BenQ Th681 Digital Projector User Manual

							Operation 31 4. Press  to highlight Timer Position and set the timer position by pressing  /
.
5. Press   to highlight Timer Counting Direction and select your desired counting 
direction by pressing  / .
6. Press  to highlight Sound Reminder and decide if you want to activate sound 
reminder by pressing  / . If you select On, a double beep sound will be heard at 
the last 30 seconds of counting down/up, and a triple beep sound will be produced 
when the timer is up.
7. To activate the presentation timer, press   and press  /  to highlight On and 
press MODE/ENTER.
8. A confirmation message appears. Highlight Ye s and press MODE/ENTER on the 
projector or remote control to confirm. You will see the message “Timer is On” 
displaying on the screen. The timer starts counting when the timer is on.
To cancel the timer, perform the following steps:
1. Go to the SYSTEM SETUP: Basic > Presentation Timer menu and highlight 
Off. Press MODE/ENTER. A confirmation message appears.
2. Highlight Ye s and press MODE/ENTER to confirm. You will see the message 
“Timer is Off” displaying on the screen. 
Remote paging operations
Connect the projector to your PC or notebook with a USB cable prior to using the paging 
function. See Connection on page 16 for details.
You can operate your display software program (on a connected PC) which responds to 
page up/down commands (like Microsoft PowerPoint) by pressing Page Up/Page Down 
on the remote control.
If remote paging function doesnt work, check if the USB connection is correctly made and 
the mouse driver on your computer is updated to the latest version.
The remote paging function cannot work with Microsoft® Windows®98 operating system. Windows®XP or 
higher operating systems are recommended.
Freezing the image
Press Freeze on the remote control to freeze the image. The word “FREEZE” will 
display in the upper left corner of the screen. To release the function, press any key on the 
projector or remote control.
If your remote control has the following keys, please note that they cannot be pressed to release the function: 
LASER, #1, #4, Page Up/Page Down. 
Even if an image is frozen on the screen, the pictures are running on the video or other 
device. If the connected devices have active audio output, you will still hear the audio even 
though the image is frozen onscreen.
Top-Left Bottom-Left Top-Right Bottom-Right
SelectionDescription
Count Up Increases from 0 to the preset time.
Count Down Decreases from the preset time to 0. 
						

							Operation 32
Hiding the image
In order to draw the audiences full attention to the presenter, you can use ECO BLANK 
on the projector or remote control to hide the screen image. When this function is 
activated with an audio input connected, the audio can still be heard. 
You can set the blank time in the 
SYSTEM SETUP: Basic > Operation Settings > 
Blank Timer menu to let the projector return the image automatically after a period of 
time when there is no action taken on the blank screen.
If the preset time spans are not suitable for your presentation, select Disable.
No matter 
Blank Timer is activated or not, you can press most of the keys on the 
projector or remote control to restore the picture.
Do not block the projection lens from projecting as this could cause the blocking object to become heated and 
deformed or even cause a fire.
Locking control keys
With the control keys on the projector locked, you can prevent your projector settings 
from being changed accidentally (by children, for example). When the Panel Key Lock is 
on, no control keys on the projector will operate except  POWER.
1. Go to the SYSTEM SETUP: Basic > Panel Key Lock menu, and select On by 
pressing  /  on the projector or remote control. A confirmation message 
appears. 
2. Highlight Ye s and press MODE/ENTER to confirm.
To release panel key lock, use the remote control to enter the 
SYSTEM SETUP: 
Basic > 
Panel Key Lock menu and press  /  to select Off.
•  Keys on the remote control are still active when panel key lock is enabled.
•  If you turn off the projector without disabling panel key lock, the projector will still be in locked status the 
next time it is turned on.
Operating in a high altitude environment
We recommend you use the High Altitude Mode when your environment is between 
1500 m –3000 m above sea level, and ambient temperature is between 0°C–30°C.
Do not use the High Altitude Mode if your altitude is between 0 m and 1500 m and ambient temperature is 
between 0°C and 35°C. The projector will be over cooled, if you turn the mode on under such a condition.
To activate the High Altitude Mode:
1. Press MENU/EXIT and then press  /  until the SYSTEM SETUP: Advanced 
menu is highlighted.
2. Press  to highlight High Altitude Mode and press  /  select On. A 
confirmation message appears.
3. Highlight Ye s and press MODE/ENTER.
Operation under High Altitude Mode may cause a higher decibel operating noise level 
because of increased fan speed necessary to improve overall system cooling and 
performance.
If you use this projector under other extreme conditions excluding the above, it may 
display auto shut-down symptoms, which is designed to protect your projector from over-
heating. In cases like this, you should switch to High Altitude mode to solve these  
						

