Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/0412—Digitisers structurally integrated in a display
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/00127—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/00127—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
  • H04N1/00129—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture with a display device, e.g. CRT or LCD monitor
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/0035—User-machine interface; Control console
  • H04N1/00352—Input means
  • H04N1/00392—Other manual input means, e.g. digitisers or writing tablets
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
  • H04N1/19—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using multi-element arrays
  • H04N1/195—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using multi-element arrays the array comprising a two-dimensional array or a combination of two-dimensional arrays
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/00127—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
  • H04N1/00204—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture with a digital computer or a digital computer system, e.g. an internet server

Definitions

• the invention relates to a display and writing device of the type making it possible, in particular, simultaneously or not, on the one hand to observe an image, and on the other hand, to write or draw or carry markers on a surface 'writing with an optical pencil; that is to say a device combining the functions of "image display” and "graphics tablet”.
• Such devices are known in which, on the one hand: - the image display function is provided by an image generator comprising a cathode ray tube; the image is formed in the cathode ray tube on a screen constituted by a front face or slab of the cathode ray tube, under the effect of a scanning of one or more electron beams; - on the other hand, the "graphic tablet” function is ensured using an optical pencil, and a writing surface which corresponds to the screen on which the image is formed, more precisely to a outer face and therefore opposite to that qtii is swept by the electron beam (s).
• An operator holding the optical pencil can designate with the aid of the latter, a point on the writing surface or a succession of points whose coordinates are memorized and can be reproduced by the image generator, possibly overprinted with a another picture.
• the optical pencil is sensitive to the light emitted by the screen or writing surface, and the location of a point on this writing surface designated by the optical pencil is obtained generally by locating the instant at which the optical pencil captures the light relative to the time during which a complete scanning of the screen or writing surface takes place.
• the present invention relates to an apparatus which combines the functions of image display and graphics tablet, without having the above-mentioned drawbacks.
• the device of the invention uses, on the one hand, a functioning writing surface. in a completely different manner from that described above, and uses on the other hand, an image generator of a different type from that mentioned above.
• the image generator capable of being used in the apparatus of the invention can be a display device of the type constituted for example by a panel of light-emitting diodes, arranged in line and in column according to a matrix arrangement, the functioning is in itself known; the matrix array of light emitting diodes is controlled, in a conventional manner, to produce the desired image.
• the display device may also be of the plasma type, that is to say operating in a conventional manner according to a matrix arrangement of electrodes.
• the display device can also be a display device of the liquid crystal type, which also uses in known manner an array of electrodes.
• these different display devices or image generators can fall into the same category which can be called a matrix type display device or a matrix type image generator; and all these different display devices or image generator; and all these different display devices or image generator; and all these different display devices or image generator; and all these different display devices or image generator; and all these different display devices or image generator; and all these different display devices or image generator; and all these different display devices or image generator; and
• a display and writing device comprising, an image generator, a pencil
• ⁇ optical, a writing surface is characterized in that it comprises a matrix of photosensitive elements, one photosensitive face of which constitutes the writing surface, and in that the optical pencil emits light radiation, the photosensitive matrix being placed in front of the image generator so that an image produced by the image generator is seen through the photosensitive matrix.
• FIG. 1 shows schematically and partially a display and writing device according to the invention, and illustrates how it provides at least the two functions "image display” and “graphics tablet”;
• 0 - Figure 2 schematically shows a second version of the device of the invention, particularly with regard to the position of a light source used to provide a third function "document reader”;
• FIG. 3 shows the electrical diagram of a -5 photosensitive matrix shown in Figures 1 and 2;
• - Figures 4a to 4c show explanatory signals for the operation of the photosensitive matrix shown in Figure 3, in the context of a "document reader”function;
• - Figures 5a to 51 show explanatory signals for the operation of the photosensitive matrix shown in Figure 3, in the context of the "graphics tablet”function;
• FIGS. 6a and 6b are side sections in two orthogonal directions, showing schematically by way of non-limiting example, an embodiment of the photosensitive matrix shown in Figure 3;
• FIG. 7 schematically illustrates, in a perspective view, a second embodiment of the photosensitive matrix.
