TW493195B - Tracking cathode ray tube circuit having a modulator demodulator - Google Patents

Abstract

A tracking index cathode ray tube circuit is described, comprising tracking means connected to a shadowmaskless tracking cathode ray tube for deriving a tracking signal therefrom, where the tracking means comprises a modulator demodulator circuit. The tracking signal from the CRT tube is thus modulated, AC coupled to a low voltage and demodulated to obtain a baseband tracking signal for use as a control signal for the electron beam spots on the screen of the CRT tube.

Description

493195 V. Description of the invention (1) The present invention relates to a tracking cathode ray tube circuit, which includes a tracking # device from which a tracking signal is obtained and is connected to a shadowless cathode ray tube. The patent G B-1 40 0 0 6 1 can be learned that this type of tracking Thai cathode ray tube circuit, also known as the indicator tube. Disclosed in this article is a so-called shadowless cathode ray tube (CRT), in which a feedback control loop can control the correct landing position of the electron beam on its front panel. The position of this fixed point can be measured using a guide structure or sensor positioned on the inside of the front plate. When scanning a certain point along the road, the signal of chasing 5 images will increase depending on one of the fixed points. You can use this chase signal to generate a certain point position output signal for the deflector to keep the fixed point on the road. Designing the rail structure in this way can produce a modulating pursuit signal with a very high voltage relative to ground. It is well known that a guide structure with a constant hand-tilt pitch results in an error signal that can be composed of amplitude-modulated signals at the carrier frequency. Then there is no confusion to distinguish the error signal from the video modulation. However, one of the disadvantages of the known shadowless masking | cathode ray tube circuit is: In addition to the shape of the chasing structure, the frequency modulation and modulation depth must be properly selected / selected relative to the video modulation in order to prevent the winter Alas, like. It is therefore an object of the present invention to provide a cathode ray tube circuit with fewer key structural statistics and internal shapes without causing artifacts or requiring fine tuning of internal installation and prescribed modulation quantity and characteristics. To achieve this, according to the present invention, an image-recovering cathode ray tube circuit is characterized in that the image-recovering device includes a modulator and a demodulator circuit. Pursuing J Elephant According to the Invention

493195 V. Description of the invention (2) One of the advantages of the CRT circuit is: internally, there is no shadow mask to track the f. The CRT tube does not need to be adjusted because an unmodulated / basic band is chasing the image signal The shadow mask is created by chasing the CRT tube. It is said to provide a tracking image device outside the tracking CRT tube, and it also includes a modulator demodulator device that generates a modulation tracking signal, which can advantageously and easily down-convert this modulation tracking 5 # signal from the anode potential ( Typically 25 kV) to ground potential. An easy-to-implement example of the XRT circuit of the present invention is characterized in that the modulator connected to the shadowless cathode-ray tube is separated from the demodulator by a first AC coupling. This AC coupling is effectively a conventional type, for example, an electrical, magnetic, optical or acoustic coupling. A further example of a tracking CRT circuit according to the present invention is characterized in that the tracking device includes an oscillator coupled to one of the modulator and the demodulator. One of the advantages of the sCRT circuit of the present invention is that only one oscillator is needed to drive the modulator and demodulator. A further example of a CRT circuit according to the invention is characterized in that the oscillator is connected to the modulator and coupled to the demodulator via a second AC coupling. An advantage of this example of the tracking circuit of the present invention is that the possible frequency and phase problems can be eliminated, because the phase difference on the 黾 A C coupler of the tracking signal and the oscillator signal is equal, respectively. This provides the possibility of one of the demodulator's simple and correct synchronization detection. A further example of the index CRT control circuit is characterized in that the oscillator is coupled to a DC / AC converter, this converter must also be coupled to a DC power source and its converter output is coupled to a second AC coupler. According to this example, the relevant AC coupler can simultaneously provide a supply voltage and separately provide a modulated or modulated signal.

