Since HTML5\'s translate-method moves the origin of drawing relatively to its former origin apparently. (when I use ctx.translate(20,20) twice in a row I get the same result
You can do that by using .save() and .restore()
ctx.save();
ctx.translate(// do some translations);
// draw whatever
ctx.restore();
You need to call save() to "save" the current contexts state. Then you can perform translations, rotations, etc. After your finished call restore() to reset the context's state to what it was when you initially called save().
Live Demo
MDN Tutorial also explaining it