• Figure 1 shows partially, schematically, a display and writing device 1 according to the invention.
• the display device 1 comprises a photosensitive matrix
• the photosensitive matrix 2 is represented by a substrate 3 carrying a plurality of photosensitive points PI, P2,. . . , Pn each comprising at least one photosensitive element, as is further explained in a continuation of the description relating to FIG. 3.
• the end of the photosensitive points PI to Pn is contained substantially in the same plane symbolized in FIG. 1 by a line in dotted lines marked 5, this plane representing a photosensitive surface 5 which extends in a plane perpendicular to that of the figure.
• the photosensitive surface 5 is divided into a plurality of n elementary surfaces Sel to Sen equal, each containing a photosensitive point PI to Pn.
• one side of an elementary surface Salt to Sen can have a length 11 of the order of 200 micrometers, while the height h of a photosensitive point PI to Pn, above the substrate 3, is of the order of only a few micrometers; the substrate 3 may itself have a thickness E of the order of 2 to 3 millimeters for example, especially if this substrate is made of glass in order to be transparent, as is necessary for the operation of the device.
• a surface image generator 7 of matrix type under the substrate 3, that is to say opposite to the photosensitive points PI to Pn, is arranged a surface image generator 7, of matrix type, the surface of which extends in a perpendicular plane to that of the figure.
• the image generator 7 can be constituted for example as it was previously mentioned, by a panel of light-emitting diodes (not shown) arranged in line and in column according to a matrix arrangement, the operation of which is known in itself: the matrix array of light emitting diodes is controlled, in a conventional manner, to light only some of the light emitting diodes and produce the desired image.
• the light (represented by arrows) which contains the image is emitted in the direction of the photosensitive matrix 2 which is partially crossed by this light, so that the image is visible through the photosensitive matrix 2.
• the photosensitive points PI to Pn have surface areas Sal to San of surface • sufficiently weak to allow the light emitted by the display device or image generator 7 to pass in sufficient quantity for the image projected under these conditions is visible through the photosensitive surface 5 under correct conditions (the active surfaces Sal to San are situated in a plane perpendicular to that of the figure and symbolized on the latter by the length 12 on their side, these active surfaces corresponding in a way to the section of the photosensitive elements that comprise the photosensitive points PI to Pn). Tests have shown that the image which is thus projected through the photosensitive surface 5, is visible under correct conditions when the active surface
• Sal to San photosensitive points PI to Pn is equal to or less than substantially 50% of an elementary area Salt to Sen.
• the photosensitive surface 5 constitutes the photosensitive face of the photosensitive matrix 2, and so that the photosensitive points PI to Pn are not illuminated by the light coming from the image generator 7, an opaque screen 12 is disposed between the substrate 3 and each photosensitive points PI to Pn.
• the display device 1 further comprises an optical pencil 15. According to a characteristic of the invention, the optical pencil 15 emits light radiation in the form of a light brush 16, light to which the points are sensitive. photosensitive PI to Pn on the side of the photosensitive surface 5; so that the photosensitive surface 5 represents a writing surface 5.
• the optical pencil 15 being a light emitter, it is possible for an operator (not shown) holding the optical pencil 15 by hand, to illuminate the photosensitive surface 5 or writing surface using an optical pencil , and thus to designate a given zone (formed of one or more elementary surfaces Salt to Sen contiguous) at a given time.
• the operator can thus successively designate different zones on the writing surface 5, to constitute, for example, fixed references distant from each other; the operator can also illuminate the photosensitive surface or writing surface 5 so as to describe thereon any curve of pace.
• the illumination of an elementary surface Sel to Sen is detected by the photosensitive point PI to Pn contained in this elementary surface, and which delivers a signal which allows to locate it; the location of a succession of adjacent photosensitive points PI to Pn makes it possible to reconstruct a curve drawn on the photosensitive surface 5 or writing surface using the optical pencil 15.
• the image generator 7 can be constituted by a display device of a different type, for example a display device of the plasma type, in itself conventional.
