Electronic components for mobile phones

Touch Panel: Electronic Product Enabling Intuitive User Operation
Touch Panels Featuring in Wide-Ranging Applications

Touch Panel

Touch Panel

Touch panels enable intuitive user operation by offering direct contact with a screen while looking at a display. In addition to mobile phones, they are being used for wide-ranging applications in our everyday lives, such as compact game consoles, banking facility ATMs, ticket vending machines at railway stations, in-car navigation systems and combined fax/copier machines. The operating parts of these kinds of devices comprises a touch panel for position detection and image display components that show graphics and messages. Alps Electric develops and manufactures such parts.
With a touch panel, a user is able to operate a device simply by touching specific points on the screen. The panel sends sends signals indicating the position of the user’s touch to the device’s main electronic components. The operating principle involves electrodes embedded in a matrix. These electrodes are what detects the position of the user’s touch—or, more specifically, the points the user touches subsequent to the first contact—and they convey this information to the device. This, in turn, allows the device to carry out pre-programmed operations in accordance with the point on the screen that the user has chosen.
Touch panels utilize a variety of methods to detect touch position. Lightly touching the panel causes two membranes to come into contact, a resistive-type mesh that determines the location of the touch and a surface electrostatic capacitance-type mesh that reads changes in the weak magnetic field emanating from the electrode. There are also optical, electromagnetic induction and surface acoustic wave meshes. Of these, Alps Electric develops and produces resistive-type touch panels.

Utilizing Alps Electric’s Specialist Process Engineering

Newton rings

Newton rings

Alps Electric touch panels feature high impact resistance and are lightweight yet have high transmittance. Normally, touch panels are made up of either multiple layers of combinations of film and plastic or film and glass, but Alps Electric touch panels comprise only one layer each of film and plastic. Nevertheless, they contribute to products that are difficult to break and offer high transmittance. Transmittance refers to the percentage of light (incident light) that passes through an item. Alps Electric touch panels have a transmittance of more than 80%, which means that more than 80% of the light transmitted passes through. If transmittance is high, image displays like liquid crystal displays stay bright, enabling the faithful reproduction of clear images.
In addition, Alps Electric boasts superior plastic molding processes that enable panels to be processed for a wide range of configurations. This also facilitates compatibility with set products with innovative designs.
The main point is the ease with which users can view images. Standard touch panels are made of multiple layers of film and glass or plastic plates. This resluts in the creation of tiny space between the film and the plate, and the surface of each layer reflects light. This reflection causes interference and Newton rings to appear on the screen, making it difficult to properly see the image on the screen. Even here we utilize microfabrication technology—one of our superior process engineering technologies—to prevent Newton rings by incorporating tiny irregularities (prism processing) into the surface of the plastic plate to cause the reflected light to diffuse.

Electric Components Used in Mobile Phones
Contactsheet™ with Light Guide Developed in Response to Illumination Design Needs

Contactsheet

Contactsheet™

In addition to color and shape, light is used to a great extent in the design of mobile phones. Along with this, there is a need for this illumination—which uses LEDs as the light source—to be ever more beautiful and effective. In order to meet such demand, Alps Electric introduced Contactsheet™ with Light Guide.
Contactsheet™ is an operational device that uses metal contacts mounted on an adhesive sheet that is placed under the key pad of a mobile phone. By attaching a “light guide” to the Contactsheet™, Alps Electric is able to offer value-added lighting and illumination design.
A light guide has two major roles: ensuring the efficient use of the light source and enhancing design quality. Owing to these features, light guides offer brighter and more consistent lighting even when used in conjunction with fewer LEDs, contributing to the cost efficiently of set products and improving the overall design.
Alps Electric’s light guide is a transparent film 0.1mm to 0.15mm thick made from polycarbonate or urethane material. Light is projected into the light guide from the side and is repeatedly deflected within the light guide on its journey to the other side. Ditches cast into the surface of the light guide allow the light traveling inside the film to become visible, creating an effect in which it looks as if the entire light guide is glowing.

With each type of mobile handset, the arrangement of keypads and LED light source is different.
Therefore, except for the basic structure, the Contactsheet™ and light guide can be customized for each type of handset.
Leveraging its light simulation technology, Alps Electric’s light guide realizes lighting to meet any need
by enabling surface ditches that are made according to precise calculations of depth and pitch in relation to the location of the light source.

