Business activities and summary of significant accounting policies - Additional Information (Detail) (USD $)	12 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Amortized intangible assets		$ 81,000
Advertising costs charged to operations	242,000	244,000
Research and development costs charged to operations	470,000	622,000
Stock based compensation expense	263,935	312,311
Shares excluded from computation of diluted per share amount	755,568	590,968
Stock Options
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expense	264,000	312,000
Cost of Sales
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expense	53,000	61,000
Selling General and Engineering Expenses
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expense	$ 211,000	$ 251,000
VIE Building
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Cost and depreciated over their estimated useful lives	39 years
Minimum
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Cost and depreciated over their estimated useful lives	3 years
Maximum
Business Activities and Summary Of Significant Accounting Policies [Line Items]
Cost and depreciated over their estimated useful lives	7 years