SE450803B - DEVICE FOR DEVICES FOR CONVERTING A PREVIOUS PICTURE PRESENTATION TO AN ELECTRIC SIGNAL AND VICE VERSA - Google Patents

Description

45n.so3 electrical signal produced from an image substrate in an apparatus which may be referred to as an image transmitter.

It also happens that you create an image signal to obtain a non-permanent image presentation on a monitor. Such an image presentation can be used for remote transmission or even locally for information, control or editing. Such an image presentation can, as is well known, be obtained with the aid of a TV camera which gives a signal to a monitor. For such a signal, however, the capacity of simple telephone lines is not sufficient and in many cases it is preferred to form and transmit the signal as a low frequency signal, which is recorded in a memory and then given the form of a high frequency signal which is applied. a monitor. To generate the transmitted signal, an image transmitter adapted for the purpose is required.

In color separation, it is common to use different color filters in front of the scanning device moving over the image. The color filters must then have the same size as the image area selected for scanning. This means relatively bulky color filters, which must be manufactured with high precision, which is why the cost is significant. In addition, any irregularity in the color filter surface will result in a signal which does not give a correct image representation at the places where the color filter is not correct.

The object of the present invention is to provide a compact device for color separation in signal formation and reproduction, which entails a lower cost for the color filters than in previously used systems and which largely eliminates the risk of incorrect signals due to faults in the color filters.

The invention also has for its object to provide a device for color separation, which enables the formation of a color image signal in an automatic process which can be controlled in different ways depending on the purpose of use.

The object of the invention is achieved by carrying out the device with the features stated in claim 1.

An accompanying embodiment of the invention is shown in the accompanying drawings. The exemplary embodiment relates to an image transmitter which can be used for remote transmission of images or for generating an image signal for other purposes such as for cliché production.

Fig. 1 schematically shows the image transmitter; Fig. 2 shows on a larger scale and in a first embodiment a scanning device used in the image transmitter. and which is embodied according to the invention; and Fig. 3 shows a second embodiment of the scanning device.

According to Fig. 1, an image transmitter on and in a housing 1 comprises a lighting device 2, an image holder 3, which is embodied according to the invention, a mirror 5, a lens 6, a scanning device 7 with an image window 8 and a row scanner 9 and a motor 10, a frame beam 11, on which the mirror 5 and the lens 6 and the scanning device 7 are attached together with a pivotable mirror 12. The outside of the housing, in addition to the lighting device 2, a projection window 14, a keyboard 15, an electronics unit 16 and an electronic display 17 .

The lighting device 2 is foldable and below it there is a circular opening 18 in which a circular socket 20 on the image holder 3, see Fig. 2, can be slid down. The film holder 3 further has a picture window 21, which, when the film holder with its socket is located in the opening 18, is placed in the beam thread from the lighting device 2, when it is in the lowered position down to the mirror 5 for deflection by the same through the lens 6 up to the scanning device 7. however, as shown in Fig. 1, the beam path can be deflected to the projection window 14 by folding up the mirror 12.

When using the image transmitter, an image inserted in the image holder 3 shall be projected through a light flux from the illumination device 2 via the mirror 5 and the lens 6 in the image window 8 of the scanning device 7, where it is scanned the number of times determined by the color separation by line scanner 9. formation of an electrical signal. This signal can be sent to a receiver or otherwise used for image reproduction purposes.

The scanning device 7 shown in Fig. 1 is shown on a larger scale and in more detail in Fig. 2. The figure then shows a first, simpler embodiment. Said row scanner 9 consists of an elongate body which is movable along guides 20 by means of said motor 10. The motor 10 as well as the guides 20 are suspended in a frame 21 with an opening 22 in which the row scanner 9 can move and which in mainly represents the image area. The image to be scanned consists of a projection within the aperture 22 of the actual film image 4 in the image holder 3. The projection takes place under illumination from the illumination device 2 along a beam path via the mirror 5 and through the lens 6, as previously stated. The image is thus projected with the focal plane located in the aperture 22 and placed at the level of a row scanning element 23 on the row scanner 9. This row scanning element consists of a row of light-sensitive elements, which by electronic control can be caused to emit electrical signals successively along the row of elements. line of the image is scanned. As the line scanner moves on the guides 20, line by line of the image is scanned until it is completely scanned. This results in a modulated electrical signal, which represents all the pixels of the image, the resolution of which is determined by the size and division of the light-sensitive elements along the line scanner 9 and its speed of movement in relation to the scanning rate along the line scanner, thus the line density.

