JP2005529460A - Image display device capable of reducing power for deflection - Google Patents

Abstract

The image display device according to the present invention comprises an elongated display screen (8) and a cathode ray tube (1) having a deflection system (9) for deflecting an electron beam. The display screen is substantially rectangular and has a major axis and a minor axis. The cathode ray tube 1 includes a neck portion and a cone portion (3, 3a) disposed between the neck portion and the display screen. The cone portion has an aspect ratio of 1 or less (ratio between X dimension and Y dimension, that is, X / Y ratio) in the vicinity of the cervical portion, and this aspect ratio corresponds to approaching the display screen, that is, It changes to a value exceeding 1 as the Z value increases.

Description

  The present invention generally relates to an image display device, and in particular, an elongated display screen having a major axis and a minor axis, a cone part, a neck part having means for generating three inline electron beams, and the screen mounted on the cone part. The present invention relates to an image display apparatus comprising a cathode ray tube having a deflection system for generating an electromagnetic field for deflecting the electron beam with respect to the screen, the line scanning direction being parallel to the long axis of the screen.

  Patent Document 1 discloses an image display device having a CRT (cathode ray tube) composed of a conical portion whose cross-sectional shape gradually changes from a circular shape to a rectangular shape from the neck portion side to the display screen side.

  Since the deflection system in such a configuration can be arranged at a position closer to the envelope of the electron beam as compared with the configuration of a CRT having a circular cross-section cone, the magnetic loss is reduced, and thus the required deflection power is reduced. sell.

  In addition, according to the structure of patent document 1, the reduction of the electric power for deflection | deviation of 17% to 25% can be implement | achieved.

However, there is a demand for further reduction in power consumption of the deflection system.
US Pat. No. 5,962,964

  Accordingly, an object of the present invention is to provide an image display device that realizes further reduction in deflection power.

  In order to achieve the above object, an image display device according to the present invention has a first cross-section having a major axis and a minor axis that intersect with each other, with the outer circumferential cross-section of the cone section being located near the neck. The short axis of the first cross section is configured to be parallel to the long axis of the display screen (aspect ratio <1), and the outer peripheral cross section of the cone is located further away from the neck. And having a second cross section having a major axis and a minor axis intersecting each other, and configured so that the minor axis of the second section is parallel to the minor axis of the display screen (aspect ratio ≧ 1). Is characterized by

  With the configuration of the present invention, the power consumption for deflection of the image display apparatus can be reduced.

  In the known design, when the X direction is parallel to the long axis of the display screen, and this long axis is further parallel to the line scanning direction, the aspect ratio of the cross section of the cone portion (that is, X dimension and Y The ratio to the dimension) gradually changes from the aspect ratio of the neck (usually 1) to the aspect ratio of the display screen (for example, 4/3 or 16/9). In the cathode ray tube according to the present invention, the portion of the cone portion in the vicinity of the neck portion has a substantially rectangular cross-sectional shape, and the orientation of the major axis and the minor axis here is determined by the major axis of the sectional portion being Instead of being parallel to the long axis of the display screen, the short axis is configured to be parallel to the long axis of the display screen. Although it seems strange and counter-intuitive to set the first cross section of the cone part to “reverse orientation” by common sense, the inventors of the present invention have the first part near the neck part of the cone part. It has been discovered that the power consumption for deflection can be reduced by reversing the orientation relationship between the major axis and the minor axis in one cross-section (ie, the portion where the initial deflection of the electron beam realized by the deflection system occurs). According to the configuration of the present invention, it is possible to bring the line deflection coil closer to the deflected electron beam at the place where the initial deflection is realized when viewed on the average. Most of the deflection power is used by the line deflection coil. As a sacrifice by reducing the power required for line deflection in this way, the distance between the deflected electron beam and the frame deflection coil is increased, resulting in an increase in the required power for frame deflection. From a practical viewpoint, the power consumption for deflection can be reduced.

  Preferably, the three in-line electron beams are positioned in the in-line plane, the in-line plane is parallel to the long axis of the display screen, and the first cross section is in a direction parallel to the long axis of the display screen. The minimum value of the aspect ratio between the outer peripheral dimension of the cone part and the outer peripheral dimension of the cone part in the direction perpendicular to the major axis of the display screen is in the range of 0.60 to 0.95, more preferably 0. It is in the range of 70 to 0.90.

