BenQ Th681 Digital Projector User Manual

							Operation 21
Using the menus
The projector is equipped with On-Screen Display (OSD) menus for making various 
adjustments and settings.
The OSD screenshots below are for reference only, and may differ from the actual design.
Below is the overview of the OSD menu.
The following example describes how to set the OSD language.
1. Press MENU/EXIT on the projector or 
remote control to turn the OSD menu on.3. Press  to highlight Language 
and press MODE/ENTER. 
2. Use  /  to highlight the SYSTEM 
SETUP: Basic menu.4. Press  / / /  to select a 
preferred language.
5. Press MENU/EXIT on the 
projector or remote control to 
leave and save the settings.
Current input signal
Main menu icon
Main menu
Sub-menu
Highlight
Press MENU/
EXIT to the 
previous 
page or to 
exit. Status
DISPLAYWall Color
Aspect Ratio
Keystone
Position
Phase
H. Size
Digital ZoomOff
Auto
0
0
ENTER
MENU Exit
Analog RGB
3D
Teaching Template
DISPLAYWall Color
Aspect Ratio
Position
Phase
H. Size
Digital ZoomKeystone
Analog RGBOff
Auto
0
0
MENU Exit
3D
Teaching Template
SYSTEM SETUP: BasicPresentation Timer
Language
Projector Installation
Operation Settings
Panel Key Lock
Splash Screen Background Color
Analog RGB
MENU Exit
Front Table
Off
BenQ
BenQMenu Settings
Remote ReceiverFront+Top
ENTER
SYSTEM SETUP: BasicPresentation Timer
Language
Projector Installation
Operation Settings
Panel Key Lock
Splash Screen Background Color
Analog RGB
MENU Exit
Front Table
Off
BenQ
BenQ Menu Settings
Remote ReceiverFront+Top 
						

							Operation 22
Securing the projector
Using a security cable lock
The projector has to be installed in a safe place to prevent theft. Otherwise, purchase a 
lock, such as the Kensington lock, to secure the projector. You can locate a Kensington 
lock slot on the rear side of the projector. See item 23 on page 9 for details.
A Kensington security cable lock is usually a combination of key(s) and the lock. Refer to 
the lock’s documentation for finding out how to use it.
Utilizing the password function
For security purposes and to help prevent unauthorized use, the projector includes an 
option for setting up password security. The password can be set through the On-Screen 
Display (OSD) menu.
WARNING: You will be inconvenienced if you activate the password functionality and subsequently forget the 
password. Print out this manual (if necessary) and write the password you used in this manual, and keep the 
manual in a safe place for later recall.
Setting a password
Once a password has been set and the power on lock is activated, the projector cannot be used unless the 
correct password is entered every time the projector is started.
1. Open the OSD menu and go to the SYSTEM SETUP: Advanced > Security 
Settings menu. Press MODE/ENTER. The Security Settings page appears.
2. Highlight Change Security Settings and press MODE/ENTER.
3. As pictured to the right, the four arrow keys 
(, , , ) respectively represent 4 digits 
(1, 2, 3, 4). According to the password you 
desire to set, press the arrow keys to enter six 
digits for the password.
4. Confirm the new password by re-entering the 
new password.
Once the password is set, the OSD menu 
returns to the Security Settings page.
5. To activate the Power On Lock function, press  /  to highlight Power On Lock 
and press  /  to select On.
IMPORTANT: The digits being input will display as asterisks on-screen. Write your selected password down 
here in this manual in advance or right after the password is entered so that it is available to you should you 
ever forget it.
Password: __ __ __ __ __ __
Keep this manual in a safe place.
6. To leave the OSD menu, press MENU/EXIT.
INPUT NEW PASSWORD
Back MENU 
						

