Added more info.

unsupported/hp-scanjet-3970c.html

@@ -39,6 +39,10 @@
       3570c</a>. At least the functinality is the same, only the resolution is
       higher.
     </p>
+    <p>
+      The Manual also mentions these scanners: HP Scanjet 2400, HP Scanjet 3670,
+      HP Scanjet 3690.
+    </p>
     <h2>Output of /proc/bus/usb/devices or sane-find-scanner -v -v</h2>
     <pre>
 T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 15 Spd=12  MxCh= 0