US2453064A

US2453064A - Magnifying reading unit

Info

Publication number: US2453064A
Application number: US576178A
Authority: US
Inventors: George M Cressaty
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-02-05
Filing date: 1945-02-05
Publication date: 1948-11-02
Anticipated expiration: 1965-11-02

Description

' W i Y #5 Nov. 2, 1948. s. M. CRESSATY MAGNIFYING READING UNIT 2 Sheets-Sheet 1 Filed Feb. 5, 1945 FIG. I

FIG,.3

FIG.5

FIG. 4

GEORGE M. CRESSATY INVENTOR ATTORNEY Nov. 2, 1948. s. M. CRESSATY 2,453,064

V MAGNIFYING READING UNIT Filed Feb. 5, 1945 2 Sheets-Sheet 2 FIG. 6 FIG, 7

GEORGE u. ORESSATY INVENTOR ATTORNEY Patented Nov. 2, 1948 UNITED STATES PATENT OFFICE MAGNIFYING READING UNIT George M. Cressaty, New York, N. Y. Application February 5, 1945, Serial No. 576,178

6 Claims. 1

This invention relates to optical units and systems used to assist in reading printed pages and more particularly'to magnifying lenses in conjunction with prisms for directing a magnified image toward a reader.

Reading glasses made with spherical and cylin drical surfaces are old in the art. Some have supports to keep them in the proper position for reading while some are made with elaborate adjustable means for varying their position. The ordinary reading glass, however, has one serious defect; when used in the usual manner, the illumination on the page to be read is generally quite .poor. This is due to several causes: the reading glass itself gets in the way of the source of illumination and causes a shadow, and the condensing properties of the glass concentrate the available light to form a bright spot close to the portion that is to be read. The combination shadow and bright spot produce an illumination that is tiring on the eyes and makes reading quite difllcult.

The invention broadly consists of a combination prism and cylindrical lens mounted on supporting legs and so aligned as to provide adequate illumination no matter where the source of light is placed. In further detail, a cylindrical lens is formed on top of a prism which may have an angle of 30 degrees between faces. This combination is mountedfwith the plane surface at an angle of about 60 degrees to the reading plane. As will be shownhereinafter, this design results in a reading unit that not only magnifies the reading matter but also bends the light rays toward the reader and increases the degree of illumination.

One of the main objects of the invention is to improve the design of reading units so that increased illumination is' present on the reading plane when viewed by the invention.

Another object of the invention is to improve the lighting characteristics of a reading unit whereby the illumination will be evenly distributed over the plane to be read.

Another object of the invention is to enable one to read a paper or book lying flat on a table while seated in'a normal position in front of the table. When the invention is in use it is not necessary to bend directly over the reading unit to see what is on the reading plane. Reading is done at an angle.

Still another object of the invention is to enable one to view the entire length of several lines on a page or letter without moving the reading unit.

ill

Another object of the invention is to provide a reading unit with a fixed focus. No adjustment is necessary when the unit is in use.

Another object of the invention is to reduce distortion at the edges of the field of view.

Other obiects and structural details of the invention will be apparent from the following description when read in connection with the accompanying drawings, wherein,

Fig. 1 is a front view of the reading unit.

Fig. 2 is a cross sectional view of the reading unit taken along line 2-2 of Fig.- 1.

Fig. 3 is an end view of the unit.

Fig. 4 is a diagram showing the passage of light rays through the reading unit.

Fig. 5 is a diagram showing how illumination is obtained when the light is coming from a direction 30 degrees from the plane of the object.

Fig. 6 is a diagram showing how illumination is obtained when the light is directed 60 degrees from the plane of the object.

Fig. '7 is a diagram showing how illumination is obtained when light isdirected from a point almost directly above the reading unit.

Fig. 8 is a plan view of the reading unit.

Referring now to Figs. 1, 2, and 3, the reading unit consists of a long transparent rod II having a curved surface I! on its uppermost portion. In the preferred form (shown in Fig. 2) this surface has a radius of 3 inches but this length will vary with materials and degree of magnification. While the drawing shows a cylindrical surface, the scope of the invention is not confined to this limitation. i lens, such as spherical, aspherical, 0 may be used in conjunction with the prism as long as the lens is large enough to cover a major portion of the surface of the prism. In the drawings the lens surface I! is superimposed on the prism surface so that a chord drawn between the edges of the lens makes an angle of about 30 degrees with the reading plane. The chord so drawn is the trace of the sagittal plane of the lens surface.

A plane surface I3 forms the underside of the unit II. This surface is at an acute angle of greater than 15, preferably about 30 degrees from the non-parallel sagittal plane of the lens surface I! and hence forms a prism which bends the light toward the reader as will be explained later. The angle of surface 13 also acts as a reflecting surface in directing rays of light to illuminate the characters to be viewed.

-A front surface ll makes a slight angle with the vertical but no useful light rays pass through this face.

siARCH ROOM At each end of the reading unit, plate-like supporting legs I! and I. are shown castintegral with the lens. This type of construction is for convenience only as the legs may be cemented or mechanically attached. The bottom sides Ila and IBa of these legs rest on the paper to be read as does a plane surface II. These three surfaces, Ia, liar, and I! keep the lens in its proper position and also serve in the manner of a. paper weight since they may be used to keep a piece of paper, such as a letter, in the proper plane for reading.