493195 V. Description of the Invention (3) No additional circuit required to demodulator or modulator. Advantageously, several variants and examples of the 5 | crt circuit are feasible. AC shore coupling systems are once again customary, such as a capacitive, inductive, optical, or acoustic coupling. Generally analog modulations include different modulation types, such as AM, FM PM, DSB, SSB, VSB, FSK, and so on. According to a further preferred example, the AC coupling is an inductive coupling, and the coupling is effectively configured as an extra center tap of a high voltage transformer of a display device, such as a television device. This saves complete inductive coupling. The shadow-free masking and chasing elephant CRT electric 3 is different-the example is characterized in that the demodulator includes an AM detection circuit and a phase comparator, which provide the relevant electronic beam displacement and the relevant displacement direction of the center of the self-acting track, respectively. Information. This example can provide detailed information about the displacement, velocity, and heading of the individual separate electron beams. The invention also relates to a display device, such as a television device, including those defined in claims 1 to 9 of the patent The 5th image, the cathode ray tube circuit, wherein the cathode ray tube circuit includes a coupling device that is connected to a shadowless masking cathode ray tube, which obtains a signal of chase ^, the characteristic of this device is that the handle device includes a Modulator & demodulator circuit. Together with its additional advantages, the tracking circuit and display device of the present invention will now be described with reference to the accompanying drawings, in which similar components are indicated by the same reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a portion of a display device equipped with a shadowless mask 1 Figure and Figure 2 show that the tracing circuit includes a power supply for one of the display devices of Figure 1 and

V. Description of the invention (4)

Detailed drawing of the oscillating device E CRT I w ^ Figure 1 shows whether there is one or not, a cathode ray tube, hereinafter referred to as LKT 1, and the first display shows the pump odor 叩 ^ wh Shaped toilet pump, from the picture. Device D provides a tracking device in the form of a tracking circuit 2 that is connected to the tracking device? One] Self Secret CRT # Thunder Road 3. Tracking circuit 2 can be used to force the circuit 1 of the circuit 2 & control circuit f step * also add a tracking signal from the CRT 1 control circuit 3. [There are two control circuits 3 that can drive the CRT i 4. CRT 1 is a kind of cymbal, with a shadow cover. Sunshan —> In CRT i: the detector structure s can measure electrons; the position of the beam. When following the structure S :, description: fixed point, the chase step signal τ 1 is generated as 3 fixed point position correction for the tracking CRT control circuit 3. FIG. 1 further shows a diagram of a tracking circuit 2 including a modulation input tracking signal T i-a modulator 5 which is stacked at a very high voltage to obtain a modulation tracking image signal Tm and output a low-voltage modulation tracking One of the win signals Tml is the first AC coupling 6, and one of the demodulator 7 is obtained to obtain the basic band / unmodulated tracking signal To. The coupler is a modulator 5 and a demodulator 7 which are separated by an AC coupling 6 to a chirp oscillator 8 which provides a carrier frequency of the tracking signals Tm and Tm1. As shown, oscillators 8 to 5 are directly coupled and demodulator 7 is coupled 9 via a second AC coupling. If necessary, the oscillator 8 can be directly coupled to the demodulator 7 and the modulator 5 via the second AC. If time delay and phase delay are performed, no problem occurs.

