TWI253668B - CRT device with improved resolution - Google Patents

Abstract

A CRT device with an electron gun provided therein includes control means for controlling voltages applied to a cathode and a control electrode constituting the electron gun. The control means exerts control on each electrode voltage so that the difference between the cutoff voltage of the cathode and the voltage of the control electrode is greater when the luminance level of a luminance signal separated from picture signal is higher, thereby minimizing a spot diameter.

Description

1253668 A7 —-------- B7 V. INSTRUCTIONS~~~~~" — BACKGROUND OF THE INVENTION U) Technical scope of the invention This is related to, for example, a CRT device used in a computer and television assembly. And, in particular, a technique for improving resolution. (2) Description of Related Art The CRT device used in a computer monitor and television assembly grabs an electron beam from an electron on a disc-quality screen where the illuminating light is emitted to display an image. When the spot of the electron beam that causes the light of the phosphorescent screen to emit light (hereinafter referred to as "spot diameter," in the text) is small, the resolution is higher. Fig. 1 is a vertical cross-sectional view, The structure of a typical electronic grab is shown. In Fig. 1, the electron stealing system is constructed by a cathode 10, a control electrode u, an accelerating electrode 12, a focusing electrode 13, and a final accelerating electrode 14. The electrons of the radiation are accelerated by the accelerating electrode 12 toward a phosphorescent screen 15. The focusing electrode 13 and the final accelerating electrode 丨4 together produce an electrostatic lens (hereinafter referred to as a ''master lens, sir) 16 to introduce The focus of the electron beam is concentrated on the phosphor screen 15. Typically, this spot is directly controlled by the diameter of the electron beam within the main lens (hereinafter referred to as ''beam diameter, suffixed'). Producing a minimum spot of light is called an optimum beam diameter. This optimum beam diameter depends on a brightness signal, which is a current flowing through the cathode (hereinafter referred to as " Beam current, in other words, Ia. Here, the well-known person is that if an electron grab is designed, when the beam current la is large, that is, when the brightness is high, it becomes the most paper scale in the beam diameter. The Chinese National Standard (CNS) Α 4 Specifications (210X297 mm) 4 (Please read the notes on the back and fill out this page) Order! 253668 A7 -———— _- B7 ___ V. Invention description (2) Good, when the beam current is small Such electron capture does not produce the optimum beam diameter. However, conversely, if the electron % is designed to be optimal in beam diameter when the beam current is small, the beam diameter produced when the beam current is large is in the absence. To raise the above problem, when the beam current is large, the conventional electron grab is designed to be optimal in beam diameter when the beam current is large, so the beam diameter tends to be large. However, when the beam current is small, the beam diameter still falls in the lack of light, which means that when the brightness of an image is low, the resolution becomes low. As a result, for example, 'a dimming and a small figure may not be displayed in detail. Another conventional electronic rush is disclosed in Japanese Unexamined Patent Publication No. Hei 7 (1995)-085812, which is provided with an auxiliary electrode disposed between an accelerating electrode and a focusing electrode. The auxiliary electrode is applied with a voltage adjusted by the illuminance signal so as to change the intensity (convergence) of the prefocus lens. As a result, this beam diameter is controlled by the method of degrading the spot diameter. However, in order to achieve this result, a high voltage of several hundred to several thousand volts is required to be applied to this auxiliary voltage. Therefore, in order to allow the intensity of the pre-focusing lens to change in one of the modes in which the image is displayed at a high resolution within a very large and often different brightness, the electronic rush is required to have an amplifier circuit having a variation of the high voltage. In the case of high speed (several MHz to tens of MHz), this will be completely impractical. Summary of the invention

The present invention has been developed with the above problems in mind, and has a CRT paper size applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm).

