GB2282915A

GB2282915A - Keyboards

Info

Publication number: GB2282915A
Application number: GB9423118A
Authority: GB
Inventors: Fumiyoshi Oono; Tomonobu Watanabe; Yoshitada Yaginuma
Original assignee: Hitachi Telecom Technologies Ltd
Current assignee: Hitachi Telecom Technologies Ltd
Priority date: 1991-03-27
Filing date: 1992-03-25
Publication date: 1995-04-19
Anticipated expiration: 2012-03-25
Also published as: GB9423118D0; GB2282915B

Abstract

A panel unit for a dealing board has a keyboard unit comprising a panel (24), a rubber sheet (22) having a plurality of movable switch contacts (22a), a printed substrate (21) having a plurality of fixed switch contacts (21), and buttons (23) inserted into a plurality of holes (24a) formed in the panel so as to move in up-and-down direction in order to make the printed substrate contact (21a) come into contact with the contacts (22a) of the rubber sheet (22). The buttons have engagement portions (23a) adapted to prevent the buttons from coming out of the keyboard. Relief holes (21b and 22c) are formed at the portions of the rubber sheet (22) and the printed substrate (21) facing the engagement portions (23a), which are movable through the relief holes when the buttons are pushed. <IMAGE>

Description

SPECIFICATION Title of the Invention PANEL UNIT OF DEALING BOARD Background of the Invention Field of the Invention The present invention relates to a panel unit of a dealing board adapted to be employed in terminals of banks and financial organizations.

Description of the Prior Art Nowadays, the terminal of the banking organizations uses a dealing system carrying out transactions or dealings of securities, shares, and foreign exchange by means of telephone lines. A unit of such dealing system has a dealing board provided with operating portions and multi-function telephones and the like, a desk on which the dealing board is installed. The dealing system is constructed by installing a plurality of the desks in a dealing room.

FIG 28 shows a conventional desk 50 installed in the dealing room. The desk 50 has an operation part 51 having various telephoning functions and a dealing board 53 having a hand-set 52, respectively placed on the desk. Further, the desk 50 has a display appliance 54 placed on the rear part of the desk so as to show encomic information and the like.

In order to use the dealing board 53 as a communication means1 the dealing board provides a set panel units containing a dial operating portion 55, a displaying portion 56 of, for example, a liquid crystal display and the like showing a name of the sender, a volume dial 57 for controlling sound volume of the hand-set 52 and dark-and-light level of the displaying portion 56, and a set of one-touch dial buttons 58 (hereinafter referred to as a button merely) for calling out the particular or appointed customer in a one-touch manner through the telephoning lines or network.

Each button 58 has a label on which a name of the client is printed and stucked onto its top face in order to shown whom the button relates.

Because the clients whom the dealing board 53 is used are differed from each other, it has been necessary to paste different set of labels for different dealing boards 53 to the top faces of the buttons 58 in accordance with the prior art. It has been difficult to mass-product the dealing boards and cope with a change-demand occurred when personal changes and the similar change are done in client companies.

FIG 30 shows one of the apparatus for solving such problem of the conventional method. According to the prior art, a liquid crystal indicator 59 is installed by a button 58 as shown in FIG 30. Names of the customers are indicated on the liquid crystal indicator 59 of the panel unit of the conventional dealing board can be easily changed by means of a controlling of the software of the computer.

According to the prior art, due to a narrow space for containing the mounted parts of the panel unit, the indication device is restricted to ones of a liquid crystal, such as the liquid crystal indicator 59. It is noted that the characters displayed on the indicator 59 of such kind is not clear and a viewing angle is narrow. In addition, the liquid crystal indicator 59 must be mounted on every low of the buttons 58, so that an electric wiring of the liquid crystal indicator 59 is made complicated and a mounting operation of the liquid crystal indicator 59 necessitates much hand-work.

