Technical Report PPD Standard layout Technical Report

SELECTIVE SCREEN HEATING

EXCEL SOFTWARE TOOL

2001-06-14

TVR-253-01-ID/D053

PPD-TMA

Philips ComponentsAbstract

Report no:TVR-253-01-ID/D053Date: 2001-06-14

Title:SELECTIVE SCREEN HEATING

Keywords:selective heating, IR, Quartz, flowcoat, tool

Author(s):Ivo Durlinger

Place a summary of the reports after this heading. Keep in mind that the summary is meant to enable someone to decide whether the report is of interest to him or her. Include purpose, intended audience, scope and conclusions. If there are many or long conclusions, dont include them all, but just the main points or state that they can be found in the report.

Summary and Conclusions:

Selective screen heating is used in the flowcoat/lacquering lines to ensure a well-controlled screen temperature. Until now the design of selective heating equipment has been done by the author in the PPD-SPG group. He used a series of software programs written in Turbo-Pascal language. The programs, intended for personal use, are neither well-documented nor easily transferable.

In order to facilitate the transfer of the know-how of selective screen heater design, the author developed a (user-friendly) Excel software tool that incorporates all the features of the different Pascal-based programs.

This report describes the (theoretical) backgrounds of the used algorithms and a step-by-step tutorial to guide the user through the tool. Input for the model: radiator positions in the selective heater, irradiation distribution of a single radiator, heating time per radiator, glass contour description, matrix transmission distribution description, physical glass properties (conductivity, density, specific heat, absorption), line speed, number of heating positions, required temperature increase, heat transfer coefficients to ambient, initial glass temperature, ambient temperature. Output of the model: footprint of heater, irradiation distribution at screen surface, heating rate distribution, time plot of screen temperature (centre, corner) during heating and equalising, time plot of temperature gradient in glass (corner) during heating and equalising.

The hardware of the software tool (CD-R) will be supplied to PTE/PPD-SPG/LDC-Dapon.

Number of pages of complete report: 31Place a list of copyholders of the Abstract between the Copylist abstract heading and the Copylist complete report (including abstract) heading:.

Copylist abstract:Guus van Acker, Peter Franken, Henk van Haren, Ad Leenaars, Maurits Smits, Godfried Tosseram

Copylist complete report (including abstract):

PPD: Marc Busio, Christ Flinsenberg, Michiel van de Water, Chris Selten, Tom Vrancken

PTE: Johnny Eijmberts, Sef Lamers

LDC: C.C. Chen, Jekyll Chen, Friederike Picht

TABLE OF CONTENTS11Introduction

1.1Overview12BaSICS oF SeLective Screen Heating22.1Design rules for lamp/reflector distances.22.1.1Lamp/reflector irradiation profile required distance to screen22.1.2Lamp arrangement in selective heating unit.52.1.3Design rules52.2Irradiation profile of lamp/reflector combination.62.3Irradiation distribution of the selective heating unit.72.3.1Division of lamps in electrical groups.72.3.2Irradiation distribution at the screen surface.72.4Heat transfer efficiency.82.4.1Short wave IR absorption data.92.4.2Matrix transmission and glass thickness data.92.4.3Estimate of the heat transfer efficiency.102.5Number of selective heating units (estimate)112.6Equalising122.6.1Numerical calculation of heating/equalising.133Using the Excel-tool143.1General information143.2Tutorial getting used to the tool153.3Further reading273.4Advanced options273.4.1Lamp axis parallel to short screen side273.4.2The use of a different radiator.273.4.3Changing physical constants of the glass283.4.4Changing heat exchange to ambient.28References28

1 Introduction

Selective screen heating is used in the front-end screen processing area to ensure a well-defined screen temperature at the critical process positions. Screen temperature is an important process parameter influencing the thickness (distribution) and drying behaviour of the applied wet layers (photo resist, phosphor suspension, prewet, lacquer).

Selective screen heating is selective in two ways: from screen to screen and within the screen. Screen-to-screen temperature differences arise if screens are loaded from different sources (e.g. buffers, rewash lines). To reduce these screen-to-screen variations, the current selective heating equipment uses a feed-forward control system. The measured screen temperature (outside centre) before selective heating determines the selective heating time.