							Operation 23
If you forget the password
If the password function is activated, you will be asked 
to enter the six-digit password every time you turn on 
the projector. If you enter the wrong password, the 
password error message as pictured to the right 
appears lasting for 3 seconds, and the INPUT 
PA S S WO R D message follows. You can retry by 
entering another six-digit password, or if you did not 
record the password in this manual, and you absolutely do not remember it, you can use 
the password recall procedure. See Entering the password recall procedure on page 23 
for details.
If you enter an incorrect password 5 times in succession, the projector will automatically 
shut down in a short time.
Entering the password recall procedure
1. Press and hold AUTO on the projector or 
remote control for 3 seconds. The 
projector will display a coded number on 
the screen.
2. Write down the number and turn off your 
projector.
3. Seek help from the local BenQ service 
center to decode the number. You may be 
required to provide proof of purchase 
documentation to verify that you are an 
authorized user of the projector.
Changing the password
1. Open the OSD menu and go to the SYSTEM SETUP: Advanced> Security 
Settings > Change Password menu.
2. Press MODE/ENTER. The message “INPUT CURRENT PASSWORD” 
appears.
3. Enter the old password.
i. If the password is correct, another message “INPUT NEW PASSWORD” 
appears. 
ii. If the password is incorrect, the password error message appears lasting for 
three seconds, and the message “INPUT CURRENT PASSWORD” appears 
for your retry. You can press MENU/EXIT to cancel the change or try another 
password.
4. Enter a new password.
IMPORTANT: The digits being input will display as asterisks on-screen. Write your selected password down 
here in this manual in advance or right after the password is entered so that it is available to you should you 
ever forget it.
Password: __ __ __ __ __ __
Keep this manual in a safe place.
5. Confirm the new password by re-entering the new password.
6. You have successfully assigned a new password to the projector. Remember to enter 
the new password next time the projector is started.
7. To leave the OSD menu, press MENU/EXIT.
Password Error
Please try again.
Please write down the recall code,
and contact BenQ
Customer Center.
Recall Code:
255   255   255   255
RECALL PASSWORD
Exit MENU 
						

							Operation 24
Disabling the password function
To disable password protection, go back to the SYSTEM SETUP: Advanced > 
Security Settings > Change Security Settings menu after opening the OSD menu 
system. Press MODE/ENTER. The message “INPUT PASSWORD” appears. Enter 
the current password. 
i. If the password is correct, the OSD menu returns to the Security Settings 
page.
Press   to highlight Power On Lock and press  /  to select Off. You will 
not have to enter the password next time when turning on the projector.
ii. If the password is incorrect, the password error message appears lasting for 
three seconds, and the message “INPUT PASSWORD” appears for your 
retry. You can press MENU/EXIT to cancel the change or try another 
password.
Though the password function is disabled, you need to keep the old password in hand should you ever need to 
re-activate the password function by entering the old password.
Switching input signal
The projector can be connected to multiple devices at the same time. However, it can only 
display one full screen at a time. When starting up, the projector automatically searches for 
the available signals.
Be sure the Quick Auto Search function in the SOURCE menu is On if you want the 
projector to automatically search for the signals.
To select the source:
1. Press SOURCE on the projector or remote 
control. A source selection bar appears. 
2. Press / until your desired signal is selected 
and press MODE/ENTER.
Once detected, the selected source information 
will display at the corner of the screen for 
seconds. If there is multiple equipment connected 
to the projector, repeat steps 1-2 to search for 
another signal.
•  The brightness level of the projected image will change 
accordingly when you switch between different input signals. 
Data (graphic) PC presentations using mostly static images 
are generally brighter than Video using mostly moving images 
(movies).
•  The native display resolution of this projector is in a 16:9 aspect 
ratio. For best display picture results, you should select and use 
an input signal which outputs at this resolution. Any other 
resolutions will be scaled by the projector depending upon the 
“aspect ratio” setting, which may cause some image distortion 
or loss of picture clarity. See Selecting the aspect ratio on 
page 25 for details.
Computer1/YPbPr1
Computer2/YPbPr2
HDMI
Video
S-Video
Network Display
USB Display
USB Reader 
						

