WO1993003573A1

WO1993003573A1 - Image recorder

Info

Publication number: WO1993003573A1
Application number: PCT/EP1992/001800
Authority: WO
Inventors: Josef Kirmeier
Original assignee: Josef Kirmeier
Priority date: 1991-08-07
Filing date: 1992-08-07
Publication date: 1993-02-18
Also published as: EP0597955A1; DE4126187A1

Abstract

An image recorder has an usual camera tube (2) for video recordings and electronic circuits (12-15) connected downstream thereof. The device can be controllably (22) operated so that it supplies signals that are adapted to a printer connection (17) and if necessary to other connections (16, 18).

Description

Image acquisition device

For electronic recording of images, the electronic image recording tubes used for conventional television recording technology have been known for decades. In the recent past, video cameras have been used primarily for the non-professional sector. e.g. known under the name "camcorder", with which a wide range of users make magnetic tape recordings, instead of recording (photo) films. For the latter video cameras, semiconductor CCD circuits are used as optoelectronic recording elements, with which the current image is recorded line by line and the electrical analog signal to be obtained is stored serially on the magnetic tape, again as an analog signal. It is also known to connect such a camera directly to the video input of a television set for immediate playback.

A completely different kind of "picture taking" is the copying of documents. This is about reproducing the regular two-dimensional image of a template as a two-dimensional copy on a sheet of paper. For this purpose, electrostatically operating copying machines are used, in which a light-electric, rapidly rotating drum is used for optoelectrical recording and for the immediately subsequent transfer of the electrostatic charge image onto a sheet of paper. The present invention relates to a technique in which images of two- or three-dimensional objects are to be recorded, of which copies are to be made or whose information content is to be provided as a digitalized image information signal at an electrical connection. Field of application of a device relating to the present invention is, for example, the production of copies from books, foils and the like in particular. The latter copies, for example, can only be made with great difficulty by means of an electrostatic copier of a known type. For example, the weight of such books from which copies are to be made is a major disadvantage of making copies using conventional technology. Details of this and also other areas of application for the present invention are evident from the older, unpublished patent application P 41 13 594.6 of April 24, 1991 by the same inventor as the present application. The description content of the aforementioned older application is thus made part of the present description of the invention.

The present invention is an image pickup device having the features set out in claim 1. Further refinements and developments of the invention emerge from the associated subclaims.

For the present invention, use has been made of an electronic vacuum image pick-up tube with an analog electrical output signal which is known in principle and which supplies an analog image signal. Such tubes are known, for example, as Newicon, Super Orticon and the like. Such tubes contain a photoelectrically operating screen on which the two-dimensional image of a two-dimensional or three-dimensional object is to be optically reproduced. The photoelectric screen of the tube is scanned inside the evacuated tube using an electron beam, usually line by line of the image. The electrical scanning signal is immediately available in analog form at the signal output of the tube. These properties of the tube are primarily adapted for television playback, in particular moving images. For the present invention, however, in which copies are to be made differently, provision is made for this image recording tube to be followed by an electronic device which comprises a preamplifier, an analog / digital converter, an image memory and a signal output unit in series connection. At the output of this device, a digitized image signal corresponding to the analog signal output of the tube is obtained.

The device according to the invention further comprises a process control device which can be controlled from a keypad. With this process control device, the device downstream of the tube can be controlled as is suitable for the individual intended application of the invention. From the keypad the process control device can be used to control the amplification of the preamplifier, the deflection system of the tube, the image memory, the lighting and the like, namely the lighting that is required in the individual case in order to use the image recording device according to the invention to be able to record the template.

The analog / digital converter contained in the device connected downstream of the tube can expediently also be a circuit comprising a comparator and a digital / analog converter.

Further explanations of the invention are given for the sake of simplicity with reference to the attached FIGS. 1 and 2, of which FIG. 1 shows an overall picture of an embodiment of the invention and FIG. 2 shows the circuit of comparator and converter already mentioned above.

