Polaroid SX70 manuale d’uso

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I - DESCRIPTION The Polaroid Land SX-70 is a folding, pocket sized, single-lens reex camera which takes and immediately delivers full-color pictures approximately 31/4 inches square (see gures 1-1, 1-2 and 1-3). Operation is automatic; the user merely inserts the lm, focuses and shoots. power is provided by a six-volt battery inside the ?[...]

The subject is viewed and focused throught the taking lens, a mirror , a Fresnel viewing screen (with spilt-image focusing aid) and a optical system to focus the image at the viewing eye- piece. As in all single-lens reex cameras, the shutter must be open to provide an image at the eye-piece. This requirement is fullled by the automatic elect[...]

When the camera is fully opened, the interlock switch (S6), located at the left rear corner of the mirror cover , is closed and the battery is connected to the camera electrical circuit. (Figure 1-4). The front coverlatchis located on the right side of the camera just inside the rim of the bottom cover assembly . Pressing down on this yellow latch [...]

Thus, the cover must be fulled closed, the gears engaged, and the latch fully seated, in order to actuate the drive motor . As S7 closes, power is applied to the drive motor (S8 is also involved and is discussed in a following paragraph), the gear train is set in motion and actuates a device called the lm pick. The pick engages the dark slide, p[...]

shutter to initiate a series of events. The shutter blades close to cut off the optical path. The hinged Fresnel viewing screen is swung upward and comes to rest in front of the xed viewing mirror (Figure 1-8 B). The shutter opens and closes to perform the exposure function. A rst-surfaced taking mirror is fastened to the underside of the Fre[...]

slide. The counter will start at number 10. Since switches S8 and S9 are physically attached to the counter , the camera will cycle through 10 exposures even though there be less than 10 sheets of lm in the pack. This deviation must be recognized whenever a partially exposed pack is used. The image is reected by the mirror onto the lm surf[...]

When through using camera it be can folded and latched in its closed conguration by pushing the erecting link. When the camera is closed, the interlock switch (S6) is opened so that the battery is completely disconnect from the camera circuits. The trim wheel (the lighten / darken adjustement associated with the photocell) automatically returns [...]

When the release button is pressed, a switch S1 closes (Figure 1-1 1 A and B) and applies operating power to the shutter . As soon as power is applied to the shutter , solenoid #1 is energized and rapidly moves the shutter blades to the closed position. When the solenoid has reached the end of its stroke (shutter closed, it no longer requires maxim[...]

to an adequate level to hold the solenoid after the high-current circuit has completed the solenoid operating function and switches on the motor drive circuit. Thus, the shutter will remain closed, with minimum battery drain. Light entering the lens is now cut off and the reex mirror is swung upward to picture-taking position. The electronic lat[...]

mechanical device identied as the interceptor connected to the lens focusing mecchanism (Figure 1-13 A). the interceptor is moved as the lens is focused regardless of whether ambient-light or ash pictures are being taken. When ash bar is in place (S2 closed) and the gear train opens switchs S5 (Fighure 1-14), solenoid #2 is energized and p[...]

Figure 1-14 S5 being opened by the recock ram (Gear train) Figure 1-13 B Interceptor link, Solenoid 2, S2 operation - Solenoid energized[...]

In cameras with «P» conguration or later shutter there is no ambient light measurement made. If a ash bar is in the shutter socket a ash picture will result regardless of the ambient light level. On early cameras, an ambient light measurement is made during the ash delay period. Since the photocell aperture is a part of the shutter bl[...]

II - THEOR Y OF OPERA TION A general description of the camera and the sequence of its functions is contained in Section I. In that section, detailed analysis of individual assemblies and electrical circuits was minimized so that emphasis could be placed on the intenelation-ship of various functions. In the following paragraphs, the individual grou[...]

the subject passes through the camera lens and is reected by the viewing mirror (on the inside surface of the mirror cover) to the Fresnel viewing screen. The entire subject image is now reproduced on the viewing screen. At this point, viewnder optics must be employed for focusing. The optics must transfer the image from the viewing screen to[...]

