The ultrasonic misfeed detector (also called the multi-pick or multi-feed detector) is a very useful feature included on several HP Scanjet models that can detect when multiple pages are fed simultaneously into the ADF (automatic document feeder) or sheet-feed scanner, alert the user, and stop the scanning job so the proper action can be taken. By default this feature is turned on so that it automatically improves the scanning experience and results.
However, in some cases when certain types of paper or media are being scanned, the detector will falsely identify a multi-feed issue and prevent proper scanning of those documents. The media affected in these cases is usually thicker than normal; such as heavier papers, business cards, and plastic identification (ID) cards. This document describes these situations and solutions to avoid these problems.
Certain papers and media are thick enough that the ultrasonic detection technology will falsely identify that two or more sheets have fed together into the scanner when only one has actually been picked. Examples of media that will trigger these false detections are business cards, plastic ID cards, and heavier stock paper. In addition, a multi-feed will be detected if a page has something attached to it, such as a sticky note.
When a false detection occurs, the scanner and/or the software will display an error message indicating that a paper jam or a multi-feed has occurred.
Two examples of the software message are shown in the Figures below:
Figure : SDSS misfeed error message
Figure : TWAIN misfeed error message
In scanners with the HP Smart Document Scan Software (SDSS) solution previous to version 3.1 note that a paper jam message can be the result of several different conditions, but one of them is the detection of a multi-feed. When troubleshooting a recurring paper jam problem it is important to consider that the ultrasonic misfeed detector may be triggering the problem and the resolution will involve changing the setting of the detection mechanism.
How to change the setting depends on the scanner model and software solution being used. The following sections address each of the possible scenarios.
HP Scanjet Models Using the HP Smart Document Scan Software (SDSS)
When trying to avoid a false detection with a scanner that uses SDSS it is necessary to edit the profile being used and look at the setting in the Hardware Options of the Scan Settings tab(see Figure 3 below). This section contains the control for turning the detection mechanism on and off. False detection can only be avoided by turning off the detection feature.
Figure : Selecting Misfeed detection in SDSS
In SDSS version 3.1 and later this feature will automatically be turned off when setting up a profile to scan a small page size (e.g. smaller than 4 inches/ 10cm in height) to avoid false detection problems in business cards and ID cards.
Some scanner models offer an additional control for misfeed detection (also shown in the above Figure). An exclusion region can be defined so that the detector can be used for improved scanning results by avoiding the false detection of pages that have a sticky note attached in that region of the page.
HP Scanjet Models Using an HP TWAIN or ISIS Driver
As with the SDSS solution, controls exist in the TWAIN and ISIS drivers to manage the misfeed detection. This control is available in the Hardware Options section of the Scan Settings tab (see Figure 4 below). Once again, if the scanner is falsely detecting a multi-pick and presenting a paper jam message it will be necessary to turn off the detection feature or, if available, define an exclusion region.
Figure : Selecting Multi-feed detection in the TWAIN driver
HP Scanjet 3000 Solution
The Scanjet 3000 scanner has its own unique software solution. The user interface is different to that shown in the previous sections but does include the ability to turn the misfeed detection on and off (see Figure 6). If the message shown in Figure 5 below is displayed, try turning off the misfeed detection feature in case the problem is due to a false detection.
Figure : Error message for Scanjet 3000 software
The settings can be most easily found by clicking on the Configure icon installed on the computer’s desktop (or from the Windows Start menu) and selecting the Process tab.
Figure : Scanjet 3000 software settings
The setting in this software is called Automatically detect multi-feeds using the Ultrasonic detection and works in the same way as the feature described previously. To avoid false detections turn this setting off.
When using the TWAIN driver for the HP Scanjet 3000 the user interface is different but the setting is still available (see Figure 7 below). In this case the setting is called Ultrasonic Detection and serves the same function.
Figure : Scanjet 3000 TWAIN settings
When using the TWAIN driver the error message is very specific and clear regarding a misfeed (see Figure 8 below). If this message is displayed and a multi-feed did not occur then consider that a false misfeed may have been detected and turn the feature off.
Figure : Misfeed detected using Scanjet 3000 TWAIN driver
The TWAIN driver also has a setting to Stop scanning after multi-feed. If this option is selected then the scanning operation will stop with a misfeed in the same way as the other HP scanner models behave. When the option is unchecked then the scan job will proceed even if a misfeed occurs and after the document completes scanning a summary will be displayed showing the number of mis-feeds detected (see Figure 9 below).
Figure : Scanjet 3000 multi-feed count
HP Network Scanners with FutureSmart Firmware (Scanjet 7000n/7000nx/8500 fn1)
The Scanjet 7000n/7000nx and Scanjet 8500 fn1 also include an ultrasonic misfeed detector and clearly indicate when such an event occurs (see Figure 10 below).
Figure : Misfeed error message on a FutureSmart scanner
As with the scanners mentioned above, these scanners are also susceptible to the false detection and have the ability to turn off the detection feature in order to avoid the problem. There are two ways to change this setting: in the HP Embedded Web Server (EWS) and from the Control Panel of the device.
The EWS has mechanisms for turning the misfeed detection feature on and off for both the default behavior and the definition of a Quick Set. In both cases there is a check box in the Scan Settings section that needs to be unchecked to avoid the false detection. The Figure below shows an example of the EWS setting for the Save to Network Folder default behavior.
Figure : Misfeed detection feature on EWS for Scanjet 8500 fn1
If the default or the Quick Set setting has misfeed detection enabled, it is possible to turn off the feature for a specific scan job by using the Control Panel. When initiating the scan job press on the More Options down arrow several times until the screen shown in Figure 12 below is displayed. Note that in this Figure Misfeed Detection is enabled. Touch on the Setting, select Disable, and then proceed with the scan job.
Figure : Control Panel with misfeed detection feature
