JPH0714532A - Fluorescent character display device - Google Patents

Abstract

PURPOSE:To miniaturize the whole device provided with a micro-processor, make it lightweight, reduce the cost, and improve reliability. CONSTITUTION:Phosphor display sections 25 are formed via anodes on a glass substrate 22 constituting the lower face of an envelope 21. A circuit element mount section 29 is formed at a portion of the glass substrate 22 in the envelope 21, and IC chips 30 of a micro-processor and its peripheral circuit elements 32 are mounted on the circuit element mount section 29. An external lead substrate section 33 is integrally provided on the glass substrate 22, and an external terminal 34 and a resistor 35 are formed on the external lead substrate section 33 by printing. The IC chips 30 of the micro-processor, the peripheral circuit elements 32, and the resistor 35 are all mounted on one glass substrate 22, and these IC chips 30 and peripheral circuit elements 32 are stably operated in the vacuum envelope 21 without being affected by the external environment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called chip-in-glass type (hereinafter abbreviated as "CIG type") fluorescent display in which a phosphor display section and a circuit element mounting section are arranged in a vacuum envelope. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, in this type of CIG type fluorescent display device, a driving IC chip constituting a driving circuit is mounted on a substrate, and a power source and a control signal are externally applied to the driving IC chip. The phosphor display unit on the substrate is driven. This CIG type fluorescent display device displays, for example, time and various information according to an input control signal, and there is one using a microprocessor for controlling these displays. In this device, as shown in FIG. 4, the conventional CIG type fluorescent display device 12 is mounted on a printed circuit board 11, and the printed circuit board 1 is mounted.
Microprocessor 13 and its peripheral circuit elements 14
Also, each lead 15 of the CIG type fluorescent display device 12 is soldered to the printed circuit board 11.

[0003]

However, in the above-mentioned conventional configuration, in order to provide the microprocessor 13 and its peripheral circuit element 14, a large-sized printed circuit board 11 is separately provided.
Is required, the number of parts and the number of assembling steps are increased to increase the product price, and the entire device is enlarged,
It also goes against the demand for smaller size and lighter weight. Moreover, the wiring length becomes long, which may adversely affect the reliability such as noise resistance.

The present invention has been made in view of the above circumstances, and an object thereof is to realize a compact and lightweight device and a low price of the entire device while having a microprocessor, and to improve reliability. Another object of the present invention is to provide a fluorescent display device that can do the above.

[0005]

In order to achieve the above object, a fluorescent display device of the present invention is provided with a phosphor display portion and a circuit element mounting portion on a substrate, and these are housed in a vacuum envelope. In the device described above, a microprocessor is mounted on the circuit element mounting portion, and an external extraction substrate portion protruding outside the envelope is integrally provided on the substrate, and external terminals are formed on the external extraction substrate portion. A circuit element forming a peripheral circuit of the microprocessor is mounted on the circuit element mounting portion or the external extraction substrate portion.

[0006]

The circuit element mounting portion located inside the envelope and the external extraction substrate portion projecting outside the envelope are integrally formed on the substrate on which the phosphor display portion is formed. And, focusing on the fact that the inside of the envelope (circuit element mounting part) is in a vacuum state and is not easily affected by the external environment, the microprocessor is mounted on the circuit element mounting part inside the envelope. At the same time, the circuit elements forming the peripheral circuit of the microprocessor are mounted on the circuit element mounting portion or the external extraction substrate portion. This eliminates the need for a large-sized printed board on which a conventional microprocessor is mounted, and also eliminates the need for soldering the leads and the printed board. Moreover, the number of external terminals (leads) formed on the external lead-out board portion can be significantly reduced by mounting the microprocessor and the circuit elements around the microprocessor inside the envelope as compared with the conventional case. Further, the microprocessor and its peripheral circuit elements can operate stably in the vacuum envelope without being affected by the external environment, and the wiring length can be shortened to improve the noise resistance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. The envelope 21 is sealed in a vacuum state by bonding a cover glass 24 to a glass substrate 22, which is a substrate, via a spacer glass 23. The glass substrate 2
2, an anode (not shown) is formed, and a phosphor display unit 25 is formed on the upper surface of this anode by printing or the like. The phosphor display unit 25 is covered with a mesh grid 26 provided on the glass substrate 22. Above the grid 26, a plurality of filaments 27
And each end of each filament 27 is fixed to a supporting electrode 28 provided on the glass substrate 22 by welding or the like.

