JPH11144521A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide as projector which can be cooled sufficiently by natural convection alone without use of a cooling fan. SOLUTION: In a projector having a cylindrical case 20 closed at its rear, a light source 21 provide inside the case 20 in such a way as to emit light from an opening in the front of the case 20, a light shielding means 23 provided at the opening in the case 20, and a projecting lens 24 provided in front of the light shielding means 23, an air inlet 26 is provided in the lower portion of the case 20 and near the opening, and an exhaust port 27 is provided in the upper portion of case 20 opposite to the air inlet 26. Further, a vent cylinder 28 extending backward from the exhaust port 27 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a projector. More specifically, the present invention relates to a large floodlight used in a theater, an event hall, and the like.

[0002]

2. Description of the Related Art Conventionally, floodlights used in theaters, event venues, and the like can be used almost stably up to about 1 Kw, although the temperature inside the case becomes somewhat high due to natural convection ventilation. However, if the lamp is used for a long time, the lamp, which can be said to be the life of the floodlight, will be broken and become unusable, and the mechanism inside the floodlight will be distorted.
There is also a concern that it will be a source of various troubles associated with it. Therefore, when the pressure becomes about 2 Kw, the inside of the case becomes extremely hot only by natural convection ventilation, and forced cooling is required.

FIG. 4 is a view showing a conventional natural convection cooling type floodlight, where (a) is a side view showing a partial cross section, and (b).
FIG. 3 is a view showing a variable light shielding plate, and FIG. The light source 2 and the condensing reflector 3 are provided near the opening of a cylindrical case 1 having a rear part closed. The opening of the case 1 is provided with a variable light-shielding plate 4 for changing the shape of the light spot as shown in FIG. 2B and a light-shielding means 5 such as a diaphragm for adjusting the intensity of the light projection. The light shielding means 5 is rotatable with respect to the case 1.

A light projecting lens 7 supported by an extendable lens barrel 6 is provided in front of the light shielding means 5. An air inlet 8 is provided at a lower portion of the case 1, and an air outlet 9 is provided at an upper portion of the case 1 so as to face the air inlet 8.
Is provided. The air intake 8 and the exhaust 9 are provided with louvers 10 for blocking light leaked from the reflecting mirror 3. The case 1 is rotatably attached to a gate-shaped hanging bracket 11 by bolts 12 so that the light projection direction can be changed.

FIG. 5 is a view showing a conventional forced cooling type light projector, and FIG. 5 is a side view showing a partial cross section. This is provided with a forced cooling fan 13 instead of the air intake of the natural convection type floodlight described in FIG.
Others are the same as FIG.

[0006]

In the above-mentioned conventional floodlight, the natural convection floodlight described with reference to FIG. 2 is damaged or case 1
In addition, there is a problem that the light-shielding means 5 and the like are deformed due to thermal expansion, and problems such as operation of the light-shielding means 5 and expansion and contraction of the lens barrel become impossible. In the case of the forced cooling type floodlight described in FIG. 5, when a large number of floodlights are used as in a theater, noise caused by the cooling fan 13 becomes a problem. Further, there is a problem that the vibration of the cooling fan 13 also adversely affects the operation of the light shielding means 5.

FIG. 6 is a diagram showing the relationship between the temperature in the case and the elapsed time from the start of lighting of the conventional 1 Kw and 2 Kw projectors. The vertical axis represents the temperature and the horizontal axis represents the elapsed time.
Indicates 1 Kw, and curve B indicates 2 Kw. 1Kw
For stabilizes at temperature T ₁ of from the temperature T ₀ by subtracting the temperature drop Q ₃ by the heat radiation when no heat radiation. Also 2Kw
For stabilizes at the temperature T ₃ minus the temperature drop Q ₃ 'by heat radiation from the temperature T ₂ at which no heat radiation. Therefore,
Assuming that the stabilization temperature T ₁ in the case of ₁ Kw is a safe temperature, 2
It can be said that in the case of Kw is necessary to dissipate the heat of Q ₄ obtained by subtracting T ₁ from T _3.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to realize a projector capable of sufficiently cooling the inside of a case only by natural convection without using a cooling fan.

