Problems defining the pattern to extract multiple dates from a json string in java

I have the following code:

    public static void main(String[] args) {
    String str = "{\"$and\":[{\\\"$or\\\":[{\\\"origen\\\":{\\\"$eq\\\":\\\"LEMD\\\"}},{\\\"origen\\\":{\\\"$eq\\\":\\\"LEBL\\\"}}]},{\"horasacta\":{\"$gte\":\"28/02/2015 00:00:00\"}},{\"horasacta\":{\"$lte\":\"28/02/2015 23:59:59\"}}]}";

    Pattern pattern = Pattern.compile("\\{\"(.*?)\":\\{\"\\$(.*?)\":\"[0-9]+/[0-9]+/[0-9]+ [0-9]+:[0-9]+:[0-9]+\"}}");
    Matcher matcher = pattern.matcher(str);
    while (matcher.find()) {
        System.out.println(matcher.group(0));
    }

I want to get the substrings:

{\"departure\":{\"$gte\":\"28/02/2015 00:00:00\"}}
{\"departure\":{\"$lte\":\"28/02/2015 23:59:59\"}}

but the program give me:

{"$and":[{\"$or\":[{\"origin\":{\"$eq\":\"LEMD\"}},{\"origin\":{\"$eq\":\"LEBL\"}}]},{"departure":{"$gte":"28/02/2015 00:00:00"}}
{"departure":{"$lte":"28/02/2015 23:59:59"}}

the 2nd time the find() matches the pattern but the 1st time it doesn't do the job.

Any help?

thanks