The light-sensitive elements give a signal, the amplitude of which depends only on the light input to the element without any indication of the color. For technical reasons, the sensitivity to light intensity may be different for different colors and different in relation to the human eye's perception of the luminosity of different colors, but this is not something that can be used to create a signal that also indicates the color.

Instead, as initially stated, the image must be separated into different colors by means of a color filter and, in turn, the same color must be scanned for color. As a minimum, three colors are required; one can produce all colors and color shades by a mixture of three colors if these are placed at equal distances within the technical color tone circle. Separation in more than three colors also occurs. At color printing, it is common to apply a separate print in black, which corresponds to a black and white signal. Such a print is called a four-color print. * h I) 450 805 For color separation, color filters are used, in order not to distort the color perception when viewing the image in the image window 14 via the mirror 12, it is preferred to place the color filter next to the scanning device 7. According to the invention, the color filters each consist of a narrow disc 2É. which according to Fig. 2 is inserted into holding strips 26 on the line scanner 9.

The color filter discs 25 will therefore, when in turn attached to the line scanner, follow the same during the scan. Each color filter disc need only have the same width as the light-sensitive elements in the plane 23, thus in principle only one line width. For handling reasons, however, it is appropriate for the disc to have a slightly larger width, which facilitates the handling and the precision of the insertion need not be so great. The length must of course be equal to the length of the row of photosensitive elements.

The required color filters can be combined in a switching device, so that the filters do not have to be handled separately as in the retaining strips 26 shown. One possibility is to make a color filter disc with several areas each with one of the determined colors. By sliding the disc in different positions in the strips 26, the different areas can be placed in front of the row of light-sensitive elements. The shifting device can alternatively be designed as, for example, a turret device.

The form of the invention shown in Fig. 2 represents its simplest embodiment with removal and insertion of the color filters in turn by hand. The further mentioned form with a switching device, which can be automatic, represents a more developed embodiment. A further developed form is shown in Fig. 3 and will be described below.

According to Fig. 3, the scanning device 7 (the same designations as in Figs. 1 and 2 used in Fig. 3 for common parts) has the line scanner 9, which is movable along its guides 20. However, there is a second guide device 30 in front of the line scanner 9, thus on the side from which the beam from the projection device falls. The guide device 30 supports by means of a slide 31 a plate 32, which is parallel to the sound-sensitive elements of the line scanner 9. The plate 32 carries a number of color filters 34 inserted therein through openings 33. Seven color filters 450 803 are shown here. To obtain the desired color separation, as mentioned, there is a minimum of three. In this case, the device has been made more universal in that three filters are provided for separating positive images and three for negative images and an aperture 33 is reserved for forming a black and white signal. This is intended for black and white images and for the black print of the four-color print.

The device further comprises a drive device for the slide 31, so that it can be moved back and forth along the guide device 30. The latter suitably comprises a screw, 35, which engages with a nut thread (not shown) on the slide 31 and which is driven by a second motor 36, which included in the drive device.

The drive devices for moving the line scanner 9 along the guides 20 and the color separation slide 31 with the filters 34 along the guide device 30 are arranged for a specific, coordinated drive process. This is achieved by the rotational control of the motors 10 and 36. As is well known, there are today electric motors, often of the stepper motors type, which can be driven in complicated rotational patterns, usually under the control of a computer equipment. Such a device was present in the present scanning device and must at least in the embodiment now described be arranged for coordinated control of the two vaginal devices.

How this can be done is included in the area of expertise of the person skilled in the art and does not need to be described in more detail here.

