US3858341A

US3858341A - Segment type, electric light figure indicator

Info

Publication number: US3858341A
Application number: US312983A
Authority: US
Inventors: Yasuo Wakabayashi
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-12-08
Filing date: 1972-12-07
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07
Also published as: JPS4870574U; GB1363169A; DE2259641A1; DE2259641B2; CA977144A; FR2167002A5

Abstract

A compact device for displaying an illuminated numerical digit or other figure having a plurality of light sources, each light source housed in a separate compartment of the device and adapted to illuminate one elongated section of the figure with uniform brightness. Each compartment has a triangular cross-section in a plane parallel to the length of the device with the light source mounted near the apex of the triangle and the elongated figure section located near the base of the triangle. All surfaces within each compartment are mirror-like, coated with a substance which forms a light-reflecting surface. An inclined lightreflecting surface is provided in each compartment adjacent to the figure section and triangle base.

Description

Wakabayas i Jan.7,1975

[ SEGMENT TYPE, ELECTRIC LIGHT FIGURE INDICATOR 21 Appl. No.1 312,983

[30] Foreign Application Priority Data Hammell 340/336 X Ruppert 40/130 K Primary Examiner Robert W. Michell Assistant Examiner-John F. Pitrelli Attorney, Agent, or Firm-Lane, Aitken, Dunner & Ziems [57] ABSTRACT A compact device for displaying an illuminated numerical digit or other figure having a plurality of light sources, each light source housed in a separate compartment of the device and adapted to illuminate one elongated section of the figure with uniform brightness. Each compartment has a triangular cross-section in a plane parallel to the length of the device with the light source mounted near the apex of the triangle and the elongated figure section located near the base of the triangle. All surfaces within each compartment are mirror-like, coated with a substance which forms a light-reflecting surface. An inclined light-reflecting surface is provided in each compartment adjacent to the figure section and triangle base.

5 Claims, 7 Drawing Figures Patented Jan. 7, 1975.

' 2. Sheets-Sheet l PRIOR ART PRIOR ART Patented Jan. 7, 1975 2 Sheets-Sheet 2 FIG. 3

FIG. 4b

FIG. 40

SEGMENT TYPE, ELECTRIC LIGHT FIGURE INDICATOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a segment type, illuminated figure display device and more particularly to such devices which utilize miniature electric bulbs as the light source. The figure represented may be a numerical digit, 1 through 10. The nature of the digit is determined by which segments are illuminated and may be changed to represent other digits in succession by turning the appropriate lights off and on.

2. Description of Prior Art The conventional segment type, electric light figure indicator, has seven elongated segments arranged in mosaic fashion to represent a figure. Non-uniform brightness is likely to occur throughout the length of an individual elongated section because of the proximity of the light source to the display surface. Accordingly, the light source (electric bulb) is usually located inside the indicator at a distance from the display surface sufficient to produce the required uniformity of illumination, thus resulting in a device having a large thickness or depth and bulk. Excessive thickness and bulk are undesirable in such devices because many modern applications require compactness in display devices of this type.

SUMMARY OF THE INVENTION The present invention provides a segment type, electric light figure indicator having seven illuminated segments in which the casing of the indicator is divided into seven flat compartments each having a triangular lateral cross-section in a plane along the length of the device and having a thickness or depth only slightly base portion of the triangle is inclined (at an angle) I with respect to the display surface to form a reflecting surface for the light, so that the electric light emanating from the bulb is reflected by the inclined wall so as to hit the elongated figure section at a right angle. The in terior walls of the triangular shaped compartment are coated with aluminum (e.g. by vapor deposition) or chromium plating to provide mirror surfaces surrounding the light source. This construction provides uniform brightness throughout the length of each elongated figure segment. As a result, the thickness or depth of the device may be minimized.

Accordingly, it is an object of the invention to provide a segment type, electric light figure indicator having a casing of a small thickness or depth, yet providing a wide figure indicating surface.

