How to stop Tablet sleeping

[Android Question]

Have an Ainol Novo 7 Venus (no carrier). Often, when I turn the screen off the tablet after about half an hour goes into deep sleep mode. to re-boot it then requires an eight second press on the power button. Usually it only needs three seconds. Iv'e been everywhere but I can't find a place to disable sleep mode.
Hope you can help.
Ron Heggie

 

[ErinGoBragh]

Why do you want to disable this? Sleep modes are generally there to lengthen battery life and protect devices from heat damage (if devices don't sleep and are placed in a enclosed/insulated environment such as in a bag or on a bed, they can overheat). You can look in your power settings but you may want to reconsider disabling this feature.