US2061097A - Luminous dial - Google Patents

Description

NOV. 17, 1936. R G FORDYCE 2,061,097

LUMINOUS DIAL Filed June 2, 1935 2 Sheets-Sheet l INVENTOR ATTORNEY Nov. 17, 1936. R. G. FRDYCE LUMINOUS DIAL Filed June 2, 1935 2 Sheets-Sme?I 2 A INVENTOR @y/@ I,TToRNEY Patented Nov. 17, 1.936

UNITED STATES PATENT OFFICE Radium Dial Company, New York, N. Y., a corporation of Delaware Application June 2, 1933, Serial No. 673,992

11 Claims. (Cl. 40-10.5)

This invention relates to self-luminous devices and with particularlty to methods and means for increasing the apparent optical delineation of self-luminous indicia or markings.

In various arts it is highly desirable to provide devices or mechanisms with indicia or markings which are self-luminous, and in many cases the markings must be capable of accurate visibility in subdued light orintotal darkness. For example, in the automatic telephone art, which employs selectively operable dials or the like, the subscriber or calling party is very frequently required to manipulate the dial in darkened rooms, booths, etc. It has been suggested heretofore to employ on the dial self-luminous indicia or characters. When it is considered that the eiliciency of a telephone plant is a function of the various holding times of the various trunks, selectors, etc., used in conjunction with the dial, it is of the utmost importance that any indicia employed must be of the highest degree of visible delineation, otherwise the calling party will from time to time mistake one indicia for another, with the resultant false operation of the automatic selective mechanism. Ordinary indicia of self-luminous materials have not been adopted for universal use in automatic dial systems, probably because the apparent visible delineation of the self -luminous indicia or characters is insuiilcient. It Ais a. well-known fact that if a character is painted, printed, embossed or `otherwise formed from ordinary self-luminous materials, the delineation or outline of the character is' very difficult to determine. This may be due in part to the fact that with ordinary methods of forming the self-luminous indicia, the edges or outlines are not specially delineated with the required accuracy. However, it is also an inherent characteristic of self-luminous materials themselves that they exhibit a fuzziness or blurred characteristic at the edges. This is all the more pronounced because the visible luminosity of selfluminous or phosphorescent materials is extremely low. As a result of this inherent limitation certain indicia or characters are in many cases indistinguishable from one another. For example the numeral 6 is very often mistaken for the numeral 8 and vice versa; the numerals 3 and 8 are likewise difficult to distinguish. It is obvious, therefore, that the use of ordinary selfluminousv indicia on a telephone dial or the like, may be the cause of numerous wrong connections, resulting from the fact that the calling party is unable readily to distinguish one numeralor letter from another.

lent in other arts where self-luminous indicia are employed.

Accordingly, it is a principal object of this in- The disadvantages set forth above'in connection with automatic telephone dials are also, to a greater or less degree, prevavention to provide a method and means for increasing the apparent sharpness of delineation of self-luminous indicia or markings on dials or other similar devices. 4

A feature of the invention relates to the combination of a carrier having thereon a series of self-luminous markings ,such as indicia. or the like, and optical means for enhancing the apparent delineation of such indicia when viewed 1 in a subdued light or in total darkness.

Another feature of the invention relates to a dial or similar device which is provided with selfluminous characters or indicia arranged in groups, in conjunction with an optical system for each group, whereby the apparent delineation of the 15 characters in each group is materially enhanced.

vA further feature relates to an attachment for automatic telephones or the like comprising in combination a carrier of self-luminous indicia,

and a lens carrier having a plurality of similar 2o short-focus lenses, one for each group of indicia. A further feature relates to a dial carrying a series of self-luminous indicia arranged in groups,

in conjunction with a series of lenses, one for .and proportioning of parts whereby a cheap dial attachment for automatic telephones or the like is provided having a maximum of visibility in'` subdued light.

Other features and advantages not specifically enumerated will be apparent after a consideration ofthe following detailed description and the appended claims.

i While the invention will be disclosed herein as embodied in a dial for automatic telephone systems and the like, it will be understood that this is done merely for the purposes of illustration and explanation and not by way of limitation, the inventive concept being capable of embodiment in' any situation requiring self-luminous marking having maximum visual delineation.

Accordingly, in the drawings, Fig. 1 is a top plan view of the member carrying the self-luminous markings; v

Fig. 2 is a plan view of a rotatable member that may be used in conjunction with the member of Fig. 1;

Fig. 3 is a top plan view of a lens carrier to be used in conjunction with the member of Fig. 1;

Fig. 4 is anelevational view partly in section, so

showing more clearly the relation between the movable dial and the fixed dial;

Fig. 5 is a top plan view of Fig. 4;A

Fig. 6 .shows a preferred modification of the embodiment of Fig. 4;

Fig. 7 shows a still further modification of the embodiment of Fig. 4; and

Fig. 8 is a detail sectional view of one manner of fastening the lenses in position.

