CN1866437A - Keyboards and Keyboard Components - Google Patents

Abstract

A keyboard, comprising: a light guide plate capable of transmitting light inside; at least one button disposed on an upper surface of the light guide plate; and at least one reflective pattern fixedly positioned relative to the light guide plate to reflect a portion of light propagating through the interior of the light guide plate toward the button.

Description

Keyboards and Keyboard Components

technical field

The present invention relates to a keyboard for a portable terminal, and more particularly, to a keyboard with a light guide plate and a keyboard assembly.

Background technique

A keyboard for a portable terminal usually has: a plate-shaped elastic backing plate; a plurality of buttons formed on the upper surface of the elastic backing plate, and characters are printed on the upper surface of each button; There is a protrusion (or actuator) which is located at the opposite end of the upper surface of the resilient backing plate. The portable terminal usually has a plurality (ie, 15-20) of light emitting devices used as a backlight source for the keyboard.

FIG. 1 is a cross-sectional view of a keyboard assembly according to the prior art. The keyboard assembly 100 includes a keyboard 110 , a switch plate 150 and a plurality of light emitting diodes (LEDs) 170 .

The keyboard 110 includes: an elastic backing plate 120; a plurality of buttons 140 formed on the upper surface 122 of the elastic backing plate 120, each button 140 is printed with characters, numbers, etc.; The lower surface 124 of the protrusion 130 is opposite to the upper surface 122 of the elastic pad 120 . Each protrusion 130 is aligned with the center of the corresponding key button 140 . The resilient backing plate 120 has a plurality of grooves 126 formed in its lower surface 124 . The groove 126 is around the corresponding protrusion 130 to prevent the LEDs 170 from interfering with the protrusion 130 .

The switch board 150 has a board-shaped PCB (Printed Circuit Board) 155 and a plurality of switches 160 formed on the upper surface of the PCB 155 facing the keyboard 110 . Each switch 160 includes a conductive contact member 162 and a conductive dome 164 that completely covers the contact member 162 .

A plurality of LEDs 170 are mounted on the upper surface of the PCB 155 , and each LED 170 is covered by a corresponding slot 126 of the elastic backing plate 120 .

In operation, when a user presses one of the buttons 140 , the portion of the keyboard 110 located under the pressed button 140 is deformed toward the switch plate 150 . As a result, one protrusion 130 corresponding to the deformed portion drives the corresponding dome 164 , which in turn makes electrical contact with the corresponding contact member 162 .

When designing the switch 160 , the LED 170 cannot be disposed under the corresponding button 140 . The light emitted from each LED 170 passes through the elastic pad 120 to illuminate each button 140 at an oblique angle. As a result, button 140 is dimly illuminated in an uneven manner. Thus, the center of each button 140 appears darker while its periphery is lighter. In this regard, if more LEDs are installed to improve the uniformity of illumination of the button 140, power consumption and manufacturing cost will be increased.

Contents of the invention

Therefore, the present invention has been achieved to solve the above-mentioned problems occurring in the prior art, and to obtain additional advantages by providing a keyboard and keyboard assembly capable of achieving high and uniform brightness while having low power consumption and low cost .

In one embodiment, a keyboard is provided, and the keyboard includes: a light guide plate, through which light can propagate inside; at least one button, which is arranged on the upper surface of the light guide plate; and at least one reflective pattern, which reflects The pattern is fixedly positioned relative to the light guide plate to reflect a portion of light propagating through the interior of the light guide plate towards the button.

According to another aspect of the present invention, there is provided a keyboard assembly, which includes: a keyboard, the keyboard has: a light guide plate through which light can propagate inside; at least one button arranged on the upper surface of the light guide plate; and at least one reflective pattern fixedly positioned relative to the light guide plate to reflect a portion of light propagating through the interior of the light guide plate towards the buttons; and a switch plate having at least one formed on its upper surface facing the keyboard A switch in which the portion of the keyboard deformed toward the switch plate depresses the switch when the button is pressed.