							Operation 33 symptoms. However, this is not to state that this projector can operate under any and all 
harsh or extreme conditions.
Adjusting the sound
The sound adjustments made as below will have an effect on the projector speaker(s). Be 
sure you have made a correct connection to the projector audio input. See Connection 
on page 16 for how the audio input is connected.
Muting the sound
To temporarily turn off the sound:
1. Press MENU/EXIT and then press  /  until the SYSTEM SETUP: Advanced 
menu is highlighted.
2. Press  to highlight Audio Settings and press MODE/ENTER. The Audio 
Settings page appears.
3. Highlight Mute and press  /  to select On.
If available, you can also press Mute on the remote control to toggle projector audio between on and off.
Adjusting the sound level
To adjust the sound level, press Volume +/- or /, or:
1. Repeat steps 1-2 above.
2. Press  to highlight Volume and press  /  to select a desired sound level.
Turning off the Power On/Off Ring Tone
To turn off the ring tone:
1. Repeat steps 1-2 above.
2. Press  to highlight Power On/Off Ring Tone and press  /  to select Off.
The only way to change Power On/Off Ring Tone is setting On or Off here. Setting the sound mute or 
changing the sound level will not affect the Power On/Off Ring Tone.
Using the test pattern
The projector is able to display the grid test 
pattern. It helps you adjust the image size and 
focus and check that the projected image is free 
from distortion.
To display the test pattern, open the OSD menu 
and go to the SYSTEM SETUP: Advanced > 
Test Pattern and press  /  to select On. 
						

							Operation 34
Using the teaching templates
The projector provides several preset patterns for various teaching purposes. To activate 
the pattern:
1. Open the OSD menu and go to the DISPLAY > Teaching Template and press 
/   to select Blackboard or Whiteboard.
2. Press /  to choose the pattern you need. 
3. Press MODE/ENTER to activate the pattern.
Teaching 
TemplateWhiteboardBlackboard
Letter 
Formation
Worksheet
Coordinate 
Chart 
						

							Operation 35
Shutting down the projector
1. Press  POWER and a confirmation message will display prompting you. 
If you dont respond in a few seconds, the message will disappear.
2. Press  POWER a second time. The POWER indicator light flashes orange, 
the projection lamp shuts down, and the fans will continue to run for approximately 
90 seconds to cool down the projector.
To protect the lamp, the projector will not respond to any commands during the cooling process.
To shorten the cooling time, you can also activate the Quick cooling function. See Quick Cooling on page 43 
for details.
3. Once the cooling process finishes, a Power Off 
Ring Tone will be heard. The POWER indicator 
light is a steady orange and fans stop. Disconnect 
the power cord from the power outlet.
•  To turn off the power ring tone, see Turning off the Power On/
Off Ring Tone on page 33 for details.
•  If the projector is not properly shut down, to protect the lamp, 
when you attempt to re-start the projector, the fans will run for a 
few minutes to cool down. Press   POWER again to start the 
projector after the fans stop and the POWER indicator light 
turns orange.
•  Lamp life results will vary depending on environmental conditions 
and usage.
Direct power off
The AC power cord can be pulled out right after the projector is turned off. To protect 
the lamp, wait about 10 minutes before re-starting the projector. (When you attempt to 
re-start the projector, the fans may run for a few minutes to cool down. In such cases, 
press  POWER again to start the projector after the fans stop and the POWER indicator 
light turns orange. 
						

							Operation 36
Menu operation
Menu system
Please note that the on-screen display (OSD) menus vary according to the signal type 
selected and the projector model you are using.
Main menu Sub-menu Options
1. 
DISPLAY
Wall ColorOff/Light Yellow/Pink/Light Green/Blue/
Blackboard
Aspect RatioAuto/Real/4:3/16:9/16:10
Keystone
Position
Phase
H. Size
Digital Zoom
3D3D ModeAuto/Top Bottom/Frame Sequential/
Frame Packing/Side by Side/Off
3D Sync InvertDisable/Invert
Apply 3D 
Settings3D Settings 1/3D Settings 2/3D Settings 
3/Off
Save 3D Settings3D Settings 1/3D Settings 2/3D Settings 
3
Teaching 
TemplateBlackboardOff/Letter Formation/Worksheet/
Coordinate Chart
WhiteboardOff/Letter Formation/Worksheet/
Coordinate Chart
2. 
PICTURE
Picture ModeDynamic/Presentation/sRGB/Cinema/(3D)/User 1/User 2
Reference ModeDynamic/Presentation/sRGB/Cinema/(3D)
Brightness
Contrast
Color
Tint
Sharpness
Brilliant ColorOn/Off
Color TemperatureCool/Normal/Warm
Color Temperature Fine TuningR Gain/G Gain/B Gain/R Offset/G 
Offset/B Offset
3D Color 
ManagementPrimary ColorR/G/B/C/M/Y
Hue
Saturation
Gain
Reset Picture SettingCurrent/All/Cancel
3. 
SOURCEQuick Auto SearchOn/Off
Color Space ConversionAuto/RGB/YUV 
						

