BenQ Th681 Digital Projector User Manual

Introduction 11
Remote control
1. POWER
Toggles the projector between standby 
mode and on.
2. Info
Shows the status information of the 
projector.
3. MENU/EXIT
Turns on the On-Screen Display (OSD) 
menu. Goes back to previous OSD menu, 
exits and saves menu settings.
4. Left
5. MODE/ENTER
Selects an available picture setup mode.
Activates the selected On-Screen Display 
(OSD) menu item.
6. ECO BLANK
Used to hide the screen picture.
7. Keystone/Arrow keys ( / Up,  /
Down)
Manually corrects distorted...

Introduction 12
Remote control effective range
The remote control must be held at an angle within 30 degrees perpendicular to the 
projectors IR remote control sensor(s) to function correctly. The distance between the 
remote control and the sensor(s) should not exceed 8 meters (~ 26 feet).
Make sure that there are no obstacles between the remote control and the IR sensor(s) on 
the projector that might obstruct the infra-red beam.
Replacing the remote control batteries
1. To open the battery cover, turn...

Positioning your projector 13
Positioning your projector
Choosing a location
Your projector is designed to be installed in one of four possible installation locations: 
Your room layout or personal preference will dictate which installation location you select. 
Take into consideration the size and position of your screen, the location of a suitable 
power outlet, as well as the location and distance between the projector and the rest of 
your equipment.1. Front Table
Select this location with the...

Positioning your projector 14
Obtaining a preferred projected image size
The distance from the projector lens to the screen, the zoom setting, and the video format 
each factors in the projected image size.
Projection dimensions 
Installation for a 16:9 ratio screen
 The screen aspect ratio is 16:9 and the projected picture is in a 16:9 aspect ratio




Floor Installation
: Screen             : Center of lens
 
 

Ceiling Installation
: Screen             : Center of lens
Screen dimensionsProjection...

Positioning your projector 15
Installation for a 4:3 ratio screen
The illustrations and table below are provided for those users who already have 4:3 aspect 
ratio screens or intend to purchase 4:3 aspect ratio screens to view 16:9 ratio projected 
images.
 The screen aspect ratio is 4:3 and the projected picture is in a 16:9 aspect ratio
All measurements are approximate and may vary from the actual sizes. 
BenQ recommends that if you intend to permanently install the projector, you should physically...

Connection 16
Connection
When connecting a signal source to the projector, be sure to:
1. Turn all equipment off before making any connections.
2. Use the correct signal cables for each source.
3. Ensure the cables are firmly inserted.
•  In the connections shown below, some cables may not be included with the projector (see Shipping 
contents on page 8). They are commercially available from electronics stores.
•  The connection illustrations below are for reference only. The rear connecting jacks...

Connection 17
•  If you wish to use this connection method when the projector is in standby mode, make sure the 
Monitor Out function is turned on in the SYSTEM SETUP: Advanced menu. See Standby Settings 
on page 45 for details.
Connecting video source devices
You need only connect the projector to a video source device using just one of the 
connecting methods, however each provides a different level of video quality. The method 
you choose will most likely depend upon the availability of matching...

Operation 18
Operation
Starting up the projector
1. Plug the power cord into the projector and into a 
power outlet. Turn on the power outlet switch 
(where fitted). Check that the POWER indicator 
light on the projector lights orange after power 
has been applied.
Please use the original accessories (e.g. power cord) only with the 
device to avoid possible dangers such as electric shock and fire.
2. Press  POWER to start the projector. As soon as the lamp lights up, a Pow e r  
On Ring Tone will be...

Operation 19
Adjusting the projected image
Adjusting the projection angle
The projector is equipped with 1 quick-release adjuster foot and 1 rear adjuster foot. 
These adjusters change the image height and projection angle. To adjust the projector:
1. Press the quick-release button and lift the 
front of the projector. Once the image is 
positioned where you want it, release the 
quick-release button to lock the foot in 
position.
2. Screw the rear adjuster foot to fine-tune the 
horizontal angle.
To...

Operation 20
Correcting keystone
Keystoning refers to the situation where the projected image is noticeably wider at either 
the top or bottom. It occurs when the projector is not perpendicular to the screen. 
To correct this, you will need to manually correct it following ONE of these steps.
•  Press  /  on the projector or remote 
control to display the Keystone correction page. 
Press   to correct keystoning at the top of 
the image. Press   to correct keystoning at 
the bottom of the image.
•  Using...