According to another indication method of the customer names on the panel unit, a touching panel is placed on the top face of a plasma display device and the like, so that it is possible to recognize the names of the customers without labels attached onto the top faces. According to such panel unit, when light of ultraviolet ray LEDs arranged on the top face of the display device in a matrix shape is interrupted by a finger of the operator, the position of the finger is detected and it is a function of a switch. As a result, there is no feeling of pressing the buttons and an operability of the panel unit is deteriorated. Because the indicator 59 is directly touched, the indicator 59 is apt to become dirty deteriorating visibility of the indicators.

Additionally, the conventional dealing board 53 used as a terminal of financial organizations or companies deals with financial transactions by means of telephone lines, so that it is necessary to provide telephone functions and a keyboard for using these telephone functions.

In the conventional dealing board 53, the keyboard is made and used as a unit and the united keyboard has operation buttons as shown in FIG 31 and FIG 32.

In detail, the operation button shown in FIG 31 consists of a button 58, an electric conductive contacting rubber 59 placed below the button 58, a printed substrate 61, and a panel 62 covering the printed substrate 61. The button 58 is adapted to be urged upwardly by a resiliency of the electric conductive contact rubber 59. An outwardly projected engagement portion 63 is formed on the lower and outer circumferential portion of the button 58. Because the engagement portion 63 engages with the bottom face of the panel 62, the button 58 doesn't get out of place from a hole 64 of the panel 62.

When the button 58 such constructed above is pressed, the button 58 lowers by a stroke S and a contact portion 65 placed on the electric conductive contact rubber 59 comes in contact with contacts 66 on the printed substrate 61 leading electricity between these contacts 66. It is apparent that the low end of the button 58 is separated from a top face of the electric conductive contact rubber 59 by a gap X2, thereby the former cannot come in contact with the latter even when the contact portion 65 comes in contact with these contacts 66.

When a thickness of the panel 62 is shown by D, a height of the engagement portion 63 is C, and a thickness of the electric conductive contact rubber 59 is B, a total of D, C, and B, as well as the stroke S and the gap X2 equals to a thickness size A measured from the top face of the' printed substrate 61 to the top face of the panel 62.

Other operation buttons shown in FIG 33 and FIG 34 have been used in the field. The button shown in FIG 33 has a dome-like button 68, and a polyester sheet 67 having its upper surface printed and covering the button 68. Another button shown in FIG 34 has a silicoon rubber sheet 69 in addition to the dome-like button 68 and the polyester sheet 67, and a different button 70 connected to the silicoon rubber sheet 69. It is apparent that the flat button 70 is placed on and above the dome-like button 68. A thickness size A of the button shown in FIG 34 measured from the top face of the printed substrate 61 to another top face of the panel 62 is exceedingly shorter than the size A of the operation button shown in FIG 31.

The conventional operation buttons 68 and 70 shown in FIG 33 and FIG 34, respectively have strokes S of only about 1 mm because a molding process of polyester material has a restriction and life of the polyester sheet 67 is short.

Consequently, operation or pressing feeling of the buttons 68 and 70 are bad. When these buttons 68 and 70 are employed in the dealing board and they are used frequently, they will be broken before long periods. It is said that they haven't reliability in operation.

When the thickness size measured from the top face of the printed substrate 61 and the top face of the button 58 in the conventional keyboard unit 53 is made small, insulation resistance between the printed substrate 61 and the button 58 becomes low, static electricity noise impressed to around the button 58 through its top side is transferred to a signal pattern 72 connected to an electrode of the contact 71 shown in FIG 35, and entered into an electronic circuit from a through hole 73 through a connector, thereby generating errors in operation.

Summary of the Invention According to the present invention, a panel unit of the dealing board provided with an indicating portion consisting of a plurality of buttons and a display is provided. The panel unit has a keyboard unit consisting of a printed substrate having a plurality of buttons and a contact sheet and clicking means giving click feeling to the operator when the operator pushes the button. The keyboard unit is provided on the display. The printed substrate of the keyboard unit has a plurality of through holes through which indications of respective buttons on the display can be seen. The contents indicated on the display can be easily changed by changing the computer software, as well as click feeling can be obtained when the buttons are pressed or pushed improving an operability of the dealing board of the present invention.

