Patent Description:
A fingerprint recognition technology is a technology of identifying an individual by using fingerprints, where a real identity of a user is verified by comparing a fingerprint collected in real time with a pre-stored fingerprint. Skin texture (including fingerprints) of each person varies in patterns, breakpoints, and intersections. In other words, fingerprints of each person are unique and unchangeable in a lifetime. As shown in <FIG>, in the prior art, a fingerprint unlock structure of a mobile terminal is disposed outside a display screen, that is, a dedicated area is disposed on a front panel of the mobile terminal to accommodate the fingerprint unlock structure. Because the fingerprint unlock structure independently occupies an area of the front panel, a large non-display area needs to be disposed on the front panel of the mobile terminal. <CIT> relates to a display screen supporting a full-screen optical fingerprint sensor. <CIT> relates to fingerprints sensors for mobile devices.

Embodiments of this application provide a display module and a mobile terminal, to increase a display size of the mobile terminal and a screen-to-body ratio.

This application provides a display module, where the display module includes a display screen and an optical fingerprint module, where the optical fingerprint module is located on a surface of the display screen away from a light-out surface and is fixedly connected to the display screen, a vertical projection of a fingerprint detection area of the optical fingerprint module on the light-out surface of the display screen is located inside a display area of the display screen, and light is able to be transmitted through the display screen to the fingerprint detection area.

In the foregoing technical solution, the optical fingerprint module is used to detect a fingerprint, and the optical fingerprint module is disposed under the display screen, so that a fingerprint can be collected when a finger presses the screen. Different from a mobile terminal in the prior art, because the optical fingerprint module is disposed under the display screen, no space of a front panel of the mobile terminal needs to be occupied, and more space can be used for disposition of the display screen, thereby increasing an area of the display screen, increasing a display size of the mobile terminal, and improving a screen-to-body ratio.

In a specific implementation solution, a display screen protective layer located on the surface of the display screen away from the light-out surface is further included, where the display screen protective layer is fixedly connected to the display screen; and a through hole is disposed at the display screen protective layer, and light is transmitted through the through hole to the fingerprint detection area. The display screen protective layer is used to protect the display screen, improving safety of the display screen.

In a specific implementation solution, the vertical projection of the fingerprint detection area on the light-out surface of the display screen is located inside a vertical projection of the through hole on the light-out surface of the display screen. This ensures that light can be transmitted to the fingerprint detection area, and improves fingerprint detection effect.

In a specific implementation solution, the optical fingerprint module is bonded to the display screen protective layer by using a bezel adhesive. The optical fingerprint module is fixedly connected to the display screen through bonding. During specific configuration, the bezel adhesive forms a frame shape, with the fingerprint detection area exposed in the middle.

In a specific implementation solution, the optical fingerprint module is bonded to the display screen by using a bezel adhesive. This ensures connection stability.

In a specific implementation solution, the optical fingerprint module is further bonded to the display screen by using an optical clear adhesive, and the optical clear adhesive is disposed in the fingerprint detection area. This further improves stability of the optical fingerprint module.

In a specific implementation solution, light transmittance of the optical clear adhesive is not less than <NUM>%. This ensures that the optical fingerprint module works reliably.

In a specific implementation solution, the optical fingerprint module includes a sensor, a packaging layer for packaging the sensor, a flexible printed circuit board connected to the sensor, and a stiffener located on a surface of the packaging layer away from the display screen, and the stiffener is fixedly connected to the packaging layer.

In a specific implementation solution, the optical fingerprint module includes a sensor, a packaging layer for packaging the sensor, a flexible printed circuit board connected to the sensor, and a U-shaped support plate, where a concave area of the support plate is fixedly connected to the support place, a bending structure is disposed on each of two side walls of the support plate, and the bending structure is bonded to the display screen protective layer.

In a specific implementation solution, the bending structure is bonded to the display screen protective layer by using a bezel adhesive.

According to a second aspect, a mobile terminal is provided, where the mobile terminal includes a housing and the display module disposed in the housing according to any one of the foregoing implementation solutions.

