1. An ultraviolet alignment device, comprising:

the first illumination unit and the second illumination unit are oppositely arranged; and

the supporting unit is arranged between the first illumination unit and the second illumination unit, is close to the second illumination unit, and is used for supporting the liquid crystal panel;

the first illumination unit and the second illumination unit carry out ultraviolet illumination alignment on the liquid crystal panel, and the average value of the pretilt angles of the liquid crystal molecules close to the first illumination unit is smaller than the average value of the pretilt angles of the liquid crystal molecules close to the second illumination unit.

2. The UV alignment device according to claim 1, wherein the difference between the average value of the pretilt angles of the liquid crystal molecules near the second light unit and the average value of the pretilt angles of the liquid crystal molecules near the first light unit is 1-4 °.

3. The ultraviolet alignment device of claim 1, wherein the support unit comprises a support table and a support frame disposed on an upper surface of the support table; the second illumination unit is arranged in the support frame, and the first illumination unit is arranged above the support frame; the second illumination unit comprises at least two second UV light sources which are arranged at intervals.

4. The ultraviolet alignment device according to claim 1, wherein at least one temperature control member is disposed outside the second illumination unit.

5. The ultraviolet alignment device of claim 3, wherein the first illumination unit comprises two or more first UV light sources arranged at intervals, and the first UV light sources are metal halide lamps, fluorescent lamps or LED lamps.

6. The ultraviolet alignment device of claim 3, wherein the support frame comprises at least two support rods arranged at intervals; the second UV light sources are arranged between the supporting rods at intervals.

7. The ultraviolet alignment device of claim 3, wherein the support frame comprises at least two support rods arranged at intervals and a light-transmitting plate arranged at the upper ends of the support rods, and the second UV light sources are arranged between the support rods at intervals.

8. The ultraviolet alignment device of claim 3, wherein the second UV light source is a metal halide lamp, a fluorescent lamp, or an LED lamp.

9. An ultraviolet alignment method is characterized by comprising the following steps:

s101, providing the ultraviolet alignment device as claimed in claim 1;

s102, arranging a liquid crystal panel on the upper surface of a support frame, and applying alignment voltage to an upper substrate and a lower substrate of the liquid crystal panel;

s103, after the alignment voltage is applied, starting a second illumination unit to perform ultraviolet illumination alignment on the liquid crystal panel;

and S104, starting a first illumination unit, and simultaneously carrying out ultraviolet illumination alignment on the liquid crystal panel by the first illumination unit and the second illumination unit.

10. The UV alignment method of claim 9, wherein during UV alignment, the temperature control member is turned on to control the ambient temperature of the liquid crystal panel to 30-60 ℃.

Background

In the TFT-LCD (thin film transistor liquid crystal display) technology, PS-VA (polymer stabilized vertical alignment) is currently adopted by more and more TV products due to its characteristics of high contrast and fast response time.

The process for forming the pre-tilt angle of the liquid crystal molecules in the PS-VA technology is one-time ultraviolet light alignment, the liquid crystal molecules are tilted by applying voltage to a substrate, and then ultraviolet light is irradiated to enable the reactive monomers in the liquid crystal to generate polymerization reaction, so that the pre-tilt angle is formed. The ultraviolet alignment is realized by an alignment ultraviolet irradiator, the core of which is an ultraviolet light source, and in the alignment ultraviolet irradiator 100a currently produced in mass production, as shown in fig. 1, a liquid crystal panel 200 is arranged on a carrier 110a, an ultraviolet light source 120a is arranged above the liquid crystal panel 200, and a light chopper is arranged between the ultraviolet light source 120a and the liquid crystal panel 200.

In the process of bending the liquid crystal panel 200 subjected to ultraviolet alignment by the conventional alignment ultraviolet irradiation machine 100a, referring to fig. 3b, the liquid crystal molecules 231 at the boundary of two adjacent domains 241 are crossed and "bridged" to cause dark fringes on the pixel electrode 240, and further cause a problem of dark clusters on the curved display area on the surface of the liquid crystal panel 200 in a macroscopic view.

Disclosure of Invention

The invention aims to solve the problem that dark clusters appear in a curved surface area after the traditional liquid crystal display panel is bent.

