M-20 J (201) / Allegro
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Flight Instructor
Flight Crew Last 90 Days 10; Flight Crew Total 1400; Flight Crew Type 840
Communication Breakdown; Distraction
Conflict NMAC
General None Reported / Taken
Human Factors
I was on a 45 degree entry to the traffic pattern for RWY XX at ZZZ. A Cessna was on downwind around midfield.  As I approached downwind; I didn't see an Arrow on crosswind until we were almost head-to-head at a short distance. His profile from my perspective was head-on and relatively hard to see; and he may have been behind the a-pillar of my windshield.  I don't believe he made a radio call for takeoff from ZZZ.Factors were:1) Distraction by the need of maintaining distance from the Cessna in front.2) Inconspicuous profile; possible obstruction by my airplane; and background clutter made him hard to see.Solution:Keep head on swivel in pattern.  Possibly check ads-b display for at least a count of traffic in the air near the airport.
M20J pilot reported that while making a 45-degree entry to the downwind leg in traffic pattern; a near midair collision occurred with a departing aircraft in the crosswind leg which had not announced its takeoff.