fig. 1, a thin, colored coating 32 applied to the total area of the front face of the dial plate 12 and a thin, opaque coating 34 applied to the outer surface of the colored coating 32 as illustrated in Fig. 2A.
The opaque coating 34 is transparent or void at 36 in the form of scale graduations and over its central area 36' substantially registering with the reflecting sur-face 22 in the dial plate 12. The coatings 32 and 34 may be applied to the dial plate 12 by printing. The dial plate 12 further has light reflective coatings 38 and 38' applied to the rear and outer peripheral sur-faces, respectively, of the dial plate for aiding in the illumination of the scale graduations 36 in the opaque coating 34 when the dial plate 12 is irradiated with the light emanating from the light source 28.
In the embodiment illustrated in Figs. 2A and 2B, there is provided a convex lens 40 located between the light source 28 and the perimetric portion l~a of the dial plate 12 in such a manner that the lens 40 has one of its foci at the light source 28 which is herein assumed to constitute a substantial point source as previously noted. The light radiating out from the light source 28 is thus collimated by the convex lens 40 and the beams of light issuing from the lens 40 enter the dial plate 12 through the above-mentioned perimetric portion 12a of the dial plate in directions substantially parallel with the front face of the dial plate 12 as indicated by D1 in Fig. 2A. All the beams of light Dl admitted into the dial plate 12 are inherent with the angles of about 45 degrees on the reflecting surface 22 in the dial plate 22 and are re-directed to advance away from the reflecting surface 22 in direc-tions substantially parallel with the axis of rotation of the pointer 18 as indicated by D2 in Fig. 2A. The beams of light ~2 entering the inner end portion of the pointer 18 are incident with the angles of 45 degrees on the reflecting surface 24 of the pointer 18 and are further re-directed toward the outer end portion of the pointer 18 in directions substantially parallel with the front face of the:dial plate 12 as indicated by D3 in Fig. 2~. The beams of light D3 thus travelling in the pointer 18 reach the matte rear surface 26 of the pointer and are diffusely reflected at the surface 26 for being scattered in various directions in the pointer 18 and thereby lighting up the pointer l8 in the region of the matte rear surface 26 thereof.
The convex lens 40 provided as light-condensing means in the embodiment of Figs. 2A and 2B functions as a collimating element effective to collimate the rays of light radiated from the light source 28 and to direct the collimated rays of light on to the reflect-ing surface 22 in the dial plate 12. The rays of light admitted into the dial plate 12 are therefore incident , with substantially equal angles on the reflecting -surface 22 in the dial plate 12 so that the light rays re-directed after reflection at the reflecting surface 22 are allowed to uniformly proceed into the inner end portion of the polnter 18 with substantially equal angles of incidence. For this reason, not only an increased degree of brightness is obtained in the reyion of the matte rear surface 26 of the pointer 18 but the degree of brightness remains substantially constant when the pointer 18 is turned about the axis of rotation thereof with respect to the dial plate 12.
The convex lens 40 provided in the embodiment of Figs.
2A and 2B is assumed to be a bi-convex or convexo-convex lens by way of example but, if desired, may be replaced with a plano-convex or positive meniscus lens (not shown). In the embodiment of Figs. 2A and 2B, furthermore, the perimetric portion 12a of the dial plate 12 is assumed to have a substantially flat end face which is substantially perpendicular to the center axis of the convex lens 40 as shown in Fig. 2B so that the collimated rays of light issuing from the lens 40 are precluded from being refracted at the end face of the portion 12a when entering the dial plate 12.
Fig~ 3 shows an embodiment in which a collimating element provided as light-condensing means between the light source 28 and the reflecting surface 22 in the dial plate 12 is constituted by a convex lens formed as an integral portion of the transparent or translucent dial plate 12. The perimetric portion 12a of the dial plate 12 in the embodiment shown in Fig. 3 is formed with a projection 42 having an outer face spherically protruding toward the light source 28. The outer face of the projection 42 thus formed of the perimetric portion 12a of the dial plate 12 is arcuately curved --~
in cross-section with a radius of curvature which is selected to provide a focus located at the light source 28 so that the rays of light radiated out from the light source 28 are substantially collimated into beams of substantially parallel light in the dial plate 12.
