DE1919506A1 - Color television image pickup device and method for making the same - Google Patents

Description

The invention relates to a television picture pickup device and in particular a color television image pickup device with an image pickup tube, whose strip filter has a monochromatic part and a transparent part an inner surface of a faceplate (faceplate) is provided,

Usual in the conventional color television camera, hereinafter referred to as in the English language _area's called CTY camera having a stripe filter, the image is focused on a stripe filter 1 composed Sot (R) -, green (G) - and blue (B) -FiI-tern, which are arranged in strips and in which the image is then focused on a photoelectric converter surface of an image pickup tube 3, as shown schematically in FIG. With this arrangement, a high level of manufacturing engineering is required to produce R, G, and B colored strips, thus reducing the cost of an RGB colored strip.

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fenfliters 1 increased. Will also be such a RCffi-colored Filters built into an optical system, so it becomes necessary to use a relay lens 2, thereby creating the optical system gets more complicated. In another known CTV camera, the faceplate consists of an image pickup tube 3 instead from a relay lens made from fiber optics 4 and on top, is as in Figure 2 shown, a strip filter 1 attached. The use of such fiber optics results in a loss in the amount of light as well as a loss of resolution «In addition The manufacture of fiber optics requires a high level of skill.

According to the invention, a new and improved CTV image recording tube is therefore intended with a strip filter are proposed herein, which can be manufactured in a simple manner.

The invention also provides a method of manufacturing a CTV image pickup tube having a strip filter therein, which is easy to manufacture.

This is also intended for such a new, improved CTV image pickup tube an improved optical system can be proposed.

Finally, in the case of such a picture tube, the focal point of the picture pick-up tube should be automatically adjustable.

According to the invention, a CTV image pickup tube is provided comprising means for dividing light received through an objective lens into two parts along two run more discrete paths; a brightness or contrast image pickup tube is arranged and receives the light following a path and provides the brightness or contrast signals

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eels; one magenta fi3.terv / ird with light, which one of the other BaIm follows j applied; a chroma image pickup tube is provided near the magenta filter, this chroma « Citizenship image pickup tube includes a target with a faceplate at one end of a "vacuum vessel for receiving Liclit, with a strip filter on the inner surface of this ScMrmplatte is formed and alternately monochromatic Has parts and transparent parts; a transparent leader Film is coated on this strip filter and a photoelectric converting surface provided to receiving the light transmitted through the strip filter; Means are provided that output an electrical signal accordingly deriving the incident light from the photoelectric conversion surface by means of an electronic scanning beam; Finally, devices are also provided for the color television signals from the output signals of the two image pickup tubes allow to receive.

The invention will now be explained in more detail with reference to the accompanying drawings, in which

Figure 1 is a schematic representation of an embodiment of a known color television image recording device shows;

]? igur 2 is a similar illustration of another known one Color television image pickup device;

Figure 3 is a longitudinal section through a color television image pickup tube according to the invention;

Figure 4 is an enlarged section through part of the target used in the picture tube of Figure 5?

FIG. 5 is a top plan view of a portion of that shown in FIG shown targets?

Figure 6 is a schematic representation of an embodiment for a color television image pickup device according to the principle of the invention;

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Figure 7 is a block diagram of the image pickup device according to Figure 6;

FIG. 8 shows a graphic representation which helps to explain the mode of operation of the image recording device according to FIGS. 6 and 7? .

Figure 9 is a circuit diagram showing an embodiment of a color television image pickup device; and the

Figures 10A and 10B are diagrams showing the operation explain the device shown in FIG.

A first embodiment of the invention should now be included Referring to Figures 3 to 5 of the drawings, where Figure 3 is a longitudinal section through a vidicon * The general mode of operation and the construction of the electrodes of this vidicon are in general the same as those of a conventional vidicon, but the vidicon shown in FIG. 3 is distinguished by its special target. In particular are provided at one end of a vacuum envelope 11: a heater 12, a cathode 13, a first cylindrical grid electrode 14 »a second cylindrical grid electrode 15 and a third cylindrical grid electrode 16 in exactly the same way as in the conventional vidicon. A mesh field 17 is at one end of the third grid electrode 16 attached and forms an electron gun. On the inner surface of the faceplate 18 on the other side of the vacuum envelope 11 is a target 19 in the immediate vicinity of the mesh field 17 provided.