V (Please read the note on the back and fill out this page), ^τ— 1253668 A7 ----- —_ B7_ V. Invention Description T—) — One "One-Β Device to display an image high Resolution without regard to the purpose of brightness. To achieve the above object, a CRT device of the present invention comprises: an electron grabbing-cathode and a control electrode; and a spot diameter control device for varying the cutoff voltage of the cathode according to a luminance signal and applying the voltage to the control electrode The difference between the spots is controlled by the difference in diameter. With this configuration, the intensity of the cathode lens varies depending on the brightness between the off-voltage of the control cathode and the voltage of the control electrode. When the intensity of the cathode lens changes, the intersection is displaced, and as a result, the spot diameter is controlled, and the resolution of the CRT device is improved. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, advantages and features of the present invention will become more apparent from In the drawings: Fig. 1 is a vertical cross-sectional view schematically showing a typical electronic grabbing structure according to one of the prior art techniques; and Fig. 2 is a view showing a vertical division along the axis 2 of the tube according to the first specific An example of a CRT device; FIG. 3 is an external oblique view showing the electronic smash 20' according to the first specific example. The focus electrode 2〇3 and the final accelerating electrode 204 are partially broken apart to display other components; Figure 1 is a view showing the electronic slap 20 divided vertically along the central axis of the electrode 2〇〇R; Fig. 5 is an explanatory block diagram showing the circuit 30 for controlling the accelerating electrode voltage Vg2 Structure and function; 6 (Please read the note on the back and fill in this page) This paper scale applies to China National Standard (CNS) A4 specification (210X297 public 1253668 V. Invention description (4) Figure 6 is a graph showing The mussel is not applied to the voltage Vg2 of the accelerating electrode of the CRT device 2 and the relationship between the spotting of the spot which is generated by the current flowing through the falling pole or the beam current la; Explanatory block , showing the structure and function of the accelerating electrode voltage control unit 301; Fig. 8 is a view showing a configuration of a relationship between the brightness signal and the control signal; FIG. 9 is a flow chart, and the display is included in Accelerating the operation of the CPU 3020 in the electrode voltage control unit 302; Fig. 10 is a view showing the electrons robbed 20 along the central axis of the electrode 2, in a form to display the entire electron grab. The final accelerating electrode 310 and the main lens 214 are included; Fig. 11 is a view showing the relationship between the current la of the cRT device 2 of the first specific example and the voltage applied to each electrode, together with an early The relationship between the current Ia of the same type of CRT device and the voltage applied to each electrode; Fig. 12 is a graph showing the relationship between the beam diameter and the spot diameter based on the different beam currents; A graph showing the diameter of the spot produced by the same crt device 2 and an early art CRT device at the center of their respective screens when different beam currents are applied to each CRT device. Figure 14 is an external oblique view showing a single accelerating electrode for an electron gun consisting of all three color KGBs, with the focusing electrode and other electrode systems partially broken apart to show other components; Standard (CNS) A4 specification (210X297 mm) --------• Loading:: (Please read the note on the back and fill out this page), OK — 1253668 A7 Γ" Β7 V. Invention system (5 ) ~~'' '- 帛15 diagram-graph showing the cathode electrical age k 'cutoff voltage Vkc, control electrode voltage Vgl, and accelerating electrode voltage Vg2 based on beam current la; Fig. 16 is a squint The figure shows a dynamic type of electronic grab; a diagram-interpret block diagram showing the structure and function of a control circuit for controlling a second embodiment of the accelerating electrode voltage Vg2; FIG. 18 is a view showing According to the operation characteristic of the electronic rush included in the CRT device according to the second specific example, the cathode voltage ¥, the cutoff voltage Vkc, the control voltage Vgi, and the acceleration are displayed by the beam current la. Electrode 19 is an external oblique view showing the electronic smashing structure according to the third specific example; f 20 is an explanatory block diagram showing the application of the heart control to the voltage of the control electrode 231R-231B The structure and function of the control circuit; Fig. 21 is a view showing the operation characteristics of the electronic grab 2b, the cathode voltage Vk which is based on the beam current Ia, the cutoff voltage Vkc, the control electrode voltage Vgl And the change in the accelerating electrode voltage Vg2; Fig. 22 is a graph obtained by the variable conversion of the graph shown in Fig. 21, and showing the accelerating electrode Vg2 and the control electrode based on the beam current ^ The difference between the voltage vgi (Vg2-Vgl), the difference between the cutoff voltage vu and the control electrode voltage Vgi (Vkc - Vgl), and the difference between the cathode voltage vk and the control electrode voltage Vgl (Vk - Vgl); Figure 23 is an external oblique view showing the structure of the electronic grab according to the fourth specific example; the paper scale is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) (please read the note on the back and fill in this page) • order BRIEF DESCRIPTION OF THE DRAWINGS (6) FIG. 24 is an explanatory block diagram showing the configuration and function of a control circuit for controlling a voltage applied to the control electrode 23 1R-23 1B and applied to the acceleration electrode 242R-242B; and 25th The figure shows a view of the operation characteristics of the electronic grab 2c, and displays the cathode electric-vk, the cutoff voltage Vkc, and the change of the control electrode voltage and the accelerating electrode voltage in accordance with the beam current Ia. DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The present specification is provided by way of example only with reference to the accompanying drawings. (1) First preferred embodiment Fig. 2 is a view showing a vertical division of the CRT device according to the first specific example along the axis of the tube. In Fig. 2, a CRT unit 2 is constructed of a glass envelope which is joined by a front panel 22 and a funnel 25. The inner surface of the neck portion 25a of the funnel 25 is arranged in a line of internal type electrons. Here, the screen size is 76 cm and the angle of refraction is 1〇6. . Each of the three colored phosphors, i.e., red, green, and blue, is applied to the inner surface of the uranium panel 22 to form a disc light screen 24. The electron beam 21 radiated from the electrons is refracted by a refractive yoke 26 which is externally disposed on the funnel 25 and separated into the respective colors by a shadow mask 23, and then the web is separated. The phosphor screen 24 is illuminated as such to cause phosphorescence. (2) Structure of the electronic grab 20 Fig. 3 is an external oblique view showing the electronic grab according to this specific example. In this figure, the focusing electrode 203 and a final accelerating electrode 2〇4 are 1253668 A7 B7. The invention description (7) is broken to show other members. As illustrated in Figure 3, the electronic grab 20 is constructed with the following components: cathodes 200R, 200G, and 200B, respectively, corresponding to color RGB; control electrode 201; acceleration electrodes 202R, 202G, and 202B, respectively The ground corresponds to color RGB; the focusing electrode 203; and the final accelerating electrode 204. The cathodes 200R, 200G and 200B are arranged in an in-line row. Fig. 4 is a view showing the electron gun 20 vertically divided along the central axis of the cathode 200R. It is to be noted that the cross-sectional views taken along the central axes of the cathodes 200G and 200B are similar to those of Fig. 4, and thus the description is provided as follows for showing a vertical cross section taken along the central axis of the cathode 200R as a demonstration. Now, as shown in Fig. 4, the cathode 200R and the control electrode 201 together produce a cathode lens 210, and the accelerating electrode 202R and the focusing electrode 203 together produce a pre-focusing lens 212. Further, although not illustrated in the drawings, the focus electrode 203 and the final accelerating electrode 204 together produce a main lens. The electron beam 213 radiated from the cathode 200R is transmitted through the cathode lens 210 to be focused on the intersection 211, and is radiated toward the pre-focus lens 212 from a predetermined divergence angle therefrom. Subsequently, pre-focusing is performed via pre-focusing lens 212, which is directed by the main lens to focus to produce a spot of light on phosphor screen 24. Here, the control electrode 20 1 has a thickness of 0.06 mm and has a diameter of 0.5 mm each. Each of the force sigma electrodes 202R-202B is 0.55 mm thick and has a 0.5 mm diameter hole. The focusing electrode 203 is 0.35mm thick and is facing the accelerating power 10. (Please read the back of the note first and then fill in this page.) The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 1253668 A7 B7 V. Invention description ( 8) One of the poles 202K-202B and has a 0.9mm diameter hole. The distance from the cathode 200R-200B to the control electrode 201 is uniformly 0.07 mm. The distance from the control electrode 201 to the accelerating electrode 202R-202B is uniformly 0.22 mm. Further, the distance from the accelerating electrode 202R-202B to the focusing electrode 203 is uniformly 0.7 mm. The voltages applied to the control electrode 201, the focus electrode 203, and the final accelerating electrode 204 are normally at 0 V, about 6,800 V, and about 32 kV, respectively. On the other hand, the voltages applied to the cathodes 200R-200B and the accelerating electrodes 202R-202B are adjusted in accordance with the luminance signals. (3) Structure of Circuit for Controlling Accelerating Electrode Voltage Vg2 Next, the description is provided for a circuit for controlling one of voltages applied to the above-described accelerating electrodes 202R-202B. Figure 5 is an explanatory block diagram showing the construction and function of a circuit for controlling the accelerating electrode voltage Vg2. In Fig. 5, a control circuit unit 30 is constructed by a YC separation unit 300, a signal processing unit 301, an acceleration electrode voltage control unit 302, and amplifiers 303 and 304. When the image signal is supplied to the control circuit 30, the YC separation unit 300 separates the image signal into the luminance signal (Y) and the chrominance signal (C). When the luminance signal and the chrominance signal are transmitted from the YC separation unit 300, the signal processing unit 301 performs various processes such as image quality adjustment, contrast control, retracement space, and the like. Thereafter, the signal processing unit 301 outputs to the amplifier 303 to correspond to the main color signals (R), (G), and (B) of each of the three colors RGB, and outputs to the accelerating electrode voltage control unit 302 to be equivalent to each. One or three color RGB luminance signals (R) - (B). 11 (Please read the note on the back and fill out this page) This paper scale applies to China National Standard (CNS) A4 specification (210X297 mm) 1253668 V. Invention description (9) This accelerating electrode voltage control unit 3〇2 self-signal The processing unit 3〇 receives the shell degree & number (R)-(B)' and outputs a control signal (RMB) to the amplifier 3〇4 to control each voltage applied to the accelerating electrodes 2〇2R_2〇2B. This control ultimately works to minimize the spot diameter equivalent to each of the three colors. This amplifier 303 receives the main color signal (RHB) and amplifies the received signal for output to the equivalent cathode 20 〇 R 2 〇〇 B. Amplifier 3〇4 receives control #唬(R)-(B) ' and amplifies the received signal to apply voltage to equivalent accelerating electrodes 202R-202B. (4) Operation of Accelerating Electrode Voltage Control Unit 3〇2 Now, the explanation is further provided in detail for the operation of the accelerating electrode voltage control unit 3〇2. The accelerating electrode voltage control unit 3 〇 2 varies the voltage applied to the accelerating electrodes 202R-202B in accordance with the luminance signal so as to minimize the spot diameter. The figure is a graph showing the relationship between the voltage Vg2 applied to the accelerating electrode of the CRT device 2 and the various values of the current flowing through the cathode or the spot diameter of the beam current la. As shown in Fig. 6, the accelerating electrode voltage Vg2 and the spot diameter depict a separate curve, and each curve has an accelerating electrode voltage Vg2 at which the spot diameter is the smallest. For example, when the beam current Ia is 3 〇 mA, the spot diameter becomes minimum 'that is about 1.9 mm, and has an accelerating electrode current vg2 of about 370 V. When the beam current la is about 0.5 mA, the spot The diameter becomes minimum, which is about 0.9 mm, and has an accelerating electrode voltage Vg2 of about 250V. A paper scale applies to China National Standard (CNS) A4 specification (210X297 mm) 1253668 A7 B7 V. Description of invention (l〇) As mentioned above, the minimum spot diameter of the accelerating electrode voltage Vg2 is determined by actual measurement. The measurement is made for each different beam current la. It should be noted that the beam current la is proportional to the brightness. The high beam current la produces a lower brightness, i.e., the minimum spot diameter of the accelerating electrode voltage Vg2 is determined for each beam current la. Therefore, the accelerating electrode control unit 302 generates a control signal in accordance with the relationship between the beam current la and the accelerating electrode voltage Vg2. Fig. 7 is a view showing the construction of the accelerating electrode voltage control unit 302. In Fig. 7, the accelerating electrode voltage control unit 302 is constructed by a single CPU 3020. In this CPU 3020, the analog input connectors AI(R), AI(G), and AI(B) receive respective luminance signals corresponding to the accelerating electrodes 202R-202B. In addition, analog output connectors AO(R), AO(G), and AO(B) outputs are used to control the respective control signals applied to the voltages of each of the accelerating electrodes 202R-202B. The CPU 3020 stores a table relating to the luminance signal and the control signal in its internal ROM. Figure 8 shows the construction of this table. As shown in Fig. 8, the table 3021 provides luminance signals (R)-(B) which are output as control signals (R)-(B) within 256 voltage levels along with their equivalent voltages. Figure 9 is a flow chart showing the operation of the CPU 3020. When receiving a luminance signal having analog input connectors AI(R), AI(G), and AI(B)(S1), the CPU 3020 performs a reference to the table 3021 with the voltage of the received luminance signal (S2) to The voltage of the control signal (S3) is measured. This CPU 3020 then outputs this control signal (R)-(B) to the voltages measured from the analog signals AO(R), AO(G) and AO(B) (S4). This paper scale applies to the Chinese National Standard (CNS) A4 specification (210X297 mm) 13 --------------•装...-.............. ....., 矸--------------#线. (Please read the notes on the back and fill out this page) 1253668 V. Inventions (11), the above method, this The accelerating electrode voltage Vg2 is manufactured in accordance with the luminance signal. By this control, the intensity (focus power) of the cathode lens changes, and the intersection is shifted forward/backward, so that the beam diameter is optimized, and thus the spot diameter is minimized. (5) Operational characteristics of the electronic grab 20 The human-specific description is provided for the operational characteristics of the electronic grab, and is concentrated on the voltage applied to each of the electrodes constituting the electron grab. Similar to Fig. 4, a first view is a view showing an electronic slam which is vertically divided along a central axis of one of the cathodes, in this case a cathode 2 can. In this figure, the entire electron capture system is shown to include a final accelerating electrode 2〇4 and a main lens 214. It should be noted that the vertical cross-sectional view taken along the central axis of the cathode 2〇〇g*2〇〇b is similar to the first drawing, and therefore, the following is perpendicular to the central axis taken along the cathode 200R. The section diagrams & descriptions are an exemplary diagram. In Fig. 10, when the accelerating electrode voltage Vg2 is raised while the brightness system remains positive, the intensity of the cathode lens 2 is increased so as to be able to bring the parent fork point closer to the cathode 2〇〇R edge. This axis z. Conversely, while the accelerating electrode voltage Vg2 is decreasing while the brightness is maintained normal, the intensity of the cathode lens 210 is lowered so that the intersection can be moved further along the axis from the cathode 200R. For example, when the intersection occurs at point 211, the electron beam 2丨3 has a diameter 2 15 5 for transmission through the main lens 214, and when the intersection occurs at a point 211', the 'electron beam 213' has a diameter 215, When passing through the main lens 214. In this way, the CRT apparatus 2 has the ability to optimize the beam diameter by controlling the Chinese National Standard (CNS) A4 specification (210 x 297 mm) by the accelerated paper size, and the invention (1) voltage Vg2. Next, the description is provided for the relationship between the beam current IA and the voltage applied to each electrode. The nth graph shows the relationship between the current Ia and the voltage applied to each electrode of this specific example, together with the relationship between the current la and the voltage applied to each electrode of the CRT device of the prior art of the same type. Here, "the CRT device of the same type of early technology, the same word and a CRTI have the same constructor of the CRT device 2 of such a specific example, except that the accelerating electrode voltage system remains normal. In Fig. 11, solid lines 400-403 show the relationship between the current beam and the voltage applied to each electrode in the CRT device 2 of this specific example. This solid line 400 represents the accelerating electrode voltage Vg2, and the solid line 4 〇1 indicates the cutoff voltage