• a display device of the conventional liquid crystal type which is represented by a rectangle in dotted lines 20.
• the image generator or display device 7 can be replaced by a light source, that is to say constitute a light device 7.
• a display device of the plasma type or of the type comprising a matrix of light-emitting diodes constitutes a light device, which can provide either a light source function or an image display function.
• a light device 7 formed by light-emitting diodes for example, all the light-emitting diodes are actuated and supply light; for operation as an image display, the matrix array of light-emitting diodes is controlled to produce the desired image (of course the use of the optical pencil 15 is possible during the viewing of the image); and for operation as a graphics tablet only, all the light-emitting diodes are off and the light device 7 produces no light, thus allowing the free use of the optical pencil 15.
• the light device 7 consisting of a display device of the plasma type, for example, or of the light-emitting diode panel type, performs the function of displaying images, while allowing operation as a graphic tablet, and also allows using the photosensitive matrix 2, to obtain a third function with the viewing and writing device 1, which consists in reading a document 10.
• the light device 7 constitutes a source of light: the light emitted by. this light source illuminates a face 11 to be analyzed of the document 10, which is pressed against the photosensitive surface or writing surface 5.
• the document 10 is pressed against a transparent screen 9 made of glass or plastic for example, which mainly fulfills a mechanical protection function with respect to the photosensitive surface or writing surface 5.
• the light coming from the light device 7 is reflected by the face 11 to be analyzed , and illuminates the photosensitive points PI to Pn of the matrix 2.
• the light device 7 can in this case constitute only a light source, the liquid crystal display device 20 being disposed between the light device 7 and the photosensitive matrix 2.
• the light device 7 can be designed in a much simpler manner, and contain for example fluorescent tubes (not shown), and include a surface 8 constituted by a perfectly diffusing partition, in itself conventional, so as to emit a flow of light in a relatively homogeneous manner over the entire surface 8.
• the liquid crystal display device 20 usually comprises two partitions or substrates 21, 22 carrying electrodes (not shown); between these substrates 21, 22 is arranged a volume 23 filled with the liquid crystal.
• the substrate 3 belonging to the photosensitive matrix 2 can also constitute the partition or substrate 21 of the liquid crystal display device 20.
• FIG. 2 shows another version of the invention in which the document to be analyzed, identified 10a, is of a transparent or semi-transparent type, such as for example a graphic radio film.
• the document 10a is placed on the protective screen 9, that is to say above the photosensitive surface or writing surface 5.
• the reading of the document 10a is obtained using a light source 25, of surface type which is placed above the document 10a, the latter being thus disposed between the photosensitive surface 5 and this
• the light device 7 is not mandatory to have the light device 7, as a light source, except of course if the display device or image generator is constituted by the liquid crystal display device 20 .
• the second light source 25 can be moved away from the analyzed document 10a, so as to allow access to the optical pencil 15 (not shown in FIG. 2). It should be noted that in the latter case, in particular if the document 10a is an X-ray film, the
• __ optical pencil 15 can be used, for example, to carry markers superimposed on the image itself, and for this purpose the light device 7 as a light source, can be useful for illuminating the image carried by document 10a, while having a minimal influence on the photosensitive points PI to Pn.
• Figure 3 shows partially the electrical diagram of the photosensitive device 1 according to the invention, and particularly illustrates, by way of nonlimiting example, the photosensitive matrix 2 and the manner in which the photosensitive pixels are formed with it; the structure presented
• the matrix comprises a plurality of photosensitive points PI, P2,. . . , P9 which are arranged in rows and columns and which each consist of a first and a second element respectively Da, Db connected in series with each other, and at least one of which is a photosensitive element.
• the first and second elements Da, Db each consist of a diode, the two diodes Da, Db being connected in series with each other and mounted at the head spade, that is to say with opposite directions of conduction with respect to each other; such an assembly of photosensitive dots being described in a French patent application No. 8G 14058 filed on October 9, 1986 in the name of THOMSON-CSF.
