EP0293124A1 - Appareil d'exposition - Google Patents

Appareil d'exposition Download PDF

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Publication number
EP0293124A1
EP0293124A1 EP88304452A EP88304452A EP0293124A1 EP 0293124 A1 EP0293124 A1 EP 0293124A1 EP 88304452 A EP88304452 A EP 88304452A EP 88304452 A EP88304452 A EP 88304452A EP 0293124 A1 EP0293124 A1 EP 0293124A1
Authority
EP
European Patent Office
Prior art keywords
light
original
photosensitive material
modulation element
optical modulation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP88304452A
Other languages
German (de)
English (en)
Inventor
Taisuke Miyoshi
Jin Unayama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Instruments Inc
Original Assignee
Seiko Instruments Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiko Instruments Inc filed Critical Seiko Instruments Inc
Publication of EP0293124A1 publication Critical patent/EP0293124A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/04018—Image composition, e.g. adding or superposing informations on the original image
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material

Definitions

  • the present invention relates to apparatus for exposing photosensitive material.
  • the present invention provides an additional function of exposure control using electric signals by installing a reflection type optical modulation element where the original would be located.
  • Such apparatus is large in size and complicated in structure because, in addition to a section to expose photosensitive material to light reflected from the original, it has an exposure control section that uses electric signals and which consists of a light source, a light converging means and an optical modulation element. This drawback inevitably leads to other disadvantages of higher cost and larger power consumption.
  • this invention adds an exposure control function to the existing function of exposing the photosensitive material to reflected light from the original by simply adding to where the original is located a reflection type optical modulation element that has its reflectivity changed by electric signals.
  • apparatus for exposing photosensitive material in a copying machine comprising a light source to light an original to be copied and means to optically direct light reflected from the original onto the photosensitive material, is characterised by comprising a reflective type optical modulation element installed where the original would be, and means to change by electric signals the reflection characteristics of the element so as to control the exposure of the photosensitive material.
  • the invention is further characterised in that the reflective type optical modulation element is a liquid crystal device having transparent electrodes between which liquid crystal material is sandwiched, and to which electric signals are supplied by drive means.
  • the apparatus may be characterised in that there is a common electrode and a multiplicity of spaced individually energisable electrodes in a line across the path of light from the light source.
  • the invention may be characterised in that there is a common electrode and a multiplicity of spaced individually energisable electrodes in three lines across the path of light from the light source, the lines being provided with different colour filters, respectively.
  • the reflective type optical element may be a piezo-electric device in which piezo-electric material is sandwiched between a common electrode and a multiplicity of reflective plates which are individually energisable.
  • such an original is replaced by a reflection type optical modulation element 10 ( Figures 2 a and 2 b ), the reflection characteristics of which are changed by electric signals applied to transparent electrodes 13 and 14 between which liquid crystal material 15 is located.
  • the electrodes 13 and 14 are mounted on spaced transparent substrates 11 and 12, respectively with a reflective plate 16 on the outer face of the substrate 11.
  • a drive circuit 17 is connectible across the electrodes 13 and 14 to provide signals.
  • the electric signal is switched off ( Figure 2 a )
  • the incident light 1 either passes through the element 10 or is reflected by the plate 16 without reaching the photosensitive material 7.
  • the electric signal is on ( Figure 2 b )
  • the liquid crystal material 15 takes up such a disposition that the incident light 1 is scatter reflected before reaching the plate 16 and part of the scattered light 2 passes through the optical lens 5 and slit to expose the photosensitive material 7.
  • the reflection type optical modulation element 10 takes the form of a thin plate 19, piezo-electric device 18 and an electrode 20, the drive circuit 17 being connectible across the thin plate 19 and electrode 20 to provide electric signals to the piezo-electric device 18.
  • the electric signal when the electric signal is off ( Figure 3 a ) incident light is reflected by the plate 19 as light 2 to pass through the optical lens 5 and slit to expose the photosensitive material 7.
  • the piezo-electric device 18 deforms and changes the attitude of the plate 19 so that the direction in which the reflected light 2 travels is so changed that it will not pass through the lens 5 and exposure of the photosensitive material 7 is stopped.
  • exposure of the photosensitive material 7 is controlled.
  • an electrophotographic copying machine is used as a device to expose the photosensitive material to the reflected light from an original (such as text), and a scatter type liquid crystal device is used as the reflection type optical modulation element to be installed where an original would otherwise be located.
  • the electrophotographic copying machine includes an original support table 9 linearly movable over the top of the machine in correspondence with the rotation of the drum 7 of photosensitive material.
  • a light source 21 has a reflective element 22 by which light is incident upon an original carried by the table 9 in a thin band transverse to the direction of movement of the table. The incident light is then reflected or absorbed or reflected (as described above in reference to Figures 1 a and 1 b ) through the lens 5 and the slit between stops 6 onto the photosensitive material of the drum 7.
  • the surface of the drum has been charged by a charger 23, and thereafter toner 25 is applied to the surface of the drum.
  • a reflection type optical modulation element 10 is located in a stationary position to be able to reflect incident light from the source 21 onto the lens 5. Such position may necessitate the removal of the table 9, or the disablement of its movement.
  • the optical modulation element 10 takes the form of a liquid crystal device, similar to that shown in Figures 2 a and 2 b .
  • the device consists of two opposed and spaced transparent substrates 11 and 12 on which are formed transparent electrodes 13 and 14.
  • the transparent electrodes 13 ( Figure 5 a ) on the substrate 11 consist of separately energisable electrodes, of about 0.1mm width to give 240 electrodes per inch (25.4mm).