The temperature distribution of a screen can be influenced by applying different heating times to the radiators in the selective heating units. With the current control software this distribution is not adjustable from screen to screen.

After screen heating sufficient equalising time is needed to reduce temperature gradients in the glass.

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1.1 Overview

Chapter 2 gives some (theoretical) backgrounds of the heating of glass with IR-Quartz lamps. This background is needed if the user wants to understand the algorithms in the Excel tool.

Chapter 3 explains the structure of the Excel tool that is developed for selective screen heating equipment design. A tutorial is added to guide the user through the tool, giving a default selective screen heater design procedure. The chapter concludes with a reference list of reports on selective screen heating designs by the author.

The next paragraph describes the non-standard notations that are used in this report. It is mandatory for all reports. If there are no non-standard notations state: No non-standard notations2 BaSICS oF SeLective Screen Heating

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2.1 Design rules for lamp/reflector distances.

The design rule for the vertical distance of a lamp reflector combination to a screen follows from the requirement with respect to irradiation uniformity.

Design rules for horizontal distances between lamp/reflector combinations in a selective heating unit follow from the requirements with respect to irradiation uniformity and from geometrical limitations.

2.1.1 Lamp/reflector irradiation profile required distance to screen

In selective screen heating tubular Quartz IR lamps are used (Philips type 13169 Z/98, 12NC code 9238 527 44500) in an aluminium parabolic reflector (Philips type IR6, drawing 7322 308 4078).

The parabolic reflector and the lamp holders (Philips type 6707, 12NC code 9145 100 00500) are mounted directly to the base plate: the lamp is not in the focal point of the reflector.

Sketch 1.

The irradiation distribution of the lamp-reflector combination is dependent on the distance to the irradiated surface. This distribution can be decomposed in a length wise distribution (parallel to the lamp axis) and a cross-wise distribution (perpendicular to the lamp axis). See sketch 2.

Sketch 2.

For this lamp-reflector combination, the irradiance distribution was measured at different vertical distances (defined as distance of lowest point of reflector to surface) at the Central Development Department of Lighting in Eindhoven. See graph 1 and 2.

Graph 1.

Graph 2.

If lamps are mounted in a two-dimensional array then the distances between the lamps should be :

smaller than the 50% irradiance widths of the individual lamps to avoid dips in the irradiance distribution

larger than the dimensions of the reflector (163 * 86 mm), which is a geometrical limitation.

The 50% irradiance width of the cross wise distribution at vertical distance of 5 cm is 7.2 cm (=2 x 3.6 cm), which is smaller than the reflector width (8.6 cm). Every two-dimensional arrangement of lamps positioned at 5 cm distance from a surface will show dips in the irradiance distribution!

At 10 cm vertical distance the 50% irradiance width of the length- and cross wise distribution respectively is 20 (=2 x 10) and 15 (=2 x 7.5) cm, which is larger than the reflector dimensions. For all selective heating designs the minimum vertical distance of reflector to screen is specified to be 10 cm and dips in the irradiance distribution can be avoided if the spacing between the lamps is smaller than 20 cm (length-wise) and 15 cm (cross-wise).

Vertical distances larger than 10 cm will result in lower irradiances (energy loss) and loss of selectivity (too much overlap of individual lamp irradiance profiles).

Design rule 1 (to avoid dips in irradiation pattern):

distance lowest point reflector to highest point of irradiated surface: 10 cm

lamp pitch in direction parallel to lamp axis ( 20 cm

lamp pitch in direction perpendicular to lamp axis between ( 15 cm

2.1.2 Lamp arrangement in selective heating unit.

In order to minimise the number of selective heating units, the number of lamps per unit area should be maximised. The geometrical dimensions of the lamp are larger than the reflector dimensions (lamp holder). The best packing density is obtained if the lamp holders are positioned between the reflectors of adjacent lamps (see figure 1). In this way a two-dimensional array of lamps can be designed with lamp pitches of ( 17 and ( 6 cm respectively parallel and perpendicular to the lamp axis.

Figure 1. Close packing of lamp-reflector in heating unit.

Design rule 2 (geometrical limitation):

lamp pitch in direction parallel to lamp axis ( 17 cm

lamp pitch in direction perpendicular to lamp axis between ( 12 cm

In designs the lamps are positioned default with the lamp axis parallel to the long screen axis.