The collimated beams of light thus produced in the dial plate 12 are incident with angles of 45 degrees on the reflecting surface 22 in the dial plate 12 and provide substantially the same effects as those achieved in the embodiment of Figs. 2A and 2B.
While the collimating element provided in the embodiment illustrated in Fig. 3 is located at a peri-metric end of the dial plate 12, a collimating element integral with the dial plate 12 may be formed internally of the dial plate and located between the perimetric portion 1-2a and the reflecting surface 22 of the dial plate. Figs. 4 and 5 show embodiments each incorporating .
such a collimating element.
In the embodiment illustrated in Fig. 4, the dial plate 12 having the reflecting surface 22 is formed with an opening 44 which is open at the front and rear ends of the dial plate 12 and which is defined between a substantially flat internal surface 44a located between the perimetric portion 12a and the reflecting surface 22 of the dial plate 12 and an internal projection 44b located between the flat internal surface 44a and the reflecting surface 22 in the dial plate 12 and spheri-cally protruding away from the reflecting surface 22 toward the flat internal surface 44a and accordingly toward the light source 28 across the internal surface 44a and the perimetric portion 12a of the dial plate 12. The flat internal surface 44a provided be~ween the perimetric portion 12 and the internal projection 44b of the dial plate 12 is assumed, by way of example, to be substantially perpendicular to the center axis of the internal projection 44b or to a line passing through the light source 28 and the internal projection 44b in the dial plate 12.
The internal projection 44b thus formed in the dial plate 12 has a surface which is arcuately curved in cross-section with a radius of curvature which is selected to provide a focus located at the light source f . - 16 -28. The rays of light emanating from the light source 28 and admitted into the dial plate 12 through the perimetric po.rtion 12a of the dial plate 12 travel with a certain solid angle within the dial plate 12 as indicated by El until the beams of light El reach the internal projection 44b in the dial plate 12. The beams of light El are collimated at the spherically protruding surface of the internal projection 44_ in the dial plate 12 and the resultant beams of parallel light, indicated by E2, are incident on the reflecting surface 22 in the dial plate 12 with the angles of incidence of about 45 degrees.
The collimating element provided in the embodiment of Fig. 5 is essentially similar in effect to the collimating element constituted by the internal pro-jection 44b in the embodiment of Fig. 4 and is formed in the dial plate 12 having an opening 46 which is open at the front and rear ends of the dial plate 12. The --opening 46 is defined between a substantially flat internal surface 46a located between the perimetric portion 12a and the reflecting surface 22 of the dial plate 12 and an internal projection 46b located between .
the flat internal surface 46a and the perimetric portion 12a.of the dial plate 12 and spherically protruding away from the perimetric portion 12a toward the flat internal - 17 - .
surface 46a and accordingly toward the reflecting surface 22 in the dial plate 12 across the flat internal surface 46a. The flat internal surface 46a provided between the internal projection 46b and the reflecting surface 22 of the dial plate 12 is assumed, by way of example, to be substantially perpendicular to the center axis of the internal projection 46b or to a line passing through the light source 28 and the internal projection 46b in the dial plate 12. The internal projection 46b thus formed in the dial plate 12 has a surface which is arcuately curved in cross-section with a radius of curvature which is selected to provide a focus located at the light source 28~ The rays of Light radiated out from the light source 28 and admitted into the dial plate 12 through the perimetric portion 12a of the dial plate 12 travel with a certain solid angle within the dial plate 12 as indicated by Fl until the beams of light Fl reach the spherically protruding surface of the internal projection 46b in the dial plate 12. The beams of light issuing from the internal projection 46b are collimated into beams of substantially parallel light F2, which are incident with the angles of about 45 degrees on the reflecting surface 22 in the dial plate 12.