According to the keyboard unit of the present invention, an electric conductive contact rubbers and a panel are provided on the printed substrate. The panel has a plurality of holes open or formed therein and the plurality of buttons are vertically movably inserted into the plural holes so as to contact the contacts of the printed substrate and the contact portions of the electric conductive contact rubber.

The portions facing engagement portions so formed in the material of the button as to prevent the button from coming out of the keyboard unit have relief holes through which the engagement portion enters when the button is pressed.

Consequently, it is possible to make small, by only thining the electric conductive contact rubber and the panel without changing the stroke of the button, the thickness size measured from the top face of the printed substrate and the top face of the panel in order to lessen a non-watchable range of the display without any deterioration on a manual feeling of the buttons.

Also, according to the keyboard unit of the present invention, which unit having the printed substrate provided with the electric conductive contact rubber and the panel, respectively formed on the substrate, a plurality of holes are open on the panel and a plurality of buttons for making the contact of the printed substrate and the contact portion of the electric conductive contact rubber contact to each other are inserted into the holes so as to freely move in a up-and-down direction. Further, the portions facing to the engagement portion of the button which portion prevents the button from coming out of the hole provide with a relief hole through which the engagement portion of the button is inserted when the button is pushed, an earth pattern is formed around the contact of the printed substrate. When the button is pressed, the engagement portion of the button is inserted into the relief hole and lowers without conflict between the button and the electric conductive contact rubber or the printed substrate, as a result, by only making the thicknesses of the electric conductive contact rubber and the panel thin without changing the stroke of the button, it is possible to make small the thickness size measured from the top face of the printed substrate and the top face of the panel and the non-watchable range of the display without deterioration of the manual feeling. Because static electricity noise impressed on around the button from its top face side is transferred to the earth pattern around the contact before it is transferred to a contact and the signal pattern connected to the contact, it is possible to prevent static electricity noise from transferring to the signal pattern in order to prevent the electronic circuits from erroneous functioning due to such static electricity noise.

Consequently, the first purpose of the present invention is to provide a panel unit of the dealing board in which the indications of the buttons indicated on the display is easily seen and the computer software easily changes the indication contents.

The second purpose of the present invention is to provide a panel unit of the dealing board in which the thickness size from the top face of the printed substrate to another top face of the panel is small and having operation buttons of good in their manual feeling.

The third purpose of the present invention is to provide a panel unit of the dealing board of a small thickness size measured from the top face of the printed substrate to the top face of the panel, operative buttons of good in manual feeling or touch sensing, and no static electricity noise impressed to about the button from its top and entered to the electronic circuits generating no error function of the circuits.

Brief Description of the Drawings FIG 1 is a plan view showing a panel unit of the dealing board according to one embodiment of the present invention.

FIG 2 is a plan view of the indication portion constructing the panel unit.

FIG 3 is a side view of the indication portion above.

FIG 4 is an exploded perspective view of the indication portion.

FIG 5 is an enlarged view of the important portion of the indication portion.

FIG 6 is an enlarged sectional view of the important portion.

FIG 7 is a plan view showing the keyboard unit according to another embodiment of the present invention.

FIG 8 is a front view of the another embodiment above.

FIG 9 is a side view of the another embodiment.

FIG 10 is an enlarged section showing the operation buttons and its neighboring portion of the keyboard unit according to the other embodiment.

FIG 11 is a section taken along a line E-E shown in FIG 10.

FIG 12 is a section depicting an operation condition of the operation button.

FIG 13 is a section taken along a line F-F of FIG 10.

FIG 14 is a section depicting an operation condition of the operation button.

FIG 15 is a diagram of curves depicting strokes and downing force of the electric conductive contact rubber.

FIG 16 is a diagram of the curves depicting strokes and pressing force in experiments.

FIG 17 is a section of the operation button according to another embodiment of the present invention.

