JPH0728678Y2 - Hot cathode device for cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a hot cathode device for a cathode ray tube which is provided in a cathode ray tube used in various electronic devices and emits an electron flow toward an anode.

2. Description of the Related Art In a conventional hot cathode device for a cathode ray tube, a bottom surface of a spacer provided between an upper surface of an insulating substrate for supporting a cathode sleeve and a first grid that encloses the insulating substrate and the cathode sleeve covers the entire surface. Are in contact.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional cathode device for a cathode ray tube, since the upper surface of the insulating substrate and the bottom surface of the spacer are in surface contact over the entire surface as described above, heat of the insulating substrate is transferred to the spacer. It is easy and moreover it is transmitted to the first grid, where a large amount of heat is dissipated. The purpose of this invention is to reduce the heat transfer from the upper surface of the insulating substrate to the spacer, save power consumption, and shorten the time from turning on the power until the cathode reaches the temperature required for stable operation. That is.

Means for Solving the Problems This invention which achieves the above-mentioned object will be described. It is a cathode sleeve 8 having a heater 9 for heating the cathode built therein and having a thermoelectron emitting surface 4 at its tip; formed in a circular shape. Is
Insulating substrate 1 supporting the cathode sleeve 8 in the central portion 1a; First grid 5 including the insulating substrate 1 and the cathode sleeve 8; The surface 1b of the insulating substrate 1 on the thermoelectron emission surface 4 side
In the above, except for the outer peripheral surface 2, a concave portion 1c formed by cutting out in a concave shape; the central portion 1a formed by the concave portion 1c and the surface 1d of the insulating substrate 1 opposite to the thermoelectron emitting surface 4;
A hot cathode for a cathode ray tube comprising a spacer 6 provided between the outer peripheral surface 2 and the first grid 5; and a plurality of notched recessed portions 3 formed in the outer peripheral surface 2 corresponding to the spacer 6. It is a device.

Action The heat of the cathode sleeve 8 heated by the heater 9 for heating the cathode is transferred to the insulating substrate 1 supporting it and heats it, and the heat of the heated insulating substrate 1 comes into contact with the outer peripheral surface 2 thereof. Is transmitted to the existing spacers 6, is further transmitted to the first grid 5 that is in contact with the spacers 6, and is diffused to the outside from the first grids 5.

At this time, heat conduction between the outer peripheral surface 2 of the insulating substrate 1 and the spacer 6 is hindered by the plurality of notch recesses 3 provided therebetween, so that the heat transmitted from the cathode sleeve 8 to the insulating substrate 1 is Remarkably lower than the conventional one. Further, since the central portion 1a of the insulating substrate 1 which is in contact with the cathode sleeve 8 is thinly formed by the concave portion 1c formed excluding the outer peripheral surface 2, the heat transferred from the cathode sleeve 8 to the insulating substrate 1 can be reduced. it can.

Further, the central portion 1a of the insulating substrate 1 which is in contact with the cathode sleeve 8 is a recess with the surface 1d of the insulating substrate 1 opposite to the thermionic emission surface 4.
Between the central portion 1a and the outer peripheral surface 2 which are in contact with the cathode sleeve 8 by forming the outer peripheral surface 2 of the surface 1b on the thermoelectron emission surface 4 side which is formed by 1c and the spacer 6. Can be formed longer, which also reduces the heat transferred from the cathode sleeve 8 to the spacer 6.

As described above, the device of the present invention has the above-mentioned three effects overlapping, and thereby the temperature of the cathode sleeve 8 can be raised in a short time.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is an external perspective view of a hot cathode device according to the present invention. 1 is an insulating substrate, 2 is an outer peripheral surface on the insulating substrate 1, which is in contact with a spacer 6, and 3 is a cutout provided on the outer peripheral surface 2 on the insulating substrate 1. Notch recesses 4 are thermoelectron emission surfaces, and 12a, 12b, and 12c are circular stepped grooves provided on the insulating substrate 1 to form the recesses 1c.

Reference numeral 8 denotes a cathode sleeve that penetrates the central portion of the insulating substrate 1 and is fixed to the insulating substrate 1, and has an electron emission surface 4 at the tip. 9 is a heater for heating the cathode sleeve.

