TECHNICAL FIELD

The present application relates to the field of optical fingerprint technologies, and in particular, to an optical fingerprint identification apparatus and an electronic device.

BACKGROUND

With the advent of the era of a full-screen mobile phone, the application of an under-display fingerprint identification apparatus is more and more widely, among which an under-display optical fingerprint identification apparatus is most popular. At present, the under-display optical fingerprint identification apparatus that enjoys mass production in the industry mainly adopts two solutions. One is to adopt a small hole imaging. In actual industrial production, the size of the small hole cannot be further reduced, thereby limiting improvement of resolution of a fingerprint image. Besides, the small hole only allows incident light in the perpendicular direction to enter, failing to provide sufficient light which causes a relatively limited imaging signal, and affecting the quality of the fingerprint image. The other is to adopt an optical lens, which uses a spherical or aspherical lens for converging light and imaging. Under the development trend of sliming the mobile phone, there is a short distance from a finger-pressing screen surface of the mobile phone to a fingerprint acquisition region of an optical chip, and a total optical thickness of the optical lens is small. Therefore, a fingerprint acquisition area is very limited, failing to perform large-area fingerprint acquisition, which affects performance of the fingerprint identification apparatus.

Therefore, how to improve the performance of the under-display optical fingerprint identification apparatus becomes an urgent problem to be solved.

SUMMARY

An embodiment of the present application provides an optical fingerprint identification apparatus and an electronic device, which may improve performance of the optical fingerprint identification apparatus.

In a first aspect, provided is an optical fingerprint identification apparatus, including:

a light detection array;

a filter layer, disposed above the light detection array, for filtering out an optical signal of a non-target band, and transmitting an optical signal of a target band, where the filter layer is integrated with the light detection array in a photosensor chip;

a first light blocking layer formed above the filter layer, where the first light blocking layer is provided with a plurality of light passing holes;

a first microlens array disposed above the first light blocking layer,

where the first microlens array is configured to converge an optical signal to the plurality of light passing holes of the first light blocking layer, and the optical signal is transmitted to the light detection array through the plurality of light passing holes of the first light blocking layer.

In a technical solution of an embodiment of the present application, the first light blocking layer is grown on the light detection array as a whole, and the plurality of light passing holes are disposed on the first light blocking layer, the optical signal is converged by the first microlens array to the plurality of light passing holes, and the optical signal is transmitted to the light detection array through the plurality of light passing holes for optical fingerprint acquisition. So a thickness of the fingerprint identification apparatus is reduced while large-area and high-resolution fingerprint identification image is achieved; and the filter layer is integrated with the light detection array in the photosensor chip, which may further reduce the thickness of the fingerprint identification apparatus, thereby improving the performance of the optical fingerprint identification apparatus.

In a possible implementation, the optical fingerprint identification apparatus further includes: a first medium layer and a second medium layer;

the first medium layer is grown on a surface of the filter layer;

the first light blocking layer is grown on a surface of the first medium layer; and

the second medium layer is grown on a surface of the first light blocking layer and fills the plurality of light passing holes of the first light blocking layer.

In a possible implementation, all of an upper surface of the first microlens array is a light-converging region, and the light-converging region of the first microlens array covers a photosensitive region of the light detection array.

In a possible implementation, the first microlens array includes a plurality of microlenses, and the light detection array includes a plurality of pixel units,

where a first microlens in the plurality of microlenses of the first microlens array is configured to converge a first optical signal from above the first microlens to a first light passing hole corresponding to the first microlens in light passing holes of the first light blocking layer, and the first optical signal is transmitted to a first pixel unit corresponding to the first microlens in the plurality of pixel units through the first light passing hole.

In a possible implementation, the optical signal is an optical signal in a first specific direction, a line direction of an optical center of the first microlens and a center of the first light passing hole is the same as or similar to the first specific direction, and a line direction of the center of the first light passing hole and a center of the first pixel unit is the same as or similar to the first specific direction.

In a possible implementation, the first specific direction is perpendicular to the light detection array.

In a possible implementation, the first specific direction is oblique to the light detection array.

In a possible implementation, a ratio of an area of an orthographic projection of the first microlens on the light detection array to an area of the first pixel unit is greater than 70%.

In a possible implementation, the first microlens is a quadrangular microlens.

In a possible implementation, an orthographic projection of the first microlens on the light detection array overlaps with the first pixel unit.

In a possible implementation, an upper surface of the first microlens is a spherical surface or an aspherical surface.

In a possible implementation, the light passing hole is a circular hole having a diameter less than 10 μm.

In a possible implementation, the optical fingerprint identification apparatus includes a plurality of layers of the first light blocking layer.

In a possible implementation, the second medium layer is disposed both between the plurality of layers of the first light blocking layer and between the first light blocking layer disposed on a topmost layer and the first microlens array, and the first light blocking layer and the second medium layer are sequentially grown by a growth process; and

the second medium layer fills the plurality of light passing holes of the first light blocking layer.

In a possible implementation, a diameter of the light passing hole of the first light blocking layer on an upper layer is greater than a diameter of the light passing hole of the first light blocking layer on a lower layer.

In a possible implementation, the optical signal is an optical signal in a second specific direction, a line direction of a center of a light passing hole of the first light blocking layer on the upper layer and a center of a corresponding light passing hole of the first light blocking layer on the lower layer is the same as or similar to the second specific direction; and

a line direction of the center of a light passing hole of the first light blocking layer on the upper layer and a center of a corresponding pixel unit in the light detection array is the same as or similar to the second specific direction.

In a possible implementation, a wavelength range of the target band includes 350-700 nm and/or 800-1000 nm.

In a possible implementation, a thickness of the filter layer is smaller than or equal to 20 μm.

In a possible implementation, the optical fingerprint identification apparatus further includes a circuit board electrically connected with a light detection portion of the optical fingerprint identification apparatus through an electrical connection apparatus.

In a possible implementation, the light detection portion is provided with a metal pad, and the electrical connection apparatus is electrically connected with the optical fingerprint identification apparatus through the metal pad.

In a possible implementation, the circuit board is a flexible circuit board, and the electrical connection apparatus is a solder, an anisotropic conductive film or a metal connection apparatus.

In a possible implementation, the circuit board is a printed circuit board, and the electrical connection apparatus is a wire bonding apparatus.

In a possible implementation, the printed circuit board is disposed below the light detection portion, or parallel with the light detection portion.

In a second aspect, an electronic device is provided, including: a display screen and the optical fingerprint identification apparatus in the first aspect or any possible implementation of the first aspect, where the optical fingerprint identification apparatus is disposed below the display screen.