The optimal lamp pitches are dependent on the screen type (or screen type mix) and the maximum available space for the selective heating unit. The latter is dependent on the belt width (or belt pitch perpendicular to screen transport direction in case of double track) and belt pitch in the transport direction. Design of selective heating units for new lines should preferably start before the dimensions of the screen heating belt are fixed.

2.1.3 Design rules

Combining design rules 1 and 2 gives:

distance lowest point reflector to highest point of irradiated surface: 10 cm

lamp pitch in direction parallel to lamp axis between 17 and 20 cm

lamp pitch in direction perpendicular to lamp axis between 12 and 15 cm

2.2 Irradiation profile of lamp/reflector combination.

The two-dimensional irradiation profile of a lamp reflector combination can be calculated using formula {1}, with the lamp-axis parallel to the x-axis and the lamp centre at (0,0):

I(x,y) = Ilw(x).Icw(y)/ Icentre

{1}

I(x,y) : irradiance at (x,y)

Ilw(x)

: irradiance parallel to lamp axis (length-wise) at (x,0)

Icw(y)

: irradiance perpendicular to lamp axis (cross-wise) at (0,y)

Icentre

: irradiance at centre (0,0)

Ilw(x) and Icw(y) , with lamp-reflector combination positioned at 10 cm vertical distance to a plane, are given in table 1.

x,y

[cm]Ilw(x)

[kW/m2]Icw(y)

[kW/m2]

08.698.69

18.638.55

28.428.28

38.287.93

47.877.18

57.466.62

66.975.73

76.424.76

85.793.86

95.113.17

104.482.55

113.722.14

123.251.86

132.691.59

142.211.37

151.861.17

161.591.10

171.310.96

181.040.82

190.890.76

200.770.69

210.640.62

220.560.55

230.440.48

240.320.41

250.220.34

260.120.27

270.060.20

280.000.13

290.000.06

300.000.00

Table 1. Irradiation distribution on surface at vertical distance 10 cm

2.3 Irradiation distribution of the selective heating unit.

2.3.1 Division of lamps in electrical groups.

The irradiation distribution of a selective heating unit at the (flat) screen surface in theory can be flat if the selective heating unit is much larger than the screen dimensions. In practice the space for the selective heating unit is limited (restrictions to floor space) and as a consequence the irradiation at the screen edges is lower than in the centre. To compensate this the heating times applied to the outer lamps can be set longer than the times applied to the inner lamps. Therefor the lamps should be divided in electrical groups. The number of groups always is a balance between costs and flexibility (different screen types).

Note that heating time control is cheaper than power control and that power control does not give any benefits. Using power control to increase the irradiance by increasing the voltage above the nominal will strongly deteriorate the of the lamp life.

2.3.2 Irradiation distribution at the screen surface.

The effective irradiation distribution at the screen surface can be calculated using the irradiation distribution of a single lamp reflector combination (formula {1}), the lamp positions in the selective heating unit and the relative heating times applied to the lamps:

I(x,y) = (i ((i).Ilw(abs(x-x(i))).Icw(abs(y-y(i))) / Icentre

{2}

((i)

: relative heating time of lamp i

[-]

x(i)

: x-position of lamp i

[cm]

y(i)

: y-position of lamp i

[cm]

In principle this calculation is only correct for real flat screens (no outside curvature) but for selective heating design purposes it can be used for flat square/ super flat types as well. The irradiance to the corners in that case is (slightly) overestimated.

2.4 Heat transfer efficiency.

The spectral energy distribution of the lamp approximates the distribution of a black body radiator with (max=1.2 (m. At this short wavelength screen glass is not absorbing very well. The absorption at 1.2 (m is related to the absorption in the visible part of the spectrum (rule of thumb: (1.2(m=(VIS/2).

One might consider increasing (max to match the IR-absorption characteristics of screen glass. According to Wiens displacement law this requires a decrease of the filament temperature T (by decreasing the applied voltage). The total energy output, however is, according to Stefan-Boltzmans law, proportional to T4. The net result always is a lower heat transfer to the screen glass!

The lamp is used in an aluminium reflector. The spectral energy distribution of the lamp reflector combination is different from the spectral energy distribution of the bare lamp. It changes at longer wavelengths and about 10% of the total energy is emitted at wavelengths above 2.7 (m, where screen glass has a high absorption (( ( 200 m-1). See graph 3.

