多点触控如何工作？通过。分行教育 How does Multitouch work? By. Branch Education
您是否想过智能手机的多点触摸屏 Have you ever thought of your smartphone’s multitouch screen
在功能上类似于您的身体皮肤？ as functionally similar to your body’s skin?
在这里待在我身边：两个人都能感应到多个触摸， Stay with me here: both are able to sense multiple touches,
然后两者都能做出决定并根据这些输入采取行动。 and then both are able to make decisions and act on those inputs.
我们认为能够感受到周围的环境是理所当然的 We take for granted being able to feel and sense the environment around us
但是将这些感官转化为电子设备 but translating these senses to electronic devices and
建立类似多点触控的功能并非易事。 building something like multi touch is no trivial task.
在此分支集中，我们将讨论工程师 In this branch episode we are going to discuss how engineers
创建的屏幕可以识别智能手机中的多次触摸。 created screens that could discern multiple touches in smartphones.
此剧集是该剧集的一个分支，触摸屏显示器如何工作？ This episode is a branch of the episode how does a touchscreen display work?
它涉及投射电容式触摸屏背后的物理和基本结构 which goes into the physics and basic structure behind projected capacitive touchscreens
以及OLED显示器和钢化玻璃， as well as OLED displays and toughened glass,
因此，如果您还没看过，我建议您看看。 so I recommend you take a look if you haven’t seen it.
*简介音乐* *Intro Music*
好吧，让我们开始吧！ Ok, so let's dive in!
该触摸屏由40列蓝色的行组成 This touch screen is made of 40 rows colored in blue
黄色的80列 and 80 columns colored in yellow
结果是一个拥有超过3000个相交点的网格， The result is a grid with over 3 thousand intersections,
并且您的手机可以在每个交叉路口感应到触摸。 and your phone can sense a touch at each of those intersections.
我们将在短期内探讨其操作方式，但现在- We’ll get into how it does that shortly, but for now-
当您键入一条消息时，您的手机会检测到一种类似以下的模式。 when you type out a message, your phone detects a pattern that looks like this.
向右滑动时，手机会检测到此情况，并且多点触控变焦看起来像这样。 When you swipe right, your phone detects this, and multi touch zooms look like this.
即使手指较大，智能手机也可以找到触摸中心。 Even if you have large fingers, your smartphone can find the center of your touch.
它可以看到水龙头或手势的大小，形状和位置 It can see the size, shape and location of the tap or gesture
然后计算X和Y坐标。它还可以确定您是否离开了手指 and then calculates the X, and Y coordinates. It also determines whether you left your finger
或手指在屏幕上的滑动以及是否向任何特定方向滑动。 or fingers on the screen and if you swiped in any particular direction.
让我们快速回顾一下屏幕如何在一个路口检测到触摸。 Let’s quickly review how the screen detects a touch at one intersection.
带负电荷的电子被施加到蓝色板上 Electrons with a negative charge are applied to the blue plate
它会产生一个电场并使正电荷聚集在黄板上。 which builds an electric field and causes positive charges to gather on the yellow plate.
当指尖等导电材料接近时， When a conductive material like your finger tip comes close,
它会中断电场，并测量黄板上的正电荷变化。 it interrupts the electric field and the change in positive charge on the yellow plate is measured.
您可能想知道我的触摸屏如何通过玻璃和屏幕保护膜工作。 You might be wondering how does my touchscreen work through the glass and screen protector.
好吧，这种触摸屏称为投射电容式触摸屏 Well, this type of touchscreen is called a projected capacitive touchscreen
因为电场上升到玻璃表面上方， because the electric field rises above the surface of the glass,
因此触摸屏将通过保护盖工作 so the touchscreen will work through protective covers
以及薄的塑料或橡胶手套。测试一下！ as well as thin plastic or rubber gloves. Test it out!
抓住一些塑料袋或萨兰包装 grab a few plastic bags or saran wrap
并查看您的触摸屏可以感知多少层塑料。 and see how many layers of plastic your touchscreen can sense through.