According to still another aspect of the present invention, there is provided a portable terminal, which includes: a switch plate having at least one switch provided on an upper surface thereof; a keyboard having a light guide plate and at least one button, the switch plate having The light plate has an upper surface, a lower surface and a side surface, the at least one button is located above the switch and is provided on the upper surface of the light guide plate; and at least one light emitting device is positioned close to the at least one side surface of the light guide plate, wherein The keyboard has at least one reflective pattern formed on a part of the upper surface or the lower surface of the light guide plate and located under the button, for reflecting a part of the light propagating through the inside of the light guide plate toward the button; and the light guide plate Light panels are made of transparent elastic material.

Description of drawings

The above features and advantages of the present invention will be more apparent through the following detailed description in conjunction with the accompanying drawings. in:

1 is a sectional view illustrating a keyboard assembly according to the prior art;

2 is a sectional view illustrating a keyboard assembly according to a first embodiment of the present invention;

Figure 3a depicts an example of a protrusion according to the invention;

Figure 3b depicts another example of a protrusion according to the invention;

Figure 4 depicts the reflection pattern shown in Figure 2;

Figure 5a is an example of the structure of a light emitting device according to the present invention;

Figure 5b depicts another example of the structure of a light emitting device according to the present invention;

Figure 5c depicts yet another example of the structure of a light emitting device according to the present invention;

6 is a sectional view illustrating a keyboard assembly according to a second embodiment of the present invention; and

7 is a sectional view illustrating a keyboard assembly according to a third embodiment of the present invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. For clarity and conciseness, detailed descriptions of well-known functions and constructions associated therewith are omitted so as not to obscure the gist of the present invention.

FIG. 2 is a sectional view illustrating a keyboard assembly according to a first embodiment of the present invention. As shown in the figure, the keyboard assembly 200 includes a keyboard 210, a switch plate 250 facing the keyboard 210, at least one light emitting device 290, and a second PCB 280.

The keypad 210 includes a light guide plate 220, a plurality of buttons 245, a plurality of protrusions 240, and a plurality of reflective patterns 230 (shown by solid triangles).

The light guide plate 220 retains light propagating therein. The coupled light propagates from one side surface of the light guide plate 220 to the opposite side surface end. The light guide plate 220 can have any shape, such as square. The light coupled inside the light guide plate 220 propagates inside the light guide plate 220 due to total reflection at the interface between the light guide plate and the outer air layer. The light guide plate 220 has elasticity so that the button 245 can return to the initial position after being pressed. That is, the light guide plate 220 has self-restorability, so that it can return to the original shape after being deformed and return the operated button 245 to the original position.

A conventional light guide plate is made of polycarbonate or acryl-based resin having high light transmittance to visible light through an injection molding process. However, they have a low modulus of elasticity, very low elastic recovery and high hardness. This makes it difficult to get a good click feel when pressing the button. Also, when a button is pressed, adjacent buttons may be erroneously operated together (interference between buttons). In addition, permanent deformation is likely to occur on the light guide plate after long-term repeated operations.

Therefore, the light guide plate 220 according to the present invention is made of highly transparent elastic materials, preferably polyurethane or silicone, which have low hardness, high modulus of elasticity, and excellent elastic recovery properties. And a high optical transmittance to provide a good tap feeling, eliminate interference between the buttons 245, and avoid permanent deformation even after repeated operations.

A plurality of buttons 245 are disposed on the upper surface 222 of the light guide plate 220 , and letters, numbers, etc. are printed on the upper surface of each button 245 . The button 245 can be made integrally with the light guide plate 220 using the same or different material as that of the light guide plate 220 . Alternatively, the button 245 may be separately formed of polycarbonate or acrylic resin and attached to the upper surface 222 of the light guide plate 220 . Each button may have any shape, such as cylindrical or elliptical cylindrical.