							Operation 37
Main menu Sub-menu Options
4. 
SYSTEM 
SETUP: 
Basic
Presentation 
TimerTimer Period1~240 minutes
Timer DisplayAlways/3 min/2 min/1 min/Never
Timer PositionTop-Left/Bottom-Left/Top-Right/
Bottom-Right
Timer Counting 
DirectionCount Down/Count Up
Sound ReminderOn/Off
On/Off
Language
Projector InstallationFront Table/Rear Table/Rear 
Ceiling/Front Ceiling
Menu SettingsMenu Display 
Time5 sec/10 sec/20 sec/30 sec/Always
Menu PositionCenter/Top-Left/Top-Right/Bottom-
Right/Bottom-Left
Reminder 
MessageOn/Off
Operation 
SettingsDirect Power OnOn/Off
Signal Power OnOn/Off
Auto Power OffDisable/3 min/10 min/15 min/20 
min/25 min/30 min
Quick CoolingOn/Off
Instant RestartOn/Off
Blank TimerDisable/5 min/10 min/15 min/20 
min/25 min/30 min
Sleep TimerDisable/30 min/1 hr/2 hr/3 hr/4 hr/8 
hr/12 hr
Remote ReceiverFront+Top/Front/Top
Panel Key LockOn/Off
Background ColorBlack/Blue/Purple/BenQ
Splash ScreenBlack/Blue/BenQ 
						

							Operation 38Note that the menu items are available when the projector detects at least one valid signal. 
If there is no equipment connected to the projector or no signal detected, limited menu 
items are accessible.
Main menu Sub-menu Options
5. 
SYSTEM 
SETUP: 
Advanced
High Altitude ModeOn/Off
Audio SettingsMuteOn/Off
Volume
Power On/Off 
Ring ToneOn/Off
Lamp SettingsLamp ModeNormal/Economic/SmartEco
Reset Lamp Timer
Equivalent Lamp
Security 
SettingsChange Password
Change Security 
SettingsPower On Lock
Baud Rate2400/4800/9600/14400/19200/
38400/57600/115200
Test PatternOn/Off
Closed CaptionClosed Caption 
EnableOn/Off
Caption VersionCC1/CC2/CC3/CC4
Standby 
SettingsMonitor OutOn/Off
Audio Pass 
ThroughOff/Audio In/Audio L/R/HDMI
Reset All Settings
6. 
INFORMATIONCurrent System Status• Source
• Picture Mode
• Lamp Mode
• Resolution
• 3D Format
• Color System
• Equivalent Lamp
• Firmware Version 
						

							Operation 39
Description of each menu
Function Description
Wall ColorCorrects the projected picture’s color when the projection surface is 
not white. See Using Wall Color on page 27 for details.
Aspect RatioThere are several options to set the images aspect ratio depending on 
your input signal source. See Selecting the aspect ratio on page 25 
for details.
KeystoneCorrects any keystoning of the image. See Correcting keystone on 
page 20 for details.
Position
Displays the position adjustment page. To move the projected image, 
use the directional arrow keys. The values shown on the lower 
position of the page change with every key press you made until they 
reach their maximum or minimum.
This function is only available when a PC signal (analog RGB) is selected.
Phase
Adjusts the clock phase to reduce image 
distortion.
This function is only available when a PC signal 
(analog RGB) is selected.
H. SizeAdjusts the horizontal width of the image.
This function is only available when a PC signal (analog RGB) is selected.
Digital ZoomMagnifies or reduces the projected image. See Magnifying and 
searching for details on page 25 for details.
1. DISPLAY menu 
						

							Operation 40
Function Description
3D
This projector features a 3D function which enables you to enjoy the 
3D movies, videos, and sporting events in a more realistic way by 
presenting the depth of the images. You need to wear a pair of 3D 
glasses to view the 3D images.
3D Mode
The default setting is Auto and the projector automatically chooses 
an appropriate 3D format when detecting 3D contents. If the 
projector cannot recognize the 3D format, press  /  to choose a 
3D mode. 
When the 3D function is on:
• The brightness level of the projected image will decrease.
•  The Picture Mode cannot be adjusted.
3D Sync Invert
When you discover the inversion of the image depth, enable this 
function to correct the problem.
Apply 3D Settings
After the 3D settings are saved, you can decide if you would like to 
apply them by choosing a set of 3D settings that you have saved. Once 
applied, the projector will automatically play the incoming 3D content 
if it matches the 3D settings saved.
Only the set(s) of 3D settings with memorized data is available.
Save 3D Settings
When you have successfully displayed the 3D content after making the 
appropriate adjustments, you can enable this function and choose a set 
of 3D settings to memorize current 3D settings.
Teaching 
Template See Using the teaching templates on page 34 for details.
1. DISPLAY menu