  • On the substrate 12 ( Figure 5 b ) is a single common transparent electrode 14.
  • a liquid crystal material 15 which is located between the electrodes and which has a dynamic dispersion effect on light is sealed between the substrates.
  • the transparent electrodes on the two opposing substrates are thus formed into a pattern consisting of a line of dots at a density of 240 dots per inch (25.4mm).
  • the liquid crystal section corresponding to each dot is separately electrically connected to the drive circuit 17 through the transparent electrodes 13 and the common electrode 14.
  • the electric voltage signals applied to the individual transparent electrodes 13 are selected to give the exposure to the photosensitive material which is required to achieve the copy desired, which may, for example, be a page of text and/or drawings. Such signals may conveniently be derived from data stored in a computer and delivered to the electrodes in accordance with instructions therefrom.
  • threshold value OFF
  • the incident light 1 Figure 2 a
  • the reflective plate 16 provided on the other side of the transparent substrate 11.
  • the reflected light 2 does not reach the optical lens 5, which may be a self-convergent rod lens array, so that the photosensitive material on the drum 7 is not exposed.
  • the layer of liquid crystal material 15 ( Figure 2 b )goes into a dynamically dispersing state and scatters the incident light 1.
  • a part of the reflected and scattered light 2 enters the optical lens 5 passing through the slit between the stops 6 and exposing the photosensitive material on the drum 7.
  • the liquid crystal layer By making the liquid crystal layer a few micrometers thick or less and setting the applied voltage at 10V to 20V, the liquid crystal can be driven to display the dynamic dispersion effect within a time of the order of milliseconds, thereby permitting the exposure of one text page of A4 size to be performed in a few seconds.
  • phase transfer type liquid crystal as the crystal liquid material 15 to be sealed in the crystal liquid device.
  • This type of crystal liquid layer can also be switched between transparent state and scatter state by controlling the applied voltage.
  • the use of the transparent and the scatter states of a strong dielectric crystal liquid enables exposure switching in a few 1 hundred microseconds.
  • the piezo-electric device uses the deformation in the crystal structure produced by voltage application to generate deflecting motion of the device.
  • the individual devices are about 0.1mm in width and there are 240 per inch (25.4mm).
  • the electrode 20 is common and the individual plates 19 are separately driven from the drive circuit 17.
  • Each thin plate 19 is of metal and doubles as an electrode and a mirror, having one side facing the incident light finished to form a mirror which, by the deflecting motion of the piezo-electric device 18, changes the path of the reflected light 2, as shown in Figures 2 a , and 2 b , thereby performing the exposure switching.
  • the drive frequency suited to the piezo-electric device is several kHz and switching is performed in a few hundred microseconds.
  • colour reproduction is possible.
  • an image of a first of three colours is reproduced upon the photosensitive material on the drum 7 and toner of the first colour is applied to the drum surface and transferred to paper.
  • the toned paper is passed through the machine or another one again, and an image of the second colour is reproduced upon the photosensitive material on the drum and toner of the second colour applied to be transferred to the paper.
  • the same steps are repeated with an image of the third colour and toner of the third colour, so that images of the three colours are superimposed to reproduce the full colour image.
  • images are reproduced by exposure of photosensitive material and subsequent application of toner, followed by transfer of toner and fixing on paper or other medium.
  • images are reproduced by exposure of photosensitive material in the form of sensitized paper or negative film, so that xerography is not involved.
  • a reflection type liquid crystal device is used as the reflection type optical modulation element 10, a fluorescent lamp as the light source 21 to light the reflection type liquid crystal device, and a self-convergent rod lens array as the optical lens 5, to radiate the reflected light from the reflection type liquid crystal device onto photosensitive paper 32, which is passed through the machine by supply rollers 27 and a conveyor belt 29.
  • the photosensitive paper 32 passes below the slit between the stops 6, where it is exposed to the reflected light radiated by the lens 5.
  • the second embodiment is particularly suitable for colour reproduction, in which case the two transparent electrodes on the two opposing transparent substrates of the liquid crystal device are combined to form a pattern consisting of three lines of dots at a density of 240 dots per inch (25.4mm).
  • the three lines of dots are provided with cyan (C), magenta (M) and yellow (Y) filters, respectively.
  • Colour photosensitive paper 32 is used and in synchronism with the movement of the photosensitive paper, the three lines of dots are switched between a transparent and scatter state.
  • a colour image is obtained by controlling the switching between the transparent and the scatter states of the dots in the lines and the photosensitive paper is passed through the machine only once. Subsequent to exposure, the paper is developed in a developer 24.
  • photosensitive material a negative film and a sensitized paper on which direct writing is possibly permitted and commonly used for photography, are satisfactory.
  • the present invention enables the addition of an exposure control function using electric signals simply by adding a reflection type optical modulation element to an apparatus which exposes photosensitive material to reflected light from an original to be copied.
  • the reflection type optical modulation element may be formed of the reflection type liquid crystal device or piezo-electric device and hence is small and light, and also consumes only a small amount of power. Because the light source and the light converging means are shared by the two functions, modification to existing apparatus when implementing this invention is not necessary or, if so, is only minor with small extra cost.
  • the invention allows a copying machine to be used as the printer of a computer and word processor, or as the output device of a facsimile machine. Not only does this widen the range of use of a copying machine, but also make it possible with small extra cost to integrate various kinds of equipment into a multi-purpose one.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Liquid Crystal (AREA)
  • Holders For Sensitive Materials And Originals (AREA)
  • Optical Systems Of Projection Type Copiers (AREA)
  • Control Of Exposure In Printing And Copying (AREA)
EP88304452A 1987-05-22 1988-05-17 Appareil d'exposition Withdrawn EP0293124A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP125160/87 1987-05-22
JP12516087A JPS63289544A (ja) 1987-05-22 1987-05-22 露光装置