In the foregoing technical solutions, the optical fingerprint module is used to detect a fingerprint, and the optical fingerprint module is disposed under the display screen, so that a fingerprint can be collected when a finger presses the screen. Different from a mobile terminal in the prior art, because the optical fingerprint module is disposed under the display screen, no space of a front panel of the mobile terminal needs to be occupied, and more space can be used for disposition of the display screen, thereby increasing an area of the display screen, increasing a display size of the mobile terminal, and improving a screen-to-body ratio.

For easy understanding of the solutions in the embodiments of this application, an existing disposition manner of a fingerprint unlock structure <NUM> of a mobile terminal is first described. <FIG> shows a structure of a mobile terminal in the prior art. It can be seen from <FIG> that a display screen <NUM> and the fingerprint unlock structure <NUM> are disposed on a front panel <NUM> of the mobile terminal from top to bottom of the terminal. In this case, an area of a width d needs to be reserved on the front panel <NUM> for disposition of the fingerprint unlock structure <NUM>. As a result, a non-display area on the mobile terminal is relatively wide and an area occupied by the display screen <NUM> is relatively small. In this disposition manner, a screen-to-body ratio (screen-to-body ratio = area of a display area of the display screen <NUM>/area of the front panel <NUM>) of the mobile terminal is relatively low. This is not conducive to improving the screen-to-body ratio.

To improve the screen-to-body ratio of the mobile terminal, that is, to increase an area occupied by a display screen <NUM> without changing a front panel size of the mobile terminal, an embodiment of this application provides a display module. <FIG> is a top view of the display module, and <FIG> is a side view of the display module. The display module includes a display screen <NUM> and an optical fingerprint module <NUM>. The optical fingerprint module <NUM> is located on a surface of the display screen <NUM> away from a light-out surface and is fixedly connected to the display screen <NUM>. A vertical projection of a fingerprint detection area <NUM> of the optical fingerprint module <NUM> on the light-out surface of the display screen <NUM> is located inside a display area <NUM> of the display screen <NUM>, and light is able to be transmitted through the display screen <NUM> to the fingerprint detection area <NUM>.

<FIG> is a top view of the display module. It should be noted that the display screen <NUM> is an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display screen. The display screen <NUM> includes a glass cover, an optical clear adhesive layer, a touch display module, and a protective layer that are sequentially stacked. The display screen <NUM> is a self-emissive display screen, and light emitted by the display screen <NUM> can be transmitted through the display screen <NUM>, so that the display screen <NUM> can display a picture normally. In addition, external light can also reach the display screen <NUM>, and go through the display screen <NUM> to the optical fingerprint module <NUM>.

The display screen <NUM> includes the display area <NUM> and a non-display area, and the display area <NUM> and the non-display area are areas specified on the light-out surface of the display screen <NUM>. As shown in <FIG>, a middle part of the display screen <NUM> is the display area <NUM>, and a part that encloses the display area <NUM> is the non-display area. The non-display area is a frame-shaped area used to cover wires on a display panel. In addition, to protect the display screen <NUM>, a display screen protective layer <NUM> is disposed on the surface of the display screen <NUM> away from the light-out surface, and the display screen protective layer <NUM> is fixedly connected to the display screen <NUM>. In addition, a through hole <NUM> is disposed at the display screen protective layer <NUM>. The through hole <NUM> forms a path for receiving light, reflected by a finger, that is to reach the fingerprint detection area <NUM>, and the reflected light goes through the through hole <NUM> to the fingerprint detection area <NUM>. During specific configuration, the through hole <NUM> may be in different shapes, such as round, rectangular, or triangular.