  The aspect ratio of the screen itself can take values such as 4/3 or 16/9. The cone portion has an aspect ratio of less than 1 near the cervical portion, and this aspect ratio changes to a value of 1 or more as it approaches the display screen from the cervical portion, and the aspect ratio of the display screen near the display screen. (This value corresponds to, for example, 4/3 or 16/9 depending on the design of the cathode ray tube screen).

  If the minimum value of the aspect ratio is too small (less than 0.70, or even less than 0.60), the design of the cone part becomes complicated, which is much larger than the design of the deflection unit and the deflection coil. Change is required. In addition, when the minimum value of the aspect ratio is greater than 0.95, the effect of the present invention cannot be obtained sufficiently.

  It should be noted that the effect of the power saving for change realized by the present invention (which can be further reduced by several percent compared to the conventional configuration) can be used, for example, to enlarge the maximum deflection angle of the electron beam. is there. In a preferred embodiment of the present invention, for example, a configuration with a maximum deflection angle of 120 ° or more can be realized. Such enlargement of the maximum deflection angle is useful in constructing a thin CRT.

  FIG. 1 shows an image display apparatus according to a preferred embodiment of the present invention. The image display device includes a cathode ray tube 1 having a display window 2, a cone portion 3, and a neck portion 4. The neck 4 is provided with means 5 for generating three in-line electron beams 6, and each means 5 is oriented in a so-called in-line plane. An electron gun is usually used as a means for generating an in-line electron beam. The inner surface of the display window 2 includes a number of fluorescent elements, and these fluorescent elements form a display screen 8. When one or more electron beams 6 collide with the fluorescent element, the fluorescent element emits fluorescence to form a visible bright spot on the display screen. In a state where the electron beam 6 is not deflected, the middle electron beam 6 of the three electron beams 6 substantially coincides with the tube axis 7 of the cathode ray tube 1. In the following description, the direction along the tube axis 7 is represented as the Z direction. The direction along the major axis of the display screen 8 is represented as the X direction, and the direction along the minor axis of the display screen 8 is represented as the Y direction. The line scanning direction (that is, the direction of the most frequently performed scanning) in this apparatus is parallel to the long axis (X direction) of the display screen 8. The electron beam 6 is deflected by a deflection system 9 that covers a part 3 a of the cone portion 3 on the way to the display screen 8. The invention is particularly characterized by the outer shape of this part 3a. The deflection system 9 includes a line deflection sub-system 12 and a frame deflection sub-system 13 for forming a two-dimensional image on the display screen 8. In this embodiment, the deflection system 9 has a set of coils corresponding to the line deflection sub-system 12 and a set of coils corresponding to the frame deflection sub-system 13. The outer periphery of the cone portion 3 includes a first portion I located near the neck portion 4 and a second portion II located away from the neck portion 4 and toward the screen 8.

  The plane 11 corresponds to a so-called deflection surface. The deflection surface corresponds to the surface that appears as if it were the origin of the deflected beam, as indicated by the deflected beam 10. Furthermore, in this figure, the X direction corresponding to the direction of the long axis of the display screen and the Y direction corresponding to the direction of the tube axis are shown. The Z-axis coordinate of the deflection surface is normally set to zero, and the coordinate on the display screen side is set so as to take a positive value (this assumption is also assumed in the description of the embodiment of the present invention below). And).

  In a general CRT, the inline plane is oriented parallel to the long axis of the display screen. In the display device according to the present invention, the in-line surface can be oriented parallel to the long axis 21 (see FIGS. 2-5) or parallel to the short axis 22 (FIGS. 6-6). 7).

As shown in FIG. 2, the display screen 8 is formed in a rectangular shape, and has two orthogonal symmetry axes, that is, a long axis 21 having a length L _SCR and a short axis 22 having a length S _SCR . In order to represent the degree of expansion of the display screen 8, the aspect ratio of the display screen 8 is defined as A _SCR = L _SCR / S _SCR . Depending on the design of the display screen 8, this aspect ratio A _SCR is typically 4/3 (1.333) or 16/9 (1.78).