							Operation 25
Changing Color Space
In the unlikely event that you connect the projector to a DVD player via the projector’s 
HDMI input and the projected picture displays wrong colors, please change the color 
space to YUV.
To  d o  t h i s :
1. Press MENU/EXIT and then press  /  until the SOURCE menu is highlighted.
2. Press   to highlight Color Space Conversion and press  /  to select a suitable 
color space.
This function is only available when the HDMI-input port is in use.
Magnifying and searching for details
If you need to find the details on the projected picture, magnify the picture. Use the 
direction arrow keys for navigating the picture.
•  Using the remote control
1. Press Digital Zoom+/- to display the Zoom bar. Press Digital Zoom+ to magnify 
the center of the picture. Press the key repeatedly until the picture size is suitable for 
your need.
2. Use the directional arrows ( ,  ,  ,  ) on the projector or remote control to 
navigate the picture.
3. To restore the picture to its original size, press AUTO. You can also press Digital 
Zoom-. When the key is pressed again, the picture is further reduced until it is 
restored to the original size.
•  Using the OSD menu
1.
Press MENU/EXIT and then press / until the DISPLAY menu is highlighted.
2. Press  to highlight Digital Zoom and press MODE/ENTER. The Zoom bar 
appears.
3. Press   repeatedly to magnify the picture to a desired size.
4. To navigate the picture, press MODE/ENTER to switch to the panning mode and 
press the directional arrows ( ,  ,  ,  ) on the projector or remote control to 
navigate the picture.
5. To reduce size of the picture, press MODE/ENTER to switch back to the zoom in/
out function, and press AUTO to restore the picture to its original size. You can 
also press   repeatedly until it is restored to the original size.
The picture can only be navigated after it is magnified. You can further magnify the picture while searching for 
details.
Selecting the aspect ratio
The “aspect ratio” is the ratio of the image width to the image height. Most analog TV and 
some computers are in 4:3 ratio, and digital TV and DVDs are usually in 16:9 ratio.
With the advent of digital signal processing, digital display devices like this projector can 
dynamically stretch and scale the image output to a different aspect than that of the image 
input signal.
To change the projected picture ratio (no matter what aspect the source is):
•  Using the remote control
1. Press Aspect to show the current setting. 
						

							Operation 262. Press Aspect repeatedly to select an aspect ratio to suit the format of the video 
signal and your display requirements.
•  Using the OSD menu
1. Press MENU/EXIT and then press  /  until the DISPLAY menu is highlighted.
2. Press
  to highlight Aspect Ratio.
3. Press  /  to select an aspect ratio to suit the format of the video signal and your 
display requirements.
About the aspect ratio
•  In the pictures below, the black portions are inactive areas and the white portions are active areas.
•  OSD menus can be displayed on those unused black areas.
1.Auto: Scales an image proportionally to fit 
the projectors native resolution in its 
horizontal or vertical width. This is suitable 
for the incoming image which is neither in 4:3 
nor 16:9 and you want to make most use of 
the screen without altering the images aspect 
ratio.
2.Real
: The image is projected as its original 
resolution, and resized to fit within the display 
area. For input signals with lower resolutions, 
the projected image will display smaller than if 
resized to full screen. You could adjust the 
zoom setting or move the projector towards 
the screen to increase the image size if 
necessary. You may also need to refocus the 
projector after making these adjustments.
3.4:3: Scales an image so that it is displayed in 
the center of the screen with a 4:3 aspect 
ratio. This is most suitable for 4:3 images like 
some computer monitors, standard definition 
TV and 4:3 aspect DVD movies, as it displays 
them without aspect alteration.
4.16:9: Scales an image so that it is displayed in 
the center of the screen with a 16:9 aspect 
ratio. This is most suitable for images which 
are already in a 16:9 aspect, like high definition 
TV, as it displays them without aspect 
alteration.
5.16:10: Scales an image so that it is displayed in 
the center of the screen with a 16:10 aspect 
ratio. This is most suitable for images which 
are already in a 16:10 aspect, as it displays 
them without aspect alteration.
15:9 picture
4:3 picture
16:9 picture
4:3 picture
16:9 picture
16:10 picture 
						