Publications (1)

Publication Number Publication Date
EP0293124A1 true EP0293124A1 (fr) 1988-11-30

Family

ID=14903361

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88304452A Withdrawn EP0293124A1 (fr) 1987-05-22 1988-05-17 Appareil d'exposition

Country Status (2)

Country Link
EP (1) EP0293124A1 (fr)
JP (1) JPS63289544A (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5766453A (en) * 1980-10-14 1982-04-22 Ricoh Co Ltd Synthetic picture recorder
JPS57167057A (en) * 1981-04-07 1982-10-14 Seiko Epson Corp Optical printer
JPS6097370A (ja) * 1983-11-01 1985-05-31 Nec Corp 複写装置
JPS60103363A (ja) * 1983-11-10 1985-06-07 Konishiroku Photo Ind Co Ltd 複写装置
JPS60140221A (ja) * 1983-12-28 1985-07-25 Konishiroku Photo Ind Co Ltd 付加情報記録装置
EP0251617A2 (fr) * 1986-06-23 1988-01-07 Xerox Corporation Appareil de formation d'images à modes d'exploitation multiples

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5766453A (en) * 1980-10-14 1982-04-22 Ricoh Co Ltd Synthetic picture recorder
JPS57167057A (en) * 1981-04-07 1982-10-14 Seiko Epson Corp Optical printer
JPS6097370A (ja) * 1983-11-01 1985-05-31 Nec Corp 複写装置
JPS60103363A (ja) * 1983-11-10 1985-06-07 Konishiroku Photo Ind Co Ltd 複写装置
JPS60140221A (ja) * 1983-12-28 1985-07-25 Konishiroku Photo Ind Co Ltd 付加情報記録装置
EP0251617A2 (fr) * 1986-06-23 1988-01-07 Xerox Corporation Appareil de formation d'images à modes d'exploitation multiples

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 6, no. 145 (P-132)[1023] 4th August 1982; & JP - A - 57 66453 (RICOH) 22-04-1982 *
PATENT ABSTRACTS OF JAPAN, vol. 7, no. 10 (P-168)[1155], 14th january 1983; & JP - A - 57 167 057 (SUWA SEIKOSHA) 14-10-1982 *
PATENT ABSTRACTS OF JAPAN, vol. 9, no. 246 (P-393)[1969], 3rd October 1985; & JP - A - 60 97370 (NIPPON DENKI K.K.) 31-05-1985 *
PATENT ABSTRACTS OF JAPAN, vol. 9, no. 253 (P-395)[1976], 11th October 1985; & JP -A - 60 103 363 (KONISHIROKU SHASHIN KOGYO) 07-06-1985 *
PATENT ABSTRACTS OF JAPAN, vol. 9, no. 308 (P-410)[2031], 4th December 1985; & JP - A - 60 140 221 (KONISHIROKU SHASHIN KOGYO) 25-07-1985 *

Also Published As

Publication number Publication date
JPS63289544A (ja) 1988-11-28

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