Topway HMT028ATB-C User manual

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Name: HMT028ATB-C-Manual-Rev0.3
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HMT028ATB-C
LCD Module User Manual
Prepared by:
Gong huimei
Checked by:
Approved by:
Date: 2022-07-27
Date:
Date:
Rev.
Descriptions
Release Date
0.1
- Preliminary Draft release
2019-05-10
0.2
-Update Electrical Characteristics
2020-07-16
0.3
-Update Optical Characteristics
2022-07-27

TOPWAY
LCD Module User Manual
HMT028ATB-C
URL: www.topwaydisplay.com
Document Name: HMT028ATB-C-Manual-Rev0.3
Page: 2 of 14
Table of Content
1 Basic Specification .......................................................................................................................................3
1.1 General Specification...............................................................................................................................3
1.2 Block Diagram..........................................................................................................................................3
1.3 Terminal Function ....................................................................................................................................4
2 Absolute Maximum Ratings.........................................................................................................................5
3 Electrical Characteristics.............................................................................................................................5
3.1 DC Characteristics...................................................................................................................................5
4 Function Specifications..............................................................................................................................6
4.1 Basic Operation Function Descriptions....................................................................................................6
4.2 Quick Start Guide.....................................................................................................................................7
4.3 Command Descriptions............................................................................................................................7
5 Optical Characteristics.................................................................................................................................8
6 LCD Module Design and Handling Precautions.........................................................................................10
7 CTP Mounting Instructions...........................................................................................................................11
8 RTP Mounting Instructions...........................................................................................................................12

TOPWAY
LCD Module User Manual
HMT028ATB-C
URL: www.topwaydisplay.com
Document Name: HMT028ATB-C-Manual-Rev0.3
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1 Basic Specification
TOPWAY HMT028ATB-C is a Smart TFT Module with 32bit MCU on board. Its graphics engine provides
numbers of outstanding features. It supports preload and pre-design display interface that simplify the
host operation and development time. Suitable for industry control, instrumentation, medical electronics,
power electric equipment applications.
1.1 General Specification
Note:*1. For saturated color display content (eg. pure-red, pure-green, pure-blue, or pure-colors-combinations).
*2. For “color scales” display content.
*3. Color tone may slightly change by Temperature and Driving Condition.
*4. Seetion 1.3 for configuration.
1.2 Block Diagram
Screen Size(Diagonal) :
2.8”
Resolution :
320 x 240(RGB)
Color Depth :
65k color (16bit)
Pixel Configuration :
RGB Stripe
Display Mode :
Transmissive / Normal White
Viewing Direction :
3H (*1) (gray-scale inverse)
9H (*2)
Outline Dimension :
79.3 x 49.1 x 9.6 (max)(mm)
(see attached drawing for details)
Active Area :
57.6 x 43.2 (mm)
Backlight :
LED
Surface Treatment :
Glare Treatment
Command I/F:
UART(3.3V Logic Levels)
Project Download:
by U-Drive (with OTG cable) or by PC (*4)
Operating Temperature :
-20 ~ +70°C
Storage Temperature :
-30 ~ +80°C