							Operation 27
Optimizing the image
Using Wall Color
In the situation where you are projecting onto a colored surface such as a painted wall 
which may not be white, the Wall Color feature can help correct the projected picture’s 
colors to prevent possible color difference between the source and projected pictures.
To use this function, go to the DISPLAY > Wall Color menu and press  /  to select 
a color which is closest to the color of the projection surface. There are several 
precalibrated colors to choose from: Light Yellow, Pink, Light Green, Blue, and 
Blackboard.
Selecting a picture mode
The projector is preset with several predefined picture modes so that you can choose one 
to suit your operating environment and input signal picture type.
To select an operation mode that suits your need, you can follow one of the following 
steps.
• Press MODE/ENTER on the projector or remote control repeatedly until your 
desired mode is selected.
•  Go to the PICTURE > Picture Mode menu and press  /  to select a desired 
mode.
1.Dynamic mode: Maximizes the brightness of the projected image. This mode is 
suitable for environments where extra-high brightness is required, such as using the 
projector in well lit rooms.
2.Presentation mode: Is designed for presentations. The brightness is emphasized in 
this mode to match PC and notebook coloring.
3.sRGB mode: Maximizes the purity of RGB colors to provide true-to-life images 
regardless of brightness setting. It is most suitable for viewing photos taken with an 
sRGB compatible and properly calibrated camera, and for viewing PC graphic and 
drawing applications such as AutoCAD.
4.Cinema mode: Is appropriate for playing colorful movies, video clips from digital 
cameras or DVs through the PC input for best viewing in a blackened (little light) 
environment.
5.3D mode: Is appropriate for playing 3D images and 3D video clips.
6.User 1/User 2 mode: Recalls the settings customized based on the current 
available picture modes. See Setting the User 1/User 2 mode on page 27 for details.
Setting the User 1/User 2 mode
There are two user-definable modes if the current available picture modes are not suitable 
for your need. You can use one of the picture modes (except the User 1/2) as a starting 
point and customize the settings.
1. Press MENU/EXIT to open the On-Screen Display (OSD) menu.
2. Go to the PICTURE > Picture Mode menu.
3. Press / to select User 1 or User 2.
4. Press  to highlight Reference Mode.
This function is only available when User 1 or User 2 mode is selected up in the Picture Mode sub-menu 
item.
5. Press / to select a picture mode that is closest to your need. 
						

							Operation 286. Press  to select a menu item to be changed and adjust the value with /. See 
Fine-tuning the image quality in user modes below for details.
Fine-tuning the image quality in user modes
According to the detected signal type and selected picture mode, some of the below 
functions may not be available. Based on your needs, you can make adjustments to these 
functions by highlighting them and pressing  /  on the projector or remote control.
Adjusting Brightness
The higher the value, the brighter the image. And the 
lower the setting, the darker the image. Adjust this 
control so the black areas of the image appear just as 
black and that detail in the dark areas is visible.
Adjusting Contrast
The higher the value, the greater the contrast. Use this 
to set the peak white level after you have previously 
adjusted the Brightness setting to suit your selected 
input and viewing environment.
Adjusting Color
Lower setting produces less saturated colors. If the setting is too high, colors on the image 
will be overpowering, which makes the image unrealistic.
Adjusting Tint
The higher the value, the more reddish the picture becomes. The lower the value, the 
more greenish the picture becomes.
Adjusting Sharpness
The higher the value, the sharper the picture becomes. The lower the value, the softer the 
picture becomes.
Adjusting Brilliant Color
This feature utilizes a new color-processing algorithm and system level enhancements to 
enable higher brightness while providing truer, more vibrant colors in picture. It enables a 
greater than 50% brightness increase in mid-tone images, which are common in video and 
natural scenes, so the projector reproduces images in realistic and true colors. If you 
prefer images with that quality, select On. If you don’t need it, select Off.
When Off is selected, the Color Temperature function is not available.
Selecting a Color Temperature
The options available for color temperature* settings vary according to the signal type 
selected.
1.Cool: Makes images appear bluish white.
2.Normal: Maintains normal colorings for white.
3.Warm: Makes images appear reddish white.
*About color temperatures:
There are many different shades that are considered to be white for various purposes. 
One of the common methods of representing white color is known as the “color 
temperature”. A white color with a low color temperature appears to be reddish white. A 
white color with a high color temperature appears to have more blue in it.
+50+30+70
0-30+30 
						