Vkc. The crossing lines 402 and 403 represent the cathode voltage Vk and the control electrode voltage Vgl, respectively. It should be noted that the control electrode voltage, the accelerating electrode voltage, and the cathode voltage are measured by the method of transmitting the required beam current. Here, the cathode voltage is changed only while the control electrode voltage and the accelerating electrode voltage remain normal at this predetermined value, and there will be an instant at which the electron robbing no longer emits an electron beam from its cathode. In the following text, the value of the cathode voltage at this moment is referred to as the cutoff voltage. The dashed lines 400, -402, tune, and line show the relationship between the beam current la and the voltage applied to each electrode in the same type of early CRT device. This dotted line 400'402' represents the accelerating electrode voltage Vg2, the cutoff voltage, and the cathode voltage Vk, respectively. It should be noted that in both CRT devices, the control electrode voltage Vgl remains normally at the GV without being affected by the beam 1323668 A7 _________B7 5. The invention (13) current la. As described above, this brightness is "proportional to the beam current. In this particular example, the accelerating electrode voltage is increased in accordance with the beam current Ia as indicated by the solid line 400. As a result, the cathode The voltage ¥]^ changes in response to the beam current la as indicated by the solid line 4〇 2. On the other hand, in the early art, the accelerating electrode voltage remains normal as indicated by the dashed line 400'. The effect of the beam current Ia. As a result, the change of the cathode electrode Vk is represented by a broken line 4〇2. Accordingly, the difference between the cathode voltage Vk and the control electrode voltage vg l , that is, the beam current I a is subject to The possible difference between the cathode and the control electrode falls within a narrower range of variations in earlier techniques in this particular example. By the way, the intensity of the cathode lens varies according to the difference between the cathode voltage and the control electrode voltage Vgl. That is to say, in the early art, the difference between the cathode voltage Vk and the control electrode voltage Vgl varies within a wide range with respect to the beam current ia. As a result, the strength of the cathode lens greatly changes. And thus the intersection is also greatly changed. This will make it difficult to keep the beam diameter in an appropriate size without being affected by the beam current 1& variation. Conversely, in this particular example, the strength of the cathode lens is The narrower range changes, and therefore the intersection point does not shift too much. As a result, the mouth will be very easy to keep the beam diameter within about the size of the quasi-cancer. Therefore, the spot diameter has been reduced to The minimum full time is not affected by the brightness. Now, the description is further provided for Fig. 11. In general, the cutoff voltage Vkc depends on the control electrode voltage Vg 1 and the accelerating electrode voltage Vg2 _ ' u - 丨 丨 - ---- -------------- This paper scale applies to China National Standard (CNS) A4 specification (210X297 public) """

Order | (Please read the note on the back and fill in the page) 1253668 A7 B7 V. Inventions (Μ) (Please read the notes on the back and fill out this page) and test. However, in the early art, the control electrode and the accelerating electrode remained normal without being affected by changes in the beam current Ia. Therefore, the cutoff voltage Vkc is also normal without being affected by the beam current. The impact of change. In this specific example, the acceleration electrode voltage Vg2 is controlled to be higher when the beam current Ia is larger, and the cutoff voltage vkc is made higher when the beam current Ia is larger. On the other hand, the control electrode voltage Vg i is normal and is not affected by the beam current Ia. This means that in this embodiment, when the beam current Ia is large, the difference (Vkc_Vgl) between the cutoff voltage Vkc and the control electrode voltage vgi becomes larger. As can be seen from Figure 11, the cathode electric I Vk in this specific example is lower compared with the earlier techniques: the cathode voltage vk represented by the solid line 4〇2 is compared by the dotted line. 402, the indicated cathode voltage Vk is low. This narrows the range of variation between the cathode voltage Vk and the control electrode voltage Vgl. Therefore, the beam diameter is maintained in an optimum size in the above mechanism. In other words, in this specific example, the spot diameter is minimized by controlling the difference between the cutoff voltage Vkc and the control electrode voltage Vgl in accordance with the redundancy k number. (6) Relationship between spot diameter and accelerating electrode voltage Vg2 Generally, the size of one spot generated on a phosphor screen or the value of the pupil k depends on the value of the beam current Ia, and also depends on The beam goes straight. In Fig. 12, each curve shows the relationship between the straight (four) spot diameters of the beam current u. The beam diameter is referred to as the optimum beam diameter for each beam current to produce a small spot diameter. In Figure 12, each black dot is “lu, indicating the best beam with comparable beam current.

