CN2349646Y - Potentiometer without black point focus on CRT screen - Google Patents
Potentiometer without black point focus on CRT screen Download PDFInfo
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- CN2349646Y CN2349646Y CN 98218125 CN98218125U CN2349646Y CN 2349646 Y CN2349646 Y CN 2349646Y CN 98218125 CN98218125 CN 98218125 CN 98218125 U CN98218125 U CN 98218125U CN 2349646 Y CN2349646 Y CN 2349646Y
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- cathode
- ray tube
- focus
- tube display
- potentiometer
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Abstract
The utility model relates to a potentiometer without black point focusing on a CRT screen, which is characterized in that the input voltage a screen grid potential controller for the potentiometer is from a special external power supply, and the circuit of the screen grid potential controller and the circuit of a focus potentiometer are arranged on one basal plate or different basal plates in one shell. The voltage value of the screen grid potential controller disappears as soon as a CRT display is closed. The cathode current of the CRT display quickly disappears, so black points resulted from residual electronic beams can be prevented from being generated on the display panel of the CRT display. When the outlet voltage of the screen grid potential controller is adjusted in order to adjust the brightness of the CRT display, the output potential of the focus potentiometer is not influenced to ensure the displaying clearness.
Description
The utility model is a kind of improvement of focus variable rheostat, especially refer to a kind of no stain focus variable rheostat, the input voltage of a set focus variable rheostat and a screen grid potential controller is respectively from two power supplys independently in this potentiometer, and the circuit of this screen grid potential controller and this focus variable rheostat is on the same or different substrate of being located in the same housing, the magnitude of voltage that makes the screen grid potential controller is after cathode-ray tube display is shut down, can disappear at once, and then the anode current of cathode-ray tube display is also rapidly disappeared, effectively to avoid the residual electrons bundle on the display pannel of this cathode ray tube, to produce stain, and when this cathode-ray tube display being carried out the brightness adjustment, also unlikely definition to this cathode-ray tube display causes negative effect.
Conventional cathode ray tube display (CRT DISPLAY, abbreviation CRT) developing method, it mainly is the electron beam that utilizes its high hot cathode to produce, and on the fluorescent layer that is coated with of the panel inboard that periodically is projected to this cathode-ray tube display, make this fluorescent layer form picture because of sensitization, in general cathode-ray tube display, the fluorescent layer surface of this this display pannel of cathode distance is about 350 millimeters, and must be with the high voltage of about 25KV, the electron beam that order is produced quickens and obtains enough energy.Generally speaking, beam diameter that this negative electrode produces is former to be about 0.2 millimeter, but because each electronics in the electron beam has negative electrical charge, so when electron beam arrives the fluorescent layer surface, because of producing mutual exclusion between each electronics, and make beam diameter become about 1 millimeter, and cause image fog shown on the fluorescent layer, make the definition of image reduce.
At this disappearance, the manufacturer of conventional cathode ray tube display is before electron beam arrives the fluorescent layer surface, utilize an electron lens, the electron beam that spreads is focused on formation one satisfactory electron beam, and make its focus just can converge on the fluorescent layer surface.Press, be equipped with an electron gun in the conventional cathode ray tube display, this electron gun mainly is made up of institutes such as negative electrode, the brilliance control utmost point (or claiming screen grid), anode, burnt poly-electrode and anodes, and the main focussing force of electron lens is to occur between the poly-electrode of this Jiao and this anode, focus variable rheostat then is in order to provide this Jiao to gather the required electric energy of electrode normal operation, to make electron lens can effectively solve the fuzzy shortcoming of video picture on electron beam diffusion and the fluorescent layer.Usually, on the conventional cathode ray tube display,,, be called monofocal potentiometer (being called for short SF) to reach this purpose by installing one focus variable rheostat; In addition, the cathode-ray tube display of having relatively high expectations for image definition, as: high-res and/or large-sized cathode-ray tube display, then must utilize two to focus on the focusing that potentiometer is realized horizontal sweep and vertical scanning direction respectively, be called double focusing potentiometer (being called for short DAF or FSVR), consult shown in Figure 1.
