JPH03214140A - Light emitting device for overhead projector - Google Patents

Abstract

PURPOSE:To suppress the rise of a temperature at a part which is used when a lamp is operated with the aid of simple structure by making a knob project upward from a reflecting plate and providing a chamfer to the position of the reflecting plate corresponding to the knob. CONSTITUTION:A pair of knobs 25 standing upward from the base side of a slide member 21 is provided to the center of the upper end of the member 21 and the knobs 25 project upward from an extension part 16a on the projection device 13 side of the reflecting plate 16. Besides, both chamfers 35 are provided at the fixing position of the slide member 21 corresponding to positions where the knobs 25 are arranged. Therefore, when the lamp 14 is lighted and the temperature of members arranged around the lamp rises, th heat of the lamp 14 is intercepted by the reflecting plate 16 and it hardly arrives at the knobs 25. Thus, the rise of the temperature of the knobs 25 is suppressed without adopting a complicated mechanism.

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.

The light emitting device disposed within the case is provided with a slidable slide member that supports the lamp and a lever connected to the slide member via a link mechanism. When the lamp is lit, the members arranged around the lamp also become hot, so a lever that is operated when moving the lamp is provided with a vertical partition wall in between. This results in
It is possible to suppress the temperature rise of the lever.

[Problem to be solved by the invention]

In the conventional light emitting device, a complicated link mechanism is essential to suppress the rise in temperature of the lever.

Therefore, the structure of that part becomes complicated, and manufacturing costs inevitably increase.

An object of the present invention is to provide a light-emitting device for a dobro dioctor that can suppress the temperature rise of the parts used when operating the lamp with a simple structure and that can be manufactured at low cost. be.

[Means to solve the problem]

A light emitting device for an overhead projector according to the present invention includes: a light emitting part having a lamp and a holding part that holds the lamp and is provided with a knob; a reflector disposed on the non-irradiation side of the light emitting part; It includes a condenser lens placed on the irradiation side. The knob protrudes above the reflector.

Further, the reflection plate has a notch at a position corresponding to the knob.

(Function) When the light emitting device for an overhead blower according to the present invention is used, the lamp is lit.

This increases the temperature of members placed around the lamp. However, the knob provided on the holding portion passes through the notch in the reflector and projects above the reflector. As a result, the heat from the lamp is blocked by the reflector, making it difficult for it to reach the knob. Therefore, according to this configuration, it is possible to suppress the temperature rise of the knob without employing a complicated mechanism.

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

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 lid 5 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 includes 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 11 is housed in the space, and a projection device 13 placed ahead 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. Furthermore, the light emitting device 12
is a lamp 14 arranged in the center, and a lamp 14
The condenser lens 15 and the lamp 1 arranged below the
4, and a reflecting plate 16 disposed above the reflector 4. The projection device 13 includes a projection lens 17 that receives reflected light from the base 1, and a projection mirror 18 disposed on the −L side of the projection lens 17.

The projection lens 17 has a focus adjustment function.

Further, the base of the projection mirror 18 is rotatably supported by the case IO, so that the projection mirror 18 can rotate around a support shaft 19.

The lower part of the case 10 is made of sheet metal, 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 14 is fixed to the slide member 21. The slide member 21 is a rod 2 extending in the left-right direction of the head 2 (vertical direction in FIG. 3).
It is slidably supported by 2. Both ends of the rod 22 are fixed to the case IO. Inside the slide member 21, a torsion spring 23 is fitted into the rod 22, as shown in FIG. One end of the torsion spring 23 is fixed to the slide member 21 using a screw 24. The other end of the torsion spring 23 is located further forward than the slide member 21 (
The vertical wall 10a of the case 10 is located on the right side of FIG.
It is elastically pressed against. As a result, the lamp 14 is urged downward by the spring force of the torsion spring 23. At the center of the F end of the slide member 21, a pair of knobs 25 are provided that stand upward from the base side of the slide member 21. This knob 25 protrudes above the projection device 13 side extension portion 16a of the reflection plate 16. A switch 26 is arranged in the case 10 below the slide member 21. This switch 26 switches between the pair of lamps 1 based on the change in the position of the slide member 21.
Out of the four condenser lenses 15'', only the lamp 14 disposed at the second condenser lens can be energized. Also,
A convex portion 27 that protrudes downward is provided at the lower end of the end of the slide member 21 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 (four portions) 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).

