CN2370513Y

CN2370513Y - Screen protector of image display terminal

Info

Publication number: CN2370513Y
Application number: CN 99204326
Authority: CN
Inventors: 陈伟越
Original assignee: Shenzhen City Nec Electronics Co Ltd
Current assignee: Shenzhen City Nec Electronics Co Ltd
Priority date: 1999-03-01
Filing date: 1999-03-01
Publication date: 2000-03-22
Anticipated expiration: 2009-03-01

Abstract

The utility model relates to a screen and circumference protector of an image display terminal apparatus, which is suitable for any image display terminal. The utility model comprises a cathode ray tube, and high voltage ground wires and a plastic casing at periphery of the cathode ray tube, etc. High conductive net cloth is appressed with proper positions in front of the surface of a viewing screen of the cathode ray tube by a metal frame which is connected with the ground wires; a metal foil is used for shielding high-pressure ground wires of a kinescope, and is connected with the ground wires; the interior of the plastic casing is sprayed with a layer of mixed electric conductive paint and metallic powder, and the conductive layer is connected with the ground wires. The utility model has the advantages of radiation prevention, visual obsession decrease, etc.

Description

The fluorescent screen protective device of image display terminal

The utility model relates to fluorescent screen and the peripheral protective device in a kind of image display terminal, and protective device especially of the present utility model goes for any image display terminal.

At present, general image display terminal (VDT) is if the perfect protective device of neither one, not only can't effectively weaken high light, reflected light, absorption and eliminate static charge rapidly, and low frequency radiation and high frequency radiation more can cause the wavy striped that influences vision/or spinoff such as Newton ring, have a strong impact on the visual effect of fluorescent screen.In recent years, such as information treatment facility, computer monitor, electronic game machine display, televisor ... wait relevant VDT equipment to increase sharply, and be widely used.Data shows that the cathode ray tube (CRT) surface among the VDT can produce high light, add the caused reflected light of external light, can cause that staff's eye fatigue, intraocular pressure increase headache ...., another even more serious problem is static charge and the low frequency radiation that VDT sends, and being considered to has potential nocuity to health.In fact, reported many cases in many scientists and doctor's the research report, had in the international scientific meeting at the display device worker suitable scientist and doctors to report specially all to show in the research of many relevant VDT the CRT video screen launched static charge to attract the dust of the bacterium of oppositely charged and stimulus etc. or pollutant to the fluorescent screen and quicken because of repelling each other to bombard easily with 1987 with first boundary that held in 1989 and second boundary especially to the operator with the dust or the pollutant of the bacterium of identical charges or stimulus etc.In addition, the non-ionising radiation that launch the fluorescent screen has been argued for many years, though report in some report, the electron irradiation that CRT sends the fluorescent screen is far below the standard that can cause that the operator is hurt, yet, this low frequency radiation is the fact that exists really, even some old-fashioned or relatively poor VDT, and its radiant quantity has surpassed the standard (as FDA or DHHS standard) of permission.Though now have among the VDT of manufacturer production so-called " anti-static ", but it just plates or tumbles in the conductive film of layer of transparent on the CRT surface, because of its resistance value is still very high, so conductive effect is perfect inadequately, and, phenomenons such as emission and scattering have been increased on the contrary because this film is transparent.Now, because kind and the pattern of VDT have been too much really, especially color CRT and the cloudy cover that covers thereof mostly are irony or iron-nickel alloy greatly, when VDT in use, the moon cover cover the hole can because the heating and expand, cause aberration or wavy striped, Newton ring etc. sometimes.The inventor finds many problems because the congenital problem of line design and CRT forms in experiment, the many patents (safety goggles of on the market external hanging type, eye protecting net) of these problems before being again etc. can not solve fully; And many problems still occur in after the above-mentioned patented claim, can only overcome high light and reflected light etc. as safety goggles, after using, find, because dust easily is adsorbed and there have part to stick to be online, causes the vision puzzlement easily, more can produce spinoffs such as wavy striped and Newton ring; Eye protecting net just weakens fluorescent screen forward part high light, reflected light and weakens static charge, low frequency radiation etc.And the said goods all can not shield the electromagnetic wave that VDT is distributed behind.

The purpose of this utility model provides a kind of fluorescent screen integrated protection device that is used for the image display terminal, with solve existing technical with use the problems that exist.

The utility model is achieved in that the utility model comprises high pressure ground wire around cathode-ray tube (CRT) and the teletron thereof, plastic casing etc., it is characterized in that metal frame is close to the high-conductivity screen cloth on the appropriate location of putting before the cathode-ray tube (CRT) significant screen surface, metal frame is connected with ground path; Be connected by metal forming shielding teletron high pressure ground wire and with ground wire; Plastic housing internal spray one deck electroconductive paints is mixed metal powder, and this conductive layer is connected with ground path.Therefore high light that VDT produced and reflected light are stopped by the preferred structure of high conduction conduction network cloth and suitably weaken, can adapt to human vision.Static charge that VDT launched and low frequency radiation, high frequency radiation will be absorbed by the high conductivity screen cloth and by earthing device, eliminate rapidly.Static charge and low frequency radiation that VDT is launched inside, high frequency radiation is eliminated rapidly by the most of absorption of high-conductivity metal coating shell and by earthing device.

The utility model compared with prior art has the radiation of preventing, reduces advantages such as vision puzzlement.

Description of drawings of the present utility model is as follows:

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is the high conduction network cloth opening form of a utility model synoptic diagram.

Fig. 3 is a transmittance synoptic diagram of the present utility model.

Fig. 4 is the graph of a relation between the utility model mesh wire diameter and resolution and some distance.