In each of the embodiments illustrated in Figs. 4 1~ -and 5, the perimetric portion 12a of the dial plate 12 is assumed to have a substantially flat end face which is substantially perpendicular to the center axis of the internal projection 44b or 46b in the dial plate 12 .
or to a line passing through the internal projection 44b or 46b and the light source 28 which is assumed to practically constitute a point source of light.
If the perimetric portion 12a of the dial plate 12 has its end face arcuately curved-about an axis which is coincident or otherwise substantially parallel with the center axis of the dial plate 12 as shown in Fig. 6A, the particular portion 12a of the dial plate 12 is operable per se as light condensing means without having recourse to the provision of any additional collimating element between the light source 28 ancl the reflectincJ
surface 22 in the dial plate 12. If, in this instance, the radius of curvature of the arcuately curved end face of the perimetric portion 12a of the dial plate 12 is selected so that the perimetric portion 12a consti- -tutes a cylindrical convex lens having a focal axis located at the light source 28, the rays of light proceeding from the light source 28 into the dial plate 12 through the perimetric portion 12a are substantially collimated in planes parallel with the front face of the dial plate 12 or perpendicular to the axis of curvature of the perimetric portion 12a as indicated by G in Fig. 6A, although the beams of light admitted into the dial plate 12 are left to radiate within the dial plate in planes normal to the front face of the dial plate 12 as indicated by G' in Fig. 6B until the beams of light G' are incident on the reflecting surface 22 in the dial plate 12.
Figs. 7A and 7B show an embodiment in which the perimetric portion 12a of the dial plate 12 is configured in such a manner as to constitute a cylindrical convex lens which is integral with the dial plate 12 as in the arrangement illustrated in Figs. 6A and 6B but which has an axis substantially parallel with the front face of the dial plate 12. Thus, the perimetric portion 12a of the dial plate 12 in the embodiment of Figs. 7A and 7B
has an end face which is elongated a suitable length substantially perpendicularly to a line passing through the light source 28 and the reflecting surface 22 or more exactly the center axis of the dial plate and which arcuately protrudes in cross-section toward the light source 28 with a radius of curvature which is such that the cylindrical convex lens constituted by the perimetric portion 12a of the dial plate 12 has a focal axis which passes through the light source 28.
The rays of light proceeding from the light source 28 into the dial plate 12 through the perimetric portion 12a of the dial plate are therefore left to radiate within the dial plate 12 in planes parallel with the front face of the dial plate 12 as indicated by H in Fig. 7B but are substantially collimated in planes normal to the front face of the dial plate 12 as indicated by H' in Fig. 7A.
It has been assumed that the light source 28 in each of the embodiments hereinbefore described is positioned fixedly with respect to the dial plate 12 so that the focal point or axis of the collimating element or the lens portion of the dial plate 12 is determined depending upon the position of the light source 28 relative to the dial plate 12 but the focal point or axis of the collimating element or the lens portion provided in each embodiment may be determined arbitrarily if there is an allowance for selecting the position of the light source 28 with respect to the dial plate 12 which is assumed to be held stationary.
While, furthermore, it has also been assumed that the focal point or axis of the collimating element or the lens portion of the dial plate 12 in each of the embodiments described is located at the light source 28 which is assumed to practically constitute a point source of light or, conversely, that the light source . ' : ,: -~l' 28 as the point source is located at the focal point or axis, such an arrangement is not of critical importance in sarrying out the present invention and, thus, the focal point or axis of the collimating element or the lens portion of the dial plate 12 in each of the embodiments described may be located slightly off the light source 28 or, conversely, the light source 28 may be located slightly off the focal point or axis of the collimating element or the lens portion of the dial plate 12. ~.~here the collimating element is constituted by the lens portion of the dial plate 12 as in each of the embodiments described with reference to Figs. 3 to 7s, the collimating element need not be configured in such a manner as to have a focal point or axis at a definite point or axis insofar as the radiant beams of light incident on the colli-mating element can be concentrated or condensed to a satisfactory extent after the beams of light are passed through the collimating element.
