A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen.
Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen.
The most common type of projector used today is called a video projector. Video projectors are digital replacements for earlier types of projectors such as slide projectors and overhead projectors. These earlier types of projectors were mostly replaced with digital video projectors throughout the 1990s and early 2000s (decade), but old analog projectors are still used some places. The newest types of projectors are handheld projectors that use lasers or LEDs to project images. Their projections are hard to see if there is too much ambient light.
Movie theaters use a type of projector called a movie projector. Another type of projector is the enlarger, a device used to produce photographic prints from negatives.
History of projectors
1832 Joseph Plateau and sons introduce the Phenakistoscope. Pictures on one disc viewed through slots in the other, appeared to move when the two were spun and viewed in a mirror.
The phenakistoscope – a couple waltzing
1834 The Zoetrope was introduced by William George Horner. The Zoetrope used the same principle as Plateau's Phenakistoscope but instead of discs the pictures and slots are combined in a rotating drum. Zoetrope's were widely sold after 1867.
1839 Henry Fox Talbot makes an important advancement in photograph production with the introduction of negatives on paper - as opposed to glass. Also around this time it became possible to print photographic images on glass slides which could be projected using magic lanterns.
1853 photo by Talbot
1877 Emile Reynaud introduces the Praxinoscope. Similar in design to Horner's Zoetrope, the illusion of movement produced by the Praxinoscope was viewed on mirrors in the centre of the drum rather than through slots on the outside.
An 1879 illustration of a praxinoscope
1878 Eadweard Muybridge achieves success after five years of trying to capture movement. Muybridge was asked, in 1873, by the ex-governor of California - Leland Stanford to settle a bet as to whether horses hooves left the ground when they galloped. He did this by setting up a bank of twelve cameras with trip-wires connected to their shutters, each camera took a picture when the horse tripped its wire. Muybridge developed a projector to present his finding. He adapted Horner's Zoetrope to produce his Zoopraxinoscope.
Zoopraxiscope disc by Eadweard Muybridge
Simulation of a spinning zoopraxiscope
Marey's photographic gun
1882 Emile Reynaud expands on his praxinoscope and using mirrors and a lantern is about to project moving drawings onto a screen.Charles-Émile Reynaud (8 December 1844 – 9 January 1918) was a French inventor, responsible for the first projected animated cartoons. Reynaud created the Praxinoscope in 1877 and the Théâtre Optique in December 1888, and on 28 October 1892 he projected the first animated film in public, Pauvre Pierrot, at the Musée Grévin in Paris. This is also notable as the first known instance of film perforations being used.
Reynaud and his Théâtre Optique in 1892
Reynaud and his Théâtre Optique in 1892
1888 Etienne Marey builds a box type moving picture camera which uses an intermittent mechanism and strips of paper film.
1888 Thomas A. Edison, inventor of the electric light bulb and the phonograph decides to design machines for making and showing moving pictures. With his assistant W.K.L Dickson (who did most of the work), Edison began experimenting with adapting the phonograph and tried in vain to make rows of tiny photographs on similar cylinders.
1889 Edison travels to Paris and views Marey's camera which uses flexible film. Dickson then acquires some Eastman Kodak film stock and begins work on a new type of machine.
1891 By 1891, Edison and Dickson have their Kinetograph camera and Kinetoscope viewing box ready for patenting and demonstration. Using Eastman film cut into inch wide strips, Dickson punched four holes in either side of each frame allowing toothed gears to pull the film through the camera.
Interior view of Kinetoscope with peephole viewer at top of cabinet
The 1895 version of the Kinetophone in use, showing the earphones that lead to the cylinder phonograph within the cabinet
1892 Using his projecting Praxinoscope, Reynaud holds the first public exhibitions of motion pictures. Reynaud's device was successful, using long strips of hand-painted frames, but the effect was jerky and slow.
1893 Edison and Dickson build a studio on the grounds of Edison's laboratories in New Jersey, to produce films for their kinetoscope. The Black Maria was ready for film production at the end of January.