FIG 18 is a section showing an operation condition of the operation button.

FIG 19 is a flat view of another embodiment of the keyboard according to the present invention.

FIG 20 is a front view of the embodiment shown in FIG 19.

FIG 21 is a side elevation of the embodiment above.

FIG 22 is an enlarged plan view of a part about the operation button on the keyboard unit.

FIG 23 is a section taken along the line G-G shown in FIG 22.

FIG 24 is a section depicting an operation condition of the operation button.

FIG 25 is a section taken along the line H-H shown in FIG 22.

FIG 26 is a section showing an operation condition of the operation button.

FIG 27 is a detailed view of a contact in the keyboard unit.

FIG 28 is a perspective view of the desk installed on the conventional dealing board.

FIG 29 is a perspective view of a panel unit of the conventional dealing board.

FIG 30 is a section of the panel unit shown in FIG 29.

FIG 31 is a section of an operation button installed on the conventional keyboard.

FIG 32 is a section showing an operation condition of the operation button.

FIG 33 is a section of another operation button employed on the conventional keyboard unit.

FIG 34 is a section of still another operation button used on the conventional keyboard unit.

FIG 35 is a detailed view of the contact installed on the conventional keyboard unit.

Description of the Embodiments As shown in the plan view of FIG 1 of the panel unit used in the operation portion of the dealing board according to the present invention, the main body 1 of the panel unit has a dial operation portion 2, a liquid crystal indicator 3 displaying names and the like of senders, and indicating portion 4, respectively installed on the main body 1.

The indicating portion 4 consists of a single display unit 5, such as a liquid indicator and a plasma display and etc. and a keyboard unit 6 placed on the display unit 5.

The display unit 5 enables to any information at any position thereon by means of a software. The characters 5a in, for example, two lines and four rows are shown at through holes 7b, each placed adjacent to a number of protruded buttons 7a, and frame indications 5b enclosing these characters Sa. These protruded buttons 7a are formed on a surface sheet 7 consisting of the keyboard unit 6.

These frame indications 5b show one thin line, double thin lines, a thick line, a bold line, or flicking line in order to show various operation conditions of communication receiving, communication sending, and a usage of another machine of the same group. The keyboard unit 6 is placed on the display unit 5 through a reflecting plate 8 in order to make the display unit 5 easy to see. As shown in FIG 4, the keyboard unit 6 is constructed by piling in order a printed substrate 10, an insulation sheet 11, a contacting sheet 12, a click sheet 13, and a top face sheet 7.

The printed substrate 10 has carbon contacts 10a, respectively printed at places corresponding to the positions of a plurality of buttons 7a formed on the top face sheet 7.

A belt-like through holes 10b are formed at the positions corresponding to these of the frame indication 5b of the display unit 5, therefore contents of the display unit 5 can be seen through these holes 10b.

If necessary, a plurality of chips LED 10c are installed on the top face and at both sides of the printed substrate 10 in order to indicate operation condition of the corresponding button 7a through function of the chips LED 10c. A connector 10d of a face-attaching type is attached to a rear face of the printed substrate 10, thereby the carbon contacts 10a and the chips LED 10c on the printed substrate 10 are electrically connected to another printed substrate (not shown) through the connector 10d.

While, the insulation sheet 11 is formed on a non color transparent film and has a set of through holes lla and llb of square and round at positions corresponding to that of the carbon contacts 10a and the chips LEDs 10c formed on the printed substrate 10. The carbon contacts 10a on the printed substrate 10 and other carbon contacts 12a formed on the bottom face of the contact sheet 12 are insulated from each other so as to prevent these contacts 10a and 12a from coming in contact with each other while the button 7a on the top face sheet 7 is not pressed.

The contact sheet 12 is made of a non-color transparent film similar to that of the insulation sheet 11 and has a set of carbon contacts 12a placed at positions corresponding to the carbon contacts 10a of the lower printed substrate 10.

