Sony DTV-01 User manual

S®
Training Manual
Circuit Description and Troubleshooting
Course: DTV-01
High Definition
Television

Introduction 1
HDTV Transmission Stream 3
Introduction to MPEG-2 Compression 9
Model KW-34HD1 - Normal Operation 19
Inputs 21
Overall Block 25
SIGNAL PROCESS
Video Block 1 29
Video Process A 31
Video Process B 33
Video Block 2 35
Digital Realty Creation 37
MID - Multi Image Driver 41
Table of Contents
Video Process C 43
Video Block 3 45
Video Process D 47
On Screen Display 49
Video Process E 51
Screen Voltage Control 53
POWER SUPPLY
Power Supply Block 55
Standby Power 53
Converter 2 61
Overall Protection Block 67
D Board Protection Block 71
Protection Circuit 1 73
Protection Circuit 2 75
Protection Circuit 3 77
Protection Circuit 4 81
DEFLECTION
Vertical Deflection 85
Horizontal Deflection Block 89
Horizontal Drive 91
Horizontal Driver 93
Horizontal Output PWM 1 97
Horizontal Output PWM 2 101
Pincushion Correction 105
Picture Tilt Circuit 109
Dynamic Focus Block 113

Dynamic Focus 1 - B+ Mfg. 117
Dynamic Focus 2 - Location 121
Dynamic Quadrapole Focus 125
Appendix
Set-Back Box i
Picture Size Modes iii
BoardReplacement iv
Service Mode Display vi

1
Introduction
TV Transmission Formats
Standard Definition/High Definition
Picture resolution is commonly measured in pixels or lines. The number
of pixels is the number of black to white brightness changes possible on
the screen first in a horizontal, then in a vertical row (e.g. 960x480). CRT
manufacturing tolerances limits the number of pixels possible. This is a
common resolution specification in a computer monitor CRT.
In a TV broadcast, the studio camera is the limitation to higher resolution.
The picture scanned by the camera is segmented by pixels similar to the
viewer’s CRT. The greater the number of pixels in the horizontal and ver-
tical row, the greater the resolution. This will be the current resolution
limitationastheUSA makesthe transitiontoward highdefinition digitalTV.
In a TV transmission, the ability of a signal voltage to quickly change from
low to high and to produce a dark to white transition is comparable to a
pixel. This is not a limitation in the transmission format, but the number of
lines transmitted is and is used as a resolution measurement in transmis-
sions. Thenumber of lines transmitted in the current USANTSC format is
525. This is considered a standard definition (SD) transmission.
A standard definition (SD) transmission of 525 lines can be transmitted in
the analog or digital mode. A higher definition (HD) transmission can be
transmitted only in the digital (DTV) mode.
¨SDTV or SD – Standard definition is the current 525 lines of resolution
transmitted, but only 480 of those lines are viewable. SD can be sent
as an NTSC analog or digital (DTV) transmission.
¨HDTV or HD – A high-definition transmission contains 720 or more
horizontal lines. HD is transmitted only in a digital format.
¨DTV – A digital TV transmission refers only to the digital encoding of
thepicture signal that may containeither a high (HD) orlow (SD) reso-
lutionpicture. The digitalpicture is not viewable on an analogTV with-
out a “decoder box”.
Digital Transmission Formats
There are 18 approved digital transmission formats. The first six offer HD
signals in a 16x9 aspect ratio. The remaining 12 formats are SD signals
inprogressive (p) or interlaced (i) scan. Although not highresolution, they
offer significant improvements over the NTSC analog signal.
18 Digital Transmission Formats
Resolution Aspect
Ratio Frames Resolution Aspect Ratio Frames
1. 1920x1080 16:9 30 i 10. 704x 480 16:9 24 p
2. “ 16:9 30 p 11. “ 4:3 60 p
3. “ 16:9 24 p 12. “ 4:3 30 i
4. 1280x 720 16:9 60 p 13. “ 4:3 30 p
5. “ 16:9 30 p 14. “ 4:3 24 p
6. “ 16:9 24 p 15. 640x 480 4:3 60 p
7. 704x 480 16:9 60 p 16. “ 4:3 30 i
8. “ 16:9 30 i 17. “ 4:3 30 p
9. “ 16:9 30 p 18. “ 4:3 24 p
A standard definition transmission permits space for another digital video
stream to coexist on the same frequency (channel). Consequently a sta-
tion can have more than one program stream on a digital channel. The
maximum number is not known at this time.