The image recording device designated by 1 in FIG. 1 comprises the actual image recording tube 2. As said, an already available tube can be used for this. 3 and 4 denote a (horizontally scanning) cell deflection system and a (vertically scanning) image deflection system. In the case of magnetic deflection, these are known to be systems integrated with one another in a coil arrangement. With 5 and 6 are deflection amplifiers and with 7 and 8 are still referred to below to be described digital / analog converter. The output terminal 11 of the tube 2 is connected to the input of a preamplifier 12, which is followed by a circuit 13 which is an analog / digital converter or a circuit according to FIG. 2. The output of this circuit 13 is followed by an image memory 14 and this is followed by the output unit 15 with the output connections 16, 17 and 18.

The process control device already mentioned is designated by 21, the outputs 22 to 25 of which are connected to the converters 7 and 8 as well as to the preamplifier 12 and the circuit 13.

Further outputs 26 and 27 of the process control device serve to control the lighting 31 or the output unit 15 which may be required. The keypad 40, which is connected to the process control device 21 or is a component thereof, contains the keys required for control. Remote control or control for which input 121 is provided can also be provided (in addition).

The function of a device according to FIG. 1 is that the analog output signal K is first amplified in the preamplifier 12, the degree of amplification of which can already be selected via the process control device or its output 24. The output signal of the preamplifier 12 controlled in this way goes into the analog / digital converter 13, in which the digitization of the analog or gray values of the output signal K of the tube 2 takes place. Again, this mode of operation can be controlled from the process control device or from the keypad.

The output signal V of the circuit 13 is sent to an image memory 14, which can carry out intermediate storage adapted to the individual case. The output signal of the output unit can be at the connection 16 an output signal corresponding to the SCSI standard, which is further processed accordingly, for example transmitted by fax can be. At output 17 l the output unit delivers an output signal adapted to the operation of a (graphic) printer. Finally, the output unit 15 can also have an output 18, from which a video signal (bypassing the corresponding circuit point mentioned above) can also be taken, which can be given directly to a television set, for example.

FIG. 2 shows a circuit replacing the analog / digital converter 13 of FIG. 1 with a digital / analog converter 113 and a comparator 213 in the circuit-like connection with one another as indicated. The converter 113 supplies the graded reference voltage values for the threshold value settings of the comparator 213. The output signal is again a digitized signal.

The preamplifier 12 can be operated as a linear amplifier, but can also be operated as a positive or negative logarithmic amplifier, it being possible for the various functions of the amplifier 12 to be switched by the process control device 21.

An example of an operating mode of a device according to the invention is that in which the electron beam used to scan the individual pixels of the screen 102 of the tube 2 is in horizontal or horizontal direction. Line direction scans 3500 pixels. With the step-wise deflection signal, which is supplied by the converter 7 to the horizontal deflection, the electron beam can be shifted discontinuously from pixel to pixel of the cell and the discrete pixel signal (as an analog signal) can be recorded and digitized in stage 13. The horizontal deflection therefore does not take place in an analog-linear manner, but in steps corresponding to the step-by-step signal of the digital / analog converter 7 controlled by the process control device 21. The switching tents of this converter 7 are connected via the process control device 21 to the converter device 13 or of the converter device according to FIG. 2, coupled for the signal of the pixel information (unless the mode of operation for the analog output signal on

Output connection 18 of the output unit 15 is requested and set). As described in relation to the horizontal, the deflection of the electron beam is operated in a vertical manner. For example, 2500 cells are provided. The converter 8 supplies the correspondingly graduated deflection signal for this vertical deflection or deflection of the lines among one another. As already mentioned, in the case of magnetic deflection with an integrated xy coil deflection system, the corresponding codification for pixel scanning is to be provided.

