在光存储，CLV（Constant linear velocity，恒定线性速度、恒定线速度、恒线速度、等线速度）是用于光盘驱动器的额定转速限定符，并且还可以应用到可刻录光盘的写入速度。CLV意味着角速度（即RPM）在操作过程中发生变化，与CAV模式对比。恒定线速度的概念被留声机先驱奇切斯特贝尔和查尔斯泰恩特于1886年申请了专利。

In optical storage, constant linear velocity (CLV) is a qualifier for the rated speed of an optical disc drive, and may also be applied to the writing speed of recordable discs. CLV implies that the angular velocity (i.e. rpm) varies during an operation, as contrasted with CAV modes. The concept of constant linear velocity was patented in 1886 by phonograph pioneers Chichester Bell and Charles Tainter.