A plurality of protrusions 240 are formed on the lower surface 224 of the light guide plate 220 , which is opposite to the upper surface 222 of the light guide plate 220 . The protrusion 240 can be integrally formed with the light guide plate 220 by the same or different material as that of the light guide plate 220 . Alternatively, the protrusion 240 may be separately formed and connected to the lower surface 224 of the light guide plate 220 . Each protrusion 240 may have any shape, such as a truncated cone or a trapezoidal hexahedron. Each protrusion 240 is aligned under the corresponding button 245 (in the thickness direction of the keyboard assembly 200 or the direction perpendicular to the upper surface of the first PCB 260 ).

Figures 3a and 3b depict examples of protrusions according to the invention. In particular, FIG. 3 a depicts a protrusion 310 having a frusto-conical shape comprising an elliptical upper surface 312 and a lower surface 316 , and sloped side surfaces 314 . FIG. 3 b depicts a protrusion 320 , which is a trapezoidal hexahedron including a rectangular upper surface 322 and a lower surface 326 , and four trapezoidal side surfaces 324 .

The keyboard 210 has a plurality of reflective patterns 230 formed on the lower surface of the light guide plate 220 to respectively reflect a part of the light propagating in the light guide plate 220 toward the corresponding buttons 245 . If necessary, a reflective pattern 230 may be formed on the upper surface of the light guide plate 220 . Each reflective pattern 230 is formed at and around a corresponding protrusion 240 provided just below a corresponding button 245 to uniformly illuminate the button. In the complete keyboard 210, the density and size of the reflective patterns disposed close to the light emitting device 290 are different from those of the reflective patterns disposed away from the light emitting device 290, so as to uniformly adjust the overall amount of light emitted from the upper side of the light guide plate 220. distribution regardless of the distance from the light emitting device 290. For example, when the amount of light emitted from a position adjacent to the light emitting device 290 increases, the density of the reflective pattern adjacent to the light emitting device 290 is set to be lower. When the amount of light emitted from a position away from the light emitting device decreases, the density of the reflective pattern away from the light emitting device 290 is set to be higher. In this way, the light quantity distribution of the transmitted light, especially the brightness distribution of the button 245 as a whole can become uniform and bright.

Figure 4 depicts a reflective pattern according to the invention. The central portion 232 of the reflective pattern 230 is formed on the lower surface of the protrusion 240 , and the peripheral portion 234 of the reflective pattern 230 is formed around the protrusion 240 . As shown in the figure, the light traveling into the light guide plate 220 due to total reflection is incident on the reflective pattern 230 . Most of the light diffusely reflected by the reflective pattern 230 toward the button 245 cannot satisfy the condition of total reflection (incident angle is smaller than the critical angle) and is emitted outside through the button 245 . In addition, the light passing through the reflective pattern 230 without diffuse reflection and a part of the diffuse reflection light meet the total reflection condition, and continuously propagates in the light guide plate 220 to help illuminate other buttons. In this way, reflective pattern 230 induces diffuse reflection and illuminates button 245 with only a portion of the incident light, while the remaining light is used to illuminate other buttons. Furthermore, reflective pattern 230 provides uniform brightness of button 245 through diffuse reflection in any direction. Preferably, the reflective pattern 230 may be formed by scribing or printing.

As shown in FIG. 2 , a central portion 232' (represented by a plurality of hollow triangles) of the reflective pattern 230 may be formed between the light guide plate 220 and the protrusion 240 instead of being formed on the lower surface of the protrusion 240. Referring to FIG.

The switch board 250 includes a first PCB 260 and a dome sheet 270 .

The first PCB 260 has a plurality of conductive contact parts 265 formed on its upper surface, and the conductive contact parts 265 constitute switches 265 and 275 together with corresponding round covers 275 . Switches 265 and 275 are aligned under corresponding protrusions 240 .

The dome sheet 270 is connected to the upper surface of the first PCB 260 and has a plurality of hemispherical conductive domes 275 that completely cover the corresponding contact parts 265 .