1253668 A7

diameter. In this specific example, as described above, the change in the intensity of the cathode lens in response to the change in the beam current is small, and thus the change in the beam diameter is small. Due to this, by controlling the accelerating electrode voltage Vg2, the beam diameter is adjusted to an optimum state having any beam current Ia as indicated by the crossing line 5A in Fig. 12. Accordingly, it is provided that a CRT has the ability to display an image with the best resolution regardless of brightness. An early art CRT device was designed to apply a normal constant voltage to control the electrodes, accelerating the electrodes and the like to produce an optimum beam diameter when the beam current is large. With such a CRT apparatus, when the beam current is small, the optimum beam diameter is obtained under this condition, for example, as indicated by the dashed line 50' in the figure. That is to say, when the beam current is small, the resulting beam diameter falls into a large range, so that the spot diameter cannot be minimized. (7) Experimental Results Figure 13 is a graph showing that the actual measurement of the spot diameter produced by the CRT device 2 and one of the same type of early-stage CRT devices at the center of their respective screens is applied to a different beam current system. Every CRT device. In Fig. 13, a solid line 51 indicates the relationship between the spot diameter and the beam current of the CRT apparatus of this specific example, and a broken line 52 indicates those of the same type of image forming apparatus of the prior art. Prior to measurement, the electronic rush of the early art CRT device was adjusted in such a way as to apply a voltage to each electrode such that an electron beam produced an optimum beam diameter at which the brightness was high. As shown in Figure 13, we

18 The paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) 1253668 A7 _______B7_ V. Invention description (l6) It is confirmed that the CRT device is in any beam current la, meaning that at any photometric level, The artist compares to produce a smaller spot diameter. Further, another measurement is performed on the CRT device 2 to obtain a variation range (within the range from 0A to 4 mA) in which the acceleration electrode Vg2 is changed in accordance with the change in the beam current Ia. From this measurement, it was confirmed that the acceleration electrode voltage Vg2 was varied by about 2 〇〇 v. When the variation range falls within about 200 V, the accelerating electrode voltage Vg2 is variable at a high speed (several MHz to several tens of MHz) without requiring a large-scale amplifier circuit. Therefore, this measurement produces the utility of the proven CRT device 2. (8) First Preferred Specific Modifications It is needless to say that the present invention is not limited to the specific embodiments disclosed above, and that the first specific example can be converted into several other modifications as follows. (8-1) In the first specific example, the accelerating electrode voltage Vg2 is applied separately and controlled for each of the three colors RGB. Also, the following alternatives are applicable. That is, the separate accelerating electrodes are 7' for each of the colors rgb but only %2 of the accelerating electrode voltage is varied in accordance with the luminance signal while the other two accelerating electrode voltages Vg2 remain normal. For example, only the cathode is used for an accelerating electrode of a green phosphor, and it has a high spectral brightness efficiency that makes it variable. This configuration reduces the size of the green spot, controls the size of the spot where the three beams overlap each other, and improves the resolution in the same time-time. This configuration eliminates the acceleration of the other two colors. The need for the circuit of the electrode, on the cost, this paper scale applies to the Chinese national fresh (which) A4 specifications (2) 〇 >< 297 mm): -------- ---------- ----------------------•装...: (Please read the notes on the back and fill out this page), OK | I253668 A7

It is also an advantage. (8-2) In the first specific example, a separate accelerating electrode system is provided, and the following options are applicable. Two = φ κ / 么 * Early add a fan The electrode is provided for all three of these three colors RGB. Fig. 14 is an external oblique view showing that the electrons are singularly used for all three colors of RGB - the accelerating electrode composition is similar to the portion of the electrode system which partially breaks the member. , , _ in Figure 14 'This electronic grab 2Ga has - roughly similar to the structure of the electronic grab 2 shown in Figure 3, and is controlled by a cathode 22 〇 R-220B' Electrode 221, an accelerating electrode 222, a focusing electrode 223, and a final accelerating electrode 224 are constructed. (a) In this case, for example, we prefer that the accelerating electrode voltage 控制 is controlled in accordance with the color having the highest luminance among the three colors RGB (i.e., the color has the maximum beam current la). Since the spot diameter tends to become larger and the redundancy becomes higher, the spot where the three beams of 11 (}6 overlap each other on the phosphor screen has the same spot as that produced by the beam having the highest brightness. Therefore, the diameter of the spot generated on the disc light screen is controlled by the brightness signal of the color having the highest brightness among the two colors rGB, that is, the brightness signal as the highest brightness level brightness signal. The acceleration electrode voltage Vg2 is reduced in size. As a result, the resolution of the CRT device is improved. (b) Another alternative, for example, can also be applied to control according to a green-like luminance signal. This accelerating electrode voltage is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) in the three colors of this paper. 5. In the invention specification (IS) color RGB, the green color has the highest spectral brightness efficiency color, and Therefore, it is the most advantageous point on the spectral diameter pointer. (c) Another alternative, the acceleration electrode voltage can be controlled according to the -exponential traction, which is determined by the method The weight is equivalent to the beam current Ia of each of the three colors RGB to obtain #, and then the value of this generation is added. This weighting can be implemented according to the spectral brightness efficiency of each of the three colors RGB' or another alternative factor. (8-3) In the specific example, the description is made in the case where the present invention is applied to a color CRT apparatus having three cathodes, but the present invention is not limited to this CR. The present invention can also be applied to a monochrome CRT device having a single cathode. (8-4) In the first specific example, the accelerating electrode voltage Vg2 is controlled in accordance with the intensity signal of the individual spot to light The dot diameter is minimized, but the following alternatives are applicable. For example, the accelerating electrode voltage Vg2 can be measured according to the average brightness of a screen (one frame), which is obtained by averaging the brightness of the entire screen. And the accelerating electrode voltage Vg2 may vary from frame to frame. Another alternative is that the average brightness can be obtained from one frame. For example, the average brightness can be obtained by using the predetermined time interval. The electrode voltage Vg2 can be measured in accordance with the result obtained by this method. In this way, the accelerating electrode voltage Vg2 is changed at a small frequency, which reduces the cost of a circuit for applying a voltage to each accelerating electrode. 1253668 A7 B7 V. Description of the Invention (19 (Please read the note on the back and then fill out this page) In addition, the accelerating electrode voltage Vg2 can be determined according to the following method of selecting the average brightness. These selective methods include the use of - low pass filter, wave borrower The signal obtained by processing the luminance signal and the signal obtained by detecting the harmonic value of the luminance signal. (8-5) In the first specific example, the accelerating electrode voltage Vg2 is independent of the value of the beam current la Externally controlled so that the spot of the beam is optimally sized and thus the spot is kept to a minimum. However, the following options are also applicable. For example, in the case where the beam current la may take a value from the range of 〇 mAs 4 mA, the accelerating electrode voltage Vg2 can be measured in accordance with the beam current Ia when the beam current Ia is within the range of 〇 mA to 4 mA. When the beam current la is within a range from 3 mA to 4 mA, the accelerating electrode voltage Vg2 can be set to a current value equivalent to 3 mA. In this way, the range in which the accelerating electrode voltage falls is reduced, which requires a lower withstand voltage for a circuit such as an amplifier for applying a voltage to each of the accelerating electrodes. As a result of the impact, both the power consumption and the manufacturing cost of the circuit are reduced. (8-6) In this first specific example, the control electrode voltage Vgl is kept normal from 0V. However, the following selection methods are also applicable. That is, the control electrode voltage Vgl can be a negative voltage. Fig. 15 is a graph showing the cathode voltage Vk, the cutoff voltage Vkc, the control electrode voltage Vg 1, and the accelerating electrode voltage Vg2 which is based on the beam current Ia. The solid lines 410 to 413 represent the accelerating electrode voltage Vg2, the cutoff voltage Vkc, and the cathode voltage Vk, respectively. The paper scale applies to the Chinese National Standard (CNS) A4 specification (210X297 mm·) 1253668 A7 ___________B7 V. Description of the invention (20^ " a ' '~^~ and control electrode voltage Vg 1. As shown in Figure 15, by maintaining the control electrode voltage Vg 1 with a normal negative value, the absolute value of the electrode voltage remains smaller than the electrode The relationship between the voltages is maintained in a similar manner as shown in Fig. 7. This will be reduced to the withstand voltage required to apply the voltage to one of the accelerating electrodes. As a result of the influence, the circuit Both power consumption and manufacturing cost are reduced. (8-7) In this specific example, both the focus electrode and the final accelerating electrode are applied with a normal voltage. However, the following alternative methods are also applicable. The present invention can be applied to a so-called dynamic type electronic grab in which the voltage applied to the focusing electrode varies in accordance with the angle of refraction of the electron beam. Fig. 16 is an external oblique view showing the dynamic As shown in Fig. 16, a dynamic type electronic smashing system is provided with a cathode 600R-600G arranged in line, a control electrode 601, an acceleration electrode 6〇2, a first focusing electrode 6031, and a second The focusing electrode 6〇32, and the final accelerating electrode 604 are constructed. The first focusing electrode 603.1 and the final accelerating electrode 604 are respectively applied with normal voltages from the terminals 603T and 604T. This second focusing electrode 6032 is applied thereto. The vertical refraction of the electron beam changes the voltage of the synchronism so that the focus can be adjusted. By applying the invention, the electron spot is reduced as described above, and the spot diameter is minimized without being affected by the brightness. In the above configuration, the accelerating electrode 60 can be provided separately for each color. The paper scale is applicable to the Chinese National Standard (CNS) A4 specification (2) 0X297 DON) _ 23 _ (Please read the back note first and then fill in this page )