In FIG. 2, 5 is a first grid, 6 is a spacer for maintaining the distance between the insulating substrate 1 and the first grid 5, and 7 is a housing for fixing the insulating substrate 1 and the spacer 6 in the first grid 5. It is a retainer. 3 is an external perspective view of the first grid 5, FIG. 4 is an external perspective view of the spacer 6, and FIG. 5 is an external perspective view of the retainer 7.

According to the configuration of this embodiment, the contact area with the spacer 6 is reduced by providing the notched concave portion 3 on the outer peripheral surface 2 that contacts the spacer 6 on the insulating substrate 1, and the heat of the cathode sleeve 8 is removed from the insulating substrate. It is possible to reduce the loss and dissipation from the spacer 6 to the outside via the heat transfer path such as the first grid 5 via the heat transfer path of the first grid 5.

Further, since the central portion 1a of the insulating substrate 1 is formed thin, heat transferred from the cathode sleeve 8 to the insulating substrate 1 can be reduced.

Further, the central portion 1a of the insulating substrate 1 which is in contact with the cathode sleeve 8 is formed by the surface 1d on the opposite side of the thermionic emission surface 4 and the concave portion 1c,
The portion contacting the spacer 6 is the surface 1b on the thermionic emission surface 4 side.
Since the outer peripheral surface 2 is bonded to the outer peripheral surface 2, the distance between the central portion 1a and the outer peripheral surface 2 can be increased, and heat generated from the cathode sleeve 8 to the spacer 6 can be reduced. .

Effect of the Invention This invention is constructed as described above, and the outer peripheral surface 2 of the insulating substrate 1 supporting the cathode sleeve 8 is in contact with the spacer 6.
In addition, by forming the plurality of cutout recesses 3, the heat of the cathode sleeve 8 can be reduced from being transferred to the spacer 6 via the insulating substrate 1.

Further, since the central portion 1a of the insulating substrate 1 which is in contact with the cathode sleeve 8 is thinly formed by the concave portion 1c formed excluding the outer peripheral surface 2, the contact area is reduced and the heat transferred from the cathode sleeve 8 to the insulating substrate 1 is reduced. Can be reduced.

Further, the central portion 1a of the insulating substrate 1 which is in contact with the cathode sleeve 8 is a recess with the surface 1d of the insulating substrate 1 opposite to the thermionic emission surface 4.
Between the central portion 1a and the outer peripheral surface 2 which are in contact with the cathode sleeve 8 by forming the outer peripheral surface 2 of the surface 1b on the thermoelectron emission surface 4 side which is formed by 1c and the spacer 6. Can be formed longer, which also reduces the heat transferred from the cathode sleeve 8 to the spacer 6.

As described above, the device of the present invention can operate the above-mentioned three operations in combination, and thus the cathode sleeve 8 can be operated.
The temperature can be raised in a short time.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, a perspective view of a part of a hot cathode device, FIG. 2 is a sectional view of the same hot cathode device, FIG. 3 is a perspective view of a part of the same device, and FIG. FIG. 5 is a perspective view of another portion of the same device, and FIG. 5 is a perspective view of yet another portion of the same device. 1 ... Insulating substrate 1a ... Central part 1b ... Surface on the side of the thermoelectron emission surface 1c ... Recess 1d ... Surface opposite to the thermionic emission surface 2 ... Outer peripheral surface 3 ... Recess 4 ... Heat Electron emitting surface 5 ... First grid 6 ... Spacer 8 ... Cathode sleeve 9 ... Cathode heating heater

Claims (1)

[Scope of utility model registration request] 1. A cathode sleeve 8 having a built-in heater 9 for heating the cathode and having a thermionic emission surface 4 at its tip; an insulating substrate formed in a circular shape and supporting the cathode sleeve 8 at a central portion 1a. 1; a first grid 5 including the insulating substrate 1 and the cathode sleeve 8; the thermionic emission surface 4 of the insulating substrate 1
On the surface 1b on the side, except the outer peripheral surface 2, a concave portion 1c formed by cutting out in a concave shape; the concave portion 1c and the surface 1d of the insulating substrate 1 opposite to the thermoelectron emitting surface 4 It is characterized by comprising a central portion 1a; a spacer 6 provided between the outer peripheral surface 2 and the first grid 5; a plurality of notched concave portions 3 formed in the outer peripheral surface 2 corresponding to the spacer 6. Hot cathode device for cathode ray tubes.