FIG. 2 shows a detailed diagram of the tracking circuit 2 including a DC power supply 10, which is coupled to an oscilloscope 11 together with the oscillator. The converter 11 can convert the DC supply voltage to an AC voltage interrupted by a high-frequency vibrator signal, and this voltage also follows the (de) frequency modulation of the image signal. Rectangular converter output to the second AC 493195 V. Description of the invention (5) Engage 9. According to this situation, this engagement is an inductive engagement, but this light coupling is the first AC coupling, and it can also be a capacitor. It is sexually coupled in order to insulate the ground from the high potential on the secondary side of the coupling 9. The secondary side can be coupled to the rectifier 12 and a filter circuit 13 'to supply a DC power supply voltage to the demodulator 7. The oscillator signal can be obtained from the secondary side of the transformer coupling 9 and fed to the modulator 5 via an amplifier 14. The modulator 5 may also receive a modulation signal from the AC coupling 6 to generate one of the output tracking signals | signals To required by the control circuit 3. Several examples and variations are possible for those skilled in the art. Directly couple the oscillator 8 to the demodulator 7 as described above, and compare the example shown in Figs. 1 and 2 with a DC power supply voltage 俾 from the autotransport potential side of the power supply to the high potential side of the AC couplings 6 and 9. In this case, it is not necessary to change the well-known EHT transformer. The demodulator 7 may also include a well-known AM detection circuit and a phase comparator, which respectively provide information about the fixed position of the electronic beam and the direction of the displacement from the magnetic actuator center. But instead of using a sync detector. Instead of using a separate transformer, an additional tap on a high-voltage transformer includes a coupling 9, which is incorporated in current display devices such as television devices. Configurable modulator-modulator circuits 5, 7 for analog modulation, such as amplitude modulation (AM) cycle frequency (FM), phase modulation (PM), double sideband shoulder, system ~ (DSB), single sideband modulation (SSB) , Degraded sideband modulation (VSB), phase shift report (FSK), etc.

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Claims (1)

89125488% year, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month, month At the month, the sixth amendment, the scope of patent application 1. A f-ray tube circuit (2, 3) A tracking signal (TO) is obtained, which is characterized in that the tracking device includes a modulator-demodulator circuit (5, 7) with a modulator (5) for modulating an input provided by the cathode-ray tube Track 4 signals (T i) to obtain a modulated tracking # signal (Tm) and a demodulator (7) for demodulating the modulated tracking # signal to obtain a tracking # signal (Ding 0). Its special solution 2. If the patent application scope of the first pursuit of 4 cathode ray tube circuit sign is: the modulator connected to the shadowless cover of the cathode ray tube is modulated by a first AC coupling 3 For example, the pursuit of a cathode ray tube circuit in the scope of patent application item 1 is that the pursuit circuit includes a vibrator coupled to one of a modulator and a demodulator. -4. The cathodic ray tube circuit as claimed in item 3 of the patent, characterized in that the oscillator is connected to the modulator and is coupled to the demodulator via a second AC coupling. 5. The cathod ray tube circuit according to item 4 of the patent application, characterized in that the oscillator is coupled to a DC / AC converter, which must also be coupled to a DC power source and its converter output is coupled to Second AC coupling. 6. Cathode ray tube circuit according to item 1 of the scope of patent application, characterized in that the AC coupling is a capacitive, inductive, optical or acoustic coupling. 7. If the cathode ray tube circuit of item 6 in the patent application scope is characterized in that the AC coupling is an inductive coupling, it is configured as a display device O: \ 67 \ 67928-910403.ptc page 10 499 + 95- n / B correction 89125488, Cao Patent Fan, one of the high voltage transformers 8. If the scope of patent application is levied on: the configuration of the modulator, frequency modulation (FM), phase modulation sideband modulation (SSB), (FSK) and so on. 9. If the scope of patent application lies in: The demodulator includes information from the magnetic control center. 1 0. A display device, a polar tube circuit, wherein the coupling of the cathode ray tube is: the coupling device includes an external tap. The 5th item of the first item is a cathode ray tube circuit, and its special demodulator is analog modulation, such as amplitude modulation (AM) (PM), double sideband modulation (DSB), single 1 degraded sideband modulation (VSB), shift The phase-reporting cathode-ray tube circuit of item 8 of the report, which has a special AM detection circuit and a phase comparator, respectively, the electronic beam displacement and the direction of the relevant displacement, including the cathode-recovery cathode, such as the application of the first scope of the patent application. The ray tube circuit includes a tracking signal connected to the tracking device, which is characterized by a modulator and a demodulator circuit. (I O: \ 67 \ 67928-910403.ptc Page 11