JPH04128871A - Fluorescent display device - Google Patents

Abstract

PURPOSE:To reduce the number of outer terminals and to simplify a power supply circuit by connecting an IC to a power supply source through a diode at a chip in glass type device incorporating an IC for driving purpose connected to the different high voltage power supply sources having by numbers of anodic light emitting voltages and allowing it to operate with plural light emitting voltages. CONSTITUTION:Since the fluorescent body layer having different light emitting colors have different light emitting efficiencies, the brightness is different from each other when they are emitting light at the same voltage. Then it is neces sary to correct the balance of the brightness, by adjusting the light emitting voltages applied. Accordingly plural anodic light emitting voltages are necessary. For example this device has integrated circuits drived with 2 different high voltage power supplies. Between a power supply voltage VI of an integrated circuit I and a power supply voltage VII of an integrated circuit II there is a relation of VI > VII. VII is connected to a VI voltage with a diode 17. Hence when the current flows in the integrated circuit II, the voltage of VII is lower than that of VI by the voltage drop of the diode 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent display device, and more particularly to a so-called chip-in-glass type fluorescent display device in which an integrated circuit chip for a driving circuit is built in a vacuum envelope.

[Conventional technology]

Conventionally, this type of chip-in-glass (hereinafter referred to as CIG)
As shown in FIG. 3, the type fluorescent display device comprises a vacuum envelope made of an anode substrate 1, a spacer glass 3, a cover glass 2, and a low melting point glass (not shown) that hermetically seals the space between each of them. . An anode 6 is provided on the anode substrate 1 and covered with a phosphor layer formed in a predetermined display pattern. A mesh metal electrode 5 (hereinafter referred to as a grid electrode) is provided on the anode 6, covering the anode 6 and maintaining a predetermined interval, and furthermore, a mesh metal electrode 5 (hereinafter referred to as a grid electrode) is provided on the anode 6 and maintaining a predetermined interval. A linear cathode 4 is fixed and stretched to a filament support structure 10.

During operation, the linear can F4 is heated by electricity, and when the potential of the grid electrode 5 becomes positive with respect to the potential of the linear cathode 4, it emits thermoelectrons and becomes an electron source.

The emitted thermoelectrons impact the anode 6, which has a positive potential with respect to the potential of the linear cathode 4, causing the phosphor layer to emit light and displaying a predetermined pattern.

The driving Si integrated circuit chip 8 selectively controls the potential of the plurality of anodes 6 to be positive with respect to the potential of the linear capacitor F'4. Connection electrodes (commonly called pads) of the driving Si integrated circuit chip 8 and these anodes 6. The external terminal 7 is electrically connected. Conductor wiring 41 formed of a thin film or a thick film (
(indicated by a broken line in the figure) is connected by a thin metal wire 42.

That is, this type of fluorescent display device uses Si for driving using power and control signals supplied from the outside through the external terminal 7.
Controlled via integrated circuit 8.

As this driving Si integrated circuit chip 8, one having the configuration shown in the block diagram of FIG. 4 is widely used.

Such a driving Si integrated circuit chip 8 is connected to a single high-potential power source and controlled by a clock signal, serial data input, and other control signals. Each of the plurality of output drivers is connected to a separate anode 6 via a thin metal wire 42 and a conductor wiring 41, and controls the potential of the anode 6 according to a control signal.

Moreover, as shown in FIG. 5, such driving Si integrated circuit chips 8 are often used in multiple connections (cascade connection), and multiple driving integrated circuit chips 8 driven by a power source of the same potential are used. Since circuit chips I and It are connected to and driven by the same external terminal for power supply, in a CIG type fluorescent display device, only one external terminal for power supply is required for driving integrated circuit chips I and II. It is enough.

[Problem to be solved by the invention]

In the conventional CIG type fluorescent display device described above, there is a multicolor display in which anodes made of phosphor layers having a plurality of different emission colors are mixed in the same display device.

Usually, phosphor layers that emit light of different colors have different luminous efficiencies, and therefore, when emitted at the same potential, the luminance will be different. In such a display device, unless the balance of luminance of each emitted color is adjusted, the visibility of a particular emitted color will be significantly reduced, and therefore the function of the display device will often be degraded.

In order to prevent this function from deteriorating, it is usually necessary to adjust the emission voltage applied to the anode made of phosphor layers having different emission colors to maintain the luminance balance within an appropriate range. Therefore, in such a fluorescent display device, a plurality of anodic emission potentials are required.

Such a CIG type fluorescent display device is driven by incorporating driving integrated circuit chips connected to at least as many different high-potential power supplies as there are anode emission potentials. In this case, as shown in Figure 6, serial data input terminals 13 and 23 are required for the number of different high-potential power supplies, and the advantage of the CIG type fluorescent display device, which is that the number of leads can be reduced, is not utilized. There was a drawback.

Furthermore, from the user's side, it is necessary to prepare power supplies with different potentials, V+ and V+, which has the disadvantage of complicating the power supply circuit.

An object of the present invention is to provide a fluorescent display device with a small number of external terminals and a simple power supply circuit.