The target 19 is constructed in accordance with FIGS. 4 and 5 “in particular on the inner surface of the faceplate 18 are provided see a color stripe filter 21, a thin transparent glass plate 22, a transparent conductive layer 23? which serves as a signal electrode and a photoconductive one Layer 24 in that order. These form-

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the target 19. Compared to the usual color filter the color stripe filter 21 is not composed of plural kinds of color filters. On the basis of a conception that information . approximate the contrast or brightness signals in accordance with a green filter, according to the invention there is no green filter at all is used and the monochromatic parts 31 of the blue or red colored and transparent parts 32 are shown in Combined form of a strip, thus called the "Chromikon" Color stripe filter 21 is formed.

A method of manufacturing the target 19 is as follows:

After the surface of the pinned support 18 has been cleaned by washing it off, a red or blue stripe appears on it a photo-etching process or using a stripe mask. In particular, at least two substances from the group of light-transmitting substances with different refraction indices such as Magnesiumfluorld, Ceroxydj zinc sulfide etc. chosen and the chosen substances are alternately layered to form a strip filter with monochromatic parts 31 and transparent ones Parts 32 applied. The number and width of the strip are chosen so that the resulting filter acts as an interference filter acts and shows the required analytical and light-transmitting properties.

2.) A light-transmitting glass 22 is applied to the strip filter 21 thus produced and the light-transmitting glass is covered by a transparent conductive film. If desired, the light transmitting glass can be omitted. As the transparent conductive film, a tin oxide film, commonly known as "Nesa" (Registered Trade Mark), is commonly used ₉ which is manufactured

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by a Ithylalkohollösung is sprayed onto a to a temperature of 500 ⁰ C, for example, has been heated substrate. The ethyl alcohol solution contains stannous chloride to which a small amount of antimony chloride can optionally be added ITesafilme are unable to create satisfactory signal electrodes, '

You have now found the following procedure to work around this problem to solve.

The first method involves a yakiium deposition technique * So

is aluminum in vapor form on the strip filter up to one Thickness of about 50 to 1000 Å deposited. This deposition can easily be Torgsnoainen by using electricity through a tungsten wire around which an aluminum foil is wrapped. Although aluminum can be formed by a heavy metal such as gold or silver, aluminum appears to be due to it best suited to its transparency and electrical conductivity,

The second process can be seen in atomization or spraying technology. For example, a sealed flask is filled with an inert gas at a pressure of 10 ^J mm Hg and has an cathode electrode made of a platinum sheet and an anode electrode made of a metal sheet, against which the glass pane on the strip filter is brought into intimate contact. These two cathodes are arranged inside the sealed vessel. The dimensions of the platinum sheet can be 15 cm χ 15 cm, those of the metal «»

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bleelies at 20 cm χ 20 cm and the distance between these can be 15 cm. Under these conditions, a voltage of 1500 V is applied to the two electrodes, whereby. Platinum on the anode, which is the strip filter, is atomized. Platinum films with a thickness of 50 to 900 Å show adequate conductivity and very good light transmission properties.

3.) Upon completion of the above-mentioned process steps, a photoconductor, for example anti-ion trisulphide or lead oxide, is deposited on the transparent conductive film by vacuum deposition, for example. 3ei Antiniontrisulfiö throws a porous layer and a solid layer in succession. clit or a solid layer and a porous sliiclit and again a solid layer laminated on the f-ranspare.nten conductive film, - The expression "porous layer ¹⁵ " is never used here _t means a layer which consists of relatively coarse particles, which are deposited as a vapor under a relatively low vacuum, whereas the term "solid layer" means a dense or glassy layer consisting of very fine particles which are deposited as a vapor under a high vacuum Layers are well known per se and it is not necessary to describe them in detail, whereas lead oxide is provided with a nip diode structure or a multilayer structure, the intermediate or boundary surfaces serving as electrical barriers to increase the dark current photoconductive layers with the required analysis sensitivity can be made.