In order to achieve the above object, the present invention provides an ultraviolet alignment apparatus, including: the first illumination unit and the second illumination unit are oppositely arranged; the supporting unit is arranged between the first illumination unit and the second illumination unit, is close to the second illumination unit, and is used for supporting the liquid crystal panel; the first illumination unit and the second illumination unit carry out ultraviolet illumination alignment on the liquid crystal panel, and the average value of the pretilt angles of the liquid crystal molecules close to the first illumination unit is smaller than the average value of the pretilt angles of the liquid crystal molecules close to the second illumination unit.

Optionally, a difference between an average value of the pretilt angles of the liquid crystal molecules close to the second light irradiation unit and an average value of the pretilt angles of the liquid crystal molecules close to the first light irradiation unit is 1 to 4 °.

Optionally, the supporting unit includes a supporting table and a supporting frame disposed on an upper surface of the supporting table; the second illumination unit is arranged in the support frame, and the first illumination unit is arranged above the support frame; the second illumination unit comprises at least two second UV light sources which are arranged at intervals.

Optionally, at least one temperature control member is disposed outside the second illumination unit.

Optionally, the first illumination unit includes two or more first UV light sources arranged at intervals, and the first UV light sources are metal halide lamps, fluorescent lamps or LED lamps.

Optionally, the support frame includes at least two support rods arranged at intervals; the second UV light sources are arranged between the supporting rods at intervals.

Optionally, the support frame includes that at least two intervals are arranged branch and set up in the light-passing board of branch upper end, second UV light source interval arrange in between the branch.

Optionally, the second UV light source is a metal halide lamp, a fluorescent lamp or an LED lamp.

In order to achieve the above object, the present invention further provides an ultraviolet alignment method, comprising the following steps:

s101, providing the ultraviolet alignment device;

s102, arranging a liquid crystal panel on the upper surface of a support frame, and applying alignment voltage to an upper substrate and a lower substrate of the liquid crystal panel;

s103, after the alignment voltage is applied, starting a second illumination unit to perform ultraviolet illumination alignment on the liquid crystal panel;

and S104, starting a first illumination unit, and simultaneously carrying out ultraviolet illumination alignment on the liquid crystal panel by the first illumination unit and the second illumination unit.

Optionally, in the ultraviolet irradiation alignment process, the temperature control member is started to control the ambient temperature of the liquid crystal panel to be 30-60 ℃.

The ultraviolet alignment device and the alignment method have the beneficial effects that the first illumination unit and the second illumination unit which are oppositely arranged are adopted to carry out ultraviolet illumination alignment on the liquid crystal panel, and the first illumination unit and the second illumination unit are matched to form double-side ultraviolet illumination, so that the average value of the pretilt angles of the liquid crystal molecules close to the first illumination unit is reduced, the average value of the pretilt angles of the liquid crystal molecules close to the second illumination unit is increased, the difference of the pretilt angles of the liquid crystal molecules in the liquid crystal layer of the liquid crystal panel is realized, the dark cluster problem of curved surface display of the liquid crystal panel after the liquid crystal panel is bent is effectively improved, and the image quality of the liquid crystal display panel is improved.

Drawings

The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.

FIG. 1 is a schematic view of an assembly structure of a conventional alignment UV irradiator and a liquid crystal panel;

FIG. 2 is a schematic diagram of a pixel electrode structure;

FIG. 3a is a schematic diagram showing the arrangement of liquid crystal molecules at the boundary between two adjacent domains in the planar region of the liquid crystal panel;

FIG. 3b is a schematic diagram showing the arrangement of liquid crystal molecules at the boundary between two adjacent domains in the curved surface region of the liquid crystal panel;

FIG. 4 is a schematic structural diagram of an ultraviolet alignment apparatus in an exemplary embodiment of the invention;

fig. 5 is a schematic structural diagram of an ultraviolet alignment device in another exemplary embodiment of the present invention;

fig. 6 is a schematic structural diagram of an ultraviolet alignment device in a further exemplary embodiment of the present invention;

FIG. 7 is a schematic view of an assembly of an UV alignment device and a liquid crystal panel according to an exemplary embodiment of the invention;

FIG. 8 is a schematic view of an assembly of an UV alignment device and a liquid crystal panel according to another exemplary embodiment of the invention;

FIG. 9 is a schematic view of an assembly of an ultraviolet alignment device and a liquid crystal panel according to still another embodiment of the present invention;

FIG. 10 is a flow chart of a UV alignment method used in an exemplary embodiment of the invention;

fig. 11 is a schematic layout diagram of liquid crystal molecules at a boundary between two adjacent domains in a curved surface region of a liquid crystal panel after ultraviolet light alignment is performed by using the ultraviolet alignment device provided in the embodiment of the present invention.