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LCD Module User Manual
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Document Name: HMT028ATB-C-Manual-Rev0.3
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1.3 Terminal Function
UART Interface Terminal (K1)
Pin No.
Pin Name
I/O
Descriptions
1~5
NC
--
No connection, leave open
6,7,8
VDD
P
Power supply (5.0 V)
9
NC
--
No connection, leave open
10
RX
I
Data Input (eg. to Host MCU’s UART TXD)
11
TX
O
Data output (eg. to Host MCU’s UART RXD)
12
BUSY
O
Request To Send (function as busy BUSY signal)
1:Busy 0:No busy
(eg. to Host MCU IO, check before sending data or command>)
13,14,15
VSS
P
Ground, (0V)
16~26
NC
--
No connection, leave open
Note.
*1. User data and commands transfer through this terminal.
*2. HOST using command hand shake during communication is suggested.
UART Interface Terminal (K2)
Pin No.
Pin Name
I/O
Descriptions
1,2,3
VDD
P
Power supply (5.0 V)
4
NC
--
No connection, leave open
5
RX
I
Data Input (eg. to Host MCU’s UART TXD)
6
TX
O
Data output (eg. to Host MCU’s UART RXD)
7
BUSY
O
Request To Send (function as busy BUSY signal)
1:Busy 0:No busy
(eg. to Host MCU IO, check before sending data or command>)
8,9,10
VSS
P
Ground, (0V)
Note.
*1. User data and commands transfer through this terminal.
*2. HOST using command hand shake during communication is suggested.
USB Interface Terminal (K3)
Pin No.
Pin Name
I/O
Descriptions
1
VUSB
P
Power supply (5.0 V)
2
D-
I/O
USB DATA negative signal
3
D+
I/O
USB DATA positive signal
4
ID
I
USB_ID, 1:Client, 0:HOST
5
VSS
P
Ground, (0V)
Note.
*1. Display files preload through this terminal.
*2. Connect to U-Drive (with OTG cable), for files transfer
*3. For U-Drive to download project: R22=27R, R23=27R, R24=NC, R25=NC.(default)
For PC direct download project: R22=NC, R23=NC, R24=27R, R25=27R.

TOPWAY
LCD Module User Manual
HMT028ATB-C
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Document Name: HMT028ATB-C-Manual-Rev0.3
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2 Absolute Maximum Ratings
Items
Symbol
Min.
Max.
Unit
Condition
Power Supply voltage
Vdd
-0.3
5.5
V
Operating Temperature
TOP
-20
70
C
No Condensation
Storage Temperature
TST
-30
80
C
No Condensation
Note:
*1. This rating applies to all parts of the module and should not be exceeded.
*2. The operating temperature only guarantees operation of the circuit. The contrast, response speed,
and the other specification related to electro-optical display quality is determined at the room temperature, TOP=25℃
*3. Ambient temperature when the backlight is lit (reference value)
*4. Any Stresses exceeding the Absolute Maximum Ratings may cause substantial damage to the device. Functional
operation of this device at other conditions beyond those listed in the specification is not implied and prolonged
exposure to extreme conditions may affect device reliability.
3 Electrical Characteristics
3.1 DC Characteristics VSS=0V, VIO =3.3V, TOP =25C
Items
Symbol
MIN.
TYP.
MAX.
Unit
Applicable
Pin/FUNC
Operating Voltage
VDD
4.8
5.0
5.2
V
VDD
Rx Input Hi
VRxH
0.8VIO
-
VIO
V
Rx
Rx Input Lo
VRXL
0
-
0.2 VIO
V
Rx
Tx Output Hi
VTXH
0.7VIO
-
VIO
V
Tx
Tx Output Lo
VTXL
0
-
0.3VIO
V
Tx
Operating Current
IDD
-
190
-
mA
VDD (*1)
Note.
*1. Normal display condition

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LCD Module User Manual
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Document Name: HMT028ATB-C-Manual-Rev0.3
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4 Function Specifications
4.1 Basic Operation Function Descriptions
- Display files are stored inside FLASH memory area.
They are preloaded to HMT028ATB-C for stand alone interface use.
- Those files are preloaded via USB interface (U-Drive or PC download).
- All the interface flow and the touch response are based on the preloaded files
- VP variables memory is inside RAM area,
it provides real time access via UART by the HOST or display onto the TFT.
- Custom Memories are inside FLASH memory area
It can be accessed via UART interface by the HOST.
- Control and Draw Engine executes HOST commands and response respectively
- It also reports the real time Touch Key number to the HOST
HOST
PC
TFT Display
Custom
Memories
TML files
Picture files
ICONS files
Control and Draw Engine
Touch Panel
HMT028ATB-C
VP variables
UART
interface
USB
interface

TOPWAY
LCD Module User Manual
HMT028ATB-C
URL: www.topwaydisplay.com
Document Name: HMT028ATB-C-Manual-Rev0.3
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4.2 Quick Start Guide
1.
Install TOPWAY
Graphics Editor
2.
Import pictures
design UI flow
3.
Download to
Smart LCD
4.
power on &
display
5.
Connect to
host Show
real time
data
4.3 Command Descriptions
Please refer to “SMART LCD Command Manual ”

