FR2505117A1 - VIDEO PROJECTION APPARATUS - Google Patents

Abstract

A. VIDEO PROJECTION DEVICE. B. APPARATUS CHARACTERIZED IN THAT IT CONTAINS A CASE IN WHICH ARE HOUSED THE PROJECTION LENSES AND THE CATHODIC RADIUS TUBES, A MIRROR ON THE FRONT OF THE CASE, A CONTROL SOURCE, TWO CONTROL SECTIONS COMMANDED SIMULTANEOUSLY BY THE SOURCE OF CONTROL, A PAIR OF EXTENSION-CONTRACTION MECHANISM CONTROLLED BY THE CONTROL SECTIONS, ONE SHAFT COUPLING THE TWO CONTROL SECTIONS TO ONE ANOTHER. C. THE INVENTION APPLIES IN PARTICULAR TO THE PROJECTION OF VIDEO IMAGES ON A LARGE SCREEN.

Description

1. The invention relates to a video projection apparatus in which

  a mirror reflecting and intended to project on a screen the light emitted by cathode ray tubes, can be automatically advanced from a front part of a chassis-shaped box constituting

  killing the device and removed in this front part of the chassis.

  It has been developed to date, a video projection device that projects a video image of a set

  on a screen to obtain a large-scale image.

  However, the video projection apparatus with which a reflecting mirror can be, by remote control, pro Throw forward from a front portion of a box-shaped frame in which are housed the projection lenses

  and cathode ray tubes, has not yet been developed.

  Nevertheless, it is undesirable to adopt a structure in which a reflecting mirror is assembled while being in

  protruding from the front of the chassis because such a structure

  ture implies increased dimensions for the whole of the

  In addition, it is not desirable to adopt a structure

  in which a reflecting mirror is pulled out by an opera-

  Manual operation of the front part of the chassis when necessary, because this operation is tedious As a result, it was desired to produce the video projection apparatus

  thanks to which a reflecting mirror can be projected by

  remotely only at the time of use in a forward direction of the front of a frame, in a position compatible with an optical system to provide

  projection from cathode ray tube on a screen.

  An object of the present invention is to create

  a video projection apparatus with which a reflecting mirror

  on the front of a box-shaped frame,

  can be ordered to be transferred to a predefined position

  completed in front of the chassis by the action of a source of

  and also be ordered to be housed in a posi-

  predetermined pattern inside the chassis.

  Another object of the present invention is to create a video projection apparatus in which a reflecting mirror can be moved while maintaining this mirror in a correct position with respect to an optical system

video.

  2. Another object of the invention is to create a video projection apparatus in which there is provided a coupling shaft coupling two control sections, without it being

  necessary to provide for this purpose a special space.

  The invention will be described in more detail with reference to the accompanying drawings, in which:

  FIG. 1 is a perspective view from

  In an embodiment of the video projection apparatus according to the present invention, FIG. 2 is an enlarged side view with partial cutaway showing the neighborhood

  control sections and extension-contraction mechanisms

tiont

  FIG. 3 is a partial sectional view of

  the individual control sections coupled to a coupling shaft,

  Figure 4 is a fragmentary sectional view of

  the expandable tubes, the third expandable tube being in extension, Figure 5 is a longitudinal section

  showing a control section in a state prior to the operation

  of rotating an operating lever, Fig. 6 is a longitudinal section showing the control section in a state after the operation

  of turning the operating lever.

  FIG. 1 is a perspective view

  feeling an embodiment of the projection apparatus in accordance with

the present invention.

  As shown in Figure 1, a chassis 1

  in the form of a casing houses a plurality of projection lenses

  2 and 3 corresponding cathode ray tubes, while a reflecting mirror 5 is provided on the front part

4 of the chassis 1.

