7-inch TFT LCDs by Winstar with two brightness options

In some devices, the screen needs to fit into a front panel with limited height while remaining easy to use and read. Examples include audio processors, rack-mounted networking equipment and compact machine controllers. The elongated shape of bar-type displays allows the interface to fit this space. Operating parameters, messages and buttons can be arranged side by side in a single, clearly organised view.

For these applications, Winstar offers two 7-inch TFT LCDs with IPS technology and capacitive touch panels: WF70C9TYAB4MNC1B and WF70C9SYAB4MNC1B. Their backlight specifications differ, allowing designers to select the version that suits the indoor lighting conditions. The first provides a typical brightness of 400 cd/m² with lower backlight power consumption, while the second offers 800 cd/m² for improved readability in brighter surroundings.

An elongated format

WF70C9SYAB4MNC1B and WF70C9TYAB4MNC1B are 7-inch displays with an aspect ratio of approximately 1:5, giving them their distinctive, elongated bar-type format. Both modules have overall dimensions of 38.2 × 186.62 × 5.76 mm, allowing either brightness option to be incorporated into the same enclosure design.

Depending on the device design and how information is presented, the elongated display can be used in either horizontal or vertical orientation.

Horizontal orientation

In horizontal orientation, the elongated format makes use of spaces where height is limited but more width is available. The screen can occupy a narrow strip of the front panel, leaving the remaining area available for other components.

This arrangement allows information to be presented in a single, continuous view. Operating parameters, the status of individual parts of the device and function buttons can be placed side by side, making values easier to compare and keeping the interface clearly organised.

Vertical orientation

In vertical orientation, the elongated format makes use of spaces where width is limited. The screen can be integrated into a narrow front panel or a section of the enclosure without increasing the overall width of the device.

This arrangement is particularly useful for information presented vertically, such as lists of settings, messages or successive stages of a process. Content can follow a natural top-to-bottom sequence, making information easier to browse and the interface easier to navigate.

Resolution and contrast – interface readability

Both models offer a resolution of 280 × 1424 px within an active area measuring 33.60 × 170.88 mm. A pixel pitch of 0.12 mm in both axes results in a pixel density of approximately 212 ppi, allowing small elements such as text, symbols and scale markings to be rendered in detail. This makes it easier to present function labels, numerical values and units of measurement within the limited screen area.

A contrast ratio of 1000:1 provides clear differentiation between light and dark elements. With a suitable interface colour scheme, labels remain distinguishable from the background, while important messages and indicators can stand out.

IPS technology

Both models use IPS (In-Plane Switching) technology, which reduces shifts in colour and contrast when the screen is viewed at an angle. Typical viewing angles are 80° in each direction (80°/80°/80°/80°), allowing information to be read from the left, right, above and below. This matters when the screen is positioned above or below eye level, or when the user changes position while operating the device.

Brightness to suit the surroundings

The models differ in their backlight specifications: brightness and current consumption. This allows the display to be selected for different indoor operating conditions while retaining the same dimensions, resolution, touch functionality and interfaces.

With a brightness of 400 cd/m², WF70C9TYAB4MNC1B is intended for indoor applications where moderate ambient lighting does not require a brighter backlight. WF70C9SYAB4MNC1B offers 800 cd/m², supporting image readability in more brightly lit interiors. This is relevant, for example, to equipment installed near windows or glass façades, where more daylight may reach the screen.

The difference in brightness also affects backlight current consumption. At a typical voltage of 6 V, this is 120 mA for the 400 cd/m² version and 240 mA for the 800 cd/m² version, corresponding to approximately 0.72 W and 1.44 W respectively. Under these conditions, the lower-brightness version therefore uses half as much backlight power. These figures apply only to the LED backlight, not to the complete modules.

Image data transmission – the MIPI interface

Both displays use a MIPI DSI interface with four data lanes (4-lane) for high-speed image data transmission between the control electronics and the TFT LCD module. Data is transmitted over four differential signal pairs, accompanied by a separate differential clock pair. This provides the bandwidth required for the 280 × 1424-pixel image.