A circuit element mounting portion 29 is formed on the right side of the envelope 21 on the glass substrate 22, and an IC chip 30 is die-bonded on the circuit element mounting portion 29 with, for example, silver glass paste. There is. A circuit of a microprocessor having a CPU, a RAM and the like and a drive circuit for driving the phosphor display unit 25 are collectively formed on the IC chip 30, and a wiring pattern (not shown) formed on the glass substrate 22. No.) is connected with a bonding wire 31. Characters and the like are displayed by applying the drive signal output from the IC chip 30 to the anode (phosphor display unit 25) through the wiring pattern.

Further, the circuit element mounting portion 29 is mounted with chip components such as resistors, capacitors and semiconductor diodes which form the peripheral circuits of the microprocessor, and various circuit elements 32 such as a crystal oscillator. In this case, by locating the circuit element mounting portion 29 outside the filament 27, the IC chip 30 and the circuit element 32 are protected from thermoelectrons and the like emitted from the filament 27.

Further, the glass substrate 22 is integrally formed with an external take-out substrate portion 33 projecting to the outside of the envelope 21, and the external take-out substrate portion 33 has a plurality of external terminals 34. Are formed by vapor deposition or printing. Further, a resistor 35 and a fixed switch contact 36, which are peripheral circuit elements of the microprocessor, are formed on the external extraction substrate section 33 by thick film printing. still,
On the surfaces of the external extraction substrate portion 33, the circuit element mounting portion 29 and the phosphor display portion 25, the tip connection portion of the external terminal 34, the switch fixed contact 36, the IC chip 30 and the circuit element 32.
An overcoat glass (not shown) is printed and fired except for the mounting portion.

On the other hand, the envelope 21 (fluorescent display tube) is shown in FIG.
As shown in FIG. 5, the socket pins 38 housed in the resin case 37 and insert-molded in the resin case 37 are connected to the external terminals 34 of the external extraction substrate section 33 by press fitting. A frame-shaped lid 39 is attached to the upper surface of the resin case 37 by engaging claws 40 and 41. A switch button 42 is held on the lid 39, and a movable contact 43 formed at the lower end of the switch button 42 is configured to be able to come into contact with and separate from the fixed switch contact 36 of the external extraction substrate 33. By pushing the switch button 42, the operation mode (display mode) of the microprocessor can be switched. A window portion 44 for visually recognizing the phosphor display portion 25 is formed in the lid portion 39, and a filter 45 for blocking external light is sandwiched inside the window portion 44.

An example of the manufacturing procedure of the fluorescent display device configured as described above will be described below. First, a resistor 35 and a fixed contact 36 for a switch are thick-film printed and baked on the external extraction substrate portion 33 of the glass substrate 22, and then a wiring pattern and an anode are formed on the glass substrate 22 by vapor deposition or printing. After that, after printing and baking the phosphor display unit 25 on the anode of the glass substrate 22, the tip connection portion of the external terminal 34 is formed on the surface of the external extraction substrate unit 33, the circuit element mounting unit 29, and the phosphor display unit 25. And fixed contacts for switches, IC
Overcoat glass (not shown) is printed and fired except for the parts where the chips 30 and the circuit elements 32 are mounted. Next, the IC chip 30 and the circuit element 3 are attached to the circuit element mounting portion 29.
After mounting 2, the grid 26 is mounted on the phosphor display unit 25, and the filament 27 is placed on the grid 26.
Cross over. Thereafter, the cover glass 24 is bonded to the glass substrate 22 via the spacer glass 23, and the envelope 21
Then, the inside of the envelope 21 is evacuated to a vacuum state. Vacuum exhaust hole (not shown) used in this exhaust process
Is heated and sealed after the evacuation is completed.

