FR2512220A1 - Electronic data inscription for aerial photography film - has character generator for adjusting all possible symmetry transformations of characters, interface and optical encoder - Google Patents

Abstract

The data are sequentially extracted from an electronic memory and written using at least one light display which shows at most one character. The displacement of the film is used to write side-by-side the various characters. A character generator is placed at the output of the memory. This generator performs, by electronic control, all the possible symmetry transformations of the characters. The generator is followed by an interface circuit which is connected to the input of the display. This system also has an optical coder which is driven by the film and which fixes the writing rate. The brightness of the display is electronically controlled by regulating the supply voltage to the display. The arrangement is partic. intended for aerial photography to record the longitude and latitude coordinates together with the bearing of the camera.

Description

SYSTEM FOR RECORDING DATA ON A PHOTOGRAPHIC FILM.

 The invention relates to a system for recording data on a photosensitive film placed in a camera, the data being extracted in sequence from an electronic memory and their recording being carried out using at least one recording device. luminous display displaying at most one character in which the displacement of the film is used to impress side by side the various characters on the film so as to form for each image parallel to the direction of displacement of the film at least one line.

 The system according to the invention can be used in particular in the case where the film moves either during the shooting or during the retraction thereof.

 Recording is possible up to film displacement speeds greater than 10m / s.

The object of the invention is to write on the film used in a camera (camera or photographic device) data contained in an electronic memory in the form of code
ASCII for example by translating them on the film in alphanumeric form and / or in the form of bar code. These data are, for example, spatial coordinates (longitude, latitude, course, etc.), time, date, these data being recorded by electrooptic means internal to the camera on the fringes of each view of the film.

 It is known, in particular from US Pat. No. 4,167,315, to insert alphanumeric data on the photographic film comprising perforations, the film being immobile during shooting. In this case, the line entered may extend in a transverse direction between two views of the film (which is a solution adopted by either PHüTOSONICS or, for example, for aerial cameras intended for maritime and terrestrial surveillance), or eA along the edge of the film perforations. The information is renewed for each view. The inscription of the entire line on the edge of a view is carried out at a given time. For this, a matrix of LED diodes forming for example an elementary display with 7 segments per character is placed in front of an exposure window, the elementary displays being arranged in line and their number being equal to the maximum number of characters to be written on the line (64 7-segment displays for 64 characters for example). The synchronization necessary for the boh functioning of this system is obtained from the perforations which extend on at least one edge of the film. This recording process reaches its limit when the number of data and therefore the number of characters to be written on each view clings. It then becomes difficult to increase the number of luminous displays on the film plane and the detection of a defective display which in some cases leads to erroneous recordings is difficult. To avoid these drawbacks, we know from German patent application 1 623 385 (second publication) a solution which consists in serializing the data which are presented in parallel form, for each image, and in recording them one after the other. and side by side on the film during its movement thanks to a single display device. The registration code used according to this German document is the binary numeric code. This simple code does not seem to pose any particular problem of synchronization between the speed of the film and the printing speed of the characters on the film, this problem not being not mentioned, and in return, the code thus recorded is difficult to decipher. For more complex codes, such as the alphanumeric representation or the bar code, on the other hand, poor synchronization can cause in the first case either an overlapping of the characters, or a very large spacing between them and in the second case variations width of the alternating black and white stripes which could distort the reading by computer.

 The object of the invention is to improve the recording of data on a photographic film with a view to easier subsequent analysis of this data.

 While retaining the advantages of the prior art, the disadvantages described above are avoided and the object of the invention is achieved, the registration system defined in the preamble being remarkable in that it comprises in cascade between said memory and said display device for registering said line a character generator designed to effect by appropriate electronic adjustment all the possible symmetry transformations of said characters and an interface circuit and that it furthermore comprises an optical encoder driven by said photographic film and fixing the data writing rate on the film.

 According to another characteristic of the invention, at least two lines are written on the film, including a line in the form of alphanumeric characters and a line in bar code.

 According to yet another characteristic of the invention, the brightness of said display device is adjustable.

 According to yet another characteristic, the system according to the invention comprises means for extracting the data from said memory in the opposite direction to the usual reading direction.

 According to yet another characteristic of the invention for the registration of at least one line in bar code, said character generator performs the conversion between the alphanumeric code and a second code interpretable as a bar code and said interface performs, among other things functions, a parallel-to-series conversion of said second code, said display device being reduced to a simple electroluminescent segment, the effect of the dO trail on the movement of the film being used to impress on the film white bands of separate determined width by black bands of determined width.

 The following description with reference to the accompanying drawings, all given by way of example, will make it clear how the invention can be implemented.

 FIG. 1 is the block diagram of a first embodiment of the invention for 1 inscription of alphanumeric characters.