However, the governance process must be described here.

This can be of two alternative forms. In one form, the image is scanned in its entirety in the number of complete processes, which corresponds to the number of colors in which the image is to be separated.

In this case, the control process is such that the disc 32 accompanies the line scanner 9 when it moves over the image surface and with a specific color filter 34 placed throughout the entire process in front of the light-sensitive elements of the accompanying line scanner. In the next movement over the image surface of the line scanner 9 to register the next color, the disc 32 is moved in the same way together with the line scanner but now offset, so that the next color filter 34 in turn will follow the line scanner placed in the middle of its light-sensitive elements. The resulting signal sequence is thus divided into a number of sub-signals, each 7 450 805 representing a complete representation of the whole image and in turn corresponding to the different separation colors.

In the second type of control sequence, the line scanner 9 first scans a single line or alternatively a smaller group of lines across the image surface to represent a color whose corresponding color filter 34 is then located in the middle of the line scanner. Thereafter, the color separation disc is moved so that the next color filter 34 comes in the middle of the line scanner 9 and it now scans the same line or possibly the same group of lines as was previously scanned at the first color. In this way, the same image section is preferably scanned in turn, preferably a single line, as many times as the number of colors in which the image is to be separated by successive movement of the color filters relative to the line scanner.

When all colors are represented, the line scanner is moved to scan the next line according to the same pattern. The resulting signal will thus be composed of sub-processes representing a small section of the image as a scan line, which sub-process is in turn divided into the number of scan processes required to represent all the separation colors.

Thus, in the latter control process, the drive devices must be arranged so that the drive device for the line scanner by means of the motor 10 retains the same in the various scanning positions while the drive device for the color separation device by means of the motor 36 moves the color filters in front of the line scanner 9 all the intended colors are scanned.

Thereafter, the motor 10 moves the line scanner one step and the motor 36 ensures that the color separation device is moved to a new initial position adapted to the new position of the line scanner for performing a new filter movement when scanning for the next color sequence.

As mentioned, the separation options include seven different options, three color filters for positive images, three color filters for negative images and an option to form a black and white signal. The device for moving the color separation slide is arranged to be adjustable for the following four different scanning options; 450 803 1. Color separation in three colors of a positive color image. In this case, the drive device moves the color separation slide with the three color filters for positive images in turn in front of the row scanner. 2. Color separation for the formation of three color signals and a black and white signal for a positive color image, such as for the production of four-color printing clichés. 3. Separation in three colors for a negative color image. 4. Separation in four steps for a negative color image.

In the apparatus shown and described, the control device for the coordinated movement of the line scanner and the color filter disc must be arranged for switching between switching for separation in the above-mentioned four different conditions. In case (1), the three filters, which are intended for color separation of positive images, are moved in turn in front of the line scanner, in case (2) the position of the black and white signal in the movement sequence is also included, in case (3) the movement between the three color filters for color separation of negative images and at the case (4), in addition to the latter filter, also includes the position for forming the black-and-white signal.

When using the apparatus with the scanning device according to Fig. 2, in the initial position the row scanner 9 is placed at one edge of the opening 22. After a suitable image 4 has been selected and inserted in the image holder 3, it is placed under the lighting device 2 and aligned by means of the projection window 14. until the desired setting is obtained. Then the mirror 12 is lowered, the image being projected within the aperture 22 with the focal plane in the plane 3 of the light-sensitive elements.

The order in which the colors are to be represented by the scan signal is determined so that the image reproduction in the receiver can take place in harmony with the scan in the transmitter. At the first scan, the filter for the first selected color is inserted inside the strips 26 (Fig. 2) and the scanning process is performed.

Then the color filter disc 25 is replaced with the next and the next scan takes place. The process is repeated until all colors have been represented, as mentioned three or more.

