The display interface design of a portable breathalyzer needs to balance functionality, ease of use, and adaptability to user scenarios. Its core objective is to ensure users can quickly and accurately read measurement values under different lighting conditions and usage states through a reasonable layout, clear visual feedback, and user-friendly interaction logic. The design process requires comprehensive consideration of multiple dimensions, including display technology, information hierarchy, color contrast, font selection, and dynamic feedback, to achieve efficient and accurate information transmission.
The choice of display technology directly affects the clarity and readability of the interface. Portable breathalyzers typically use LCD or OLED screens. OLED, due to its self-emissive nature, has higher contrast in low-light environments and can clearly display values without backlighting, making it suitable for nighttime or low-light scenarios. LCD screens, on the other hand, require backlight adjustment to adapt to different environments, but are relatively cheaper. Regardless of the technology chosen, the screen resolution must be high enough to ensure sharp, jagged edges on the values, avoiding blurry numbers due to insufficient pixels. Furthermore, scratch-resistant and fingerprint-resistant coatings on the screen can improve the display effect after long-term use, reducing the impact of surface stains on readability.
The division of information hierarchy is key to improving reading efficiency. The display interface of an alcohol tester needs to simultaneously present the test result, unit, status indicators, and potential warnings. If the information is disorganized, users will spend time searching for key data. Therefore, the core value (such as blood alcohol concentration, BAC) should be placed in the center of the screen, highlighted with large font and high-contrast colors. Units (such as mg/L or ‰) should be placed to the right or below the value in smaller font to avoid competing for attention with the main value. Status indicators (such as "Testing in progress" or "Waiting for breathalyzer test") can be placed at the top or bottom of the screen as icons or text, while warnings (such as "Exceeded the limit" or "Device malfunction") should use striking red or flashing effects to attract the user's attention, ensuring that emergencies can be quickly identified.
The use of color contrast can significantly enhance the interface's readability. Core values should use colors that strongly contrast with the background, such as a dark background with white or yellow values, or a light background with black values. Avoid using low-contrast combinations (such as gray text on a white background). Warnings should convey a sense of urgency using high-saturation colors such as red and orange, and can be further reinforced with flashing or dynamic effects. In addition, the overall color scheme of the interface should be kept simple to avoid visual clutter caused by too many colors. Generally, no more than three main color schemes are sufficient.
Font selection directly affects the readability of numerical values. The numerical portion should use sans-serif fonts (such as Arial or Helvetica), whose strokes are of uniform thickness and remain clear even at small sizes. Avoid using serif fonts (such as Times New Roman) or handwriting, as stroke details are easily blurred on small screens. Font thickness should also be moderate; overly thin fonts may be difficult to read under strong light, while overly thick fonts may take up too much space and affect the display of other information. Furthermore, the spacing between numbers should be reasonable to avoid overly dense spacing leading to curly strokes or misreading.
Dynamic feedback design can enhance the user experience. For example, during the breath-blowing test, the interface can display the blowing force and duration through a progress bar or animation effects to guide the user to complete the correct operation. After the test is completed, the numerical value can be displayed with a short animation (such as fade-in/fade-out) to avoid sudden jumps that could cause the user to lose focus. If the device supports voice prompts, the interface can display text and voice content simultaneously to meet the needs and preferences of different users. Environmentally adaptable design is key to ensuring a clear interface. Portable breathalyzers are often used outdoors or in vehicles under complex lighting conditions. Therefore, the screen needs automatic brightness adjustment, dynamically adjusting the backlight or OLED brightness based on ambient light intensity to ensure values are always clearly visible. Furthermore, the screen's viewing angle needs to be wide enough to prevent color shifts or blurry values when viewed from the side.
User testing and iterative optimization are essential parts of the design process. During the prototyping phase, target users (such as traffic police, drivers, or ordinary consumers) should be invited to conduct real-world testing to observe reading efficiency and user experience in different scenarios. Feedback should be collected to adjust the interface layout, color scheme, and font size. For example, if users report severe glare under strong light, a screen matte finish or adjusted viewing angle could be considered; if warning messages are ignored, color contrast could be enhanced or sound prompts added. Through multiple iterations, a high-definition display interface that meets user needs can be ultimately achieved.
