JPH03212636A - Overhead projector - Google Patents

Abstract

PURPOSE:To easily and rapidly perform the assembling of a condenser lens by providing a louver for fixing the condenser lens and a leaf spring in a case. CONSTITUTION:The condenser lens 15 is fixed on a holding plate 20 where the louvers 23 and 24 in which the edge part of the lens 15 is inserted and the attachable/detachable leaf spring 25 which can elastically press the edge part are formed in the case 10 of an overhead projector. At the time of assembling the lens 15, the lens 15 is fitted in the recessed part of the holding plate 20 and the outer periphery of the lens 15 is held by the louvers 23 and 24. Next, the leaf spring 25 is clamped to holding plate 20 by using a bolt 26 so as to fix the lens 15 on the holding plate 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an overherad projector, and in particular to an overherad projector having a condenser lens.

C. Prior Art] -C, an overherad projector has a base on which a translucent original is placed, and a head disposed above the base. The head includes a light emitting section having a lamp and a condenser lens, a projection section having a projection lens and a projection mirror, and a case that houses them.

In the light emitting section placed inside the case, a condenser lens is placed below the lamp. This condenser lens is fixed to the case by leaf springs provided at three positions at equal intervals in the circumferential direction of the lens. This leaf spring has its base fixed by a bolt, and its free end elastically presses against the edge of the condenser lens to hold the lens. When fixing the condenser lens to the case during assembly, first place the condenser lens at a predetermined position on the bottom surface of the case. Then, the condenser lens is fixed to the case by fixing the temporary spring with three bolts.

[Problem to be solved by the invention]

In the conventional configuration, when fixing the condenser lens with the leaf springs, any one of the three leaf springs is first temporarily fixed. At this time, due to the tightening of the leaf spring, a force is generated that biases the condenser lens and tends to shift it from a predetermined position. Therefore, when fixing the condenser lens, it is necessary to proceed while suppressing the force that tends to cause the lens to shift, and it is not easy to fix the condenser lens in an accurate position.

Further, the conventional configuration requires three leaf springs and three bolts, that is, many small independent parts, which not only increases the working time but also increases the manufacturing cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide an over-rad projector in which a condenser lens can be assembled easily and quickly, and which can be manufactured at low cost.

[Means to solve the problem]

The Overherad projector according to the present invention includes a light emitting unit housed in a case and having a lamp and a condenser lens. The case has a cutout into which the edge of the condenser lens can be inserted, and a removable leaf spring that can elastically press the edge of the condenser lens, in order to fix the condenser lens.

[Effect]

When assembling a condenser lens to the over-the-top projector according to the present invention, first insert the edge of the condenser lens into the cut-and-raised position. In this case, since the condenser lens is supported by a cut-and-raised part instead of a leaf spring, no force is generated to displace the condenser lens, and the condenser lens can be placed at an accurate position. Next, the edge of the condenser lens is elastically pressed by the leaf spring. This fixes the condenser lens to the case.

Although the condenser lens is elastically biased by this leaf spring, the load is borne by the cut and raised portions, so that the lens does not shift due to the pressing force of this leaf spring.

Here, since the number of independent parts required to fix the condenser lens is small and can be easily assembled, it can be manufactured at low cost.

[Embodiment] FIG. 5 is a schematic perspective view of an over-herad projector employing an embodiment of the present invention. In the figure, the Overherad 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 to support the head 2 from below. ing.

The base 1 is a molded product made of resin, and has a space 4 therein for accommodating 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 stay 3 side portion 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 blower section 11, a light emitting section 12, and a projection section 13 are housed in this order. The blower section 11 includes a fan (not shown) and a motor that rotates the fan. Light emitting part 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 it. The projection unit 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 .

In the light emitting unit 12, the condenser lens 15 is attached to a holding plate 20 provided at the bottom of the case 10, as shown in FIG.
Fixed. As shown in FIGS. 2 and 3, the holding plate 20 has an upwardly recessed circular recess 21 into which the condenser lens 15 can be fitted. The outer diameter of the upper end wall of the recess 21 is approximately the same as the outer diameter of the condenser lens 15.

