Sharp LQ4RB21 | Reliable 4-inch WQVGA Display for Industrial HMI
The Sharp LQ4RB21 is a 4.0-inch TFT-LCD display module engineered for reliability and long-term performance in industrial applications. Eschewing fleeting consumer trends, this display focuses on delivering a robust, cost-effective, and easy-to-integrate solution for human-machine interfaces (HMIs), control panels, and specialized instrumentation where clarity and operational dependability are paramount.
Product Highlights:
- Proven Industrial Pedigree: Built by Sharp, leveraging mature Amorphous Silicon (a-Si TFT) technology for consistent performance and supply chain stability.
- Optimal Resolution for Control Interfaces: The 480x272 WQVGA resolution provides a crisp, clear canvas for displaying critical operational data, menus, and status indicators without overwhelming the system's processing resources.
- Simplified Integration: Features a standard 8-bit Parallel RGB interface, enabling direct connection to a wide range of microcontrollers (MCUs) and system-on-chips (SoCs), reducing design complexity and BOM cost.
- Compact and Versatile Form Factor: The 4.0-inch diagonal is ideal for space-constrained applications, including portable test equipment and compact machine control units.
Key Parameters at a Glance
Engineers require precise data for component evaluation. The table below outlines the core specifications of the LQ4RB21. For comprehensive electro-optical characteristics and mechanical drawings, download the full LQ4RB21 datasheet.
| Parameter | Specification |
|---|---|
| Manufacturer | Sharp |
| Model | LQ4RB21 |
| Diagonal Size | 4.0 inches |
| Resolution | 480(RGB)×272 (WQVGA) |
| Technology | a-Si TFT Active Matrix |
| Luminance (Brightness) | 350 cd/m² (Typ.) |
| Contrast Ratio | 200:1 (Min.) |
| Interface | Parallel RGB (1 ch, 8-bit), 40 pins FPC |
| Operating Temperature | -10°C to +60°C |
| Storage Temperature | -25°C to +70°C |
Application Scenarios & Value Proposition
The true value of the Sharp LQ4RB21 lies in its application-specific strengths. It is not designed to compete with high-definition consumer displays, but to excel in environments where durability and function are the primary design drivers.
- Industrial Control Panels: Perfect for HMIs on machinery where operators need to monitor processes, input setpoints, or view alarms. The resolution is ample for graphical elements and text without requiring a powerful graphics processor. For a deeper understanding of how modern HMIs are evolving, see the guide on HMI and automation trends.
- Portable Test and Measurement Devices: The compact size, modest power consumption, and straightforward interface make it an excellent choice for handheld diagnostic tools, environmental meters, and network testers.
- Legacy System Retrofits and Upgrades: The parallel RGB interface is a common standard in older industrial equipment. The LQ4RB21 serves as a reliable, form-fit-function replacement for end-of-life displays, extending the service life of valuable capital equipment.
- Appliance and Building Automation: Ideal for smart thermostats, security system keypads, and other embedded systems that require a clear, functional display with a long operational life.
Engineer's FAQ for the LQ4RB21
We anticipate the questions our engineering clients ask most frequently when evaluating a display like the LQ4RB21.
1. Is this display sunlight readable?
With a typical brightness of 350 nits, the LQ4RB21 is designed for indoor and shaded environments. It delivers excellent clarity under typical factory floor or laboratory lighting. For applications in direct sunlight, a specialized sunlight-readable HMI with brightness levels exceeding 1000 nits and advanced optical bonding would be required.
2. Can a touchscreen be integrated with this module?
The LQ4RB21 is a non-touch display module. However, its mechanical frame is designed to facilitate the addition of a separate touch panel overlay. This gives designers the flexibility to integrate either a pressure-sensitive Resistive Touch Panel (RTP), ideal for gloved operation, or a multi-touch Projected Capacitive (PCAP) panel, depending on the application's specific needs.
3. What are the advantages of the Parallel RGB interface?
For a WQVGA resolution display, a parallel interface offers significant design advantages. It is a "raw" data interface that minimizes latency and eliminates the need for complex, costly serializer/deserializer (SerDes) chipsets often required for LVDS or MIPI interfaces. This results in a simpler PCB layout, a lower bill of materials (BOM), and faster design-to-production cycles.
For detailed selection guidance or to discuss how the Sharp LQ4RB21 can fit into your next project, please contact our technical team for expert consultation and sourcing support.