I can I 1253668

DISCLOSURE OF THE INVENTION Aside from the above configuration, in the case of using a magnetic field or the like to generate a main lens, a focusing electrode and a final accelerating electrode can be omitted, that is, the electron gun can be only a cathode, a control electrode, And an accelerating electrode to construct. The invention can also be applied to such an electron gun. (8-8) The present invention can be implemented in combination with other techniques for controlling the spot diameter and the beam diameter, for example, the technique disclosed in Japanese Laid-Open Patent Publication No. I1 (1989)-032623. The crt device disclosed therein is given a smaller spot diameter when the beam current is larger. In the present invention, when the height is high, the present invention produces a light spot that is slightly smaller or otherwise large. This will result in an improved resolution of this CRT device. (8-9) In the above specific example, the CRT apparatus has been described with a screen size of 76 cm and a width of 1 〇6. The angle of refraction. However, the cRT embossing consistent with the present invention is not limited to such as described above, and the same effect is achieved by a device having a different screen size and angle of refraction as explained above. Further, the description of the size of the control electrode 201 and other members as described above is merely an example, and they may differ in size. Similarly, the voltage applied to each electrode is not limited to the specific values described above, and the same effect is achieved by the present invention, that is, the voltage is different. (9) Second Preferred Embodiment Now, the description will be provided for a CRT apparatus according to a second specific example of the present invention. The CRT device of this specific example is similar to the following (in order to read the back of the note, please fill out this page) - Paper Size Standards (CNS) A4 (21GX297 mm) 24 1253668 A7 -------____B7_ V. INSTRUCTIONS (22) β /, the structure of the CRTf of the system, but there is no, the cathode voltage Vk in the 保持 remains normal and is not affected by the beam current ^ The impact of change. The electronic robbing, which is similar to the first specific example, is incorporated in the _RT clothing of this specific example, and has the configuration shown in Fig. 3. Different from the first f example, in the first embodiment, the cathode voltage Vk changes according to the change of the beam level 1. In this example, the electrode systems constituting the electron gun are applied from The respective DC power supplied by the whole time is normal. With this configuration, each of the cathode electrical waste Vk remains normal for a full time. Further, similarly to the first specific example, the voltage Vg2 applied to each of the accelerating electrodes changes in accordance with the change in the amount of the beam current. The figure is an explanatory block diagram showing the construction and function of a control circuit for controlling one of the accelerating electrode voltages Vg2. In Fig. 17, similar to the control circuit 30 of the first specific example, a control circuit 3A is constructed by a YC separating unit 310, a signal processing unit 311, an accelerating electrode voltage control unit 312, and an amplifier 313. . As described above, each of the cathode voltages Vk remains normal in this specific example, and therefore does not need to be controlled, and therefore, there is no member corresponding to the amplifier 303 shown in Fig. 5. Similar to the first specific example, when the image signal system has been input to the control circuit 3a, the YC separating unit 31 〇 separates them into the luminance signal 丫 and the chrominance k number. Subsequently, the signal processing unit 31 performs various processes such as image quality adjustment, contrast control, and the like to convert the transmitted signal into a luminance signal (R)-(B), and input the generated signal to the acceleration electrode. Voltage—~-___ This paper scale applies to China National Standard (CNs) A4 specification (210X297 com): one "77 -- (please read the notes on the back and then compose this page), tr_ _线丨1253668 A7 B7 V. INSTRUCTION DESCRIPTION (23 Control unit 312.) - Upon receiving this redundancy (8)-(8), the accelerating electrode voltage control unit 312 voltage Vg2 is applied to each accelerating electrode and input to the amplifier 313. The control signal (R) representing the measured acceleration electrode voltage % (B) (B) when receiving the control signal (8) < B), the amplifier (1) amplifies the received signal to set each of the accelerating electrode voltages Vg2 to an ideal value. In this method, each of the accelerating electrode voltages Vg2 is finally controlled to correspond to a value corresponding to each beam current I a . Here, the accelerating electrode voltage control unit 312 may have a structure similar to that of the accelerating electrode voltage control unit which is not the example of Fig. 7. Further, the data for the table relating to one of the luminance signal and the control signal can be determined by actual measurement - as in the specific embodiment, the accelerating electrode voltage control unit 312 of this specific example is embodied. Now, Fig. 18 is a view showing the electron rush included in the cRT device according to this specific example, showing the cathode voltage Vk, the cutoff voltage Vkc, the control voltage, and the current of the beam current la as a graph. Accelerate changes in electrode voltage. In Fig. 18, solid lines 42A to 423 indicate acceleration electrode voltage Vg2, cutoff electrode voltage vkc, cathode electrode voltage Vk, and control electrode voltage Vgl, respectively. As shown in Fig. 18, the control electrode voltage vgl is maintained at 0 V for the entire time without being subjected to the beam current. The impact of change. Similarly, this cathode voltage Vk remains normal for a full time (in this case, 50V). The accelerating electrode voltage Vg2 is controlled by the accelerating electrode voltage control unit 312 to become large when the beam current Ia becomes large. This paper scale applies to China National Standard (CNS) A4 specification (21〇><297 public Chu) 26 (Please read the note on the back and fill out this page) -, 可丨_-线丨1253668 V. Invention Description (24) Under the control applied by the accelerating electrode voltage control unit 312, the cutoff voltage Vkc becomes equal to the cathode voltage Vk when the beam current is zero, and becomes larger when the beam current 1 & is larger. On the other hand, similar to the above, the control electrode voltage Vgl remains normal without being affected by the "change of the beam current. Therefore, in this specific example, as in the first specific example, when the beam current is la When large, the difference between the cutoff voltage vkc and the control electrode voltage (Vkc - Vgl) becomes larger. In accordance with this specific example, when the beam current becomes large, the control electrode voltage Vgi and the accelerating electrode voltage Vg2 The difference (Vgi_Vg2) becomes larger, and therefore, the intensity of the prefocusing lens is reduced. On the other hand, the difference (Vk_Vgi) between the cathode voltage vk and the control electrode voltage Vgl remains normal without being affected by the beam current. Therefore, the intensity of the cathode lens is also kept normal and is not affected by the change of the beam current la. It should be noted here that among the lenses produced by the electron grab, the cathode lens system mainly determines this. One of the beam diameters, while the prefocusing lens has a small influence on the beam diameter. Therefore, in this specific example, the control electrode voltage Vgl is adjusted so as to stably maintain the beam. The diameter is of a suitable size and is not affected by the amount of the beam current Ia, so that the spot diameter is kept small. Further, since the cathode voltage Vk in this specific example remains normal as described above, separately The DC power supply is sufficient to supply power to the cathodes. Therefore, it is sufficient to provide an amplifier circuit for controlling the beam current only for each of the accelerating electrodes; this is an advantage in which the electron is captured in it. The structure of the peripheral circuit is simplified. 1253668 A7 V. Description of the invention (25) The third preferred embodiment is a CRT garment according to a third specific example of the present invention. The CRT device in this specific example has a configuration substantially similar to that of the CRT device according to the first specific example. However, unlike the image device of the first specific example, the CRT device maintains the acceleration electrode voltage in this specific example. Vg2 is normally unchanged without being affected by the change of the beam current Ia, and the control electrode voltage Vgl is decreased when the beam current becomes large. The electricity included in the CRT device according to this specific example The structure is substantially similar to the electronic smashing structure included in the image device according to the first specific example. Fig. 19 is an external oblique view showing the structure of the electronic robbing 20b according to this specific example. The specific example (Fig. 3) differs in that the control electrode 201 is shared among the three colors RGB, and the three control electrodes 231R-231B are provided in this specific example (Fig. 19). Like Fig. 3, three of the accelerating electrodes 2〇2R-2〇2B are separately provided for three colors of RGB, and the electron grab in Fig. 19 includes a single accelerating electrode 232 commonly used for the three colors. In the first specific example, the voltage Vg2 202 applied to each of the accelerating electrodes is varied in accordance with the amount of the beam current Ia, and the voltage Vgl applied to the control electrode 201 is maintained at a normal value all the time without being subjected to the beam current. The impact of changes in Ia. Conversely, in this embodiment, the voltage Vg2 applied to the accelerating electrode 230 is maintained at a normal value for a full period of time without being affected by the change of the beam current Ia, and applied to each of the control electrodes 23 IK-23 1B. The voltage Vgl is controlled to be lower than the beam current 1 & Light

