JPS5832889B2 - Alignment method of electron gun unit using reflected light beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for aligning an electron gun unit of a multiple cathode ray tube, in particular a color television picture tube, with a reflected light beam with respect to a phosphorescent spot on a screen plate.

Current color television picture tubes have a display screen with phosphorescent spots that emit light in the three primary colors red, green, and blue, and a color-selective electrode plate that extends substantially parallel to the display screen. .

The phosphorescent spots are deposited, for example, by photochemical treatment, and the position of the phosphorescent spots on the screen plate is precisely formed with respect to the axis of the electron gun corresponding to each phosphorescent spot.

The arrival point of the electron beams on the screen plate must exactly match the position of the phosphorescent spot corresponding to each electron beam.

In the case of a color television picture tube (delta configuration) in which the electron gun is arranged, for example, at the apex of a triangle, the electron gun unit receives the image so that it is within a displacement angle of less than 3 degrees with respect to the position of the phosphorescent spot on the screen plate. It must be fixed inside the neck of the tube.

In the case of color television picture tubes in which the electron gun is arranged in a straight line (in-line configuration), more precise positioning is necessary, for example for color television picture tubes in which special dynamic focusing means are used. be.

One conventional method used in color television picture tubes using electron guns in a delta configuration uses contact pins on a pressed glass base as marks for aligning the electron gun unit.

These contact pins are connected to the electron gun by metal wires or metal tapes, so that the electron gun together with the pressed glass base forms one structural unit.

However, the thin metal wire or metal tape can be easily bent, causing the electron gun unit to be misaligned with respect to the molded glass base and therefore also with respect to the phosphorescent spots on the screen plate, causing it to deviate significantly from tolerances. .

DE 2354338 discloses a method, according to which the electron gun unit has a reference plane that includes the center points of at least two passage holes for the electron beam provided in the acceleration and focusing grid. It is used for consistency.

This grid consists of two cap-shaped parts with their bottoms facing each other.

The bottoms of these are provided with electron beam passage holes.

The cap-like portion of the grid used in in-line picture tubes has, for example, flat sides extending parallel to a plane containing the central axis of the electron gun.

Two mechanical measuring rods formed by displaceable rods are arranged in the grid when the electron gun unit and the picture tube are placed separated from each other in a confinement device that confines the electron gun unit within the picture tube. It is adapted to make contact with one of the flat sides.

These measuring rods measure the distance between the reference plane representing the ideal position of the electron gun unit relative to the screen plate and the contact point of the measuring rod on the flat side of the grid.

Alignment is made possible by rotating the electron gun unit about its central longitudinal axis to equalize the two measured distances while monitoring the comparator.

The observation plane determined by the two contact points then becomes parallel to the reference plane.

The rotational angle tolerance of the electron gun unit is about 0.5 degrees or less.

A disadvantage of such mechanical alignment is that the electron gun unit is easily twisted, bent, or damaged due to the use of a mechanical measuring rod on the electron gun unit.

In order to obtain accurate measurements, the two measuring rods must be laterally separated from each other as much as possible.

Since the glass base and the electron gun unit may be displaced parallel to each other during assembly, it is easy for one of the measuring rods to touch or even cross the edge of the flat side of the grid, which may cause problems during the measurement process. Depending on the situation, it may even damage the electron gun unit.

According to the present invention, the electron gun unit is aligned with respect to the screen plate of the picture tube when the electron gun unit and the picture tube are arranged separately from each other in a confinement device that confines the electron gun unit within the picture tube. A position setting alignment method is provided which obviates the above-mentioned drawbacks of conventional methods.

In this method, at least two light reflective marks are provided on the outside of the opposing parts of the electron gun unit, a light beam from a light source is projected onto the marks, and the intensity of the reflected light beam is converted into an electrical signal by a photoreceptor. , is achieved using an alignment method that sets the precise position of the electron gun unit relative to the picture tube.

The present invention provides the benefit of using non-contact measurement techniques.

That is, the measuring section with the light source and the photoreceptor is placed sufficiently away from the housing tube housing the electron gun unit in a confinement device that confines the electron gun unit within the picture tube, so that the electron gun unit is not exposed to the electron gun unit during the alignment operation. Avoiding damage.

Additionally, this method can direct rotational movements on the order of about 0.1 degrees, allowing for more accurate alignment adjustments.

Hereinafter, the present invention will be explained by way of examples with reference to the accompanying drawings.

FIG. 1 shows an embodiment for illustrating and explaining the method according to the invention in principle.

In contrast to a containment device (not shown) that confines the electron gun unit within the picture tube, the picture tube and the electron gun unit connected to the press-molded base are arranged with respect to each other.

The concentration pot 6 of the electron gun unit is fixedly supported on a spindle rotatable about its axis.

The axis of the spindle, the axis of the electron gun unit, and the axis of the picture tube are aligned.

The marks 21 and 22 are formed, for example, by forming anti-reflection films having an appropriate shape on opposing peripheral outer portions of the electron gun unit.

Furthermore, in this case, the central pot 6 is the place where the mark is placed.
may be selected.

The grid also serves as a set point for attaching these marks.

This is because according to the present invention, the light beam does not pass through the aperture provided in the grid, and therefore there is no need to consider changes in electrostatic characteristic values caused by the light beam passing through the aperture. be.

One light source 23, 2 is provided on each side of the electron gun unit.
4 and one photoreceptor 25,26 are provided.

In this way, the light source 23.24 and the photoreceptor 25.26
Alternatively, the electron gun units are prevented from coming into contact with each other.

Preferably, the light source projects light in the infrared region, since infrared light is less affected by the surroundings than visible light.

