CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 56,151	$ 45,843
Short-term investments	21,912	21,689
Receivables (net of allowances of $287 at June 30, 2012 and $283 at March 31, 2012)	29,038	30,694
Inventories	20,940	19,597
Prepaid expenses and other current assets	3,670	5,423
Net deferred tax assets, current	4,328	4,151
Total current assets	136,039	127,397
Long-term investments	20,129	23,442
Investment in unconsolidated affiliate	2,643	2,626
Property and equipment, net	25,165	24,296
Intangible assets, net	3,832	3,990
Other assets	109	85
Total assets	187,917	181,836
Current liabilities:
Accounts payable	7,553	6,381
Accrued payroll and related expenses	6,821	6,336
Accrued taxes	144	266
Other accrued liabilities	1,806	1,991
Deferred revenue	1,307	1,212
Warranty reserve	1,012	1,245
Total current liabilities	18,643	17,431
Non-current liabilities:
Deferred rent	669	641
Net deferred tax liabilities	197	199
Deferred revenue	2,708	2,396
Warranty reserve	482	601
Notes payable, less current portion	758	783
Total non-current liabilities	4,814	4,620
Total liabilities	23,457	22,051
Commitments and contingencies (Note 9)
Shareholders' equity:
Preferred stock, no par value: 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, no par value: 35,000,000 shares authorized; 21,888,000 and 21,699,000 shares issued and outstanding at June 30, 2012 and at March 31, 2012, respectively	111,878	110,063
Retained earnings	52,561	49,697
Accumulated other comprehensive income	21	25
Total shareholders' equity	164,460	159,785
Total liabilities and shareholders' equity	$ 187,917	$ 181,836