• This patent application relates to a photosensitive device in the solid state, having a photosensitive matrix, the photosensitive dots of which are constituted in the same manner as mentioned above and this patent application describes. in detail the operation of such photosensitive dots, and further describes a reading method and a method of manufacturing a matrix comprising such photosensitive dots; also, this French patent application n ° 86 14058 must be considered as being part of the present description.
• the number of photosensitive points PI to P9 is limited to 9 according to a 3 ⁇ 3 matrix assembly to simplify FIG. 3, but in the spirit of the invention this matrix assembly can have a much greater capacity. larger, by several million points for example.
• the matrix 2 comprises in-line conductors LI to L3 and in column conductors FI to F3, the number of each type of these conductors being limited to 3, taking into account the example of FIG. 3 where only 9 photosensitive points PI to P9 are represented.
• the photosensitive points PI to P9 are each formed at the intersection of a line conductor LI to L3 and a column conductor FI to F3 .
• Each photosensitive point PI to P9 has a first end 10 connected to a row conductor LI to L3, and has a second end 11 connected to a column conductor FI to F3.
• the meeting point between the first diode Da and the second diode Db constitutes an area A where charges generated by at least one of the two diodes Da, Db can be stored; the amount of charge being proportional to the illumination of the photosensitive point, • that is to say to the illumination of photosensitive elements or that comprises the photosensitive point.
• the two diodes Da, Db can be photosensitive elements, but according to a characteristic of the invention, it is sufficient that only one of these two diodes Da, Db is photosensitive to allow the two operating modes provided for the photosensitive matrix 2, namely: operation in "graphics tablet” mode and operation in "document reader” mode.
• the diode Da or Db which is necessarily photosensitive is the one which, during illumination of the photosensitive points PI to P9, is the only one which is reverse biased in the tablet function graphic.
• the first and second diodes Da, Db are photodiodes, and they are mounted so that their anodes respectively 10 and 11 are connected respectively to a line LI to L3 and a column FI to F3.
• the photodiodes or diodes Da, Db could be mounted in opposite directions of conduction to those shown in FIG. 3.
• diode is meant not only a semiconductor diode, but also possibly a transistor or phototransistor of a NIPIN or PINIP type for example, as soon as the base of this transistor is floating, that is to say not connected.
• the function provided by the first diode Da is that of a switch or switch which, when the first diode Da is forward biased, is "on” (that is to say that it has a low resistance), and which, when the first diode Da is reverse biased is "open” (that is to say that it has a very high resistance).
• the operation of the matrix 2, within the framework of the "document reading” function, corresponds to the operation described in the French patent application No. 86 14058 previously mentioned, and requires in particular that, for each photosensitive point PI to P9, during the illumination of the latter by the light coming from document 10, 10a to be read, the two diodes Da, Db are reverse biased; this being obtained by bringing the column conductors FI to F3 to a given potential or reference voltage VR, and on the other hand, by applying successively to each of the line conductors LI to L3 a voltage pulse with respect to the reference voltage column VR ; this pulse is a positive pulse, taking into account the direction of mounting of the diodes Da, Db in the nonlimiting example shown in FIG. 3.
• Each column conductor FI to F3 is connected to the negative input "-" of an amplifier GF1 to GF3 mounted as an integrator; an integration capacitor CF1 to CF3 being mounted between the negative input "-" of the amplifier GF1 to GF3, and the output OF1 to OF3 of this amplifier.
• the second positive input "+" of each amplifier GF1 to GF3 is connected to the reference potential VR previously mentioned which may be ground for example as shown in FIG. 3.
• Each integrating amplifier GF1 to GF3 further includes a switch IF1 to IF3 called reset switch, mounted in parallel with the integration capacitor CFl to CF3; the reset switches IF1 to IF3 consist of MOS transistors controlled by reset signals V. RESET. The reset switch IF1 to IF3 of a given integrating amplifier GF1 to GF3 is maintained
• the outputs OF1 to OF3 of the amplifiers GF1 to GF3 are connected to an analog data acquisition register 32 called column acquisition register, constituted for example by a shift register with parallel input EF1 to EF3 and serial output SF1, of the CCD type ( Charge Coupled Device) for example.