  Inside the frame 1 are provided a

  a control source 6, a first and a second control section 7 and 8 controlled as a

  pair by the control motor 6, extension mechanisms-

  contraction 9 and 10 ordered as a pair for the purpose of ex-

  tension and contraction by the control sections

  7 and 8, and a coupling shaft 11 provided between the ends

  3.- Rear mounts 3 to individual cathode ray tubes and the rear end of the frame la, and coupling the control sections 7 and 8 The extension mechanisms -contraction 9 and

  are ordered as a pair for expansion and con-

  traction in synchronism with each other by the shaft

  coupling 11 controlled by the control sections 7 and 8.

  The control shaft 12 of the control motor 6, as shown in FIGS. 2 and 3, comprises a gear

  worm 14 rotatably mounted inside an outer casing

  The worm gear 14 meshes with a worm wheel 15 A disc-shaped clutch plate 16 is provided on the same shaft as the wheel 15 This clutch plate 16 is attached to a drive shaft 17 The drive shaft 17 is rotatably mounted within the outer casing 13 between the plate

  clutch 16 and the worm wheel 15, a mechanism is provided for

  anti-overcurrent 18 which serves to pocket a state of overload

  to occur when a load exceeds a predetermined value

  In the present realization, at the moment

  of the normal driving contact, the plates 18a and 18b

  5, respectively, are provided on the clutch plate 16 and the worm wheel 15. When a load exceeding a predetermined value is applied to the aforementioned worm wheel 15, the plates 18a and 18b are separated. thanks to which the ali

  power supply of the control motor 6 is disconnected.

  A small gear 19 has been integrally formed with the drive shaft 17, and a section 19a of this small gear 19 meshes with a section 20a of a large gear 20 This large gear 20 is rotatably mounted on a

  shaft 21 attached to external casing 13.

  Hard the side of the chassis I opposed to this first

  first control section 7 above, fixed on the frame 1,

  the second control section 8 driven by the drive motor

  6 is attached to the frame 1 The second section of the

  Mande 8 is of identical construction to that of the first control section 7, except that the worm gear 14 is rotated by the motor 6, the worm wheel 15, the overload mechanism 18 and the clutch plate 16, are not provided More specifically, a drive shaft 23 rotatably mounted inside the outer casing 22 of the 4.- second control section 8, is provided with a small gear 24 and a section 24a of this gear 24 meshes with a section 25a of a large gear 25 This large gear 25 is rotatably mounted on a shaft 26 fixed to the outer casing 22. The two gear mechanisms 25 extension-contraction 9 and 10, provided in parallel between the first and second control sections 7 and 8, each consist of a first, a second and a third extensible tubes 27, 28 and 29, respectively constituted in this embodiment, d a cylinder

  large diameter, medium diameter and small diameter.

  A control band 30 of the expandable tubes 27, 28 and 29 extends through the second and third expandable tubes 28 and 29, so that it can be controlled to flow through the second and third expandable tubes 28. and 29, with the rotation of the large gear 20 for each of the sections

7 and 8.

  The end of the third extensible tube 29 is

  coupled through a pivot mechanism which will be de-

  hereinafter referred to a reflector cover 5a covering the middle

  The extensible tube 29 has a cylindrical section fft 29a in which is fitted a cylindrical ring 31 which reinforces it as shown in FIG.

  32 to couple the end 30a of the band of

  30 and the extensible tube 29 is provided within the scope of

of the ring 31.

  The second extensible tube 28, whose diameter

  12 is slightly greater than the diameter 11 of the third tube ex-

  29, has a cylindrical end section 28a and a

  The annular stopper 34 is fitted inside the cylindrical section 28a of the second expandable tube 28 by being attached to this section so that the tube is pushed in the direction

  of the arrow X of FIG. 2, by a thrust ring 33 has

  on the outer periphery of the intermediate portion of the third expandable tube 29 The second expandable tube 28 has a cylindrical section fdt 28b in which is adjusted and

  fixed a disc-shaped ring 36 having an insertion hole

  35 through which is inserted the control band 30

previously mentioned.