See also shown in Figure 1 again, this focus variable rheostat is to see through the high voltage that contact 1 input is produced by the high-pressure generator institute generator in the cathode-ray tube display, see through again and adjust variable resistor R2 and R8, see through the magnitude of voltage that contact 2 exports the poly-electrode of this Jiao to adjust this two focusing potentiometer F1 and F2, provide this Jiao to gather the required electric energy of electrode normal operation, the electron beam of order diffusion just can focus on the fluorescent layer surface.In traditional focus variable rheostat, because its contact 6 is a ground connection, so related resistors (equivalent resistance that contact 1 and contact are 6 that is set in this focus variable rheostat, about 500M Ω), also can be used as a discharge circuit, after this cathode-ray tube display is shut down, can carry out discharge process to the high-voltage capacitance of this cathode-ray tube display.
In addition, the conventional cathode ray tube display makes electron beam suitably be focused on the function on fluorescent layer surface except that possessing, also should possess the function of adjusting brightness, traditional practice, mainly be (to be called Screen Grid Voltage Regulator by adding a screen grid potential controller, be called for short SGVR), to adjust the control voltage of this screen grid potential controller, and the purpose that realization brightness is adjusted, consulting shown in Figure 2ly, is the equivalent electric circuit between this screen grid potential controller and cathode-ray tube display.
Consult again shown in Figure 2, R in the equivalent electric circuit of this cathode-ray tube display
iRepresent anode current i
HvThe equivalent resistance of being flowed through:
R
i=HV/i
hv25KV/300μA=83MΩ
Wherein HV representative is produced and is exported to the high voltage of anode by high-pressure generator, generally is about 25KV, when the unglazed territory of screen panel of this cathode-ray tube display or when being shut down, and this R
iValue is open-circuit condition because of circuit, so the resistance infinity.
This screen grid potential controller can be a part independently, see also shown in Figure 2, this screen grid potential controller can see through adjusts variable resistor R4, see through the magnitude of voltage that contact 3 exports this screen grid to adjust this controller, make and use the screen brightness of adjusting this cathode-ray tube display, but based on economic factor, this screen grid potential controller generally all is designed to one with this focus variable rheostat, and become the some of circuit in the traditional focus potentiometer, consult shown in Figure 3, and make these circuit layouts on same circuit substrate, consult shown in Figure 4.
In practical application, consult shown in Figure 4, this traditional focus potentiometer generally all be with this cathode-ray tube display on high-pressure generator be assembled into one, consult shown in Figure 5, this traditional focus variable rheostat is provided with two and focuses on current potential adjustment button B1, B2 and a screen grid potential control knob B3, and control sees through the potential value that contact 2 and 3 exports focusing electrode and screen grid to respectively.Because this focus variable rheostat sees through the voltage of contact 1 input up to 25KV, so in design, for limiting its resistive loss below 2watts, the equivalent resistance R of its voltage input contact 1 and earth terminal 6
1-6, consult shown in Figure 6, between 500M Ω-600M Ω.