When the user presses one of the buttons 245 , the portion of the keyboard 210 located under the pressed button 245 is deformed toward the switch plate 250 . As a result, one of the protrusions 240 corresponding to the deformed portion presses the corresponding dome 275 , and the dome 275 then makes electrical contact with the corresponding contact member 265 .

The second PCB 280 is connected to the periphery of the lower surface 224 of the light guide plate 220 . The light emitting device 290 is installed on the upper surface of the second PCB 280 , and the light emitting surface of the light emitting device 280 faces the side surface of the light guide plate 220 . Light emitted from the light emitting device through the side surface is coupled into the inside of the light guide plate 220 . The second PCB 280 can be made of a conventional flexible PCB (FPCB), and the light emitting device can be a conventional LED.

Figures 5a, 5b and 5c depict examples of light emitting devices according to the invention. In particular, FIG. 5 a is a front view illustrating the light emitting device 410 disposed at the center of the side surface of the light guide plate 401 . FIG. 5 b is a front view illustrating the light emitting device 420 disposed at the corner of the light guide plate 402 . FIG. 5c is a front view depicting spaced apart first and second lighting devices 430 and 435 disposed on the side surface of the light guide plate 403 and showing a plurality of buttons connected to the light guide plate 403 .

As shown in the figure, the number and position of light emitting devices according to the present invention can be selectively determined.

6 is a sectional view illustrating a keyboard assembly according to a second embodiment of the present invention. Except for the shape of the light guide plate 220' and the position of the light emitting device 290', the keyboard assembly 200' has the same structure as the keyboard assembly 200 shown in FIG. 2 . Therefore, the same components are given the same reference numerals and repeated descriptions are omitted to avoid redundancy.

The light guide plate 220' is generally a square plate and guides light coupled inside it. The peripheral portion 226 of the light guide plate 220' extends toward the upper surface of the PCB 260 with a slope.

At least one light emitting device 290' is installed on the upper surface of the PCB 260, and the light emitting surface of the light emitting device 290' faces the side surface of the inclined portion 226 of the light guide plate 220'. The light emitted from the light emitting device 290' is coupled into the interior of the light guide plate 220' through the side surface of the light guide plate 220'.

Compared with the above-mentioned first embodiment, the advantage of the second embodiment is that the shape of the light guide plate 220' is improved, so that a flexible PCB for the wiring of the light emitting device 290' is not required, and thus can be obtained in a more economical manner. Keyboard assembly 200'.

7 is a sectional view illustrating a keyboard assembly according to a third embodiment of the present invention. The keyboard assembly 200" has the same structure as the keyboard assembly 200' shown in FIG. 6 except for the shape of the light guide plate 220". Therefore, the same components are given the same reference numerals and repeated descriptions are omitted to avoid redundancy.

The light guide plate 220 ″ has a square plate shape with a constant thickness, and light is coupled therein. The peripheral portion 226 ′ of the light guide plate 220 ″ is bent so as to extend toward the upper surface of the PCB 260 . In particular, the peripheral portion 226' of the light guide plate 220" made of an elastic material such as polysiloxane can be bent at an angle shown in the drawing to adjust the light guide plate 220" and light emitting device 290' at different vertical positions. between optical connections.

The light-emitting device 290' is installed on the upper surface of the PCB 260, and the light-emitting surface of the light-emitting device 290' faces the side surface of the peripheral portion 226' of the light guide plate 220". Through the side surface of the light guide plate 220", the light emitted from the light-emitting device 290' coupled to the inside of the light guide plate 220".

As mentioned above, the beneficial effects of the keyboard and the keyboard assembly according to the present invention are: the shape and design of the elastic light guide plate and the protrusions arranged between the buttons can illuminate the buttons evenly and brightly, reduce the number of necessary light emitting devices, It becomes possible to reduce power consumption and manufacturing cost.