 FIG. 2 represents the adjustment of the quantity of light received by the film by means of a screen disk with variable transparency.

 Figure 3 is the block diagram of a second model.

of embodiment of the invention, compatible with that of FIG. 1, for the registration of bar code.

 In FIG. 1 is represented at 1 an electronic memory: for example of the RAM type which receives via the bus 2 essentially alphanumeric information. This information is stacked in memory in a known manner by a writing signal, not shown, triggered for example before each shot. Memory 1 is part of an electrical assembly 3 which can be close to or distant from the camera shown schematically in 4 and comprising a data recorder 5 and a chamber 6. Two signals carried respectively by conductors 7 and 8 from the camera make it possible to extract the data from the memory. The signal on the conductor 7 is a read authorization signal triggered mechanically in an organ 9 between two predetermined moments of a shooting cycle of view, the film being mobile during the duration which separates these two moments. The signal on the conductor, from an optical encoder symbolized at 10, the movement of which is essentially in demodromic connection with the movement of the film, is formed of pulses such that a predetermined number of memory cells is read for each pulse . The data thus extracted from memory 1 are routed by bus 12 to a character generator 13, which transforms them into data suitable for display by bus 14. An interface circuit 15 makes it possible to attack the display 16 by means of a bus 17 under the desired conditions. In 18, a coded signal makes it possible to obtain the display of the characters according to the desired optical direction: either the character is displayed normally, or it is reversed in the up-down direction, or again in the right-left direction, or finally up-down and right-left.

 There are therefore, by means of two conductors 18, four possibilities of writing direction of the characters to be selected according to the desired optical mode.

 It will be noted in the case of inversion of t-ype right-left that the characters can be stacked in a known manner: enens inverse in memory 1. An equivalent means of proceeding consists in extracting the data from the stack, which can be done by means of an appropriate signal on a control conductor 19. A brightness adjustment of the display is possible by the interface circuit 15 and / or the power input 20 of the display 16, the amplitude of the power signal which can be adjusted by means of an adjustable source 21. On a conductor 22 a character ignition signal is transmitted to an organ 23 whose role is to calibrate this information before sending it in 24 attack the display 16.The function of the organ 23 is notably to adjust the exposure time of each character displayed at 16. In FIG. 11 the display consists of an alphanumeric display with 16 segments and two light points .

 An advantage of the invention is to present, thanks to the optical encoder 10, the characters displayed according to an invariable spacing and alignment, arranged in the format of the camera and regardless of the speed of the film.

 Several variants of the first embodiment are described below.

 According to a variant, it is possible, whatever the sensitivity of the film (from 8 to 3000 ASA), to adjust the amount of light received by the film by three means compatible with each other. The first means, described above, consists in an electronic adjustment at 21 of the supply voltage of the display, the second means in an also electronic adjustment, at 23, relating to the duration of the display time compatible with a negligible drag effect. The third means consists in interposing a screen disc 25 whose transparency is variable, as shown in FIG. 2, and which is actuated by a thumb wheel.

 According to another variant, provision can be made to write several lines in alphanumeric characters superimposed on the edge of cha) as seen. For two lines, for example, two single-character displays are superimposed or a two-character display is used and the information reaches the two characters alternately, this information being stored in stack in the memory in an interleaved manner. The two 18-segment displays can also be juxtaposed, which is the case with commercial displays. In the latter case, a small known optical device shifts the image of one of the displays to perform the additional line.

 The block diagram of FIG. 3 represents a second embodiment of the invention for writing data in bar code on the film. In this diagram, the same elements with identical or equivalent functions bear the same references as in FIG. 1. The bar code used is for example the code 39 known as "three among nine", offered by the company INTERMEC. It is possible to represent such a code by a configuration of 15 bits for example. Each obit, according to its level "0" or "1", causes on the film a black or white bar of elementary width, it being understood that writing of a character requires 9 alternating black and white bands, 6 of which have the elementary width, 3 a width twice the elementary width and the white band of spacing between two characters being chosen for example equal to three times the elementary width (6 +6 x 2) + 3 = 15). The character generator 13 contains the different possible 15-bit configurations. Given the up-down symmetry of the bar code, there is only one possible optical geometric inversion, the right-left inversion, controlled by the conductor 18, which must be accompanied by a reverse extraction of the data from memory 1 , controlled by the driver 19.

 The 15-bit configuration representative of each character appears in parallel on the output bus 14 to 15 conductors.