See also shown in Figure 3, anode in this cathode-ray tube display mainly is that the coating by conduction is coated on that an ancient piece of jade, round, flat and with a hole in its centre is constituted in this cathode-ray tube display, so this cathode-ray tube display is a high-voltage capacitor C and variable-resistance combination on electric, the about 1500PF of C value wherein, but in the design ripple that reduces because of high voltage produced, general all again and an electric capacity at this high-voltage capacitor C, make its total capacitance C.Approximate 6000PF, this total capacitance C.During switch, will store the high voltage electricity of about 25KV, and after shutdown, make this high voltage electricity through equivalent resistance R
1-6Discharge, its magnitude of voltage is successively decreased according to following formula;
V=Hvoe
-t/3
Yet, after cathode-ray tube display is shut down, though level and vertical deflection scanning yoke (DeflectionYoke, be called for short DY) stopped to electron beam sweep work partially because the total capacitance C of cathode-ray tube display.Still accumulate high voltage HV is arranged., and negative electrode still has suitable heat energy, causes negative electrode in a period of time, will continue to produce electron beam, and making these electron beams continue to be projected to the center position on the fluorescent layer surface of cathode-ray tube display, it continues to produce time of electron beam, will look this total capacitance C.Current potential size and decide.This total capacitance C.Current potential V change, be according to V=HV
0e
-t/3And decide (wherein T is the second number of starting at after cathode-ray tube display is shut down), so by this total capacitance C.Equivalent electric circuit see it, consult shown in Figure 6ly, as long as the current potential of this screen grid potential controller is enough high, the central point on the fluorescent layer surface of this cathode-ray tube display will continue to be throwed by electron beam.So, the central point on this fluorescent layer surface is because the result who is throwed by electron beam for a long time, the central point on this fluorescent layer surface of military order takes place aging, produce a stain (SPOT), this stain easily causes the user that drawing shown on this display is misread, and the generation of this stain is the negative effect that this screen grid potential controller is caused.
In addition, because the base plate line between this focus variable rheostat and screen grid potential controller is to be series connection, so utilizing, the user adjusts the screen grid potential control knob, when adjusting at the display brightness of this cathode-ray tube display, the output potential of this focus variable rheostat also will be subjected to modulation, therefore, the effect of this kind intermodulation (CROSS TALK) also causes negative to the effect that focuses on and influences.
Because the aforementioned conventional focus variable rheostat utilization circuit that institute's cloth is built on a substrate, focusing is provided, brightness adjustment and shutdown back high voltage electricity function such as release, only, but cause on the central point on the fluorescent layer surface of cathode-ray tube display and produce stain, and the focusing effect of focus variable rheostat is caused negative shortcomings such as influence because of the intermodulation effect, the creator is that study and composition goes out a kind of no stain focus variable rheostat, utilize this focus variable rheostat effectively to improve shortcomings such as this stain and intermodulation effect, required collating time and the step on the assembling processing procedure with effective shortening and simplification cathode-ray tube display, and significantly promote the definition of image, and avoid on cathode-ray tube display, producing the phenomenon of stain.
Promptly, shortcoming at prior art, the purpose of this utility model, be a focus variable rheostat set in this potentiometer and the input voltage of a screen grid potential controller, respectively from two power supplys independently, and the circuit of this screen grid potential controller and this focus variable rheostat is on the same or different substrate of being located in the same housing, the magnitude of voltage that makes this screen grid potential controller is after cathode-ray tube display is shut down, can disappear at once, and then make the anode current of cathode-ray tube display also rapidly disappear, effectively to avoid this cathode ray tube to be produced the residual electrons bundle, cause continues to be projected on this cathode-ray tube display face plate center position, and forms stain at display floater.
Another purpose of the present utility model, be when this cathode-ray tube display being carried out the brightness adjustment, reason is not adjusted the output voltage of this screen grid potential controller, and influence the output voltage of this focus variable rheostat to focusing electrode, so in the time of can guaranteeing to adjust brightness, this cathode-ray tube display be still kept normal image definition.