How the embodiment according to Fig. 3 can be used should have been apparent from the foregoing through the description of how the drive devices for the row scanner and the color separation device are arranged for specific control processes. Scanning according to the first described control process is substantially the same as that described above for the first embodiment. The only difference is really that the color filter changer device is shown as a machine for changing the color filters as the image is scanned in the number of complete processes required for color separation. On the receiving side, the processing of the signal does not differ from that which takes place in the first embodiment.

Thus, the image is built up in its entire surface in several steps where the colors are in turn added to each other to form the complete color image.

In the automatic design of the device, it is suitably adjustable between the described options for the control process and the filter selection.

In the second control process with the construction of the image section by section with all colors represented, a different reception technique is required. Thus, even at the reception, each section, preferably a single line, is now produced separately with the different colors added in turn to form a complete section. After that, the next section and line are built up until after reproduction of the last section, the image reproduction in the receiver is completely finished.

The form of the scanning process that is chosen also determines which type of receiver you have to work with. In the first type of scanning process, a black and white receiver can in principle be used and the color addition can be performed after the reception. In the first instance, however, a modified black and white receiver should be used where the only real change is that several successive registered complete signals are registered with different colors.

When registering a light-sensitive material by means of a light beam, this can easily be done through a color filter exchanger. When receiving according to the second scanning process, the receiver must be set up for the same control cycle, which means major changes in relation to a black and white receiver. On the other hand, in this control process, greater opportunity for precision in reproduction is gained. It is possible without difficulty to achieve very good precision in the positioning of the different color representations for the different determined lines, since all colors are registered line by line. In the first-mentioned control process, on the other hand, the difficulties of achieving such a positional agreement become greater by the scanning and reproduction device having to be moved synchronously several times over the total image area.

The last described embodiment according to Fig. 3, with the last described control process, should therefore represent the most developed and for some areas the most functionally advantageous technology.

According to the invention, each of the color filters only needs to consist of a narrow disc whose length corresponds to the height of the projected image. Since the color filter disc comes with the line scanner, its light-sensitive elements do not move along the surface of the color filter. Only a narrow central portion of the disk needs to be fully accurate in terms of refraction and color and there is no risk of the line scanner passing contaminated portions, which may be the case if a larger, relative to the stationary scanner stationary disk were to be used in the prior art.

In the most advanced embodiment according to Fig. 3, further gain is obtained with the last described control process, as indicated, good possibilities for very high precision in image reproduction. It is a further and no less advantage of the invention in addition to the previously described advantages of reducing the color filter surface.

Which form of the invention is chosen depends on the requirements set in the system in which the device according to the invention is to be used. If the received signal is to be used to produce a printing medium such as a number of color-separated clichés or stencils, three or four complete color-separated signals are transmitted. In this case, even the simplest form with manual change of the color filter discs can be used. Of course, the process is faster and with less risk of failure if the automatic device is used. In the direct production of a photographic color image in the receiving apparatus, the precision increases by better register keeping between the color-separated images if the second mentioned control process is applied by n; m 11 450 soz successive construction of the image line by line in all colors.

In this case, the automatic device must be used. The same is the case when generating a signal for presentation on a monitor via a memory. On a monitor of the catat ray tube type, the colors are built up together and in this case the latter control process is best suited.

As mentioned initially, the invention can also be used with scanning devices other than image transmitters. It is then adapted to the intended apparatus and can also otherwise have a different design than that shown without therefore departing from the inventive concept. Thus, the described line scanner with a row of light-sensitive elements along the scan line can be replaced by a dot scanner where a scan point is passed along a scan line to be moved to the next scan line and where to perform the same line scan. Use of such a methodology does not change the device according to the invention as here too the color filters can be elongated and extend along a line. In the embodiment of the device for automatically changing the color filters according to Fig. 3, two separate drive devices for the line scanner and for the color filters have been specified, which drive these elements in harmony according to a predetermined pattern. However, it is possible to design the device in such a way that a single drive device is present, but that the color filters are then so connected to this drive device that they can be moved relatively the same. This means that when scanning takes place during a process with an unchanged color filter, this is fixedly connected to the drive device for the line scanner, while when the color filter is to be switched, a special switching device performs a relative movement between the holding device for the color filters and the line scanner. The same scanning pattern can be achieved in this way as with separate drive devices.