TOPWAY
LCD Module User Manual
HMT028ATB-C
URL: www.topwaydisplay.com
Document Name: HMT028ATB-C-Manual-Rev0.3
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5 Optical Characteristics
Item
Symbol
Condition
Min
Typ
Max
Unit
Remark
View Angles
θT
CR≧10
60
70
-
Degree
Note 3
θB
60
70
-
θL
50
60
-
θR
60
70
-
Contrast Ratio
CR
θ= 0°
400
500
-
Note 4
Response Time
TON
25℃
-
20
30
ms
Note 5
TOFF
Chromaticity
White
x
Backlight is
on
0.218
0.268
0.318
Note 1,6
y
0.234
0.284
0.334
Red
x
0.58
0.630
0.68
Note 1,6
y
0.284
0.334
0.384
Green
x
0.281
0.331
0381
Note 1,6
y
0.562
0.612
0.662
Blue
x
0.099
0.149
0.199
Note 1,6
y
0.013
0.063
0.113
Uniformity
U
75
80
-
%
Note 1,2
NTSC
60
65
-
%
Note 1,6
Luminance
L
160
200
-
cd/㎡
Note 1
Note：The parameter is slightly changed by temperature, driving voltage and materiel.

TOPWAY
LCD Module User Manual
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Document Name: HMT028ATB-C-Manual-Rev0.3
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Note 1:
The data are measured after LEDs are turned on for 5 minutes. LCM
displays full white. The brightness is the average value of 9 measured
spots. Measurement equipment PR-705 (Φ8mm)
Measuring condition:
- Measuring surroundings: Dark room
- Measuring temperature: Ta=25℃.
- Adjust operating voltage to get optimum contrast at the
center of the display.
Measured value at the center point of LCD panel after more than 5
minutes while backlight turning on.
Note 2:
The luminance uniformity is calculated by using following formula.
△Bp = Bp (Min.) / Bp (Max.)×100 (%)
Bp (Max.) = Maximum brightness in 9 measured spots
Bp (Min.) = Minimum brightness in 9 measured spots.
Note 3:
The definition of viewing angle:
Refer to the graph below marked by θ and Ф
Note 4:
The definition of contrast ratio (Test LCM using PR-705):
Contrast
Ratio(CR)=
Luminance When LCD is at “White” state
Luminance When LCD is at “Black” state
(Contrast Ratio is measured in optimum common electrode
voltage)
Note 5:
Definition of Response time. (Test LCD using DMS501):
The output signals of photo detector are measured
when the input signals are changed from
“black” to “white”(falling time)
and from “white” to “black”(rising time), respectively.
The response time is defined as
the time interval between the 10% and 90% of amplitudes.Refer to
figure as below.
Note 6:
Definition of Color of CIE Coordinate and NTSC Ratio.
Color gamut:
S=
Area of RGB triangle
X100%
Area of NTSC triangle