The parts in the figure are numbered as follows:

100. the device comprises an ultraviolet alignment device, 110, a first illumination unit, 111, a first UV light source, 120, a second illumination unit, 121, a second UV light source, 130, a supporting unit, 131, a supporting table, 132, a supporting frame, 132a, a supporting rod, 132b, a supporting rod, 132c, a light-transmitting plate, 140, a temperature control member, 150 and a light chopper;

200. a liquid crystal panel, 210, an upper substrate, 220, a lower substrate, 230, a liquid crystal layer, 230a, an upper segment, 230b, a middle segment, 230c, a lower segment, 231, liquid crystal molecules, 240, a pixel electrode, 241, and domains;

100a, an alignment ultraviolet ray irradiation machine 110a, a stage 120a and an ultraviolet light source.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The ultraviolet alignment device is characterized in that a second illumination unit is additionally arranged below the liquid crystal panel, in the liquid crystal alignment process, the ultraviolet illumination of the second illumination unit is combined with the ultraviolet illumination of the first illumination unit, so that the average value of the pretilt angles of the liquid crystal molecules close to the lower substrate in the liquid crystal layer of the liquid crystal panel is larger than the average value of the pretilt angles of the liquid crystal molecules close to the upper substrate, the average value of the pretilt angles of the liquid crystal molecules close to the lower substrate is increased while the pretilt angles of the liquid crystal molecules close to the upper substrate are reduced, the crossing and framing phenomena between the adjacent liquid crystal molecules close to the upper substrate at the junctions of two adjacent domains are effectively avoided in the liquid crystal panel bending process, the dark fringes of the pixel electrode are improved, and the dark cluster phenomenon of the curved surface display area of the liquid crystal panel is improved.

Referring to fig. 4 and 7, in one embodiment of the present invention, the ultraviolet alignment apparatus 100 includes a first illumination unit 110, a second illumination unit 120, and a support unit 130. The first illumination unit 110 and the second illumination unit 120 are disposed opposite to each other, and the supporting unit 130 is disposed between the first illumination unit 110 and the second illumination unit 120 and close to the second illumination unit. In the ultraviolet light alignment process, the liquid crystal panel 200 receives the ultraviolet light from the first light unit 110 and the second light unit 120 for alignment, and among the liquid crystal molecules 231 of the liquid crystal layer 230 in the liquid crystal panel 200, an average value of the pretilt angles of the liquid crystal molecules 231 near the first light unit 110 (i.e., near the upper substrate 210 of the liquid crystal panel 200) is smaller than an average value of the pretilt angles of the liquid crystal molecules 231 near the second light unit 120 (i.e., near the lower substrate 220 of the liquid crystal panel 200).

The conventional alignment uv irradiator 100a employs single-sided illumination, and for a liquid crystal panel, in the liquid crystal alignment process, the upper substrate 210(CF substrate) near the uv light source 120a receives the uv light first, and the intensity of the uv light is high, and the lower substrate 220(Array substrate) far from the uv light source 120a receives the uv light which is attenuated by the upper substrate 210 and the liquid crystal layer 230, and the intensity is weak. Therefore, in the case that the PI material of the upper substrate 210 is the same as the PI material of the lower substrate 220, the upper substrate 210 has a high light intensity due to the ultraviolet light, the liquid crystal molecules 231 of the liquid crystal layer 230 near the upper substrate 210 form a larger pretilt angle, and the lower substrate 220 has a lower pretilt angle due to the lower light intensity of the received ultraviolet light, the liquid crystal molecules 231 near the lower substrate 220 form a smaller pretilt angle.