• the connection diagram of the column conductors FI to F3 which has just been described is a conventional diagram, which constitutes a reading device and which makes it possible to acquire the charges which - circulate on these conductors
• the line conductors LI to L3 must be connected not only to an addressing device (comprising in particular a line register 46 and a pulse generator 42) making it possible to apply a
• Each of the line conductors LI to L3 is connected to the negative input "-" of an integrating amplifier GL1 to GL3, of the same type as the integrating amplifiers connected to the
• each line conductor LI to L3 corresponds to the potential of the second input or positive input "+" of the amplifier GL1 to GL3.
• an integration capacitor CL1 to CL3 is mounted between the negative input "-" and
• the OL1 to OL3 output of this amplifier In parallel on each of the integration capacitors CL1 to CL3 is mounted a reset switch IL1 to IL3; these switches being constituted for example by MOS transistors controlled by second reset signals V2. RESET. These second reset signals V2. RESET are intended to short-circuit the integration capacitors CLl to CL3 and CFl to CF3 during a given phase of operation in "graphics tablet” mode, and they are also applied to the integration capacitors mounted on the amplifiers GF1 to GF3 of the column conductors FI to F3; to this end, the switches IF1 to IF3 mounted on the amplifiers GF1 to GF3 are controlled by the first reset signals V. RESET, or by the second reset signals V2.
• the outputs OL1 to OL3 of the amplifiers GL1 to GL3 are connected to inputs ELI to EL3 of a second acquisition register 33 called the line acquisition register, constituted for example by a shift register of the type with parallel input and serial SOL output.
• the column and line acquisition registers 32, 33 respectively comprise a control input 34, 35 to which loading control signals SCI, SC2 are applied respectively, when it is desired to load into these registers 32 , 33 the signals which are applied to their inputs EF1 to EF3 and ELI to EL3.
• the information contained in the acquisition registers 32, 33 is transferred to main memories (not shown), in themselves conventional, and this information is then processed in a conventional manner so as to reconstruct an image formed on the sensitive surface 5 of matrix 2, either in document reader mode (only for column 32 acquisition register in this case), or in graphics tablet mode.
• the output of the signals contained in the acquisition registers 32, 33 is operated under the control of pulses or transfer signals ST applied to a transfer control input 38, 39 that comprise respectively the column 32 acquisition register and the row 33 acquisition register; these transfer pulses ST being delivered by the same transfer pulse generator 40, so as to determine a known phase relationship in the output of the signals from the two acquisition registers 32, 33, with a view to designating between which line conductor LI to L3 and which column conductor FI to F3 was connected a photosensitive point PI to P9 lit at a given time by the optical pencil 15 (shown in Figure 1).
• each positive input "+" of the amplifiers GL1 to G13 is connected on the one hand to the line pulse generator 42 via a line pulse interrupter IL1 to IL3, and connected on the other hand to the DC voltage source 45 via another switch IV1 to IV3; at the level of an amplifier GL1 to GL3, only one or the other of these switches being made "on" at the same instant.
• the switches IL1 to IL3 are constituted by MOS transistors, and are controlled respectively by an output Ul, U2, U3 of a line shift register 46, so as to successively connect the line conductors LI, L2, L3 to the generator. line pulses 42, this succession taking place under the control of line shift signals SDL which are applied to an offset control input 47 of the shift register 46.
• the other switches IV1 to IV3 also connected to the positive inputs "+" of the amplifiers GL1 to GL3 are also MOS transistors, and are controlled simultaneously by a DC voltage signal VSG which is established at the same time as the "graphics tablet” function is established.
• a voltage pulse SL delivered by the line pulse generator 42 is applied to the positive input of the amplifier GL1, and this pulse positive is found on the negative "-" input of this amplifier, that is to say on the line conductor LI, so that the pulse SL is applied to all the photosensitive points PI to P3 connected to this line conductor.
• the result of the application of this line pulse SL is an injection of charges on each of the column conductors FI to F3, these charges each corresponding to the charges stored in zones A of photosensitive points PI to P3.