  The present invention is characterized by the aspect ratio of the cone portion, and particularly by the aspect ratio of the portion of the cone portion below the deflection system. In a general design, the outer periphery of the cone portion has a generally circular shape (the aspect ratio is 1, and in this case, the inside of the deflection system is also substantially circular), or gradually from the circular shape (aspect ratio 1). Changes to a rectangle corresponding to the aspect ratio of the display screen.

  The aspect ratio of the cone portion in the image display device according to the embodiment of the present invention is less than 1 in the first portion (that is, the portion in the vicinity of the neck portion), and is larger than 1 depending on the Z coordinate value. It changes to value.

FIG. 3 represents such a design. This figure shows the shape of the outer periphery of the cone according to the Z coordinate value. Each outer periphery shown here is a substantially horizontal portion 31 (a portion extending in the X direction or scanning direction) having a large radius of curvature, and a substantially vertical portion 32 (a portion extending in the Y direction or frame direction) having a large radius of curvature. Part) and a corner part 33 having a center of curvature 34. The smallest cross section shown here corresponds to the part closest to the neck, which in this example is circular. That is, here, the first cross-sectional portion has a circular shape. Further, here, the smaller the cross-sectional portion, the closer to the neck portion, and the largest cross-sectional portion corresponds to the portion closest to the display screen (that is, the portion having the largest Z coordinate value). For some of the cross sections shown here, the corner radius of curvature 34 is shown. Here, the angle θ _max formed by the maximum radius in the cross section from the center (x, y) = (0, 0) (that is, the maximum value of x ² + y ² in the cross section of the corresponding Z value) is shown.

  As shown by the innermost cross section in FIG. 3, the Y dimension takes a larger value than the dimension in the cross section having a small Z value, that is, the cone portion closest to the neck. For example, in this figure, the X: Y ratio is 18:22 in the cross-sectional portions to which the reference numerals 31 to 34 are given. This means that on the outer periphery of the cone portion, the dimension in the Y direction is larger than the dimension in the X direction, that is, this portion extends in the frame direction. Further, the aspect ratio X: Y is larger than 1 in a large cross-sectional portion (a portion having a large Z value). For example, in the largest cross-sectional portion shown in this figure, the X dimension is 60 and the Y dimension is 56. Energy loss can be reduced by such a change in the shape of the outer periphery of the cone portion, that is, a change from a shape extending in the frame direction (near the neck portion) to a shape extending in the scanning direction (screen side). This is because the line scanning deflection coil can be brought closer to the electron beam. Lines 36 shown in this figure each indicate the position of the deflected beam in the maximum deflection state with 6% overscan. Furthermore, in this preferred embodiment, the neck itself has a circular shape.

Here, the angle θ _max (that is, the angle formed by the arrow and the X axis shown in the figure) gradually changes from an angle (near the cervical portion) far exceeding 45 degrees and falls below 45 degrees, and the aspect ratio of the display screen A Approaches the angle corresponding to the arc tangent (inverse tangent) of the _SCR .

  The outline of the cone part can be calculated, for example, by the mathematical construction method shown below (but the present invention is not limited to this method). Here, it is assumed that the radii of curvature of the portions 31, 32, and 33 are respectively constant throughout the entire cone (but the radii of curvature of the portions 31 and 32 are usually larger than the radii of curvature of the portion 33, so The radii are usually different from each other). In this embodiment, the radius of curvature of the portion 33 is set to be equal to the radius of curvature of the neck portion in order to smooth the transition from the neck portion to the cone portion. Thus, the strength of the cone portion can be ensured by smoothing the transition from the neck portion to the cone portion. By looking at each point on the line 36, that is, the position of the deflection beam, the position of the center point 34 is perpendicular to the curved portion 33, and by drawing a line through the line 36 that forms an angle of 30 ° with the X axis. Desired. In FIG. 3, this is indicated by α = 30 °. When such a mathematical construction method is applied, the angle α in the apparatus within the scope of the present invention takes a value of less than 45 ° (but other methods can be applied besides this, for example, curvature. It is also possible to make the radius depend on the Z value, and it is also possible to make the shape of the corner slightly deviate from a perfect circle). When the angle formed by the X axis and the line intersecting with the center point 34 and the line 36 is less than 45 °, particularly about 30 °, the distance between the outer periphery in the X direction and the line 36 can be reduced. . Therefore, although the distance in the Y direction increases, the line deflection coil can be brought closer to the electron beam, and the power required for deflection can be reduced.