The photoconductors can be replaced by pnotoelectron-emitting substances. All examples of such substances

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Multi-alkali photosensitive antimony, cesium and silver bismuth surfaces should be named.

The target produced in this way is attached to the one shown in FIG Vidicon shown is provided and completes a CTV image pickup tube. With such an image pickup tube, an image of an object is on the color stripe filter through a Objective lens, not shown, is focused and that through the monochromatic (for example red) parts and the transparent ones Light transmitted to parts of the strip filter hits the photoconductive surface through the signal electrode, thereby exciting the photoconductive surface. The excited photoconductor converts the color information into electrical signals a function of time when it is scanned by an electron beam from the electrode gun « This makes it possible to use discrete color signals through frequency separation devices or to receive time gates »

As described above, according to the present invention, the above-mentioned disadvantages can be solved by providing a GTY image pickup tube composed of: a vacuum piston; a color stripe filter contained in this flask and containing a stripe of a color filter; see a photoelektri- W, converter area contained in the flask, which receives the transmitted light through the filter strip and deriving electrical signals converted by the transducer surface by electron beam scanning.

The CTV image pickup tube is advantageous in the following ways:

1,) The color stripe filter can be easily manufactured because it only becomes necessary, sequentially To arrange filters of one color in the form of a stripe. Of the

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The percentage of acceptable products can thus be increased by reducing the cost.

2.) Since there are no special and difficult manufacturing techniques in Prague ©, the image pick-up tube can be mass-produced.

The above description is given using a yidicon, Of course, the invention can be applied to any type of clay electron tube, especially a picture orthicon » which light signals can convert into electrical signals! »And is able to derive electrical signals by means of an electron scanning beam

For example, the color stripe filter with a filter strip of a part between a faceplate and a photoelectric transducer surface of a picture orthicon swischsngesehalt be held. With this arrangement, this is supported by the Color stripe filters transmit light into electrical signals converted by the photoelectric surface; Photoelectrons are focused on the target at the image section and electrical signals on the target can be derived »by scanning the target with an electron beam.

According to the example described above, according to which the color stripe filter is formed to be a rectangular one Has a shape corresponding to the scanning surface of the electron beam, which means that no color filter is formed on the periphery of the shield support, the danger may arise a flaking of the color filter on the peripheral edge plate for The point of manufacture should be avoided.

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Figures 6 and 7 show an example of an image recording device, which works with the image pickup tube shown in FIGS. 3 to 5 as a chrominance image pickup tube.

Light incident on an objective lens 4-1 is divided into two paths or parts of a half mirror 42 ₉ one part is focused on a photoconductive surface of a brightness receiving tube 44, for example a vidicon known per se via a brightness or contrast fliter, while the other part is focused on a ' photoconductive surface 50 P is focused by a magenta filter 45, which transmits uniformly only blue or red, this training belonging to a vidicon in which a monochromatic stripe filter 49 for red or blue, for example, between elaen faceplate 47 of a chrominance image pickup tube _9, for example a vidicon, and a signal electrode 48 in between.

When Inabesomöere an optical image is projected from the half mirror 42 ataf the lägestafliter 45 which transmits red and blue light and when a red stripe filter is used in the OtaDiaajzität image pickup tube 46? The result is a mixed image of the hagenta filter and the red stripe filter on the photoelectric interface of the chroma image recording tube 46. Since the transmission or permeability of the stripe filter is still not uniform, there is a difference in the light energy between the transparent and red parts of the strip for deep red colors, whereby the output, which must necessarily be compensated, is modulated in this way

The circuit diagram for the image recording device ma @ fe Wlgar 6 is shown in FIG.