Referring more particularly to Figs. 1 to 4, the numeral I represents a rotatable dial such as is ordinarily employed in automatic telephone systems and comprises a series of ilnger holes 2 to II inclusive. The construction of this dial forms no part of the invention and it suillces for the present, the dial is provided with the usual mechanism whereby during rotation it controls the operation of the usual automatic selective switch mechanism. In accordance with standard practice, each of the holes 2 to II is associated with a group of letters or numerals.

Adapted to surround the dial I is an annular- Shaped channel member (Fig. 4), of metal, bre, or other suitable material preferably, although not necessarily having its inner surface blackened o r otherwise rendered non-reflecting. Fastened to the bottom of the channel memberl I2 is an annular strip I3 which rserves as the carrier for the self-luminous markings or indicia. I4. As shown more clearly in Fig. 1, the self-luminous markings are arranged in groups, there being a group associated with each of the finger holes 2 to II inclusive. The member I2 is so mounted with relation to the member I that when the latter member is in its normal position, the finger hole 3 will be in radial alignment with the characters A-B-C-2, the hole l will be in radial alignment with the characters D-E-F-3, and so on, with the remaining groups of characters. Attached to the top of the member I2 is another annular member I5 of metal, fibre, or suitable material. The member I5 is provided with a seties of openings in which are positioned lenses I6 to 25 inclusive. 'I'he member I5 is positioned so that the lens I1 is directly above and in optical alignment with the characters A-B-C-il;

the lens I8 is directly above and in optical allgnment with the characters D-E-F--3, and so on for the remaining lenses. Any convenient means may be employed for fastening the lens carrier I5 to the member I2, and similarly, any convenient means may be employed for fastening the individualy lenses in place in the carrier I5. For example, the member I5 may consist of two separate annular plates having aligned openings to receive the lenses, with the edges of-each lens clamped between the opposite sides of the plates. On the other hand, the carrier I5 may have its l outer and inner circular edges threaded as indicated by the numerals 26, 21 (Fig. 8), and the walls of the member I2 may likewise be threaded so as to enable the lens carrier I5 to be screwed i into position. Likewise, if desired, the lenses may be mounted in individual circular carriers which may be individually and removably fastened in the member I5.

As set forth above, the characters Il are formed of self-luminous materials such as a paint containing phosphorescent materials, radium-lumilines, and If the characters in each group are relatively closely spaced, they tend to coalesce visually, thus further reducing their visual delineation. On the other hand, with the employment of lenses I6 of a short focal length, when each group of self-luminous indicia is viewed through its associated lens, the visibility and delineation of each individual character are materially enhanced, as indicated inFig. 5 of the drawings. While the explanation of this phenomena is not clearly understood, it may be due to the fact that the lenses have a resolving power which enables the body of self-luminous material in each character to be accurately imaged without imaging the irregular self-luminous particles around the edge of each character. In any event, numerous experiments prove that the use of selfluminous characters in conjunction with short focal lenses enables the characters to be positioned in closer array without rendering them blurred or vague to the eye when viewed through the lenses. Quite apart, therefore, from the increased visibility or delineation of each character there is rendered possible a saving in luminescent material, since the self-luminous characters may be grouped closer together and may be of much characters. In other words, each lens is designed as to focal length and aperture, so that the apparent delineation of the individual characters in each group is materially increased.

Instead of mounting the designation strip I3 in a plane parallel to the dial I as in Figs. 1l to 5, this designation strip may be mounted at an angle to the dial so as to enable all the indicia to be viewable simultaneously through the respective lenses, from a common point. Thus, as indicated in Fig. 6, the strip I3 carrying the selfluminous indicia Il is attached to the annular channel member I2 at a slight angle. Similarly, the individual lenses I6, I1, etc., are mounted substantially parallel to the strip I3 so that an observers eye at the point P, for example, is capable of viewing all the indicia I 4 simultaneously through the respective lenses. While Fig.

v6 shows one specific manner of mounting the designation strip and the lenses at an angle to .the axis of the dial, it will be understood that this is merely illustrative, and that any other well-known manner of positioning these parts in desired relation as set forth may be employed.

Instead of viewing the indicia directly through the associated lenses, it may be desirable to interpose a reflector or mirror between the indicia and the lenses. Thus, as shown in Fig; '7, the annular channel member I2 carrying the individual lenses I6, II, etc., is provided with a reiiecting plate 28, which is preferably of a polished metal or the like, although, if desired, a glass mirror may be employed. The designation strip 29 carrying the indicia instead of being in the form of a nat annular disc as in Figs. 1 to 5, is in the form of a cylinder attached to the inner wall of the annular member I2. Thus the indicia on the member 29 are in planes at right angles to the the indicia and the lenses is effectively increased.