Graph 3.In selective heating the screen is heated from the outside. The heat transfer mechanism can be described in a complicated way, taking into account the spectral energy distribution of the lamp+reflector, the spectral absorption of the screen glass and (multiple) reflections.

For engineering purposes some simplifications are used:

all (multiple) reflections are ignored

90% of the irradiation is absorbed by the screen glass with ( ( (VIS/2

10% of the irradiation is absorbed by the screen glass with ( = 200 m-1Besides the absorption coefficients (, the efficiency of heat transfer is related to the glass thickness, the amount of graphite on the screen inside (matrix transmission) and the IR absorbing properties of the graphite layer. A practical value for the graphite absorption is 70% (graphite thickness is (1 (m and the graphite layer is not completely closed on a microscopic scale).

The total IR absorption efficiency of screen glass can be approximated by:

( = f*(1-e-(sw.d) + (1-f)*(1-e-(lw.d) + (f.e-(sw.d + (1-f).e-(lw.d).(1-mxt).absgraphite{3}

(

: heat transfer efficiency

[-]

f

: fraction of short-wave IR in lamp-reflector energy = 90%

(sw

: absorption coefficient for short-wave IR ( (VIS/2

[m-1]

d

: glass thickness

[m]

(lw

: absorption coefficient for long-wave IR ( 200 m-1

[m-1]

mxt

: total matrix transmission (r+g+b)

[-]

absgraphite: IR-absorption graphite ( 70%

[-]

2.4.1 Short wave IR absorption data.

The short-wave IR absorption coefficient can be estimated from the known absorption coefficient for visible light: (sw ( (VIS/2.

A practical way of finding a good value for (sw is heating a matricised screen in an existing selective heating unit and using (sw as a parameter to fit the calculated temperature increase with the observed temperature increase.

2.4.2 Matrix transmission and glass thickness data.

In a real matricised screen the thickness (d) and the matrix transmission (mxt) are dependent on the position in the screen.

The glass thickness is calculated from the glass contour data and the centre glass thickness.

The contour data are expressed as polynomials:

hs(x,y) =

a1.x2 +

a2.x4 + a3.x6 +

{4}

b0.y2 + b1.x2.y2 + b2.x4.y2 + b3.x6.y2 +

c0.y4 + c1.x2.y4 + c2.x4.y4 + c3.x6.y4 +

d0.y6 + d1.x2.y6 + d2.x4.y6 + d3.x6.y6hs(x,y)= contour height with respect to centre

[mm]

s

= contour inside (i)/outside (o)

x,y

= position on screen

[mm,mm]

Note that h(x,y) on outside = o for real flat screenshs(x,y)ho(x,y)=0 for all (x,y)The glass thickness on a screen position (x,y) is given by:

d(x,y)= dcentre + hi (x,y) - ho(x,y)

{5}

d(x,y)= glass thickness on position (x,y)

[mm]

dcentre= centre glass thickness

[mm]

For the matrix transmission distribution a polynomial expression like {4} is used.

The coefficients of the polynomials can be obtained from the tube designers (e.g. LEG group within PPD).

2.4.3 Estimate of the heat transfer efficiency.

This unfriendly formula {3} can be simplified by assuming:

1-e-(sw.d ( (sw.d

(low absorption of short-wave IR)

1-e-(lw.d ( 1 (high absorption of long-wave IR)

This results in:

( = f. (sw.d + (1-f) + f. (1 - (sw.d).(1-mxt). absgraphite

{3a}

Example 1matricised CMT screen: f=0.9, mxt=0.4, absgraphite=0.7

Substitution in {3a} gives:

( = 0.48 + 0.52*(sw.d

{3b}

(sw = 10-25 m-1, d = 0.01-0.02 m ( ( = 50-70%

Example 2non-matricised CMT screen: f=0.9, mxt=1, absgraphite=0.7

Substitution in {3a} gives:

( = 0.10 + 0.90*(sw.d

{3b}

(sw = 10-25 m-1, d = 0.01-0.02 m ( ( = 20-55%

Note that:

the heat transfer efficiency is dependent on the glass transmission, higher transmission glass is heated up less than lower transmission glass.

the effect of glass thickness on the heat transfer efficiency is less for high transmission glass

the heat transfer efficiency of non-matricised screens with high transmission glass can be very low

2.5 Number of selective heating units (estimate)

The required number of selective heating units is dependent on:

required temperature increase

available heating time per heating position

glass thickness

available irradiance

heat transfer efficiency

The required temperature increase follows from the initial screen temperature (before selective heating) and the required functional screen temperature in the next process.