(Please read the precautions on the back and fill out this page) ., can | ▼ 丨 丨 1253668 A7 B7 V. Description of the invention (26 Figure 1 is an explanatory block diagram showing the application to the control electrode 231R-231B The configuration and function of one of the voltage control circuits. In Fig. 20, a control circuit 3〇b is connected by Yc* from unit 32, signal processing unit 321, a control electrode voltage control unit 323, and amplifiers 322 and 324. The YC separation unit 32 receives the image signals and separates them into a shell signal (Y) and a chrominance signal (C), and outputs a sub-signal. The k唬 processing unit 321 receives the luminance signal (γ) and the chrominance. The signal (C) is processed concurrently, such as image quality adjustment. This signal processing unit 3 12 then outputs a primary color signal (RHB) to the amplifier 322, and a luminance signal (R)-(B) to the control electrode voltage control unit 323. When the primary color signal (r)_(b) is received, the amplifier 322 applies the voltage separately to the cathode (R)-(B) corresponding to each color RGB according to the received signal. This control electrode voltage control list when receiving R)-(B) The element 323 outputs a control signal (RHB). The amplifier 324 receives and amplifies the control k number (R)-(B) to adjust the control electrode voltage Vgi to an ideal value. In the above method, the control electrode voltage V g 1 Finally, it is controlled to correspond to a value corresponding to the beam current la. Here, the control electrode voltage control unit 323, for example, may have control similar to the first specific example as shown in the example in FIG. The electrode voltage is only the structure of the unit. In addition, the data for the table of the brightness signal and the control signal can be determined by actual measurement as in the first specific example, so that the control electrode voltage can be embodied. Control unit 323. Next, the description is made for the operational characteristics of the electronic grab 20b included in the CRT apparatus according to this specific example. Fig. 21 is a view showing the electronic paper scale applicable to the Chinese National Standard (CNS) A4 specification. (210X297 mm) 29 (Please read the notes on the back and fill out this page). Installed - •, available | 1253668 Description of invention (27) Grab the operating characteristics of 20b, by means of a graph, display with beam The cathode voltage Vk' cutoff voltage Vkc, the control electrode voltage ¥, and the acceleration electrode voltage Vg2 are changed. In the 2nd figure, the solid line: 30-433 respectively represents the acceleration electrode Vg2 'cutoff voltage - cathode The voltage Vk, and the control electrode voltage vg 丨. As shown in Fig. 21, the accelerating electrode voltage Vg2 is maintained at full time in a positive phase (500 V in this specific example) without being affected by the beam current la On the other hand, the cutoff voltage Vkc, the cathode voltage, and the disturbing electrode voltage Vg1 both decrease when the beam current Ia becomes large. When the field beam current 1a is equal to zero, the cathode voltage vk and the cutoff voltage Vkc are equal to each other. Fig. 22 is a graph obtained by variable conversion of the curve shown in Fig. 21, and shows the difference between the accelerating electrode voltage vp and the control electrode voltage Vgl (Vg2_Vgl) which is based on the beam current ia, the cutoff voltage The difference between vkc and the control electrode voltage Vgl (Vkc_Vgl), and the difference between the cathode voltage vk and the control electrode voltage Vgl (Vk_Vgi). In Fig. 22, the line 430M33' indicates the difference in the Vg2-Vgl voltage and the difference in the Vk-Vgl voltage, respectively. Comparing the graph shown in Fig. 22 with the graph shown by the solid line in the second graph, it is obvious that the CRT device of this specific example is similar in terms of the control voltage ¥§1. The operational characteristics of those of the crt device of the first specific example. Accordingly, similar to the CRT device of the first specific example, the intensity of the cathode lens in the CRT device of this specific example is extremely small and is not affected by the change of the beam current la, and the diameter guided to the spot is reduced to the full time. The most paper grade applies to the Chinese National Standard (CNS) A4 specification (210X297 Gongdong) 30 (please read the note on the back and fill out this page), ^τ— ▼ Line _ 1253668 V. Invention Description (28) Small but not Affected by brightness. Further, unlike the above-described first and second specific examples, wherein the accelerating electrode voltage Vgl is changed 'in this case, in the specific example, the control voltage Vgl is transmitted in accordance with the luminance. ~ and culture. Here, the control electrode voltage is lower than the accelerating electrode voltage Vg2 at the potential electric shock 1 , and therefore, the control electrode voltage control circuit 30b is used with a lower withstand voltage. The components are specific to the actual ^. This would be an advantage in that the control electrode control circuit 30b is low in both power consumption and manufacturing cost. (11) Correction of the third preferred embodiment This third embodiment can be converted into various other modifications as follows: (11-1)