The screen itself is a sheet of plastic upon which are impressed series of concentric rings much like the grooves pressed into a phonograph record (Figure 2-3) instead of having a vee shaping; however , the grooves in the Fresnel screen form a saw-tooth with a tooth angle increasing slightly with each successive groove in such a manner as to comple[...]

mirror , the 6-edges viewing mirror is used in the optical path twice. First, the light rays entering the camera from the taking lens are reected onto the Fresnel screen by the viewing mirror . Secondly , the operator views the image on the screen with light reecting off the viewing mirror (Figure 2-1). (The viewing mirror is located on the u[...]

The entire ECM (rather tna its individual integrated circuits) is used as a remplacement item. For that reason, the theory of operation and analysis techniques presented in this manual have prepared in such a way that the repairman can relate a specic camera failure mode to an ECM function. Figure 2-6 SX-70 Switch locations a- Switch S1 is actua[...]

Figure 2-7 S3 Being opened by recock ram c- Switch S3, normally closed at the begining of the exposure cycle is opened by the recock ram located in the gear train assembly . See Figure 2-7. As the exposure sequence begins, S3 opens and actuates a delay circuit (Y delay) in the EMC which retards the start of the actual exposure approximately 40 mill[...]

Figure 2-8 S4 Switch operating congurations damage to the circuit in the event that ashbulb becomes short-circuited after it is red. e- Switch S5 (normally closed at the beginning of the exposure cycle), like S3, is located in the gear train and actuated by the recock ram (Figure 2-7). When the gear train rotates to appropriate point in it[...]

Figure 2-8 A S8 - S9 Exposure counter switches h- Switch S8 (Figure 2-8 A) is part of the exposure counter operated by the counter wheel. As S7 closes, power is applied, ejecting the dark slide. After the dark slide ejection, the counter wheel turns, opening S8. S8 then remains open until the lm pack is removed. When the pack is taken out, S8 cl[...]

mechanical coupling device set the exposure counter to the position just before the rst exposure and closed S8, but since S7 has removed all battery power no action occurs). h- At the end of the 40 millisecond delay period, the ECM removes power from solenoid #1 and the shutter opens. Simultaneously , the circuit starts timing the exposure (inte[...]

k- If the operator has removed pressure from exposure button all power will be removed and the shutter blades will open to permit viewing. If the button has not been released, the shutter blades will remain closed until the operator removes his nger from the button. at the aperture for ash exposure at the set distance (Figure 1-13). The inter[...]

The following paragraphs describe the manner in which the mechanical components of the shutter respond to either manual or electrical direction. 1. When the operator prepares to take a picture, he rst must aim and focus the camera. As he rotates the focus wheel to bring the split Fresnel image into focus, a cam molded into the rear surface of th[...]

Figure 2-9 A Solenoid S2 operation 2. When an ambeint light exposure is being made, all of the action just described takes place but does not affect the shutter action. However , when a ash array is inserted switch S2 in the ash socket programs the electronics to energize solenoid #2. The impact of this action on the movement of the shutter b[...]

Figure 2-10 Spread roller system The basic theory of the lm processing method remains unchanged from previous Polaroid system. That is , the developping chemistry is encapsuled in a pod on each sheet of lm and, as the sheet is passed between rollers, the pod is burst and the chemical spread evenly between the negative and the mylar protective[...]

partial pack : the top of the sheet of lm would be ejected as a dark slide and the counter would registrer «10». After the last actual sheet is used, the camera would still function until «0» is reached. If a ash bar were attached, and an unused bulb was available after the last lm sheet was used, attempting to make another exposure wo[...]

CLOSED BY OPER TOR S4 SWITCHES AC to BC S4 SWITCHES AC to BC CLOSES CLOSES S1 S4 BC S4 BC S4 AC End "Y" S5 S3 S3 S5 ST 2 S1 T - 0 S2 → Closed if flash array inserted Solenoid #2 power up (S2 closed) ● S9 opens when previous pack removed ● S6 closed during the erecting mode ● S8 closed until film cover ejected ● Gears between fro[...]