The available heating time follows from the line speed and the index time:

tavailable = 3600/Q - tindex

{6}

tavailable: available heating time on a heating position[s]

Q

: line speed[pcs/h]

tindex

: index time [s]

The available irradiance on a position (x,y) can be calculated with {2}.

The heat transfer efficiency on a position (x,y) is calculated by {3} using IR absorption data ((sw) and glass thickness and matrix transmission on this position.

For the glass properties default values are:

density

(= 2750 kg/m3

specific heat

Cp = 690 J/kg,(C

The estimated number of selective heating units is:

nheater= (. Cp. d. (T / (I. tavailable.()

{7}

nheater: estimated number of heaters

[-]

(

: glass density

[kg/m3]

Cp

: glass specific heat

[J/kg,(C]

d

: glass thickness

[m]

(T

: required temperature increase

[(C]

I

: irradiation

[W/m2]

tavailable: available heating time per heating position[s]

(

: heat transfer efficiency

[-]

In many cases the required temperature increase of the corners determines the required number of selective heating units because glass thickness in the corners is bigger and the available irradiation is the lowest.

2.6 Equalising

Heating creates a temperature profile in the glass in (x,y) because of glass thickness and irradiation (and heat transfer efficiency) differences and in (z) because of non-uniform IR absorption in the glass.

The dimensionless Fourier number contains the parameters influencing temperature equalising.

Fo = (/((.Cp).t /d2

{8}

Fo

: Fourier number

(

: thermal conductivity glass =1.03 W/m,(C

(

: density glass = 2750 kg/m3

Cp

: specific heat glass = 690 J/kg,(C

t

: time [s]

d

: glass thickness [m]

Fo ( 0.5 .t / d2 (t expressed in s, d expressed in mm)

For equalising Fo should be of order 1, meaning that gradients in cms glass will disappear in minutes of time. Gradients over longer distances (e.g. from centre to corner) will take considerably longer times to disappear. The temperature gradients (expressed in (C/m) in z-direction are bigger than in (x,y). Therefor, by approximation, screen temperature equalising is a one-dimensional heat diffusion problem.

The allowable temperature gradient after equalising in z-direction is 0.5(C/cm. This was defined as a compromise between length of equalising belt and screen processing robustness [4].

Design rule:

The allowable temperature gradient after equalising should not exceed 0.5(C/cm2.6.1 Numerical calculation of heating/equalising.

Calculation of the screen temperature profile in z-direction versus time requires solving the partial differential equation {9}(with boundary {10} and initial conditions {11}):

(.Cp.(T/(t = (.(2T/(x2 + A.I.(f.(sw.e-(sw.x + (1-f).(lw.e-(lw.x)

{9}

x = d (inside screen)

-(.(T/(x = ki.(T-Tambient) + A.I.(f.e-(sw + (1-f).e-(lw.(1-mxt).absgraphite){10a}

x = 0 (outside screen)

-(.(T/(x = ko.(T-Tambient)

{10b}

T = T0 , t=0 for all x

{11}

A

: heating on/off, A=0 (off), A=1 (on)

kI

: heat transport coefficient on screen inside [W/m2,(C]

ko

: heat transport coefficient on screen outside [W/m2,(C]

Tambient: ambient temperature[(C]

T0

: initial screen temperature [(C]

The second term on the right hand side of {9} describes the IR-heat absorption in the glass. The first term on the right hand side of {10} describes the heat exchange with the environment, the second term on the right hand side of {10a} describes the IR-absorption by the graphite.

The average of the heat transport coefficients can be determined by cooling down experiments [1], the ratio of the heat transport coefficients from theory (e.g. [2]).

The set of equations {9}-{11} is solved numerically by expressing the differentials (T/(t, (T/(x and (2T/(x2 as Taylors series and using the Du Fort and Frankel explicit solving scheme, which is stable for all (t and (x [3].

