Hello, sorry that you didn't hear from me the last days, but I was too busy!
Now ich found the reason for my problem konverting 4C-images into B/W-pictures! When I change my 4C-image over "Mode" > "grayscale-picture" (Photoshop), the PDF-result will be a 4C-image!
However when I konvert this 4C-image over "setting level" > "black and white", I'll get the desired B/W-PDF.
I hope, you understand what I try to explain, because I use my Photoshop as a German version. So I'm likely not be able to the correct English terms.
Thanks to all who tried to help me and have a nice christmastime!!!
Thank you so much walt.farrel. That's really a good and easy way! I have tried the method Haakoo suggested (creating a text style) and
succeded too, but your method is great. So, many thanks to all the nice fellows who spent their time to help me.
Now I can begin solvin the other problem (placing a Black and White-Image without changing into a '4- or 3-colour picture depending on CMYK or RGB).
I hope you to have some further good Advices for that Problem!