III - TROUBLESHOOTING The Sx-70 camera is an electronically controlled device, the electronics being in the integrated circuits (IC) mounted in the Electronic Control Modul (ECM) and Flash Fire Assembly (FF A) in the shutter housing and in the Motor Control Circuit (MCC) in the camera back. Because the IC’s are non-reparaible items, there is no r[...]

SX-70 CMAERA REP AIR INSPECTION PROCEDURE A. FUNCTIONAL TEST 1. Perform light leak test. 2. Check focus and trim wheel torque. 3. Check trim wheel reset ±2 teeth and front cover to shutter gap. 4. Cycle camera 3 times at 5.0 and 6.4 volts with power pack. 5. Focus camera at 8’ - performe aperture test (see specication sheet). 6. Ambient mode [...]

Figure 3-2 SX-70 Collimator Figure 3-1 Film pack simulator and power suplly Checkout the SX-70 camera requires the use of several pieces of test equipment. The purpose of this section is to instruct you in the proper use of this equipment. 1. Po we r s up pl y an d pa c k si m ul at or (F ig u re 3 -1 ) In use the system subsitutes for the lm pa[...]

Figure 3-2 T ypical collimation conditions Figure 3-3 Location of new collimator target a. Collimation of the Split Image Viewing System. NOTE : If the collimator is not available, set the focus wheel to innity and look at a scene at least 200 feet away . Observe that the focus is sharp within a tolerance of -1 tooth to +2 teeth beyond the in[...]

Figure 3-5 Disengaging the idler gear (2) Open the camera front cover slide the camera onto the horn of the collimator . Make sure that the camera is all the way on the horn so that the camera is captured by the spring latches. (3) Swing the collimator innity lens to its vertical position. (Be sure the 8’ lens is not in the viewing path.) (4) [...]

(8) Look through the camera and observe the vertical line target. Compare the observed image with Figure 3-4 to determine if the camera is within specications. NOTE : There is no separate close-focus adjustement on the camera. if the focus wheel has reached its stop before maximum resolution is achieved, return to the innity check. If there i[...]

b. Ambient mode exposure test (1) Place the S2 switch int he OPEN position. Set the voltage to 5.8 volts (2) Set the light level selector to the desired 100 light level (3) Slide the camera over the horn on the tester . The camera should go through the dark slide (S8) cycle. If not, remove the camera from the horn, determine the cause of failure, a[...]

more times. The READY and FLASH indicator lamps should sequence as in step 3. (6) On the ash simulator assembly , press and release the RESET button. (7) Press the exposure button actuator . The number one READY indicator lamp should remain lighted and the number one FLASH indicator should not light. (Checks S9.) NOTE : The toggle switches on th[...]

(4) Slide the camera fully onto the horn. (5) Select the light level desired on the Comparalumen and slide the horn up against the appropriate window . (Position the horn so that the locating pad on the front of the horn touches the window .) (6) Insert a remote shutter release cable into the socket on the right side of the shutter . (7) Rotate the[...]

camera in the mirror up picture taking position). (Both of these tests must be done in a darkened aera.) a. Static tests (1) Erect the camera and remove the front cover assembly . Close S7. (2) T urn on the power supply and insert the light leak xture into the camera lm compartment. The camera should run through the dark slide eject cycle. (3[...]

Figure 3-10 Manual camera tester c. Install the ash simulator board into the camera ashbar socket in the same way as a ashbar would be installed . d. Press the red exposure button, S1. e. Observe that LED #1 ashes. f. Flip switch S1 up. g. Press the red exposure button. h. Observe that LED #2 ashes. i. Flip switch S2 up. j. In like m[...]

