WO2004003660A1

WO2004003660A1 - Projector

Info

Publication number: WO2004003660A1
Application number: PCT/NO2003/000218
Authority: WO
Inventors: Morten Gulliksen
Original assignee: Bård Eker Industrial Design As
Priority date: 2002-07-01
Filing date: 2003-06-27
Publication date: 2004-01-08
Also published as: NO20023191D0; NO20023191L; AU2003280450A1; NO317228B1

Abstract

A new and improved projector comprising a projector housing (6) containing a plurality of components (13), a cover (4) and at least one cooling fan (1) attached to the upper side (11) of the projector housing. The cover (4) is designed to accommodate the cooling fan and is, with the aid of means (4a, 6a), movable between a first position and a second position relative to the upper side (11) of the projector housing. The fan (1) comprises a plurality of fan blades (3) rotatably attached to respective arms (2) which are connected to the fan motor (la), whereby each of the fan blades can rotate between a first position in which the blade face lies in a plane that is essentially coincident with the rotational plane of the fan (1) and a second position in which the blade face lies in a plane that is essentially at right angles to the plane of rotation of the fan.

Description

PROJECTOR

This invention relates to the thermal design and logical construction of projectors primarily for the reproduction of images. More specifically, the invention relates to a new type of projector comprising a projector housing containing a plurality of components (13), as disclosed in the preamble of claim 1.

Increasingly stringent demands are being made as regards the size and noise level of projectors. As projectors are to an increasing extent mobile units, it is desirable that they should be relatively small, and this calls for a compact design. Furthermore, there are standards set by the authorities for the temperature of the air that cools the projector lamps, i.e., the cooling air must not exceed a given temperature as it flows out of the projector. The most important function of the cooling fan is to mix the hot air from the lamp so that none of the parts that can be touched during normal use become warmer than allowed by regulatory authorities such as UL and NEMKO.

Since, as mentioned, the projectors themselves are relatively small, today's cooling fans and internal cooling ducts are inevitably also small. This means that the fans must rotate at high speeds in order to move the necessary air volumes per time unit past the lamp(s), i.e., the fans must quickly and with small blades transport the air volumes through the projector so as to provide the necessary cooling. This results in an unpleasant and often unacceptable loud noise, to which the motor, the fan and the through-flowing air all contribute.

With today's DLP technology, it is not possible to further reduce the generation of heat from the projectors without sacrificing light intensity. Therefore, with conventional designs, today's projector designers are approaching a theoretical size limit since fans must blow a certain amount of hot air out of the projector. If the size is reduced further, this will, in a conventional design with small fans, result in disturbing noise from the fans that are to remove this heat.

There is therefore a need for a compact projector which allows a further reduction of external size, whilst the projector complies with current standards and requirements as regards noise and heat emission.

The invention fulfils the aforementioned requirements in that it provides a device as disclosed in the preamble of claim 1. The projector according to the invention is characterised by a cover and at least one cooling fan attached to the upper side of the projector housing, wherein the cover is designed to accommodate the fan and is, with the aid of means, movable between a first position and a second position relative to the upper side of the projector housing.

Additional features of the invention are set forth in the other, dependent claims 2-15.

The projector according to the invention comprises in its most basic form a relatively large radial fan placed horizontally on the top of the projector housing, immediately beneath a top cover. The fan is foldable so that the projector height during transport is less than its height during operation.

One embodiment of the invention will now be described with reference to attached drawings, wherein the same parts are indicated by means of the same reference numerals.

Figure 1 is a schematic cross-section of the projector according to the invention with the blades of the rotating and foldable fan in an unfolded position and the cover in an upper position.

Figure la is an enlarged section of Figure 1.

Figure 2 is a schematic cross-section of the projector according to the invention with the blades on the foldable fan in a folded position and the cover in a lower position.

Figure 3 is a schematic perspective view of an embodiment of the microproj ector according to the invention.

Figure 4 shows an embodiment of the fan in the device according to the invention.

Figure 5 is a top view of the fan, with the blades in an unfolded position.

Figure 6 is a top view of the fan with the blades in a folded position.

In its most basic form, the projector according to the invention comprises a new and improved projector housing 6, which may house, for example, the electrical, optical and mechanical components of the projector. It is these components - and chiefly the lamp(s) - that are to be cooled. These components are not encompassed by the invention and are therefore not shown individually, but are hereinafter refened to and indicated collectively as the components 13.

The housing 6 is designed, for example, so as to be capable of being placed on a surface, and in its lower face is equipped with a plurality of openings 7, through which ambient air can preferably be drawn in. The intake openings 7 may also be in the side walls of the housing, but this has not been illustrated specifically. The intake openings may also be of any suitable shape and may in addition be adapted to the components 13 and any external markings (not shown) or feet 17 on the underside of the projector housing.

