TWI862127B - Sensor module with backlight - Google Patents

Abstract

A sensor module with backlight includes a circuit carrier board, a sensing unit, a light-emitting part, and a light-guiding plate. The circuit carrier board has a first surface and a second surface opposite to the first surface. The sensing unit is electrically fixed on the first surface. The light-emitting part is electrically fixed on the second surface. The light-guiding plate has a recess and faces the second surface. The light-emitting part is accommodated in the recess. Light emitted by the light-emitting part enters the light-guiding plate through a wall surface of the recess and exits from a periphery of the light guide plate. The circuit carrier board has a connection portion. The connection portion passes by a peripheral side of the light-guiding plate.

Description

Sensor module with backlight

The present invention relates to a sensor module, and in particular to a sensor module with a backlight.

Some sensors are designed with backlights, which can participate in the sensing of the sensor or be used as a decoration or indication of the sensor. The backlight structure is usually set under the circuit board that carries the sensing element in the sensor. The connection lines between this circuit board and the outside of the sensor (such as a flexible circuit board) often interfere with the presentation of the backlight, such as making the backlight uneven.

In view of the problems in the prior art, the purpose of the present invention is to provide a sensor module with a backlight, which improves the presentation of the backlight by arranging its connecting circuit part around the backlight structure.

According to one embodiment of the present invention, a sensor module with backlight includes a circuit carrier, a sensing unit, a light-emitting element and a light guide plate. The circuit carrier has a first surface and a second surface opposite to the first surface. The sensing unit is electrically fixed on the first surface. The light-emitting element is electrically fixed on the second surface. The light guide plate has a groove and is arranged toward the second surface. The light-emitting element is accommodated in the groove. The light emitted by the light-emitting element enters the light guide plate through the wall of the groove and is emitted from the periphery of the light guide plate. The circuit carrier has a connecting portion, which passes through a periphery of the light guide plate. In practice, the connecting portion of the circuit carrier is light-transmissive, so that the light emitted from the periphery of the light guide plate can at least partially pass through the connecting portion, thereby reducing the degree of uneven backlight. For another example, the connecting portion has a hole to reduce the degree of shielding of the light emitted from the periphery of the light guide plate by the connecting portion, which can also reduce the degree of uneven backlight. For another example, the connecting portion extends obliquely on the periphery of the light guide plate so that the connecting portion is distributed over the entire periphery, so that the connecting portion can provide a relatively uniform shading rate for the entire periphery, which can also reduce the degree of uneven backlight.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the attached drawings.

1:Sensor module

10: Shell

102: Storage tank

102a: Opening

102b: Wall

102c: bottom

104: Top surface

106: Annular light-transmitting area

108: Channel

12,32,42: Circuit board

122: Main body

122a: first surface

122b: Second surface

124,324,424:Connection part

14: Sensing unit

14a: Sensing surface

16: Luminous parts

18: Light guide plate

182: Upper surface

184: Groove

184a,184b: Wall

186:Surroundings

186a: Side

188: Lower surface

20: Protective cover

324a: hole

Dv: vertical direction

Dh: horizontal direction

S1,S2,S3: Section

FIG1 is a schematic diagram of a sensor module with backlight according to a first embodiment.

Figure 2 is an exploded view of the sensor module with backlight in Figure 1.

FIG3 is a cross-sectional view of the sensor module with backlight along line X1-X1 in FIG1.

Figure 4 is a schematic diagram of the light path emitted by the light-emitting element in Figure 3.

FIG5 is a schematic diagram showing the circuit board in the sensor module with backlight in FIG1 being stacked on the light guide plate.

FIG6 is a schematic diagram showing a circuit carrier stacked on a light guide plate according to a second embodiment.

FIG7 is a schematic diagram showing a circuit carrier stacked on a light guide plate according to a third embodiment.

Please refer to FIGS. 1 to 3 ; wherein the viewing angle of FIG. 2 is different from that of FIG. 1 . A sensor module with backlight according to a first embodiment (hereinafter referred to as sensor module 1) comprises a housing 10, a circuit carrier 12, a sensing unit 14, a light emitting element 16 (in FIG. 2 , its outline is shown by dotted lines), a light guide plate 18 and a protective cover 20. The housing 10 has a receiving groove 102, and the circuit carrier 12, the sensing unit 14, the light emitting element 16, the light guide plate 18 and the protective cover 20 are received in the receiving groove 102. The protective cover 20, the circuit carrier 12 and the light guide plate 18 are stacked in a vertical direction Dv (indicated by a double-headed arrow in the figure). A circuit is formed on the circuit carrier 12. The circuit board 12 includes a main body 122 and a connecting portion 124 extending from the main body 120. The main body 122 has a first surface 122a and a second surface 122b opposite to the first surface 122a, the first surface 122a faces the protective cover 20, and the second surface 122b faces the upper surface 182 of the light guide plate 18. The sensing unit 14 is electrically fixed on the first surface 122a, and the light-emitting element 16 is electrically fixed on the second surface 122b. The light guide plate 18 forms a groove 184 on the upper surface 182, and the light-emitting element 16 is accommodated in the groove 184. The protective cover 20 completely covers the sensing unit 14, and can provide protection for the sensing surface 14a (facing the opening 102a of the accommodating groove 102) of the sensing unit 14.