3 Using the Excel-tool

3.1 General information

The author developed an Excel tool for selective heating design. The file size is about 2.5MB.

All calculations are done on a screen quarter (north-east) to speed up computing time.

The tool supports heater designs with maximum 25 lamp/reflectors. For designs using more than 25 lamps, only lamp positions in the north-east quarter of the screen and (!) lamps of which the centre is within 30 cm of the borders of this quarter need to be entered. Lamps of which its centre is outside these borders do not contribute to the irradiation of the north-east screen quarter.

The workbook consists of 8 separate sheets:

INPUT: this sheet contains all the calculation algorithms. The sheet is protected except the fields that are used to enter data (A2:AA30). It is convenient if the area A2:M30 is visible, the remaining input fields in M2:AA7 (used for designs with more than 11 lamps) are accessible by scrolling to the right. The adjust scale button needs to be pressed if the screen dimensions are entered/changed. If you need to change more than one cell input at a time, it can be convenient to switch-off automatic calculation (Tools>Options>Calculation>Manual) and start calculation after input by pressing the F9-key. If not, Excel will let you wait a few seconds after every cell-entry.

lamp config: this sheet shows a sketch of the lamp-reflector combinations and the screen border. This sheet can be used to check for overlapping lamps (input errors). The dashed line is used for heater designs with more than 25 lamps. Lamp-reflector combinations that are outside (to west and/or south) this border do not contribute to the irradiation in the north-east screen quarter and entering their position is not required for proper calculations.

irrad. surface: this sheet shows a 3-D plot of the irradiation to the north-east quarter of a screen. This is used to identify gradients or dips in the irradiation distribution.

irrad. contour: this sheet shows a contour plot of the irradiation to the north-east quarter of a screen. Same purpose as previous sheet, but more convenient to identify the magnitude of the irradiation differences.

heating rate: this sheet shows the approximated heating rate of the glass. Note that this heating rate does not take heat exchange with the environment into account.

Tgrad.corner: this sheet shows the temperature gradient in the glass in the corner of the picture area and the maximum value that can be accepted for robust screen processing. The information is used to define the equalising time.

Tcorner: this sheet shows the temperature change on the in-/outside screen glass corner during heating and equalising. It is assumed that heating positions are separated by an equalising position.

Tcentre: same as previous sheet but then for the centre.

3.2 Tutorial getting used to the tool

Starting from scratch the INPUT sheet looks like this:

Step 1:

enter the screen dimensions, rounded to an even number of cms in cells K15 and K16 and press the Adjust Scale button. enter the centre positions of lamps in C5:AA6 and go to sheet lamp config to check for overlapping. Good practice is to start with a lamp in the centre (0,0) and fill up the screen area with lamps in a close packing.The input sheet should look like this:

and the lamp config sheet:

Step 2:

Switch on the lamps by entering 1 in the cells C7:AA7 Goto sheet irrad.surface

The surface plot of the irradiation pattern shows very low values in the screen corner. This can easily be corrected by adding lamps to the corners:

A reasonably flat irradiation distribution is obtained after adding a sufficient number of lamps or by increasing the lamp pitch in x- and or y-direction.

In the next step the heating rates of the screen will be optimised. This requires input of screen geometry (glass contour, matrix transmission, glass thickness, IR-absorption coefficient). As an example 17CMT-Cyber data will be used

Step 3:

enter screen data in bright green area (A9:K22) of the input sheet go to sheet heating rate and check with requirements with respect to temperature increase in centre/corners.The INPUT sheet:

The heating rate sheet:

The heating rate in the screen corner is much lower than in the screen centre. The major cause in this case is the glass wedge, because the irradiation pattern was almost flat.

To check the seriousness of this problem the data in the light green area (A24:K26) should be filled in. As an example a lower temperature increase of the corners compared to the centre is accepted.

For the required temperature increase in the corners 4 (>3.6) positions are needed, for the required temperature increase in the centre 2 (>1.7) positions are needed. This is an indication that the heating rate to the corners indeed is too low. To meet both temperature requirements within one heater design the lamps should be divided in electrical groups with different heating times. The relative heating time to the corners is set to 1, the relative heating time to the centre lamps to a value 400 s.