The projector housing 6 in its upper side 11 is equipped with at least one opening 8, through which air may preferably be drawn out of the housing. This outlet opening 8 (or openings) may be of any suitable shape and may in addition be adapted to the components 13. The outlet opening may advantageously be equipped with a grille 8a.

A cover 4 is attached to the projector housing 6 so that it at least covers the outlet opening 8. The cover is equipped with a plurality of openings 5. Figure 3 shows that in the embodiment in question these openings are located on the side face of the cover. The cover openings 5 may have any suitable shape and may also be located on the upper side of the cover.

Figure la, which is an enlarged section of Figure 1, shows that the cover is attached to the projector housing 6 by respective threads 4a, 6a. The cover 4 may thus be raised and lowered relative to the projector housing 6 by moving the two parts relative to each other with a screw movement. The screw movement can be effected using motor power or manually, e.g., by the user gripping the cover and turning it.

Mounted in the cover 4 is a fan 1 which comprises a motor la connected to a plurality of fan arms 2, wherein each fan arm is attached to respective fan blades 3. The fan 1 is mounted so that the fan arms and blades can be rotated in a plane that is essentially parallel to the upper side 11 of the projector housing 6. In the embodiment shown in the figures, the fan 1 covers an area that is only slightly smaller than the base area of the projector housing. Figures 5 and 6 show an embodiment having six fan arms and associated blades. The number and length of the arms and the blades, and the individual area of the blades can be adapted to the cooling requirement of the components 13 and the design of the projector housing.

Each fan blade 3 is rotatably attached to a respective fan arm 2 in such manner that the blade is able to rotate between a first position in which the blade face lies in a plane that is essentially coincident with the rotational plane of the fan 1 (see Figures 2 and 6) and a second position in which the blade face lies in a plane that is essentially at right angle to the rotational plane of the fan (see Figures 1 and 5). The figures show the fan blades rotatably fastened to respective arms by means of a tubular hinge 14 and a snap-on hinge 15, but the way they are fastened should not be limited to this solution. Each fan blade 3 comprises an abutting member 3 a which abuts against a respective fan arm when the fan blade is in the second position (see Fig. 1). This helps to keep the fan blade in the second position when the fan rotates.

As mentioned above, the cover 4 can be moved between a first position close to the projector housing 6, and which corresponds to the first position of the fan blades 3, to a second position more remote from the projector housing, where the space between the upper face 11 of the projector housing and the cover is sufficiently large to allow the blades to assume the second position (i.e., the unfolded position, cf. Figs. 1 and 5).

The aforementioned movement of the cover may advantageously also be used to screw the actual projector on and off (by means of known switch arrangements that are not shown). In this connection, the respective first positions of the cover and the fan blades correspond to an "ON" state in which the projector is in operation and the fan rotates. The respective second positions of the cover and the fan blades coπespond to an "OFF" state in which the projector is switched off and the fan does not rotate. However, it is a requirement that an automatic function be incorporated which allows the fan to rotate for a given period after the lamp has been switched off, and before the cover is lowered over the projector housing and enters the "OFF" state. A functionality of this kind is necessary in order to avoid overheating of the components.

Furthermore, the projector according to the invention may comprise folding feet 17, in order to make the projector even more compact when switched off. A folding of this kind can be done in a manner that is known per se, via. e.g., a mechanical transmission of the movement of the cover 4 to the feet 17, so that these are unfolded when the cover is turned to put the projector in the "ON" state, and are folded into the projector housing when the projector is in the "OFF" state.

The space between the cover and the projector housing may advantageously be designed so that the fan blades are kept in the first position and rotation of the motor is prevented when the projector is switched off.

Figures 2 and 6 thus show an embodiment of the projector according to the invention, in a switched-off state (first position) with the fan blades folded. In this state, the projector is extremely compact and portable. The turnable cover 4 may advantageously be designed so that it covers - and thus protects - the lens 16 when the projector is in this switched-off state.

The projector can - preferably via its feet 17 - be placed on a surface and connected to a power source in a known manner. When the user turns the cover 4, it is raised by means of the thread connection 4a, 6a into the second position. The fan per se can now rotate. The fan blades 3 are unfolded, i.e., they rotate about their respective fan arms 2 and fall down in order to assume the second position. If the blades 3 do not fall down because of the force of gravity, the air pressure and the vibrations will ensure that they do so. The actual projector components 13 (e.g., lamp, colour wheel etc.) and the fan motor la are also switched on, and the fan blades 3 rotate.