A hole 22 having a diameter slightly smaller than the outer diameter of the condenser lens 15 is formed in the center of the recess 21 . Further, on the outer peripheral edge of the recessed portion 21, two cut-and-raised portions 23 and 24 and a temporary spring 25 are arranged at equal intervals in the circumferential direction. The cut and raised portions 23 and 24 are cut and raised so as to extend diagonally downward along the lower surface of the condenser lens 15, as shown in FIG.

Therefore, the outer periphery of the lower surface (convex surface) of the condenser lens 15 disposed in the recess 21 is cut and raised and pressed against the upper surface of the condenser lens 15 at 23°24. The leaf spring 25 has its base connected to the bolt 26.
It is fixed to the holding plate 20 by. In the portion corresponding to the leaf spring 25, the retaining plate 20 has a female screw 27 (third
) is formed, and a bolt 26 is screwed into the female thread 27 thereof. The free end of the leaf spring 25 extends diagonally downward from the bolt 26 along the lower surface of the condenser lens 15. Therefore, the leaf spring 25 is elastically pressed against the outer periphery of the lower surface of the condenser lens 15 fitted into the recess 21. As shown in FIG. 4, a pair of projections 28 projecting downward are formed on the retaining plate 20 on both sides of the bolt 26. This protrusion 28 is provided to stabilize the posture of the leaf spring 25.
This is a positioning protrusion for 5.

When using the above-mentioned Overherad projector,
An original made of transparent resin is placed on the Fresnel lens 6 of the Haas l. Then, if the lamp 14 is turned on, the lamp 14
The light passes through the condenser lens 15 and is reflected by the Fresnel lens 6, and the reflected light passes through the original 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).

Next, the assembly of the condenser lens 15 in the manufacturing process of this Over Rad projector will be explained.

The condenser lens 15 is fitted into the holding plate 20 in which a concave portion 21, a cut-out 23° 24, etc. are formed in advance. In this case, since the leaf spring 25 has not been set yet,
The condenser lens 15 is fitted into the recess 21 by sliding it from the protrusion 28 side to the cut and raised sides 23 and 24. As a result, the outer peripheral edge of the condenser lens 15 is held by the pair of cut and raised portions 23 and 24. Next, the leaf spring 25 is fixed to the retaining plate 20 with bolts 26. bolt 26
When tightened, the free end of the leaf spring 25 elastically presses the condenser lens 15, thereby fixing the condenser lens 15 to the holding plate 20.

In this case, when fitting the condenser lens 15 into the recess 21, the cut-and-raised 23° 24 is used as a rest instead of a leaf spring, so that the condenser lens 15 is placed in an accurate position.
can be placed. Also, when the plate spring 25 is pressed against the condenser lens 15 by tightening the bolt 26, the condenser lens is cut and raised 23.24.
Since it is supported from the opposite side by the condenser lens 15, the position of the condenser lens 15 will not shift. Furthermore, in this case, the condenser lens 15 can be fixed by simply tightening the bolt 26 at one location, so the work can be done easily and quickly.

Note that when implementing the present invention, the number of cut and raised portions and leaf springs can be set as appropriate. Further, the present invention can be similarly applied to a transmission-type over-herad projector.

[Effects of the Invention] Since the case of the overherad projector according to the present invention has a cut-and-raised portion and a leaf spring, the condenser lens can be assembled easily and quickly. Also,
Since there are fewer independent parts, it can be manufactured at a lower cost.

[Brief explanation of drawings]

FIG. 1 is a partial bottom view of an embodiment of the present invention, FIG.
Figures 1 and 4 are cross-sectional views taken along ■-■ and nt-
FIG. 5 is a perspective view of the Overherad projector according to the embodiment, and FIG. 6 is a schematic vertical cross-sectional view thereof. 2... Head, 10... Case, 12... Light emitting section, 13... Projection section, 14... Lamp, 15... Condenser lens, 17... Projection lens, 18... Projection mirror, 20... Holding plate, 23.24... Cut and raise, 25... Leaf spring. ] Figure Figure

Claims (1)

[Claims] (1) In an overhead projector that is housed in a case and has a light emitting unit that includes a lamp and a condenser lens, the case has a cutout into which an edge of the condenser lens can be inserted in order to fix the condenser lens. Wake up and
An overhead projector comprising a detachable leaf spring capable of elastically pressing an edge of the condenser lens.