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In particular, the output of the brightness or contrast "image pickup tube 44 is connected to a correction circuit or amplifier through an amplifier 61. The output from the correction circuit is divided into two parts, one is given to the output terminal for the contrast or brightness signal, the other to the input of a low-pass filter 63.

The output terminal of the chroma image pickup tube or a vidicon 46 with a red-colored striped filter is sent to a correction circuit 65 via a striped filter 64. Of the Output from the correction circuit 65 is divided into two parts, one is sent to a matrix circuit 67 through a mederpass filter 66 while the other is given to the same matrix circuit through a band pass filter 68 and a detector 69 is given.

The red signal output from the matrix circuit 67 is with a Output terminal connected through a differential amplifier 70 while the blue signal output is passed through to an output terminal a differential amplifier 71 is connected.

The output from the low pass filter 63 is to the differential amplifier 70 and 71 connected.

The device shown in Figures 6 and 7 operates as follows:

An optical image of an object that is not shown is on the photoconductive surfaces of the contrast or brightness pick-up tube 44 and the ear capacitance pick-up tube 46 focused by an objective lens 41 and a half mirror 42. In the optical path to the focal plane are provided: a contrast corrector filter 43, a magenta filter 45 and a Red stripe filter 49.

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The result is that the optical image passed through the contrast correction filter. 43 is transmitted, is converted into electrical signals by the contrast image pick-up tube 44 in accordance with the television technique known per se. The red component and the blue component of the light image alone are transmitted through the magenta filter 45. The transmitted light hits the red stripe filter 49 on the dePi faceplate 47 of the yidikon. Since the filter 49 has a stripe of the red filter parts and transparent parts, when passing through the color stripe filter 49, the light transmitted through the magenta filter 45 hits the photoconductive surface 50 of the tidicon 46, with a component proportional to the energy of the red and blue light a and one component is proportional to the energy of the red light alone. By scanning the photoconductive surface 50 with an electron beam in a manner known per se, a. Vidicon output consisting of alternating electrical signals of an optical image proportional to red and blue and an optical image proportional to the energy of the red. The result is that the red light in the low frequency component, which is insensitive to the deviation of these signals due to the color stripe, still includes the transmitted light and has sensitivity over its entire energy range, while the blue light for an output corresponding to half the energy ensures _o In the high frequency component jedochniie difference between an instantaneous value of the red and blue and the red value appears) · than the amplitude, so that the signals of the blue light are generated alone. However, since a certain part of the red light passes through the filter twice and the rest only once, there is a difference between their outputs, whereby the red signal is mixed in the high-frequency component. Although this red signal has a small value £ , a signal corresponding to FIG. 8 is off as an output

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the Gbxoaasitetsblldauffachuhr available »

Sa the ver, fc τοη ο is constant, it becomes possible to red and blue signals are obtained by the matrix circuit 67 shown in FIG.

The output signal according to * Igur 8 from the chroma vidicon 46 is increased to a desired value and then its frequency characteristic and (lascharacteristic is corrected by a correction circuit 65 in the same way as in the case of the confessed Tldikoauegang. Then the signal becomes old one Frequency distribution according to FIG. 8 is supplied to a leather pass filter 66 and a band pass filter 68.

The low-pass filter 66 lets a signal component R + -B la Flederfrequensband of Figure 8 through, whereas the band-pass filter 68 lets through a signal component B + d * R in the high frequency band. Through the filter 66 bsw. 68 signals read through are given to the matrix circuit 67, but the component B + J R in the high-frequency band is given to the matrix circuit after it has been detected by a detector 69. The matrix circuit takes over the following work of the primary transformationa

Is gate suspended that

2
■ <f R + B

Then it will be

B m

¹ - 2

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1 - ί

The operation is done by the matrix circuit to red i'm getting blue signals. These color signals are given to differential amplifiers 70 and 71, respectively, which represent the differences between a low frequency component of the contrast output signal Y from the contrast vidicon 44 and the color signals R and B are amplified, producing output color signals R-Y and B-Y, respectively.