The rotational direction of the fan and the design of the blades are such that surrounding air will be drawn in through the openings 7 in the housing 6. The air is drawn past vital components 13 that are to be cooled, and heated air passes up through the opening 8 in the upper face 11 of the housing and into the chamber 12 between the projector housing and the cover. The fan blades send the heated air out through the cover openings 5. The airflow described is indicated by the arrow marked with the reference numeral 10. To prevent hot air from being drawn back in through the cover openings, these openings 5 cover only between 90° and 300° - preferably 200° - of the total circumference.

In order to switch the projector off, the cover 4 is turned - preferably in the opposite direction to that in which it was turned to switch the projector on. The fan is then stopped, the cover is lowered by means of the thread connection 4a, 6a to the first position and the fan blades 3 are folded, i.e., they rotate about their respective fan arms 2 and assume the first position. The projector according to the invention dramatically changes the prospects of producing small, low-noise projectors, and an improvement of 12-20 decibels of noise is expected in comparison with the competing designs having a corresponding volume.

The projector housing 6 and the cover 4 has been shown here with a circular base. However, the device according to the invention should not be limited to this, but should also comprise projector housings and covers having bases of other shapes.

Furthermore, it should be understood that the fan blades may have any other appropriate planar shape, and also be curved.

The projector according to the invention may be made of any suitable materials, and the fan blades 3 may advantageously be made of a flexible material.

List of parts described:

I Fan la Fan motor 2 Fan arms

3 Fan blades

3 a Abutting members

4 Cover 4a Threads 5 Cover openings

6 Projector housing 6a Threads

7 Intake openings

8 Outlet opening 8a Grille

10 Airflow

I I Upper face o f the proj ector

12 Chamber

13 Components 14 Tubular hinge

15 Snap-on hinge

16 Lens

17 Feet

Claims

P a t e n t c l a i m s

1.

A projector comprising a projector housing (6) containing a plurality of components

(13), characterised by a cover (4) and at least one cooling fan (1) attached to the upper side (11) of the projector housing, wherein the cover (4) is designed to accommodate the cooling fan and is, with the aid of means (4a, 6a), movable between a first position and a second position relative to the upper side (11) of the projector housing.

2.

A projector according to claim 1, characterised in that the fan (1) comprises a plurality of fan blades (3) rotatably attached to respective arms (2) which are connected to the fan motor (la), wherein each of the fan blades can rotate between a first position in which the blade face lies in a plane that is essentially coincident with the rotational plane of the fan (1) and a second position in which the blade face lies in a plane that is essentially at right angles to the rotational plane of the fan.

3. A projector according to claim 2, characterised in that each fan blade (3) comprises an abutting member (3a) that abuts against a respective fan arm (2) when the fan blade is in the second position.

4. A projector according to claims 1 and 2, characterised in that the first and second positions of the cover are coincident with the respective first and second positions of the fan blades.

5. A projector according to claim 1 , characterised in that the projector housing (6) is equipped with a plurality of openings (7), through which surrounding air can be drawn in, and in its upper side (11) is equipped with at least one opening (8), through which air can be drawn out of the housing.

6.

A projector according to claims 1 and 5, characterised in that the cover (4) is attached to the projector housing (6) so that it covers the outlet opening (8).

7.

A projector according to claim 1, characterised in that the cover is equipped with a plurality of openings (5), through which air can be expelled from the cover.

8.

A projector according to claim 1, characterised in that the cover (4) is attached to the projector housing (6) by means of respective threads (4a, 6a) so as to be capable of being raised and lowered relative to the projector housing (6) by moving the two parts relative to each other with a screw movement.

9.

A projector according to claim 1, characterised in that the fan (1) covers an area that is smaller than or approximately equal to the base area of the projector housing.

10.

A projector according to claim 1, characterised in that the first position of the cover (4) is close to the projector housing (6) and coπesponds to the first position of the fan blades (3), and that the second position of the cover (4) is more remote from the projector housing, and where a space or chamber (12) is formed between the upper face (11) of the projector housing and the cover that is sufficiently large to allow the fan blades to assume the second position.

11. A projector according to claim 1, characterised in that the movement of the cover between the first and second positions also screws the actual projector on and off.

12.

A projector according to claim 10, characterised in that the chamber (12) between the cover and the projector housing is so designed that the fan blades are kept in the first position and rotation of the motor is prevented when the projector is switched off.

13.

A projector according to claim 1, characterised in that the cover (4) is so designed that it covers the projector lens (16) when the projector is in the switched-off state.

14.

A projector according to claim 7, characterised in that the cover openings (5) cover between 90° and 300° - preferably 200° - of the total circumference of the projector.

15.

A projector according to claim 1, characterised in that the projector housing (6) and the cover (4) having circular bases.

16. A projector comprising a projector housing (6) containing a plurality of components (13) and at least one cooling fan (1), characterised in that the rotational plane of the cooling fan (1) is approximately parallel to the horizontal plane of the projector and that the diameter of the cooling fan is smaller than or approximately equal to the base area of the projector housing.