  The first expandable tube 27 which has a di-

  5.- meter 13 slightly greater than the diameter 12 of the second expandable tube 28, has a cylindrical section end portion

  27a, in which is adjusted and fixed an annulment device

  38 extends in the direction of the arrow X of Figure 2 by a thrust ring 31 fitted on the outer periphery of an intermediate portion of the second expandable tube 28 The first extensible tube 27 has a fft of cylindrical section 27 b

  wherein a cylindrical member 40 having a guiding opening

  39 through which is guided the control strip 30 of the first control section 7, is fixed by a positioning screw 41 to the cylindrical section 27 b A guide member 42 for guiding the control strip 30 is provided to

  inside the guide opening 39.

  The control strip 30 is of sufficient length

  to develop the expandable tubes 27, 28 and 29

  than at a desired position An insertion hole 30b in the-

  which penetrates the section 20a of the large gear 20 above, is formed in the longitudinal direction of the control strip, so that its diametrical dimension corresponds to the gear section 20a The control strip 20 is controlled along

  an arcuate curved section of strip 43 on the periphery

  outer end of the large gear 20, while the other end of this band can be moved towards the upper end of the frame 1 along a guide 45 formed on a

  vertical portion 44 of this frame 1.

  the extension-contraction mechanism 10, which has the same construction as the previously mentioned extension-contraction mechanism 9, is provided between the second section of

  control 8 and the reflecting mirror 5.

  The opposite ends 11a and 11b of the coupling shaft 11, for coupling the control sections 7 and 8 as shown in FIG. 3, are provided with respective sleeves

  46 and 47 One end 11a of the coupling shaft 11 is at Jus-

  and the other end 11b of the coupling shaft 11 is fitted into the through-hole 47a of the other sleeve 47 and is fixed by means of a screw 48 in the through hole 46a of the sleeve 46. o these two parts being fixed to each other by

a nut 49.

  the operation of this example of

  This operation will now be described in connection with the case where the reflecting mirror 5

  is projected forward from the front 4 of the chassis 1.

  First of all, the driving motor 6 is

  ordered, for example by remote control The effort of

  rotational translation of the drive motor 6 transmitted by the rotary control shaft 12, the worm gear 14, integral with the drive shaft 12, the worm gear 15 meshing with the worm gear 14, the

  anti-overload mechanism 18, the clutch plate 16, the cavities

  16 on a c 8 tee of the clutch plate 16, the

  small gear 19 engaged with the cavities 16a and the large

  graining 20 meshing with the small gear 19, in the order

  so mentioned, so as to cause the rotation of the large

  at a predetermined speed. The rotation of the large

  As a result of the grading 20 being caused, the control band 30 which meshes with the section 20a of the large gear 20 is guided through the guiding aperture 39 of the first section of the

order 7.

  However, the rotational drive force

  transmitted from the small gear 19 is transmitted by

  of the control shaft 17 to which the small gear 19 is fixed, the sleeve 4, the coupling shaft 11 and the sleeve 47, in the aforementioned order, to the control shaft 23 of

  the second control section 8 Since this effort of training

  rotation is transmitted through the small

  in one piece with the control shaft 23 and the large gear meshing with the small gear 24, the large gear 25 is rotated at the same speed as the large gear 20 in the first control section 7 mentioned above Thus, the other control band 30 which meshes with the section 25a of the large gear 25, is guided

  from the guide opening (not shown) of the second

  of control section 8 in synchronism with the control band

  Mande 30 previously mentioned.

  When the control strips 30 are guided

  through their respective guide openings 39 in synchronization with

  the third extensible tubes 29 to which the tips 30 have control strips 30 are fixed by

  the coupling members 32 are pushed forward along the

  inner peripheral faces of the second expandable tubes 28.

7.-

  the third extensible tube 29 is pushed until the

  thrust ring 33 fitted on the outer periphery of the tube 29 is brought into contact with the stop member 34 fixed at the end of the

  second expandable tube 28, as shown in FIG.

