diff --git a/openslides/agenda/projector.py b/openslides/agenda/projector.py
index c93e70124..b318ba5d6 100644
--- a/openslides/agenda/projector.py
+++ b/openslides/agenda/projector.py
@@ -1,5 +1,6 @@
 from ..core.config import config
 from ..core.exceptions import ProjectorException
+from ..utils.collection import CollectionElement
 from ..utils.projector import ProjectorElement
 from .models import Item
 
@@ -60,10 +61,13 @@ class ListOfSpeakersSlide(ProjectorElement):
                     # Yield last speakers
                     yield speaker.user
 
-    def need_full_update_for_this(self, collection_element):
-        # Full update if item changes because then we may have new speakers
-        # and therefor need new users.
-        return collection_element.collection_string == Item.get_collection_string()
+    def get_collection_elements_required_for_this(self, collection_element, config_entry):
+        output = super().get_collections_required_for_this(collection_element, config_entry)
+        # Full update if item changes because then we may have new
+        # candidates and therefor need new users.
+        if collection_element == CollectionElement.from_values(Item.get_collection_string(), config_entry.get('id')):
+            output.extend(self.get_requirements_as_collection_elements(config_entry))
+        return output
 
 
 class CurrentListOfSpeakersSlide(ProjectorElement):
diff --git a/openslides/assignments/projector.py b/openslides/assignments/projector.py
index 6e61fb513..fac925372 100644
--- a/openslides/assignments/projector.py
+++ b/openslides/assignments/projector.py
@@ -1,4 +1,5 @@
 from ..core.exceptions import ProjectorException
+from ..utils.collection import CollectionElement
 from ..utils.projector import ProjectorElement
 from .models import Assignment, AssignmentPoll
 
@@ -46,7 +47,10 @@ class AssignmentSlide(ProjectorElement):
                     for option in poll.options.all():
                         yield option.candidate
 
-    def need_full_update_for_this(self, collection_element):
+    def get_collection_elements_required_for_this(self, collection_element, config_entry):
+        output = super().get_collection_elements_required_for_this(collection_element, config_entry)
         # Full update if assignment changes because then we may have new
         # candidates and therefor need new users.
-        return collection_element.collection_string == Assignment.get_collection_string()
+        if collection_element == CollectionElement.from_values(Assignment.get_collection_string(), config_entry.get('id')):
+            output.extend(self.get_requirements_as_collection_elements(config_entry))
+        return output
diff --git a/openslides/core/models.py b/openslides/core/models.py
index 4088c26e9..926bc3073 100644
--- a/openslides/core/models.py
+++ b/openslides/core/models.py
@@ -116,7 +116,7 @@ class Projector(RESTModelMixin, models.Model):
                     result[key]['error'] = str(e)
         return result
 
-    def get_all_requirements(self, on_slide=None):  # TODO autoupdate: Refactor or rename this.
+    def get_all_requirements(self):
         """
         Generator which returns all instances that are shown on this projector.
         """
@@ -131,50 +131,35 @@ class Projector(RESTModelMixin, models.Model):
             if element is not None:
                 yield from element.get_requirements(value)
 
-    def collection_element_is_shown(self, collection_element):
+    def get_collection_elements_required_for_this(self, collection_element):
         """
-        Returns True if this collection element is shown on this projector.
+        Returns an iterable of CollectionElements that have to be sent to this
+        projector according to the given collection_element and information.
         """
-        for requirement in self.get_all_requirements():
-            if (requirement.get_collection_string() == collection_element.collection_string and
-                    requirement.pk == collection_element.id):
-                result = True
-                break
+        from .config import config
+
+        output = []
+        changed_fields = collection_element.information.get('changed_fields', [])
+        if (collection_element.collection_string == self.get_collection_string() and
+                changed_fields and
+                'config' not in changed_fields):
+            # Projector model changed without changeing the projector config. So we just send this data.
+            output.append(collection_element)
         else:
-            result = False
-        return result
-
-    @classmethod
-    def get_projectors_that_show_this(cls, collection_element):
-        """
-        Returns a list of the projectors that show this collection element.
-        """
-        result = []
-        for projector in cls.objects.all():
-            if projector.collection_element_is_shown(collection_element):
-                result.append(projector)
-        return result
-
-    def need_full_update_for_this(self, collection_element):
-        """
-        Returns True if this projector needs to be updated with all
-        instances as defined in get_all_requirements() because one active
-        projector element requires this.
-        """
-        # Get all elements from all apps.
-        elements = {}
-        for element in ProjectorElement.get_all():
-            elements[element.name] = element
-
-        for key, value in self.config.items():
-            element = elements.get(value['name'])
-            if element is not None and element.need_full_update_for_this(collection_element):
-                result = True
-                break
-        else:
-            result = False
-
-        return result
+            # It is necessary to parse all active projector elements to check whether they require some data.
+            this_projector = collection_element.collection_string == self.get_collection_string() and collection_element.id == self.pk
+            collection_element.information['this_projector'] = this_projector
+            elements = {}
+            for element in ProjectorElement.get_all():
+                elements[element.name] = element
+            for key, value in self.config.items():
+                element = elements.get(value['name'])
+                if element is not None:
+                    output.extend(element.get_collection_elements_required_for_this(collection_element, value))
+            # If config changed, send also this to the projector.
+            if collection_element.collection_string == config.get_collection_string():
+                output.append(collection_element)
+        return output
 