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6 LCD Module Design and Handling Precautions
6. 液晶显示模块设计和使用须知
-Please ensure V0, VCOM is adjustable, to enable LCD
module get the best contrast ratio under different
temperatures, view angles and positions.
-Normally display quality should be judged under the best
contrast ratio within viewable area. Unexpected display
pattern may com out under abnormal contrast ratio.
-Never operate the LCD module exceed the absolute
maximum ratings.
-Never apply signal to the LCD module without power
supply.
-Keep signal line as short as possible to reduce external
noise interference.
-IC chip (e.g. TAB or COG) is sensitive to light. Strong light
might cause malfunction. Light sealing structure casing is
recommended.
-Make sure there is enough space (with cushion) between
case and LCD panel, to prevent external force passed on
to the panel; otherwise that may cause damage to the LCD
and degrade its display result.
-Avoid showing a display pattern on screen for a long time
(continuous ON segment).
-LCD module reliability may be reduced by temperature
shock.
-When storing and operating LCD module, avoids exposure
to direct sunlight, high humidity, high or low temperature.
They may damage or degrade the LCD module.
-Never leave LCD module in extreme condition (max./min
storage/operate temperature) for more than 48hr.
-Recommend LCD module storage conditions is 0 C~40 C
<80%RH.
-LCD module should be stored in the room without acid,
alkali and harmful gas.
-Avoid dropping & violent shocking during transportation,
and no excessive pressure press, moisture and sunlight.
-LCD module can be easily damaged by static electricity.
Please maintain an optimum anti-static working
environment to protect the LCD module. (eg. ground the
soldering irons properly)
-Be sure to ground the body when handling LCD module.
-Only hold LCD module by its sides. Never hold LCD
module by applying force on the heat seal or TAB.
-When soldering, control the temperature and duration
avoid damaging the backlight guide or diffuser which
might degrade the display result such as uneven display.
-Never let LCD module contact with corrosive liquids, which
might cause damage to the backlight guide or the electric
circuit of LCD module.
-Only clean LCD with a soft dry cloth, Isopropyl Alcohol or
Ethyl Alcohol. Other solvents (e.g. water) may damage the
LCD.
-Never add force to components of LCD module. It may
cause invisible damage or degrade the module's reliability.
-When mounting LCD module, please make sure it is free
from twisting, warping and bending.
-Do not add excessive force on surface of LCD, which may
-请注意 V0, VCOM 的设定, 以确保液晶显示模块在不同的
使用温度下以及在不同的视角和位置观察模块显示，均
能达到最佳对比度，请务必将应用电路上设置为对比度
可调。
-请注意液晶显示模块的显示品质判定是指在正常对比度
下以及视窗(V.A)范围内进行的，非正常对比度下液晶可
能会出现非预期的显示不良，应注意区分。
-请勿在最大额定值以外使用液晶显示模块。
-请勿在没有接通电源的条件下，给液晶显示模块输送信
号。
-请尽可能缩短信号线的连接，以避免对液晶显示模块的
信号干扰。
-集成电路因 IC 芯片(如TAB 或COG)对紫外线极为敏感，
强光环境下可能会引起液晶显示模块功能失效，故应采
用不透光的外壳。
-
-请在液晶显示模块与外壳之间保留足够的空间(可使用衬
垫)，以缓冲外力对液晶显示模块的损坏或因受力不均而
产生的显示不匀等异常现象。
-避免液晶显示屏在某一画面下长时间点亮，否则有出现
残影的风险；请通过软件每隔一段时间改变一次画面。
-液晶显示模块的可靠性可能因温度冲击而降低。
-
-请勿在阳光直射、高湿、高温或低温下储存和使用液晶
显示模块，这将造成液晶显示模块的损坏或失效。
-请勿在极限环境(最大/最小存储/工作温度)下使用或放
置液晶显示模块超过 48 小时以上。
-液晶显示模块建议存储条件为: 0 C~40 C <80%RH。
-
-请勿让液晶显示模块存储于带有 酸性, 碱性, 有害气体
环境之中。
-在运输过程中, 请勿让液晶显示模块跌落与猛烈震动,
同时避免 异常挤压, 高湿度, 与阳光照射.
-液晶显示模块极易受静电损坏，请务必保证液晶显示模
块在防静电的工作环境中使用或保存。(如: 烙铁正确接
地,等)
-
-拿取液晶显示模块时需注意操作人员的接地情况。
-请手持液晶显示模块的边沿取放模块，防止热压纸或 TAB
部位受力。
-焊接液晶模块时，请注意控制烙铁的温度、焊接时间，
以免烫坏导光板或偏光片，导致显示不匀等不良现象发
生。
-请勿使用洗板水等腐蚀性液体接触液晶模块，以免腐蚀
导光板或模块电路。
-仅可使用柔软的干布, 异丙醇或乙醇清洁液晶屏表面，
其他任何溶剂(如:水)都有可能损坏液晶模块。
-
-请勿挤压液晶显示模块上的元器件，以避免产生潜在的
损坏或失效而影响产品可靠性。
-装配液晶显示模块时，请务必注意避免液晶显示模块的
扭曲或变形。
-请勿挤压液晶显示屏表面，这将导致显示颜色的异常。