These carbon contacts 12a are apparently formed by printing in order to construct a switching function between the carbon contacts '2a and other carbon contacts 10a on the printed substrate 10. The contact sheet 12 has also a set of through holes 12a at positions corresponding to the chips LED 10d on the printed substrate 10.

The click sheet 13 is made of a non-color transparent film and has a doom-like protrusion 13a formed at positions corresponding to the carbon contact 10a of the printed substrate 10 and the carbon contact 12a of the contact sheet 12. The protrusion 13a is adapted to be resiliently deformed when the button 7a of the top face sheet 7 is pressed giving a click-feeling to a finger of the operator, and return to raise the button 7a to its original position when the finger is left from the button 7a.

In addition, the click sheet 13 has a number of through holes 13b formed at positions corresponding to the chips LED 10d on the printed substrate 10.

While, the top face sheet 7 is made of a silicone rubber, and has buttons 7a formed at positions corresponding to the carbon contacts 10a and 12a and long or belt-like through holes 7b formed at positions corresponding to the positions corresponding to the frame indications 5b of the display unit 5 enabling to see the contents of the display unit 5 therethrough.

A number of protrusions 7c a little larger than the chips LED 10c are formed at positions of the printed substrate 10a corresponding to the chips LED 10c so as to accommodate the chips LED 10d.

Operation of the keyboard panel unit of the present invention will be described.

When the panel unit main body 1 is employed to the dealing board, the contents of every button 7a displayed in the display unit 5 can be seen through the through holes 10b and 7b formed in the keyboard unit 6.

As a result, it is possible to easily know the name of the client to which the particular button 7a led by displaying information of the clients at every button 7a.

When a telephone is taken to a client, it is necessary to push the button 7a showing the particular client's name.

The button 7a makes the protrusion 13a of the click sheet 13 resiliently deform, a finger feels a clicking, the contact sheet 12 is pressed making the carbon contact 12a on the bottom of the contact sheet 12 come into contact with the carbon contacts 10a on the printed substrate 10. Therefore, the switch is made ON. Thus, it is possible to call up the client by one-touch operation.

While, the client indications of respective buttons 7a can be easily changed by changing software, therefore it is very easy to carry out a change operation of the clients or customers which is due to personnel changes in the companies.

It is noted that, in order to improve operability of the panel unit of the embodiment above, the top face sheet 7 provided with a number of buttons 7a is employed. It is possible to print the buttons on the click sheet 13 and a finger of the operator directly pushes the click sheet 13 according to an alternation of the panel unit. Also, it is possible to use a flat sheet having the buttons 7a printed thereon or another flat sheet provided with the buttons 7a thermally formed thereon in place of the top face sheet 7.

When the top face sheet 7 is made of a transparent material number, it is possible to see the displayed contents of the display unit 5 without any through openings, such as through holes 7b.

According to the present invention, the keyboard unit 6 is installed on the display unit 5, the display unit 5 can be seen through the through holes 10b open in the keyboard unit 6, a plurality of the buttons 7a are formed on the keyboard unit 6, and respective clients names of each button 7a are displayed on the display unit 5, therefore watching the display unit 5 through the keyboard unit 6 recognizes the particular customer of the particular button 7a making communication with the customers easy and sure.

Because the contents displayed on the display unit 5 can be easily changed by changing software, it is possible tp previously mass produce the dealing board 6 and decide the particular contents displayed on the button according to the particular customer after purchase ordering of the customer. Again, it is easy to set the display contents of the button according to respective customers, change the display contents after they are changed due to personnel changes in the client companies by means of changing software.

When the operator pushes the button 7a, he or she feels a clicking sound and can recognize the button 7a is surely pressed, therefore operability of the panel unit is exceedingly improved. In addition, when the top face sheet is made of a transparent material, it is possible to easily obtain a panel unit of water-proof construction preventing water, foreign matter or wetty air from invading or entering to the keyboard unit 6 and the display unit 5.

FIG 7 to FIG 14, respectively show another embodiment of the key board unit used as an operation part of the dealing board.

