1.照相机与眼睛
1.1照相机的原理:利用凸透镜成缩小实像的原理制成(u>2f),如图所示;
![](https://static.hongwu.com/images/2024/04/15/2194488_6894ace054d0495cb78160037b951af7~noop_gos0hdyeyrs.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_5f91eae7bd3649af91c0783a34286ce6~noop_ofdt5ty4dav.jpg)
1.2眼睛的原理:利用凸透镜成缩小实像的原理。
![](https://static.hongwu.com/images/2024/04/15/2194488_1318ceda949042c195af787c2cb78ca7~noop_4w42nomvfuc.jpg)
1.3眼睛与照相机对比,相似功能如下表:
![](https://static.hongwu.com/images/2024/04/15/2194488_b77e37ae3a184a5094c4529204d3a959~noop_difn0wo1jx1.jpg)
1.4视力缺陷与矫正
1.4.1正视眼图
![](https://static.hongwu.com/images/2024/04/15/2194488_ad7d68c870d74d47bfce1bd132ae47fb~noop_seadb4kdyt5.jpg)
1.4.2近视眼:
①特征:看不清远处的景物;
②形成原因:经过调节晶状体的厚薄后,远处物体的像仍落在视网膜的前方;
③矫正方法:可用凹透镜的镜片来矫正,如下图所示:
![](https://static.hongwu.com/images/2024/04/15/2194488_ed847bbacdbe413e9be2f0017c597a0f~noop_uqpznfsy0ne.jpg)
1.4.3远视眼:
①特证:看不清近处的物体;
②形成原因:经过调节晶状体的厚薄后,远处物体的像仍落在视网膜的后面;
③矫正方法:可用凸透镜的镜片来矫正,如下图所示。
![](https://static.hongwu.com/images/2024/04/15/2194488_4fd9b42f5b2c45a6b8244e01df8893e9~noop_knmphwcjnuo.jpg)
2.放大镜与幻灯机
2.1放大镜原理:将观察物体放在凸透镜的焦点以内(u<f),使之成正立、放大的虚像;如下图所示
![](https://static.hongwu.com/images/2024/04/15/2194488_88d1a1c6a0424a56a82dad0cbdbdfed4~noop_yxhkfnvpbwt.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_a881f479c39d4f8487261d0d5c8f0513~noop_yttp4wlvqry.jpg)
2.2幻灯机原理:利用凸透镜成倒、放大的实像(f<u<2f),如下图所示。
![](https://static.hongwu.com/images/2024/04/15/2194488_4a4bbd7b5aad4e40b27b7700385cf871~noop_vstwlwni2rr.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_66816e8e675c4b359a54f18858dcc216~noop_4h1xsp3f25v.jpg)
注意:为了使屏幕上能看到正立的像,注意透明胶片的放置方向。
3望远镜与显微镜
![](https://static.hongwu.com/images/2024/04/15/2194488_c5eb5aa458c249bea7564cd712db0893~noop_ew3jd0x2vhn.jpg)
3.1望远镜
3.1.主要组成:通常的望远镜是由两个透镜组成,其中靠近眼睛的透镜叫目镜,焦距较短,靠近被观察物体的透镜叫物镜,焦距较长;
![](https://static.hongwu.com/images/2024/04/15/2194488_711108dc1a094abd8dfbd4a0ca7a542b~noop_v3wvxdetcb1.jpg)
3.1.2成像原理:望远镜观察远处物体时,来自远处物体的光经物镜后成一个缩小的实像(u>2f),这个缩小的实像在目镜的焦点以内,目镜的作用相当于一个放大镜(u<f),把这个缩小的像放大。
![](https://static.hongwu.com/images/2024/04/15/2194488_a4a782eac86d415e8ab180bde4b83055~noop_e3qilvqnxom.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_48bf12ff45a5442cb386e48b62376f67~noop_owrjjgotfe1.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_995c2aca85de47dda365a2cd135ffaf3~noop_0srtjbzw3zr.jpg)
![](https://static.hongwu.com/images/2024/04/15/2194488_e6b21e8a7ac846858ec368a2f94e161e~noop_ezt2bixv41y.jpg)
3.2显微镜
3.2.1主要组成:焦距很短的凸透镜作为物镜,焦距较长的凸透镜作为目镜;
![](https://static.hongwu.com/images/2024/04/15/2194488_3a171179ce7c480eb5e1c6c521c03c12~noop_ys4llz53qwx.jpg)
3.2.2成像原理:物体位于物镜的一倍焦距和两倍焦距之间,成倒立放大实像,此像又位于目镜的焦点之内,经过目镜成正立放大虚像。
![](https://static.hongwu.com/images/2024/04/15/2194488_0353c99ec18d41acbd6e36a74dd2b953~noop_53kcotkrhkt.jpg)
附:
![](https://static.hongwu.com/images/2024/04/15/2194488_4f545b4c2b9a47a093ad3c62ac058edc~noop_qpqdlqfxk4v.jpg)