In order to obtain a correspondingly high pixel resolution, it is advisable to work with a reduced beam intensity of the tube, which enables sharper focusing. In principle, this results in a lower recording sensitivity of the tube 2 or its screen 102. However, contrary to the intended use of such an image pickup tube 2, this is not a problem for the task envisaged for the invention, since when the invention is used as intended, sufficient light is always available, possibly through the illumination device 31.

The use of digital / analog converters provided in the invention as a source for the deflection signals or beam positions to be set for the individual pixels is a very advantageous measure in connection with the invention, since it enables very precisely positioned and repeatable scanning of the individual pixels with the help of the electron beam is possible. This is an important aspect in the invention, since digital output signal is required at connections 16 and 17 of the output unit.

Insofar as this is necessary, path length compensation of the electron beam can be provided for different path lengths with respect to a point in the middle and one at the edge of the image field. This can be done by modulating the timing of the converter in question.

In order to comply with standards in particular, provision can be made to use the analog / digital converter 13 or the circuit combination according to FIG. 2 to generate an 8-bit or a 10-bit signal corresponding to 256 or 1024 gray levels. The pixel information of the individual pixels, the scanning of which is coordinated with the aid of the process control device, can be amplified linearly or logarithmically with the aid of the preamplifier 12, namely positive-logarithmic or negative-logarithmic. With the logarithmically controlled amplification, a gray value increase or decrease can be carried out, as can be useful in special applications. It is advisable to provide pulsed illumination of the original, namely in synchronism with the scanning of the individual pixels, which, as described above, controlled by the process control device 21, is carried out in a discontinuous manner (unusual for such a recording tube) can be. The lighting sources that can be used for this must be discharge lamps that can be modulated very quickly, since a clock frequency of up to 9 MHz can be considered or must be taken into account. However, since such lamps emit a lot of heat, fast fluorescent tubes can also be used, which are operated at 1 MHz. The operation of the process control device 21 ensures the necessary synchronization between the lighting cycle and the deflection of the electron beam in the tube. It should be noted that, however, it is also possible to use sources of illumination with a voltage or continuous wave mode. In order to report color blindness of the image recording device according to the invention, care must be taken that the artificial lighting sources used provide a correspondingly complete light spectrum.

Insofar as sufficient illumination brightness of the template can be achieved in individual cases with natural light, the artificial lighting described above can be dispensed with.

It must be ensured that the lighting, artificial or natural, of the original is such that the local lighting density is sufficiently the same. If this is not the case anyway, it is advisable to provide a diffusing screen with which the light incident on the original is not mattered. Such a lens can be a plastic glass with, for example, a pyramidal roughening of its surface.

An image recording device according to the invention has compared to the

Devices available in the prior art are preferred, for the intended application, in particular the creation of copies, with your downstream device and the control directly

To deliver usable output signals, e.g. in the SCSI standard or for direct control of a conventional printer. With the invention, a graphic printer (laser printer, matrix printer, thermal printer and the like) can be controlled directly. When using a

Laser printer, the video interface of the printer can also be controlled directly, so that e.g. the printout of the image taken by the tube 2 can be delivered within 5 seconds (the latter depending on the special design of such a printer).

The device according to the invention does not require any additional computer, no special software and / or other units which are used for

computer signal processing are common.

The device according to the invention can be used as a camera wherever image acquisition and reproduction (as a copy) with a resolution of 300 dpi, based on the A4 format, is sufficient. An advantage over a line scan camera is that the device according to the invention can carry out the entire image acquisition in a fraction of a second. The invention is therefore of particular importance there and its application is particularly advantageous when very fast image acquisition with digital output

Information is required.

The device according to the invention has the special feature that it has a direct connection for a printer, namely a connection with a digital output signal, and the possibility for a direct connection

Operation via the keypad 40. A data modem can be integrated into the device according to the invention, so that this device can also be operated remotely via a data line. In particular, the device according to the invention is suitable, the

Output image information so that this information can be transmitted directly as a fax. The camera can not only be operated locally using the keypad, but also remotely.