Referring to fig. 2, since the pixel electrode 240 of the liquid crystal panel 200 includes a plurality of domains 241 (e.g., 4 domains or 8 domains), the tilt directions of the liquid crystal molecules 231 between two adjacent domains 241 are different, and the tilt angles are also different, and for a planar product, the arrangement of the liquid crystal molecules between the lower substrate 220 and the upper substrate 210 is as shown in fig. 3a, although the tilt directions of the liquid crystal molecules 231 at the boundary between two adjacent domains 241 are opposite, the crossing and "shelving" phenomena are not generated, that is, no dark clusters appear on the surface of the liquid crystal panel 200; for a curved product, in the process of bending the liquid crystal panel 200, the lower substrate 220 and the upper substrate 210 may generate relative displacement, referring to fig. 3b, when the lower substrate 220 and the upper substrate 210 are displaced due to bending (the upper substrate 210 is displaced to generate an intersection with the lower substrate 220), the corresponding relationship between the domains 241 of the lower substrate 220 and the upper substrate 210 is misaligned, two liquid crystal molecules 231 with different pretilt angles in different directions exist at the boundary between two adjacent domains 241, and due to the larger pretilt angle of the liquid crystal molecule 231 near the upper substrate 210, the intersection and the "frame hitting" phenomenon occurs at the boundary between two adjacent domains 241 and between the liquid crystal molecules 231 near the upper substrate 210, so that dark fringes occur at the pixel electrode 240, and further, the problem that a curved display region appears dark clusters on the surface of the liquid crystal panel 200 macroscopically is caused.

In the present embodiment, by adding the second lighting unit 120, during the ultraviolet light alignment process, the ultraviolet light alignment is performed on the liquid crystal panel 200 by the second lighting unit 120, since the ultraviolet light emitted by the second lighting unit 120 directly irradiates the lower substrate 220 without passing through the attenuation of the upper substrate 210 and the liquid crystal layer 230, the pretilt angle of the liquid crystal molecules 231 close to the lower substrate 220 (i.e. close to the second lighting unit 120) can be effectively increased, specifically, in the liquid crystal layer 230, the increasing range of the pretilt angle of the liquid crystal molecules 231 closer to the lower substrate 220 (closer to the second lighting unit 120) is larger, and the increasing range of the pretilt angle of the liquid crystal molecules 231 farther away from the lower substrate 220 (farther away from the second lighting unit 120) is smaller, that is, the increasing range of the pretilt angle of the liquid crystal molecules 231 gradually decreases from the end close to the second lighting unit 120 to the end close to the first lighting unit 110, however, since the pretilt angle tends to increase as a whole, the average value of the pretilt angles of the liquid crystal molecules 231 near the second light irradiation unit 120 increases. Due to the existence of the liquid crystal layer 230 and the lower substrate 220, the ultraviolet light emitted from the second illumination unit 120 has no significant effect on the pretilt angle of the liquid crystal molecules 231 in the liquid crystal layer 230, which are close to the upper substrate 210 (i.e., close to the first illumination unit 110). Similarly, the first illumination unit 110 emits ultraviolet light to illuminate the liquid crystal panel 200, and the upper substrate 210 receives the ultraviolet light emitted by the first illumination unit 110, so as to increase the pretilt angle of the liquid crystal molecules 231 close to the first illumination unit 110.

In the present embodiment, the supporting unit 130 includes a supporting base 131 and a supporting frame 132 disposed on an upper surface of the supporting base 131, and referring to fig. 4 and 7, the supporting frame 132 is formed by at least two supporting rods 132a (supporting PINs) arranged at intervals, and the second UV light sources 121 are arranged between the supporting rods 132a at intervals.

In another embodiment of the invention, referring to fig. 5 and 8, the supporting frame 132 includes supporting rods 132b arranged at intervals and a light-transmitting plate 132c arranged at the upper end of the supporting rods 132b, the liquid crystal panel 200 is arranged on the upper surface of the light-transmitting plate 132c, and the second UV light sources 121 are arranged between the supporting rods 132b at intervals. In addition, the supporting frame 132 may also be made of other light-transmitting structures, as long as the ultraviolet light emitted by the second light unit 120 is directly emitted to the liquid crystal panel 200.

