Reflective Readout Device

Abstract

A display device including a body having a plurality of light producing or color changing areas. The light producing or color changing areas are arranged, relative to each other, to provide an information display, for example an alpha-numeric readout, or a visual indication of the operational characteristics of a machine or instrument. Each light producing area includes a source of light or color copy and means for spreading, via reflective surfaces, the light or color.

Parent Case Text

This is a continuation, of application Ser. No. 868,854, filed Oct. 23, 1969, now abandoned.

Description

SUMMARY OF THE INVENTION

This invention relates to a display device utilizing a light source, internal or external, and reflective areas or surfaces to spread the light for providing an informative display.

A primary purpose of the invention is a display device of the type described including a plurality of light producing areas, each having a light source and a reflecting surface in the shape of a truncated pyramid.

Another purpose is a display device of the type described in which a plurality of minute light bulbs, for example "grain of wheat" light bulbs, may be arranged, relative to adjacent reflective surfaces, to provide a substantially continuous light display.

Another purpose is a display device of the type described including a plurality of light enclosures, each having indicia, such that when each light enclosure is illuminated, an adjacent reflecting surface displays the indicia.

Another purpose is a display device of the type described in which an arcuate reflecting surface may be utilized to display different indicia, with each indicia being selectively illuminated through a light enclosure, one wall of which may support the indicia. Other purposes will appear in the ensuing specification, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated diagrammatically in the following drawings wherein:

FIG. 1 is a perspective of one form of reflective display utilizing a plurality of light producing areas,

FIG. 2 is a section along plane 2--2 of FIG. 1,

FIG. 3 is a diagrammatic illustration of one arrangement of light producing areas,

FIG. 4 is a diagrammatic illustration, similar to FIG. 3, illustrating a different arrangement of light producing areas,

FIG. 5 is a front plan view of a second form of display device utilizing a plurality of light producing areas,

FIG. 6 is a section along plane 6--6 of FIG. 5,

FIG. 7 is a rear view of the light enclosures utilized in FIG. 5, with the cover removed,

FIG. 8 is a perspective of a variable transmission compound tape used to provide illumination for the structure of FIGS. 5, 6 and 7,

FIG. 9 is a rear view, similar to FIG. 7, showing a modified form of the invention.

FIG. 10 is a vertical section, similar to FIG. 6, showing a modified form of the invention.

FIG. 11 is a vertical section, showing a variation on the device of FIG. 6,

FIG. 12 is a section, similar to FIG. 10, showing yet a further modified form, and

FIG. 13 is a front view of the cup used in FIGS. 11 and 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Considering first that form of the invention illustrated in FIGS. 1-4, a display device is indicated generally at 10 and may include a body 12, preferably formed of aluminum or a suitable material forming a heat sink which can be cast or molded. Behind the body 12 is a printed circuit board 14, the function of which will be described hereinafter. Directly on top of the body 12 is a layer 16 of a diffusing material which may be formed of any convenient translucent material such as plastic, glass, quartz, etc. On top of the layer 16 is a filter 18 which may be used to control the color of light which will be displayed. For example, if it is desired to have a red display, or a blue display, then an appropriate filter will be used. At the front of the display device 10 is a layer 20 which may be conveniently formed of a smokey acrylic material or black glass, which has a tendency to block out light or provide a generally black face except for those areas which are illuminated from within by the light sources described.

Looking particularly at FIG. 2, the body 12 may include a plurality of light producing areas 22, each of which have a point source of light 24, which may conveniently be "grain of wheat" type of light bulbs, or any other small, low power light source. The light producing areas 22 may be in the shape of truncated pyramids. As such, there will be a peripheral reflecting surface 26. The reflecting surface 26 will extend peripherally about the point source of light 24 and generally the point source of light will be in the center. When the reflecting surface 26 takes the form of a truncated pyramid there will be four sides, shown in detail in FIGS. 3 and 4. In some applications, rather than being a truncated pyramid, the reflecting surface 26 may be a truncated cone or the frustum of a cone. What is important is to have a reflecting surface which extends peripherally about the point source of light and which is capable of increasing the total light area or spreading the light to provide uniformity. Arrows 25 indicate the directions of the reflected light. The reflecting surface can be various colors but should be highly reflective. For example, highly polished black stone could reflect satisfactorily.