  In sequence, the stop member 34 is pushed, so that the second expandable tube 28 is pushed forward along the inner periphery of the first expandable tube 27. The second expandable tube 28 is pushed along the inner periphery. of the first expandable tube 27, until the thrust ring 37 is adjusted to

  the outer periphery of the tube 28 comes to engage the organ of ar-

  In this way, the reflector cover 5 having the reflecting mirror 5 housed in the opening 4 formed on the front 4 of the frame 1, so as to cover the front of the projection lenses 2, is fixed at the end of the first extensible tube 27. , is

  projected by the two extension-contrac-

  9 and 10, as shown in Figure 1.

  the pivot mechanism 50 provided between the cover

  5 a flector and the ends of the third extension tubes 29,

  operates to correct the mounting position of the reflected mirror.

  5 to match the light projection optical system in which light emitted from the cathode ray tubes 3 is projected onto a screen 51 by the projection lenses 2, and the position of mounting of the reflecting mirror is fixed by stopping sections provided

  in the vicinity of the pivot mechanisms 50 Thus, the reflecting mirror

  5 is held motionless in a position in agreement

  with the aforementioned light projection optical system.

  Now we will describe the operation

  both to move the reflecting mirror 5 from the position

  shown in FIG. 1 in a storage position such as

  is represented in dashes in the figure.

  In this case, the drive motor 6 is

  ordered in the opposite direction to that of the previous operation.

  The driving force in rotation of the control motor 6 is

  transmitted via the rotational control shaft

  12 of the worm gear 14 forming part of the

  12, the worm wheel 15 meshing with the worm gear 14, the anti-overload mechanism 18, the clutch plate 15, the small gear 19 meshing with the cavities 16 has arranged on a side of the clutch plate 8.- 16, and the large gear 20 meshing with the small engreanage 19, in the order thus mentioned, to cause the rotation of the

  large gear 20 at a predetermined speed With the rotation

  of the large gear 20, the control band 30 meshing with the section 20a of this large gear 20, tends to move

  towards the upper end of chassis 1 through the

  guide portion 39 of the first control section 7, the

  52 and along the guide member 45.

  The rotational drive force transmitted from the control motor 6 to the small gear 19 is also transmitted via the control shaft 17 fixed to this small gear 19, the sleeve 46, the gear shaft. coupling 11 and the sleeve 47 to the control shaft 23 of the second control section 8 Since this rotational driving force is further transmitted through the small gear 24 forming part of the control shaft 23 and of the large gear 25 meshing with the control shaft 239 the large gear 25 is rotated in synchronism with the large gear 20 in the first control section 7

  mentioned above, and at the same speed as this great engrena-

  Thus, the other control strip 30 meshing with the section 25a of the large gear 25 is moved through an opening (not shown) of the second control section 8.

  in synchronism with the previously mentioned control band 30

tioned.

  Since the two control strips 30 are

  through their respective apertures 52 in synchronism

  one with the other, the third expandable tubes 29,

  what are the ends of the control strips,

  coupling members 32 are pushed inside the barrel of the second expandable tubes 28 along the periphery

  The third extensible tube 29 is retractable

  until the lower end 31a of the ring 31 fits

  in the barrel of the tube 29, meets the upper end 53a of the ring 53 fitted to the barrel of the second expandable tube 28

  consequently, the ring 53 is pushed and the second tube

  ble 28 is retracted toward the barrel of the first expandable tube 29 along the inner periphery thereof until it is stopped in a position close to the guiding apertures

  39 of the control sections 7 and 8 Thus, the reflective cover

9, _ 2505117

  5a having the reflecting mirror 5 is housed in the

  4 on the front 4 of frame 1 by the mechanisms

  my extension-contraction 9 and 10 as shown

in dashed lines in Figure 1.

  When the cover 5a of the reflector is retracted into the opening 4a, the lower edge of the cover 5a is brought into contact with the bottom Ib of the frame 1 and its edge

  opposite to this lower edge revolves around the mechanisms

  pivoted 50 towards the frame 1 So the lid

  5a reflector is housed in the opening 4a so as to cover

  open the front parts of the projection lenses 2.