The inside glass temperature (functional temperature for screen coating) at t=400 s is for centre and corner respectively 32.9 and 31.9(C. The required temperatures after equalising for centre and corner are 34 (=23+11) and 32 (=23+9) (C.

This (small) delta can be corrected by increasing the relative heating time from 0.30 to 0.35.

Required selective process:

heating time

: 75s (5 positions)

equalising time: 400s (from start heating)

(200s (after end heating)

Selective heating unit design:

15 lamp-reflector combinations

3 electrical groups

dimension: 57 cm * 45 cm

3.3 Further reading

Selectieve Verwarming, een methode voor het gelijkmatig opwarmen van schermglas, Gert-Jan Hufken, Augustus 1994

New selective heating belt for Jumbo line in Aachen, Ivo Durlinger, TVB-698-00-ID-D055, 2000-06-06

Selective heating Fcline 51FS Hua Fei design justification, Ivo Durlinger, TVR-57-96-ID-D0153, 1996-07-02

Selective Heating Fcline PDC design justification, Ivo Durlinger, TVR-57-95-ID/D433, 1995

Selective heating new Large/Jumbo lines, Ivo Durlinger, TVR-698-00-ID/D031, 2000-03-27

Selective heating the effect of equal heating time distribution on temperature equalising and robustness to incoming screen temperature variations, Ivo Durlinger, TVR-698-00-ID-D033, 2000-05-24

3.4 Advanced options

For options 3.4.2 3.4.4., the INPUT sheet needs to be unprotected. For an unprotected version, contact the author.

3.4.1 Lamp axis parallel to short screen side

In some special cases it can be needed to change the orientation of the lamp-reflector combinations with respect to the screen. This only requires swapping x and y coefficients in the glass inner contour and matrix transmission description and screen length/ screen width (in bright green area of INPUT sheet).

3.4.2 The use of a different radiator.

The program is capable (with some limitations) of using other radiators. The INPUT sheet needs to be unprotected. The dimensions of the radiator need to be entered in the bright blue section of the INPUT sheet located (F81:I95). The length/cross wise irradiation distribution need to be entered in the bright blue section of the INPUT sheet located (A34:D68). Note that the use of radiators other than IR-Quartz in a aluminium reflector may require adaptation of the radiation data in section (A70:D75).

3.4.3 Changing physical constants of the glass

The physical constants can be changed in the bright blue section of the INPUT sheet located at (A77:D80). First unprotect the sheet

3.4.4 Changing heat exchange to ambient.

The heat transport coefficients can be changed in the bright blue area in the INPUT sheet located at (A82:D83). First unprotect the sheet.

In the following section, list all (and only) those documents you referred to in your report.

How to add a reference:

1Place the cursor somewhere in the Reference section.

2Click +Ref.

3A new reference will be added just after the reference your cursor was in.

4You will be asked for the suffix of the Reference Bookmark (see Using references). All Reference Bookmarks start with AAARef5If the Reference Bookmark already exists, you get a message and may try again.

6Click OK to add the Reference. Youll have to add the other information.

7Click Cancel to cancel the addition of the new reference.

Note:If you mark the checkbox Replace Existing, you can overwrite an already existing Reference Bookmark. This means that the reference to which it originally belonged, no longer has a bookmark. You can not refer to it anymore, unless you manually add a new bookmark.

Any references you made already, are now coupled to the newly added reference!

Using references:Anywhere in your document, you can refer to the number of a reference (if it has a bookmark). To do so:

1Place the cursor at the exactpoint where you want the reference number to appear.

2Select Insert > Cross-reference.

3Select Bookmark from Reference Type

4Select Paragraph Number from Insert Reference To5Select your Reference Bookmark from For Which Bookmark6Click OKReferences are updated automatically if you click Update.

References

[1] Heating/cooling of screens in Ambient, Ivo Durlinger, TVB-698-00-D052, 2000-04-11.

[2] Dubbel-Taschenbuch fuer den Maschinenbau, Sass, Bouche, Leitner, p.475, 1970

[3] Handbook of Applicable Mathematics, Vol.3, Numerical Methods, Robert F. Churchhouse, John Wiley & Sons, 1981

[4] Selective Heating New Large/Jumbo Lines, Ivo Durlinger, TVR-698-00-ID/D031, 2000-03-27

Abbrevations in alphabetical order

Philips Components B.V.

Display Components Eindhoven