The convex portion 27 (the fourth
If the two lamps shown in the figure are fitted, the center of one of the lamps 14 and the optical axis of the condenser lens 15 will 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.
．． 6 a. This reflecting plate 16 is fixed to the lower surface of 131 via a support member 30. 131 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, by locking the protrusion 32 on the case 10 side and press-fitting the spring member 33 into the hole 34 of the vertical wall 10a, the 131 can be fixed to the F section of the case 10.

When the lid 31 is fixed to the upper part of the case 10, the knob 2 of the slide member 2I 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 ta is provided in the case IO in the portion corresponding to the condenser lens 15.
b is formed. Further, as shown in FIG. 8, an air intake port 40 is provided on the side wall of the case IO facing the blower 11 on the base side of the head 2. Further, a large number of ventilation holes 41 are formed in the partition wall between the ventilation device 111 and the chamber housing the lamp 14 and the like.

Furthermore, the lower part of the holding plate 20 and the lower part of the partition wall between the light emitting device 12 and the projection device 13 are provided with discharge l114, respectively.
2.43 is provided.

When using a double overhead projector, a transparent resin original is placed on the Fresnel lens 6 of the base 1 shown in FIG. Then, when the other lamp 14 is turned on, the light from the lamp 14 passes 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 the projection mirror 18, 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 into the case 10 from the air intake port 40 (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, an opening for discharging cooling air is not provided at the upper end of the case 10 including the lid 31, and discharge ports 42 and 43 are provided at the lower part of the case IO. 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 overhead projector is finished, the lamp 14 is turned off. Along with this, the supply of cooling air by the air blower 11 is also stopped. Even during the period when the overhead projector is stopped, the upper end of the case 10 including the lid 31 is not provided with an opening for discharging cooling air, so foreign matter will not enter the case from above through the opening. Therefore, even if the head 2 is left alone for a long period of time without being housed in the space 4 of the base 1, there is little dirt inside the case 10.

If one of the lamps 14 becomes defective during use of the overhead projector, the overhead projector is first stopped and the 1ff 31 is lifted upward and opened as shown by the solid line in FIG. Furthermore, the knob 25 is pinched to rotate the slide member 21 against the torsion spring 23. As a result, the protrusion 2 is removed from the hole 28 of the holding Fi 20.
7 is the winner.

Further, using the knob 25, the slide member 21 is slid in the left and right direction of the head 2, 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. Due to the engagement between the convex portion 27 and the hole 28, the lamp 1
4 positioning is performed accurately. If this positioning is inaccurate, the knob 25 will not match the notch 35 of the reflective plate 16, so 1j31 cannot be closed.

Contamination can prevent incorrect cents of the lamp 14. Further, as the lamp 14 moves, the position of the scoop 1' member 21 changes, so the changeover switch 26 is changed over. 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 use, the knob 25 is located above the extension 1.6a of the reflector 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, the knob 25 can be easily operated with a finger even immediately after the lamp 14 is turned off.

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

〔Effect of the invention〕

Since the light emitting device for an overhead projector according to the present invention employs the knob and notch as described above, the temperature of the knob does not increase much when switching the lamp, and the lamp can be switched quickly and easily. Switching can be performed. In addition, manufacturing is simple, and a light emitting device can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an overhead projector in which an embodiment of the present invention is adopted, Fig. 2 is a schematic vertical cross-sectional view thereof, Fig. 3 is a plan view of the head with the case removed, and Part 4 shows the second FIGS. 5 and 6 are enlarged partial views of FIG. 3, and FIG.
The figure is a partial cross-sectional view taken along the line ■-■ in FIG. 4, and FIG. 8 is a partial longitudinal cross-sectional view showing the air blowing state. 2... Head, I2... Light emitting device, 14... Lamp, 15... Condenser lens, 16... Reflector plate,
21...Slide member, 25...Knob, 35...
・Notch. Figure ＼ Figure 2 Figure Stone 5 Figure 3 Ma Figure

Claims (1)

[Claims] (1) A light-emitting part having a lamp, a holding part that holds the lamp and is provided with a knob, a reflector disposed on a non-irradiation side of the light-emission part, and a light-emitting part disposed on the irradiation side of the light-emission part. A light emitting device for an overhead projector, comprising: a condenser lens, wherein the knob protrudes above a reflecting plate, and the reflecting plate has a notch at a position corresponding to the knob.