MANUAL FUNCTION TEST SEQUENCE T est Mode Action Shutter Response S6/S7 Close S6/S7 Press and release S1 button to check for mechanical binding. Observe current drain. No reaction (Blades open, motor off) AMBIENT Exposure Mode Remove ash array from shutter . Close S1 Open S5 Open S1 Open S3 Close S3 Close S5 Blades close; motor runs Blades close;[...]

Figure 3-1 1 SX-70 Viewnder system Figure 3-12 Installing the exit pupil gage Viewnder quality refers to the general quality and alignment of the camera optics. For the user , it can be precisely dened as the appearance and clarity of the image as seen through the viewing system (Figure 3-1 1). When a camera has poor viewnder quality , [...]

Figure 3-14 Exit pupil images Figure 3-13 Aligning the exit pupil gage (3) The mounting rails for the gage must be ush with the eyelens frame. Check by holding the bottom of the eyelens frame with the thumb and apply slight pressure in the upper front of the gage with the right index nger . The gage should be secure. NOTE : A left handed pers[...]

Figure 3-15 Identifying distorted mirrors 3. Concave Mirror Distortion Check a. Focus on a target which presents a clear vertical line (for example a door frame). b. Scan the camera horizontally . c. If the mirror is not distorted, the vertical line seen in the eyepiece will vary at the camera is scanned. At either side of the eld, the line will[...]

Figure 3-16 Fresnel standards chart you to a chart. In all cases, the fault analysis charts present the logical sequence of checks and remedial procedures. These charts are divided into three parts : - one, (CAMERA ANAL YSIS) for problem analysis when the camera is completely assembled - two, (OPTICAL ANAL YSIS) for analysis of the viewnder part[...]

Figure 3-18 Flex circuit terminal locations 1. Camera/Shutter Isolation T o expedite the repair procedure, it is essential that the malfunction be isolated to either the camera back or the shutter as early as possible in the troubleshooting procedure. The sequence should not be considered inexible, however . a. Disassemble the camera to the poin[...]

Figure 3-19 T est points on SX-70 shutters Figure 3-18 T esting instrument connections d. With the 1000 ohm resistor still in place, connect a jumper wire between the motor (minus TP9 contact) and the battery (minus TP1 contact) for a moment : (1) If the motor runs, the MMC is defective. (2) If the motor does not run, the motor is defective e. Remo[...]

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IV - REP AIR AND ADJUSTMENTS This section of the manual is primarily devoted to disassembly/reassembly procedures. These procedures provide step by step instructions aimed at guiding the technician through the intricacies of SX-70 camera repair . The procedures cover such things as replacement of improper linkages or connections, repair of electric[...]

Figure 4-1 Front cover hinge studs Figure 4-2 Comparison of spread roll brackets (4) Close the front cover and recheck; bend further if necessary . (5) With the front cover open, observe for a clearance between the latch and the 3 rd idler gear . (6) Observe that the stop pin (Figure 4-3) is not resting on the outer plate when the front cover is cl[...]

Figure 4-4 Comparison of decal before and after front cover closure Figure 4-3 Bending the stop latch[...]

Figure 4-5 New spread roll conguration 1. Interference Between Front and Bottom Covers A few cameras may have an interference t between the S7 actuator post and the edge of the bottom cover when the front cover is opened. The problem has been traced to slightly oversize bottom covers. Problem bottom covers have a mark «PP 2½». One method o[...]

Figure 4-6 Front cover light shield cam Figure 4-7 Replacing light shield cam When a new type shutter is installed, the cam in the light shield must be inspected and changed if necessary . The new cam should be installed in the same place and manner as the old cam (Figure 4-7). Remove the old cam uising an x-acto knife to cut the plastic rivets. Pl[...]

Figure 4-9 Shutter mount retaining screws 5 . In the following step, the bottom cover will be removed. T o prevent damage to the ex circuit, insert a thin strip (a small, metal, six-inch pocket scale, for example) between ex circuit and the inside cover surface. Move the tool from one locating stud to the other as the cover is being removed t[...]