It is apparent that a panel 24 has a plurality of square openings 24a arranged along vertical lines or rows and horizontal lines or columns, and buttons 23 each fitted into the square openings 24a.

The buttons 23 has a shape of thin plates. The button 23 has an engagement portion 23a formed at lower corners of the button 23. The engagement portion 23a is inserted to a bottom face of the panel 24 and engaged with the bottom face.

The button 23 has projections or protrusions 23b formed on its bottom face coming in contact with a top face of a contact portion 22a of an electric conductive contact rubber 22.

The electric conductive contact rubber 22 is adapted to intimately contact with a printed substrate 21. Each button 23 has, for example, two contact portions 22a protruding upward and attached on the bottom face of the button 23. A thin portion 22b of the contact portion 22a has a resiliency urging the button 23 upward. Two contacts 21a adapted to be electrically connected to each other through the contact portion 22a are formed on the printed substrate 21. It is apparent that these contacts 21a are placed under the contact portion 22a.

In addition, the electric conductive contact rubber 22 has a recess portion or relief hole 22c to which portion the engagement portion 23a projected from the corner of the button 23 is applied. The printed substrate 21 has another relief hole 22b formed therein. The engagement portion 23a of the button 23 is loosely inserted downward through these relief holes 22c and 21b.

The thickness of the electric conductive contact rubber 22 is decided so as not to project of the front end of the engagement portion 23a lower than the bottom face of the printed substrate 21 even when the button 23 is pressed and the contact portion 22a lowers by the stroke S.

Operation of the panel unit of the present invention will be explained with reference to the accompanying drawings.

When the button 23 is not pressed, resiliency of the thin portion 22b of the electric conductive contact rubber 22 raises the button 23 to a position shown in FIG 11, at which position the engagement portion 23a engages with the bottom face of the panel 24 preventing the engagement portion 23a from coming out of the hole 24a.

Next, when the button 23 is pressed, the contact portion 22a strokes by a distance S and comes into contact with the contact 21a on the printed substrate 21 leading the contacts 21a to each other. Then, the engagement portion 23a of the button 23 lowers through the relief holes 22c and 21b, respectively formed in the electric conductive contact rubber 22 and the printed substrate 21. Apparently, there is no intervention or conflict between the button 23 and the electric conductive contact rubber 22, and the button 23 and the printed substrate 21.

A thickness size A' measured from a top face of the printed substrate 21 to a top face of the panel 24 is determined with a thickness size B of the electric conductive contact rubber 22 and another thickness size D of the panel 24. The thickness size Al doesn't have relation to the stroke S, so that even when the stroke S becomes large, the thickness size A' can be made small by making these thickness sizes B and D small. Consequently, it is possible to make considerably small of a non-seeing range Z' for the display 25 even when the operator watches the display 25 slantly as shown by a dotted line Y in FIG 13 through an open portion 21c formed in the printed substrate 21.

Next, pressing down characteristic of the button 23 will be explained.

Analysis value of pressing feeling of the button 23 is decided by the following equation.

V = Operation load P1 / restoring load P2 x stroke S When the value V becomes larger than 1.5, pressing feeling of the button 23 is said good.

FIG 16 shows experimental results of characteristics of strokes and pressing forces with reference to various materials of the electric conductive contact rubber.

The following table 1 shows several analysis values V obtained from the experimental results. Comparing the analysis values to pressing feeling of a real button 23 decides that the best material for the button 23 is QGR4-60A (hardness 60').

Table 1 : Comparing of Analysis Value V of Pressing Feeling

material designed Black sample Black sample value (Hardness 50) (Hardness 55) V 1.90 1.44 1.54 Black sample Black sample Black sample Black sample (Hardness 60) (Hardness 60) (Hardness 60') (Hardness 70) 1.49 1.35 1.56 1.36 The size of the button 23 is a factor determining operability of the button. Two electric conductive contact rubbers 22 correspond to one button 23 as mentioned above, so that it is possible to exceedingly make the button 23 large and obtain some pressing feeling even when the corner of the button 23 is pressed improving its reliability.