Many people have noticed that using the keypads of new model mobile phones feels different. Alps Electric excels at the creation of “sensation and feeling.” The difference in this case is due to the metal contacts of the Contactsheet™. By shaping the metal contact, essentially a metal plate spring, in different ways, a variety of sensations are realized.
Alps Electric will continue to respond to needs for diverse operational sensations and designs for various types of mobile handsets, while developing value-added features like light guides.

Geomagnetic Sensor to Indicate Direction

Geomagnetic Sensor

Geomagnetic Sensor

Equipped with various functions, including cameras, audio systems, digital terrestrial broadcast reception and Internet connections, today’s mobile phones have become information terminals.
A global positioning system (GPS) is one of the functions installed in many mobile phones and works like a car navigation system to guide users to their destinations. In order to perform such a navigation function, a mobile phone must know the user’s current location and the direction the user is travelling. For this purpose, geomagnetism, specifically the earth’s magnetic field, is utilized. Alps Electric has experimented with its geomagnetic sensor to ensure that it is suitable for use as a mobile phone component.
A common tool using geomagnetism to indicate direction is a compass. Many people may recall how to use a compass: place it on the palm of your hand, keeping it parallel with the ground. This is because a compass can accurately indicate geomagnetic force only when it is in a horizontal position. A browsing mobile phone display, however, is generally held in an almost vertical position. In such a position, a tool that functions like an ordinary compass cannot detect position accurately, therefore, a device that can triangulate is required.
Alps Electric’s geomagnetic sensor enables triangulation despite its compact size of 2.5mm square by 0.7mm high. With an excellent magnetic detection range thanks to the incorporation of Alps Electric’s proprietary high-precision magnetic element, this geomagnetic sensor can theoretically detect geomagnetism from the Scandinavian peninsula to southernmost tip of South America. Furthermore, a shielding structure has been build into the geomagnetic sensor to reduce interference from other magnetic fields. Such fields are emitted by such devices commonly found in mobile phones as speakers. In response, Alps Electric has developed a device that ensures certain and accurate geomagnetic detection in such an environment.

The Components Packed into Mobile Phones

There are many electronics components mounted inside mobile phones other than those showcased above. We’d like to present some of the other components that Alps Electric produces for mobile phones.

Magnetic Sensors

Magnetic Sensors

These components detect a magnet’s magnetic field. They are used to detect the opening and closing of mobile phone covers and the rotation of display components.
Alps Electric utilizes its accumulated technologies in the development and production of magnetic heads for audio and HDD use. In addition, the development of new sensors that utilize capacitance, piezoelectric elements, etc., is under way.

 

TACT Switch

TACT Switch™

The main feature of this product is the clicking sensation it conveys to the user when he or she presses with a finger and returns to its original position.
The compact TACT Switch™ utilized in mobile phones, an Alps Electric representative product, measures only 3mm and is less than 1mm thick.

 

Compact Detection Switches

Compact Detection Switches

Detect mechanism movement, for instance the opening and closing of mobile phone covers.

 

Switches

Switches

Used when switching over modes of operation, these switches work by the user sliding a switch up and down or when the shutter button on an autofocus camera is pressed halfway down.

 

GlideSensor

GlideSensor™

GlideSensor™ is an input device that uses the same capacitance as notebook PC touch pads. It enables screen operation and graphic/text input of the kind used on touch pads on mobile phones.

 

Memory Card Connectors

Memory Card Connectors

Mobile phones utilizing memory cards, primarily the microSD™ to save music and images, are gaining market predominance. Alps Electric is leveraging its mechanism design technologies to improve design reliability and to secure data exchanges between compact memory cards and mobile phones.

 

Contactsheet

Contactsheet™

Metal contacts used in Alps Electric’s TACT Switch™ are arranged on sheets. Contactsheet™ was developed to facilitate the arrangement of numerous switches, for example, for mobile phone numeric keypad components, in specified spaces. Contactsheet™ is contributing to the making of thinner, more compact mobile phones.

 

Communication and Broadcast Modules

Communication and Broadcast Modules

Alps Electric produces diverse types of communication modules for small devices. Representative products include Bluetooth® modules for short-range wireless communication and modules for one-seg broadcast reception.

 

Magnetic Sheets Liqualloy

Magnetic Sheets Liqualloy™

The development of Liqualloy™ Magnetic Sheets came as the result of many years’ of studying the utilization of magnetic materials that leverage Alps Electric’s experience in the manufacture of magnetic heads. There are two of product in the lineup that are based on an electronic noise control function and boosts the electromagnetic waves of RFID system communications.