Mobile Terminal Front Case Layout for Overlapped Fingerprint Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing mobile terminals face challenges in maximizing screen output area while incorporating a fingerprint sensing region, as conventional designs often require separate spaces for these functions, reducing the available display area.

Innovation Solution

A mobile terminal design that integrates a detachable finger scan sensor part on the rear surface of the front case, allowing the fingerprint sensing region to overlap with the screen displaying region, thereby maximizing the screen output area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the fingerprint sensing region is provided separate from the screen output region, then fingerprint recognition function is ensured, but the screen output area is reduced

Engineering Contradiction:
Improvescreen output areaVSAvoidfingerprint sensing function
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent merges the fingerprint sensing region with the screen output region by positioning the finger scan sensor part to overlap with the display area. The sensor is fixed to the rear surface of the front case, allowing simultaneous operation of display and fingerprint recognition functions within the same spatial footprint, thereby maximizing screen output area while maintaining biometric authentication capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a planar separation approach to a three-dimensional overlapping arrangement. By fixing the finger scan sensor part to the rear surface of the front case and allowing it to overlap the screen displaying region, the solution utilizes vertical layering and spatial depth to resolve the conflict between display area and sensing function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the finger scan sensor part is adhered directly to the display, then compact structure is achieved, but detection precision deteriorates due to interference with display performance

Engineering Contradiction:
Improvestructure compactnessVSAvoidfingerprint detection precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces the front case rear surface as an intermediary mounting position between the finger scan sensor part and the display. This intermediate location allows the sensor to be positioned close to the display for compactness while maintaining sufficient distance and optical path clearance to prevent interference with display performance and ensure accurate fingerprint detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If the fingerprint sensing region is disposed at the rear or side surface, then screen output area is maximized, but device complexity increases

Engineering Contradiction:
Improvescreen output areaVSAvoidstructural complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The front case rear surface serves multiple functions: it provides structural support for the mobile terminal, acts as a mounting surface for the finger scan sensor part, and maintains the overall compactness of the device. This multi-functional use of the front case reduces the need for additional dedicated structures, thereby minimizing device complexity while achieving maximized screen output area.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4027622B1Mobile terminal
Publication Date: 2026.03.11 LG ELECTRONICS INC
  • EP4027622B1 patent drawingFigure 1
  • EP4027622B1 patent drawingFigure 2A~2B
  • EP4027622B1 patent drawingFigure 3

AI summary

Provided is a mobile terminal including a front case, a display disposed at a front surface of the front case, a rear case disposed to oppose a rear surface of the front case, and a finger scan sensor part coupled to the rear surface of the front case. The finger scan sensor part may be configured to sense at least a portion of light incident after passing through the display and the front case among light reflected by an external object. Other embodiments are implementable.