Above-mentioned purpose of the present utility model can realize by following mode: a kind of no stain focus variable rheostat is characterized in that comprising: a housing, this housing are provided with a plurality of adjustment buttons; Two focus on potentiometer, be on the substrate of being located in this housing, this two focusing potentiometer is to be connected to a power supply, to import required high voltage, and through adjusting two corresponding on this housing adjustment buttons, two focus on potentiometer institute's variable resistor of setting respectively to adjust this, and then adjust this and two focus on the magnitude of voltage that potentiometer exports a burnt poly-electrode of this cathode-ray tube display to, make the electron beam in this cathode-ray tube display just can focus on the fluorescent layer surface of this cathode-ray tube display, this two focuses on potentiometer and is connected with an earth terminal; One screen grid potential controller, be on this substrate or another substrate of being located in this housing, this screen grid potential controller is to be connected to another power supply, with the input required voltage, see through again and adjust an adjustment button corresponding on this housing, to adjust set variable resistor on this screen grid potential controller, and then adjust the magnitude of voltage that this screen grid potential controller exports a screen grid of this cathode-ray tube display to, changing the screen brightness of this cathode-ray tube display, this grid potential controller also is connected with an earth terminal.This two focusing potentiometer can be a focus variable rheostat, this focus variable rheostat is to be connected to a power supply, to import required high voltage, and through an adjustment button corresponding on this housing, to adjust a variable resistor set on this focus variable rheostat, and then adjust the magnitude of voltage that this focus variable rheostat exports a burnt poly-electrode of this cathode-ray tube display to, make the electron beam in this cathode-ray tube display just can focus on the fluorescent layer surface of this cathode-ray tube display, this focus variable rheostat also is connected with an earth terminal.
Description of drawings:
Fig. 1 is the circuit diagram of traditional double focus variable rheostat;
Fig. 2 is the schematic equivalent circuit between screen grid potential controller and cathode-ray tube display;
Fig. 3 is the schematic equivalent circuit between traditional double focus variable rheostat and cathode-ray tube display;
Fig. 4 is the circuit substrate schematic diagram of traditional double focus variable rheostat;
Fig. 5 is the schematic appearance of high-pressure generator and double focusing potentiometer on the conventional cathode ray tube display;
Fig. 6 is the simple equivalent circuit schematic diagram between traditional double focus variable rheostat and cathode-ray tube display;
Fig. 7 is that the utility model does not have the schematic equivalent circuit between stain focus variable rheostat and cathode-ray tube display;
Fig. 8 is the circuit substrate schematic diagram of no stain focus variable rheostat of the present utility model.
In no stain focus variable rheostat of the present utility model, be to be most preferred embodiment with a pair of focus variable rheostat, be described as follows, consult shown in Figure 7, this focus variable rheostat is on the substrate of being located in the housing, and see through the high voltage that contact 1 input is produced by the high-pressure generator in the cathode-ray tube display, and its electric energy is sent to two circuit that focus on potentiometer F1 and F2 respectively, see through two outer adjustment buttons of housing again, adjust this two variable resistor R2 and R8 that focuses on the circuit of potentiometer F1 and F2, see through the magnitude of voltage that contact 2 exports the poly-electrode of this Jiao to adjust this two focusing potentiometer F1 and F2, the burnt poly-required electric energy of electrode normal operation in the cathode-ray tube display is provided, the electron beam of order diffusion just can focus on the fluorescent layer surface, this two focusing potentiometer F1 and F2 see through contact 6 again and are connected with earth terminal, as shown in Figure 7 in the circuit of this focus variable rheostat, R0, R1, R2, R3, R6, R7, R8, R9 and figure R10 are that this circuit is according to the designed load of actual demand.
In addition, be provided with a screen grid potential controller independently in the circuit of this focus variable rheostat of the utility model, see also shown in Figure 7, the circuit of this screen grid potential controller and this focus variable rheostat is on the same or different substrate of being located in the same housing, this grid potential controller is to see through the voltage that contact 5 is imported by external power supply provided, this screen grid potential controller can see through another outer adjustment button of housing, adjust variable resistor R4, see through the magnitude of voltage that contact 3 exports this screen grid to adjust this controller, use the screen brightness of adjusting this cathode-ray tube display, this grid potential controller also sees through contact 6 and is connected with earth terminal.