[Means to solve the problem]

The present invention includes a vacuum envelope, a linear cathode serving as an electron source disposed within the vacuum envelope, and an anode coated with a phosphor layer that emits light due to the impact of electrons from the linear cathode. a grid electrode for controlling the electron emission; an integrated circuit chip forming part of a control circuit for controlling the potential of the anode; an external terminal for supplying a power control signal to the integrated circuit chip; A fluorescent display device comprising a terminal and conductor wiring electrically connecting the integrated circuit chip,
A plurality of the integrated circuit chips are arranged, each of which is driven by a plurality of power supplies with different potentials, and a part of the conductive wiring connected to the plurality of power supplies with different potentials is a combination of a diode and a Zener diode. It is connected to the external terminal at the same potential via either one of them.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a connection diagram of a driving integrated circuit chip built into a CIG type fluorescent display device according to a first embodiment of the present invention.

In a first embodiment, as shown in FIG. 1, a CI, G type fluorescent display device has a driving integrated circuit chip driven by two different high potential power supplies.

There is the following relationship between the power supply potential ■1 of the integrated circuit chip I and the power supply potential v1 of the integrated circuit chip ■.

Vl>VI Vt is connected to the potential of vl via a diode 17. Therefore, when a power supply current flows through the integrated circuit chip H, the potential of (2) becomes lower than vl by the forward voltage drop of the diode 1γ.

The forward voltage drop of one diode with normal characteristics is 0.6
If three diodes 17 are connected in series as shown in Figure 1, ■I≠V, -0.6X 3 (V
).

In the embodiment shown in FIG. 1, there are three diodes 17, but the potential of VI can be adjusted by selecting the number according to the difference between (1) and (1).

Further, in the embodiment shown in FIG. 1, the number of integrated circuit chips is two, but the same applies to the case of three or more integrated circuit chips.

FIG. 2 is a connection diagram of a driving integrated circuit chip built into a CIG type fluorescent display device according to a second embodiment of the present invention.

In the second embodiment, as shown in FIG. 2, a CIG type fluorescent display device has a driving integrated circuit chip driven by three different high potential power supplies.

The following relationship exists between the power supply potential v1 of the integrated circuit chip I, the power supply potential ■1 of the integrated circuit chip ■, and the power supply potential ■ of the integrated circuit chip ■.

V + > VI, V 1 > V iV! ,
Vs is % Vl respectively, Zener diode 18a, 1
8b. Therefore, V, , V, each have a potential lower than 1 by the Zener voltage of the Zener diodes 18a and 18b.

Therefore, in this second embodiment, the potential of V, , V, is adjusted by the selection of the energy diodes.

In the circuit shown in the first embodiment of the present invention, ■! =18V,
The CIG type fluorescent display device with Vl=13.8V and seven diodes arranged in series operated very stably. or,
In the circuit shown in the second embodiment of the present invention, Vl=18V,
Vl = 15V, VW = 12■, Zener voltage 6V,
A CIG type fluorescent display using a 3V Zener diode also showed stable operation.

[Effects of the Invention] As explained above, the present invention provides a CIG type fluorescent display device in which a diode or a Zener diode is disposed between power supply wirings of a plurality of integrated circuit chips driven by different power supply potentials. This has the effect that it can be driven with a single externally supplied power supply potential. Therefore, the number of external terminals serving as high potential power supply terminals can be reduced to one, without impairing the advantage of the CIG type fluorescent display device, which has a small number of leads.

In addition, the present invention has the advantage that it is possible to provide the user with a fluorescent display device that operates at a plurality of light emission potentials with a single power supply potential.

[Brief explanation of drawings]

FIG. 1 is a connection diagram of a driving integrated circuit chip built into a CIG type fluorescent display device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a driving integrated circuit chip built into a CIG type fluorescent display device according to a second embodiment of the present invention. 3 is a partially cutaway perspective view of an example of a conventional CIG-type fluorescent display device, FIG. 4 is a block diagram of an example of a driving integrated circuit chip, and FIG. 5 is a diagram of a conventional CIG type fluorescent display device. A connection diagram of one example of two driving integrated circuit chips, and FIG. 6 is a connection diagram of another example of conventional two driving integrated circuit chips. 1... Anode substrate, 2... Cover glass, 3... Spacer glass, 4... Linear cand, 5... Grid electrode. , 6...
・Anode, 7... External terminal, terminal, 12, 22.
32...High potential power supply terminal, 13.23.33.
... Serial data input terminal, 14a, 14b,
24a, 24b, 34a, 34b... Control signal input terminal, 15, 25. 35... Serial data input terminal, 16a, 16b, 26a. 26 b, 36 a, 36 b...driver output terminal, 17... diode, 18a
, 18b...tsu;na diode, 41...
...Conductor wiring, 42...Metal thin wire. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] a vacuum envelope, a linear cathode serving as an electron source disposed within the vacuum envelope, an anode coated with a phosphor layer that emits light by the impact of electrons from the linear cathode, and radiation of the electrons. an integrated circuit chip constituting a part of a control circuit that controls the potential of the anode; an external terminal for supplying a power control signal to the integrated circuit chip; In a fluorescent display device equipped with conductor wiring that electrically connects circuit chips, a plurality of integrated circuit chips are arranged, each of which is driven by a plurality of power supplies with different potentials, and the plurality of different integrated circuit chips are arranged. A fluorescent display device, characterized in that a part of the conductor wiring connected to a power source at a potential is connected to the external terminal at the same potential via either a diode or a Zener diode.