In the first embodiment, the housing 10 is light-conducting (e.g., made of a light-transmitting material). The housing 10 has a top surface 104 and an annular light-transmitting area 106 (indicated by an oblique shadow area in FIG. 1 ) located on the top surface 104; in practice, the annular light-transmitting area 106 can be realized by, for example but not limited to, selectively coating an opaque layer (e.g., printing an opaque ink) on the top surface 104. The annular light-transmitting area 106 surrounds the opening 102a of the accommodating groove 102. Please also refer to FIG. 4 (wherein the cross-section of the sensor module 1 is removed to facilitate the presentation of the light path). The light emitted by the light emitting element 16 (indicated by arrows in FIG. 4 ) enters the light guide plate 18 through the walls 184a and 184b of the groove 184 (wherein the wall 184a is the bottom wall of the groove 184, and the wall 184b is the side wall of the groove 184, and there are four of them) and then exits the light guide plate 18 from the periphery 186 of the light guide plate 18. The periphery 186 of the light guide plate 18 faces the wall 102b (i.e. the side wall) of the receiving groove 102, so that the light emitted from the periphery 186 of the light guide plate 18 enters the housing 10 through the wall 102b of the receiving groove 102. The light in the housing 10 can be emitted upward from the housing 10 through the annular light-transmitting area 106, and the emitted light can have an indication or decorative function according to the actual design.

In addition, in the first embodiment, although the light-emitting element 16 is shown as a single block in the figure, in practice, it can be a single light-emitting unit or a collection of multiple light-emitting units that are separately arranged, and each light-emitting unit can also include at least one light-emitting crystal (for example but not limited to a light-emitting diode crystal). In addition, in the first embodiment, the light-emitting element 16 simultaneously emits light to all the wall surfaces 184a and 184b of the groove 184, but in practice, it can also emit light only to the wall surface 184a (i.e., the bottom wall surface), one or more wall surfaces 184b (i.e., the side wall surface), or a combination of the wall surfaces thereof, which depends on the actual design and will not be further described. In addition, in the first embodiment, the groove 184 is located at the geometric center of the upper surface 182 (see FIG. 2 ), which helps to improve the uniformity of light emitted from the annular light-transmitting area 106. In addition, in the first embodiment, the sensor module 1 uses a light-emitting element 16 (with a groove 184) to provide a light source, but in practice, multiple light-emitting elements (with multiple grooves 184) can also be used to provide a light source, which will not be described separately. In addition, in practice, a reflective structure can be added to the lower surface 188 (relative to the upper surface 182) of the light guide plate 18, such as attaching a reflective sheet or coating the lower surface 188 to form a reflective layer, which can increase the light utilization rate and the uniformity of light emitted (from the periphery 186 of the light guide plate 18).

Please refer to Figures 2 and 3. The circuit board 12 is electrically connected to the outside through its connecting portion 124. The housing 10 has a channel 108 that connects the accommodating tank 102 and the outside of the housing 10. The connecting portion 124 passes through the channel 108. In the first embodiment, the channel 108 is located at the bottom 102c of the accommodating tank 102 (i.e., exposed on the bottom wall); but in practice, the channel 108 can also be located on the side wall of the accommodating tank 102 (i.e., exposed on one of the side walls, i.e., the wall 102b), such as the place indicated by the dotted frame in Figure 3.

In addition, in the first embodiment, the connecting portion 124 will pass through a periphery 186a of the light guide plate 18 (from the perspective of FIG. 3 , the periphery 186 on the right side), so the connecting portion 124 will shield the light emitted from the periphery 186a. By designing the connecting portion 124 (e.g., material, shape, etc.), the influence of the aforementioned shielding on the uniformity of light emitted from the annular light-transmitting area 106 can be reduced. Please also refer to FIG. 5 , which is a schematic diagram of the circuit board 12 stacked on the light guide plate 18. In the first embodiment, the connecting portion 124 is light-transmitting (e.g., made of light-transmitting material), which can increase the ratio of light penetrating the connecting portion 124, thereby reducing the shielding effect of the connecting portion 124. But in practice this is not the limit.

For example, please refer to FIG. 6. In a second embodiment, the connection portion 324 of the circuit board 32 has at least one hole 324a (two holes in this embodiment). The light emitted from the periphery 186a can pass through the connection portion 324 through the hole 324a, thereby reducing the shielding effect of the connection portion 124. In practice, without affecting the circuit routing, the connection portion 324 can have more holes, and their positions are not limited to alignment. In addition, the connection portion 324 itself must also be light-transmissive (for example, made of light-transmissive material), further reducing the shielding effect of the connection portion 324.