Because, in the utility model, the required voltage of this grid potential controller normal operation, be specially by contact 5 inputs, but not from this high-pressure generator, so after cathode-ray tube display is shut down, this magnitude of voltage will disappear at once, and the equivalent resistance R that flows through in the equivalent electric circuit of this cathode-ray tube display
iAnode current i
HvAlso disappear at once, and unlikely this cathode-ray tube display that makes produces the residual electrons bundle, can effectively avoid continuing to be projected to the stain that this cathode-ray tube display center is produced because of electron beam.
In addition, because the input power supply of this grid potential controller of the present utility model is the supply independent with this focus variable rheostat, so when the user adjusts at the display brightness of this cathode-ray tube display, the output potential of this focus variable rheostat is affected unlikely, so can guarantee the focusing effect of this focus variable rheostat.Consult shown in Figure 8, promptly according to the circuit substrate schematic diagram of the no stain focus variable rheostat of the utility model design.
The above; it only is a preferred embodiment of the present utility model; only; the interest field that the utility model is advocated is not limited thereto, and presses all this skill personages that is familiar with; according to the disclosed technology contents of the utility model; can think easily and equivalence change, as the utility model being applied to the monofocal potentiometer, all should belonging to do not break away from protection category of the present utility model.
Claims (2)
1, a kind of no stain focus variable rheostat is characterized in that comprising:
One housing, this housing are provided with a plurality of adjustment buttons;
Two focus on potentiometer, be on the substrate of being located in this housing, this two focusing potentiometer is to be connected to a power supply, to import required high voltage, and through adjusting two corresponding on this housing adjustment buttons, two focus on potentiometer institute's variable resistor of setting respectively to adjust this, and then adjust this and two focus on the magnitude of voltage that potentiometer exports a burnt poly-electrode of this cathode-ray tube display to, make the electron beam in this cathode-ray tube display just can focus on the fluorescent layer surface of this cathode-ray tube display, this two focuses on potentiometer and is connected with an earth terminal;
One screen grid potential controller, be on this substrate or another substrate of being located in this housing, this screen grid potential controller is to be connected to another power supply, with the input required voltage, see through again and adjust an adjustment button corresponding on this housing, to adjust set variable resistor on this screen grid potential controller, and then adjust the magnitude of voltage that this screen grid potential controller exports a screen grid of this cathode-ray tube display to, changing the screen brightness of this cathode-ray tube display, this grid potential controller also is connected with an earth terminal.
2, a kind of no stain focus variable rheostat as claimed in claim, it is characterized in that: this two focusing potentiometer can be a focus variable rheostat, this focus variable rheostat is to be connected to a power supply, to import required high voltage, and through an adjustment button corresponding on this housing, to adjust a variable resistor set on this focus variable rheostat, and then adjust the magnitude of voltage that this focus variable rheostat exports a burnt poly-electrode of this cathode-ray tube display to, make the electron beam in this cathode-ray tube display just can focus on the fluorescent layer surface of this cathode-ray tube display, this focus variable rheostat also is connected with an earth terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 98218125 CN2349646Y (en) | 1998-08-03 | 1998-08-03 | Potentiometer without black point focus on CRT screen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 98218125 CN2349646Y (en) | 1998-08-03 | 1998-08-03 | Potentiometer without black point focus on CRT screen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2349646Y true CN2349646Y (en) | 1999-11-17 |
Family
ID=33970514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 98218125 Expired - Fee Related CN2349646Y (en) | 1998-08-03 | 1998-08-03 | Potentiometer without black point focus on CRT screen |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2349646Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014201790A1 (en) * | 2013-06-21 | 2014-12-24 | 合肥京东方光电科技有限公司 | Voltage regulation circuit of common electrode and display device |
-
1998
- 1998-08-03 CN CN 98218125 patent/CN2349646Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014201790A1 (en) * | 2013-06-21 | 2014-12-24 | 合肥京东方光电科技有限公司 | Voltage regulation circuit of common electrode and display device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |