JP3083709B2 - Color picture tube with improved shadow mask frame support means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collar having a shadow mask mounted on a peripheral frame suspended from a cathode-ray luminescent screen comprising fluorescent elements for emitting blue light, green light and red light. In relation to the picture tube,
An improved means for supporting a mask frame assembly in such a picture tube so that the electron beam generated by the electron gun strikes a suitable fluorescent element.

[0002]

BACKGROUND OF THE INVENTION In modern color picture tube configurations, the peripheral frame supporting the shadow mask is suspended from the face plate panel by a spring welded directly to the frame or to a plate welded to the frame. . In the form of a direct weld, the spring is usually made of a bimetallic material; in the form of a weld to the plate, the plate is bimetallic. Since the spring or plate is heated by heat propagation from the mask through the frame, the bimetal material expands in various ways,
This bends the spring or plate to induce movement of the mask frame assembly in the direction of the screen located on the panel. It is also known to use spring geometries to induce the same movement in the screen direction by the action of forces on the springs of the expanding mask frame assembly.

Typically, three or four springs are used to support the mask frame assembly on the rectangular faceplate panel of the picture tube. In a three-spring support device, one spring is usually centered above the mask, and the other two springs are located between the center on the side of the mask and the two lower corners of the mask. It is placed along the side of the picture tube. In a four spring support device, the springs are typically located in the center above and below the mask and in the center on the left and right sides of the mask. With both three and four spring supports, as described above, during manufacture and / or operation of the picture tube, the mask frame assembly can be slightly twisted and shifted with respect to the faceplate. A known means of minimizing torsion and shift of the mask frame assembly uses spring supports at the four corners of the frame.

[0004]

A problem with the plate-type structure described above is the mounting of the spring on the plate,
It is difficult to non-destructively evaluate the quality of the welds used to attach the plate to the frame. Defective welding occurs due to thermal or mechanical shock, and the welding operation is performed from the welding splash, i.e. from the welding area, due to improper contact between the parts to be joined together and the welding electrodes. May result in released metal shards. Weld splash pieces are trapped in the closed picture tube and can cause cosmetic or electrical problems. Another problem related to welding is that if the parts to be connected are not on the same level surface, a welding nugget will be formed between the parts and the weld will fail under impact load, or the parts and shadow mask Act as a pivot point that can cause relative rotation of Under such conditions, an alignment error occurs between the opening in the shadow mask and the fluorescent element of the cathode-ray emission screen, so that the electron beam hits an area of the screen other than the intended area.

[0005]

SUMMARY OF THE INVENTION An improved color picture tube according to the present invention comprises an evacuated glass envelope having a faceplate panel on which a cathodoluminescent screen is disposed. The panel comprises a color selection electrode assembly attached thereto by support means located at a peripherally spaced location within the panel. The support means includes, at each of the spaced locations, a stud mounted on the glass envelope, a spring having an opening therein for engaging the stud, and a plate welded between the spring and the color selection electrode assembly. Including. The improvement is achieved by mechanically connecting the spring and plate by protrusions that connect the parts together at two spaced apart locations along one edge of the parts.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rectangular faceplate panel 12 and a tubular neck 1 connected by a rectangular funnel 16 are shown.
FIG. 1 shows a rectangular color picture tube 8 having a glass envelope 10 composed of the color envelope 4 shown in FIG. The panel 12 comprises a viewing faceplate 18 and a peripheral flange or side wall 20 enclosed in a funnel 16. The faceplate panel 12 has two orthogonal axes: a long axis XX parallel to the wider dimension (normally horizontal) and a short axis parallel to the narrow dimension (normally vertical). Axis Y-Y. The major and minor axes are the center of the neck 14 and the panel 12
Is perpendicular to the central longitudinal axis Z-Z of the picture tube passing through the center of the picture tube. A three-color fluorescent screen 22 composed of blue, green, and red light-emitting fluorescent elements is carried by the inner surface of the face plate 18. This screen is desirably a line screen with fluorescent lines extending substantially parallel to the short axis YY. Alternatively, the screen may be a dot screen. Color selection electrodes with multiple openings,
Alternatively, the shadow mask 24 can be
It is removably attached to screen 22 in a predetermined spaced relationship. An electron gun 26 is mounted at the center of the neck 14 to generate three electron beams and irradiate the screen 22 along a convergence path through an opening in the curved opening 25 of the mask 24.

The picture tube of FIG. 1 is designed for use with an external magnetic deflection yoke, such as a yoke 28 located near the funnel-neck connection. When activated, the yoke 28 applies a magnetic field to the three beams that causes the beams to scan horizontally and vertically on the screen 22 with a rectangular raster. The shadow mask 24 is part of a mask frame assembly 30 that further includes a peripheral shadow mask frame 32. Mask frame assembly 30 is shown positioned within faceplate panel 12 of FIGS. The mask frame assembly 30 is mounted on the panel 1 by four improved support means 34 shown in FIGS.
2 attached.

The shadow mask 24 has a curved opening 25.
A non-opening boundary 27 surrounding the opening 25;
2 bent backward from the screen and extending from the screen 22
9 is included. The skirt 29 of the mask 24 is fitted into the frame 32 or installed inside and welded to its inner surface. The support means 34 is located at a distance from the periphery of the mask frame assembly 30 and the panel 12. Each support means 34 includes a stud 44 and a spring 4
6 and a plate 48. Each stud 44 is, for example, a conical metal member attached to the side wall 20 of the panel along the long and short axes of a 26D picture tube having a diagonal dimension of 66 cm. The opening 60 of the spring 46 engages the free end of the stud 44. The plate 48 is a bimetal element including a first metal layer 48a and a second metal layer 48b that are stacked or bonded to each other in an opposing relationship. Spring 46 is the first of plate 48
And the second metal layer 48b is attached to the frame 32. Plate 48
The bimetallic metal is selected such that when heated, the plate moves in the direction of the frame and the mask frame assembly 30 moves in the direction of the screen 22. Thus, the coefficient of thermal expansion of the metal layer 48b adjacent to the frame needs to be lower than that of the layer 48a attached to the spring. This temperature compensating structure is 197
U.S. Patent No. 3,80, issued to Morrell on April 9, 2004
No. 3,436.

[0009] Unlike the prior art, the spring 46
Are attached to the plate 48 by mechanically connecting the components together using projections that connect the components along opposing faces, rather than by welding. This protrusion is formed at two spaced apart locations 50 and 51 along one edge 52 of the connected component. FIG. 4 shows a cross section of the connecting protrusion. In this embodiment, the center of the protrusion is about 19.50 mm (0.750 inch) and about 4.78 mm (0.188 inch) from the edge 52 of the connected component. The other end of the plate 48 is connected to the frame 3 using conventional welding or a projection of the above-described shape.
2 attached. Attachment points 53 and 54 shown in FIG.
Are spaced approximately 25.4 mm (1.00 inches) apart from the opposing edge 55 of the plate 48.
8 inches) apart. Mounting positions 50 and 51 and point 5
The lateral distance A between 4 and 54 is approximately 0.874 inches to provide a suitable position for the movement of plate 48 to achieve temperature compensation.

The outer spring 46 and the inner plate 4
Position 5 to connect 8 in a clamping manner
The coupling projections provided at 0 and 51 are, for example, Tech-Line Engineering, Warren, Michigan;
Or, it made form using conventional clamping devices available from BTM Corp. of Michigan Merisubiru. External to conventional mounting means such as welding or riveting
Parts and inner parts in such a way that they
The advantage of the connecting projections to tie is that the weld splash is removed, the quality of the tightening can be inspected non-destructively, the accuracy of the tightening position is high, there is no need to pre-form holes for rivets, and the riveting The additional components required are eliminated . A disadvantage of the consolidated protrusion "good" with nugget size of the same size as the connecting protrusion
It is to not only obtain about 70% of the intensity of the strength of the weld, however, by slightly increasing the size of the protrusions, it is possible to obtain a considerable tightening strength.

An unexpected advantage of the coupling projection is that a shadow mask assembly utilizing the novel coupling projection to attach the associated spring 46 and plate 48 to each other can be used for impact tests and for panels mounted there. The result of the static load test is to be improved. Impact tests were performed on twelve test panel assemblies made with connecting lobes at locations 50 and 51. The test assembly was evaluated against a conventional eight (control) panel assembly with springs welded to the plate. Both the test and control panel assemblies had the plates welded to the frame of the shadow mask assembly.

The panel was manufactured using conventional matrix processing as described in US Pat. No. 4,049,452, issued Sep. 20, 1977. The photoresist solution, which changes its solubility when exposed to light, is deposited on the inside surface of the panel and dried. The shadow mask assembly is mounted on a panel and light from a light source is emitted through openings in the mask to expose selected areas of the photoresist. In this example, the light source guides the light at the same angle as the electron beam that strikes the green light emitting phosphor. The mask assembly is removed from the panel,
The more soluble portions of the photoresist that have not been exposed are removed by washing. A solution of the light absorbing matrix material is then deposited on the exposed areas of the panel and on the retained areas of the exposed photoresist. The matrix solution is dried and etched with a suitable etchant. This etchant softens and removes the retained area under the photoresist and the upper matrix material, forming at the location previously occupied by the retained area under the photoresist and the upper matrix material. Erased windows are removed leaving a light absorbing matrix material on most of the panel.

The windows in the matrix provide a way to measure the alignment shift. As described above, when a window is formed and the shadow mask assembly is held in the panel, light from the exposure light source passes through the open window and the position of the light uses a device called a matrix alignment reader. And read correctly. The panel is then impacted by a drop test in which the shadow mask assembly impacts the panel carried thereon with 35G. Here, G is gravity. The panel assembly is impacted by the panel in the normal viewing direction. The impact in this direction is indicated by "Y" in Table 1, and "FD" when the surface of the panel assembly faces downward, and "F" when the surface faces upward.
U ". A separate panel is used for each test.
Prior to the impact test, the panel assembly should be 450 ± 15
It is thermally stressed by passing it through a stabilizing furnace operating at a temperature of ° C. The cycle of thermal stress is repeated five times to give the "worst case" condition for each panel. Table 1 shows the results of the drop test. "C" indicates a control picture tube conventionally welded with a spring and a plate,
"T" indicates a test picture tube where the spring and plate are connected by the protrusions shown in FIGS. There are seven alignment shifts for each panel assembly:
Center (CTR); about 25 mm from the edge of the screen (2D, 8D, 4D and 10D) along each diagonal; and
Measured along the long axis (3:00 and 9:00). The displayed measurements illuminate through the mask assembly and window from the same light source used to form the window in the matrix, and then displace or "alignment error" due to the 35G impact. Was obtained by measuring the amount of
This value is given in micrometers (μ); the smaller the absolute value of the displacement, the less the alignment shift. The plus (+) and minus (-) signs relate to a shift in one direction or the other.

[0014]

[Table 1]

By comparing the alignment shifts for the control and test panels dropped with the panel assembly in the normal viewing direction (Y), at the center, the test and control panels have equal amounts of alignment error. It was found to have However, 2D, 3: 0
At the 0, 4D, 9:00 and 10D positions, the absolute value of the registration error for the test panel is in the range of 2-5 μ less than the control panel, and at the 8D position, the average of the test panel is the control. 5 μm larger than the alignment panel. On average, for the impact test in the Y direction, the overall alignment error of the test panel is smaller than the control panel. Face up (F
In the drop test in the U) position, the test panel showed a center, 2D, 3:00,
And a favorable result with a small alignment error was obtained at the position of 4D, but at the positions of 8D, 9:00 and 10D, the alignment error was slightly large. Test with face down (F
In D), the test panel did not give better results than the control panel, but all the results were poor.

The static load test results for two additional picture tubes made by conventional welding and two test picture tubes with springs attached to the plate using the novel connecting projections are shown. The results are shown in Tables 2 and 3, respectively.

