It's really a GL646.

unsupported/plustek-opticpro-st24.html

@@ -32,7 +32,8 @@
     </p>
     <h2>Chipset</h2>
     <p>
-      Probably <a href="http://www.genesyslogic.com/GL646.htm">Genesys GL646</a>.
+      It's a <a href="http://www.genesyslogic.com/GL646.htm">Genesys
+	GL646</a>. 
     </p>
     <h2>Comments</h2>
     <p>
@@ -42,7 +43,7 @@
     </p>
     <h2>Output of /proc/bus/usb/devices or sane-find-scanner -v -v</h2>
     <pre>
-(ST24)
+(ST24):
 T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#=  3 Spd=12  MxCh= 0
 D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
 P:  Vendor=07b3 ProdID=0601 Rev= 0.00
@@ -53,6 +54,9 @@ I:  If#= 0 Alt= 0 #EPs= 3 Cls=10(unk. ) Sub=01 Prot=00 Driver=(none)
 E:  Ad=81(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms
 E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
 E:  Ad=83(I) Atr=03(Int.) MxPS=   1 Ivl=8ms
+
+(ST24):
+found USB scanner (vendor=0x07b3 [PLUSTEK INC], product=0x0601 [USB SCANNER], chip=GL646) at libusb:001:003
     </pre>
     
     <h1>Want to add or correct information?</h1>