2
How to use this book for servicing
When encountering this TV set for servicing there are several things you
need to know. Below is a list of the necessary servicing items and where
to locate them: Servicing Needs
Information Location
1. Hookup / Operation / Normal
Operation First document in this training manual (Normal Operation)
2. External HDTV set-back box
indicator lights Appendix
3. Location of power handling parts
and fuses Service manual / visual inspection of heat sinks
4. Standby light indication message &
board determination Service manual and Protection Block document
5. Shutdown troubleshooting plan Protect Circuitry 3 & 4
6. Power Supply, Deflection, Video
Selection and Signal Flow Circuitry Circuitry in this training book.
See table of contents.
7. Focus Circuitry Circuitry in this training book
8. Dynamic Convergence adjustments Service manual page 27
(same as in training manual
supplement)
9. Adjustments after tube replacement Notes on using the service
mode follow this chart.
A list of register names are in
the service manual.
Training manual supplement
Service Mode Adjustment Notes
Becauseof this TV’scomplexity, the following precautions shouldbe noted
while making service adjustments for convergence, video level, size, and
white balance or positioning:
1. The numerous service mode registers are usually grouped by ICs for
easyaccess. Use the remote’s #2 and#5 button to change ICgroups.
Then you can move from register to register with the #1 and #4 but-
tons.
2. Each register that controls the picture’s size, deflection and position
(on pages 45-47 of the service manual) has seven sets of adjustment
data, one for each of the seven picture size modes. These settings do
not interact. Enter the service mode, adjust the TV during that picture
size, and store it.
Seven Picture Size Modes
NTSC or SD DTV HDTV
1. Normal 4:3
aspect ratio 4. Wide Zoom 6. HDTV Full
2. Full 16:9 aspect
ratio
3. Zoom
5. Caption
(Top & bottom pix
compressed)
7. HDTV Twin View
1. Some registers are duplicated under different groups for ease of ad-
justments. These duplicated registers have the same name. Chang-
ing the register data at one location causes the data to change at the
other location as well.
2. Save adjustments often. Changing registers will hold the new data,
but changing picture sizes (zoom, full, caption, etc) will instantly lose
any unsaved data that was just held.
3. There are separate contrast, color level, and hue adjustments for:
¨The main picture
¨The HDTV picture
¨Each twin view picture
They are adjusted for equal levels as you switch modes. This is so
the picture is not brighter in one mode than another.