4 shows an aspect ratio A (percentage display, that is, 100) of the cross section of the cone according to the Z value in the example of FIG. 3 (in mm display, Z = 0 corresponds to the Z value of the deflection surface 11 in FIG. 1). % Corresponds to an aspect ratio of 1) and an angle θ _max (frequency display). As shown here, the aspect ratio of the cone section cross-section changes from a value less than 1 to 1 in the portion I, and changes from 1 to a value greater than 1 in the portion II. The angle θ _max changes from an angle larger than 45 degrees (about 90 degrees in this embodiment) to an angle smaller than 45 degrees. In FIG. 4, part I and part II are shown, and the boundary between these parts is indicated by vertical lines. This boundary is preferably located in the vicinity of the deflection surface (within a range of 3 cm before and after the deflection surface).

  FIG. 5 shows the aspect ratio of the cone section according to the Z value at different angles α. Here, Z = 0 corresponds to the deflection surface, a negative value of Z represents a position closer to the neck, and a positive value of Z represents a position closer to the screen. In each of the embodiments shown here, the aspect ratio (X / Y ratio) takes a value smaller than 1 in the vicinity of the cervical portion (part I), and as the Z value rises from here, that is, on the screen side. Since the aspect ratio changes to a value of 1 or more as it approaches (Part II), these examples are considered to be within the scope of the present invention. Preferably, however, the minimum aspect ratio in portion I is in the range of 0.70 to 0.90, i.e. the angle α is preferably 15-30 degrees in the figure. This is because if the minimum value of the aspect ratio is too small, it is inconvenient because the design of the deflection system and the external shape of the cone portion must be changed relatively significantly, and the aspect ratio is close to 1. This effect cannot be obtained sufficiently. Preferably, the boundary between the portion I and the portion II is located in the vicinity of the deflection surface, and specifically, within the range of about 30 mm before and after the deflection surface.

  The aspect ratio according to the vertical position (Z-axis) shown in the above-described embodiment is when the inline plane is oriented parallel to the long axis of the display screen (generally the axis extending in the horizontal direction). This is an example. This orientation of the inline surface with respect to the screen is called normal scanning. The CRT having the above-described configuration can minimize the energy required for deflecting the electron beam with respect to the screen.

  6 and 7 show a CRT configuration in which the inline plane is oriented parallel to the short axis of the screen (generally the vertical axis).

  FIG. 6 shows a case where an inline plane corresponding to a red beam deflected to a corner of the screen (an electron beam deflected to irradiate a red fluorescent element on the screen) is oriented parallel to the short axis of the screen. The aspect ratio A corresponding to the Z value (in mm) of the 32 ″, 16: 9, 105 ° deflection tube is shown in the figure. The vertical line shown in this figure indicates the Z position corresponding to an aspect ratio of 1. This is located under the deflection system.

  In the Z value (corresponding to the portion I) on the left side of the vertical line, the aspect ratio A is smaller than 1 and can be a value of 0.2 or less. On the other hand, the aspect ratio A is 1 or more at the Z value (part II) on the right side of the vertical line. By applying such a longitudinal profile, it is possible to realize a CRT configuration that is suitable for minimizing the required deflection energy.

  FIG. 7 shows the aspect ratio A according to the Z value (in mm) of the 32 ″, 16: 9, 120 ° deflection tube when the inline plane is oriented parallel to the short axis of the screen. The vertical line shown in the figure indicates the Z position corresponding to an aspect ratio of 1. In the Z value (corresponding to the part I) on the left side of this vertical line, the aspect ratio A is smaller than 1, and on the right side of this vertical line. For some Z values (Part II), the aspect ratio A is greater than 1. By applying such a longitudinal profile, it is possible to realize a CRT configuration suitable for minimizing the required deflection energy. It becomes.