In 1895 two inventors, Charles Jenkins and Thomas Armat invented a motion picture projector which they named the Phantoscope. Thomas Edison became interested in the new projector and agreed to manufacture it and produce films for it through his company (The Edison Manufacturing Company), provided he be credited with the invention of the projector. Edison renamed the projector the Vitascope.
Vitascope Invention Used in First Movie Theatres
1895 The Lathams too had succeeded in creating a camera and a projector and on April 21st 1895 they showed one film to reporters. In May they opened a small storefront theatre. Their projector received only a small amount of attention as the image projected was very dim. The Lathams did however contribute greatly to motion picture history. Their projectors employed a system which looped the film making it less susceptible to breaks and tears. The Latham Loop as it was dubbed later is still in use in modern motion picture projectors.
1896 Early in 1896, Herman Casler and W.K.L Dickson had developed their camera to go with Casler's Mutoscope. However the market for peepshow devices was in decine and they decided to concentrate on producing a projection system. The camera and projector they produced were unusual as they used 70mm film which gave very clear images.
Mutoscope in San Francisco antique arcade
1896 The Lumière brothers sent a representative from their company to London and started a successful run of Cinématographe films.
1897 By 1897 the American Mutoscope Company become the most popular film company in America - both projecting films and with the peephole Mutoscope which was considered more reliable than the kinetoscope.
1899 The American Mutoscope Company changes its name to the American Mutoscope and Biograph Company to include its projection and peepshow devices.
1903 British film maker George Smith makes Mary Janes Mishap which was praised for its sophisticated use of editing. The film uses medium close-ups to draw the viewers attention to the scene, juxtaposed with wide establishing shots. The film also contains a pair of wipes which signal a scene change.
1903 The American Mutoscope and Biograph Company begin making films in the 35mm format rather that the 70mm which boosted their sales. The company went on to employ one of the most important silent film directors - D.W Griffith in 1908.
Early history of projectors and cameras
Projectors share a common history with cameras. As far back as the 4th century BC, Greeks such as Aristotle and Euclid wrote on naturally-occurring rudimentary pinhole cameras. For example, light may travel through the slits of wicker baskets or the crossing of tree leaves. (The circular dapples on a forest floor, actually pinhole images of the sun, can be seen to have a bite taken out of them during partial solar eclipses opposite to the position of the moon's actual occultation of the sun because of the inverting effect of pinhole lenses.)
It was the 10th-century Ibn al-Haytham (Alhazen), who published this idea in the Book of Optics in 1021. When Ibn al-Haytham began experimenting with the camera obscura, he himself stated, Et nos non inventimus ita, "we did not invent this". He improved on the camera after realizing that the smaller the pinhole, the sharper the image (though the less light). He provides the first clear description for construction of a camera obscura (Lat. dark chamber). As a side benefit of his invention, he was credited with being first man to shift physics from a philosophical to an experimental basis.
In the 5th century BC, the Mohist philosopher Mo Jing (墨經) in ancient China mentioned the effect of an inverted image forming through a pinhole. The image of an inverted Chinese pagoda is mentioned in Duan Chengshi's (died 863) book Miscellaneous Morsels from Youyang written during the Tang Dynasty (618–907). Along with experimenting with the pinhole camera and the burning mirror of the ancient Mohists, the Song Dynasty (960–1279) Chinese scientist Shen Kuo (1031–1095) experimented with camera obscura and was the first to establish geometrical and quantitative attributes for it.
In the 13th century, Robert Grosseteste and Roger Bacon commented on the pinhole camera.Between 1000 and 1600, men such as Ibn al-Haytham, Gemma Frisius, and Giambattista della Porta wrote on the pinhole camera, explaining why the images are upside down. Pinhole devices provide safety for the eyes when viewing solar eclipses because the event is observed indirectly, the diminished intensity of the pinhole image being harmless compared with the full glare of the Sun itself.
The first image projectors
The first known record of what might portray the idea of projecting an image on a surface is a drawing by Johannes de Fontana from 1420. The drawing was of a nun holding something that might be a lantern. The lantern had a small translucent window that contained an image of a devil holding a lance . Leonardo da Vinci also made a similar sketch in 1515. These drawings are likely to have inspired the creation of the earliest image projector, a device called a magic lantern.