While the present invention has been shown and described in terms of certain preferred embodiments, it will be understood that various changes in form and details may be made therein by persons skilled in the art without departing from the spirit and scope of the invention. The spirit and scope of the present invention are defined by the claims.

Claims (21)

1. A keyboard, comprising: a light guide plate through which light travels; at least one button provided on the upper surface of the light guide plate; and At least one reflective pattern fixedly positioned relative to the light guide plate to reflect a portion of light propagating inside the light guide plate toward the button. 2. The keypad of claim 1, wherein at least one reflective pattern is partially formed on the light guide plate. 3. The keypad of claim 1, further comprising at least one protrusion formed on a lower surface of the light guide plate. 4. The keypad of claim 3, wherein the reflective pattern is formed on a lower surface of the light guide plate opposite to an upper surface of the light guide plate at and around the protrusions. 5. The keypad of claim 3, wherein a reflective pattern is formed on the protrusion. 6. The keypad of claim 3, wherein the reflective pattern is formed on a lower surface of the light guide plate opposite to an upper surface of the light guide plate between the light guide plate and the protrusion. 7. The keypad of claim 1, wherein the reflective pattern is adapted to cause diffuse reflection. 8. The keyboard as claimed in claim 1, wherein the light guide plate is made of a transparent elastic material and is adapted to return the button to an original position after the button is operated. 9. The keypad of claim 8, wherein the light guide plate is made of polyurethane or polysiloxane. 10. A keyboard assembly, comprising: A keyboard having a light guide plate through which light propagates, at least one button provided on the upper surface of the light guide plate, and at least one reflective pattern partially formed on the light guide plate to reflect a portion of the transmission toward the button light; and A switch plate having at least one switch formed on an upper surface thereof facing the keyboard, wherein when a button is pressed, a portion of the keyboard deforms toward the switch plate to actuate the switch. 11. The keypad assembly of claim 10, further comprising at least one light emitting device disposed facing a side surface of the light guide plate and adapted to couple light into an interior of the light guide plate. 12. The keypad assembly of claim 11, wherein a printed circuit board (PCB) is attached to a periphery of a lower surface of the light guide plate, and the light emitting device is mounted on an upper surface of the PCB. 13. The keypad assembly of claim 11, wherein a peripheral portion of the light guide plate extends toward an upper surface of the switch plate at an oblique angle, and the light emitting device is mounted on the upper surface of the switch plate. 14. The keypad assembly of claim 10, wherein the keypad has at least one protrusion formed on a lower surface of the light guide plate for driving the switch. 15. The keypad assembly of claim 14, wherein the reflective pattern is formed on a lower surface of the light guide plate opposite to an upper surface of the light guide plate at and around the protrusions. 16. The keypad assembly of claim 14, wherein a reflective pattern is formed on the protrusion. 17. The keypad assembly of claim 10, wherein the reflective pattern is adapted to cause diffuse reflection. 18. The keypad assembly as claimed in claim 10, wherein the light guide plate is made of a transparent elastic material and adapted to return the button to an original position after the button is operated. 19. The keypad assembly of claim 18, wherein the light guide plate is made of polyurethane or polysiloxane. 20. The keyboard assembly as claimed in claim 11, wherein the density of the reflective pattern adjacent to the light emitting device is set to be lower and the density of the reflective pattern far from the light emitting device is set to be higher so as to uniformly adjust the light from the upper surface of the light guide plate. The overall distribution of the amount of light emitted by the side. 21. A portable terminal, comprising: a switch plate with at least one switch on its upper surface; A keyboard having a light guide plate and at least one button, the light guide plate has an upper surface, a lower surface and side surfaces, the at least one button is provided on the upper surface of the light guide plate and is located above the switch; and at least one light emitting device positioned close to at least one side surface of the light guide plate, wherein The keyboard has at least one reflective pattern formed on a part of the upper surface or the lower surface of the light guide plate. The reflective pattern is located under the button and is used to reflect a part of light toward the button. The light guide plate is made of transparent elastic material.

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