US2186570A - Television reproducer - Google Patents

Description

1940- J. c. BATCHELOR 2,186,570

TELEVISION REPRODUGER Filed Aug. 15, 1957 um"; mumn ATTORNEY fig. 5 BY wgzww Patented Jan. 9, 1940 2,186,570 TELEVISION REPRODUCER I 7 John C. Batchelor, Hastings oil-Hudson, N. Y.

Application August 13, 1937, Serial N0.. 15 8,867

(Cl. 178-7-5) k h ventional direction. Thus, the proper lateral 9 Claims.

My invention relates to improvements in television apparatus, and, more particularly, to a television receiving apparatus wherein a cathode ray tube or like means is utilized for the production of a relatively small, brilliant image adapted to be projected to a larger, less brilliant image under various conditions of projection.

It is customary in the television art to provide radio receiving means for intercepting broadcast television signals, including a cathode 'ray tube with associated control circuits whereby, under the influence of rhythmical deflection and intensity control, images can be reproduced in accordance with the intercepted signals.

In certain of such receiving apparatus, relatively large cathode ray tubes have been used whereby an image can be reproduced of sufiicient size and brilliancy to have entertainment value when viewed directly in a normally illuminated room. I

More recently, cathode ray tubes of a relatively small size, and capable of producing images of relatively high intrinsic brilliancy, have been produced wherefrom images can be projected to sizes larger than those produced upon the earlier direct-vision tubes. Any .of the newer, projection-type cathode ray tubes for example, are applicable in apparatus embodying my invention.

It has been customary in the past to provide television sets containing such projection-type" cathode ray tubes, these being disposed horizontally within a cabinet provided with a projection lens at or near the front face of'the cabinet, whereby images from the tube can be projected to a point external to the cabinet upon a reflection-type screen to produce enlarged images. Alternately, sets have been provided in the past comprising such a cathode ray tube disposed at or near the back of a receiving cabinet, and in cooperation with a ground glass screen on the front face of the cabinet, images have been projected by a projection lens interposed between the tube and the ground-glass transmission-type screen which can be viewed from a point external to the cabinet.

It may be seen, however, that, in the event that it is desired to use a common set for the projection of images at will to either a reflectiontype or transmissiomtype screen, with the set properly adjusted for one condition of projection, the images produced on the other screen will be optically inverted in a horizontal direction so that, for example, printed matter will appear readable from right to left instead of inthe conaspect ofthe image is not"maintained in the two conditions of projection. Under existing methods, it would be necessary to resort to expensive and cumbersome optical apparatus to accomplish -'a reinversion of the image in a lateral direction, and this condition, therefore, becomes a serious difiiculty in providing a satisfactory combination receiver, 10

i In View of the desirability of eifecting sucha combination without the shortcoming here outlined, itis an object of my invention to provide an improved television receiving apparatus adapted to produce television images alternately 16 upon a transmission-type screen mounted in the front surface of the receiving cabinet, or upon a reflection-type screen disposed external to and at a substantial distance from the cabinet of the receiver. V 20 This and other objects-will be apparent from the following description of an embodiment of myinvention. v v

In accordance with my invention, I have provided a cabinet containing television image'- 26 reproducing means including a cathode ray tube of the projection type, a transmission-type screen upon the face of the cabinet, a reflection-type screen external to the cabinet, means for projecting an image from the cathode ray tube selectively upon either of the screens, and means 1 cooperating with certain components of the apparatus to invert the image on the cathode ray tube in a horizontal direction-when one of the screens is removed from service and the other is employed. l For the purpose of illustrating my invention, an embodiment thereof is shown in the drawing, wherein- I Figure 1 is a simplified, elevational view, partly in section, of a television receiver constructed ,0 and operating in accordance with my invention; Figure '2 is an enlarged, detail, sectional view taken from Figure 1, showing a modification;

Figure '3 is a plan View of Figure 2 showing another modification;

I Figure 4 is an enlarged, detail, fragmentary View taken from. Figure 1; and

Figure 5 is an enlarged, detail view looking upwardly on line 5-5 in Figure 1, and showing diagrammatically part of the electrical control circuit.

Referring now to Figure 1, the reference numeral B designates a cabinet of any suitable type containing a shelf l on which is mounted radio receiving apparatus 8 provided with c'ontrols 9 and ID on the front of the cabinet for adjusting the apparatus to receive selectively any desired transmitted signal.

