CN114765098A

CN114765098A - Backlight module for keyboard keys

Info

Publication number: CN114765098A
Application number: CN202110052959.XA
Authority: CN
Inventors: 吴志贤; 林世斌; 黄立霖; 陈湘怡
Original assignee: Sunrex Technology Corp
Current assignee: Sunrex Technology Corp
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2022-07-19

Abstract

A backlight module for keyboard keys comprises a circuit board, a plurality of light emitting elements, a light guide plate and a high reflection plate. The light guide plate comprises a first surface adjacent to the circuit board and a plurality of through holes for the light-emitting elements to penetrate through. The first surface is uneven to form a microstructure, so that light irradiated on the first surface generates a diffusion phenomenon. The high reflection plate includes an outer reflection layer using a reflective material. When the light emitted by the light-emitting component reaches the outer reflecting layer, only part of the light can penetrate through the outer reflecting layer, and the rest of the light is reflected to be emitted to the first surface. The invention can uniformly radiate light through the outer reflecting layer and the first surface. In addition, the circuit board, the light guide plate and the high reflection plate are stacked, so that the structure is simple, light and thin.

Description

Backlight module for keyboard keys

Technical Field

The present invention relates to an input device, and more particularly, to a backlight module for a keypad.

Background

A typical keyboard includes a circuit board, a plurality of touch switches disposed on a top surface of the circuit board, and a plurality of key caps respectively moving relative to the touch switches to trigger the touch switches. Various characters are drawn on the top surfaces of the keycaps in a pigment coating mode, so that a user can conveniently recognize and know the meanings during operation. In order to make the user use the keyboard even in a dark environment, a keyboard having a backlight module has been developed in recent years. The keyboard with the backlight module is similar to the common keyboard, but the characters are not drawn in a pigment coating mode, the part of the keycap corresponding to the characters is transparent, and the rest part of the keycap is opaque. In addition, a backlight module is arranged between the circuit board and the keycap, so that light rays generated by the backlight module penetrate through the keycap corresponding to the characters. Therefore, even in a dark environment, a user can recognize the characters on the keycap through the light rays generated by the backlight module so as to operate smoothly.

However, a general backlight module usually includes a plurality of light emitting elements respectively corresponding to the key caps, and when each light emitting element illuminates the corresponding key cap, only a part of the characters is brighter and the other parts of the characters are darker and lighter due to excessive concentration of emitted light. This situation can lead to unsightly characters or even difficult recognition, which can lead to poor user experience and prevent product sales.

Disclosure of Invention

The invention aims to provide a backlight module for keyboard keys, which can uniformly emit light and has a simple and light structure.

The invention relates to a backlight module for keyboard keys, which comprises a circuit board, a plurality of light-emitting elements, a light guide plate and a high-reflection plate.

The light-emitting piece is arranged on the circuit board and protrudes out of one side of the circuit board. The light guide plate is stacked on one side of the circuit board, where the light-emitting piece is arranged. The light guide plate comprises a first surface adjacent to the circuit board, a second surface opposite to the first surface, and a plurality of through holes which penetrate from the first surface to the second surface and are used for the light-emitting elements to penetrate through. The first surface is uneven to form a microstructure, so that light irradiated on the first surface generates a diffusion phenomenon. The high reflection plate is stacked on one side of the light guide plate opposite to the circuit board and shields the through holes. The high reflecting plate comprises a third surface adjacent to the light guide plate, a fourth surface opposite to the third surface, and an outer reflecting layer coated on the fourth surface. The outer reflecting layer is made of a reflective material, so that when the light emitted by the light-emitting element reaches the outer reflecting layer, only part of the light can penetrate through the outer reflecting layer, and the rest of the light is reflected to emit to the first surface.

The backlight module for the keyboard keys further comprises a reflecting sheet which is stacked between the light guide plate and the circuit board, and the reflecting sheet reflects light rays from the light guide plate.

The backlight module for the keyboard keys further comprises an inner reflecting layer coated on the third surface, wherein the inner reflecting layer is made of a reflective material, so that when light emitted by the light emitting element reaches the inner reflecting layer, only part of the light can penetrate through the inner reflecting layer, and the rest of the light is reflected to be emitted to the first surface.

The invention relates to a backlight module for keyboard keys, wherein a light emitting element is a light emitting diode.

The invention relates to a backlight module for keyboard keys, wherein an outer reflecting layer of a high reflecting plate is printed by white ink.

The invention relates to a backlight module for keyboard keys, wherein an inner reflecting layer of a high reflecting plate is printed by white ink.

The invention has the beneficial effects that: the light emitted by the light emitting element is repeatedly ejected back and forth between the light guide plate and the high reflection plate through the outer reflection layer, and the micro-structure formed by the first surface generates a diffusion phenomenon, so that the light is uniformly emitted. Moreover, the circuit board, the light guide plate and the high reflection plate are stacked, so that the keyboard is simple, light and thin in structure and beneficial to reducing the weight and the thickness of the keyboard.

Drawings

FIG. 1 is an exploded perspective view of one embodiment of a backlight module for a keypad of the present invention;

FIG. 2 is a partially cut-away schematic view of a keyboard to which the embodiment is applied;

FIG. 3 is an enlarged view of a portion of FIG. 2;

FIG. 4 is a schematic view similar to FIG. 3 illustrating the direction of travel of light.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Referring to fig. 1, 2 and 3, an embodiment of the backlight module for the keypad key of the present invention includes a circuit board 1, a plurality of light emitting elements 2, a reflective sheet 3, a light guide plate 4, and a high reflective plate 5.