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cause the display color change abnormally.
-LCD panel is made with glass. Any mechanical shock (e.g.
dropping from high place) will damage the LCD module.
-
-液晶屏由玻璃制作而成，任何机械碰撞(如从高处跌落)
均有可能损坏液晶显示模块。
-Protective film is attached on LCD screen. Be careful when
peeling off this protective film, since static electricity may
be generated.
-Polarizer on LCD gets scratched easily. If possible, do not
remove LCD protective film until the last step of
installation.
-When peeling off protective film from LCD, static charge
may cause abnormal display pattern. The symptom is
normal, and it will turn back to normal in a short while.
-LCD panel has sharp edges, please handle with care.
-Never attempt to disassemble or rework LCD module.
-If display panel is damaged and liquid crystal substance
leaks out, be sure not to get any in your mouth, if the
substance comes into contact with your skin or clothes
promptly wash it off using soap and water.
7 CTP Mounting Instructions
7.1 Bezel Mounting (Figure 1)
-The bezel window should be bigger than the CTP active
area. It should be≥0.5mm each side.
-Gasket should be installed between the bezel and the CTP
surface.
The final gap should be about 0.5~1.0mm.
-It is recommended to provide an additional support
bracket for backside support when necessary (e.g. slim
type TFT module without mounding structure). They
should only provide appropriate support and keep the
module in place.
-The mounting structure should be strong enough to
prevent external uneven force or twist act onto the
module.
-液晶屏表面带有保护膜, 揭除保护膜时需要注意可能产
生的静电。
-
-因液晶显示屏表面的偏光片极易划伤，安装完成之前请
尽量不要揭下保护膜。
-
-请缓慢揭除保护膜，在此过程中液晶显示屏上可能会产
生静电线，此为正常情况，可在短时间内消失。
-
-请注意避免被液晶显示屏的边缘割伤。
-请不要试图拆卸或改造液晶显示模块。
-当液晶显示屏出现破裂, 内部液晶液体可能流出; 相关
液体不可吞吃, 绝对不可接触嘴巴, 如接触到皮肤或衣
服, 请使用肥皂与清水彻底清洗.
-
7. 电容触摸屏安装指导
7.1 面框安装（附图 1）
-客户面框窗口应大于 CTP 动作区域，各边离动作区应
≥0.5mm.
-面框与 CTP 面板间应垫有胶垫，其最终间隙约为 0.5～
1.0mm.
-
-建议必要时在背面提供附加支架(例如无安装结构的薄型
TFT 模块)，应仅利用适当支撑以保持模块位置.
-安装结构应具有足够的强度，以防止外部不均匀力或扭
曲力作用到模块上.
Figure 1
7.2 Surface Mounting (Figure 2)
-As the CTP assembling on the countersink area with
double side adhesive.
The countersink area should be flat and clean to ensure
the double side adhesive installation result.
-The Bezel is recommend to keep a gap (≥0.3mm each
side) around the cover lens for tolerance.
-It is recommended to provide an additional support
bracket with gasket for backside support when necessary
(e.g. TFT module without mounding structure). They
should only provide appropriate support and keep the
module in place.
-The mounting structure should be strong enough to
prevent external uneven force or twist act onto the module
7.2 嵌入安装（附图 2）
-客户面框应具有使用双面胶粘贴 CTP 的结构沉台面，其
粘贴面要求平整且洁净无污以保证粘贴牢靠.
-考虑到制作误差，建议面框与 CTP 盖板之间四周留有
≥0.3mm 间隙.
-建议必要时在背面提供垫有胶垫附加支架(例如无安装结
构的 TFT 模块)，应仅利用适当支撑以保持模块位置.
-安装结构应具有足够的强度，以防止外部不均匀力或扭
曲力作用到模块上。