It is a further object of the invention to provide a segment type, electric light figure indicator which gives uniform brightness throughout each elongated figure section appearing on the surface of the indicator.

It is a still further object of the invention to provide a segment type, electric light figure indicator which presents an indicated figure of a desired color.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1(a) is a front elevation of a conventional mosaic type, seven segment electric light figure indicator;

FIG. 1(b) is a cross-sectional view of the indicator of FIG. 1(a), taken along line A-A thereof;

FIG. 2(a) is a front elevation of a segment type, electric light figure indicator of the present invention;

FIG. 2(b) is a cross-sectional view of the indicator of FIG. 2(a), taken along line BB thereof;

FIG. 3 is a front elevation, partially in cross-section, of the device of FIGS. 2(a) and 2(b);

FIG. 4(a) is a front elevation of another embodiment of the device of the invention; and

FIG. 4(b) is a cross-sectional view of the indicator of FIG. 4(a), taken along line CC thereof.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1(a) and (b) illustrate a conventional prior art segment type illuminated figure indicator for comparison and better understanding of the features of the indicator of the present invention. The conventional mosaic display device has seven illuminated segments. An elongated figure segment is shown at 1. A light source, i.e., a miniature electric bulb 2, is spaced a relatively large distance from the elongated figure section surface in order to achieve a well distributed brightness thereon. If the light source were closer to the figure section 1, the brightness throughout the length of that segment would be increased as a whole to some degree, but the brightness at the both extremities of the figure section would become considerably lower relative to the center portion thereof. This effect, uneven brightness of the figure section, would present an illuminated figure having varying degrees of brightness at various positions on the mosaic surface. Therefore, the depth of the casing 3 is determined by the required uniformity of brightness, thus requiring a display device having a relatively large depth of thickness, as compared to the size of the illuminated figure.

FIGS. 2 and 3 illustrate a mosaic display device of the present invention. The casing 4 is: formed with seven compartments each having a triangular cross-section and a depth approximating the height or width of the light source- Each compartment contains an electric bulb 7 and has one elongated display surface 5 which forms one segment of the illuminated figure. A slanted reflecting wall 6 forms one compartment wall and meets the display surface of the device at an inclined angle of about 30 to about preferably at 45. The compartment is defined by the surfaces of

partition walls

8 and 9, by bottom surface 10, and by the interior surface of an aluminum plate 11. The aluminum plate 11 has a number of mosaic openings or slots and covers the top opening of the casing 4. The

surfaces

6, 8, 9, l0 and 11 of each compartment are coated with aluminum or chromium plating to form reflecting mirror surfaces.

On top of the aluminum plate 1]. is provided a semitransparent white or frosted glass sheet 12. Two lead or jimmet wires 13 leading from each miniature bulb 7 are soldered directly onto the printed circuit base board 14, thus eliminating the need for a socket or receptacle for each bulb and thus minimizing the thickness or depth required for the display device. A connecting terminal is provided as an extension of the base board 14 for the same purpose.

In operation, when the miniature electric bulb 7 is lit, the light therefrom is reflected off of the

various mirror surfaces

6, 8, 9, 10 and 11 and eventually issues through the elongated, confined mosaic opening 5 to illuminate the semitransparent frosted glass sheet 12 from behind with a uniform intensity of illumination. The distance between the light source 7 and the glass sheet 12 is relatively small, yet produces a uniform intensity of illumination throughout the length of the elongated, confined mosaic surface as viewed from the front of the device.

In the embodiment of FIGS. 2(a) and 2(b), the electric bulb 7 is located near the apex of the compartment triangle and at a right angle to the figure display surface.