In the above description, we have shown that the control electrode is provided separately for each RGB color. However, the following alternatives are also applicable. That is, a single control electrode is provided for all three types of color gRGB. Here, for example, the control electrode can be applied in accordance with the voltage of the beam current having the maximum current amount among the beam currents flowing through each of the three cathodes. (11-2) Similar to the above (8-4), this third specific example can be corrected as follows. That is, the control electrode voltage Vgl can be varied in accordance with the average brightness of each screen. Another alternative is that the average brightness can be obtained from other ranges than one frame. Both methods reduce the production cost of the circuit, such as an amplifier, to apply a voltage to the control circuit. Further, the control electrode voltage V g 1 can be determined by averaging the shell degree in accordance with the following alternative methods. These options include the use of low-pass filters for this paper scale to apply the Chinese National Standard (CNS) A4 specification (210X297 public Chu) 1253668 A7 ---------B7__ one five, invention description (29) to deal with the party The signal obtained by the degree signal and the signal obtained by the envelope detection of the Qin value of the luminance signal. (11-3) Similar to the above (8-5), this third specific example can be modified to vary the control electrode voltage Vgl only when the beam current Ia is within a predetermined range of beam currents, and The control electrode voltage Vgg is maintained at a fixed value when the beam current "falls below the predetermined range. This method requires a lower withstand voltage for the circuit to apply the voltage to the control electrode. (11-4) Similar to the above (8-7), the third embodiment of the present invention can be applied to a dynamic type of electronic grabbing to minimize the spot diameter. At the same time, the control electrode can be used for each color. Provided separately. In addition to the electron gun having the above structure, in the case of using a magnetic field or the like to form an electron grab of one of the main lenses, a focusing electrode and a final accelerating electrode may be omitted, that is, the electronic grabbing It can be constructed using only one cathode, one control electrode, and one accelerating electrode. (12) Fourth Preferred Embodiment Next, the description is given to the CRT device according to the fourth specific example. The CRT device in this specific example is also Big The configuration is similar to that of the CRT device according to the first specific example. The image device of this specific example is different from the image device of the other specific examples, in which the control electrode voltage Vgl and the accelerating electrode voltage Vg2 are in accordance with the beam current. Ia changes at the same time. The electronic squirrel structure included in the CRT device of this specific example is substantially similar to the electronic stalker included in the CRT device of the first specific example. The paper scale applies to the Chinese national standard ((10) A4 specification (21〇χ297 公董) 32 (Please read the note on the back and fill out this page again) Factory installation _ _, 可 | . Line _ 1253668 A7

V. DESCRIPTION OF THE INVENTION (3A) Fig. 23 is an external oblique view showing that the electronic smashing structure according to this specific example is different from the first specific example (Fig. 3) in which the control electrode 2〇1 is attached to - The colors RGB are shared in the middle, but in this specific example (Fig. 23), three control electrodes 241R-241B are provided. Further, unlike the first specific example, in which the voltage vgl is applied to the control electrode 201, it remains normal without being affected by the change of the beam current, but in this specific example, all the voltages applied to the control electrode 241R-241B are The voltage applied to the accelerating electrode 242R_242B varies in accordance with the amount of current of the beam current la. Figure 24 is an explanatory block diagram showing the construction and function of a control circuit for applying voltages to the control electrodes 23 1R-23 1B and to the accelerating electrodes 242R_242B. In Fig. 24, the control circuit 3〇c is composed of a ye separating unit 330, a signal processing unit 33 1, a control electrode voltage control unit 333', an accelerating electrode voltage control unit 335, and amplifiers 332, 334 and 3 3 6 Constructed. The YC separation unit 330 receives the image signals and separates them into a luminance signal (Y) and a chrominance signal (C), and outputs the separated signals. At the reception of the luminance signal (γ) and the chrominance signal (c), the signal processing unit 331 performs processing such as image quality adjustment, and outputs a primary color signal (R)_(B) and a luminance signal (R)-( B). Upon receipt of the primary color signals (r)-(B), the amplifier 322 amplifies the received signals to apply them to the respective cathodes (R)_(B). The control electrode voltage control unit 333 receives the luminance signal (R)_(B:>, and outputs a control signal (R)-(B). The amplifier 334 amplifies the control signal (r)_(b) to apply voltage to control. Electrode. This accelerating electrode voltage control unit 335 receives

1253668 V. INSTRUCTIONS (31) This Brahman signal (R)-(B) outputs a control signal (R)_(B). Amplifier 336 amplifies control signals (R)-(B) to apply voltage to the accelerating electrodes. In the above manner, the voltage applied to the control electrode 231R_231B and the acceleration electrode 242R-242B is controlled to a value equivalent to the beam current Ia. Here, the control electrode voltage control unit 323 and the accelerating electrode voltage control unit 335 may have, for example, a configuration similar to that of the above-described control electrode voltage control unit 302. In addition, the data for the table of the brightness signal and the control signal can be determined by actual measurement as in the first specific example, so that the control electrode voltage control unit 3 3 3 and the acceleration electrode voltage control unit 335 are embodied in the future. . Next, the description will be directed to the operational characteristics of the electronic grab 20c included in the CRT apparatus according to this specific example. Figure 25 is a view showing the operational characteristics of the electronic grab 2, showing the cathode voltage Vk' cutoff voltage vkc, and the control electrode voltage Vg 1 and the accelerating electrode voltage Vg2 by a graph of the beam current; The change. In Fig. 25, solid lines 440-443 denote acceleration electrode voltage Vg2' cutoff voltage vkc, cathode electrode Vk, and control electrode voltage Vgl, respectively. As shown in Fig. 25, the control electrode voltage Vg1 drops when the beam current la becomes large, and the accelerating electrode voltage Vg2 rises when the beam current Ia becomes larger. On the above graph, a curve diagram similar to that shown in Fig. 22 is obtained by performing a variable conversion in a manner similar to that employed by the third embodiment. This means that similar to the first specific example, in this specific example, the change in the intensity of the cathode lens is small and the paper scale which is not changed by the beam current Ia is applicable to the Chinese National Standard (CNS) M specification (21〇χ297 public). PCT) (Please read the notes on the back and fill out this page), can be. - Line _ 34 1253668 A7 -----丨·ι Β7 V. Invention description (32) Influence, so the spot diameter is minimized It is not affected by brightness. (13) Modification of the fourth preferred embodiment This fourth embodiment can be converted into various other correction formulas such as those listed below. (13-1) In the above specific example, the cathode voltage Vk can be kept constant without being affected by the party beam current la, or varied in accordance with the luminance signal, so that the cathode lens can be made suitable in strength. (13-2) Similarly to the above (8-4), the control electrode voltage Vgl and the accelerating electrode voltage Vg2 in the above fourth specific example may be varied in accordance with a predetermined range such as the average luminance of a frame. As a result, the production cost of a circuit, such as an amplifier, is reduced. Further, in place of the average brightness of the predetermined range, the signal obtained by processing the luminance signal using a low pass filter can be used to vary the control electrode voltage Vg 1 and the accelerating electrode voltage Vg2. (13-3) Similarly to the above (8-5), the control electrode voltage Vgl and the accelerating electrode voltage Vg2 in the fourth specific example described above can cause the beam current to be glare. Whether it falls within a predetermined range and is fixed or changed. In this way, the circuit for controlling the control electrode voltage Vgl and the like can be made low in both power consumption and manufacturing cost. (13-4) Similar to the above (8-7), the above fourth specific example of the present invention can be applied to a dynamic electronic grab, or to a Chinese national standard without a focusing electrode and a final paper scale ( CNS) A4 specification (210X297 public Chu) 35 • Gutter. (Please read the back note and refill this page) 1253668 V. Invention description (33 Acceleration electrode electronic grab, and therefore can only be controlled by “cathode...” The electrodes, the crucible and the accelerating electrode are constructed. Each application achieves the effects of the present invention. Although the present invention is fully described by way of example with reference to the accompanying drawings, it should be understood that various changes and modifications are Therefore, unless such changes and modifications are excluded from the scope of the present invention, they should be considered as included. (Please read the notes on the back and fill out this page)