In FIG. 3, each of the light producing areas 22 is arranged to form the letter O. As illustrated in FIG. 1, the display device is forming the trademark of Oak Electro/Netics Corp., assignee of this invention, although obviously this is merely an illustrative example. The various light areas 22 may be arranged to be successively illuminated, illuminated all at once, or in any desired sequence. The printed circuit board 14 optimizes the packaging and interconnection of the light sources 24 and also provides input control conductors. The manner of connection forms no part of the present invention. What is important is that there be light sources which can be connected up in any suitable manner. Light pipes may be used in place of bulbs.

In FIG. 4 the various light producing areas 22 are arranged to provide alpha-numeric information. With the array shown in FIG. 4, any number or letter of the alphabet can be formed, depending upon the interconnection of the various light sources on the printed circuit board and the input signals from electrical and/or mechanical logic. For example, for the letter O, all of the outside light producing areas would be illuminated. For the letter T, the top two light producing areas and the two center vertical light producing areas would be illuminated. It is known in the art that an array such as shown in FIG. 4 can provide any alpha-numeric display. Not only can there be a single letter or single number, but, depending upon the programming of the printed circuit board and the electrical or mechanical logic, there can be successive displays to provide a digital or alpha-numeric readout.

In essence, a plurality of light producing areas, each including a peripheral reflecting surface and a point source of light, are used to provide a display device. A diffusing layer is placed over the cast aluminum body 12 to further diffuse the light and give each light producing area the appearance of a bar of uniform light. In some applications filter 18 and the diffusing layer 16 may be integral. The filter 18 provides color. The black glass cover 20 gives a black appearance for the display, masking the interior until such time as there is illumination provided by the light producing areas. When the device is operated, it will mask the non-illuminated areas. The total combination is compact, highly reliable and provides high volumetric efficiency. The body 12, if it be aluminum, serves not only as a reflector to spread out the light from each point source, but also as a heat sink which substantially increases the life of each light bulb and as a structure for mounting, masking and packaging purposes.

Turning to that form of the invention illustrated in FIGS. 5-8, a portion of an automobile speedometer is indicated generally at 30. The various speeds may be carried by an indicia tape 32, with the information from the indicia tape being displayed at the front image surface 34 by a reflecting surface 36. The reflecting surface and the image surface are part of an arcuate prism, with the indicia tape 32 being adjacent or affixed to the object surface 38 of the prism. As in other forms of the invention, arrows are used to indicate the direction of reflected light. An arm 35 carries a pointer 37 which moves adjacent the object surface 38 to indicate speed. In some applications the indicia may be molded into the object surface 38. Directly below the reflecting surface 36 is a second reflecting surface 40 which may have an object surface or face 42 and an image surface or image face 44. Positioned along the curved or arcuate object surface 42 is a second indicia tape 46 which may be divided into sections, with each section relating to one of the control functions of an automobile, for example door lock, brakes, high beams, temperature, oil and battery.

Looking particularly at FIG. 7, which shows the back of the speedometer with the cover removed, the indicia tape 46 may form one wall of a plurality of light enclosures or light producing areas, each of which are indicated at 48. Each of the light enclosures 48 are formed by divergent side walls 50 and 52 and an inner end wall 54, positioned opposite the indicia tape 46. As shown in FIG. 8, the inner end wall 54 may be formed of a variable light transmission compound, which is applied to a clear tape. Note the plus and minus signs on opposite sides of the tape. When an appropriate voltage is applied to any one section of the tape, in the proper polarity, that particular section of the tape changes from opaque to translucent. Thus, it becomes light transmissive. A single light source 58 at the center of the wedge-shaped light enclosures 48 can then pass light into any one or more of the light enclosures, depending upon which section or sections 56 of the tape 54 are illuminated. Arrows 57 indicate the direction of light passing through a translucent area and arrow 59 indicate light which is stopped by opaque areas. The sides 50 and 52 may preferably be formed of aluminum, or metalized plastic, again to provide the desired light reflective structure and a heat sink. The light will be directed through the end wall 54 to the indicia 46, the illuminated indicia will then be directed by reflecting surface 40 to the front image surface 44. Thus, within the body 60, which may be formed of aluminum, there are a plurality of light enclosures or light producing areas, each of which can be selectively illuminated to display indicia at a desired location.