The digital signal is available at the SCSI data output of the device according to the invention for the computer used. Since the data are retrieved from an image memory of this device, an identical address assignment takes place in the working memory of the computer, which is reproducible.

Furthermore, no special boards with software or special software for operating the device are required to operate the device. The

Data is transferred via a standard SCSI interface and can therefore be connected directly to any computer. The internal command set of the device enables direct integration into the respective analysis software with the control of various operating functions.

The resolution of the device according to the invention is many times higher (up to 3600 x 3600 pixels) than with cameras already on the market, but has the same frame rate.

With a high-level driver, the digital signals can also be transmitted without problems and over long distances.

A device according to the invention can also be used in measurement technology with non-contact measurement. The internal image memory 14 is with the digital deflection 7, 8 and the image conversion 13 via the

Process controller 21 firmly linked. This ensures that the first digitized pixel always occupies the first bit in the image memory. This is an essential prerequisite for accurate, reproducible measurements and evaluations in measurement technology. The device according to the invention is to be used as part of an autonomous image measurement analysis system. The measurement result is reproducible because the first recorded and digitized Dot, whatever the defined memory address is, what is required for exact, reproducible measurement and analysis.

Besides the actual image analysis software, it is not a special one

Driver software required for the digitizing board. Working in harsh operating conditions, for example in the vicinity of

Machines, possible.

The resolution of known devices with 640 x 572 or 1024 x 1024 pixels is not sufficient enough for many measurement tasks with regard to the required accuracy. There are CCD area sensors with 2048 x 2048 pixels, but these are very expensive due to the production-related high error rate and have not yet been implemented in cameras. Nor do they offer the properties of the device according to the invention.

A device according to the invention advantageously has, for example

compared to a video camera as discussed at the beginning, a small and therefore handy size.

Claims

PATENT ADDRESS

1. Image recording device with an electronic vacuum imaging tube (2) with a photoelectric screen (102) and with one

Electron beam system with deflection system (3, 4) for scanning the area of this screen (102), with which an analog image signal (K) can be obtained at the output connection (11) of the image pickup tube (2), with one of these image pickup tubes (2)

Device with a preamplifier (12), a circuit (13) for digitizing an analog signal, an image memory (14) and a signal output unit (15), which in this sequence are connected in series between the signal output (11) of the image pickup tube (2) and the Signal output (16,17) of this device are inserted and with a process control device (21) which can be controlled by an operator (40) and with which the operation of the amplifier (12), the deflection system (3,4) of the circuit (13) for digitization and the image memory (14) is to be controlled.

2. Apparatus according to claim 1, in which an illumination device (31) for illuminating the image tube (2) to be recorded is additionally provided, this illumination device (31) being controllably connected to the process control device (21).

3. Apparatus according to claim 1 or 2, wherein the circuit (13) for digitization inserted between the amplifier (12) and the image memory (14) comprises a circuit (Figure 2) which contains a comparator (213) as a threshold discriminator which receives the continuously changing reference voltage signal from a digital / analog converter (113).

4. The device according to claim 3,

in which the digital / analog converter (113) has an output connection for an analog signal of the recorded image information.

5. Device according to one of claims 1 to 4,

with a keypad (40) which is connected to the process control device (21) for operating the process control.

6. Device according to one of claims 1 to 5,

with (additionally) an input (121) of the process control device (21) for remote control of the process control.

7. Device according to one of claims 1 to 6,

with both an output connection (17) for the digital input of a printer and an output connection (16), from which a SCSI-standardized digital signal can be found, which are each provided on the output unit (15).

8. Operation of an image recording device according to one of claims 1 to 7,

as a copying device for the production of facsimile print copies corresponding to the original.

9. Operation of a device according to one of claims 1 to 7 as a facsimile recording device for information to be transmitted in fax operation.

10. Operation of a device according to one of claims 1 to 7 as a recording device to be connected to the video input of a conventional television set.