How To Select The Right Touchscreen Technology?

How-To-Select-The-Right-Touchscreen-Technology

Outlines: 

  1. What Is Touchscreen Technology?
  2. Multi-Touch Gestures
  3. Important things to consider when choosing a touchscreen technology
  4. What is the planned use of the device?
  5. Which touch features are required?
  6. How will the touchscreen be activated?
  7. What is the required environment to use touchscreen?
  8. What is the price point?
  9.  How many actuations does the touchscreen need to manage?
  10.  Final Words 

Touchscreens grow in popularity as a part of user interface systems and become a critical design decision. Each type of touchscreen, resistive or projected capacitive, offers many advantages. 

Do you want to know how to select the one that provides the optimal user experience from the wide variety of touchscreen options?

1. What Is Touchscreen Technology?

Traditional input devices for computer systems contain keyboards and mice. Touchscreen technology has become widely used to interact with computer systems and mobile devices.

A touchscreen is an electronic visual display that a user controls by touching the screen with fingers. A touchscreen allows more direct interaction with what is displayed than a mouse device. Touchscreens have become very common on smartphones, tablet computers, and other mobile devices. Additionally, standard laptops and desktop computers use touchscreen displays to use both touches and more traditional ways of input.

The first major successful technology was the resistive touchscreen, which uses a panel including two thin, electrically charged layers separated by a narrow space. These two layers touch by pressing the panel, and the location of the connection is recorded as the input. Resistive touchscreens are somewhat cheap and resistant to liquids, but they have relatively poor contrast, and you need to press them down with some pressure. Resistive touchscreens did not become widely used for computer systems but developed as part of other electronic systems. For instance, control panels in factories and the display screens used in restaurants to enter orders are resistive touchscreens.

The second major technology used in touchscreens is the capacitive touchscreen, which uses a layer of insulating material, such as glass, coated with a transparent conductor and touching the screen with your finger changes the screen’s electrostatic field. Several approaches can be used to record the location of the touch. Using a fine grid of capacitors is one of the most common ways to record the electrostatic field’s change. 

What-Is-Touchscreen-Technology

2. Multi-Touch Gestures

Touchscreen technology works similar to a computer mouse at a basic level. Instead of moving your pointer with a mouse, press the location with your finger. Multi-touch technology makes it possible to interact with the computer display in many ways. With touchscreen technology, tasks like scrolling up and down a web page, selecting text and drag-and-drop have become quite different. This figure shows several single and multi-touch gestures.

Touchscreen-Multi-Touch-Gestures

Things To Consider When Choosing A Touchscreen Technology

There are some important things you need to know while choosing a touchscreen, which are given below.

3. What Is The Intended Use Of The Device?

The first step is to precisely define what the device will be used for and which touchscreens are feasible. For instance,

Is the screen intended for an inexpensive toy where durability is not a huge concern?

Will your display be for a military application, subject to harsh conditions? 

Both situations require different durability, functionality, pricing, and input registration screen technologies. The next step is to figure out which functionalities are necessary once you have narrowed down the planned use for the display.

Things-To-Consider-When-Choosing-A-Touchscreen-Technology

4. Which Touch Features Are Required?

You should know about users’ preferences; for example, will users only need to select single inputs with one finger on your device? 

If Yes, a standard 4-wire resistive touchscreen is perhaps a perfect option for them. A 4-wire resistive touchscreen’s simple construction handles this without adding much cost. However, if users need to zoom, scroll, or activate features with multiple touchpoints, that will narrow the selection to screens with multi-touch functionality, such as a projected capacitive or a resistive multi-touch screen.

5. How Will The Touchscreen Be Activated?

Given how touchscreens register inputs, activating the screen is an important consideration. 

Will the user wear gloves or another object to touch the screen? If so, specific types of touchscreens are necessary to register those inputs. While the sensitivity of a projected capacitive touchscreen can be adjusted to note certain styluses and gloves, the object used must be able to disrupt the capacitive field. A resistive touchscreen is optimal for applications where other input devices can register inputs from nearly any object.