The output of the receiving apparatus 8 is conducted by a cable II to control apparatus I2 including, suitable amplifiers, synchronizing devices, power-supply units and the like of any of the various types well-known in the art and adapted to produce on the associated cathode ray tube I3 an imagein accordance with the signals received by the receiving apparatus 8.

Preferably in association with the shelf I, is an optical system 14 comprising a long-focus lens I and a short-focus lens 2. A control knob 5 is provided on the front of the cabinet '6 which communicates by means of a shaft I6 with the optical system I4. The lens I. is focused by rotation of the knob I5. The lenses 1! and 2 operate independently of each other and are movable bodily together, to selectively associate them with the cathode ray tube I3, by moving the control knob I5 in a direction along the axis of the shaft I6.

A mirror I'I, preferably of the front-surface type, is supported. within the cabinet in the region which is both directly over the cathode ray tube I3 and the operating lens unit, and

directly behind a screen I8 provided on the front of the cabinet 6.

' The screen I8 consists preferably of a relatively thin-sheet of Celluloid of the slow-burning type and roughened'on the interior surface by sand-blasting, or by grinding with an abrasive powder or other suitable means. The screen I8 is mounted in a suitable frame It which is pivotally supported in the front surface of the cabinet 6 by hinges 2|. A knob 22 is provided whereby the frame I9 can be swung from a position coplanar with the front surface of the cabinet 6 to the position shown within the cabinet,

in which latter position it'is held by a spring catch 23. A ball-and-socket latch 24 is provided to retain the frame ISin the vertical position co-planar with the front surface of the cabinet when desired. A double-pole double-throw switch 5 is provided on the front of the cabinet at a point adjacent the frame It and is 50 disposed as to be actuated by an arm 25 upon movement of the frame I9. The switch 5 is connected by means of a four-wire, shielded cable 26 to operate as a polarity-reversing switch between the horizontaldeflecting wave generator in the control apparatus I2 and the electro-magnetic'deflecting coils 21 associated with the cathode ray tube I3.

The operation of my invention is as follows. A radiant energy signal is intercepted, amplified and detected by the radio receiving apparatus 8 and the resultant signal is communicated by the cable II to the control apparatus I 2 where it is further amplified if desired and all or part of the signal is then utilized to control the input to the deflecting coils 21. The signal is, moreover, ap-

plied to the control element in the cathode ray tube I3 and, by the cooperation of the intensity and position control applied to the tube I3, an

image is reproduced on the tube I3 in accordance with the signals intercepted by the receiving apparatus 8.

I In the condition of operation of the apparatus of Figure 1 when the screen It is co-planar with the front surface of the cabinet 29 and the lens I is associated with the cathode ray tube I3, an image will be projected from the tube I3 by way of the mirror II to the screen I8 on the front of the cabinet 6. Thus, a relatively small image appears upon the screen It clearly visible from a point directly before this screen and looking in the direction toward the receiving apparatus, and may have sufficient brilliancy to be clearly visible in a fully illuminated room.

In another condition of operation, with the screen adjusted as described above and the lens 2 associated with the cathode ray tube I3, because of the shorter focus of the lens 2, an image of the image on the cathode ray tube I3 is projected by way of the mirror II to the screen I8 which image is appreciably larger than the image non-operating position in the upper part of the cabinet 6. As shown in Figures 1 and 4, upon .this movement of the screen I8, the arm 25 operates the switch 5 to reverse the polarity of the deflecting voltage applied to the deflecting coils 2i, so that the image reproduced upon the cathode ray. tube I3 will be laterally inverted. A reflection-type screen 28 lies substantially upon the horizontal portion of the optical axis of the system comprising the cathode ray tube I3, the lens I and the mirror I'l, so that in this third condition of operation, an image will be projected by that optical system upon the screen 28. The image produced upon the screen 28 will appear in proper lateral aspect when viewed by an observer from a position between the cabinet 6 and the screen 28, in a direction away from the receiving apparatus. Thus, there is provided automatic means whereby, for example, printing maybe maintained easilyreadable regardless of whether atransmission-type or reflectiontype screen is used in my receiving apparatus.