The interface 26 is a digital serialization device which translates the parallel bits into 14 into serial bits on the output conductor 27. The NAND gate circuit 28 authorizes the at the right time. passage of the bits towards its output 29, which makes it possible to switch on the display-diode 31. The authorization to display is given by the camera itself from the member 9, the signal obtained on conductors 7 and- 32 being shaped by a gate circuit 33 then supplied to a second input of the gate circuit 28. This same signal sends to memory 1 a read request (level 1) as in the case of the figure 1. For barcode registration, a sequencing circuit is required. This circuit is composed of the organs 10, 34 and 35 connected in cascade. The clock is given by the optical encoder 10, transmitted to a divider 34 (divider by 15 in this case) by the conductor 36, the signal divided by 15 is shaped by the circuit 35 thus making it possible to load the serializer register of the interface 26, which is incremented by the clock signal coming from the driver 36. The clock signals (driver 8) and of request reading (conductor 7) are necessary to control the reading of memory l.

 According to a variant of the second embodiment, it is possible, while keeping the diagram of FIG. 3, to represent the bar code in the form of a bit configuration comprising a number of bits lower than that indicated above. For the barcode says three of nine, for example; a configuration of 10 bits instead of 15 is sufficient, by means of taking a spacing between characters equal to twice the elementary width, this configuration of 10 bits being such that for example the bits of order impåir represent the black bands, the bits d 'even orders - the white bands, the bits of value O the thin bands (elementary width) and the bits of Value 1 the wide bands (double width of the elementary width) .This variant can be implemented with a slight complication the interface circuit 26 which must additionally include buffer registers, delay members for the serial transmission of each character and a divider by two of the clock pulses for checking the parity of said pulses. In this case, the divider 34 is a divider by 10 and the bus 14 has 10 conductors.

The system described above (second embodiment) installed in the camera therefore makes it possible to deposit on the film alphanumeric characters coded so that they can be read automatically by a method other than visual, by example by calculator. This reading can be done in two ways, either using a pencil, held in the hand, or using a fixed sensor in front of which the film moves. In these two cases, computer processing facilitates the insertion of comments and the possibility of bringing the various figures back to their actual dimensions. For example, information written on the edge of the film in the form
C 1792513 G 09355307 L.. etc ..., can be viewed as
CAP: 1790 25 '13 "
LONGITUDE: 930 55 '30 "7/10
LATITUDE: etc ....

With an adaptation of the diagrams of FIGS. 1 and 3 within the reach of a person skilled in the art, it is possible to combine the two embodiments described above, two associated lines superimposed giving for example the same information, one in alphanumeric writing, the other in barcode.

Claims (10)

CLAIMS: 1. System for recording data on a photosensitive film placed in a camera, the data being extracted in sequence from an electronic memory and their recording being carried out using at least one luminous display device displaying at most a character in which the displacement of the film is used to impress side by side the various characters on the film so as to form for each image parallel to the direction of displacement of the film at least one line, characterized in that it comprises in cascade between said memory and said display device for registering said line, a character generator designed to effect, by appropriate electronic adjustment, all the possible symmetry transformations of said characters and an interface circuit and which it further comprises an optical encoder driven by said photosensitive film and fixing the data writing rate on the film. 2. Data recording system according to claim 1 characterized in that at least two lines are written on the film, including a line in the form of alphanumeric characters and a line in bar code. 3. Data recording system according to the claim Characterized in that an electrical signal generated by a determined mechanical action during the image shooting cycle determines the phase of this cycle during which the data recording is done. 4. Data recording system according to one of claims 1 to 3, characterized in. that the brightness of the display device is obtained by an electronic adjustment of the supply voltage of said display device. 5. Data recording system according to one of the re vendications.l.à 4, characterized in that it further comprises between said display device and the film a disc-screen with variable transparency. 6. Data recording system according to one of claims 1 to 5, characterized in that it comprises means for extracting the data from said memory in the opposite direction to the usual reading direction. 7. Data recording system for recording at least one line in bar code according to one of claims 1 to 6, characterized in that for recording said line in bar code said character generator performs the conversion between the alphanumeric code and a second code interpretable as a bar code and that said interface effected, among other functions, a parallel-series conversion of said second code, said display device being reduced to a simple electroluminescent segment, the effect of drag to the movement of the film, being used to impress on the film white bands of determined width separated by black bands of determined width. 8. Data recording system for recording at least one line in alphanumeric characters according to one of claims 1 to 7, wherein said display device consists of an alphanumeric display with 16 segments and two points luminous. 9. data recording system according to claim 8, characterized in that it further comprises, between said memory and said alphanumeric display, means for electronic adjustment of the duration of the display time of each character. 10. Data recording system by means of which several lines are written on the film according to one of claims 1 to 9, characterized in that said lines are superimposed on the edge of the film, the characters written on the different lines being generated on the basis of a display device per line and the data being written in an interlaced manner in said electronic memory.