Things-To-Consider-When-Choosing-A-Touchscreen-Technology

6. What Is The Environment To Use Touchscreen?

Where the touchscreen will activate is another essential factor to consider.

Is it subject to drastic cleaning agents in a medical setting?

Will it be used in an industrial environment to repeat impacts? 

 PCAP technology is ideal if durability is a vital concern, given that damage to the cover glass does not change its ability to register inputs correctly. Resistive screens meet performance requirements for softer environments without adding additional cost.

7. What Is The Price Point?

Resistive touchscreens still tend to be cheaper, as PCAP touchscreens technology becomes more popular and its cost decreases. If you are looking for a touchscreen for a game, toy, or other cheap application, a simple 4-wire resistive touchscreen may add unnecessary cost to the device. However, a projected capacitive screen will be worth the additional cost in the case of a computer, smartphone, or other costly application that requires a high-end look.

8. How Many Actuations Does The Touchscreen Require To Handle?

Different touchscreen constructions are ranked for different numbers of actuations. A 4-wire or 8-wire resistive touchscreen will be optimal for a device that needs to remain accurate only for a few thousand actuations. In contrast, if the device will require significantly more usage, a 5-wire touchscreen is a better choice. However, a projected capacitive screen would be ideal if a display handles millions of actuations, as it can maintain its accuracy over infinite inputs.

Things-To-Consider-When-Choosing-A-Touchscreen-Technology

9. Final Words

All the above questions are a great start, and this is far from a comprehensive list of variables to consider when deciding on the optimal touchscreen technology. Please schedule a consultation with our experts to discuss your project requirements and custom solutions.

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Top 3 The Most Common Problems With Liquid Crystal Display

Top-3-The-Most-Common-Problems-With-Liquid-Crystal-Display

Outlines:

  1. What are the most common problems with LCDs displays?
  2. Fixing stuck pixels
  3. Fixing LCD residual images
  4. Broken pixels
  5. What Are The Five Key Lcd Display Challenges You Can Face?
  6. What To Pay Attention To When Using The Module?
  7. Final Words

1. What Are The Three Most Common Problems With LCDs Displays?

LCDs can suffer from the following three problems that can be irritating to have on your screen:

  • Stuck pixels, 
  • Broken pixels, 
  • Residual image

Here are some strategies to fix these problems if they occur.

2. Stuck Pixels

LCDs are composed of a fixed grid of tricolor pixels that change transparency based on the display’s controller’s range of voltage levels. The pixel is opaque without a voltage and blocks the screen’s backlight from transferring through it. And when a full voltage is applied, the pixel allows the total transmittance of the backlight. When this is done over the entire pixel grid in patterns, you see those patterns on the screen.

At an elementary level, the way pixels work is a voltage change alters the pixel to allow more or less light through it. No light is let through when there is no voltage. When the voltage is at its maximum level, a hundred percent of the light can pass through it. By supplying intermediate voltages, the computer adjusts the pixel’s transmittance levels for its three color components to show various combined colors and intensities.

stuck-pixels-problem-with-LCDs-displays

Fixing Stuck Pixels

One of the more common problems with LCDs is the potential for stuck pixels, where the pixel does not receive a voltage and remains black. Or it does not respond to voltage changes and stays at a set luminance level. 

When stuck pixels occur, you can try several things to fix the problem. One is to apply a small amount of pressure to the pixel when turning the display on or off, which can help stimulate the electronic devices to work correctly.

