JPH03214141A - Light emitting device for overhead projector - Google Patents

Abstract

PURPOSE:To simplify the structure of this light emitting device and to reduce the cost thereof by using a spring member also as a knob for operating a slide member. CONSTITUTION:When a lamp 14 is relocated, the slide member 21 is operated while the spring member 23 which is used also as the knob is pinched. At this time, the engagement of an engagement means is temporarily released by resisting to the spring force of the spring member 23 and the slide member 21 is slided. Besides, the engagement means is engaged based on the spring force by the member 23 at a position where the other lamp is opposed to a condenser lens 15. By using the spring member 23 also as the knob in such a way, the structure is simplified and the light emitting device is inexpensively obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light emitting device, particularly to a light emitting device for an overhead projector.

[Conventional technology]

For example, a reflective overhead projector includes a base on which a translucent original is placed, and a head disposed above the base.

The head includes a light emitting device having a lamp and a condenser lens, a projection device having a projection lens and a projection mirror,
It also includes a case to store them.

In the light emitting device, the lamp is fixed to a slide member that is slidably supported by the case. Further, a lever is connected to the slide member via a link mechanism, and a spring member is attached for positioning the slide member.

When one of the lamps becomes defective and the lamps are to be rearranged, the slide member is slid.

iii. In the conventional configuration, a link mechanism, a lever, and a spring member are required as dedicated members used to slide the slide member and rearrange the lamps. Therefore, in the conventional configuration, the structure becomes complicated and the manufacturing cost inevitably increases.

An object of the present invention is to provide a light emitting device for an overhead projector that has a simple structure and can reduce manufacturing costs.

[Means to solve the problem]

A light emitting device for an over-the-top projector according to the present invention includes a case, a pair of lamps arranged in the case, a condenser lens arranged on the irradiation side of the lamps, a slide member to which the lamps are fixed, and a case. and a spring member provided on the slide member.

The slide member is slidably supported by the case. The engagement means engage each other at a position where one of the lamps alternatively faces the condenser lens. Further, the spring member elastically urges the slide member in a direction in which the engaging means is in the engaged state,
It also serves as a knob for operating the slide member.

[Effect]

When rearranging the lamps in the light emitting device according to the present invention, the slide member is operated while grasping the spring member that also serves as a knob. At this time, the engaging means is once disengaged against the spring force of the spring member, and the slide member is slid. Then, at a position where another lamp faces the condenser lens, the engaging means is engaged based on the spring force of the spring member.

In this manner, in the present invention, since the spring member also serves as a knob, the structure is simplified and the light emitting device can be manufactured at low cost.

[Embodiment] FIG. 1 is a schematic perspective view of an overhead projector employing an embodiment of the present invention. In the figure, the overhead projector includes a base L for placing a document, a bed 2 placed above the base I, and a stay 3 that stands up from the base 1 so as to support the head 2 from below. There is.

The base 1 is a molded product made of resin, and has a space 4 therein for housing the head 2 and the stay 3, as shown in FIG. A flat plate-shaped M5 is placed on the upper end of the base 1. A Fresnel lens 6 is fixed to the top surface of the lid 5. A notch 7 is provided in the sliding member of the lid 5, and the stay 3 is fitted into the notch 7.

The head 2 has a case 10 mainly made of resin. Inside the case 10, there is a base side (stay 3 side)
A light emitting device 12 having an air blower II is housed therein, and a projection device I3 disposed in front of the light emitting device 12 is housed. Further, the blower device 11 includes a fan (not shown) and a motor that rotates the fan. The light emitting device 12 has a lamp 14 placed in the center thereof, a condenser lens 15 placed below the lamp 14, and a reflection plate 16 placed above the lamp 14.

The projection device 13 includes a projection lens 17 that receives reflected light from the base 1 and a projection mirror 18 arranged above the projection lens 17. The projection lens 17 has a focus adjustment function. Further, the projection mirror 18 has its base rotatably supported by the case 10 and can rotate around a support shaft 19 .

The lower part of the case 10 is a sheet metal mold, and the head 2 from which the resin portion of the case IO is removed is as shown in FIG. 3. As shown in FIG. 3, a pair of lamps 14 are provided including a spare lamp. The base of the lamp I4 is fixed to the slide member 21. The slide member 21 is slidably supported by a rod 22 extending in the left-right direction of the head 2 .