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Name: HMT028ATB-C-Manual-Rev0.3
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Figure 2
7.3 Additional Cover Lens Mounting (Figure 3)
-For the case of additional cover Lens mounting, it is
necessary to recheck with the CTP specification about the
material and thickness to ensure the functionality.
-It should keep a 0.2~0.3mm gap between the cover lens
and the CTP surface..
-The cover lens window should be bigger than the active
area of the CTP.It should be≥0.5mm each side.
-It is recommended to provide an additional support
bracket for backside support when necessary (e.g. slim
type TFT module without mounding structure). They
should only provide appropriate support and keep the
module in place.
-The mounting structure should be strong enough to
prevent external uneven force or twist act onto the
module.
7.3 覆加盖板（附图 3）
-需要覆加玻璃盖板的安装，为确保其功能，有必要查看
产品规格书中有关盖板材料和厚度的说明.
-玻璃盖板与 CTP 表面之间应留有 0.2～0.3mm 间隙.
-玻璃盖板视窗应大于 CTP 动作区域，各边离动作区应
≥0.5mm。
-建议必要时在背面提供附加支架(例如无安装结构的薄型
TFT 模块)，应仅利用适当支撑以保持模块位置.
-安装结构应具有足够的强度，以防止外部不均匀力或扭
曲力作用到模块上.
Figure 3
8 RTP Mounting Instructions
-It should bezel touching the RTP Active Area (A.A.) to
prevent abnormal touch.It should left gab D=0.2~0.3mm
in between. (Figure 4)
8. 电阻触摸屏安装指导
-为避免面框直接压在动作区(A.A.)上造成误动作，面框与
电阻触摸屏(RTP)之间应留有一定的空隙 D=0.2~0.3mm 之
间.(附图 4)
-Outer bezel design should take care about the area
outside the A.A. Those areas contain circuit wires which is
having different thickness. Touching those areas could de-
form the ITO film. As a result bezel the ITO film be
damaged and shorten its lifetime.
It is suggested to protect those areas with gasket (between
the bezel and RTP).The suggested figures are B≥0.50mm;
C≥0.50mm. (Figure 4)
-设计面框时，要注意用面框保护触摸屏四周的非保证操作
区域，因为布线区域在此处形成一台阶，在此区域附近
操作时 ITO Film 变形较大，容易导致 ITO 损坏而降低寿
命。为保护 RTP 和避免误操作，在 RTP 与面框之间垫缓
冲物（Gasket），我们建议设计面框应覆盖动作区的边
缘，面框边缘到 V.A.区的距离 B≥0.50mm; 垫圈内边缘
到V.A.区的距离 C≥0.50mm. (附图 4)
-The bezel side wall should keep space E= 0.2 ~ 0.3mm
from the RTP. (Figure 4)
-在设计面框与 RTP 组装时，应考虑到面框内侧与 RTP 外侧
的间距 E≥0.2mm. (附图 4)

URL: www.topwaydisplay.com Document
Name: HMT028ATB-C-Manual-Rev0.3
Page: 13 of 14
Figure 4
-In general design,
RTP V.A. should be bigger than the TFT V.A.
and RTP A.A. should be bigger than the TFT A.A.
(Figure 5)
-通常设计时：
RTP 的可视区 V.A. 应不小于 TFT 的可视区 V.A.
及RTP 的动作区 A.A. 应不小于 TFT 的动作区 A.A.
(附图 5)
Figure 5
Warranty
This product has been manufactured to our company’s specifications as a part for use in your company’s general
electronic products. It is guaranteed to perform according to delivery specifications. For any other use apart from
general electronic equipment, we cannot take responsibility if the product is used in medical devices, nuclear power
control equipment, aerospace equipment, fire and security systems, or any other applications in which there is a direct
risk to human life and where extremely high levels of reliability are required. If the product is to be used in any of the
above applications, we will need to enter into a separate product liability agreement.
-We cannot accept responsibility for any defect, which may arise form additional manufacturing of the product
(including disassembly and reassembly), after product delivery.
-We cannot accept responsibility for any defect, which may arise after the application of strong external force to the
product.
-We cannot accept responsibility for any defect, which may arise due to the application of static electricity after the
product has passed our company’s acceptance inspection procedures.
-When the product is in CCFL models, CCFL service life and brightness will vary according to the performance of the
inverter used, leaks, etc. We cannot accept responsibility for product performance, reliability, or defect, which may
arise.
We cannot accept responsibility for intellectual property of a third part, which may arise through the application of our
product to our assembly with exception to those issues relating directly to the structure or method of manufacturing of our
product.