US2950662A - Photocomposing apparatus - Google Patents

Description

1960 R. A. HIGONNET ET AL 2,950,662

PHOTOCOMPOSING APPARATUS 2 Sheets-Sheet 1 Original Filed June 4, 1951 Fig.

Allg- 1960 R. A. HIGONNET ET AL 2,950,662

PHOTOCOMPOSING APPARATUS 2 Sheets-Sheet 2 Original Filed June 4, 1951 Fig .4

INVENTORS T E W S W V R E OY N mwo u H M m AM M E B N U R L W g ates 'atent hee PHOTOCOMPOSING APPARATUS Rene A. Higonnet, Cambridge, and Louis M. Moyroud,

West Medford, Mass, assignors to Graphic Arts Research Foundation, Inc., Cambridge, Mass., a corporation of Delaware Original application June 4, 1951, Ser. No. 229,804, new Patent No. 2,787,199, dated Apr. 2, 1957. Divided and this application June 8, 1956, Ser. No. 590,305

Claims priority, application France June 6, 1950 4 Claims. (Cl. 954.5)'

The present invention relates to improvements in photographic type composing machines, and more particularly to improvements in control means for selectively photographing each character in a line of type. This application is a division of our copending application Serial No. 229,804, filed June 4, 1951, now Patent No. 2,787,199. The invention is concerned especially with improvements in the photocomposing apparatus shown in our prior applications, as for example, Serial No. 770,320, filed August 23, 1947, now, Patent No.

2,790,362 and Serial No. 187,752, filed September 30,

1950, the latter having been issued as Patent No. 2,664,986.

The invention will be described in relation to the embodiments shown in the accompanying drawings in which:

Fig. 1 is a diagram showing the construction of a control mechanism for the manufacture of a character disk;

Fig. 2 is a diagram of a decoder utilizing magnetic means;

Fig. 3 shows how the matrix characters are arranged with respect to the optical axis of the photographic lens; and

Fig. 4 shows how characters of diflerent point size are obtained from the same matrices.

In our copending application Serial No. 770,320, we have described a so-called fine or precise control apparatus utilizing photo-electric means associated with the character disc and tending to activate the flash circuit upon the passage of each and every character through projection position. While this precise control circuit thus tends to activate the circuit for each and every character, it is prevented from doing so by a so-called rough control circuit which in combination with the register, keeps the flash control circuit open until a particular selected character comes into photographing position.

According to the present invention, the fine or precise control circuit comprises a magnetic recording device which is shown in Figs. 1 and 2.

Referring to Fig. 1, the master character disc is shown in and may be made of a glass photographic plate. On the periphery of the disc at 12, an extremely thin layer of magnetic particles has been deposited, for example by means of a binder resin. These particles may be of magnetic alloy or of any other suitable magnetic substance such as iron oxide. In front of this magnetic ring, and at a short distance from it, is a recording coil 14 of the type used in the magnetic voice recorders. The matrices of the characters are drawn at a large scale and held in position on a mounting plate 16 by means of, for example, two registering rods 18. A lens 20 makes an image 21 of the character 22 on the photo graphically sensitized surface of the disc. At the same time as the photograph of the character is made, an electrical impulse is sent into coil 14 by an appropriate circuit shown diagrammatically at 24. This magnet-izes the ring 12 locally at a point having an exact angular relationship with the photographic image 21. The same procedure is carried out for each character of the font.

After having been developed, the disc is used in a mounting similar to the one shown in Fig. 2 and comprising a reading coil 26, a discharge tube 28, a lens 30 and the film 32. The lens is mounted in a turret 34, to be referred to later. The disc spins continuously and the coil generates an impulse each time a character passes in photographing position. This impulse, amplified by an amplifier 36, is normally inoperative, being stopped by a gating circuit 38, for example, a vacuum tube appropriately biased. The gating circuit is made conductive by the decoder '40 when the selected character passes in photographing position. The impulse, associated with the selected characters and generated by the passage of a magnetized section of ring 12 opposite coil 26, is then amplified and directed onto the discharge tube 28 which it primes. The supply circuit of the discharge tube is shown schematically in 44.

The decoder 40, instead of being as described in the above-mentioned application, preferably uses magnetic means as shown in Fig. 2. The brushes are replaced by reading coils 50 to 57 co-operating with magnetic bands 50' to 57 on the decoder drum 40. On these magnetic bands are registered signals corresponding to the different code combinations. The reading coils are put in or out of the circuit by switches 60 to 67, respectively, which are controlled by the register. When the magnetic bands of the decoder rotate, a moment arrives, according to the code of the selected character, when there is no signal. The gating circuit 38 then lets pass the positioning impulse generated by coil 26. The details of the register are not shown, nor is the specific form of the amplifier and gating circuit, since said parts will be clear to those skilled in the art, after reference to said application.