Althoughr furthermore, it has been assumed that the dial plate 12 has a center axis and that the axis of rotation of the pointer 18 rotatable over the front face of the dial plate 12 is substantially in aline with the center axis of the dial plate 12 as in an ordinary speedometer installed on the instrument panel of an ~
.
automotive vehicle, the present invention is applicable to an indicator gauge of the type in which the dial plate has no definite center axis therethrough or in which the dial plate has a definite center axis there-through but the axis of rotation of the pointer rotatablewith respect to the dial plate is offset from the center axis of the dial plate as in a voltmeter, an oil gauge, a fuel gauge or a temperature gauge for, for example, I
automotive use. `
i .
Claims (19)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An illuminated indicator gauge comprising a light-transmitting dial plate having a front face, a light-transmitting pointer which is rotatable over the front face of the dial plate about an axis substantially normal to the front face and which has an inner end portion containing said axis therein and an outer end opposite to said inner end portion, and a light source located in conjunction with said dial plate for emitting rays of light toward a perimetric portion of the dial plate, wherein said dial plate has internally formed therein a reflecting surface angled at 45 degrees to said front face and said pointer has a reflecting surface formed in said inner end portion thereof and angled at 45 degrees to said axis of rotation thereof and a matte rear surface bevelled in its entirety toward said outer end of the pointer, characterized by light condensing means located between said light source and said re-flecting surface in said dial plate for condensing the light rays radiated from the light source toward the reflecting surface in the dial plate.
2. An illuminated indicator gauge as set forth in Claim 1, in which said light condensing means comprises a light collimating element having a focus located in the region of said light source.
3. An illuminated indicator gauge as set forth in Claim 2, in which said light source constitutes a substantial point source of light and in which said focus is located at said light source.
4. An illuminated indicator gauge as set forth in Claim 2 or 3, in which said collimating element consists of a convex lens located between said light source and said perimetric portion of the dial plate.
5. An illuminated indicator gauge as set forth in Claim 2 or 3, in which said collimating element is integral with said dial plate.
6. An illuminated indicator gauge as set forth in claim 2, in which said collimating element is integral with said dial plate, said collimating element being constituted by said perimetric portion of said dial plate.
7. An illuminated indicator gauge as set forth in Claim 6 in which said perimetric portion of said dial plate has a projection substantially spherically protruding away from said reflecting surface in the dial plate and toward said light source.
8. An illuminated indicator gauge as set forth in Claim 6, in which said perimetric portion has an outer face which is arcuately curved about an axis substantially parallel with the axis of rotation of said pointer.
9. An illuminated indicator gauge as set forth in Claim 6, in which said perimetric portion has an outer face which is arcuately curved about an axis substantially parellel with said front face of said dial plate.
10. An illuminated indicator gauge as set forth in Claim 2, in which said collimating element is integral with said dial plate, said dial plate being formed with an opening defined between a substantially flat internal surface located between said perimetric portion and said reflecting surface in the dial plate and an internal projection substantially spherically protruding toward said internal surface, said collimating element being constituted by said internal projection.
11. An illuminated indicator gauge as set forth in Claim 10, in which said internal projection is located between said internal surface and said reflecting surface in said dial plate and protruding toward said perimetric portion of the dial plate.
12. An illuminated indicator gauge as set forth in Claim 10, in which said internal projection is located between said internal surface and said perimetric portion of the dial plate and protruding away from said perimetric portion.
Claim 2 or 3, in which said collimating element is integral with said dial plate.
Claim 2 or 3, in which said collimating element is integral with said dial plate.
13. An illuminated indicator gauge as set forth in claim 3, in which said collimating element is integral with said dial plate, said collimating element being constituted by said perimetric portion of said dial plate.
14. An illuminated indicator gauge as set forth in Claim 13 in which said perimetric portion of said dial plate has a projection substantially spherically protruding away from said reflecting surface in the dial plate and toward said light source.
15. An illuminated indicator gauge as set forth in Claim 13 in which said perimetric portion has an outer face which is arcuately curved about an axis substantially parallel with the axis of rotation of said pointer.
16. An illuminated indicator gauge as set forth in Claim 13 in which said perimetric portion has an outer face which is arcuately curved about an axis substantially parellel with said front face of said dial plate.