Thus, according to this embodiment, an Earbfernsehblldaufnahmeeinrichtung is created, which consists of an image recording device for generating contrast signals _{s of} an image recording tube with a monochromatic color stripe filter on the photoelectric transducer surface in the Yakuumkolben and facilities for generating τοη color television color signals from the output signal of the image recording tube.

The optical system of the well-known Parbfernsehbildaufnahmeeinriehtung has a long light path and is of complicated construction, since we worked with a relay lens according to the invention However, it becomes possible to simplify the optical system as follows. Since it is possible to leave out the relay lens, it becomes possible to adjust the characteristics such as the quantity of ambient light, the limitation for the objective lens opening and to mend a loss of light quantity, etc.

The inventive measure leads darüberliinaus au award · = ■ "actual values color cameras smaller G-ize and low weight due to the simplified optical. System high quality vmü contributes sur widespread use of Farbfernssh-"

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Tape recorders and color cameras that operate outdoors become at.

According to the embodiment described, a vidicon was used as a Image pickup device used. It should be noted that any other suitable converter device capable of converting light signals into electrical signals, can be used as a picture orthicon.

Although there was a stepping through an objective lens Half mirrors arranged in a light path are used to split the light into two paths, any other device used in the Is able to divide light into two paths, but can also be used, for example a dichroic prism. Becomes a dichroic or two-color prism according to the above If the embodiment is used for the quantity of light, it becomes possible to use the correction filter 43 and the magenta filter 45 to omit or to use simpler filters.

As an example of the application of the image pickup device with an image pickup tube according to Figures 3 to 5 »the following embodiment is mentioned, according to which the focus of an electronic lens system is given by automatically adjusting the voltage of a collector electrode so that the high-frequency output is at a maximum.

This can be achieved by a regulating or control circuit for the embodiment shown in FIGS. 6 and 7, the adjusts the voltage of the focusing electrode in such a way that that the high frequency from output is at a maximum.

Details for such an application are provided below will be described with reference to Figs.

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A light image of an object 80 is projected onto a half mirror 82 through an objective lens 81 and divided into two paths, one is focused on a photoelectric surface of a contrast or brightness image pickup tube 83, while the other is focused through a magenta filter 84 on the photoelectric surface of an earomacity image pickup tube 85 containing a strip filter according to the invention. The output signals from the chromacity receiver tube are the so-called frequency-separated signals, in which the signal component R + rß is in the medium frequency band and the signal component B is in the high frequency band. These output signals are applied to a frequency separator 88 through an amplifier 86 and a switching circuit 87. The signal component R + -B divided by a low-pass filter 89 and the signal component divided by a band-pass filter 90 are supplied to a detector 91. Thereafter, these signal components B and R + kB are acted upon by a matrix circuit 92, whereby B and R are supplied to output signals. The Y output from the luminance and contrast image pickup tube 83 is given to a low pass filter 95 through an amplifier 93 and a correction circuit 94, and is then fed to mixers 96 and 97, respectively, to convert R-Y and B according to the R and B signals - Y color f eras to form ehe ignale.

The output component (the output obtained at the time of tension application; described later) from the band-pass filter 90 is coupled to a synchronous detector 100 via an amplifier 98 and a mederpass filter 99 and is synchronous determined with the search voltage from a flip-flop 101. The search voltage signal provides a horizontal synchronizing signal H to the flip-flop circuit 101 and assumes a rectangular waveform that is positive or negative at every horizontal Synchronization signal is. This search voltage is on

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The synchronous detector 100 and also a focusing electrode 103 of the image pickup tube 85 are placed via a mixer 102.