							Operation 29
Setting a preferred color temperature
To set a preferred color temperature:
1. Highlight Color Temperature and select Warm, Normal or Cool by pressing 
/  on the projector or remote control.
2. Press  to highlight Color Temperature Fine Tuning and press MODE/
ENTER. The Color Temperature Fine Tuning page appears.
3. Press  / to highlight the item you want to change and adjust the values by 
pressing / .
•R Gain/G Gain/B Gain: Adjusts the contrast levels of Red, Green, and Blue.
•R Offset/G Offset/B Offset: Adjusts the brightness levels of Red, Green, and 
Blue.
4. Press MENU/EXIT to exit and save the settings
3D Color Management
In most installation situations, color management will not be necessary, such as in 
classroom, meeting room, or lounge room situations where lights remain on, or where 
building external windows allow daylight into the room. 
Only in permanent installations with controlled lighting levels such as boardrooms, lecture 
theaters, or home theaters, should color management be considered. Color management 
provides fine color control adjustment to allow for more accurate color reproduction, 
should you require it.
Proper color management can only be achieved under controlled and reproducible viewing 
conditions. You will need to use a colorimeter (color light meter), and provide a set of 
suitable source images to measure color reproduction. These tools are not provided with 
the projector, however, your projector supplier should be able to provide you with suitable 
guidance, or even an experienced professional installer.
The Color Management provides six sets (RGBCMY) of colors to be adjusted. When you 
select each color, you can independently adjust its range and saturation according to your 
preference.
If you have purchased a test disc which contains various color test patterns and can be 
used to test the color presentation on monitors, TVs, projectors, etc, you can project any 
image from the disc on the screen and enter the 3D Color Management menu to make 
adjustments.
To adjust the settings:
1. Go to the PICTURE menu and highlight 3D Color Management.
2. Press MODE/ENTER on the projector or remote control and the 3D Color 
Management page appears.
3. Highlight Primary Color and press  /  to select a color from among Red, 
Yellow, Green, Cyan, Blue, or Magenta.
4. Press  to highlight Hue and press  /  to select its range. Increase in the range 
will include colors consisted of more proportions of its two adjacent colors. 
						

							Operation 30Please refer to the illustration to the right 
for how the colors relate to each other.
For example, if you select Red and set its 
range at 0, only pure red in the projected 
picture will be selected. Increasing its range 
will include red close to yellow and red close 
to magenta.
5. Press  to highlight Saturation and adjust 
its values to your preference by pressing  /
. Every adjustment made will reflect to 
the image immediately.
For example, if you select Red and set its 
value at 0, only the saturation of pure red will be affected.
Saturation is the amount of that color in a video picture. Lower settings produce less saturated colors; a 
setting of “0” removes that color from the image entirely. If the saturation is too high, that color will be 
overpowering and unrealistic.
6. Press  to highlight Gain and adjust its values to your preference by pressing  /
. The contrast level of the primary color you select will be affected. Every 
adjustment made will reflect to the image immediately. 
7. Repeat steps 3 to 6 for other color adjustments.
8. Make sure you have made all of the desired adjustments.
9. Press MENU/EXIT to exit and save the settings.
Resetting current or all picture modes
1. Go to the PICTURE menu and highlight Reset Picture Setting.
2. Press MODE/ENTER and press  /  to select Current or All.
•Current: returns current picture mode to the factory preset settings.
•All: returns all settings, except User 1/User 2 in the PICTURE menu to the 
factory preset settings.
Setting the presentation timer
Presentation timer can indicate the presentation time on the screen to help you achieve 
better time management when giving presentations. Follow these steps to utilize this 
function:
1. Go to the SYSTEM SETUP: Basic > Presentation Timer menu and press 
MODE/ENTER to display the Presentation Timer page.
2. Highlight Timer Period and decide the time period by pressing  / . The length 
of time can be set from 1 to 5 minutes in 1-minute increments and 5 to 240 minutes 
in 5-minute increments.
If the timer is already on, the timer will restart whenever the Timer Period is reset.
3. Press   to highlight Timer Display and choose if you want the timer to show up 
on the screen by press
ing /.
RED
BLUEGREEN Yellow
Cyan
Magenta
SelectionDescription
Always Displays the timer on screen throughout the presentation time.
3 min/2 min/1 min  Displays the timer on screen in the last 3/2/1 minute(s).
Never Hides the timer throughout the presentation time.