FIG. 9 shows an alternative form of the invention. In this case there are separate light sources 62, which again may be of "grain of wheat" type of miniature light bulbs, positioned within each light enclosure 48. The light bulbs 62 may be arranged for selective illumination, in the same manner as the sections of the variable transmission compound tape 54. Thus, when the condition of any control function of an automobile is to be displayed, the light bulb 62 pertaining to that function will be turned on to illuminate the indicia tape 46 for display at the front image surface 44. Arrows 63 show the path of light from the illuminated bulb.

FIG. 10 shows a modified form of the invention, similar to the illustration of FIG. 6, in which an object surface 70 having indicia 72 forms an angle slightly larger than 90.degree. with an image surface 74. A reflecting surface 76 is effective to direct the indicia 72 in the direction of the arrow 78. Because the path of the light reflected from surface 76 is not perpendicular to image surface 74, refraction will cause the light path to be bent at the image surface as shown by arrow 78. A pointer 80 attached to an arm 82 functions in a manner similar to the pointer 37 of FIG. 6. The other elements of the structure in FIG. 10 may be the same as that of FIG. 6.

FIG. 11 shows yet a further form of reflective readout device. An annular reflective prism 84 may have a reflecting surface 86, an image surface 88 and an object surface 90. The object surface 90 may mount an indicia tape or the like 82 which may include suitable alpha-numeric information, for example that illustrated in FIG. 5 for an automobile speedometer. Within the circular prism 84 is a cup 94, which may be driven by a motor or the like 96, which may be a conventional speedometer drive. The cup 94 has a transparent flat surface 98 and a transparent circular surface 100 covered by tape sections 102 and 104. The tape section 102, which may be colored, for example red, is transparent, whereas the tape section 104 may be black or opaque. The drive 96, as is conventional in odometers, can provide a visual indication of the speed of an automobile. The dividing line between the transparent red tape section 102 and the opaque section 104 is so arranged that this joint moves as a pointer would in a regular speedometer. Thus, the speed of the car will be visually indicated in red numerals and by a red band, whereas the higher speeds can have a black background. As an alternative, the section 104 may be a clear transparent tape and thus the red band would be used to indicate the speed with the higher speed indications being also visible to the driver, but not in any particular color. A further modification is to have one of the sections green and the other red, again to visibly indicate speed by varied colored bands.

In FIG. 12, a similar reflective readout device, for example for use as a speedometer, includes a pair of prisms 106 and 108, both circular in form. A cup 110, driven by a shaft 112, which again may be connected to the odometer drive, may be constructed in a manner similar to that shown in FIG. 13. Extending upwardly from the cup 110 is an arm 114 having a pointer 116. The position of the pointer 116 will be reflected to the front face 118 by the reflecting surface of prism 106, whereas the color on the sides of the cup 110 will be reflected to the front face 118 by the prism 108. A suitable indicia tape may be added which would provide the various speeds and other indications that are necessary to provide control information to the driver. The device in FIG. 12 functions in a like manner to that of FIG. 11, except in this case there is, in addition, a pointer to go along with the colored band indication formed by the cup 110.

In both forms of the invention there are a plurality of light producing areas. In each case there are means which spread the light. In one construction, indicia is displayed by the light. In the other construction, the display is the arrangement and illumination of the various light producing areas.

The invention should not be limited to any particular material or to any particular type of light source. What is important is to provide light producing areas arranged to provide an informative display. In like manner, the invention should not be limited to a speedometer construction or to any particular use of the light producing areas.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there are many modifications, substitutions and alterations thereto within the scope of the following claims.

Claims

I claim:

1. In a display device, a body, a plurality of arcuately arranged wedge-shaped light producing enclosures in said body arranged side by side about a common center, a source of light for said light producing enclosures, an arcuate reflecting surface and an arcuate image surface, said image surface forming an arcuate display surface at the exterior of the body, a curved object surface forming a coextensive outer wall for each of said light producing enclosures, indicia positioned adjacent said object surface and along the coextensive wall of each light producing enclosure, with the indicia being along one wall of each enclosure and the light source being at the opposite wall of each enclosure, the light from each light producing enclosure causing the indicia associated therewith to be displayed by said reflecting surface at the image surface.

2. The structure of claim 1 further characterized in that each light producing enclosure has a separate light source.

3. The structure of claim 1 further characterized by and including a single light source providing illumination for all of said light producing enclosures.