In the 17th century, the first magic lantern was developed. With pinhole cameras and camera obscura it was only possible to project an image of actual scene, such as an image of the sun, on a surface. The magic lantern on the other hand could project a painted image on a surface, and marks the point where cameras and projectors became two different kinds of devices. There has been some debate about who the original inventor of the magic lantern is, but the most widely accepted theory is that Christiaan Huygens developed the original device in the late 1650s.
However, other sources give credit to the German priest Athanasius Kircher. He describes a device such as the magic lantern in his book Ars Magna Lucis et Umbrae. There are possible mentions of this device associated with Kircher as early as 1646. Even in its earliest use, it was demonstrated with monstrous images such as the Devil. Huygen’s device was even referred to as the “lantern of fright” because it was able to project spooky images that looked like apparitions. In its early development, it was mostly used by magicians and conjurers to project images, making them appear or disappear, transform from one scene into a different scene, animate normally inanimate objects, or even create the belief of bringing the dead back to life. In the 1660s, a man named Thomas Walgensten used his so-called “lantern of fear” to summon ghosts. These misuses of this early machine were not uncommon. In fact, a common setup of the machine was to keep parts of the projector in a separate, adjoining room with only the aperture visible, to make it seem more magical and scare people.
A 1960 slide projector
By the 18th century, use by charlatans was common for religious reasons. For example, Count Cagliostro used it to ‘raise dead spirits’ in Egyptian masonry. Johann Georg Schröpfer used the magic lantern to conjure up images of dead people on smoke. He staged routines doing this at his coffee shop in Leipzig. He did this to scare people and make them think he was a good actor. Schröpfer ended up going crazy and thinking he himself was pursued by real devils, and shot himself after promising an audience he would later resurrect himself.
The magic lantern or Laterna Magica is an early type of image projector developed in the 17th century.
The magic lantern used a concave mirror in back of a light source to direct as much of the light as possible through a small rectangular sheet of glass—a "lantern slide"—on which was the painted or photographic image to be projected, and onward into a lens at the front of the apparatus. The lens was adjusted to optimally focus the plane of the slide at the distance of the projection screen, which could be simply a white wall, and it therefore formed an enlarged image of the slide on the screen.
Apart from sunlight, the only light sources available at the time of invention in the 16th century were candles and oil lamps, which were very inefficient and produced very dim projected images. The invention of the Argand lamp in the 1790s helped to make the images brighter. The invention of limelight in the 1820s made them very much brighter. The invention of the intensely bright electric arc lamp in the 1860s eliminated the need for combustible gases or hazardous chemicals, and eventually the incandescent electric lamp further improved safety and convenience, although not brightness.
There has been some debate about who the original inventor of the magic lantern is, but the most widely accepted theory is that Christiaan Huygens developed the original device in the late 1650s. In the fifteenth century, however, Giovanni Fontana, a Venetian engineer, had already created a lantern that projected an image of a demon. And other sources give credit to the German priest Athanasius Kircher. He describes a device such as the magic lantern in his book Ars Magna Lucis et Umbrae.There are possible mentions of this device associated with Kircher as early as 1646. Even in its earliest use, it was demonstrated with monstrous images such as the Devil. Huygens's device was even referred to as the "lantern of fright" because it was able to project spooky images that looked like apparitions. In its early development, it was mostly used by magicians and conjurers to project images, making them appear or disappear, transform from one scene into a different scene, animate normally inanimate objects, or even create the belief of bringing the dead back to life.
In the 1660s, a man named Thomas Walgensten used his so-called "lantern of fear" to summon ghosts. Such uses of this early machine were not uncommon. In fact, a common setup of the machine was to keep parts of the projector in a separate, adjoining room with only the aperture visible, to make it seem more magical and scare people. By the 18th century, use by charlatans was common for religious reasons. For example, Count Cagliostro used it to "raise dead spirits" in Egyptian masonry. Johann Georg Schröpfer of Leipzig used the magic lantern to conjure up images of spirits on smoke. Schröpfer later went insane, thinking he was pursued by real devils, and shot himself after promising an audience he would later resurrect himself.