In Fig. 4 the lens rod I I is shown mounted on a reading plane I8. The rays of light from a point 20 on the plane I8 may be traced by following the bundle of rays 2| as indicated in the figure. At the first surface I3 all the rays are bent to the right and continue through the lens in a direction which is divergent from a point 22 below the plane of the paper. After traversing the lens block the rays emerge through the cylindrical surface I2 and are refracted again so that they proceed to the eye as though they originated at the point 23. The degree of magnification may be changed by altering the curvature of the exit surface I2, while the degree of bending may be changed by altering the angle of the prism.

In Figs. 5, 6, and 7 various conditions of illumination are shown and the results obtained from each are indicated. Fig. 5 shows the reading unit I I and paper plane I8 illuminated by rays of light that come from a point in front of the reader and make an angle of 30 degrees with the horizontal. Some of the light which strikes the surface I3 will enter the lens block and travel toward the cylindrical surface I2. However, this light will not be in evidence because most of it will be reflected from surface I2 by total reflection and the remainder will emerge at an angle that will not be seen by the reader.

A large percentage of the light will be directed vertically downward and illuminate the reading plane I8 in an even and satisfactory manner.

Fig. 6 illustrates the reading unit II and paper plane I8 illuminated by rays of light that come from a point in front of the reader but make an angle of 60 degrees with the horizontal. In this condition there is no. reflection from the face I3 and all the illumination on plane I8 is derived from direct radiation.

Fig. 7 shows the reading unit I I and paper plane I8 illuminated by rays which come from a source placed almost directly above the glass. All the illumination is due to light which is refracted through the reading glass. The figure illustrates how the rays are directed to the proper area but not in such a concentrated manner as to produce a bad light spot.

Conventional magnifying glasses of the bullseye type, in contrast, when subjected to light sources positioned as in Figs. 5-7, yield bright and shadow areas on the reading plane, and the resulting illumination. thereon is not nearly as uniform as obtained with my unit.

The reading unit may be made of any transparent material. In addition to glass, there are several transparent plastics, such as Lucite and Plexiglas, which lend themselves particularly Well to such a use because they are light in weight and will not break if dropped on the floor.

While I have described what I consider to be a highly desirable embodiment of my invention, it is obvious that many changes in form could be made without departing from the spirit of the invention, and I, therefore, do not limit myself to the exact form herein shown and described nor to anything less than the whole of my inventionas hereinbefore set forth, and hereinafter claimedr.

I claim:

l. A reading lens comprising a supporting s face for resting on a reading plane, a planar surface extending upwardly and rearwardly from the rear edge of said supporting surface over the reading matter to refract rays from the reading matter. a second obturating surface extending upwardly from the forward edge of said supporting surface, and a curved upper magnifying surface extending downwardly and forwardly between said two upwardly directed surfaces.

2. A reading lens comprising a supporting surface for resting on a reading plane, a planar surface extending upwardly and rearwardly from said supporting surface at an acute angle of at least twenty degrees with the reading plane, an upper surface extending forwardly at an acute angle of at least fifteen degrees with the reading plane, said upper surface being formed with an integral lens surface for magnifying the reading matter, and an obturating surface extending from the supporting surface to the upper surface.

3. A prismatic reading lens comprising an inverted prism having a bottom supporting face for resting on a substantially horizontal reading plane, an inclined face extending upwardly and rearwardly from the bottom face over the reading matter to refract rays therefrom, an upper face extending forwardly and downwardly from said inclined face, said upper face being provided with a lens for magnifying the reading matter, and an obturating face extending from the bottom face to the upper face.

4. A fixed focus reading lens comprising a supporting surface for resting on a reading plane, a planar surface extending upwardly and rearwardly from said supporting surface over the reading matter to refract rays therefrom, a curved upper magnifying surface extending downwardly and forwardly from said planar surface, an obturating surface extending from the supporting surface to the upper surface, and additional support means to assist said supporting surface in maintaining the reading lens in stable relationship to the reading plane.

5. A reading lens comprising a supporting surface for resting on a reading plane, a planar surface extending upwardly and rearwardly from said supporting surface over the reading matter to refract rays therefrom, a curved upper magnifying surface extending downwardly and forwardly from said. planar surface, an obturating surface extending from the supporting surface to the upper surface and means integrally formed at an end of said supporting surface forming a continuation thereof rearwardly to assist in supporting the lens from the reading plane.

6. A reading lens comprising a supporting surface elongated from side to side, adapted to rest on a reading plane forward of the reading matter, a planar surface extending upwardly and rearwardly from the rear edge of the supporting surface for refracting light rays received from the reading matter, a second obturating surface extending upwardly from the forward edge of said supporting surface, a curved upper surface extending downwardly and forwardly between said two upwardly directed surfaces for magnifying the reading matter, and triangular lugs formed at the sides of said supporting surface in continuation thereof rearwardly over the reading matter and extending upwardly to said planar surface to prevent tilting of the lens with respect to the read- Number ing plane. 1,701,028

GEORGE M. CRESSATY. 1,908,157 REFERENCES CITED 3 83%? The following references are of record in the 5 2:340:421 file of this patent:

UNITED STATES PATENTS Number Number Name Date 10 204,288 1,600,808 Dukehart Sept. 21, 1926 223 35 1,671,272 Buckingham May 29, 1928 SEAKCH ROOM Name Date Buckingham Feb. 5, 1929 Walsoe May 9, 1933 Stanley July 6, 1937 Bock July 13, 1939 Obrist Feb. 1, 1944 FOREIGN PATENTS Country Date Great Britain Sept. 27, 1923 Great Britain Feb. 5, 1925