Both ends of the rod 22 are fixed to the case 10 side. A torsion spring 23 is fitted into the rod 22 inside the slide member 2. One end of the torsion spring 23 is
It is fixed to the slide member 21 using screws 24.

The other end of the torsion spring 23 is connected to the vertical wall 10 of the case 10, which is located further forward than the slide member 21 (to the right in FIG. 4).
It is elastically pressed against a. As a result, the torsion spring 23
This means that the lamp 14 is urged downward by the spring force. Furthermore, one end of the torsion spring 23 protrudes upward at the center of the upper end of the slide member 21, and this constitutes a knob 25 that stands upward from the base side of the slide member 21.

This knob 25 protrudes in the - direction from the projection device 13 side extension part 16a of the reflection plate 16, and its -F end is curved downward.

A switch 26 is arranged in the case 10 below the slide member 21. This switch 26 is switched based on a change in the position of the slide member 21 so that only the lamp 14 of the pair of lamps 14 disposed on the condenser lens 15 can be energized. Also,
A convex portion 27 that projects downward is provided at the lower end of the end of the slide member 2I on the lamp 14 side. This convex portion 27 is for positioning the slide member 21 in the extending direction of the rod 22, as will be described later.

A condenser lens 15 placed below the lamp 14 is fixed to a holding plate 20 provided at the bottom of the case 10. A pair of positioning holes 28 are formed in the holding plate 20 at the outer periphery of the condenser lens 15 .

As is clear from FIGS. 5 and 6 showing the moving posture of the slide member 21, a pair of holes 28 are provided at intervals in the left-right direction of the head 2 (vertical direction in the figure). When the convex portion 27 (FIG. 4) of the slide member 21 fits into one of the holes 28, the center of one lamp 14 and the optical axis of the condenser lens 15 coincide.

As shown in FIG. 4, the reflector 16 includes a spherical portion, portions extending downward on both sides thereof, and the above-mentioned extension portion 1.
6a. This reflecting plate 16 is connected to the supporting member 30
It is fixed to the lower surface of 131 via. 1i31 is
It is a member made of resin, and has a protrusion 32 provided on the base side of the head 2 and a spring member 33 provided on the tip side. Therefore, the protrusion 32 is locked to the case 10 side,
The lid 31 can be fixed to the upper part of the case 10 by press-fitting the spring member 33 into the hole 34 of the vertical wall 10a.

When the lid 31 is fixed to the upper part of the case 10, the knob 2 of the slide member 21 is lower than the extension 16a of the reflector 16.
5 protrudes upward. On the other hand, at a position corresponding to the knob 25, the extension portion 16a is provided with a notch 35 as shown in FIG. A pair of notches 35 are provided at intervals in the left-right direction of the head 2 (vertical direction in FIG. 7). That is, both notches 35 are provided corresponding to the position where the knob 25 is arranged at the fixed position of the slide member 21 shown in FIGS. 5 and 6.

Below the condenser lens 15, a large diameter hole 10 is provided in the case 10 in a portion corresponding to the condenser lens 15.
b is formed. Further, as shown in FIG. 8, on the base side of the head 2, an air intake port 40 is provided in the side wall of the case 10 facing the air blower 11. Further, a large number of ventilation holes 41 are formed in the partition wall between the blower device 11 and the chamber housing the lamp 14 and the like. Furthermore, the lower part of the holding plate 20, the light emitting device 12, and the projection device 1
There are discharge ports 42.4 at the lower part of the partition wall between the
3 is provided.

When using the above-mentioned Overherad projector, a transparent resin original is placed on the Fresnel lens 6 of the base 1 shown in FIG. Then, when the - lamp 14 is turned on, the light from the lamp 14 is passed through the condenser lens 15.
The reflected light passes through the document and reaches the projection lens 17. Further, the reflected light is reflected by a projection mirror I8, and an image of the original is projected onto a screen (not shown).