 
 class ProjectionDefault(RESTModelMixin, models.Model):
diff --git a/openslides/motions/projector.py b/openslides/motions/projector.py
index efee87177..07e006bfa 100644
--- a/openslides/motions/projector.py
+++ b/openslides/motions/projector.py
@@ -1,4 +1,5 @@
 from ..core.exceptions import ProjectorException
+from ..utils.collection import CollectionElement
 from ..utils.projector import ProjectorElement
 from .models import Motion
 
@@ -26,10 +27,13 @@ class MotionSlide(ProjectorElement):
             yield from motion.submitters.all()
             yield from motion.supporters.all()
 
-    def need_full_update_for_this(self, collection_element):
+    def get_collection_elements_required_for_this(self, collection_element, config_entry):
+        output = super().get_collection_elements_required_for_this(collection_element, config_entry)
         # Full update if motion changes because then we may have new
         # submitters or supporters and therefor need new users.
         #
         # Add some logic here if we support live changing of workflows later.
         #
-        return collection_element.collection_string == Motion.get_collection_string()
+        if collection_element == CollectionElement.from_values(Motion.get_collection_string(), config_entry.get('id')):
+            output.extend(self.get_requirements_as_collection_elements(config_entry))
+        return output
diff --git a/openslides/utils/autoupdate.py b/openslides/utils/autoupdate.py
index a1209d7bb..18ec21e9b 100644
--- a/openslides/utils/autoupdate.py
+++ b/openslides/utils/autoupdate.py
@@ -23,22 +23,6 @@ def get_logged_in_users():
     return User.objects.exclude(session=None).filter(session__expire_date__gte=timezone.now()).distinct()
 
 
-def get_projector_element_data(projector, on_slide=None):  # TODO autoupdate
-    """
-    Returns a list of dicts that are required for a specific projector.
-
-    The argument projector has to be a projector instance.
-
-    If on_slide is a string that matches an slide on the projector, then only
-    elements on this slide are returned.
-    """
-    output = []
-    for requirement in projector.get_all_requirements(on_slide):
-        required_collection_element = CollectionElement.from_instance(requirement)
-        output.append(required_collection_element.as_autoupdate_for_projector())
-    return output
-
-
 @channel_session_user_from_http
 def ws_add_site(message):
     """
@@ -81,7 +65,10 @@ def ws_add_projector(message, projector_id):
             Group('projector-{}'.format(projector_id)).add(message.reply_channel)
 
             # Send all elements that are on the projector.
-            output = get_projector_element_data(projector)  # TODO autoupdate
+            output = []
+            for requirement in projector.get_all_requirements():
+                required_collection_element = CollectionElement.from_instance(requirement)
+                output.append(required_collection_element.as_autoupdate_for_projector())
 
             # Send all config elements.
             collection = Collection(config.get_collection_string())
@@ -102,59 +89,25 @@ def ws_disconnect_projector(message, projector_id):
     Group('projector-{}'.format(projector_id)).discard(message.reply_channel)
 
 
-def send_data(message):  # TODO autoupdate
+def send_data(message):
     """
-    Informs all users about changed data.
+    Informs all site users and projector clients about changed data.
     """
     collection_element = CollectionElement.from_values(**message)
 
