JPS6040066Y2 - projection television - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a projection television in which an image from a cathode ray tube is enlarged and formed on a screen using a projection optical system.

Conventionally, projection television screen devices have always been
The screen is held at the imaging position by a fixed frame and installed.

As a result, the entire projection television device becomes extremely large, which is inconvenient when transporting and installing it.
Since the screen surface is always exposed, it has the disadvantage that the screen surface gets dirty.

Furthermore, since the screens used in projection televisions are generally high-brightness screens with strong directivity, soiling of the screens causes a significant deterioration in image quality.

This invention takes into account the above-mentioned drawbacks of the conventional technology, and by winding a flexible screen around a rotating drum, the screen can be stored when it is not needed.Next, this invention will be explained in detail with drawings. do.

First, a description will be given of FIGS. 1 to 5 showing the configuration on which this invention is based.

In those drawings, 1 is a projection television main body frame, 2 is a mounting base provided at the bottom of the main body frame 1, and 3 is a cathode ray tube mounted and fixed on the mounting base 2 with the tube axis directed upward; Reference numeral 4 denotes a magnifying projection optical system consisting of projection optical elements such as lenses attached to a cathode ray tube 3, 5 a light exit portion of the magnifying projection optical system 4 directed forward, and 6 attached to one side of the main body frame 1. The receiver having a rectangular cross section is a plate, the receiver 7 is a reflecting mirror that is fixed to the inner surface of the plate 6 and constitutes a reflective optical system, and the reference numeral 8 is a reflecting mirror that reflects the light emitted from the light output part 5 of the enlarged projection optical system 4. Light passing holes 9 and 10 are transparently provided in the main body frame 1 so as to project images onto 7.
are fixed stands fixed to both sides of the main body frame 1, and 11 is a rotary drum rotatably attached to both fixed stands 9 and 10 via a fixed shaft 12, to which rotational force is applied by a spring.

13 is an entry/exit groove provided on the upper surface of the main body frame 1; 14.15
are a plurality of pipes 14a, 14b, each having a different diameter,
14c...14n and 15a, 15b, 15c...
・15n is installed in each base pipe 1 in order from the one with the largest diameter.
4a*15a, each of which is inserted into the inlet/outlet groove 13 and connected to the base pipes 14a and 15.
pipes 14a to 14n are fixed to both fixed stands 9 and 10 and arranged in parallel.

The inner diameter and outer diameter of each support rod 14.1
5, the lower ends of the upper pipes become smaller and smaller so that they are fixed to the upper ends of the lower pipes when the pipes are extended, forming a telescopic antenna shape.

Reference numeral 16 denotes a horizontal bar whose both ends are fixed to the tips of the supporting rods 14 and 15, and 17 is a flexible, high-intensity screen whose upper and lower ends are fixed to the horizontal bar 16 and the rotating drum 11. For example, It is made of fabric coated with aluminum vapor deposition.

Next, the operation of the projection television will be explained.

First, when using the screen 17, both support rods 14,
15, each pipe 14a to 14n, 15a
15n are fixed to each other by friction at their lower and upper ends, and the screen 17 is pulled out by the horizontal bars 16.

Then, due to the tensile force due to the rotational force of the rotating drum 11,
The screen is stretched at a preset viewing angle without loosening.

Therefore, the image on the cathode ray tube 3 is emitted from the light emitting section 5 via the enlarged projection optical system 4, this light is reflected by the reflecting mirror 7, and an enlarged image is projected onto the screen 17.

Next, if the screen 17 is not used, each support rod 1
4 and 15 from above, each pipe 14a to 1
4n, 15a to 15n are sequentially inserted and housed in each base pipe 14a, 15a, as shown in FIGS. 4 and 5.

At this time, the screen 17 is wound up and stored on the rotating drum 11 by the rotational force of the rotating drum 11.

And the screen 17 that is not wound around the rotating drum 11
The upper surface of the television receiver main body frame 1 has an entrance/exit groove 13.
It is located within and is not exposed to the outside.

Incidentally, in a projection television, there are optical path length differences, field curvature aberrations, etc. of the enlargement projection optical system 4.

This idea was made with the above points in mind,
This invention will be explained with reference to FIGS. 6 and 7 showing one embodiment thereof.

That is, in the same figure, the same symbols as in FIGS. 1 to 5 indicate the same or corresponding parts, 18 is one fixed base formed in an arc shape having a predetermined center of curvature, and 19 is one fixed base. One support rod attached to 18,
As shown in FIG. 7, each pipe 19at 19by
19c'' and 19n are formed in an arc shape with one side on the screen 17 side having the same center of curvature M, and the other sides on the opposite side of the screen 17 have centers of curvature A and B whose positions are sequentially shifted.

As shown in C, it is formed in an arc shape with slightly different centers of curvature.

Therefore, when using the screen 17, the support rod 1
When the pipe 9 is pulled up, each of the pipes 19a to 19n is thin at the upper end and thick at the lower end.
Each pipe 19a to 19n as in the case of FIGS.
are fixed to each other at their lower and upper ends.