In Figure 2 is shown in somewhat greater dey tail the optical system with a modified form of control apparatus whereby proper lateral aspect is maintained under various conditions of projection in my invention. Carried on the shelf 1 and guided by rails 30 is a carrying plate 3i on which are mounted the lenses I and 2 by means of an adapter 32. The lens 2 is fixedly mounted in the adapter 32 whereby a suitable condition of focus is maintained.

The lens I is carried in an opening in the adapter 32 and is held from radial motion by a key3 i on the tube 35 of this lens and in axially slideable relation to a key-way 36 in-theadapter 32. An adjustable screw-stop 31 is provided to limit the possible upward travel of the lens I in the adapter 32. and a second adjustable screwtop 38 is provided to limit the possible downward extent of travel. A gear rack 39 provided upon the surface of the lens tube 35 and an associated pinion 40 on a shaft M provide for vertical positioning of the lens I. A universal joint 62 connects the shaft 4| to the shaft I5 for rotation by the latter. Suitable friction may be introduced in any appropriate bearing or by other means to overcome the downward effect of gravity upon the lens I, but in a preferred embodiment of my invention there is a sufficiently close fit between the lens tube 35 and the adapter 32 to prevent downward motion of the lens I except upon the application of a force of rotation to the knob I5. I

' In the embodiment of my invention as shown in Figure 2, I substitute for the switch 5 in Figures 1 and 4 a double-pole double-throw polarity-reversing switch 4 mounted on the plate 3I and having a toggle 13 adapted to cooperate with an extension 44 attached to the lens tube 35,

whereby the switch 4 is operated when the lens I adapted to cooperate with a key-way 41 in a bearing 48 in a manner adapted to prevent rotational motion of the shaft it when it is pulled outward to render the lens 2 coaxial with the cathode ray tube I3.

Thus, in operation, when it is desired to use the transmission-type screen I8 and. either of the lenses I and 2, it is necessary first to rotate the knob I5 to a position wherein the lens I is in focus for this condition, which will be its uppermost position as determined by the stop 31, and the key 46 will then he in a position wherein it may engage the key-way t! when an outwardly axial force is applied to the knob I5 if it is desired to use the lens 2. In this manner the correct lateral aspect is ensured when the lens I or the lens 2 is to be associated with the projection system because the switch 4 is, under this condition, in the correct position for producing a normal image on the transmission-type screen I8.

Thus, in this embodiment of my invention, there is provided switching means in association with the optical system of my apparatus whereby the proper lateral aspect is maintained in a projected image under the various conditions of operation encountered in my apparatus.

Figure 3 represents a plan view of a portion of an optical system similar to that shown in Figure 2, except that the switching control means have been somewhat modified. The carrying plate SI is shown, carried on the shelf I and guided by the rails 36, and by axial motion applied through the knob I5 and the shaft IS, the lenses I and 2 can be positioned with their axes selectively coincident with the axis of the cathode ray tube I3. In this embodiment it is contemplated that the lens 2 will be used only in connection with the transmission-type screen, and the lens I be used only in connection with the reflection-type screen, and, consequently, the reversing switch 3, corresponding to and serving the same purpose as the switches 5 and I in Figures 1 and. 2, may be operated by the influence of the motion which selectively associates those lenses with the cathode ray tube I3. Thus, the switch 3 is mounted on the shelf 7 in a manner such that the toggle #9 will be operated by an extension 50 carried on the plate 3|, and the position of that switch will be determined according to which of the lenses 5 and 2 is associated with the cathode ray tube I3. A four-wire cable 5i is provided for the connections between the switch 3 and is connected to the deflection apparatus as in previous embodiments of my invention to effect the apare shown.

propriate reversal or inversion of the lateral aspect of the image.

A preferred form of the screen-actuated embodiment of my invention is more clearly shown in Figure 4 wherein the arm 25 carried on the frame I9 is adapted to cooperate with the toggle 52 of the switch 5 to operate that switch when the frame I9 is moved to a position within the cabinet. In this embodiment the switch 5 is mounted within a switch box 53. A slotted guard plate Ed is provided whereby only a relatively small portion of the top of the arm 25 is allowed access to the toggle 52, thereby preventing manual operation of the switch 5.