-    # Loop over all logged in users and the anonymous user.
+    # Loop over all logged in site users and the anonymous user and send changed data.
     for user in itertools.chain(get_logged_in_users(), [AnonymousUser()]):
         channel = Group('user-{}'.format(user.id))
-        output = collection_element.as_autoupdate_for_user(user)
-        channel.send({'text': json.dumps([output])})
+        output = [collection_element.as_autoupdate_for_user(user)]
+        channel.send({'text': json.dumps(output)})
 
-    # Get the projector elements where data have to be sent and if whole projector
-    # has to be updated.
-    if collection_element.collection_string == config.get_collection_string():
-        # Config elements are always send to each projector
-        projectors = Projector.objects.all()
-        send_all = None  # The decission is done later
-    elif collection_element.collection_string == Projector.get_collection_string():
-        # Update a projector, when the projector element is updated.
-        projectors = [collection_element.get_instance()]
-        send_all = True
-    elif collection_element.is_deleted():
-        projectors = Projector.objects.all()
-        send_all = False
-    else:
-        # Other elements are only send to the projector they are currently shown
-        projectors = Projector.get_projectors_that_show_this(collection_element)
-        send_all = None  # The decission is done later
-
-    broadcast_id = config['projector_broadcast']
-    if broadcast_id > 0:
-        projectors = Projector.objects.all()  # Also the broadcasted projector should get his data
-        send_all = True
-        broadcast_projector_data = get_projector_element_data(Projector.objects.get(pk=broadcast_id))
-        broadcast_projector_data.append(CollectionElement.from_values(
-            collection_string=Projector.get_collection_string(), id=broadcast_id).as_autoupdate_for_projector())
-    else:
-        broadcast_projector_data = None
-
-    for projector in projectors:
-        if send_all is None:
-            send_all = projector.need_full_update_for_this(collection_element)
-        if send_all:
-            if broadcast_projector_data is None:
-                output = get_projector_element_data(projector)
-            else:
-                output = broadcast_projector_data
+    # Loop over all projectors and send data that they need.
+    for projector in Projector.objects.all():
+        if collection_element.is_deleted():
+            output = [collection_element.as_autoupdate_for_projector()]
         else:
-            # The list will be filled in the next lines.
-            output = []
-
-        output.append(collection_element.as_autoupdate_for_projector())
+            collection_elements = projector.get_collection_elements_required_for_this(collection_element)
+            output = [collection_element.as_autoupdate_for_projector() for collection_element in collection_elements]
         if output:
             Group('projector-{}'.format(projector.pk)).send(
                 {'text': json.dumps(output)})
diff --git a/openslides/utils/projector.py b/openslides/utils/projector.py
index 89ae0a6a4..5f3686211 100644
--- a/openslides/utils/projector.py
+++ b/openslides/utils/projector.py
@@ -1,5 +1,6 @@
 from django.dispatch import Signal
 
+from .collection import CollectionElement
 from .dispatch import SignalConnectMetaClass
 
 
@@ -73,11 +74,31 @@ class ProjectorElement(object, metaclass=SignalConnectMetaClass):
         """
         return ()
 
-    def need_full_update_for_this(self, collection_element):
+    def get_requirements_as_collection_elements(self, config_entry):
         """
-        Returns True if this projector element needs to be updated with all
-        instances as defined in get_requirements(). The given
-        collection_element contains information about the changed instance.
-        Default is False.
+        Returns an iterable of collection elements that are required for this
+        projector element. The config_entry has to be given.
         """
-        return False
+        return (CollectionElement.from_instance(instance) for instance in self.get_requirements(config_entry))
+
+    def get_collection_elements_required_for_this(self, collection_element, config_entry):
+        """
+        Returns a list of CollectionElements that have to be sent to every
+        projector that shows this projector element according to the given
+        collection_element and information.
+
+        Default: Returns only the collection_element if it belongs to the
+        requirements but return all requirements if the projector changes.
+        """
+        requirements_as_collection_elements = list(self.get_requirements_as_collection_elements(config_entry))
+        for requirement in requirements_as_collection_elements:
+            if collection_element == requirement:
+                output = [collection_element]
+                break
+        else:
+            if collection_element.information.get('this_projector'):
+                output = [collection_element]
+                output.extend(requirements_as_collection_elements)
+            else:
+                output = []
+        return output