- The output from the synchronous detector 100 is a phase reversal device 105 via a loop filter 104 to reverse the phase and then to the base electrode of an npn transistor 107, for example from the source circuit 106 with a focusing electrode. This source 106 consists of one Direct current source 109, one end of which is connected to ground and the other end to the collector electrode of transistor 107 is connected via a resistor 108, the emitter electrode of the transistor being connected directly to ground. Furthermore is the collector electrode to mixer 102 via a DC power source 110 connected. The output from the phase inverter 105 is sent to the focusing electrode 103 of the image pickup tube 85 is applied through a transistor 107, the DC power source and the mixer 102.

A rectangular waveform search voltage signal generated by the flip-flop circuit is given to the focusing electrode 103 via the mixer 102. If, as shown in Figures 10A and 10B, the focusing electrode voltage assumes a position a in which the focusing electrode voltage is lower than the voltage corresponding to the maximum output voltage in the high frequency band _s , the phase of the output from the image pickup tube 85 becomes the same as the d © s search voltage output from the flip-flop circuit 101. If, on the other hand, the focussing Herdönspanmißg d @ ü value £ increases above the value b corresponding to the massive initial position © i & s, the phase of the output from the picture tube 85 becomes. vice versa to that of the search voltage output from the flip-flop circuit 101. In position b corresponding to the maximum focussing lead electrode voltage, there is no corresponding output

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the rectangular search voltage is available from the pickup tube.If the rectangular output voltage, which is of the same or opposite phase with respect to the voltage signal from the pickup tube 35, is derived, then this output is supplied to a Mederpass filter 99 via a separator 88, the bandpass filter and the amplifier 98. The energy of the square wave signal is then averaged over a period of the horizontal synchronizing signal (a period of the visual voltage) and the signal is applied to the synchronous detector 100, which is to be determined by the visual voltage from the flip-flop circuit 101. The synchronous detector compares the phase of the square wave signal and that of the search signal voltage xmä. supplies a positive voltage when they are in phase, but a negative phase when they are out of phase. The phase of this positive or negative voltage will last. reversed a phase inverter 105 and then applied to an ice cream 106 for the focusing electrode. If beiö © set on AEEN synchronous detector signals is phase are so set Spannimg's oils to the focusing electrode high, whereas ,, if they save. Phase, the voltage applied to the focusing electrode 103 is low. Reaches the maximum der'Ausgang iss Hoekfrequenzband b inclined as in Figure 10A and 10B ₉ because there is no output from the image pickup tube 85 is provided so _s i? Ird the resultant of the Suehspannung to the S ^ efessuletektor set 100 ;, this detector is no output ,, t? © ljei the output in the high frequency band is left at the maximum value. Thus, the occurrence of the so-called UnseMiris-EustaadeS caused by an excessively low © äsr high focus = de electrode voltage - positive terMaöert xierde & j, so that always satisfactory images are obtained! - / earth »

Pat ant claims

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Claims (2)

Case 430143-3 PATENT CLAIMS Color television image pick-up tube with a vacuum coltoene, one at one end of the vacuum envelope for receiving incident light arranged faceplate, one on the Inner surface of the faceplate formed target and facilities for scanning the target by means of an electron beam and for deriving electrical signals accordingly the incident light thereof, characterized in that # the target (19) consists of a strip filter (21) an alternative arrangement of monochromatic areas (31) and transparent areas (32) is constructed that a transparent conductive film (23) is applied as a coating on the strip filter and that a photoelectric conversion surface (24) is provided within this film for receiving the light transmitted through the strip filter. 2.) A method of manufacturing a color television image pickup tube, in which a vacuum envelope with at one end of the Valcuum piston formed faceplate is produced, a Target is formed on the inner surface of the faceplate and the target is scanned by means of an electron beam and electrical signals corresponding to the incident light are derived therefrom, characterized in that a strip filter consisting of an alternating arrangement of monochromatic and transparent areas to form the target Areas is provided, a transparent conductive film is applied as a coating on the strip filter and a photoelectric converting surface is placed inside the film to prevent the transmitted through the strip filter To receive light. X-X-X-3C-3C 909848/0598