[0009]

According to a first aspect of the present invention, there is provided a light projecting device having a cylindrical case having a rear portion closed.
A light source 21 provided in the case 20 so as to emit light from a front opening of the case 20;
Light shielding means 23 provided in the opening of
In a light projector having a light projecting lens 24 provided further forward, an air intake 26 is provided at a lower portion of the case 20 and near an opening, and an upper portion of the case 20 is opposed to the air intake 26. An exhaust port 27 is provided,
Further, a ventilation tube 2 extending from the exhaust port 27 toward the rear portion.
8 is provided.

With this configuration, when hot air from the exhaust port 27 passes through the ventilation tube 28, the ventilation tube 28 functions as a chimney, so that the exhaust is smoothly performed, thereby sucking in fresh air. And the cooling effect is improved.

The invention according to claim 2 is a light shielding plate 29 in which the air intake port 26 has a mountain-shaped or wave-shaped cross section and a mountain-shaped or wave-shaped bent portion formed in an arc shape.
A louver 29 composed of a plurality of sheets a is provided. By employing this configuration, the flow resistance of the air decreases, and the amount of air flowing in increases, so that the cooling effect is improved.

The invention according to claim 3 is characterized in that the ventilation tube 28
Are provided parallel or inclined with respect to the center axis of the case 20. By adopting this configuration, when the ventilation tube is inclined, even if the main body is placed horizontally, the ventilation tube 28 acts as a chimney, so that the exhaust function becomes active and the cooling effect is improved.

[0013]

FIG. 1 is a view showing a first embodiment of the present invention, in which (a) is a side view showing a partial cross section, and (b).
And (c) is an enlarged view of the louver, (d) is a Z of FIG.
It is an arrow view. In the present embodiment, as shown in the figure, a cylindrical case 20 having a polygonal or circular cross section (octagon in the figure) and a closed rear portion is provided. A light source 21 and a reflecting mirror 22 are provided to emit light from the front opening. Case 2
The light shielding means 23 is provided at the opening of the light shielding means 2.
A telescopic lens barrel 2 having a light projecting lens 24 in front of 3
5 are provided. A diaphragm and a variable light-shielding plate as described in FIG. 4B are used for the light-shielding means 23.

An air intake 26 is provided at a lower portion of the case 20 and near the opening, and an exhaust port 27 is provided at an upper portion of the case 20 so as to face the air intake 26.
Is provided. The exhaust port 27 is provided with a ventilation tube 28 extending from the exhaust port 27 toward the rear. The cross section of the ventilation tube 28 is rectangular (other shapes are possible), the length is substantially equal to the length of the case 20, and the front portion (the direction of the opening of the case) 28a is closed in an R shape.

The air inlet 26 has a reflecting mirror 22.
In order to block the light leaked from the front part of FIG. 5, a plurality of peaks are formed as shown in FIG. A louver 29 in which the light shielding plates 29a are arranged at intervals.

In this embodiment assembled as described above, the left and right sides of the case 20 are rotatably supported by the gate-shaped hanging brackets 30 using bolts 31 and are suspended from above. The upper part of the case 20 may be integrated with the case body,
For maintenance and inspection of the inside of the case, it is preferable that the case can be opened and closed by a lid 32 and a hinge 33 as shown by a two-dot chain line as shown in FIG. In this case, the exhaust port 27 and the ventilation tube 28
Is provided on the lid 32.

In the present embodiment thus configured, when the light source 21 is turned on, the temperature inside the case 20 rises. As the temperature inside the case rises, the air inside the case becomes lighter and is discharged from the exhaust port 27 to the outside through the ventilation tube 28. At the same time, fresh air is introduced from the air intake 26 to cool the inside of the case. At this time, FIG.
As shown in (b), when the main body is tilted so that the light projection direction is directed downward, the ventilation tube 28 acts as a chimney, and discharge of heated air becomes active. Thereby, the introduction of fresh air becomes active and the cooling effect is improved.

