CN102880313B - Optical pointing module and its light source unit - Google Patents

Abstract

An optical pointing module and a light source unit thereof are provided, wherein the light source unit is arranged on a plane and is used for providing a light beam which is inclined relative to the plane. The light source unit comprises a light emitting chip and a light transmitting package. The light emitting chip has an upper surface and a lower surface substantially parallel to the plane. The light-transmitting packaging body is in physical contact with the light-emitting chip and at least covers the upper surface of the light-emitting chip, and the light-transmitting packaging body is provided with an inclined plane which is positioned above the upper surface of the light-emitting chip and is inclined to the upper surface. In addition, the invention also provides an optical pointing module with the light source unit.

Description

Optical pointing module and its light source unit

technical field

The invention relates to an input module of an electronic device, in particular to an optical pointing module.

Background technique

The optical fingernavigation (OFN) module has the characteristics of small size, high positioning accuracy and low power consumption. It detects the movement of the finger optically to replace the traditional multi-directional buttons. It can be widely used in smart phones and media players. Devices, digital cameras, and portable electronic devices such as GPS navigation machines.

The optical pointing module is to project the light beam of a specific wavelength range emitted by a light-emitting element onto the object to be measured, so that the sensing element can clearly obtain the image of the object to be measured, and judge the object to be measured by comparing the images obtained at different time points. The moving direction and distance of the measured object. In order to simplify the manufacture, the light-emitting element and the sensing element are arranged on the same circuit board in the conventional optical pointing module. Therefore, it is necessary to deflect the light beam emitted by the light-emitting element through an optical element such as a prism, and emit it obliquely toward the The object under test, so that the sensing element can smoothly receive the image light reflected by the object under test.

However, since the prism needs a certain thickness to provide enough optical path difference to deflect the light beam to a specific angle, the overall thickness of the optical pointing module is relatively thick, making it difficult to apply to thin, light and small portable electronic devices.

Contents of the invention

An object of the present invention is to provide a light source unit that can directly provide oblique light beams without additional optical elements such as prisms.

Another object of the present invention is to provide an optical pointing module with the above light source unit, which does not require additional optical elements such as prisms to deflect light beams.

The invention discloses a light source unit, which is arranged on a plane and used to provide a light beam inclined relative to the plane. The light source unit includes a light-emitting chip and a light-transmitting packaging body. The light emitting chip has an upper surface and a lower surface substantially parallel to the plane. The light-transmitting package physically contacts the light-emitting chip and at least covers the upper surface of the light-emitting chip, and the light-transmitting package has an inclined surface above and inclined to the upper surface of the light-emitting chip.

In addition, the present invention also discloses an optical pointing module with the above-mentioned light source unit, which is used for sensing the movement of an object under test. The optical pointing module includes a use plane, a circuit board, a light source unit, and a sensing unit. Use a flat surface on which the DUT slides. The circuit board is located below the use plane and substantially parallel to the use plane. The light source unit is arranged on the circuit board and used for providing a light beam inclined relative to the use plane toward the use plane. The sensing unit is arranged on the circuit board and used for sensing the image of the object under test toward the use plane.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

1 is a cross-sectional view of an optical pointing module according to a first embodiment of the present invention;

2 is a cross-sectional view of a light source unit according to a first embodiment of the present invention;

3 is a schematic diagram of a light source unit according to a first embodiment of the present invention;

4 is a cross-sectional view of an optical pointing module according to a second embodiment of the present invention;

5 is a partial cross-sectional view of a light source unit according to a second embodiment of the present invention.

Among them, reference signs

detailed description

The optical pointing module of the present invention can sense the point-touch movement of an object to be measured, and provide a corresponding movement signal to the electronic device using the optical pointing module. FIG. 1 is a first embodiment of the optical pointing module of the present invention. The optical pointing module 50 mainly includes a use plane 51 , a circuit board 52 , a sensing unit 54 , and a light source unit 40 .

The use plane 51 allows the object under test 60 to touch or slide in any direction on its upper surface. In this embodiment, a finger is taken as an example of the object under test 60 , but it is not limited to this in actual implementation. The circuit board 52 is located below the use plane 51 and separated from the use plane 51 by a predetermined distance, and both are substantially parallel. The light source unit 40 is disposed on the upper surface of the circuit board 52 and is used for emitting a light beam inclined relative to the upper surface of the use plane 51 toward the use plane 51 .

As shown in FIG. 2 , the light source unit 40 includes a light emitting chip 44 and a transparent package 42 . The light emitting chip 44 has an upper surface 441 and a lower surface 442 substantially parallel to each other. Specifically, the light emitting element 44 may be a Vertical-Cavity Surface Emitting Laser (Vertical-Cavity Surface Emitting Laser, VCSEL) chip. The light-transmitting package 42 is in physical contact with the light-emitting chip 44 and covers the upper surface 441 and all sides of the light-emitting chip 44 . The transparent package 42 has a bottom surface 424 substantially parallel to the bottom surface 442 of the light emitting chip 44 . In this embodiment, the light-transmitting package 42 encapsulates the light-emitting chip 44 in an airtight manner, so as to protect the light-emitting chip 44 from being damaged or oxidized to affect light-emitting characteristics.