Below in conjunction with accompanying drawing, the utility model is done further concrete the introduction.As shown in Figure 1, the utility model includes frame, high conductivity screen cloth 1 and suitable ground path, and be close on the appropriate location that is placed on before the CRT surface with suitable mode, with high-conductive metal paper tinsel 2 shielding high pressure ground wire and ground connection, mix metal powder 3 with plastic housing internal spray and ground connection with electroconductive paints.The feature of high conductivity screen cloth 1 wherein has following feature according to the character of CRT:

(A) resistance: R＜10 ⁵Europe;

(B) transmittance: 1/3＜T＜2/3;

(C) mesh wire diameter: D＜MIN (D1, D2)

D1=V D x25.4x0.8/R V x0.16 wherein

Or D1=V D x25.4x0.6/R H x0.16

D2＝PA3-QA2+RA-S

P＝1.342+0.002

Q＝2.032+0.002

R＝1.011+0.002

S＝0.116+0.002

Wherein size (representing with diagonal line lnch usually) is watched in the VD representative;

RH represents the horizontal scanning line number;

RV represents the vertical scan line number;

A representative point spacing (Dot, Pitch);

(D) as shown in Figure 2, high conduction network cloth 1 opening form of the present utility model has circle, ellipse, polygon, square etc., or other variant shape;

(E) angle of twine and CRT horizontal direction: 0＜45 °.

In VDT inside with metal forming with high pressure ground shield and ground connection around the kinescope, and the high-conductive metal lacquer is sprayed on the inside of plastic casing.

The utility model is that the characteristics that it had are to effective improvement of fluorescent screen protection:

1, high light that VDT produced and reflected light are stopped by the preferred structure of black conductive screen cloth and suitably weaken, and can adapt to human vision.

2, the contrast of VDT suitably increases, to lower the burden of eyes.

3, static charge that VDT launched and low frequency radiation, high frequency radiation will be absorbed by high conductivity screen cloth 1 and by earthing device, eliminate rapidly.

4, with special black conductive screen cloth 1 structure organization, prevent line shape striped and/spinoffs such as Newton ring, to avoid vision puzzlement.

5, avoid producing aberration and abnormal color because of the ground magnetic influence.

6, static charge and the low frequency radiation launched of VDT inside, high frequency radiation are absorbed and by earthing device, eliminate rapidly by high-conductivity metal coating 3 shells are most of.

Common VDT display speed is mostly in 30 pictures/second, some high-res in addition surpass 70 pictures/second, fast more or color is many more as display speed, then VDT static charge of launching and low frequency radiation are just high more, so must need a preferable conduction network cloth 1 could realize absorbing preferably and conducting effect, done a series of experiment test through the inventor, be less than or equal to 10 if find the resistance of conduction network cloth 1 ⁵During Europe, then absorb with the effect of conduction just quite satisfied.Have and consider human visual effect, through experimental test and analysis, it is best being situated between between 1/3 and 2/3 as transmittance.The computing method of transmittance shown in Figure 3 are T=A/X.Y, and wherein A is an aperture area, and X, Y are respectively opening portion and add length behind the mesh wire diameter and wide, and the D shown in the figure is a mesh wire diameter.Include high light and catoptrical combination when what operator's note that the surface, fluorescent screen the time sees, if transmittance is lower than 1/3 or be higher than 2/3 o'clock poor effect.Opposite, if transmittance is lower than between the above-mentioned numerical value, then the vitality of eyes will surpass more than the twice when not using the utility model.Prior problem is spinoffs such as wavy striped and Newton ring, especially on colored VDT, relation as above-mentioned phosphor dot and cathode shield and line design all can be found the defective that some are slight, especially easier discovery when high of healing of a lot of at color, sharpness is not clearly described or the indication disposal route in the former technology.The utility model is when design, experiment, with avoiding these spinoffs fully and producing comfortable vision is condition precedent, show situation defective inborn with reference to eyes resolution characteristic and various VDT with it, experiment condition with strictness, find out the line footpath of CRT and screen cloth 1 and the relation of opening, as shown in Figure 4.

Claims

1, a kind of fluorescent screen protective device of image display terminal, comprise high pressure ground wire around cathode-ray tube (CRT) and the teletron thereof, plastic casing etc., it is characterized in that metal frame is close to the high-conductivity screen cloth on the appropriate location of putting before the cathode-ray tube (CRT) significant screen surface, metal frame is connected with ground path; Be connected by metal forming shielding teletron high pressure ground wire and with ground wire; Plastic housing internal spray one deck electroconductive paints is mixed metal powder, and this conductive layer is connected with ground path.

2, the fluorescent screen protective device of image display terminal according to claim 1 is characterized in that metal frame is close to the high-conductivity screen cloth on the appropriate location of putting before the cathode-ray tube (CRT) significant screen surface, and high conductivity screen cloth opening form is a square.

3, the fluorescent screen protective device of image display terminal according to claim 1 is characterized in that metal frame is close to the high-conductivity screen cloth on the appropriate location of putting before the cathode-ray tube (CRT) significant screen surface, and high conductivity screen cloth opening form is a garden shape.

4, the fluorescent screen protective device of image display terminal according to claim 1 is characterized in that metal frame is close to the high-conductivity screen cloth on the appropriate location of putting before the cathode-ray tube (CRT) significant screen surface, and high conductivity screen cloth opening form is oval.

5, according to the fluorescent screen protective device of claim 1 or 2 or 3 or 4 described image display terminals, the resistance R that it is characterized in that the high-conductivity screen cloth is less than 10 ⁵Europe, twine and cathod-ray tube square to angle less than 45 °.