在继续之前，让我们从32个交叉点简化网格 Before we continue, let's simplify the grid from thirty two hundred intersections
下降到两百个路口 down to two hundred intersections.
一切在概念上都相同，只是更容易可视化。 Everything conceptually works the same, it's just easier to visualize.
好吧-所有行都带负电并建立了电场， Ok- so with all the rows charged negatively and the electric fields built up,
色谱柱会主动测量以观察电场的变化， and the columns actively measuring to see changes in the electric field,
我们有触摸屏，对不对？好吧，不完全是。 we have a touchscreen, right? Well not exactly.
看，我们是否持续测量这些列中的每列 See, if we continuously measure each of these columns
当所有行的电场都处于活动状态时，我们遇到了一些问题。 while all the rows of electric fields are active, we run into a few issues.
说我点击这里。好吧，因为整个黄色列都已连接， Say I tap here. Well, because the entire yellow column is connected,
无法区分是在这里还是在这里。 it can’t distinguish whether there was a tap here, or here.
这不是一个好的触摸屏。我们必须同时测量整列 This is not a good touch screen. We have to measure the entire column simultaneous,
因为如果我们分解色谱柱并测量单个钻石， because if we break up the column and measure individual diamonds,
我们最终将测量3200点，那就太多了。 we will end up measuring thirty-two hundred points, and that is too many points.
那么我们如何才能使其正常工作？ so then how do we get it to work properly?
嗯，工程师实施的解决方案是扫描或 Well, the solution that engineers implemented was to scan or
快速沿行扫掠电场 sweep the electrid field along the rows veerrryy quickly
-每行约10微秒的速率。在任何给定时间，只有一行 - at a rate of about 10 microseconds per row. At any given time only one row is on,
因此一次只有一排交叉路口可以检测到触摸。 thus only one row of intersections can detect a touch at a time.
智能手机中的电路控制着每一行的电场扫描， Circuitry in the smartphone controls this sweep of the electric field across each of the rows,
并且在每一行记录沿每一列的测量值。 and at every row a measurement along each column is recorded.
在电场移至下一行之前，每列都会重置其测量值。 Before the electric field moves to the next row, each column resets its measurement.
然后，当行处于活动状态时，智能手机进行关联 The smartphone then correlates when the row was active
每个列的输出，以重建完整的网格。 with the output of each column in order to reconstruct a complete grid.
此扫描发生在几毫秒内 This scanning happens within a couple millisconds
并且允许智能手机在3次或更多次触摸之间进行区分 and it allows for the smartphone to distinguis between 3 or more touches
在所有不同的位置。缺点是引入了新的时间延迟 in all different locations. The drawback is that a new time delay is introduced
如果触摸屏太大，请说一张小桌子的大小， and if the touchscreen gets too big, say the size of a small table,
扫描这么多行会产生相当明显的延迟。 there would be a rather noticeable delay from the scanning across so many rows.
但是，使用智能手机大小的触摸屏， However, with a touchscreen the size of your smartphone,
它可以快速确定所有类型的触摸和手势。 it can quickly determine all types of touches and gestures.
这几乎可以总结为智能手机中的多点触控 That pretty much sums it up for multi touch in your smartphone
还有许多其他类型的触摸屏，例如电阻式或自电容式触摸屏 There are many other types of touchscreens like resistive, or self-capacitive touchscreens
在其他情节中有详细说明。此剧集与触摸屏显示器的结构有关 to be detailed in other episodes. This episode is related to the structure of a touchscreen display
以及电场和电容器。以及如何测量电容 as well as electric fields, and capacitors. And how to measure capacitance
感谢收看！不要忘记订阅，评论您的问题和想法， Thanks for watching! Don’t forget to subscribe, comment with your questions and thoughts,
并告诉您的朋友和家人您今天所学到的东西。 and tell your friends and family about something you learned today.
并记住要考虑概念上的简单性和结构复杂性。 And remember to think about conceptual simplicity and structural complexity.
谢谢！ Thanks!