A fingerprint detection apparatus in this embodiment is the optical fingerprint module <NUM>. The optical fingerprint module <NUM> receives light reflected by a finger, and determines a fingerprint of the finger by using the reflected light. In this application, to improve the screen-to-body ratio of the mobile terminal, the optical fingerprint module <NUM> is disposed under the display screen <NUM>, that is, the optical fingerprint module <NUM> is located on the surface of the display screen <NUM> away from the light-out surface. To ensure operating reliability of the optical fingerprint module <NUM>, the fingerprint detection area <NUM> of the optical fingerprint module <NUM> is located inside the display area <NUM> of the display screen <NUM>. During specific configuration, the following condition is met: The vertical projection of the fingerprint detection area <NUM> of the optical fingerprint module <NUM> on the light-out surface of the display screen <NUM> is located inside the display area <NUM> of the display screen <NUM>. The fingerprint detection area <NUM> of the optical fingerprint module <NUM> is an area used to detect a fingerprint on the optical fingerprint module <NUM>, and is a sensing area of a sensor <NUM> of the optical fingerprint module <NUM>. During use, light emitted by the display screen <NUM> hits a fingerprint and is reflected by the fingerprint, and the reflected light can be transmitted through the display screen <NUM> to the fingerprint detection area <NUM> of the optical fingerprint module <NUM>, so that optical fingerprint module <NUM> can work normally.

Referring to <FIG>, a dashed-line box in <FIG> shows the fingerprint detection area <NUM> of the optical fingerprint module <NUM>. <FIG> is a top view of the display module. The view is a view of the display module seen from above, and the light-out surface of the display screen <NUM> is vertical to an observation direction of the view. Therefore, a structure shown in <FIG> displays different components in a vertical direction on one plane, that is, the light-out surface, the fingerprint detection area <NUM>, and the like are located on the same plane. Therefore, the dashed-line box representing the fingerprint detection area <NUM> may be understood as a position of the vertical projection on the light-out surface. It can be seen from <FIG> that the entire vertical projection falls inside the display area <NUM>. In other words, the fingerprint detection area <NUM> is located inside the display area <NUM> of the display screen <NUM>. Referring to <FIG>, light reflected by a fingerprint can be transmitted to the fingerprint detection area <NUM>.

In a specific implementation solution, the vertical projection of the fingerprint detection area on the light-out surface of the display screen <NUM> is located inside a vertical projection of the through hole <NUM> on the light-out surface of the display screen <NUM>. This prevents the display screen protective layer <NUM> from blocking the light reflected by the fingerprint, ensures that the light can be transmitted to the fingerprint detection area, and improves fingerprint detection effect.

In addition, it should be understood that the fingerprint detection area <NUM> shown in <FIG> is in a rectangular shape, and the rectangular shape is merely a specific example of the fingerprint detection area <NUM>. The fingerprint detection area <NUM> may be in different shapes, such as round, oval, or triangular. A specific shape of the fingerprint detection area <NUM> may be determined based on an actual design.

During specific configuration, only the fingerprint detection area <NUM>, instead of an entire structure of the optical fingerprint module <NUM>, needs to be located inside the display area <NUM>. Any other structure of the optical fingerprint module <NUM> may or may not be located inside the display area <NUM>. In a specific example, as shown in <FIG>, the optical fingerprint module <NUM> includes a sensor <NUM>, a packaging layer <NUM> for packaging the sensor <NUM>, and a flexible printed circuit board <NUM> connected to the sensor <NUM>. The packaging layer <NUM> wraps the sensor <NUM>, with the fingerprint detection area <NUM> on the sensor <NUM> exposed. This not only improves safety of the sensor <NUM>, but also ensures that the sensor <NUM> can receive the light reflected by the fingerprint. The flexible printed circuit board <NUM> is connected to the sensor <NUM>, and is configured to transmit a signal detected by the sensor <NUM> to a control chip of the mobile terminal. In addition, to increase stiffness of the optical fingerprint module <NUM>, a stiffener <NUM> is further disposed for the optical fingerprint module <NUM>, and the stiffener <NUM> is fixedly connected to the packaging layer <NUM>. The stiffener <NUM> is a metal plate or a plastic plate with some support stiffness, such as a steel plate, an iron plate, an aluminum plate, or a polyvinyl chloride plate. As shown in <FIG>, the stiffener <NUM> is located on a surface of the packaging layer <NUM> away from the sensor <NUM>. To be specific, the optical fingerprint module <NUM> is assembled behind the display screen <NUM>, and the stiffener <NUM> is located on the surface of the packaging layer <NUM> away from the display screen <NUM>. During specific configuration, the packaging layer <NUM> of the optical fingerprint module <NUM> may be located inside the display area <NUM> of the display screen <NUM>, as shown in <FIG>; or may be partially located outside the display area <NUM>. This is not limited herein.