FIG 17 and FIG 18 show another embodiment of the panel unit of the present invention in which the engagement portion 23a of the button 23 projects downward from the lower face of the printed substrate 21 and the engagement portion 23a engages with the lower face of the printed substrate 21, preventing the button 23 from coming out of the square hole 24a of the panel 24. If there is a space under the printed substrate 21, it is possible to employ such construction and set at will the stroke S of the button B.

The keyboard unit has relief holes 22c and 21b formed at positions corresponding to the engagement portion 23a functioning as a coming-out preventor for the button 23 from the hole 24a of the panel 24. As a result, the engagement portion 23a of the button 23 enters, when the button 23 is pressed, into the relief holes 22c and 21b and the engagement portion 23a doesn't collide with the electric conductive contact rubber 22 and the printed substrate 21. Consequently, the electric conductive contact rubber 22 and the panel 24 are made thin, therefore a thickness size measured from the top face of the printed substrate 21 to the top face of the panel 24 can be made small without reducing the stroke of the button 23.

Consequently, a non-watching range of the display 25, when the display 25 is slantly seen, can been considerably reduced and as a result the display 25 can be easily watched.

Because the stroke attained, when the button 23 is pressed, is the same as that attained when the conventional electric conductive contact rubber is used, operation feeling is not deteriorated, as well as durability of the button 23 is exceedingly improved comparing to that made of polyester sheet. A high reliability is attained in the product of the panel unit of the present invention.

Another embodiment of the keyboard unit adapted to be used in the operation portion of the dealing board is shown in FIG 19 to FIG 27.

As shown, the panel 34 has a number of square holes 34a arranged in vertical rows and horizontal columns and buttons 33 are fitted into these holes 34a.

The button 33 is a thin one and has an engagement portion 33a adapted to engage upward with the lower face of the panel 34, which portion 33a projects from the lower corner portion. On the lower face of the button 33, there are protrusions 33b protruded so as to contact with the top face of the contact portion 32a of the electric conductive contact rubber 32.

The electric conductive contact rubber 32 is placed so as to intimately contact with the printed substrate 31.

On the bottom face of the button 33, there are, for example, two contact portions 32a projecting upward. The buttons 33 are urged upward due to resiliency of the thin portion 32b of the contact portion 32a. A pair of contacts 31a led by the contact portion 32a as formed on the printed substrate 31 below the respective contact portions 32a.

The portions of the electric conductive contact rubber 32 and of the printed substrate 31, to which portions the engagement portions 33a projected from the corners of the button 33 abut, have relief holes 32c and 31b. The engagement portions 33a of the button 33 are loosely and downward inserted through the relief holes 32c and 31b.

The thickness of the electric conductive contact rubber 32 is decided so as to prevent the ends of the engagement portion 33a from projecting downward out of the lower face of the printed substrate 31 even when the button 33 is pressed and the contact portion 32a lowers by a stroke S.

The carbon contact 35 shown in FIG 27 has a pair of contacts 31a and one earth pattern 35b. The earth pattern 35b surrounds the contacts 31a. The earth pattern 35b has a solder coating thereon in order to improve its conductivity.

Electrodes of the contacts 31a have buyer holes 35c. In order to prevent static electricity noise from conveying, a signal pattern (corresponding to q shown in FIG 35) connected to the contact la is not provided on a face of the contact 31a. In order to improve reliability of electric connection, two buyer holes 35c are formed on the electrode of the contact 31a.

Next, operation will be explained. When the button 33 is not pressed, resiliency or elasticity of the thin portion 32b of the electric conductive contact rubber 32 raises the button 33 to its position shown in FIG 23, and the engagement portion 33a engages with the lower face of the panel 34 preventing the button 33 from dropping out of the hole 34a.