In addition, another support rod (not shown) having the same shape as the support rod 19
is provided, pulled out and fixed in the same manner as described above.

The support rod 19 has an arc shape having a center of curvature that is substantially the same as the center of curvature M on one side of each of the pipes 19a to 19n.

At this time, the screen 17 pulled out by the horizontal beam 16 is also joined to the back side of the support rod 19, and stretched in an arc shape having the same center of curvature as the support rod 19.

That is, the center of curvature M on one side of each pipe 19a to 19n
is determined by the incident angle of the enlarged projection optical system 4, the reflection and diffusion characteristics of the screen 17, the viewing conditions, the magnitude of field curvature on the screen 17 surface, etc.
By curving 19n, when the support rod 19 is pulled out, the screen 17 can be stretched in an arc shape having a predetermined center of curvature M, and the screen 17 can be stored by being wound around the rotating drum 11 in the same way as described above. It is done.

As described above, according to the projection television of this invention, an enlarged projection optical system is provided on the cathode ray tube fixed to the projection television body frame, and the light emitting part of the enlarged projection optical system is installed facing forward. A reflective optical system is provided at the front of the main body frame to project the light from the light emitting part upward to the rear, fixed stands are fixed to both sides of the main body frame, and a rotating drum is installed between the fixed stands. It is rotatably attached, and the support rods are attached to both fixing bases, passing through the upper surface of the main body frame and parallel to each other.When the two support rods are stored, they are stored in the base pipe, and when extended, the lower end of the upper pipe is directed downward. consisting of a plurality of pipes whose inner and outer diameters are successively smaller fixed to the upper end of the pipe, and each of the pipes:
One side is formed in an arc shape with the same center of curvature, and the other side is formed in an arc shape with a different center of curvature, horizontal bars are attached to the tips of both support rods, and the upper end of the flexible screen is The lower end of the screen is guided from the back side of both support rods into the main body frame through the entrance/exit groove provided on the upper surface of the main body frame, and the screen is fixed to the rotating drum. By installing a spring that applies rotational force in the direction of winding up the screen, when the screen is not in use, the extendable support rod can be contracted and the ends and ends of the support rod can be stored in the base pipe. In addition, the screen can be wound around a rotating drum and stored in the frame of the television body, making the entire projection television device more compact and preventing the screen surface from becoming dirty. , image quality can be maintained.

In addition, in this type of reflection type projection television, it is generally extremely difficult to handle the screen during the manufacturing process, packaging, transportation, etc., but this difficulty in handling is eliminated.

Furthermore, when the support rod is extended, each pipe becomes arcuate, so
The screen surface can be provided with a curved surface, and the optical path length difference and field curvature aberration due to the enlarged projection optical system can be absorbed, and image quality can be improved.

Further, the curling tendency that occurs in the screen when the screen is stored acts so that it is stretched along the arcuate support rod when the screen is used, so that a screen surface with a desired curvature can be obtained.

[Brief explanation of the drawing]

Figures 1 to 5 show the basic structure of the projection television of this invention. Figure 1 is a cutaway side view, Figure 2 is a front view of the screen in use, and Figure 3 is a 4 is a front view of the screen with the screen retracted, FIG. 5 is a right side view of FIG. 4, and FIGS. 6 and 7 are one embodiment of the projection television of this invention. and the sixth
The figure is a cutaway side view, and FIG. 7 is a partial sectional view of the support rod. 1...Television body frame, 3...Cathode ray tube, 4...Enlargement projection optical system, 5...
Light emission part, 9.10, 18... Fixed stand, 11.
...Rotating drum, 13...Delivery and delivery, 14
．． 15. 19...Support rod, 14a, 15a
, 19a...Base pipe, 14b, 14c...
14n, 15b, 15c...15nt19b...19
n...Pipe, 16...Horizontal beam, 17.
·····screen.

Claims (1)

[Scope of utility model registration request] An enlarged projection optical system is provided on a cathode ray tube fixed to the projection television body frame, and the enlarged projection optical system is installed with the light emitting part facing forward, and the light emitting part from the light emitting part is installed in the front part of the main body frame. A reflective optical system for projecting light upward to the rear is provided, and fixed stands are fixed to each side of the main body frame,
A rotary drum is rotatably mounted between the fixed bases, support rods are provided in parallel on both fixed bases passing through the upper surface of the main body frame, and each of the support rods is stored in the base pipe when stored. , during expansion, the lower end of the upper pipe is fixed to the upper end of the lower pipe, and each pipe is made up of a plurality of pipes whose inner and outer diameters are successively smaller, and one side of each pipe has the same curvature. The screen is formed into an arc shape having a center, and the other side is shaped into an arc shape having a different center of curvature, horizontal bars are attached to the tips of both support rods, and the upper end of the flexible screen is fixed to the horizontal bars. , a direction in which the lower end of the screen is guided from the back side of both support rods into the main body frame through an in/out groove provided on the upper surface of the main body frame, and is fixed to the rotating drum, and the screen is wound around the rotating drum. A projection television equipped with a spring that provides rotational force.