<FIG> is a schematic diagram of a mobile terminal to which the display module is applied according to this embodiment. The mobile terminal may be a common mobile terminal, such as a mobile phone or a tablet computer. Through comparison between <FIG> and <FIG>, it can be learned that for the display module provided in this embodiment, the optical fingerprint module <NUM> is disposed under the display screen <NUM>, so that no area needs to be reserved on the front panel of the mobile terminal for accommodating the optical fingerprint module <NUM>, a width of an area originally used for disposition of the optical fingerprint module <NUM> can be reduced, and only a width D needs to be reserved for covering the non-display area of the display screen <NUM>. In <FIG>, an area of a width d needs to be reserved for disposition of the optical fingerprint module <NUM>. It can be seen that D is far less than d, and a saved area can be used for disposition of the display screen <NUM>, that is, the area of the display screen <NUM> is increased. When the front panel size of the mobile terminal is not changed, increasing the area of the display screen <NUM> improves the screen-to-body ratio of the mobile terminal.

During specific configuration, to secure the optical fingerprint module <NUM> and the display screen <NUM>, in this embodiment of this application, the optical fingerprint module <NUM> is fixedly connected to the display screen <NUM>. In addition, the connection may be implemented in different manners. The following provides details with reference to the specific accompanying drawings and embodiments.

Still referring to <FIG>, structures of the display screen <NUM> and the optical fingerprint module <NUM> in this embodiment are the same as the structures in the foregoing embodiment, and this embodiment is only to show a specific connection manner between the optical fingerprint module <NUM> and the display screen <NUM>.

In this embodiment, the optical fingerprint module <NUM> is bonded to the display screen <NUM>. Specifically, the optical fingerprint module <NUM> is bonded to the display screen <NUM> by using a bezel adhesive <NUM>. As shown in <FIG>, the bezel adhesive <NUM> is applied around the fingerprint detection area <NUM> of the sensor <NUM>, and is bonded to the packaging layer <NUM>. During connection, the display screen <NUM> and the packaging layer <NUM> are bonded together by using the bezel adhesive <NUM>, to secure the optical fingerprint module <NUM> and the display screen <NUM>.

In this case, as shown in <FIG>, the through hole <NUM> of the display screen protective layer <NUM> is relatively large, and can accommodate the packaging layer <NUM> of the optical fingerprint module <NUM>, thereby ensuring that the packaging layer <NUM> can be securely connected to the display screen <NUM>.

In this connection manner, there is an air layer between the sensor <NUM> and the display screen <NUM>, so that an air bubble that interferes with light transmission can be avoided during bonding.

Optionally, the optical fingerprint module <NUM> may be connected to the display screen by using a middle frame <NUM>. As shown in <FIG>, the middle frame <NUM> has a second through hole <NUM> that is larger than the fingerprint detection area <NUM> and smaller than the through hole <NUM> of the display screen protective layer <NUM>. A bezel adhesive <NUM> may be, for example, applied around the second through hole <NUM>, to ensure bonding strength and dustproof performance. The middle frame <NUM> is connected to the display screen <NUM> by using the bezel adhesive <NUM>, and a thickness of the bezel adhesive <NUM> only needs to be greater than or equal to that of the display screen protective layer <NUM>. A gap between the middle frame <NUM> and the display screen protective layer <NUM> is not limited.

The optical fingerprint module <NUM> is bonded to a surface of the middle frame <NUM> away from the display screen <NUM> by using the bezel adhesive <NUM>. As shown in <FIG>, the bezel adhesive <NUM> is applied around the fingerprint detection area <NUM> of the sensor <NUM>, and is bonded to the packaging layer <NUM>. During connection, the middle frame <NUM> and the packaging layer <NUM> are bonded together by using the bezel adhesive <NUM>, to secure the optical fingerprint module <NUM> and the middle frame <NUM>.