17. An illuminated indicator gauge as set forth in Claim 3, in which said collimating element is integral with said dial plate, said dial plate being formed with an opening defined between a substantially flat internal surface located between said perimetric portion and said reflecting surface in the dial plate and an internal projection substantially spherically protruding toward said internal surface, said collimating element being constituted by said internal projection.
18. An illuminated indicator gauge as set forth in Claim 17, in which said internal projection is located between said internal surface and said reflecting surface in said dial plate and protruding toward said perimetric portion of the dial plate.
19. An illuminated indicator gauge as set forth in Claim 17, in which said internal projection is located between said internal surface and said perimetric portion of the dial plate and protruding away from said perimetric portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP53-25419 | 1978-02-28 | ||
| JP2541978U JPS54128450U (en) | 1978-02-28 | 1978-02-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1113063A true CA1113063A (en) | 1981-11-24 |
Family
ID=12165418
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA317,849A Expired CA1113063A (en) | 1978-02-28 | 1978-12-13 | Illuminated indicator gauge |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS54128450U (en) |
| AU (1) | AU509330B2 (en) |
| CA (1) | CA1113063A (en) |
| DE (1) | DE2903070A1 (en) |
| FR (1) | FR2418503A1 (en) |
| GB (1) | GB2015161B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813693Y2 (en) * | 1978-06-26 | 1983-03-17 | 日産自動車株式会社 | meter guideline |
| US4522069A (en) * | 1981-01-12 | 1985-06-11 | Samuel Birnbaum | Windvane |
| SE8302959L (en) * | 1983-05-26 | 1984-11-27 | Ulf Henke | DEVICE WITH A VIEWING AREA PROVIDED WITH A LIGHT-POWERFUL VIEWING ARRANGEMENT WITH A PREPARING PROCEDURE FOR SAID DEVICE |
| JPH0713572B2 (en) * | 1987-01-23 | 1995-02-15 | 日産自動車株式会社 | Meta |
| GB2262806B (en) * | 1991-12-24 | 1994-09-28 | Delco Electronic Overseas Corp | Apparatus for illuminating an instrument display |
| FR2703008B1 (en) † | 1993-03-25 | 1995-06-16 | Jaeger | LOW THICKNESS DASHBOARD, PARTICULARLY FOR MOTOR VEHICLES. |
| EP0692699A1 (en) * | 1994-07-14 | 1996-01-17 | Eta SA Fabriques d'Ebauches | Illuminated display apparatus |
| DE9420813U1 (en) * | 1994-12-28 | 1995-04-06 | Rudolf Bernt u. Söhne KG, 87600 Kaufbeuren | Pointer for a display instrument |
| JP5196310B2 (en) * | 2008-08-28 | 2013-05-15 | 日本精機株式会社 | Pointer-type instrument |
| US9312813B2 (en) * | 2012-12-18 | 2016-04-12 | Continental Automotive Systems, Inc. | Instrument panel cluster |
| US9937849B2 (en) * | 2013-12-02 | 2018-04-10 | Continental Automotive Systems, Inc. | Gauge 360 illumination lightguide |
-
1978
- 1978-02-28 JP JP2541978U patent/JPS54128450U/ja active Pending
- 1978-12-13 CA CA317,849A patent/CA1113063A/en not_active Expired
- 1978-12-18 GB GB7848842A patent/GB2015161B/en not_active Expired
- 1978-12-20 AU AU42725/78A patent/AU509330B2/en not_active Expired
-
1979
- 1979-01-26 DE DE19792903070 patent/DE2903070A1/en not_active Withdrawn
- 1979-01-26 FR FR7902110A patent/FR2418503A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2418503B1 (en) | 1982-03-12 |
| AU509330B2 (en) | 1980-05-08 |
| GB2015161A (en) | 1979-09-05 |
| AU4272578A (en) | 1979-09-06 |
| DE2903070A1 (en) | 1979-10-04 |
| GB2015161B (en) | 1982-11-10 |
| JPS54128450U (en) | 1979-09-06 |
| FR2418503A1 (en) | 1979-09-21 |
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