• the signals constituted by these charges are present at the output of the amplifiers GFl to GF3 in the form of voltage, and these signals are injected into the column acquisition register 32.
• the integration capacitors CFl to CF3 mounted on the amplifiers GFl to GF3 are then short-circuited, and the line pulse generator 42 is connected to a line conductor along L2 to which is also applied a line pulse SL which leads to injecting on each of the column conductors FI to
• the column acquisition register 32 having been emptied beforehand and the charges it contained transferred to a main memory as previously mentioned, the column acquisition register 32 can be loaded again by the charges contained in point A of the photosensitive points P4, P5, P6, as in the previous example; and the same cycle is reconstituted for the third conductor line L3 and so on until all the photosensitive points of all the lines of the matrix; the signals corresponding to the entire image of the document to be read being delivered at the output SF1 of the column acquisition register 32, they can be stored in a main memory.
• each photosensitive point PI to P9 remains reverse biased and, if it is lit, it generates charges which circulate on the row conductor and on the column conductor between which the photosensitive point PI to P9 is connected located in the elementary surface Salt to Sen lit by the optical pencil 15.
• the optical pencil illuminates the elementary surface Se6, that is to say the photosensitive point P6, the zone A of the latter is at a positive potential close to that delivered by the DC voltage source 45. Consequently , the second photosensitive diode Db is reverse biased and delivers charges and a current represented by an arrow 50 flows on the line L2 and the column F3 crossing the photosensitive point P6, that is to say passing through the diodes Da, Db of the latter.
• the data or signals contained in the acquisition registers 32, 33 can be transferred to main memories : this is accomplished by simultaneously applying to the two acquisition registers 32, 33 the same 5 ST transfer control pulses delivered by the transfer signal generator 40.
• These ST transfer signals are delivered at a frequency for example of 1 MHz : under these conditions, assuming that the matrix 2 is a matrix of for example 4 million photosensitive points formed using 0 using 2,000 row conductors and 2,000 column conductors, the simultaneous transfer of the 2,000 data stored in the register line 33 and 2000 data stored in the column 32 acquisition register, is performed in a time of 2 milliseconds.
• an elementary surface Sel to 5 Se9 have the same length 11 of the order of 100 micrometers for example, and if on the other hand the speed of movement of a light brush on the photosensitive surface 5 is of l '' order of 3 to 4 cm per second, the time which elapses between the start of the illumination of an element surface Sel at Se9 and the moment when this elementary surface has been fully illuminated is much greater than the time of transfer of the above-mentioned data, so that the acquisition of the data relating to a complete image of the photosensitive surface 5 can be carried out for the time necessary to pass through an elementary surface 5.
• the active surfaces Sal to Sa9 of the photosensitive points PI to P9 are much smaller than the elementary surfaces Sel to Se9.
• the active surface Sal to Sa9 of a photosensitive point pi to p9 corresponding to the section of the photosensitive element which the latter comprises, that is to say generally to the crossing surface between the line conductors L1 to L3 and the column conductors F1 to F3 and which is given by the width of these conductors.
• FIGS. 4a to 4c illustrate the operation of the photosensitive matrix 2 in the document reader mode which has been explained with reference to FIG. 3.
• FIG. 4a shows the application to the first line conductor L1 of a line pulse SL, delivered by the line pulse generator 42, so as to particularly illustrate the operation of the second photosensitive point P2;
• - Figure 4b shows the potential variations
• FIG. 4c illustrates the correlation in time between the charges Q delivered by the photosensitive point P2 and the application of the line pulses SL. It should be noted that, in FIG. 4c, only the charges generated by illumination are represented, and the charges which can circulate on the column conductors F1 to F3 are not represented consequently only voltage variations applied to photosensitive points.
• FIG. 4a at a time t0, a line pulse SL begins which reaches an amplitude VO, this amplitude VO is kept until an instant t3.
• FIG. 4b shows that with the start of the pulse SL, the voltage Va in the zone A increases, from the instant tO, to reach a value substantially equal to the value VO at an instant t2 which precedes the instant t3 .
