Optics: image projectors – Epidiascope – Plural reflectors between lamp and screen
Patent
1980-07-23
1982-08-10
Haroian, Harry N.
Optics: image projectors
Epidiascope
Plural reflectors between lamp and screen
353101, 353DIG4, 353 63, G03B 2108
Patent
active
043435386
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The invention refers to a projector comprising a substantially horizontal table, a projecting optics arranged substantially centrally above the table, a light source which is located above the table and arranged to illuminate the table, a deflexion mirror for substantially horizontal deflexion of light radiating vertically upwardly from the table, and a light shaft which at least partially screens off the area between the optics and the table from the environment.
BACKGROUND
Information activity is often conducted before small groups of e.g. around ten individuals or less. In connection with such information activity, projectors of so called over-head-type often come to use. Such a projector must i.a. due to the small size of the group, not be too complicated, heavy or expensive. Should moreover ready portability be a desire, the choice often falls on a so called 3 M projector. In order to project a picture material by means of such a projector, the material, however, must normally be transferred to so called large dias, which is a time-consuming and expensive measure even if the picture material should be of suitable large dia size, i.e. A4.
Problem of having to transfer the picture material into large dia or the like, has been noted and has partly been given a solution through e.g. Swedish Pat. No. 397 140, which thus constitutes an indication on the stand point of the technique. However, such an apparatus is i.a. not readily transportable and is not useful in connection with small groups.
OBJECT OF THE INVENTION
A primary object of the invention therefore is, starting from a simple large dia projector, to provide an easily transportable projector which with the purpose to be used before small groups and offer a moderate enlargement of the picture material, can project transparent picture material as well as non-transparent picture material without being structurally complicated. Another object of the inventive projector is to provide the possibility of an enlarged projection of small picture dia (e.g. 24.times.36 mm) or microfiche by means of the optics used in the projector.
Further objects of and purposes with the invention will appear in the following.
DISCLOSURE SUMMARY OF THE INVENTION
The inventive projector comprises a substantially horizontal table, projection optics arranged substantially centrally above the table, a light source which is located above the table and arranged to illuminate the table, a deflexion mirror for substantially horizontal deflexion of light radiating vertically upwardly from the table, and a light shaft which at least partially screens off the area between the optics and table from the environment, and is distinguished in that a covering is arranged layable over the surface of the table, and in that the upwardly facing surface of the laid out covering is light-reflecting, the surface of the table being light-absorbing, preferably mat and black, alternatively in that the upwardly facing surface of the laid out covering is light absorbing, the surface of the table being arranged to emit light vertically upwardly.
Thus, it has turned out that the projector design which is stated in the appended main claim, provides a simple switching between transparent and non-transparent picture material, and, furthermore, thanks to the light absorbing table covering for projection of a non-transparent picture material, offers a remarkably good and stray-light-free projected image.
In order to be easily handled, the covering can have the shape of a rollable foil, which is arranged rollable at a peripheral area of the table. The design can then be such that the foil is connected to a rotatably journaled and stationary roll up shaft at a margin area of the table, that the shaft is spring urged in order to permit rolling up of the foil on the shaft, and that the shaft preferably is provided with a roll up latch which is releasable by limited pulling of the foil in the roll out direction. The mirror may be pivotably or rotatably journaled in order to as desired perm
REFERENCES:
patent: 1176485 (1916-03-01), Ott
patent: 2596393 (1952-05-01), Fitzgerald
Asthausbolagen HB Astero & Stockhaus
Haroian Harry N.
LandOfFree
Projector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Projector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Projector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1529104