The module connects to the device electronics through a 30-pin FPC, which carries the MIPI signals as well as power, control and backlight connections. Using the same interface and pinout for both brightness options makes it easier to develop a common control electronics design. However, the different LED backlight power requirements must be taken into account when switching between versions.

Integrating these modules requires a processor or controller that supports MIPI DSI, correctly configured transmission parameters and appropriate routing of high-speed differential signals on the PCB. Trace impedance, trace lengths and the control of interference are particularly important for reliable image data transmission.

Capacitive touch panel

Both models feature a capacitive touch panel for direct interaction with the device interface. The GFF (Glass–Film–Film) structure consists of glass and two film layers with touch-sensing electrodes. The panel is managed by a GT911 controller, which communicates with the device electronics over an I²C interface. A separate 6-pin FPC provides the connection. As the touch panel leaves only part of the TFT active area visible, buttons and labels must be positioned so that they remain fully visible to the user.

Optical bonding – improved image readability

Image quality is also affected by the way the display and touch panel are bonded together. Both models use optical bonding with optically clear adhesive (OCA), which fills the space between these components and eliminates the air gap. This reduces internal reflections that could otherwise make information harder to read.

We discuss the benefits of this method and how it differs from air bonding in our article Optical bonding vs. air bonding.

The table below compares the key technical specifications of both models:

Pa­ra­me­ter	WF70C9SYAB4MNC1B	WF70C9TYAB4MNC1B
Di­ag­o­nal size	7.0″	7.0″
Res­o­lu­tion	280 × 1424 px	280 × 1424 px
As­pect ratio	1:5	1:5
Bright­ness	800 cd/m²	400 cd/m²
Con­trast ratio	1000:1	1000:1
View­ing an­gles	80°/80°/80°/80° (IPS)	80°/80°/80°/80° (IPS)
Over­all di­men­sions	38.2 × 186.62 × 5.76 mm	38.2 × 186.62 × 5.76 mm
Ac­tive area	33.60 × 170.88 mm	33.60 × 170.88 mm
Dis­play in­ter­face	MIPI DSI	MIPI DSI
Touch panel	Ca­pac­i­tive	Ca­pac­i­tive
Touch con­troller	GT911	GT911
Touch panel in­ter­face	I²C	I²C
Op­er­at­ing tem­per­a­ture	−20°C to +70°C	−20°C to +70°C
LED back­light life­time	50,000 h	50,000 h

Application examples

WF70C9TYAB4MNC1B – applications in moderate ambient lighting

WF70C9TYAB4MNC1B can be used in equipment operating indoors under moderate ambient lighting. Examples include:

• professional audio equipment – rack-mounted audio processors, amplifiers and audio matrix systems, with screens showing signal levels, settings and channel status;
• laboratory and measurement equipment – bench power supplies, multichannel data loggers and temperature controllers with limited front-panel height;
• building automation – ventilation, air conditioning and lighting control panels that combine parameter monitoring with settings adjustment;
• household appliances – coffee machines, extractor hoods and other devices with an elongated control panel.

WF70C9SYAB4MNC1B – applications in brighter interiors

WF70C9SYAB4MNC1B is suited to indoor applications exposed to strong task lighting or higher levels of daylight. In these conditions, its higher brightness can improve readability in applications such as:

• industrial automation – control panels for conveyors, dispensers and small packaging machines installed in brightly lit areas of production facilities;
• production and quality control – electric screwdriver controllers, leak testers and assembly workstation panels displaying settings, results and operation status near task lights;
• retail and services – water dispensers, automatic dispensers and coffee machines with narrow drink-selection panels, installed near shopfront windows;
• building automation and access control – indoor entry panels and building system controllers in glazed lobbies and reception areas.

These examples illustrate how lighting conditions can guide selection. Either the 400 or 800 cd/m² version can be used within the same equipment category, depending on the installation location and power consumption requirements.

Not sure which version is right for your application? Contact us – we can assist you in selecting a display that suits your operating conditions, power supply requirements and device design.