It will be understood, of course, that the lenses in the embodiment of Fig. 7 may be mounted parallel to the reector 28, as described above iny connection with Fig. `6, so as to enable the reiiected indicia to be viewed simultaneously from f a common point.

While various specic arrangements and ma-l terials have been mentioned hereinabove, it will vbe understood that the invention is not limited thereto. For example, the term self-luminous as employed herein, is intended to cover any I mixture containing a phosphorescent, a radium luminescent compound, or similar materials. Similarly, while a single lens is shown associated with each group of indicia, this is merely illustrativeand, if desired, a combination of lenses may be employed. It will be also understood that the various groups of indicia, instead of being mounted on a single plate or strip I3, may be mounted on individual strips so as to be replaceable from time to time. If desired, a protective covering in the form oi an annular strip of celluloid or other transparent material may be positioned over the lenses to protect them from scratching, breaking, etc.

Various other changes may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. In a device of the character described, a rotatable dial, a carrier surrounding said dial having thereon a plurality of self-luminous indicia, a plurality of short focus lenses, and annular means for mounting each lens a predetermined fixed distance from a corresponding area of said carrier for resolving the light from the indicia to enhance the visual delineation thereof.

2. In a device of the character described,

means defining an annular channel, a strip carrying radium-luminous material positioned within said channel, lclosure means for said channel and a plurality of spaced 'short-focus lenses mounted in said closure means in predetermined spaced relation to said strip.

3. In a device of the character described, the combination of an annular channel member, another member carrying a series of self-luminous indicia, said other member being mounted within said channel member at an inclined angle, to the axis of said annular member, a. plurality of lenses, and means for mounting said lenses in optical alignment with said indicia.

4. In combination, a rotatable member, a xed member surrounding said rotatable member. a strip carried by said fixed member at an inclined angle to the rotational axis of said rotatable member, indicia on said strip, and a plurality of lenses mounted each in optical alignment with associated indicia, whereby all said indicia may be simultaneously viewed from a common point through said lenses.

`5. In-combination, a rotatable selective device having a plurality of selecting members positioned therearound, a xed designation dial surrounding said member and having a plurality of groups of self-luminous indicia, eachy group being in alignment with a corresponding one of said members,

said indicia being mounted in a plane at an inclined angle to the plane ofv rotation of said dial, a plurality of short-focus resolving lenses each in optical alignment with one of said groups of indicia, and reecting means between the indicia and lenses to enable the reflected Aindicia to ybe viewed through the lenses.

6. In a device of the character described, the combination of an annular channel shaped member, self-luminous indicia arranged in spaced groups on `the interior of said member, closure means for said channel shaped member having a plurality of spaced openings therein, a shortfocus lens mounted in each opening in optical alignment with a corresponding group of indicia, said lenses and closure member cooperating with said channel member to substantially completely enclose said indicia.

7. In combination an automatic telephone dial, a member surrounding said dial said member carrying a'plurality of self-luminousindicia arranged in radial groups, a plurality of short focus lenses, means for mounting each lens a predetermined iixed distance from a corresponding one of said groups and in optical alignment therewith, and light reecting means between said indicia and said lenses for reecting the light from each group through the corresponding one of said lenses, said reflecting means being mounted at an inclination to the axis of rotation of said dial.

8. In combination a rotatable dial, a strip carrying la plurality of self-luminous indicia arranged in spaced groups, a plurality of short focus lenses, means i'or mounting said lenses at an inclination to the axis of rotation of said dial so that all said indicia may be equally viewed' through the lensesl from a single point, the distance of said lenses yfrom said indicia and the focal length and aperture of the lenses being so proportioned as to increase the apparent delineation of said indicia.

9. In combination, a selective rotatable dial, a designation member surrounding said dial and iixedly mounted with relation thereto, a plurality of spaced groups of self-luminous indicia on said member, a plurality of short-focus lenses, and common means on said member for xedly mounting each lens in alinement with a corresponding one of said groups and at a predetermined distance therefrom, said means substantially completely enclosing said indicia.

10. In combination, a carrier bearing thereon in localized areas self-luminous indicia, a plurality of short-focus lenses, one associated with each area for increasing the apparent delineation oi.' said indicia, means for mounting said lenses 'a predetermined iixed distance from each of said areas, and meansy extending upwardly of said carrier for supporting said lens mounting means.

11. In combination, an annular carrier bearing thereon in localized areas radium-luminous indicia, a light-collecting and resolving member associated with each area for enhancing the discernibility of said indicia, and annular support means for supporting said members a predetermined fixed distance from their associated areas.

RUFUS G. FORDYCE.

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