• FIG. 4c shows that a quantity of charge Q circulates on lO ' i column F2, charge which is generated by the second photosensitive point P2 at an instant tl comprised between instant tO and instant t2; this instant tl corresponding to the moment when the first diode Da goes into direct polarization.
• the pulse SL applied to the line conductor L1 FIG. 4a
• Db are reverse biased and behave like capacitors; it is noted that the voltage Va at point A (FIG. 4b) has passed to a value VI substantially equal to half of VO, which confirms that the two diodes Da and Db are polarized at
• FIGS. 5a to 51 illustrate the operation of the photosensitive matrix 2 in the case of operation as a graphics tablet.
• FIG. 5a illustrates a slot which begins at time tO.
• FIGS. 5b and 5f show respectively that at time t0 the circulation of a current I begins on the first row conductor L1 and on the second column conductor F2;
• FIGS. 5c, 5d, 5e, 5g show that no current flows on the other row conductors and column conductors when only the second photosensitive point P2 is lit.
• Figure 5h illustrates a variation in output voltage V. OLl generated at the output of the first line amplifier GLl by the integration of the current IL1; and
• FIG. 5i shows a variation in output voltage V. OF2 generated at the output of the second column amplifier GF2 by the column current IF2.
• FIG. 5j shows that at an instant t2 the loading control signal SC is applied to the acquisition registers 32, 33, in order to load therein the signals which correspond to the output voltages of the amplifiers GL1 to GL3 and GFl to GF3. Since only the second photosensitive point P2 is lit, only the output voltages V are modified.
• OLl and V. OF2 Figures 5h and 5i) which correspond respectively to the first row amplifier GL1 and to the second column amplifier GF2; the signals thus loaded being the voltage levels VS1, VS2 which, at time t2, comprise the output voltages V. OLl and V. OF2 ( Figures 5h and 5i).
• FIG. 5k illustrates the application of the second reset signal V2. RESET, at an instant t3 following the end of the loading command signal SC; the second signal from reset- to zero V2.
• RESET is used to short-circuit all the integration capacitors CLl to CL3 and CFl to CF3, so as to prepare all the line and column integrating amplifiers GLl to GL3 and GFl to GF3 to integrate a possible current on a line or a column, in a subsequent cycle.
• the following cycle begins at an instant t4, corresponding to the end of the signal V2.RAZ, from which the operations described above are repeated.
• the integrating amplifiers GL1 to GL3, each connected to an online conductor L1! to ; Eî, and the column amplifiers GFl to GF3 each connected to a column conductor Fl to F3, fulfill a function of current detector.
• the operating cycle which has just been explained has therefore already taken place, that is to say that the data have already been transferred to the registers 32, 33.
• the data or signals contained in the acquisition registers 32, 33 are transferred to the main memories during a transfer time T2 comprised between the end of a loading command signal SC and the start of the next load control signal SC, as shown in FIG. 5j.
• This transfer of the data contained in the acquisition registers 32, 33 is effected by applying, during the transfer times T2, the transfer pulses ST (shown in FIG. 51) simultaneously to the two acquisition registers 32, 33.
• Figures 6a and 6b are side sections in two orthogonal directions, which show, by way of nonlimiting example and schematically, a first embodiment of a photosensitive matrix 2 according to the invention.
• the photosensitive matrix 2 is formed on a transparent substrate 3, for example made of glass or else made of quartz.
• This conductive layer 61 is etched so as to constitute the column conductors F1 to F3. It should be noted that the column conductors being opaque, they can constitute the screens 12 shown in FIG. 1, and which are arranged between the substrate and the photosensitive points PI to Pn.
• the conductive layer 61 is covered, after etching, by a stack 60 of several semiconductor layers 62, 63, 64, 65, 66 intended to constitute the first and second diodes Da and Db arranged one above the other; these two diodes Da, Db being in the nonlimiting example both described as photodiodes: there is first above the conductive layer 61, a layer 62 of hydrogenated amorphous silicon, doped with a P-type impurity; then above the layer 62 of P doped silicon there is a layer 63 of intrinsic hydrogenated amorphous silicon; then above the layer 63 of intrinsic amorphous silicon, there is a layer of hydrogenated amorphous silicon 64 doped with an N-type impurity, phosphorus for example.