A connection relationship between the middle frame <NUM> and the display screen <NUM> in <FIG> is only an example, and the relationship between the middle frame <NUM> and the display screen <NUM> may be adjusted based on an actual requirement. For example, a step-like structure (not shown in the figure) may be disposed at an end, connected to the display screen <NUM>, of the middle frame <NUM>, and protective glass (not shown in the figure) in the display screen <NUM> is connected to the step-like structure. The connection relationship between the middle frame <NUM> and the display screen <NUM>, a specific structure of the middle frame <NUM>, and a specific structure of the display screen are not described herein.

In a variant of this embodiment, as shown in <FIG>, the optical fingerprint module <NUM> is further bonded to the display screen <NUM> by using an optical clear adhesive <NUM>, and the optical clear adhesive <NUM> is disposed in the fingerprint detection area. In other words, the optical fingerprint module <NUM> and the display screen <NUM> are connected by using both the bezel adhesive <NUM> and the optical clear adhesive <NUM>. In this case, the optical clear adhesive <NUM> covers the fingerprint detection area <NUM>, and the bezel adhesive <NUM> is applied around the optical clear adhesive <NUM>. To ensure operating stability of the optical fingerprint module <NUM>, light transmittance of the optical clear adhesive <NUM> is not less than <NUM>%, for example, <NUM>%, <NUM>%, or <NUM>%, so that light reflected by a fingerprint can be transmitted to the fingerprint detection area <NUM>. The optical clear adhesive may be different adhesives, such as a polyurethane adhesive, a silicone gel adhesive, and a light-curing adhesive.

As shown in <FIG>, structures of the display screen <NUM> and the optical fingerprint module <NUM> in this embodiment are the same as the structures in the foregoing embodiments, and this embodiment is only to show a specific connection manner between the optical fingerprint module <NUM> and the display screen <NUM>.

In this embodiment, the optical fingerprint module <NUM> is bonded to the display screen protective layer <NUM>. Specifically, the optical fingerprint module <NUM> is bonded to the display screen protective layer <NUM> by using the bezel adhesive <NUM>. As shown in <FIG>, the bezel adhesive <NUM> is applied around the fingerprint detection area <NUM> of the sensor <NUM>, and is bonded to the packaging layer <NUM>. During connection, the display screen protective layer <NUM> and the packaging layer <NUM> are bonded together by using the bezel adhesive <NUM>, to secure the optical fingerprint module <NUM> and the display screen <NUM>.

In this case, as shown in <FIG>, the through hole <NUM> of the display screen protective layer <NUM> is relatively small, and does not allow the packaging layer <NUM> to pass through, so that the display screen protective layer <NUM> can be bonded to the packaging layer <NUM>.

In this manner, the display screen <NUM> is not in direct contact with the optical fingerprint module <NUM>, thereby avoiding damage to the display screen <NUM> during an assembly or repairing process, and improving safety of the display screen <NUM>.

Optionally, in a structure of the display module shown in <FIG>, the optical fingerprint module <NUM> may be further connected to the display screen protective layer <NUM> by using the middle frame <NUM>. As shown in <FIG>, the middle frame <NUM> has a second through hole <NUM> that is larger than the fingerprint detection area <NUM> and smaller than or equal to the through hole <NUM> of the display screen protective layer <NUM>. The middle frame <NUM> is bonded to the display screen protective layer <NUM> by using the bezel adhesive <NUM>, and the optical fingerprint module <NUM> is bonded to a surface of the middle frame <NUM> away from the display screen protective layer <NUM> by using the bezel adhesive <NUM>.

As shown in <FIG>, in this embodiment, the optical fingerprint module <NUM> includes the sensor <NUM>, the packaging layer <NUM> for packaging the sensor <NUM>, and the flexible printed circuit board <NUM> connected to the sensor <NUM>, and further includes a U-shaped support plate <NUM>. A concave area of the support plate <NUM> is fixedly connected to the support plate <NUM>, a bending structure is disposed on each of two side walls of the support plate <NUM>, and the bending structure is bonded to the display screen protective layer <NUM>. The U-shaped support plate <NUM> may be understood as a variant of the stiffener <NUM> in the foregoing embodiment. To be specific, two sides of the stiffener <NUM> extend and are bent to form a support structure, and the bending structure is bonded to the display screen protective layer <NUM>. Specifically, the bending structure is bonded to the display screen protective layer <NUM> by using the bezel adhesive <NUM>.