The alternative to using pressure is to exercise the pixel’s electronics by using a program that displays quick-changing patterns on the screen and rapidly switches the pixels on and off. Remember that fixing stuck or dead pixels can be a hit-or-miss process, so do not be surprised if a broken pixel does not come back to life.

fixing-stuck-pixels-problem-with-LCDs-displays

3. LCD Residual Images

Another problem called “transient persistence” is also affected by LCDs, reminiscent of CRT burn-in. Classic burn-in would happen due to the phosphor coating on the screen, and it would get depleted by the persistent bombardment of electrons from the CRT. These things result in the inability of those sections of the display to convert the electron beam to visible light. 

This meant that if you kept a specific pattern showing on the screen, it could become a permanent residual image on display over time that would show even when the display was off. That’s why screensavers were developed to keep the wear on the screen’s phosphor coating as even as possible.

The physical burn-in of displays is no longer an issue now that LCDs have taken over. Still, while transient image persistence is not a physical burn of the device, it alters the pixel response to voltage changes, preventing pixels from getting as bright as others on the screen.

LCD image persistence generally happens after you have displayed a pattern of intense colors on the screen. 

LCD-residual-images-problem-with-LCDs-displays

Fixing LCD Residual Images

LCD persistence can sometimes set in after only a few hours of displaying the image, instead of the weeks or even months it can take for the burn to set in on a CRT display. Additionally, image persistence is reverse-able.

What happens with LCDs is the affected pixels have lost their ability to respond to the full range of voltages that the display gives them, resulting in a limited range of colors that can be output. This can happen if the pixel cannot reach the level of luminance desired when given a specific voltage or acts as a capacitor and retains a residual charge. Either way, the pixel cannot get its full range of possible intensities.

Image persistence will benefit from a lengthy stretching of the pixel’s range, you might place a pure white window over the affected area for a few hours or even a few days if necessary, and this will force those pixels to be fully on and over time their intensities may increase to be the same as the surrounding pixels.

Likewise, try turning off the pixels fully by shutting down the display for an extended period or placing a pure black texture over the affected area (see the LCD Repair tool listed above for this option as well). This will turn the pixels entirely off and allow residual voltage in them to drain slowly over time.

Fixing-LCD-residual-images-problem-with-LCDs-displays

4. Broken Pixels

The system’s backlight can also suffer some common issues: 

  • The backlight randomly blinking off, 
  • Not turning on, 
  • Only illuminating part of the screen.

When the display entirely cuts out and does not show any light, one possibility could be that your computer is not correctly communicating with the display, or the display’s controllers or power supply is not working correctly. If this happens, try connecting the display to another system to avoid this issue.

broken-pixels-problem-with-LCDs-displays

Fixing Broken Pixels

If only the backlight is broken down, then the LCD panel itself should be working or rendering the text and images of your computer’s output is just fine. Use a bright flashlight to test for this and shine it on your screen at an angle in an area where you expect images and text. 

If shining an alternative light source on display causes graphical content to show up, then either the backlight or some component involved in controlling it has failed. It will likely need to be replaced, especially if you cannot rectify the problem by restarting the system, resetting PRAM and SMC, or toggling different hardware and software settings on your system.

fixing-broken-pixels-problem-with-LCDs-displays

5. Five Key LCD Display Challenges You Can Face

There are five most common problems with LCDs you can experience with them. Five simple words that can equate to significant LCD challenges for you are listed here. 

  • Obsolescence
  • Delivery
  • Quality
  • Performance
  • Cost

6. What To Pay Attention To When Using The Module?

We will encounter various problems when we produce and use LCD modules, among which the essential points are following: 

  1. Guarantee that the liquid crystal is not damaged by knocking; 
  2. Ensure that there is no dark area in the light-emitting area of the backlight; 
  3. Make sure that the capacitor resistance and IC on the PCB board are fused to the corresponding position stably. 

7. Conclusion

To avoid all the above-discussed problems, consider that choosing the right supplier based on your volume and quality needs is very important for you. Then implementing the optimal LCD solution with the optimal features and performance is essential.  

We strongly encourage our clients to reach out to us if they are developing a new product that requires a display or holds one or more of these problems.

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