[0017]

[Table 2]

[0018]

[Table 3]

In the static load test, the corner of the frame,
Pressure is applied to the 2D (2 o'clock) corner, and the displacement of the light source through the aperture of the matrix is recorded at the corners (2D, 4D, 8D and 10D) and the major axes (3:00 and 9:00) Was done. All measurements are taken about 25 mm from the edge of the screen. This pressing force is 5 pounds (2.268 kg).
And the corresponding displacement was recorded.

The plates and springs of test tubes T13 and T14 are mechanically connected by new projections connecting the parts. The plates and springs of the control picture tubes C11 and C12 are connected by conventional welding. As described above for the impact test picture tubes, both the test and control picture tube plates are welded to the shadow mask frame. The coupled plates and springs of test tubes T13 and T14 provide greater resistance to displacement or registration errors than control tubes. This can be inferred by comparing the maximum displacement at the non-contacting corner (10D) as the static load at corner 2D increases from 40 to 50 pounds. The 45 pound test load simulates the force on the mask frame assembly when the panel with the mask frame assembly mounted thereon is mishandled during manufacture and the mask frame comes into contact.

Referring to Table 2, when a 40 pound load is applied to corner 2D of the control picture tube, the largest displacement at the non-contacting corner occurs at the 10D corner of the control picture tube, Here, the positioning errors are 11 and 12 μ, respectively. However, as shown in Table 3, by applying the same 40 lb load to corner 2D on the test picture tube, displacements of 4 and 0μ are obtained at corner 10D, respectively. Corner 2
When the load at D is increased to 55 pounds, the corresponding displacement at corner 10D relative to the control picture tube is:
As shown in Table 2, they are 35 and 40μ; whereas, the displacements for the test picture tube are only 19 and 13μ, respectively, as shown in Table 3.

Although the invention has been described with reference to support means mounted on the long and short axes of the panel and shadow mask frame assembly, the support means may be provided at other locations on the panel and mask frame assembly. As shown in FIGS. 5, 6 and 7, support means 34 'are included at each of the four corners of mask frame assembly 30' and panel 12 '. The same components as those shown in FIGS. 1 to 4 are labeled with the same reference numerals. Each support means 34 'is provided with a stud 44'
And a spring 46 'and a plate 48'. Each plate 48 'is welded near one end at the chamfered corner of the frame 32'. This welding may be conventional, or the welding of frame 3 at points 53 'and 54'.
A pair of new protrusions connecting the 2 'to the plate 48' may be used. The spring 46 'is attached at one end to the other end of the plate 48' by a projection connecting the parts to one another at positions 50 'and 51' in the manner shown in FIG. 4 for the first embodiment. Spring 46 'has an opening 60' near its free end that engages the conical portion of stud 44 '.

As shown in FIG. 6, the plate 48 'has a laminated bimetal structure. One metal layer 48a 'facing the frame 32' is a material having high thermal expansion, and the other metal layer 48b 'facing the spring 46' is a material having low thermal expansion. Spring 46 'and plate 4
Each of 8 'compensates for the thermal expansion of mask 24' during picture tube operation and contributes to the compensation needed to move mask frame assembly 30 'relative to the screen. The extent of the spring and plate contributions was described on 5 November 1991 in Lagrand, Jr. U.S. Patent No. 5,062 issued to
No. 3,325.

[Brief description of the drawings]

FIG. 1 is an axial side sectional view of a color picture tube according to an embodiment of the present invention.

FIG. 2 is a schematic rear view of a faceplate panel supporting a shadow mask assembly according to a preferred embodiment of the present invention.

3 is a cross-sectional view taken along line 3-3 of FIG. 2 showing a portion of the shadow mask assembly and its support means.

FIG. 4 is a view showing details of a connecting protrusion of the support means;
4 is a cross-sectional view of FIG.