- In Figure 5 is shown in more detail the defleeting system associated with my apparatus, and. the circuit connections of the deflecting-energy generators, switching means and deflecting coils In Figure 5 a magnetic core 55 is provided with four inwardly extending pole pieces 5%, two of which carry the vertical deflecting coils 5i and the other two of which carry the horizontal deflecting coils 21. The vertical deflecting coils 5i are permanently connected to the vertical-deflection generator 59, whereas the horizontal deflecting coils 27 are connected to the horizontal-deflection generator Iii) through a pofsrity-reversing switch ilI which corresponds to the switches 3, 4 or 5, and is adapted to selectively reverse the polarity with which the output of the generator 66 is applied to the coils 21 in series. Thus, the vertical image aspect is permanently fixed by the permanent connection between the generator 5% and the coils 57, but the lateral aspect of the reproduced image is selecvely changeable by means of the switch BI interposed between the generator to and the coils 21 in series.

It should be clearly understood that various modifications are possible within the scope of my invention. For example, in the embodiment of Figure l, the switch 5 may be mounted at or about the hinges 2| of the frame I9 and operated by the upper member of the frame I9. Similarly, in the embodiments shown in Figures 2 and 3, various mechanical configurations may be employed to accomplish the appropriate reversal or inversion in accordance with my invention.

Moreover, although I have shown three distinct modes of operation of my invention, namely, a small image projected on a transmission screen, a large image projected on a transmission screen, a large image projected on a transmission tion screen, it should be understood that more or fewer conditions of operation are possible within the scope of my invention and that suitable lens turrets may be employed to make possible more conditions of operation just as one lens may be eliminated in those embodiments shown when fewer conditions of. operation are desired.

I claim as my invention:

1. In television receiving apparatus, an imagereproducer of the projection type and being in the form of a cathode ray tube, means for deflecting the cathode ray, means for reversing the lateral aspect of the image on said image-reproducer, and a single control means for controlling said reversing means and simultaneously adapting apparatus selectively for projection of the reproducer of the projection type and being in the form of a cathode ray tube, means for defleeting the cathode ray, switch means for reversing the lateral aspect of the image on said image-reproducer, and movable means for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus,

said switch means being disposed for actuation by said movable means upon movement of the latter for the purpose set forth.

3. In television receiving apparatus, an imagereproducer of the projection type, means for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, and means for inverting the lateral aspect of the projected image and actuated by said first-named means upon operation of the latter for the purpose set forth.

4.. In television receiving apparatus, an imagereproducer of the projection type and being in the form of a cathode ray tube, means for defleeting the cathode ray, switch means for reversing the polarity of said ray-deflecting means to reverse the lateral aspect of the image on said image-reproducer, and means in the form of a movable screen for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, said switch means being disposed for actuation by said screen upon movement of the latter for the purpose set forth.

5. In television receiving apparatus, an imagef reproducer of the projection type, means in the form of a movable screen for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, and means for inverting the lateral aspect of the projected image and actuated by said screen upon movement of the latter for the purpose set forth.

6. In television receiving apparatus, an imagereproducer of the projection type and being in the form of a cathode ray tube, means for defleeting the cathode ray, switch means for reversing the polarity of said ray-deflecting means to reverse the lateral aspect of the image on said image-reproducer, and means including an adjustable lens for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, said switch means being disposed for actuation by said lens upon adjustment of the latter for the purpose set forth.

'7. In television receiving apparatus, an imagereproducer of the projection type, means including an adjustable lens for adapting said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, and means for inverting the lateral aspect of the projected image and actuated by said lens upon adjustment of the latter for the purpose set forth.

8. In television receiving apparatus, an imagereproducer of the projection type and being in the form of a cathode ray tube, means for defleeting the cathode ray, switch means for reversing the polarity of said ray-deflecting means to reverse the lateral aspect of the image on said image-reproducer, and means including lens units operating independently of each other and movable bodily together to adapt said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, said switch means being disposed for actuation upon movement of said lens' units for the purpose set forth.

9. In television receiving apparatus, an imagereproducer of the projection type, means including lens units operating independently of each other and movable bodily together to adapt said apparatus selectively for projection of the image such that it may be viewed in a direction either toward or away from said apparatus, and means for inverting the lateral aspect of the projected image and actuated upon movement of said lens units for the purpose set forth.

JOHN C. BATC'I-LELOR.

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