For another example, please refer to FIG. 7. In a third embodiment, the connection portion 424 of the circuit board 42 extends obliquely on the periphery 186a relative to the vertical direction Dv. In the horizontal direction Dh (perpendicular to the vertical direction Dv), although the influence range of the connection portion 424 on the periphery 186a is increased (compared to those shown in FIG. 5 and FIG. 6), light still emerges from the periphery 186a in each section S1, S2, S3 (shown in the figure with a dotted frame). This structural configuration helps to reduce the unevenness of light emitted from the annular light-transmitting area 106 (see FIG. 1) (i.e., there will be no obvious and sharp light and dark phenomenon). Furthermore, in this embodiment, the connecting portion 424 is disposed obliquely along the entire periphery 186a, that is, the connecting portion 424 extends more toward the horizontal direction Dh, which can increase the light transmittance of each segment S1, S2, and S3, thereby helping to further reduce the unevenness of light emitted from the annular light-transmitting area 106. In addition, according to the teachings of the aforementioned first and second embodiments, the connecting portion 424 can also be made of a light-transmitting material, or/and a through hole can be formed in the connecting portion 424, which also helps to reduce the shielding effect of the connecting portion 424, which will not be elaborated further.

In addition, please refer to FIG. 2. In the first embodiment, the circuit carrier 12 is implemented as a single board, such as but not limited to a flexible circuit board. In practice, the circuit carrier 12 can also be a component. For example, the main body 122 of the circuit carrier 12 is implemented as a printed circuit board, and the connection part 124 of the circuit carrier 12 is implemented as a flexible circuit board. The two can be directly fixedly connected or removably connected via a connector.

In addition, in actual applications, the sensing unit 14 of the sensor module 1 can be a fingerprint recognition element, and the material or structure of the protective cover 20 is modified according to the recognition principle of the fingerprint recognition element (for example, obtaining fingerprints by optical, capacitive or other methods). At this time, the sensor module 1 is a fingerprint recognition device; in practice, it can be integrated into the keyboard.

The above is only the preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the patent application of the present invention shall fall within the scope of the present invention.

1:Sensor module

10: Shell

102: Storage tank

102a: Opening

102b: Wall

102c: bottom

104: Top surface

106: Annular light-transmitting area

108: Channel

12: Circuit board

122: Main body

122a: first surface

122b: Second surface

124: Connection part

14: Sensing unit

14a: Sensing surface

16: Luminous parts

18: Light guide plate

182: Upper surface

184: Groove

184a,184b: Wall

186:Surroundings

186a: Side

188: Lower surface

20: Protective cover

Dv: vertical direction

Dh: horizontal direction

Claims (10)

A sensor module with backlight includes: a circuit carrier having a first surface and a second surface opposite to the first surface; a sensing unit electrically fixed on the first surface; a light-emitting element electrically fixed on the second surface; and a light guide plate having a groove, the light guide plate is arranged toward the second surface, the light-emitting element is accommodated in the groove, the light emitted by the light-emitting element enters the light guide plate through the wall of the groove and is emitted from the periphery of the light guide plate, and the circuit carrier has a connecting portion, and the connecting portion passes through a periphery of the light guide plate. A sensor module with backlight as described in claim 1, wherein the connecting portion of the circuit board is light-transmissive. A sensor module with backlight as described in claim 1, wherein the connecting portion of the circuit board has a hole. The sensor module with backlight as described in claim 1, wherein the circuit carrier and the light guide plate are stacked in a vertical direction, and the connecting portion of the circuit carrier extends obliquely relative to the vertical direction at the periphery. The sensor module with backlight as described in claim 1 further comprises a housing, wherein the housing has a receiving groove, the circuit board, the sensing unit, the light-emitting element and the light guide plate are received in the receiving groove, and the sensing surface of the sensing unit faces the opening of the receiving groove. The sensor module with backlight as described in claim 5, wherein the housing is light-conducting, the housing has a top surface and an annular light-transmitting area located on the top surface, the annular light-transmitting area surrounds the opening of the receiving groove, and the light emitted from the periphery of the light guide plate enters the housing through the wall of the receiving groove. The sensor module with backlight as described in claim 5, wherein the housing has a channel connecting the receiving slot and the outside of the housing, and the connecting portion of the circuit board passes through the channel. A sensor module with backlight as described in claim 7, wherein the channel is located at the bottom of the receiving groove. A sensor module with backlight as described in claim 1, wherein the groove is located at the geometric center of one surface of the light guide plate. The sensor module with backlight as described in claim 1, wherein the wall surface of the groove is the bottom wall surface of the groove.

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