Claims (10)

450 805 12 PATENT REQUIREMENTS Apparatus in apparatus for converting a color image presentation to an electrical signal and vice versa comprising a position (22) for presenting the image in an image plane in the form of a real image or a projected image, for example, a scanning device (7) with at least one light-sensitive element (9) arranged to be able to form an electrical signal, which represents the brightness of the image at the scanning point, a moving device (10, 20; 30, 36) for moving the element (9) over the image plane in a movement patterns comprising a number of scanning planes covering the image plane, wherein next to the scanning element (9) there are devices (26; 32), arranged for applying exchangeable color filters (25; 34) in front of the element in order to obtain a color separation of the image, so that several electrical signals representing the image, each relating to a particular color, which is separated from the image by the color filter, can be provided, characteristic n a d d a r a v, that the color filters (25; 34) each is substantially smaller than the image plane and is sized to substantially cover one or a few of said scan lines and that the holding device (26; 32) is supported by a moving device (10, 20; 30, 36) which is arranged to move the color filters together with the scanning element (9) in constant positional conformity with the same and the scanning lines gradually produced by the movement of the scanning element. Device according to claim 1, characterized in that the holding device for the color filters (25) consists of holding elements (26) arranged on a unit, which is arranged for supporting the scanning element (9), and,. _..___.__..._._._. æ. , f ..__.-._......___...._ ff V .._ ..,. "___",, fn 13 450 803 arranged for applying the color filters in position in accordance with the scanning line of the scanning element, which is located within the area of said unit. 3. A device according to claim 2, characterized in that the holding elements (26) for the color filters (25) are arranged for simultaneous holding of a single color filter and are arranged for replacing color filters manually. Device according to claim 1, characterized in that the holding device (32) for the color filters (34) is arranged to hold a plurality of color filters and is arranged for advancing these color filters in turn by moving the holding device. relative to the scan line of the scan element (9). 5. A device according to claim 4, characterized in that a control device is arranged to shift during the scanning process in a predetermined pattern the scanning and color filter holding device (32) so that the color felt during the scanning process. are brought in and in turn and the trajectories of the element (9) in relation to each other, pure (34) order is kept in accordance with the scanning lines produced gradually over the image plane. * 6. in that the control device is arranged to hold a first device according to claim 5, characterized by the color filters (34) in position corresponding to the scan line during a complete scan of the image to form a first complete color separation signal and to subsequently move and hold next color filter in position corresponding to the scan line during a complete scan of the image to form the next color separation signal until all the intended color separation signals have been formed. 7. - characterized in that the control device is arranged to hold a first color filter (34) the line during scanning of one or a limited number of g devices according to claim 5 or 6, characteristics - in positional conformity with scan lines constituting only a limited image section and thereafter holding a second color filter in position corresponding to the scan line when scanning the same image section as the 450 803 w preceding until all color separation signals for said image section are formed, after which the procedure is repeated for a second image section adjacent to all the image sections , scanned with respect to all colors in which the image is intended to be separated. Device according to one of Claims 5, 6 or 7, characterized in that the scanning element consists of a row scanner (9) which, by means of the displacement device (20), is arranged to be moved in its transverse direction over the image plane, that the holding device for the color filters (34) comprises a plate (32) with a number of openings (33), in which the color filters are inserted, which plate is arranged to move together with the line scanner and to be able to change position relative thereto, so that they various color filters supported by the plate can be switched forward in the middle position of the line scanner (9). Device according to claim 8, characterized in that the row scanner (9) and the holding device (32) for the color filters (34) each have a moving device (10, 20; 30, 36), which are arranged to the control device moves the row scanner and the holding device, respectively, in a coordinated manner and adapted to the scanning and color separation process. Device according to claim 8, characterized in that the row scanner (9) and the holding device (32) for the color filters (34) have a common moving device and in addition a changing device arranged for changing the position of the color filters (34) in relation to row scanner (9).