9
Introduction to MPEG-2 Compression
MPEG stands for Motion Picture Experts Group, named after the com-
mittee that developed the standard.
Why Compress?
MPEG defines a compression scheme for Video which evolved from the
need to transmit digital video on existing communication channels with
limited bandwidth. In addition to the bandwidth issue there is an obvious
storage one as well.
Fastest Communication Channels Typical Bandwidth
ISDN Line 144Kbps
T1 Line 1.5 Mbps
T3 Line 45 Mbps
With a whopping 4.7 gigabytes of data capacity, DVD-Video would seem
to have more than enough room for motion pictures. Unfortunately, digital
video has an incredibly voracious appetite for storage.
Raw or uncompressed Digital Video requires an enormous 252 Mega-
bits/sec of bandwidth and approx 31 Mbytes per second of storage.
720x480 (Res.) X 8bits/sample X 30frames/sec X 3 Components
To understand this figure, we need to understand video in its purest form.
Component Video
In its purest form, Video is made up of 4 components.
- Luminance or Y which defines the brightness level and
- Color which is made up of 3 components called R-Y, B-Y and G-Y.
As it works out, we can mathematically calculate the 4th component (G-
Y) from the others. Therefore, we only require 3 components for Video
(Y, R-Y and B-Y). Y = (R-Y) + (B-Y) + (G-Y)
Each sample we take of the video is represented by an 8 bit digital word
which translates to 28or 256 different levels of each component. There-
fore, each pixel is made up of 3 components which can represent up to
28 (Y) X 28 (R-Y) X 28 (B-Y) = 224 (commonly known as 24 bit color)or 16
million colors.
R-YB-YY
One PIXEL
The resolution or picture detail we require also plays an important role in
our bandwidth and storage requirement. DVD uses a 720 Horizontal by
480 Vertical resolution or 720 pixels across times 480 rows or lines.
720
480
In summary we need to:
- sample 3 components (Y, R-Y and B-Y) each of which is composed
of 720 x 480 (350,000) pixels.
- Represent each one by an 8 bit word (3 X 350,000 X 8 =
8,400,000bits). Therefore, each frame is made up of 8,400,000
bits.
- Finally, we would need to display at 30 frames per second (30 X
8,400,000 =252,000,000 bits/sec or 252 Mbits/sec Bandwidth.
To calculate the storage we simply divide the Bandwidth in bits by 8 bits
per byte and we get 31.5Mbytes/sec Storage requirement.
As illustrated, the requirement is enormous which paves the way for com-
pression and MPEG.

10
Compression Process
Compression of Video is accomplished via the following process.
1. Selective Sampling
2. Discrete Cosine Transform (DCT)
3. Predictive & Motion Encoding
4. Hoffman Encoding
Selective Sampling
The number of times per second that you sample a signal is called its
sampling frequency. In Audio, the sampling frequency is 44,000 samples/
sec which is approx 2 times the highest frequency in Audio (20,000 Hz).
In contrast, Video is sampled at 4 times the highest frequency (13.5Mhz).
Hence the term 4 in the sampling structure 4:4:4 representing the sam-
pling ratio of Y, R-Y and B-Y respectively.
Therefore, the same number of samples are taken of Y as they are of R-
Y and B-Y.
Time
Signal
4:2:2
Since the eye is less perceptive to color changes than to Luminance,
significant reduction of data can be accomplished in the Sampling
process if we sample the color components (R-Y and B-Y) half as
much as the Luminance component (Y). The result is a 1/3 reduction
or a bandwidth of 166Mbits/sec.
Video sampled using this technique is represented by a 4:2:2 sampling
structure.Y is sampled normally withR-Y andB-Y sampled half as much.
LINE 1
LINE 2
.
.
.
.
LINE 480
ONE
PIXEL Samples taken in the Horizontal direction up to 720 per Line
Non Sampled components Illustrated as clear boxes
R-Y B-YY YR-Y B-YYY
R-Y B-YY YR-Y B-YYY
4:1:1
Consequently techniques such as the 4:1:1 further reduce color sam-
pling to 1/4th of the Y component and compress by ½ or reduce band-
width to 125Mbits/sec.

