Yes, actually there are several different delays involved with interfacing a Hitachi LM020L and same is true with every LCD or GLCD. Whenever you begin the job of designing a new circuit, you should always collect the relevant datasheets for the components you have incorporated in your design. This procedure reduce stress and aspirin intake during the design process.
Here's the LM020L datasheet, it's an old scanned version, you could of found an equivalent LCD based on the HD44780 chipset, most of this style LCD are by the way:
Hitachi LM020L
Check it out it's amazing the handy information included in a component datasheet.
What's even more amazing is people attempting to actually design a viable circuit without even a glimpse of the components' datasheets used in their design.
Hope the info helps in your endeavors.