  In addition, this invention is not limited to the above-mentioned Example, It is possible to envisage various modifications and changes from these Examples, and these are also included in the scope of the present invention.

  In short, the present invention is characterized by the following configuration.

  In other words, the image display device according to the present invention comprises a cathode ray tube 1 having an extended display screen 8 and a deflection system 9 for deflecting an electron beam. The display screen 8 is substantially rectangular and has a major axis and a minor axis. The cathode ray tube 1 includes a neck portion and a cone portion disposed between the neck portion and the display screen. The cone portion has an aspect ratio of 1 or less (ratio between the X dimension and the Y dimension) in the vicinity of the neck portion, and this aspect ratio approaches the display screen as it moves away from the neck portion. As it is done, it changes to a value greater than 1.

  In addition, this invention is characterized by each novelty element currently disclosed by this application, and these combination. Reference numerals appearing in the claims do not limit the scope of the invention. In addition, the expression “comprising” used in the claims is not intended to be used as a term for excluding the existence of other components than the components recited in the claims. Further, the constituent elements recited in the claims may be singular or plural unless otherwise specified. Further, the means for generating three in-line electron beams can be constituted by, for example, an electron gun or the like. In this case, three electron beams can be obtained by a common electrode (general configuration), or 3 One electron beam may be generated by three separate electron guns. However, it is of course possible to apply means other than the general configuration described above to generate the electron beam.

It is sectional drawing of the image display apparatus by one Embodiment of this invention. It is sectional drawing of a display window. It is a figure which shows the outer periphery of the cone part of CRT of the image display apparatus by one Example of this invention. It is a graph which shows the aspect-ratio according to Z value in case an inline surface is orientated in parallel with the long axis of a display screen. It is a graph which shows the aspect-ratio according to Z value in each of several Example of this invention in case an inline surface is orientated in parallel with respect to the long axis of a display screen. It is a graph which shows the aspect-ratio A according to the Z value of a 32 ", 16: 9, 105 degree deflection tube in case an in-line surface is orientated in parallel with respect to the short axis of a display screen. The aspect ratio A corresponding to the Z value of the 32 ″, 16: 9, 120 ° deflection tube when the inline plane is oriented parallel to the short axis of the display screen is shown. The vertical line shown in FIG. Indicates a Z position corresponding to an aspect ratio of 1.

Claims (3)

A cathode ray tube having an elongated display screen having a major axis and a minor axis, a cone part, and a neck part comprising means for generating three in-line electron beams;
A deflection system that is mounted on the cone portion and generates an electromagnetic field for deflecting an electron beam with respect to the screen, and is configured so that a line scanning direction is parallel to a long axis of the display screen. An image display device comprising:
The outer peripheral cross section of the cone portion has a first cross section having a major axis and a minor axis that are located in the vicinity of the neck portion and intersect each other, and the minor axis of the first section is the length of the display screen. It is configured to be parallel to the axis (aspect ratio <1), and the outer peripheral cross section of the cone portion is further located at a location away from the neck portion and has a major axis and a minor axis intersecting each other An image display device comprising: a second cross section, wherein a short axis of the second cross section is configured to be parallel to a short axis of the display screen (aspect ratio ≧ 1).   The three in-line electron beams are positioned in an in-line plane, the in-line plane is parallel to the long axis of the display screen, and the first cross-section portion is in the direction parallel to the long axis of the display screen. The minimum value of the aspect ratio between the outer peripheral dimension of the cone part and the outer peripheral dimension of the cone part in the direction perpendicular to the major axis of the display screen is in the range of 0.60 to 0.95, preferably 0.8. 2. The image display device according to claim 1, wherein the image display device is in a range of 70 to 0.90.   The three in-line electron beams are positioned in an in-line plane, and the in-line plane is parallel to a short axis of the display screen, and the first cross-sectional portion is in the direction parallel to the long axis of the display screen. The minimum value of the aspect ratio between the outer peripheral dimension of the cone part and the outer peripheral dimension of the cone part in the direction perpendicular to the major axis of the display screen is in the range of 0.20 to 0.95, preferably 2. The image display device according to claim 1, wherein the image display device is in a range of 70 to 0.90.

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