The magnetic bands may be of various types. For instance, it is possible to use a layer of magnetic substances and to record on this magnetic layer the different code signals. The code signals can be directly registered or can modulate a high frequency current. In the latter case, a detector is placed at the input of the gating circuit 38.

One of the main advantages of photocomposition rests in the possibility of obtaining several point sizes starting from a single character matrix. This result is obtained by enlarging or reducing photographically. To this end, the lens turret 34 in Fig. 2 is provided with a plurality of lenses of different focal lengths, one shown at 30 and another at 130. Any number of diiterent lenses may be provided. The turret is rotatable about an axis 132 to bring the optical axis of any desired lens into coincidence with the projection axis.

However, it is well recognized that best results cannot be generally obtained when using exactly similar characters. In other words, the drawing of a character of small point size cannot be obtained by the simple reduction of a character of larger size. The typecasters have realized the difliculty, and the creation of a family of characters of point sizes 5 to 16 points calls for generally 2 or 3 different drawings serving as a basis for punchcutting.

This is very apparent if the same letter taken in alphabets of diiferent point size is enlarged to the same height h (Fig. 4). In this figure is shown the result of taking letter H of point size 6 (lowest diagram),

- =3 width to characters of small point size with respect to their height. In the same manner, the thickness of the legs is also increased. This rule originated from practice. The widening of the characters does not vary proportionally to the point size but should increase as the point size is reduced.

According to features of the present invention, simple means are used to satisfy the requirements arising from the rules mentioned above. This is obtained by a combination of mechanical and optical means. It will be explained in relation to the process used for making the matrices.

The matrix discs are made by photographic means. The characters are drawn at a large scale on plates or paper 16 (Fig. 1).

Figure 3 shows how the optical axis is located with respect to the matrix character. The position of the character is defined by two axes XX and YY. Axis XX is the base line and the axis YY defines the left hand approach. If the characters are photographed in the order of they align on the left hand approach axis line YY. In order to keep the characters in correct position with respect to the left hand margin when the magnification is changed, it is necessary that the optical axis of the projecting lens 2%, Fig. 1 intersect the left hand axis YY. If this is not the case when the lens is changed for obtaining characters of larger dimensions, the enlarged character will overlap the left hand margin. The same applies for the alignment defined by axis XX, which the optical axis of the lens must also intersect. It follows that the intersection of axes XX and YY is the point where the optical axis of the projecting lens must intersect the character at the time when the flash of light takes place.

It follows that the characters, when enlarged or reduced by photographic methods always fall in the same upper right quadrant except for letters whose descenders fall into the quadrant immediately below.

In order to produce the changes indicated in Fig. 4 from a single font of characters, the invention provides for optical distortion during transcription. This is most conveniently afforded by cylindrical lenses. Thus, in Fig. 2, there is associated with the lens 130 a cylindrical lens 134. As an example, for the characters of Fig. 4, the spherical lens 3t} would be used for the large pointsize (top diagram) and the combined lenses 130 and 134 for the small point size (bottom diagram), the cylindrical axis being vertical when the lens combination 130, 134 is in projection position. This gives the spreading effect for the smaller point size.

The lenses 130 and 134- may be spaced along the optical axes according to suitable principles of lens design. If desired, a single sphero-cylindrical lens (or lens system) may be used. It will be understood that the spread is relatively small, and that adequate depth of field is attained. The various lens systems provided on the turret will be constr'ucted'for the desired magnification and spread of the characters.

The characters are projected one by one'on a film in order to compose words. To space the characters the film (or a reflecting surface such as a prism) is advanced after the projection of each character. We shall assume here that the film is advanced and that these advances or steps shall be referred to as the distance s by which the film must be advanced after each character is projected. The maximum height occupied by the characters including the small margin left above and below to space the lines without interference between ascending and descending characters will be called point size c. The usual point sizes used in typographic work are 5, 6, 7, 8, 9,10, ll, 12 and 14 points. As explained above, changing point sizes requires changing the lenses.

According to the present invention, the mechanism for advancing the film provides advances which are not proportional to the point size. -If .this was not done, the

larger the point size the more the characters would be spaced apart one from the other because of the increase in surface, as shown by the hatched portions of Fig. 4.

Figure 5 of our application Serial No. 187,752 shows a mechanism for controlling the film advance. If the characters were exactly proportional in the different sizes, a displacement of the driving racks by a number of teeth equal to the point size could be used; for example, the rack would be displaced by 6 teeth for the point size 6, 10 teeth for the point size 10, etc. According to one feature of the invention, this proportionality is not kept, thus permitting in a simple fashion a variation in the advances corresponding to nonproportional variations of width of characters in different point sizes.