In the present embodiment, the second UV light source 121 in the second lighting unit 120 is a UV fluorescent lamp, the first UV light source 111 in the first lighting unit 110 is a UV fluorescent lamp, and taking an 8.5-generation TFT-LCD as an example, the number of the UV fluorescent lamps in the first lighting unit 110 is 140, and the number of the UV fluorescent lamps in the second lighting unit 120 is 140.

In another embodiment, the second UV light source 121 in the second illumination unit 120 is a metal halide lamp, the first UV light source 111 in the first illumination unit 110 is a metal halide lamp, and taking a TFT-LCD of 8.5 generation as an example, the number of metal halide lamps in the first illumination unit 110 is 12, and the number of metal halide lamps in the second illumination unit 120 is 12.

In another embodiment of the present invention, referring to fig. 6 and 9, the second UV light source 121 and the first UV light source 111 are both LED lamps, and taking an 8.5-generation TFT-LCD as an example, the number of LED lamps in the first illumination unit 110 is 140, and the number of LED lamps in the second illumination unit 120 is 140.

The temperature control members 140 are disposed on two sides of the supporting unit 130, the temperature control members 140 are fans, and during the liquid crystal alignment process, because a large amount of heat is generated by ultraviolet light irradiation, the ambient temperature of the liquid crystal panel 200 is controlled by adjusting the air volume of the fans and cooling the air, for example, the ambient temperature is controlled within a range of 30-60 ℃. A fan is provided at one side of the supporting unit 130 or both sides. In another embodiment, a water cooler is used as the temperature control member 140 for controlling the temperature, the water cooler is disposed outside the supporting platform 131, and a water cooling pipeline is laid on the upper surface of the supporting platform 131 for cooling and controlling the temperature.

The light shield 150 is disposed between the first illumination unit 110 and the liquid crystal panel 200, during the liquid crystal alignment process, when the alignment voltage is applied to the liquid crystal panel 200, the light shield 150 is opened to shield the ultraviolet light emitted from the first illumination unit 110, after the alignment voltage is applied, the light shield 150 is closed, and the ultraviolet light emitted from the first illumination unit 110 is directly irradiated to the liquid crystal panel 200.

In one embodiment of the present invention, the pretilt angle of the liquid crystal molecules 231 is changed by the light irradiation time period. In particular, in liquidIn the crystal alignment process, the second light unit 120 first performs ultraviolet light irradiation on the liquid crystal panel 200 for a period of time, and then the first light unit 110 and the second light unit 120 simultaneously perform ultraviolet light irradiation on the liquid crystal panel 200, so that the total irradiation time of the liquid crystal panel 200 receiving the second light unit 120 is longer than the total irradiation time of the liquid crystal panel receiving the first light unit 110, and the average value of the pretilt angles of the liquid crystal molecules 231 close to the lower substrate 220 is longer than the pretilt angle of the liquid crystal molecules close to the upper substrate 210. In the present embodiment, the total duration of the ultraviolet irradiation of the liquid crystal panel 200 by the second irradiation unit 120 is 10 to 150 s; the wavelengths of the first UV light source 111 and the second UV light source 121 are respectively 280-400 nm, preferably 313nm, and the illumination intensities of the first illumination unit 110 and the second illumination unit 120 are respectively 0.3-0.6 mW/cm²。

In another embodiment of the present invention, since the distance between the light-emitting end of the second illumination unit 120 and the lower substrate 220 is greater than the distance between the light-emitting end of the first illumination unit 110 and the upper substrate 210, the average value of the pretilt angles of the liquid crystal molecules 231 near the lower substrate 220 is greater than the pretilt angle of the liquid crystal molecules near the upper substrate 210. In the present embodiment, the distance between the light emitting end of the second illumination unit 120 and the lower substrate 220 is 5-50 cm, and the distance between the first illumination unit 110 and the upper substrate 210 is 90 cm. In addition, the distance between the first illumination unit 110 and the upper substrate 210 can be designed to be 5-100 cm according to the use requirement.

In the above description, the alignment films on the surfaces of the upper substrate 210 and the lower substrate 220 are made of the same material, for example, PI material with model number JSR2503 is selected as the alignment film, no matter the light irradiation interval or the light irradiation duration is changed.