The light emitting member 2 is disposed on the circuit board 1 and protrudes from one side of the circuit board 1. The reflective sheet 3, the light guide plate 4 and the high reflective plate 5 are sequentially stacked on one side of the circuit board 1 where the light emitting element 2 is disposed.

In the present embodiment, the Light emitting element 2 is a Light-emitting diode (LED), and the design has the advantages of being easily controlled by a signal and being capable of generating white Light, monochromatic Light or mixing other color lights (for example, using an RGB color mode).

The Light guide plate 4 (LGP) includes a first surface 41 adjacent to the circuit board 1, a second surface 42 opposite to the first surface 41, and a plurality of through holes 43 penetrating from the first surface 41 to the second surface 42 and for the Light emitting elements 2 to pass through. The first surface 41 is uneven to form a microstructure.

The high reflection plate 5 is stacked on the side of the light guide plate 4 opposite to the circuit board 1 and shields the through hole 43. The high reflection plate 5 includes a third surface 51 adjacent to the light guide plate 4, a fourth surface 52 opposite to the third surface 51, an inner reflection layer 53 coated on the third surface 51, and an outer reflection layer 54 coated on the fourth surface 52. Both the inner reflective layer 53 and the outer reflective layer 54 are made of reflective materials.

In the embodiment, the inner reflective layer 53 and the outer reflective layer 54 are both printed by using white ink, and the white ink may be titanium dioxide (refractive index is about 2.5-2.7) with good reflective performance, but this is only an example, and those skilled in the art may also use other reflective materials as required. In addition, the material used between the third surface 51 and the fourth surface 52 is a material that can transmit light, such as a plastic sheet made of PET, but those skilled in the art can also use other materials that can transmit light as required, and should not be limited thereto.

When the light emitting member 2 emits light, the light is emitted from the through hole 43 toward the high reflection plate 5 and travels along a path similar to the arrow shown in fig. 4. Specifically, light sequentially passes through the inner reflective layer 53 and the outer reflective layer 54. When the light reaches the inner reflective layer 53, only a portion of the light passes through the inner reflective layer 53, and the rest of the light is reflected to the first surface 41. The light transmitted through the inner reflective layer 53 further reaches the outer reflective layer 54. When the light reaches the outer reflective layer 54, only a portion of the light passes through the outer reflective layer 54, and the rest of the light is reflected toward the first surface 41. Since the first surface 41 is formed with the micro-structure, the light irradiated on the first surface 41 will generate a diffusion phenomenon. The diffused light is redirected at various angles toward the high reflection plate 5. Therefore, the light emitted from the light emitting element 2 repeatedly bounces back and forth and is uniformly distributed in the light guide plate 4 and the high reflection plate 5 until being transmitted by the outer reflection layer 54.

It should be noted that, since light may also penetrate through the first surface 41, the reflective sheet 3 can reflect the light from the light guide plate 4, so that the light is returned to the light guide plate 4 and the high reflective plate 5, thereby improving the utilization rate of the light.

Therefore, the keyboard of the embodiment can uniformly emit light, so that the problem of uneven brightness of characters on the keycaps can be solved by applying the keyboard of the embodiment, and the experience of users is promoted and the sale is facilitated.

In addition, since the circuit board 1, the reflective sheet 3, the light guide plate 4 and the high reflective plate 5 are stacked in parallel in this embodiment, the structure of this embodiment is very simple and light. The keyboard of the embodiment can reduce the weight and the thickness to meet the use requirements of users, further improve the experience of the users and facilitate the sale.

In summary, the backlight module for keyboard keys of the present invention can uniformly emit light through the outer reflective layer 54 and the first surface 41. Moreover, the circuit board 1, the light guide plate 4 and the high reflection plate 5 are stacked, so that the structure is relatively simple and light, which is beneficial to reducing the weight and thickness of the keyboard, thereby achieving the purpose of the present invention.

Claims

1. The utility model provides a keyboard is backlight module for button, contains circuit board, a plurality of illuminating part, and light guide plate, its characterized in that:

the light-emitting piece is arranged on the circuit board and protrudes out of one side of the circuit board;

the light guide plate is stacked on one side of the circuit board, where the light-emitting element is arranged, and comprises a first surface adjacent to the circuit board, a second surface opposite to the first surface, and a plurality of through holes which penetrate from the first surface to the second surface and are provided for the light-emitting element to penetrate through, wherein the first surface is uneven to form a microstructure, so that light irradiated on the first surface is diffused;

the high-reflection plate is stacked on one side, opposite to the circuit board, of the light guide plate and shields the through holes, the high-reflection plate comprises a third surface, a fourth surface and an outer reflection layer, the third surface is adjacent to the light guide plate, the fourth surface is opposite to the third surface, the outer reflection layer is coated on the fourth surface, the outer reflection layer is made of reflective materials, when light emitted by the light emitting element reaches the outer reflection layer, only part of the light penetrates through the outer reflection layer, and the rest of the light is reflected to the first surface.

2. The backlight module for keyboard keys of claim 1, wherein: the light guide plate is arranged on the circuit board, and the circuit board is arranged on the light guide plate.

3. The backlight module for keyboard keys of claim 1, wherein: the high-reflection plate also comprises an internal reflection layer coated on the third surface, and the internal reflection layer is made of a reflective material, so that when the light emitted by the light-emitting element reaches the internal reflection layer, only part of the light can penetrate through the internal reflection layer, and the rest of the light is reflected to be emitted to the first surface.

4. The backlight module for keyboard keys of claim 1, wherein: the light emitting component is a light emitting diode.

5. The backlight module for keypad of claim 1, wherein: the outer reflecting layer of the high reflecting plate is printed by white ink.

6. The backlight module for keyboard keys according to claim 3, wherein: the inner reflecting layer of the high reflecting plate is printed by white ink.