However, visible light is also suitable for use.

In that case, there is a wide range of possibilities for using or selecting photoconductive media and photoreceptors.

The light source 23,24 is placed within the focus of the collimator lens 4L44.

In front of the collimator lens, diaphragms 42 and 43 each having a rectangular opening with a side length of about 7×10 wl1 are provided.

As a result, from said aperture a light beam (shown only by the axis in this figure) with limited directionality is projected towards a reflective mark 21,22 provided on the concentration pot 6 of the electron gun unit.

The light beams reflected at marks 21° and 22 are each
two diaphragms 46, 47 and edge filters 45, 4
8, it collides with the photoreceptor 25, 26.

The edge filters 45 and 48 pass only the light generated from the light sources 23 and 24 and exclude other light.

After the light beam is projected onto mark 2L22 at a certain angle,
The reflected light beams reach respective photoreceptors 25,26.

When the electron gun unit rotates by an angle Aα with respect to the ideal position, the angle change of the reflected light beam becomes 2Aα.

This indicates that even slight changes in the rotation angle can be detected.

When the mark 2L22 is formed as an antireflection film, the electron gun unit is ideally aligned with respect to the picture tube when the intensity of the reflected light beam received by the photoreceptors 25 and 26 is minimized.

The surface of the concentration pot 6 is made of metal.

Therefore, when a light beam is incident on a metal surface, most of the light beam is reflected, and the intensity of the light beam received by the photoreceptors 25 and 26 is maximized.

However, as shown in FIG.
, 22, most of it is absorbed and the photoreceptor 25,
The intensity of the light beam received by 26 is minimal.

FIG. 2 shows another embodiment of the method of the invention.

When marks 21 and 22 are illuminated by scattered light from light sources 33 and 34, lenses 27 and 28 and filter 35
, 36 forms an image within an aperture in the diaphragm 29,30.

The marks 21 and 22 are each formed of a reflective film.

The photoreceptor 3L32 is arranged behind the openings of the diaphragms 29 and 30.

For good positional alignment, the intensity will be maximum on both photoreceptors simultaneously.

Even if the electron gun is shifted parallel to the axis connecting both photoreceptors 3L32, the maximum intensity value appears depending on the continuing rotation angle.

The distance between the intensity maxima with respect to the angle of rotation allows the parallel deviation to be measured directly.

The ideal position is obtained by dividing the rotation angle in half between the two peaks of maximum strength.

As described above, according to the present invention, the correct position of the electron gun with respect to the picture tube can be determined by converting the intensity of the light beam reflected by the mark provided on the electron gun unit into an electrical signal. Accurate alignment operations can be performed without damaging the electron gun unit during alignment, unlike the automatic measurement method.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are explanatory diagrams showing the basic structure of the method according to the present invention, respectively. 6... Concentrated pot, 21.22... Light reflective mark,
23, 24... Light source, 25.26... Photoreceptor, 2
7゜28...Luns, 29,30...Diaphragm,
31° 32... Photoreceptor, 33, 34... Light source, 35
, 36... Filter, 41... Lens, 42, 43
...Diaphragm, 44...Lens, 45...Filter, 46°47...Diaphragm, 48...Filter.

Claims (1)

[Claims] 1. A method for aligning an electron gun unit with a phosphorescent spot on a screen plate of a multiple cathode ray tube such as a color television picture tube, the method comprising: applying two opposing anti-reflection coatings to the electron gun unit; The electron gun unit is provided so that the straight line connecting the center points of the antireflection film and the axis of the electron gun unit are perpendicular to each other, and the electron gun unit is held by a rotatable spindle, and the spindle, the electron gun unit, and the picture tube are coaxial. In a method for aligning an electron gun unit using a reflected light beam, which determines the relative position of the electron gun unit and picture tube before sealing the electron gun unit in the picture tube, both anti-reflection coatings are aligned. Two light sources and one photoreceptor are arranged on both sides of the electron gun unit, and a light beam is emitted from each light source toward the anti-reflection film, and then reflected by both anti-reflection films and projected onto the photoreceptor. A filtering means is provided in front of the photoreceptor to remove disturbance light from sources other than the light source, and when the electron gun unit is rotated by a spindle and the amount of light received by both photoreceptors becomes the minimum, A method for aligning an electron gun unit using a reflected light beam, characterized in that the alignment position of the electron gun unit is determined. 2 A method of aligning an electron gun unit with a phosphorescent spot on a screen plate of a multiple cathode ray tube such as a color television picture tube, in which two opposing reflective films are attached to the electron gun unit, and the center points of both reflective films are connected. The electron gun unit is provided so that the straight line and the axis of the electron gun unit are perpendicular to each other, and the electron gun unit is held by a rotatable spindle, and the spindle, the electron gun unit, and the picture tube are arranged coaxially. In a method for aligning an electron gun unit using a reflective light beam, in which the relative position of the electron gun unit and picture tube is determined before the electron gun unit is sealed in the picture tube, one light source, one photoreceptor, and one photoreceptor are used for both reflective films. are placed on both sides of the electron gun unit, and the straight line connecting both photoreceptors is perpendicular to the axis of rotation of the spindle, and the scattered light from both light sources is directed toward each reflective film, and then the scattered light is irradiated onto both reflective films. The reflected light beam is projected onto each photoreceptor, a filtering means is provided in front of the photoreceptor to remove disturbance light from sources other than the light sources, and the electron gun unit is rotated by a spindle to separate each beam. A reflective light beam characterized in that beam images are sequentially focused on a photoreceptor, and the alignment position of the electron gun unit is determined when the amount of light received by each photoreceptor reaches a maximum. How to align the electron gun unit.