  Although the above description concerns the

  where the reflecting mirror 5 is automatically moved forward from the front 4 of the frame 1 and also in

  the opposite direction to the front 4 of the frame 1 by the effort of

  the driving of the control motor 6, the m 4 me operation can 4 be caused manually as will be described below in

referring to Figures 5 and 6.

  An operating lever 55 rotatably mounted on the outer casing 13 of the first control section 7 by

  via a pivot 54 is turned in the direction of the

  guilles of a watch according to Figure 5 It follows that one end 57 b of a push rod 57 whose other end

  57 a is mounted on the aforementioned operating lever 55 by the in-

  intermediate axis 56, protrudes to the left from

  an insertion hole 58 formed in the outer casing 13.

  As a result, a plate 59 attached to the end 57b of the rod of

  thrust 57, as well as the small gear mentioned above 19 in the-

  which the plate 59 is mounted, are both moved in di-

  longitudinal rection of the control shaft 17 Consequently,

  a cavity 19 formed on the outer periphery of the small engreg-

  19 is detached from a projection 16 formed on one side of the

  Thus, the small clutch 19 and the

  clutch 16 are separated from each other and, in this state, by rotating the plate 59 in a predetermined direction,

  the control shaft 17, the small gear 19 and the large gear

  swim 16 can be rotated to manually move

  the reflecting mirror 5 in a predetermined direction through the

  mediate the two mechanisms extension-contraction 9 and 10.

  As is evident from the foregoing, with the video projection apparatus according to the present invention, wherein the projection lenses and the cathode ray tubes are disposed within a

  box-shaped frame and in which a reflective mirror

  sant is mounted on the front of the frame, this apparatus also comprising a control source, a first and a second control section controlled as a pair by the control source, a pair of extension-contraction mechanisms

  arranged parallel between the respective control sections

  reflective mirror and controlled in extension and contraction by the driving force of the control sections, while a coupling shaft is disposed between the rear ends of the cathode ray tube at the rear end of the frame, and cuts the control sections to each other, the two extension-contraction mechanisms being controlled for extension and contraction in synchronism with each other by the coupling shaft controlled by the control forces. 'entratnement

  control sections, the reflecting mirror may be

  tomatically moved forward to a predetermined position and then retracted into the chassis with a very simple construction

  and so the goal can be easily achieved.

  In addition, since the two mechanisms of

  sion-contraction are controlled in extension and contraction in synchronism with each other, it is possible to move

  reflective mirror while maintaining its correct posi-

  in accordance with the video optical system.

  On the other hand, since the coupling tree

  is provided between the rear end of the cathode ray tubes

  that and the rear end of the chassis, it is not necessary to provide a particular space for its disposal, and this

  contributes to the reduction of the dimensions of the entire

the same. 11.-

Claims (4)

  1. A video projection apparatus, characterized in that it comprises s a box-shaped frame in which are housed projection lenses and cathode ray tubes and which is provided frontally with a reflecting mirror, a control source a first and a second control section controlled as a pair by the control source,   a pair of extension-contraction mechanisms arranged parallel   in parallel between said respective control sections and the reflecting mirror and controlled for expansion and contraction by the action of the control sections, a coupling shaft disposed between the rear ends of the cathode ray tubes and the rear end of the frame and coupling the control sections to each other, both   extension-contraction mechanisms being ordered for the ex-   tension and contraction in synchronism with each other by the coupling shaft controlled by the action of the sections of command.   2. Video projection apparatus according to the   claim 1, characterized in that the first and second control sections are disposed within the frame adjacent to the rear end thereof and adjacent on the opposite side of it.   3. Video projection apparatus according to the   claim 1, characterized in that each of the two mechanisms   extension-contraction comprises a plurality of extensor tubes   Cylindrical blisters with different diameters and a band   of control extending through these expandable tubes and   mandating extension and contraction in the longitudinal direction of these extensible tubes.   4. Video protection device according to the   claim 3, characterized in that the control strip is an elongate flexible bar with teeth or holes for   mesh with a pignon or worm gear of each than control section.