I. Line - 36 This paper scale applies to China National Standard (CNS) A4 specification (210X297 mm) 1253668 A7 B7 V. Invention description (34) Component label comparison 1... Electronic grab 203... Focus electrode 2 CRT device 204...final acceleration electrode 10...cathode 210...cathode lens 11...control electrode 211...intersection 12...acceleration electrode 212...prefocus lens 13 . .. focusing electrode 213...electron beam 14...final accelerating electrode 214...main lens 15...phosphorescent screen 215...diameter 16...electrostatic lens 220...cathode R,G,B 20...electron gun 2 21...control electrode 21...electron beam 222...acceleration electrode 22...front panel 223...focus electrode 23...shadow mask 224...final acceleration electrode 24...phosphorescent screen 231. .. control electrode 25...following 241R-241B...control electrode 25a...neck portion 242R-242B...acceleration electrode 26...refraction 30...YC separation unit 30...control circuit unit 301...Signal processing unit 60...dynamic type electronic grab 302...acceleration electrode voltage control 200R, G, B... cathode red, green, blue early 201... control electrode 303, 304... amplifier 202R, G , B... Acceleration electrode 310...YC separation unit (please read the note on the back and fill in this page first) This paper size applies to China National Standard (CNS) A4 specification (210X297 mm) 37 1253668 A7 B7 V. DESCRIPTION OF THE INVENTION (35) 3 11...Signal processing unit 4 0 3...Control electrode voltage 3 12...Acceleration electrode voltage control 400'-402'-dashed line** Early 兀410...Acceleration electrode voltage 3 13...Amplifier 411...OFF voltage 320 ...YC separation unit 412·.· Cathode voltage 321.··Signal processing unit 413...Control electrode voltage 322 '324·.·Amplifier 600R-B·.·Cathode 323···Control electrode voltage control 601...Control electrode Unit 602... Acceleration electrode 330...YC separation unit 604.··Final acceleration electrode 331...Signal processing unit 3020···Central processing unit 332 '334' 336...Amplifier 3021·.·Table 333...Control Electrode voltage control 603 1...first focus electrode unit 3032·.·second focus electrode 335···acceleration electrode voltage control Vk...cathode voltage unit Vkc...off voltage 4 0 0...force mouth far _ Electrode voltage Vgl... control voltage 401.·· Stop voltage Vg2... Accelerate electrode voltage 402···Cathode voltage I a... Beam current (please read the back note first and then fill in this page), install —, one-Τ, . National Standard (CNS) Α4 Specifications (210X297 mm) 38

Claims (1)

1253668 —-------- VI. Patent application scope A BCD 10 15 20 苐91100513 application for the application of the singer Shen 々々 ^ 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲The cathode is equivalent to a different color; and the spot diameter control means is for each color change - equivalent to the cathode cut-off voltage and applied to the control electrode by a brightness signal having the highest brightness level among the brightness signals corresponding to the three colors The difference between the voltages' is used to control the diameter of a spot. 2. The color CRT device of claim 2, wherein the spot diameter control device reduces the spot speed by performing control, and when the brightness level of the brightness signal of the highest brightness level is relatively the same, The difference between the cutoff voltage of each cathode and the voltage applied to the control electrode is large. 3. The color CRT device of claim 1, wherein the electronic rush includes an accelerating electrode, and the spot diameter control device controls the voltage applied to the accelerating electrode by a brightness signal according to a highest brightness level. The difference between the cutoff voltage of each cathode and the voltage applied to the control electrode. 4. If the color c rt device of the third paragraph of the patent scope is applied, the spot diameter control device performs control so that when the brightness level of the highest brightness level brightness signal is high, the voltage system applied to the accelerating electrode Higher. 5. The color crt device of claim 3, wherein the spot diameter control device performs control so that the voltage applied to each cathode remains normal without being affected by the brightness signal. This paper U Lake Zhongguan Group (CNS) ~ Secret '(2) (10) Jia Gong Chu Ding 39 ABCD 1253668 〃, the scope of application for patents 6. For example, the color CRT device of the patent scope of the patent, the spot diameter control is shocked, borrowed The voltage applied to the control electrode is controlled in accordance with the luminance signal of the highest 四 (4) to vary the difference between the cutoff voltage of each cathode and the voltage applied to the control electrode. 7. The color CRT device of claim 6 wherein "the spot diameter control device performs control so that when the brightness level of the highest brightness level brightness signal is higher, the voltage is applied to control: 10 15 20 8 · The color CRT device of claim 1, wherein the electronic robbing comprises an accelerating electrode, and the spot diameter control device is controlled by the highest brightness signal The voltage of the control electrode and the voltage applied to accelerate the voltage of the second electrode are varied to vary the difference between the cutoff voltage of each cathode and the voltage applied to the control electrode. 9. The color CRT device according to claim 8 of the patent application, wherein The spot diameter control device performs control so that when the brightness level of the highest brightness level brightness signal is high, the voltage applied to the control cell is lower and the voltage applied to the accelerating electrode is higher. Color CRT (cathode ray tube) device, comprising: an electron gun comprising a control electrode and three cathodes, each cathode corresponding to a different color; and spot diameter control The device controls the spot diameter by changing the difference between the off-voltage of the cathode and the voltage applied to the control electrode for each color change according to the color brightness signal. The paper size is applicable to the @国票准( CNS ) A4 specification 0X297 public!) 40 - ABCD 1253668 ~, the scope of application for patents u. For the color crt device of patent application scope 1G, the center control device, by implementing control to reduce the intercept of the direct cathode of the light spot:: When the brightness level of the ... signal is high, the difference between the voltage and the voltage applied to the control electrode is large. ' △ For example, the color crt device of the first application of the patent scope, wherein the electron % includes two Acceleration electrodes, each accelerating electrode is equivalent to each color, and 10 15 20 light", which is a direct analog control device, which changes the cutoff voltage of each cathode and controls it by controlling the voltage applied to each accelerating electrode according to a corresponding brightness signal. The difference between the voltages of the electrodes. 13. The color CRT device according to claim 12, wherein the spot diameter control device performs control so that when the brightness level of the corresponding brightness signal is high, the voltage applied to each of the accelerating electrodes is higher. . I4. The color CRT device of claim 12, wherein the spot diameter control device performs control so that the voltage applied to each cathode remains normal without being affected by a relatively bright signal. [15] The color CRT device of claim 1, wherein the control electrode is formed by three electrodes, each electrode is equivalent to each color, and the spot diameter control device is controlled by a corresponding brightness signal. The voltage applied to each control electrode, and the cutoff paper size of each cathode is changed according to the Chinese National Standard (CNS) A4 gauge (21 0X297 mm) 41 1253668 Shen Qing patent range 10 15 pressure and applied to the equivalent control electrode The difference between the voltages. : The color CRT device of the 15th item of the patent of the month of the month, wherein the spot 4 control liquid is placed and controlled, so that when the brightness level of the equivalent brightness signal is high, the voltage applied to each control electrode is compared. low. 7. The color CRT device according to claim 10, wherein the electron robbing comprises three accelerating electrodes, each accelerating electrode is equivalent to each color, and the control electrode is formed by two electrodes, each electrode being equivalent to each color And the spot diameter control device controls the voltage applied to each control electrode and the voltage applied to the corresponding acceleration electrode according to the equivalent brightness signal, and changes the cutoff voltage of each cathode and applies to the equivalent control The difference between the voltages of the electrodes. 18. The color CRT device of claim 17, wherein the spot diameter control device performs control so that when a comparable degree of shell size is higher, the control electrode is applied to each control electrode. The voltage system is lower' and the voltage applied to the equivalent accelerating electrode is higher. 0 This paper scale applies to the Chinese National Standard (CNS) A4 specification UlOX 297 mm) Gutter 42