Let us assume that 14 is the largest point size desired from the machine; the procedure is as follows. The drawings of the characters are made so that they have the correct proportions for point size 14 and their advance is made to correspond to a displacement of 14 teeth of the control rack. These master characters are used for making the matrix disc. On the other hand, the advances for the other point sizes are made equal to the corresponding number of teeth plus one, for example. The resulting (or corrected) advances obtained are given 1n the table below:

Advances Percent In- Propor- Corrected crease in Point Size tional by the Ad- Advance of Advances dition of Character One Tooth Teeth Teeth 5 (5 6 7 7 8 8 9 9 1O 1O 11 ll 12 12 13 14 14 According to this table, the ratio of the difference between the corrected and the proportional advance for a given point size to the proportional advance is greater for small point sizes, which conforms with the desired results. For example, between point size 6 and point size 5 the increase is 3% but only /2% between point sizes 12 and 11.

The bold characters generally require a greater advance than the corresponding roman characters. This may be obtained by increasing the displacement of the control rack by alvancing it n supplementary teeth. The increase of advance a is then in which 0 represents the proportional advance (or for example the point size). The advantage of such a system, for a given point size is the increase of the ad vance proportional to the width of the'character. The real advance, that is the space reserved for a character on the film is given by the equation s=u(n+d) where u is the number of elementary units contained in the character, this quantity characterizing the relative width of the character (for example, i=5 units; =10 units; 14/;13 units; m=l5 units; etc.) independently of the point size. "n represents the number of additional teeth by which the control 'rack is advanced and d represents the proportional advance'or the point size, corrected as indicated by the table. By way of example, consider characters 2' and m composed in point size 11 (d=l2).' For roman characters, taking n l, for i we have s=5(l-|-l2)=65 elementary units of width. For a roman m we have s=15(l+12)=l95 elementary width units. On the other hand, for bold characters, taking n=2, we have for z 70 andfor m s=15(2+l2) :210. !In comparing these results with those given above we find that the increase in advance for i is 5 supplementary units while it is 15 units for m.

It is clear that, although the given examples refer only to the increase in the proportional advance for smaller point size or hold characters, a reverse distortion can be chosen, for example for obtaining condensed characters. In the same way the ordinary advance used for roman characters can be reduced for italic characters by decreasing the extent of the movement of the control rack.

Although the present invention has been shown and described in relation to particular embodiments, it is clear that these embodiments can be modified without departing from the field of the invention.

Having thus described the invention, we claim:

1. In a photocomposing machine, the combination of a rotatable character carrier having a font of characters and a band of magnetic material, said band having local areas of magnetization each in precise relationship to a particular character of the font, continuously rotating mechanism for moving the characters successively through a projection position, a reading coil in fixed position relative to said projection position to generate an impulse produced by each of said local areas of magnetization at the precise instant when the corresponding character passes through said projection position, a support for a sensitized sheet, a discharge tube to project a character in said projection position on to said sheet, and means including said reading coil to energize the discharge tube.

2. In a photocomposing machine, the combination of code means to represent successively the selected characters in a line of type, a rotatable character carrier having a font of characters and a band of magnetic material, said band having local areas of magnetization each in precise relationship to a particular character of the font, continuously rotating mechanism for moving the characters successively through a projection position, a reading coil in fixed position relative to said projection position to generate an impulse produced by each of said local areas of magnetization at the precise instant when the corresponding character passes through said projection position, a support for a sensitized sheet, a discharge tube to project a character in said projection position on to said sheet, and means including said code means and said reading coil to energize the discharge tube.

3 In a photocomposing machine, the combination of a rigid, continuously rotatable carrier for the characters to be photographed, said carrier having a band of magnetic material with local areas of magnetization each in precise spatial relation to a corresponding character, mechanism for rotating the carrier to cause the characters to pass successively through a projection position, a support for a sensitized sheet, an intermittent flash device in position to illuminate a character in said position by a light flash of short duration, and means to energize the flash device including a register in which information corresponding to the selected characters in a line is stored, reading means including a circuit conditioned by said information in the register, a rough control synchronized with the support and conditioned by the reading means to be operative during an interval in which only a selected character is in said position, and impulse means associated with said band and operative at the precise moment when each and every character is in said position, whereby the flash device is energized only by the joint action of the reading means, the rough control and said impulse means.

4. In a photocomposing machine, the combination of a support bearing the characters to be photographed and magnetic material, said material being magnetized in local areas each in precise spatial relation to a corresponding character, mechanism for moving the support continuously relative to a projection position, the characters passing consecutively through said position, a support for a sensitized sheet, a device in position to project the image of a character in said position on to said sheet, and means to operate said device when a selected character is in said position including a reading coil in precise spatial relation to said position and in position to cause an impulse to be produced by passage of the corresponding magnetized area adjacent to said coil.

References Cited in the file of this patent UNITED STATES PATENTS 2,617,705 Coornbs Nov. 11, 1952 2,646,733 Ackerman July 28, 1953 2,713,456 Reynolds July 19, 1955 2,714,842 Hooven Aug. 9, 1955 2,714,843 Hooven Aug. 9, 1955 2,715,862 'Moyroud Aug. 23, 1955

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