The envelope 21 (fluorescent display tube) manufactured as described above is housed in a resin case 37, and in the process,
The external terminal 34 of the external extraction substrate 33 is attached to the resin case 37.
It is press-fitted into the socket pin 38 of. Then, a filter 45 for blocking external light is provided on the upper surface (cover glass 24) of the envelope 21.
And the lid 39 from above to cover the resin case 37.
When the engaging claws 40 and 41 are elastically engaged by press-fitting into the upper surface of the above, the assembling process of the fluorescent display device is completed.

The operating principle of the fluorescent display device constructed as described above is as follows. That is, by supplying an electric current to the filament 27 through the support electrode 28, the filament 27 is heated to radiate thermoelectrons toward the phosphor display unit 25, and at the same time, a positive voltage is applied to the mesh grid 26, Accelerate thermoelectrons. In this state, the driving signal output from the IC chip 30 causes each phosphor display unit 2 to
When a positive voltage is selectively applied to 5, the accelerated electrons collide with the surface of the phosphor display unit 25 to which the positive voltage is applied, causing an excited light emission phenomenon and displaying characters and the like. . At this time, the display operation is controlled by the microprocessor incorporated in the IC chip 30.

According to the first embodiment described above, attention is paid to the fact that the inside of the envelope 21 is in a vacuum state and is less likely to be affected by the external environment. Since the peripheral circuit element 32 (mainly a chip component) is mounted on the circuit element mounting portion 29 in the envelope 21, the IC chip 30 and the peripheral circuit element 32 operate stably without being affected by the external environment. As a result, the wiring length is shortened, noise resistance can be improved, and reliability can be improved. In addition, the glass substrate 22 is integrally provided with the external extraction substrate section 33, and the external extraction substrate section 3 is provided.
Since the external terminal 34 and the resistor 35 are formed on the circuit board 3 and all the circuit elements 32 and the resistor 35 around the microprocessor are mounted on the single glass substrate 22, the conventional large-sized printed circuit board becomes unnecessary, and the number of parts is reduced. In addition, the work of soldering the leads and the printed circuit board becomes unnecessary, and the number of assembling steps can be reduced. In addition, by mounting the IC chip 30 of the microprocessor and the circuit elements 32 around it in the envelope 21, the number of external terminals 34 (leads) formed on the external extraction substrate section 33 can be significantly increased as compared with the conventional case. It can be reduced, and in combination with the above circumstances,
It is possible to realize weight reduction and price reduction.

In the first embodiment, the resistor 35, which is one of the peripheral circuit elements of the microprocessor, is formed on the external extraction substrate 33 outside the envelope 21 by thick film printing. The resistance value of the circuit element can be easily adjusted by trimming or the like to facilitate circuit adjustment, and the area increase of the circuit element mounting portion 29 in the envelope 21 can be minimized. There is also an advantage that the increase in cost due to the increase in the vacuum sealed portion of the container 21 can be minimized.

On the other hand, FIG. 3 shows a second embodiment of the present invention. In this second embodiment, the socket pin 46 is press-fitted and connected to the external extraction substrate portion 33 downward. Further, the circuit element mounting portion 47 is located inside (lower side) of the filament 27, and the IC chip 30 of the microprocessor is mounted on the circuit element mounting portion 47. In the second embodiment, the portion where the conventional leads are arranged is also used as a part of the circuit element mounting portion 47, and the circuit element 32 is also mounted in this portion. As a result, the empty space in the envelope 21 is effectively used, and the size and weight can be further reduced. In this case, the filament 27
In order to protect the IC chip 30 and the like from thermoelectrons and the like emitted from the IC chip 30 and the like, the IC chip 30 and the like may be covered with a protective cover (not shown) made of a metal plate. The other structure is the same as that of the first embodiment.