In another embodiment of the present invention, the pretilt angle of the liquid crystal molecules 231 can be changed by changing the material of the alignment film, i.e., the pretilt angle of the liquid crystal molecules 231 can be changed by using different types of PI materials. For example, a PI material having a side chain with a group reactive with the reactive monomer in the liquid crystal molecules 231, such as JALS-2579-R1, SE-H867, etc., is used as the alignment film, and a side chain of these types of PI materials has a group reactive with the reactive monomer in the liquid crystal molecules, and these types of PI materials are used as the alignment film, so that the pretilt angle of the liquid crystal molecules 231 can be further increased.

The ultraviolet alignment device 100 is adopted to perform ultraviolet illumination alignment on the liquid crystal panel 200, and the difference value between the average value of the pretilt angles of the liquid crystal molecules 231 close to the lower substrate 220 and the average value of the pretilt angles of the liquid crystal molecules 231 close to the upper substrate 210 is 1-4 degrees. The range of the difference can be determined by factors such as the illumination time length, the type of the alignment film material, the illumination distance and the like. With the conventional alignment uv irradiator 100a, the difference between the average value of the pretilt angles of the liquid crystal molecules 231 near the upper substrate 210 and the average value of the pretilt angles of the liquid crystal molecules 231 near the lower substrate 220 is 0.1 °.

Referring to fig. 10, the ultraviolet alignment method provided by the present invention includes the following steps:

s101, providing the ultraviolet alignment device 100;

s102, disposing the liquid crystal panel 200 on the upper surface of the supporting frame 132, and applying an alignment voltage to the liquid crystal panel 200;

s103, after the alignment voltage is applied, starting a second illumination unit 120 to perform ultraviolet illumination on the liquid crystal panel 200;

s104, turning on the first illumination unit 110, and simultaneously performing ultraviolet illumination on the liquid crystal panel 200 by the first illumination unit 110 and the second illumination unit 120.

The light shield 150 is disposed between the first light unit 110 and the liquid crystal panel 200, and during the alignment voltage application, the light shield 150 is turned on to shield the first light unit 110, and after the alignment voltage application is completed, the light shield 150 is turned off.

In the ultraviolet illumination process, the temperature control member 140 is started to control the ambient temperature contacted by the liquid crystal panel 200; the ambient temperature of the liquid crystal panel 200 is 30-60 ℃.

The first illumination unit 110, the second illumination unit 120, the temperature control member 140 and the light shield 150 can be controlled remotely through a control panel or a controller.

In the actual alignment, referring to fig. 3b and fig. 11, the liquid crystal layer 230 is divided into three parts, i.e., an upper segment 230a, a middle segment 230b and a lower segment 230c, the upper segment 230a is close to the upper substrate 210, the lower segment 230c is close to the lower substrate 220, and the middle segment 230b is located between the upper segment 230a and the lower segment 230c, as mentioned above, the pretilt angle of the liquid crystal molecules 231 in the upper segment 230a gradually decreases from one end close to the upper substrate 210 to the middle segment 230b, the pretilt angle of the liquid crystal molecules 231 in the lower segment 230c gradually decreases from one end close to the lower substrate 220 to the middle segment 230b, the pretilt angle of the liquid crystal molecules 231 in the middle segment 230b is small and almost zero, i.e., the liquid crystal molecules 231 in the middle segment 230b are in an approximately upright state or an upright state.

Referring to fig. 11, after the ultraviolet alignment apparatus 100 provided by the present invention is used to perform ultraviolet alignment on the liquid crystal panel 200, the average value of the pretilt angles of the liquid crystal molecules 231 located in the upper segment 230a is significantly smaller than the average value of the pretilt angles of the liquid crystal molecules 231 located in the lower segment 230c, and the pretilt angles of the liquid crystal molecules 231 located in the upper segment 230a are reduced, so that the liquid crystal molecules 231 located in the upper segment 230a and located at the boundary between two adjacent domains 241 do not intersect and have a "frame-hitting" phenomenon in the curved segment, thereby avoiding the occurrence of a dark cluster phenomenon and improving the display image quality of the liquid crystal panel.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that various modifications and decorations can be made by those skilled in the art without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.