During connection, the bending structure is coated with a layer of bezel adhesive <NUM>, and is bonded to the display screen protective layer <NUM> by using the bezel adhesive <NUM>.

It can be learned from the specific Embodiment <NUM>, Embodiment <NUM>, and Embodiment <NUM> that the optical fingerprint module <NUM> and the display screen <NUM> may be fixedly connected in different manners in this embodiment. It should be understood that Embodiment <NUM>, Embodiment <NUM>, and Embodiment <NUM> are only examples of specific connection manners, in this embodiment, the display screen <NUM> and the optical module may be fixedly connected by using another known connection manner.

It should be noted that if the flexible printed circuit board (Flexible Printed Circuit, FPC) connected to the display screen <NUM> is bent and disposed under the through hole, it is self-evident that a second through hole with a shape and a size corresponding to the through hole <NUM> needs to be disposed on the FPC, to provide a necessary light path. Further, the middle frame <NUM> may be bonded to the FPC by using the bezel adhesive <NUM>, or the optical fingerprint module <NUM> may be bonded to the FPC by using the bezel adhesive <NUM>. More descriptions are not provided herein.

In addition, it should be noted that widths of the bezel adhesives <NUM> and <NUM> on a plane vertical to the light-out surface of the display screen <NUM> are not limited to the widths shown in <FIG>, provided that the fingerprint detection area <NUM> of the optical fingerprint sensor <NUM> is not covered.

As shown in <FIG>, this embodiment further provides a mobile terminal, where the mobile terminal includes a housing and the display module disposed in the housing according to any one of the foregoing embodiments.

In the foregoing technical solutions, the optical fingerprint module <NUM> is used to detect a fingerprint, and the optical fingerprint module <NUM> is disposed under the display screen <NUM>, so that a fingerprint can be collected when a finger presses the screen. Different from a mobile terminal in the prior art, because the optical fingerprint module <NUM> is disposed under the display screen <NUM>, no space of the front panel of the mobile terminal needs to be occupied, and more space can be used for disposition of the display screen <NUM>, thereby increasing an area of the display screen <NUM>, increasing a display size of the mobile terminal, and improving the screen-to-body ratio.

Claim 1:
A display module, comprising a display screen (<NUM>), an optical fingerprint module (<NUM>) and a display screen protective layer (<NUM>), characterized in that
the optical fingerprint module (<NUM>) is located on a surface of the display screen (<NUM>) away from a light-out surface;
the optical fingerprint module (<NUM>) comprises a sensor (<NUM>), a packaging layer (<NUM>) for packaging the sensor (<NUM>) and a flexible printed circuit board (<NUM>) connected to the sensor (<NUM>); the sensor (<NUM>) comprises a fingerprint detection area (<NUM>), the packaging layer (<NUM>) packages the sensor (<NUM>) with the fingerprint detection area (<NUM>) on the sensor (<NUM>) exposed; the flexible printed circuit board (<NUM>) is configured to transmit a signal detected by the sensor (<NUM>);
the display screen protective layer (<NUM>) located on the surface of the display screen (<NUM>) away from the light-out surface; a through hole (<NUM>) is disposed at the display screen protective layer (<NUM>); the display screen protective layer (<NUM>) is fixedly connected to the display screen (<NUM>);
a vertical projection of the fingerprint detection area (<NUM>) of the optical fingerprint module (<NUM>) on the light-out surface of the display screen (<NUM>) is located inside a display area (<NUM>) of the display screen (<NUM>), and light is able to be transmitted through the display screen (<NUM>) and the through hole (<NUM>) to the fingerprint detection area (<NUM>);
the optical fingerprint module (<NUM>) is bonded to a middle frame (<NUM>) by using a bezel adhesive (<NUM>), wherein a second through hole (<NUM>) is disposed at the middle frame (<NUM>);
the bezel adhesive (<NUM>) is applied around the fingerprint detection area (<NUM>) of the sensor (<NUM>) and is bonded to the packaging layer (<NUM>); there is a gap between the fingerprint detection area (<NUM>) and the display screen (<NUM>).