In both the first and second embodiments, the resistor 35 among the peripheral circuit elements of the microprocessor is formed on the external extraction substrate portion 33 outside the envelope 21 by thick film printing, and other than this. Although the circuit element 32 (mainly a chip component) is located inside the envelope 21, it may be configured such that a part of the chip component is mounted on the external extraction substrate section 33.
It goes without saying that the resistor 35 may be provided in the circuit element mounting portions 29 and 47 in the envelope 21.

In both the first and second embodiments,
The circuit of the microprocessor and the drive circuit are collectively formed on one IC chip 30, but these circuits are formed on different IC chips to form the circuit element mounting parts 29, 4.
A plurality of IC chips may be mounted on 7.

In addition, the present invention can be implemented in various ways within the scope not departing from the spirit of the invention, such as the structure of the resin case 37 and the connection method between the external terminals 34 and the external connection pins may be appropriately changed. Needless to say.

[0021]

As is apparent from the above description, according to the present invention, the microprocessor and its peripheral circuit elements are all mounted on a single substrate on which the phosphor display portion is formed, so that the conventional large size This eliminates the need for a printed circuit board, reduces the number of parts and the number of assembly steps, and realizes small size, light weight, and low cost. Moreover, since the microprocessor and its peripheral circuit elements are mounted in the envelope, the microprocessor and its peripheral circuit elements can operate stably without being affected by the external environment, and the wiring length can be reduced. It can be shortened to improve noise resistance and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a fluorescent display device showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional front view of the entire fluorescent display device.

FIG. 3 is a partially cutaway perspective view of a fluorescent display device showing a second embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view of a conventional fluorescent display device.

[Explanation of symbols]

21 ... Envelope, 22 ... Glass substrate (substrate), 25 ... Phosphor display unit, 26 ... Grid, 27 ... Filament, 29
... circuit element mounting part, 30 ... IC chip (microprocessor), 32 ... circuit element, 33 ... external extraction substrate part, 3
4 ... External terminal, 35 ... Resistor, 36 ... Fixed contact for switch, 37 ... Resin case, 38 ... Socket pin, 42 ... Switch button, 45 ... Filter, 46 ... Socket pin,
47 ... Circuit element mounting part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Takei, 1-1, Showa-cho, Kariya city, Aichi prefecture, Nihon Denso Co., Ltd. (72) Koji Numaki, 1-1, Showa-cho, Kariya city, Aichi prefecture, Nihon Denso Co., Ltd. Incorporated (72) Inventor Masaaki Kobayashi 1-336 Noritake Shinmachi, Nishi-ku, Nagoya-shi Noritake Company Limited Limited (72) Inventor Yasuyuki Kani 3-36 Noritake Shincho, Nishi-ku, Nagoya-shi Noritake Co., Ltd. Company Limited (72) Inventor Shunichi Matsumoto 2160, Yatsunami, Sansu, Yasu-cho, Asakura-gun, Fukuoka 2160 Address, Kyushu Noritake Co., Ltd. (72) Noboru Endo, Yatsunami, Yaku-nami, Yasu-cho, Asakura-gun, Fukuoka 2160 Address Kyushu Noritake Co., Ltd. (72) Inventor Jun Mohri, Yakusu, Yasu Town, Asakura District, Fukuoka Prefecture Kyushu Noritake Co., Ltd.

Claims (1)

[Claims] 1. A fluorescent display device in which a phosphor display section and a circuit element mounting section are provided on a substrate, and these are housed in a vacuum envelope, wherein a microprocessor is mounted on the circuit element mounting section, and An external extraction substrate portion that projects outside the envelope is integrally provided on the substrate, and external terminals are formed on the external extraction substrate portion, and the circuit element that constitutes the peripheral circuit of the microprocessor is mounted on the circuit element. Display unit or the external extraction substrate unit.