JPS6291927A - Overhead projector - Google Patents

Abstract

PURPOSE:To eliminate troubles of turning or and turning off an illuminating lamp switch each time when picture projection is interrupted, by controlling the indoor illumination in accordance with a lighting switch for picture projection. CONSTITUTION:Two fixed pieces 18 and 19 and a mobile piece 21 which is normally brought into contact with them are arranged in an interlocking input part 5. Two fixed pieces 18 and 19 are connected to a part placed in the power source side of a power line 1A for illumination and a part placed in the illuminating lamp side respectively. Consequently, when an insertion part 17 is inserted to the interlocking input part 5, the mobile piece 21 is moved by a projection provided on the insertion part 17 and is separated from fixed pieces 18 and 19. Simultaneously, end parts of two connection cords 13 and 14 are brought into contact with corresponding fixed pieces 18 and 19. Thus, an illuminating lamp 6 is lit if a lighting switch 9 is turned off when an illuminating lamp switch 4 is turned on. If the lighting switch 9 is turned on when the illuminating lamp switch 4 is turned on, the illuminating lamp 6 is extinguished.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an overhead projector.

[Conventional technology]

Overhead projectors (hereinafter referred to as OHPs), which magnify and project a manuscript consisting of diagrams displayed on a transparent sheet onto a screen, are widely used as a visual display means during presentations and lectures at conferences, for example. ing.

By the way, when projecting an image using an OHP, the indoor lighting is usually dimmed. This is so that sufficient contrast can be obtained for the image on the screen. Therefore, when projecting an image using an OHP, (1) turn on the lamp for image projection by operating the lighting switch located on the projector body, and (2) turn on the lamp for projecting the image before or after this. By operating the light switch in the conference room, etc., all or part of the light is turned off.

When the image projection is finished, the operation opposite to the above operation is required.

[Problem that the invention seeks to solve]

For convenience of explanation, such operations will be repeated every time the use of the OHP is interrupted.

Therefore, the user has to walk to the place where the light switch is located each time, which is cumbersome. Particularly when the lighting switch is located far from the location where the OHP is installed, there is a problem in that it places an excessive burden on the user.

SUMMARY OF THE INVENTION An object of the present invention is to provide an overhead projector that can control indoor lighting without having to operate a lighting switch each time.

[Means for solving problems]

In the present invention, the OHP is provided with indoor lighting control means. This indoor lighting control means operates in conjunction with a lighting switch for controlling on/off lighting of a lamp for image projection,
Controls indoor lighting.

The indoor lighting control means preferably includes a switch that is connected in series with the lighting switch for the indoor lighting and operates in conjunction with the lighting switch for projecting the document.

〔Example〕

The present invention will be described in detail below with reference to Examples.

The drawing shows an outline of the wiring in a room in which the OHP of the present invention is installed. A pair of commercial power lines 1.2 is 2
It branches into two and is drawn into this room. Among these, the power lines IA and 2A are used for lighting, and the power lines IB and 2B are used for electrical appliances such as 0HP3.

One power supply line IA for illumination is connected to one power input terminal of each of the plurality of illumination lights 6 via the illumination light switch 4 and the interlocking human power unit 5 connected in series. The other power supply line IB for illumination is connected to the other power input terminal of the plurality of illumination lights 6. Power supply lines IB and 2B for electric appliances are connected to a recessed outlet 7 embedded in the wall, and connected to 0HP3 through this.

A lamp 8 for image projection is provided inside the main body of the OHP 3. The lighting of the lamp 8 is controlled to be turned on and off by operating a lighting switch 9 arranged at the top of the main body.

An interlocking output section 12 that moves the movable piece 11 in conjunction with the lighting switch 9 is arranged inside the main body of the 014P3. The movable piece 11 comes into contact with the fixed piece 15.16 attached to one end of the two connection cords 13.14, respectively, when the lighting switch 9 is turned off. This brings these connecting cords 13, 14 into electrical contact. In addition, when the lighting switch 9 is turned on, it is in a non-contact state with the fixed pieces 15 and 16, and the two connecting cords 1
3.14 will be electrically isolated.