FIG. 5 is a schematic rear view of a quarter of a faceplate panel and shadow mask assembly according to another preferred embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of a corner of the panel-shadow mask assembly of FIG. 5;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5 showing the corner support means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Glass envelope 12, 12 'Faceplate panel 14 Neck 16 Funnel 18 Viewing faceplate 20 Peripheral flange or side wall 22 Fluorescent screen 24, 24' Shadow mask 25 Curved opening 26 Electron gun 27 No-opening boundary 28 Yoke 29 Hem 30, 30 'mask frame assembly 32, 32' frame 34, 34 'support means 44, 44' stud 46, 46 'spring 48, 48' plate 48a, 48b, 48a ', 48b' metal layer 50, 51, 50 ', 51' Position of protrusion 52 Edge of part 53, 54, 53 ', 54' Mounting point 60, 60 'Opening

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Raymond Edward Keller United States Pennsylvania 18411 Clarks Summit Lore Le Hill Road 2064 (72) Inventor Joseph John Piassinski United States Pennsylvania 17540 Leora Pleasant Valley Drive 305 (72) Inventor Neil Edward Cies United States of America Pennsylvania 17543 Lititz Ridings Way 86 (56) Bibliography Shokai 56-172249 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) H01J 29/02

Claims (10)

(57) [Claims] 1. An assemblage comprising: an evacuated glass envelope having a faceplate panel with a cathodoluminescent screen mounted on an inner surface thereof; and a color selection electrode assembly mounted in spaced relation to said screen. The three-dimensional object is fixed to the panel by supporting means disposed at a position spaced apart from the peripheral side, and the supporting means has a stud, a spring, and a plate attached to the panel at each of the separated positions, and the plate is attached to the plate. The mounted spring has a stud engagement opening, and the plate is a color picture tube fixed to the color selection electrode assembly, wherein the spring and the plate are one of the spring and the plate. mutually clamping one another outside of the spring and the inside of the plate at two spaced locations along the edge of
A color picture tube that is mechanically connected by protrusions that are connected in an unusual manner . 2. The picture tube according to claim 1, wherein said face plate panel has a rectangular shape, and a position separated from the periphery of said support means is along a side of said panel which is arranged opposite to said panel. 3. The picture tube according to claim 1, wherein said face plate panel has a rectangular shape, and a position separated from the periphery of said support means is at a corner of said panel. 4. The plate clamps the plate and the color selection electrode assembly together at two spaced apart points.
2. The picture tube as claimed in claim 1, wherein the picture tube is mechanically connected to the color selection electrode assembly by an additional projection connected in such a manner . 5. The picture tube according to claim 4, wherein said separated point is along an edge of said plate opposite one edge attached to said spring. 6. An evacuated glass envelope having a rectangular panel with a viewing portion and a peripheral side wall connected to the viewing portion, and disposed on an inner surface of the viewing portion of the panel. A cathode ray luminescent screen comprising fluorescent elements that emit various colors, and a rectangular shadow mask assembly in the panel mounted in a spaced relationship with the screen, wherein the shadow mask assembly is opened. A frame and a frame, wherein the aperture of the open section is aligned with the fluorescent element of the screen, and the assembly is mounted in the panel by support means located at a peripherally spaced position;
The support means includes a stud attached to the side wall of the panel at each of the spaced locations, wherein the spring and the bimetal plate have a first metal layer and a second metal layer in opposing relation; The first and second metal layers have different coefficients of thermal expansion, and the spring having a stud engagement opening is mounted in contact with the first metal layer of the plate and the second of the plate. the metal layer is a color picture tube which is fixed to the frame, said spring and said plate, said spring and one along the edge two spaced outer <br/> the spring at the location of the plate And tighten the inner plates together
Are mutually mechanically connected such by protrusions linking in a manner such, the protrusion extends into the spring from the plate, the spring and the plate along the opposite surfaces
The contacting and connecting protrusions provide the spring and the plate with resistance to rotation caused by impact,
Thus, a color picture tube that minimizes an alignment error between the opening of the shadow mask and the fluorescent element of the screen. 7. The picture tube according to claim 6, wherein the position separated from the periphery of the support means is on a side of the panel that is opposed to the panel. 8. The picture tube according to claim 6, wherein a position separated from the periphery of said support means is at a corner of said panel. 9. The plate is mechanically connected to the frame by an additional protrusion that couples the plate and the frame at two spaced apart points in a manner that clamps the plate and the frame together. Item 7. The apparatus according to Item 6. 10. The picture tube according to claim 7, wherein said spaced point is along an edge of said plate opposite one edge attached to said spring.