Pressing the button 33 lowers the contact portion 32a by the stroke S and the contact portion 32a comes in contact with the contacts 31a in order to electrically connect these contacts 31a to each other. Then, the engagement portion 33a of the button 33 lowers through the relief holes 32c and 31b formed in the electric conductive contact rubber 32 and the printed substrate 31 without any conflict of the electric conductive contact rubber 32 and the printed substrate 31.

The thickness size A' measured from the top face of the printed substrate 31 to the top face of the panel 34 is determined with reference to the thickness size B of the electric conductive contact rubber 32 and the thickness size D of the panel 34, without relation to the stroke S.

Consequently, it is possible to make the thickness size A' small by making these thickness sizes B and D of the electric conductive contact rubber 32 and the panel 34 even when the stroke S is large. As a result, it is possible to reduce considerably the non-seeing range Z' of the display 36 even when the operator watches the display 36 slantly through the open portion 31c formed in the printed substrate 31 as shown by the sight line Y in FIG 25.

Static electricity noise disadvantageously impressed to the button 33 through a finger tip of the operator pressing the button due to the thickness size A' of small is conveyed to the earth pattern 35b provided with a solder coating and placed around the contacts 31a, thereby a conveyance of static electricity from the buyer holes 35c formed on the electrode of the contact 31a to the signal pattern is surely prevented. The earth pattern 35b is formed simultaneously with the signal pattern and the buyer holes 35c, a manufacturing cost of the printed substrate 31 is low.

Concerning the keyboard unit provided with the printed substrate 31, the printed substrate 31 has the electric conductive contact rubber 32 and the panel 34, respectively formed thereon and the buttons 33 for contacting the contact 31a of the printed substrate 31 to the contact portion 32a of the electric conductive contact rubber 32 is inserted into a plurality of holes 34a open in the panel 34 so as to move freely and vertically. In addition, relief holes 32c and 31b, through which the engagement portions 33a are inserted when the button 33 is pressed, are formed in the portions corresponding to the engagement portions 33a adapted to prevent the button 33 from coming out of the relief holes 32c and 31b, and the earth pattern 35b is formed around the contact 31a of the printed substrate 31, thereby the engagement portion 33a of the pressing button 33 is inserted through the relief holes 32c and 31b and lowers without any intervention of the electric conductive contact rubber 32 and the printed substrate 31.

In consequence, it is possible to make the thickness size measured from the top face of the printed substrate 31 and the top face of the panel 34 small without lessening the stroke of the button 33.

The non-recognizable or watchable range of the display 36 when the display 36 is slantly seen is exceedingly reduced improving a visuability of the display 36 or without a deterioration of the visuability. Additionally, an operation or manual feeling of the operator obtained when he or she presses the button 33 is not deteriorated, as well as a durability of the mechanism of the panel unit is improved very much attaining its high reliability.

According to the panel unit of the present invention, static electricity impressed to the button 33 when it is pressed is transferred to the earth pattern 35b around the contacts 31a before being transferred to the signal pattern connected to the contacts 31a, therefore static electricity is not transferred to the signal pattern preventing the electronic circuits from erroneous operating due to such static electricity noise and heightening a reliability of the mechanism or system.

Claims

1. A panel unit of a dealing board provided with a keyboard unit comprising a panel (24), a rubber sheet (22) having a plurality of switch contacts on a printed substrate, and buttons (23) inserted into a plurality of holes (24a) formed in the panel so as to move in up-and-down direction making contacts of the printed substrate contact with the contact portions (22a) of said rubber sheet (22), wherein the buttons have engagement portions (23a) adapted to prevent the buttons from coming out of the keyboard, and relief holes (22c and 21b) are formed at the portions of the rubber sheet (22) and the printed substrate (21) facing the engagement portions (23a), through which relief holes the engagement portions (23a) being inserted when the button is pushed.

2. The panel unit of a dealing board according to claim 2, wherein the keyboard unit has earth patterns (35b) provided with around respective contacts of said printed substrate (21) so as to prevent static electricity noise from generating.