FIG. 3 is a diagram showing a second embodiment of the present invention. The configuration of the present embodiment is substantially the same as that of the first embodiment, as shown in FIG. 3, except that the ventilation cylinder 28 is inclined with respect to the center axis of the case 20 so that the rear portion is higher. That is, it was provided. A plurality of ventilation cylinders 28 can be provided as shown in the figure. In that case, of course, it is necessary to provide the exhaust port 27 for each ventilation tube.

According to the present embodiment having such a structure, the ventilation tube 28 can perform the chimney operation even when the main body is placed in a horizontal state, and the height of the chimney can be maintained even when the main body is inclined. In order to increase the cooling effect, the cooling effect can be improved by actively introducing fresh air.

[0020]

According to the floodlight of the present invention, since the ventilation tube is provided so as to communicate with the exhaust port provided in the case in which the light source is accommodated, the ventilation tube forms a chimney function, and the inside of the case is provided. The discharge of high-temperature air can be promoted, and the cooling effect inside the case can be improved. In particular, the effects of the present invention are further exhibited in a theater, where downward light is mainly emitted. Further, since the bent portion of the light-shielding plate of the louver is formed in an arc shape, the flow resistance of air is reduced, the introduction of fresh air is facilitated, and the cooling effect can be further improved. Therefore, problems such as damage to the light source due to a rise in the temperature inside the case and inability to operate the light shielding means due to thermal expansion are prevented. Also, since the projector of the present invention does not use a cooling fan,
There is no problem due to noise and vibration.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of the present invention, wherein FIG. 1A is a side view showing a partial cross section, FIGS. 1B and 1C are enlarged views of a louver, and FIG. It is a Z arrow view of the figure.

FIG. 2 is a diagram showing a use state of the first embodiment of the present invention.

FIGS. 3A and 3B are views showing a second embodiment of the present invention, wherein FIG. 3A is a side view showing a partial cross section, and FIG.

FIG. 4 is a diagram showing a conventional natural convection cooling type floodlight;
(A) is a side view showing a partial cross section, (b) is a view showing a variable light shielding plate, and (c) is a view taken in the direction of the arrow Z in (a).

FIG. 5 is a view showing a conventional forced-cooling type floodlight;
FIG. 2 is a side view showing a partial cross section, and FIG.

FIG. 6 is a diagram showing the relationship between the temperature inside the case and the elapsed time of a conventional 1Kw and 2Kw projector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Case 21 ... Light source 22 ... Reflection mirror 23 ... Shielding means 24 ... Light emitting lens 25 ... Barrel 26 ... Air intake 27 ... Outlet 28 ... Ventilation cylinder 29 ... Louver 30 ... Hanging bracket 31 ... Bolt 32 ... Lid 33 ... Hinges

Claims (3)

[Claims] 1. A cylindrical case (20) having a closed rear portion.
A light source (21) provided in the case (20) so as to emit light from a front opening of the case (20);
Light shielding means (2) provided in the opening of the case (20).
3) and a light projector provided with a light projection lens (24) provided in front of the light shielding means (23), wherein an air intake port (26) is provided below the case (20) and near the opening. With the air intake (2
Exhaust port (27) at the top of case (20) facing 6)
And a vent tube (28) extending from the exhaust port (27) toward the rear. 2. A louver (2) comprising a plurality of light-shielding plates (29a) having a mountain-shaped or wave-shaped cross-section and a mountain-shaped or wave-shaped bent portion formed in an arc shape, in the air intake port (26). 29. The floodlight according to claim 1, further comprising (29). 3. The floodlight according to claim 1, wherein the ventilation tube (28) is provided parallel or inclined with respect to a central axis of the case (20).