FIGS. 4(a) and 4(b) show another embodiment of the present invention, wherein the electric bulbs are mounted parallel to the display surface. The thickness or depth of the device is smaller than that of the embodiment shown in FIGS. 2(a) and 2(b). The more shallow depth is made possible by the disposition of the bulbs. The depth of the compartment, in this case, is only slightly greater than the width of the bulbs used. The electric bulbs in this embodiment are of a size having a diameter of 2.4 mm or 3.15 mm, with the rated amperage and voltage being 0.15 A and 5 V, respectively, and having a service life in the neighborhood of 20,000 hours. Shown at 16 is a light source consisting of a miniature electric bulb. The device is further provided with a printed circuit base board 17, a reflecting surface 18 inclined at an angle of 45 to the display surface, and an aluminum plate 19 having an elongated, confined mosaic opening 20 therein. When the surface 18 is colored red or green with a colored lightreflective coating, the red or green light will project through the elongated mosaic opening 20, if a semitransparent glass sheet is not used. This enables the presentation of a colored, illuminated figure.

As is apparent from the foregoing description, there is provided a segment type device for the display of illuminated figures, having a casing of a-shallow depth, yet providing a relatively wide figure display surface with uniform brightness throughout the elongated mosaic openings. A further aspect of the present invention is that it provides a colored, illuminated figure.

The foregoing description and examples are presented for purposes of illustration only and are not intended to limit the scope of the invention as defined by the appended claims.

What is claimed is:

1. A segment type, electric light alpha-numeric figure indicator, comprising:

a casing having seven flat compartments, each of said compartments having a cross-section in a lateral plane in the shape of a triangle, said triangle having an apex angle and a base side opposite said angle;

electric bulbs each housed in each of said compartments and located therein close to and in the apex angle of said triangle, the height or width of said electric bulb being slightly smaller than the depth of said casing;

a cover plate covering the top opening of said casing and having elongated, confined mosaic openings therein, which permit light emanating from the electric bulbs to shine therethrough, each opening located parallel to and in front of the base side of said triangle and arranged so as to collectively form an alpha-numeric figure;

said compartments each having a reflecting wall inclined to said cover plate at an angle of about 30 to 60, said inclined walls being located immediately behind said elongated, confined mosaic openings; all interior surfaces of said compartments having reflecting mirror surfaces; and

light diffusing means covering said mosaic openings.

2. A segment type, electric light figure indicator as set forth in claim I, further comprising a printed circuit base board forming the base of said casing and lead wires on said bulbs soldered to said printed circuit board.

3. A segment type, electric light figure indicator as set forth in claim 2, further comprising a connecting terminalfor said indicator in the form of an extension of said printed wiring base board.

4. The indicator of claim 1 wherein said lightdiffusing means is frosted glass.

5. The indicator of claim 1 wherein each compartment is defined by a plurality of reflecting mirror surfaced walls comprising said cover plate, said inclined wall, two walls forming said apex angle and perpendicular to said cover plate and one wall parallel to said cover plate.

Claims

1. A segment type, electric light alpha-numeric figure indicator, comprising: a casing having seven flat compartments, each of said compartments having a cross-section in a lateral plane in the shape of a triangle, said triangle having an apex angle and a base side opposite said angle; electric bulbs each housed in each of said compartments and located therein close to and in the apex angle of said triangle, the height or width of said electric bulb being slightly smaller than the depth of said casing; a cover plate covering the top opening of said casing and having elongated, confined mosaic openings therein, which permit light emanating from the electric bulbs to shine therethrough, each opening located parallel to and in front of the base side of said triangle and arranged so as to collectively form an alphanumeric figure; said compartments each having a reflecting wall inclined to said cover plate at an angle of about 30* to 60*, said inclined walls being located immediately behind said elongated, confined mosaic openings; all interior surfaces of said compartments having reflecting mirror surfaces; And light diffusing means covering said mosaic openings.

2. A segment type, electric light figure indicator as set forth in claim 1, further comprising a printed circuit base board forming the base of said casing and lead wires on said bulbs soldered to said printed circuit board.

3. A segment type, electric light figure indicator as set forth in claim 2, further comprising a connecting terminal for said indicator in the form of an extension of said printed wiring base board.

4. The indicator of claim 1 wherein said light-diffusing means is frosted glass.