Of these two connection cords 13 and 14, interlocking output section 1
The portion extended from 2 has a length sufficient to reach the interlocking human power section 5. This code part is OHP3
It is designed to be stored inside the main body when not in use, but when it is time to use it, it is pulled out and
An insertion part 17 attached to the tip thereof is inserted into the interlocking human power part 5.

By the way, the interlocking human power unit 5 is provided with two fixed pieces 18 and 19 and a movable piece 21 that is in constant contact with these pieces. The two fixing pieces 18 and 19 are respectively connected to a portion of the illumination power supply line IA located on the power supply side and a portion located on the lighting lamp side. Therefore, when the insertion part 17 is not inserted into the interlocking human power part 5, the illumination light 6 is turned on or off in accordance with the on/off operation of the illumination light switch 4. This is how the lighting in this room is controlled when the OHP 3 is not in use.

When the insertion part 17 is inserted into the interlocking input part 5, the movable piece 21 is moved by a projection (not shown) provided on the insertion part 17, and is brought into a non-contact state with the fixed pieces 18 and 19. At the same time, the ends of the two connecting cords 13.14 come into contact with the corresponding fixing pieces 18.19. This results in
When the lighting switch 9 is turned off while the illumination light switch 4 is on, the illumination light 6 is turned on. Further, when the lighting switch 9 is turned on in this state where the illumination light switch 4 is on, the illumination light 6 is turned off.

That is, in the present invention, the OHP user performs the following operations.

First, the OHP user turns on the illumination light switch 4 (the illumination light 6 is on), pulls out the two connection cords 13 and 14 from inside the OHP 3, and inserts the insertion part 17 into the interlocking human power part 5. Insert it into the Since the lighting switch 9 of 0HP3 is off at this time, the lighting lamp 6 remains lit.

Thereafter, when the user sets the original on the OHP 3 and turns on the lighting switch 9, the movable piece 11 moves away from the fixed pieces 15 and 16 in conjunction with this, and the illumination light 6 turns off. The room becomes dark, and the image of the original is clearly projected onto the screen. Thereafter, when the user turns off the lighting switch 9 to turn off the lamp 8, the lighting lamp 6 is turned on in conjunction with this. In this way, the user can switch the light switch 4
It is possible to control the lighting of lighting lights without having to operate them one by one.

In the embodiment described above, all the lighting lights in the room are controlled to blink, but only some of the lighting lights that interfere with projection may be controlled to blink.

Also, in this embodiment, a connection cord was used to link the blinking timing of the OHP lamp and the lighting in the room, but similar control can be performed without the need for a connection cord by using ultrasonic waves, radio waves, or special light beams. It is also possible.

〔Effect of the invention〕

As described above, according to the present invention, since the indoor lighting is controlled in conjunction with the lighting switch for image projection, there is no need to turn off and on the lighting switch every time image projection is interrupted. progress smoothly.

[Brief explanation of drawings]

The drawing is an indoor wiring diagram using an OHP according to an embodiment of the present invention. 1.2...Power line, 3...OHP. 4... Lighting light switch, 5... Interlocking human power section, 6... Lighting light, 8... Lamp, 9... Lighting switch , 12... Interlocking output section, 13.14... Connection code. Applicant: NEC Corporation

Claims (1)

[Claims] 1. A lamp for image projection and turning on/off this lamp.
a lighting switch for off-control; and an indoor light that operates in conjunction with the lighting switch to turn off at least a part of the lighting lamp provided for illuminating the room in which the image is projected when the lamp is turned on. An overhead projector comprising a control means. 2. A patent characterized in that the indoor lighting control means includes a switch that is connected in series with a lighting switch and operates in conjunction with the lighting switch for manually controlling the lighting of the lighting on and off. An overhead projector according to claim 1.