• the semiconductor layers are thus deposited from which the second diodes Db are made; the third semiconductor layer 64 formed of hydrogenated amorphous silicon doped with an N-type impurity being common also to the first diodes Da.
• the third semiconductor layer 64 of N-doped silicon there is a layer 65 of intrinsic hydrogenated amorphous silicon, then finally a layer 66 of hydrogenated amorphous silicon doped with a P-type impurity, for example boron, is deposited. .
• the five semiconductor layers 62, 63, 64, 65, 66 are then etched in an island pattern.
• a layer 67 of an electrically insulating and transparent material for example made of silicon nitride, is deposited.
• openings are made in this last insulating layer 67, above the first diodes Da, so as to bring the latter into contact with a layer 70 of material electrically conductive and transparent, made of indium tin oxide (ITO) for example, this conductive layer 70 being etched to constitute the conductors in line L1 to L3.
• ITO indium tin oxide
• the substrate 3 of the photosensitive matrix 2 it is also possible to use the substrate 3 of the photosensitive matrix 2 to produce one of the partitions, the first partition 21 for example, of the liquid crystal display device 20 shown in FIG. 1. It Sufficient for this purpose to deposit an electrically conductive layer 73 and transparent, made of indium tin oxide (ITO) for example, on a face 72 of the substrate 3 which is opposite to the diodes Da, Db; this transparent conductive layer constituting for example the solid surface electrode that conventionally comprises a liquid crystal display device.
• ITO indium tin oxide
• Figure 7 is a perspective view which schematically and partially shows the photosensitive matrix 2 in another embodiment.
• This new embodiment has the advantage, compared to the embodiment shown in FIGS. 6a, 6b, of requiring less masking and engraving operations.
• the electrically conductive layer 61 has been deposited on the substrate 3 and then etched so as to constitute the column conductors F1, F2.
• the 5 semiconductor layers 61 to 65 which form a stack 60 intended to constitute the superimposed diodes Da and Db.
• the layer is deposited directly electrically.
• upper conductor 70 transparent, intended to be etched to form the line conductors L1 to L3.
• the upper electrically conductive layer 70 and the stack 60 of semiconductor layers are then simultaneously etched, so that the stack 60, after etching, forms strips 60a located under the line conductors L1, L2 and consequently having the same shape and the same surface as these conductors L1, L2.
• the photosensitive points PI, P2, P4, P5 which are thus produced are located at the intersection of the line conductors L1, L2 and the column conductors Fl, F2.
• the active surface Sal, Sa2, Sa4, Sa5 (represented by a hatched surface in FIG. 7) of the photosensitive points PI, P2, P4, P5, consists solely of the intersection surface of the line conductors and the column conductors Ll, L2, Fl, F2.
• the superimposed diodes Da and Db are formed only between the "crossing points of the row and column conductors, in particular because it is only in the volume located under the active surfaces Sal, Sa2 , Sa4, Sa5 that a sufficient electric field has been established. Consequently, the resistance presented by zones Z situated between two adjacent photosensitive points and located under the same line conductor (the photosensitive points PI and P2 for example), is large and these photosensitive points are not short-circuited, of course this technique is made possible by the fact that the active surfaces Sal to Sa9 have a surface "considerably less" than the surface of an elementary surface Salt to Se9.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Human Computer Interaction (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Control Of Indicators Other Than Cathode Ray Tubes (AREA)
• Facsimile Heads (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9365182

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (2)

• 1988
  • 1988-04-11 FR FR8804769A patent/FR2629939B1/fr not_active Expired - Lifetime
• 1989
  • 1989-03-21 EP EP19890904083 patent/EP0378593A1/de not_active Withdrawn
  • 1989-03-21 WO PCT/FR1989/000129 patent/WO1989009960A1/fr not_active Application Discontinuation
  • 1989-03-21 JP JP50375189A patent/JPH02504192A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events