11
4:2:0
DVD takes it to another level by using a modified 4:2:2 sampling struc-
ture called 4:2:0. 4:2:0 samples R-Y half as much as Y and skips B-Y
on the 1st line. However, on the next horizontal line, B-Y is sampled half
as much as Y and R-Y is skipped. This routine is repeated effectively
reducing the color components by another half achieving ½ compres-
sion or a 125Mbit/sec bandwidth.
Through interpolation, the 4:2:0 is reconstructed into 4:2:2 without the
extra bandwidth requirement.
YB-YY
R-YYYR-YY
Y B-Y Y
LINE 1
LINE 2
LINE 3
LINE 4
.
.
.
.
LINE 480
ONE
PIXEL Samples taken in the Horizontal direction up to 720 per Line
R-YY YR-YYY
B-YY Y
Non Sampled components Illustrated as clear boxes
Y
YB-YY
Discrete Cosine Transform
After the Selective Sampling process is complete, the next step in the
MPEG process is to remove very fine picture detail imperceptible to the
human eye. It is imperceptible because it is typically masked by other
picture content.
In a Video Frame, the very fine picture details consist of high frequency
information which are basically fast changing Luminance and Color
content. In contrast, low frequency information are slow changing
Luminance and Color content.
The high frequency information consumes the most data real estate and
is where we focus to compress in this next stage.
The process of eliminating the imperceptible information is called Dis-
crete Cosine Transform or DCT. The sampling process converts the
information into digital data as described previously. Each digital picture
frame is then sectioned off into 5400 blocks each consisting of 8 pixels
wide X 8 pixels high.
8 X 8
Pixel
Block
Picture
Frame
1 of 5400
Blocks
DCT transforms the 8X8 group of pixel values into frequency compo-
nents.
Although pixel values vary randomly in the 8X8 block, DCT re-positions
low frequency components on the upper left corner and high frequency
components on the lower right of the block.
Through an additional numerical conversion process called “Quantiza-
tion”, frequency component values are assigned.
High freq components are identified by the zero values (lower right) and
low freq components by the larger values (upper left).

12
Data compression is accomplished by elimination of the high frequency
components designated by the zeros.
105100000
5000000
00000000
0
00000000
00000000
00000000
00000000
00000000
8 X 8 Pixel Block
LFreq HFref
HFref
Spacial Redundancy
Within a Frame, there are many redundant pixels. An example would
be a blue sky. This type of redundancy within the Horizotal and Vertical
plane of a frame is called “Spacial Redundancy”.
One pixel could be stored with information to repeat for the remaining
pixels. This would eliminate the need to store every pixel in the frame.
Frames making use of this technique are called “Intra-Frames”.
Temporal Redundancy
Within Video scenes, there are many redundant frames. An example
would be an anchor person reporting the news. With the exception of
lip movement, the other portions of the frame remain unchanged over
time. This type of redundancy over time is called “Temporal Redun-
dancy”.
The first frame could be stored as the reference or non changing por-
tions while remaining frames carry the lip motion information. This would
eliminate the need to store several full frames.
Frames using Temporal redundancy which predict information based on
preceding frames are called “Inter-Frames” or Motion predicted Images.
Predictive & Motion Encoding
The next step in the MPEG process is termed “Predictive & Motion
Encoding” and it takes advantage of both Spacial and Temporal redun-
dancy to achieve compression.
I-Pictures
To begin the process of using Spacial and Temporal redundancy tech-
niques in compression, we need a reference or a start frame which does
not depend on previous or preceding frames.
This start frame would make use of Spacial redundancy within itself and
is termed an I picture.
I pictures are Intra-Frames and have zero dependency on previous or
preceding frames. They do however provide information to preceding
frames.
The other pictures types used by MPEG are called P-Pictures (Predic-
tive) and B-Pictures (Bi-Directional).
I Pictures carry the most amount of data content. They are 3 times the
size of a P-Picture and 5 to 6 times the size of a B-Picture.

13
P-Pictures
The P-Pictures are Predictive Encoded Images also known as Inter-
Frames.
As the name indicates, a P-Picture is a predicted Image based on
previous I or P-Picture. The P-Picture is dependent on past Images to
exist.
I or P
Picture
P-Picture
Predicted
by looking
back at
previous
I or P Pic
Information
passed to
generate
P Picture
B-Pictures
The B-Pictures have Bi-directional dependency and are called Bi-
Directional Predicted Images.
The B-Picture is also a predicted Image but it is based on prior I or P
Pictures and preceding P-Pictures.
B-Pictures are typically made up of motion information and carry the
least amount of data.
I or P
Picture B-Pictures
Predicted
by looking
back at
previous
I or P Pic
And
Future
P Picture
P Picture