When the lamp 14 is turned on, it generates heat, so the blower device 11 is driven. When a fan (not shown) of the blower 11 rotates, outside air is guided from the air intake port 40 to the case 10 (FIG. 8). The cooling air from the blower 11 passes through the ventilation opening 41 and reaches the room where the lamp 14 and the like are housed. The cooling air cools each part including the lamp 14, and then is discharged downward from the discharge ports 42, 43. The air flow in this case is schematically shown by arrows in FIG. Here, no openings for discharging cooling air are provided at the upper end of the case 10 including I31, and discharge ports 42 and 43 are provided at the bottom of the case 10. In other words, since the configuration is such that the cooling air is discharged downward, even if the cooling air is warmed and lightened by the heat generated by the lamp 14, it is easily discharged outside before the cooling air has a sufficient cooling effect. This will prevent things from happening. Therefore, according to this configuration, the inside of the case 10 can be efficiently and widely cooled.

When the use of the Overherad projector is finished, the lamp 14 is turned off. Along with this, the supply of cooling air by the blower device 11 is also stopped. Even during the stop period of the Overhead Rad projector, since no opening for discharging cooling air is provided at the upper end of the case 10 including the lid 31, foreign matter will not enter the case from the -L direction through the opening. Therefore, even if the head 2 is left for a long period of time without being housed in the space 4 of the base 1, the inside of the case 10 will be less contaminated.

If one of the lamps 14 becomes defective during use of the OVERERAD projector, the OVERERADO projector is stopped and the lid 31 is lifted upward as shown by the solid line in FIG. 4 to open it. Furthermore, turn knob 25,
The slide member 21 is rotated against the torsion spring 23. As a result, the convex portion 27 is pulled out from the hole 28 of the holding plate 20.

Furthermore, the slide member 21 is slid in the left-right direction of the head 2 using the knob 25, and another lamp 14 is placed at the optical axis position of the condenser lens 15. Then, when the user releases the knob 25, the slide member 21 is rotated by the torsion spring 23, and the convex portion 27 is fitted into another hole 28. By the engagement of the convex portion 27 and the hole 28, the lamp 14
positioning is performed accurately. If this positioning is inaccurate, the lid 31 cannot be closed because the knob 25 does not match the notch 35 of the reflector 16.

This can prevent incorrect setting of the lamp 14. Also, since the position of the slide member 21 changes as the lamp 14 moves, the changeover switch 2
6 is switched. As a result, only the one located at the center of the condenser lens 15 among the pair of lamps 14 can be energized.

In addition, in the use state, the knob 25 is arranged above the extension part 16a of the reflection plate 16 through the notch 35. Therefore, heating of the knob 25 by the lamp 14 is suppressed. Therefore, when a failure occurs in the lamp 14,
Even immediately after the lamp 14 is turned off, the knob 25 can be easily operated with a finger.

Note that the present invention may be employed in a light-emitting device for a transmission type over-the-top projector.

(Effects of the Invention) In the light emitting device for an over-radiation projector according to the present invention, the spring member also serves as the tab b for operating the slide member, so the structure is simplified and the light emitting device can be manufactured at low cost. It becomes like this.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an overhead projector employing an embodiment of the present invention, FIG. 2 is a schematic longitudinal cross-sectional view thereof, FIG. 3 is a perspective partial view of the head with the case removed, and FIG.
The figure is an enlarged partial view of Figure 2, Figures 5 and 6 are partial plan views showing different operating states, and Figure 7 is a partial view of Figure 4.
(2) Partial cross-sectional view, FIG. 8 is a partial vertical cross-sectional view showing the air blowing state. 2... Head, 10... Case, 12... Light emitting device, 14... Lamp, 15... Condenser lens,
21... Slide member, 23... Torsion spring, 25
...Knob, 27...Protrusion, 28...Hole.

Claims (1)

[Claims] (1) A case, a pair of lamps arranged in the case, a condenser lens arranged on the irradiation side of the lamps, and a slide member slidably supported by the case and to which the lamps are fixed. , an engagement means provided between the case and the slide member that engages with each other at a position where one of the lamps alternatively faces a condenser lens; and the engagement means are in an engaged state. a spring member provided on the slide member that elastically urges the slide member in a direction, the spring member also serving as a knob for operating the slide member. .