It should be noted that the transparent package 42 has an inclined surface 422 above the upper surface 441 of the light-emitting chip 44 , and the inclined surface 422 is inclined to the upper surface 441 . Specifically, the incident angle θ1 of the slope 422 relative to the upper surface 441 is between 5 degrees and 25 degrees. When the light emitted upward by the light-emitting chip 44 enters the light-transmitting package 42 , it will be refracted when encountering the slope 422 . After being refracted by the slope 422 , the traveling direction I2 of the light will form a refraction angle θ2 with the normal direction I1 of the upper surface 441 of the light emitting chip 44 . In detail, as shown in FIG. 3 , after the light of the light-emitting chip 44 is emitted upward from its upper surface 441 , it will be incident on the slope 422 at the same angle as the incident angle θ1, and due to the refractive index of the upper and lower sides of the slope 422 According to the law of refraction, the light will be emitted from the inclined surface 422 at the refraction angle θ2. The refraction angle θ2 is between 7 degrees and 40 degrees.

In addition, in another embodiment of the present invention, without considering the hermetic packaging of the light-emitting chip 44, the light-transmitting package 42 may only retain the projected portion directly above the upper surface 441 of the light-emitting chip 44, and The above-mentioned refraction function is achieved by the slope 422 .

As shown in FIG. 1 , the sensing unit 54 is disposed on the circuit board 52 and senses the image of the object under test 60 toward the use plane 51 . The sensing unit 54 can be a complementary metal oxide semiconductor (CMOS) image sensing element, but not limited thereto. The sensing element 54 is used for receiving the reflected light of the object under test 60 on the upper surface of the use plane 51 and converting the light into a corresponding electrical signal.

In addition, the optical pointing module of this embodiment further includes a light shield 56 covering the sensing unit 54 . The light shield 56 has a through hole 562 through which the beam reflected by the use plane 51 passes. By disposing the light shield 56 on the sensing unit 54 , other ambient light can be prevented from being received by the sensing unit 54 .

As shown in FIG. 4 , the second embodiment of the optical pointing module of the present invention is substantially the same as the first embodiment, except for the light source unit 70 . As shown in FIG. 5 , the light source unit 70 further includes a substrate 76 physically contacting the lower surface 742 of the light emitting chip 74 . The substrate 76 has a first electrode layer 761 connected to the light-emitting chip 74, an insulating layer 762 located below the first electrode layer 761, and an insulating layer 762 located below the insulating layer 762 and electrically connected to the first electrode layer 761. The second electrode layer 763. The first electrode layer 761 is electrically connected to the second electrode layer 763 by passing through or bypassing the insulating layer 762 , so that the second electrode layer 763 is electrically connected to the circuit board of the electronic device in a surface-adhesive manner. Moreover, the substrate 76 cooperates with the light-transmitting package body 72 to hermetically encapsulate the light-emitting chip 74 to protect the light-emitting chip 74 from being damaged or oxidized to affect light-emitting characteristics.

To sum up, the above-mentioned embodiment provides by directly forming the slope 422 , 722 for refracting light on the light-transmitting package 42 , 72 , and through the light-transmitting package 42 , 72 below the slope 422 , 722 Different optical path differences can achieve the effect of refracting light without using additional prisms. In this way, not only can the light-emitting chips 44, 74 be hermetically sealed to protect the light-emitting chips 44, 74, but also the function of light refraction can be provided at the same time.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (6)

1. An optical pointing module, in order to sense the movement of an object to be measured, is characterized in that, this optical pointing module comprises: a plane for the object to be tested to slide on; a circuit board located below and parallel to the use plane; A light source unit is arranged on the circuit board and is used to provide a light beam inclined relative to the use plane toward the use plane. The light source unit includes a light-emitting chip and a light-transmitting package; the light-emitting chip has a An upper surface and a lower surface of the light-emitting package, the light-transmitting package physically contacts the light-emitting chip and at least covers the upper surface of the light-emitting chip, and the light-transmitting package has an upper surface located above the light-emitting chip and inclined to the upper surface an inclined surface, the inclined surface is inclined at an angle between 5 degrees and 25 degrees relative to the upper surface; and a sensing unit, arranged on the circuit board and used for sensing the image of the object under test toward the use plane; A shading cover arranged on the sensing unit, the shading cover has a through hole through which the light beam reflected by the use plane passes. 2 . The optical pointing module according to claim 1 , wherein the light-transmitting package covers the upper surface of the light-emitting chip, and the light-transmitting package has a bottom surface parallel to the lower surface. 3. The optical pointing module according to claim 2, wherein the light-emitting package hermetically encapsulates the light-emitting chip. 4. The optical pointing module according to claim 1, wherein the light source unit further comprises a substrate physically contacting the lower surface of the light-emitting chip, the substrate having a first electrode layer connected to the light-emitting chip, a An insulating layer under the first electrode layer, and a second electrode layer under the insulating layer and connected to the first electrode layer. 5 . The optical pointing module according to claim 4 , wherein the circuit board cooperates with the light-transmitting package body to hermetically package the light-emitting chip. 6 . The optical pointing module according to claim 1 , wherein the light-emitting chip is a vertical cavity surface-emitting laser chip.